Aerobic Exercise Training in Post-Polio Syndrome: Process Evaluation of a Randomized Controlled Trial.

PubMed

Voorn, Eric L; Koopman, Fieke S; Brehm, Merel A; Beelen, Anita; de Haan, Arnold; Gerrits, Karin H L; Nollet, Frans

2016-01-01

To explore reasons for the lack of efficacy of a high intensity aerobic exercise program in post-polio syndrome (PPS) on cardiorespiratory fitness by evaluating adherence to the training program and effects on muscle function. A process evaluation using data from an RCT. Forty-four severely fatigued individuals with PPS were randomized to exercise therapy (n = 22) or usual care (n = 22). Participants in the exercise group were instructed to exercise 3 times weekly for 4 months on a bicycle ergometer (60-70% heart rate reserve). The attendance rate was high (median 89%). None of the participants trained within the target heart rate range during >75% of the designated time. Instead, participants exercised at lower intensities, though still around the anaerobic threshold (AT) most of the time. Muscle function did not improve in the exercise group. Our results suggest that severely fatigued individuals with PPS cannot adhere to a high intensity aerobic exercise program on a cycle ergometer. Despite exercise intensities around the AT, lower extremity muscle function nor cardiorespiratory fitness improved. Improving the aerobic capacity in PPS is difficult through exercise primarily focusing on the lower extremities, and may require a more individualized approach, including the use of other large muscle groups instead. Netherlands National Trial Register NTR1371.

Novel metabolic attributes of the genus cyanothece, comprising a group of unicellular nitrogen-fixing Cyanothece.

PubMed

Bandyopadhyay, Anindita; Elvitigala, Thanura; Welsh, Eric; Stöckel, Jana; Liberton, Michelle; Min, Hongtao; Sherman, Louis A; Pakrasi, Himadri B

2011-01-01

The genus Cyanothece comprises unicellular cyanobacteria that are morphologically diverse and ecologically versatile. Studies over the last decade have established members of this genus to be important components of the marine ecosystem, contributing significantly to the nitrogen and carbon cycle. System-level studies of Cyanothece sp. ATCC 51142, a prototypic member of this group, revealed many interesting metabolic attributes. To identify the metabolic traits that define this class of cyanobacteria, five additional Cyanothece strains were sequenced to completion. The presence of a large, contiguous nitrogenase gene cluster and the ability to carry out aerobic nitrogen fixation distinguish Cyanothece as a genus of unicellular, aerobic nitrogen-fixing cyanobacteria. Cyanothece cells can create an anoxic intracellular environment at night, allowing oxygen-sensitive processes to take place in these oxygenic organisms. Large carbohydrate reserves accumulate in the cells during the day, ensuring sufficient energy for the processes that require the anoxic phase of the cells. Our study indicates that this genus maintains a plastic genome, incorporating new metabolic capabilities while simultaneously retaining archaic metabolic traits, a unique combination which provides the flexibility to adapt to various ecological and environmental conditions. Rearrangement of the nitrogenase cluster in Cyanothece sp. strain 7425 and the concomitant loss of its aerobic nitrogen-fixing ability suggest that a similar mechanism might have been at play in cyanobacterial strains that eventually lost their nitrogen-fixing ability. The unicellular cyanobacterial genus Cyanothece has significant roles in the nitrogen cycle in aquatic and terrestrial environments. Cyanothece sp. ATCC 51142 was extensively studied over the last decade and has emerged as an important model photosynthetic microbe for bioenergy production. To expand our understanding of the distinctive metabolic capabilities of this cyanobacterial group, we analyzed the genome sequences of five additional Cyanothece strains from different geographical habitats, exhibiting diverse morphological and physiological attributes. These strains exhibit high rates of N(2) fixation and H(2) production under aerobic conditions. They can generate copious amounts of carbohydrates that are stored in large starch-like granules and facilitate energy-intensive processes during the dark, anoxic phase of the cells. The genomes of some Cyanothece strains are quite unique in that there are linear elements in addition to a large circular chromosome. Our study provides novel insights into the metabolism of this class of unicellular nitrogen-fixing cyanobacteria.

Aerobic Exercise: Top 10 Reasons to Get Physical

MedlinePlus

... can help you live longer and healthier. Need motivation? See how aerobic exercise affects your heart, lungs and blood flow. Then get moving and start reaping the rewards. During aerobic activity, you repeatedly move large muscles ...

Novel Metabolic Attributes of the Genus Cyanothece, Comprising a Group of Unicellular Nitrogen-Fixing Cyanobacteria

PubMed Central

Bandyopadhyay, Anindita; Elvitigala, Thanura; Welsh, Eric; Stöckel, Jana; Liberton, Michelle; Min, Hongtao; Sherman, Louis A.; Pakrasi, Himadri B.

2011-01-01

ABSTRACT The genus Cyanothece comprises unicellular cyanobacteria that are morphologically diverse and ecologically versatile. Studies over the last decade have established members of this genus to be important components of the marine ecosystem, contributing significantly to the nitrogen and carbon cycle. System-level studies of Cyanothece sp. ATCC 51142, a prototypic member of this group, revealed many interesting metabolic attributes. To identify the metabolic traits that define this class of cyanobacteria, five additional Cyanothece strains were sequenced to completion. The presence of a large, contiguous nitrogenase gene cluster and the ability to carry out aerobic nitrogen fixation distinguish Cyanothece as a genus of unicellular, aerobic nitrogen-fixing cyanobacteria. Cyanothece cells can create an anoxic intracellular environment at night, allowing oxygen-sensitive processes to take place in these oxygenic organisms. Large carbohydrate reserves accumulate in the cells during the day, ensuring sufficient energy for the processes that require the anoxic phase of the cells. Our study indicates that this genus maintains a plastic genome, incorporating new metabolic capabilities while simultaneously retaining archaic metabolic traits, a unique combination which provides the flexibility to adapt to various ecological and environmental conditions. Rearrangement of the nitrogenase cluster in Cyanothece sp. strain 7425 and the concomitant loss of its aerobic nitrogen-fixing ability suggest that a similar mechanism might have been at play in cyanobacterial strains that eventually lost their nitrogen-fixing ability. PMID:21972240

Stabilization of waste-activated sludge through the anoxic-aerobic digestion process.

PubMed

Hashimoto, S; Fujita, M; Terai, K

1982-08-01

During the aerobic digestion process, the nitrogen which had been embedded in the activated sludge is solubilized to form ammoniacal and nitric nitrogen which are in turn transferred to the liquor and cause the increase of nitrogen loading in the sewage treatment plant. In this study, the anoxic-aerobic sludge digestion system which is a modified form of the conventional aerobic sludge digestion is made up of aerobic and anoxic tanks and are designed to remove both the volatile suspended solids and the total nitrogen (TN) simultaneously. The removal efficiencies of both VSS and TN were investigated by feeding waste-activated sludge continuously and semicontinuously. The maximum percent reduction of both VSS and TN was achieved at a Q(r)/Q(s) ratio of 2 in the continuous process. The semicontinuous process was used to improve the nitrogen removal efficiency further. In the semicontinuous process, the VSS reduction efficiency as well as the nitrogen removal efficiency increased remarkably under a constant Q(r)/Q(s) ratio of 2. This process also achieved a VSS reduction efficiency higher than the aerobic digestion process (control). It was suggested that the additional anoxic tank enhanced the sludge digestion. Furthermore, the anoxic-aerobic digestion system can be applied to other treatment media like the primary sludge, industrial sludge, animal manure, etc.

Controlling calcium precipitation in an integrated anaerobic-aerobic treatment system of a "zero-discharge" paper mill.

PubMed

van Lier, J B; Boncz, M A

2002-01-01

The pulp and paper industry uses significant amounts of water and energy for the paper production process. Closing the water cycles in this industry, therefore, promises large benefits for the environment and has the potential of huge cost savings for the industry. Closing the water cycle on the other hand also introduces problems with process water quality, quality of the end-product and scaling, owing to increased water contamination. An inline treatment system is discussed in which anaerobic-aerobic bioreactors perform a central role for removing both organic and inorganic pollutants from the process water cycle. In the proposed set-up, the organic compounds are converted to methane gas and reused for energy supply, while sulphur compounds are stripped from the process cycle and calcium carbonate is removed by precipitation. Improved control of the treatment system will direct the inorganic precipitates to a location where it does not adversely affect paper production and process water treatment. A simulation program for triggering and controlling CaCO3 precipitation was developed that takes both biological conversions and all relevant chemical equilibria in the system into account. Simulation results are in good agreement with data gathered in a full-scale "zero-emission" paper plant and indicate that control of CaCO3 precipitation can be improved, e.g. in the aerobic post-treatment. Alternatively, a separate precipitation unit could be considered.

Measurement Agreement between Estimates of Aerobic Fitness in Youth: The Impact of Body Mass Index

ERIC Educational Resources Information Center

Saint-Maurice, Pedro F.; Welk, Gregory J.; Laurson, Kelly R.; Brown, Dale D.

2014-01-01

Purpose: The purpose of this study was to examine the impact of body mass index (BMI) on the agreement between aerobic capacity estimates from different Progressive Aerobic Cardiorespiratory Endurance Run (PACER) equations and the Mile Run Test. Method: The agreement between 2 different tests of aerobic capacity was examined on a large data set…

Stabilization of waste-activated sludge through the anoxic-aerobic digestion process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hashimoto, S.; Fujita, M.; Terai, K.

1982-08-01

During the aerobic digestion process, the nitrogen which had been embedded in the activated sludge is solubilized to form ammoniacal and nitric nitrogen which are in turn transferred to the liquor and cause the increase of nitrogen loading in the sewage treatment plant. In this study, the anoxic-aerobic sludge digestion system which is a modified form of the conventional aerobic sludge digestion is made up of aerobic and anoxic tanks and are designed to remove both the volatile suspended solids and the total nitrogen (TN) simultaneously. The removal efficiencies of both VSS and TN were investigated by feeding waste-activated sludgemore » continuously and semicontinuously. The maximum percent reduction of both VSS and TN was achieved at a Q /SUB r/ /Q /SUB s/ ratio of 2 in the continuous process. The semicontinuous process was used to improve the nitrogen removal efficiency further. In the semicontinuous process, the VSS reduction efficiency as well as the nitrogen removal efficiency increased remarkably under a constant Q /SUB r/ /Q /SUB s/ ratio of 2. This process also achieved a VSS reduction efficiency higher than the aerobic digestion process (control). It was suggested that the additional anoxic tank enhanced the sludge digestion. Furthermore, the anoxic-aerobic digestion system can be applied to other treatment media like the primary sludge, industrial sludge, animal manure, etc.« less

Enhancing Cognitive Training Through Aerobic Exercise After a First Schizophrenia Episode: Theoretical Conception and Pilot Study

PubMed Central

Nuechterlein, Keith H.; Ventura, Joseph; McEwen, Sarah C.; Gretchen-Doorly, Denise; Vinogradov, Sophia; Subotnik, Kenneth L.

2016-01-01

Cognitive training (CT) and aerobic exercise have separately shown promise for improving cognitive deficits in schizophrenia. Aerobic exercise releases brain-derived neurotrophic factor, which promotes synaptic plasticity and neurogenesis. Thus, aerobic exercise provides a neurotrophic platform for neuroplasticity-based CT. The combination of aerobic exercise and CT may yield more robust effects than CT alone, particularly in the initial course of schizophrenia. In a pilot study, 7 patients with a recent onset of schizophrenia were assigned to Cognitive Training & Exercise (CT&E) and 9 to CT alone for a 10-week period. Posit Science programs were used for CT. Neurocognitive training focused on tuning neural circuits related to perceptual processing and verbal learning and memory. Social cognitive training used the same learning principles with social and affective stimuli. Both groups participated in these training sessions 2d/wk, 2h/d. The CT&E group also participated in an aerobic conditioning program for 30 minutes at our clinic 2d/wk and at home 2d/wk. The effect size for improvement in the MATRICS Consensus Cognitive Battery Overall Composite score for CT&E patients relative to CT patients was large. Functional outcome, particularly independent living skills, also tended to improve more in the CT&E than in the CT group. Muscular endurance, cardiovascular fitness, and diastolic blood pressure also showed relative improvement in the CT&E compared to the CT group. These encouraging pilot study findings support the promise of combining CT and aerobic exercise to improve the early course of schizophrenia. PMID:27460618

FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramin Yazdani; Jeff Kieffer; Heather Akau

2003-12-01

The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches for carbon sequestration and greenhouse emission control. The overall objective is to manage landfill solid waste for rapid waste decomposition and maximum landfill gas generation and capture for carbon sequestration and greenhouse emission control. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes ofmore » air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. Liquid addition has commenced in the 3.5-acre anaerobic cell and the 6-acre anaerobic cell. Construction of the 2.5-acre aerobic cell and biofilter has been completed. The remaining task to be completed is to test the biofilter prior to operation, which is currently anticipated to begin in January 2004. The current project status and preliminary monitoring results are summarized in this report.« less

Aerobic Exercise Training in Post-Polio Syndrome: Process Evaluation of a Randomized Controlled Trial

PubMed Central

Voorn, Eric L.; Koopman, Fieke S.; Brehm, Merel A.; Beelen, Anita; de Haan, Arnold; Gerrits, Karin H. L.; Nollet, Frans

2016-01-01

Objective To explore reasons for the lack of efficacy of a high intensity aerobic exercise program in post-polio syndrome (PPS) on cardiorespiratory fitness by evaluating adherence to the training program and effects on muscle function. Design A process evaluation using data from an RCT. Patients Forty-four severely fatigued individuals with PPS were randomized to exercise therapy (n = 22) or usual care (n = 22). Methods Participants in the exercise group were instructed to exercise 3 times weekly for 4 months on a bicycle ergometer (60–70% heart rate reserve). Results The attendance rate was high (median 89%). None of the participants trained within the target heart rate range during >75% of the designated time. Instead, participants exercised at lower intensities, though still around the anaerobic threshold (AT) most of the time. Muscle function did not improve in the exercise group. Conclusion Our results suggest that severely fatigued individuals with PPS cannot adhere to a high intensity aerobic exercise program on a cycle ergometer. Despite exercise intensities around the AT, lower extremity muscle function nor cardiorespiratory fitness improved. Improving the aerobic capacity in PPS is difficult through exercise primarily focusing on the lower extremities, and may require a more individualized approach, including the use of other large muscle groups instead. Trial Registration Netherlands National Trial Register NTR1371 PMID:27419388

Aerobic biodegradation process of petroleum and pathway of main compounds in water flooding well of Dagang oil field.

PubMed

Cai, Minmin; Yao, Jun; Yang, Huaijun; Wang, Ruixia; Masakorala, Kanaji

2013-09-01

Aerobic biodegradation of crude oil and its pathways were investigated via in vitro culture and GC-MS analysis in water flooding wells of Dagang oil field. The in vitro aerobic culture lasted 90 days when 99.0% of n-alkanes and 43.03-99.9% of PAHs were degraded and the biomarkers and their ratios were changed. The spectra of components in the residual oil showed the similar biodegradation between aerobic process of 90 days and degradation in reservoir which may last for some millions years, and the potential of serious aerobic biodegradation of petroleum in reservoir. 24 Metabolites compounds were separated and identified from aerobic culture, including fatty acid, naphthenic acid, aromatic carboxylic acid, unsaturated acid, alcohols, ketones and aldehydes. The pathways of alkanes and aromatics were proposed, which suggests that oxidation of hydrocarbon to organic acid is an important process in the aerobic biodegradation of petroleum. Copyright © 2013 Elsevier Ltd. All rights reserved.

Aerobic sludge granulation for simultaneous anaerobic decolorization and aerobic aromatic amines mineralization for azo dye wastewater treatment.

PubMed

Yan, Lawrence K Q; Fung, Ka Y; Ng, Ka M

2018-06-01

In this study, the capability of using aerobic granules to undergo simultaneous anaerobic decolorization and aerobic aromatic amines degradation was demonstrated for azo dye wastewater treatment. An integrated acclimation-granulation process was devised, with Mordant Orange 1 as the model pollutant. Performance tests were carried out in a batch column reactor to evaluate the effect of various operating parameters. The optimal condition was to use 1.0-1.7 mm (1.51 ± 0.33 mm) granules, 5 g/L biomass, and 4000 mg/L organics as nutrient; and supplement the wastewater with 1  mg/L dissolved oxygen. This led to a dye mineralization of 61 ± 2%, an anaerobic dye removal of 88 ± 1%, and an aerobic aromatic amines removal of 70 ± 3% within 48 h. This study showed that simultaneous anaerobic/aerobic process by aerobic granules could be a possible alternative to the conventional activated sludge process.

Membrane thickening aerobic digestion processes.

PubMed

Woo, Bryen

2014-01-01

Sludge management accounts for approximately 60% of the total wastewater treatment plant expenditure and laws for sludge disposal are becoming increasingly stringent, therefore much consideration is required when designing a solids handling process. A membrane thickening aerobic digestion process integrates a controlled aerobic digestion process with pre-thickening waste activated sludge using membrane technology. This process typically features an anoxic tank, an aerated membrane thickener operating in loop with a first-stage digester followed by second-stage digestion. Membrane thickening aerobic digestion processes can handle sludge from any liquid treatment process and is best for facilities obligated to meet low total phosphorus and nitrogen discharge limits. Membrane thickening aerobic digestion processes offer many advantages including: producing a reusable quality permeate with minimal levels of total phosphorus and nitrogen that can be recycled to the head works of a plant, protecting the performance of a biological nutrient removal liquid treatment process without requiring chemical addition, providing reliable thickening up to 4% solids concentration without the use of polymers or attention to decanting, increasing sludge storage capacities in existing tanks, minimizing the footprint of new tanks, reducing disposal costs, and providing Class B stabilization.

Factors Driving Potential Ammonia Oxidation in Canadian Arctic Ecosystems: Does Spatial Scale Matter?

PubMed Central

Banerjee, Samiran

2012-01-01

Ammonia oxidation is a major process in nitrogen cycling, and it plays a key role in nitrogen limited soil ecosystems such as those in the arctic. Although mm-scale spatial dependency of ammonia oxidizers has been investigated, little is known about the field-scale spatial dependency of aerobic ammonia oxidation processes and ammonia-oxidizing archaeal and bacterial communities, particularly in arctic soils. The purpose of this study was to explore the drivers of ammonia oxidation at the field scale in cryosols (soils with permafrost within 1 m of the surface). We measured aerobic ammonia oxidation potential (both autotrophic and heterotrophic) and functional gene abundance (bacterial amoA and archaeal amoA) in 279 soil samples collected from three arctic ecosystems. The variability associated with quantifying genes was substantially less than the spatial variability observed in these soils, suggesting that molecular methods can be used reliably evaluate spatial dependency in arctic ecosystems. Ammonia-oxidizing archaeal and bacterial communities and aerobic ammonia oxidation were spatially autocorrelated. Gene abundances were spatially structured within 4 m, whereas biochemical processes were structured within 40 m. Ammonia oxidation was driven at small scales (<1m) by moisture and total organic carbon, whereas gene abundance and other edaphic factors drove ammonia oxidation at medium (1 to 10 m) and large (10 to 100 m) scales. In these arctic soils heterotrophs contributed between 29 and 47% of total ammonia oxidation potential. The spatial scale for aerobic ammonia oxidation genes differed from potential ammonia oxidation, suggesting that in arctic ecosystems edaphic, rather than genetic, factors are an important control on ammonia oxidation. PMID:22081570

Comparing the effects of three pre-treatment disintegration techniques on aerobic sludge digestion: biodegradability enhancement and microbial community monitoring by PCR-DGGE.

PubMed

Jaziri, Kais; Casellas, Magali; Dagot, Christophe

2012-06-01

The objectives of this work were to compare and investigate the effect of three activated sludge disintegration processes before aerobic sludge digestion on 1) aerobic biodegradability enhancement and 2) microbial community evolution using the polymerase chain reaction-denaturant gel gradient electrophoresis (PCR-DGGE) technique. The comparison of three disintegration processes: thermal treatment (95 degrees C, 2h), sonication (100,000 kJ/kgTS) and ozonation (0.108 g O3/gTS) showed that the disintegration processes acted differently according to the composition of the soluble phase and to the DNA damage. Thermal treatment led to significant protein solubilization and to DNA modification. Sonication and ozonation resulted in similar soluble phase compositions and did not lead to any DNA modifications. During activated sludge aerobic digestion, intrinsic biodegradability enhancement was observed for thermal and ozone activated sludge pre-treatments. The analysis of the DGGE patterns at the end of aerobic digestion showed that population diversity was affected by both the aerobic digestion and the pre-treatment. The dissimilarity percentages measured at the end of aerobic digestion in the control sample and in the treated sludge were equal to 22, 25 and 20% for thermal treatment, sonication and ozonation respectively. This study indicated that PCR-DGGE could be a useful tool for the comparison of disintegration processes before and after aerobic digestion.

Anaerobic digestion of dairy cattle manure autoheated by aerobic pretreatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Achkari-Begdouri, A.

1989-01-01

A novel way to heat anaerobic digesters was investigated. Dairy cattle manure was autoheated by an aerobic pretreatment process and then fed to the anaerobic digester. Important physical properties of the dairy cattle manure were determined. These included bulk density, specific heat, thermal conductivity and the rheological properties; consistency coefficient, behavior index and apparent viscosity. These parameters were used to calculate the overall heat transfer coefficients, and to estimate the heat losses from the aerobic reactor to the outside environment. The total energy balance of the aerobic treatment system was then established. An optimization study of the main parameters influencingmore » the autoheating process showed that the total solids, the air flow rate and the stirring speed for operation of the aerobic pretreatment should be approximately 7%, 70 L/H and 1,400 rpm respectively. Temperatures as high as 65C were reached in 40 hours of aerobic treatment. At the above recommended levels of total solids, the air flow rate and the stirring speed, there was little difference in the energy requirements for heating the influent by aeration and heating the influent by a conventional heating system. In addition to the temperature increase, the aerobic pretreatment assisted in balancing the anaerobic digestion process and increased the methanogenesis of the dairy cattle manure. Despite the 8% decomposition of organic matter that occurred during the aerobic pretreatment process, methane production of the digester started with the aerobically heated manure was significantly higher (at least 20% higher) than of the digester started with conventionally heated manure. The aerobic system successfully autoheated the dairy cattle manure with an energy cost equal to that of conventionally heated influent.« less

Influence of aerobic and anoxic microenvironments on polyhydroxyalkanoates (PHA) production from food waste and acidogenic effluents using aerobic consortia.

PubMed

Reddy, M Venkateswar; Mohan, S Venkata

2012-01-01

The functional role of aerobic and anoxic microenvironments on polyhydroxyalkanoates (PHA) production using food waste (UFW) and effluents from acidogenic biohydrogen production process (FFW) were studied employing aerobic mixed culture as biocatalyst. Anoxic microenvironment documented higher PHA production, while aerobic microenvironment showed higher substrate degradation. FFW showed higher PHA accumulation (39.6%) than UFW (35.6%) due to ready availability of precursors (fatty acids). Higher fraction of poly-3-hydroxy butyrate (PHB) was observed compared to poly-3-hydroxy valerate (PHV) in the accumulated PHA in the form of co-polymer [P3(HB-co-HV)]. Dehydrogenase, phosphatase and protease enzymatic activities were monitored during process operation. Integration with fermentative biohydrogen production yielded additional substrate degradation under both aerobic (78%) and anoxic (72%) microenvironments apart from PHA production. Microbial community analysis documented the presence of aerobic and facultative organisms capable of producing PHA. Integration strategy showed feasibility of producing hydrogen along with PHA by consuming fatty acids generated during acidogenic process in association with increased treatment efficiency. Copyright © 2011 Elsevier Ltd. All rights reserved.

Enhancing Cognitive Training Through Aerobic Exercise After a First Schizophrenia Episode: Theoretical Conception and Pilot Study.

PubMed

Nuechterlein, Keith H; Ventura, Joseph; McEwen, Sarah C; Gretchen-Doorly, Denise; Vinogradov, Sophia; Subotnik, Kenneth L

2016-07-01

Cognitive training (CT) and aerobic exercise have separately shown promise for improving cognitive deficits in schizophrenia. Aerobic exercise releases brain-derived neurotrophic factor, which promotes synaptic plasticity and neurogenesis. Thus, aerobic exercise provides a neurotrophic platform for neuroplasticity-based CT. The combination of aerobic exercise and CT may yield more robust effects than CT alone, particularly in the initial course of schizophrenia. In a pilot study, 7 patients with a recent onset of schizophrenia were assigned to Cognitive Training & Exercise (CT&E) and 9 to CT alone for a 10-week period. Posit Science programs were used for CT. Neurocognitive training focused on tuning neural circuits related to perceptual processing and verbal learning and memory. Social cognitive training used the same learning principles with social and affective stimuli. Both groups participated in these training sessions 2d/wk, 2h/d. The CT&E group also participated in an aerobic conditioning program for 30 minutes at our clinic 2d/wk and at home 2d/wk. The effect size for improvement in the MATRICS Consensus Cognitive Battery Overall Composite score for CT&E patients relative to CT patients was large. Functional outcome, particularly independent living skills, also tended to improve more in the CT&E than in the CT group. Muscular endurance, cardiovascular fitness, and diastolic blood pressure also showed relative improvement in the CT&E compared to the CT group. These encouraging pilot study findings support the promise of combining CT and aerobic exercise to improve the early course of schizophrenia. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Transcriptional Regulation of Aerobic Metabolism in Pichia pastoris Fermentation

PubMed Central

Zhang, Biao; Li, Baizhi; Chen, Dai; Zong, Jie; Sun, Fei; Qu, Huixin; Liang, Chongyang

2016-01-01

In this study, we investigated the classical fermentation process in Pichia pastoris based on transcriptomics. We utilized methanol in pichia yeast cell as the focus of our study, based on two key steps: limiting carbon source replacement (from glycerol to methonal) and fermentative production of exogenous proteins. In the former, the core differential genes in co-expression net point to initiation of aerobic metabolism and generation of peroxisome. The transmission electron microscope (TEM) results showed that yeast gradually adapted methanol induction to increased cell volume, and decreased density, via large number of peroxisomes. In the fermentative production of exogenous proteins, the Gene Ontology (GO) mapping results show that PAS_chr2-1_0582 played a vital role in regulating aerobic metabolic drift. In order to confirm the above results, we disrupted PAS_chr2-1_0582 by homologous recombination. Alcohol consumption was equivalent to one fifth of the normal control, and fewer peroxisomes were observed in Δ0582 strain following methanol induction. In this study we determined the important core genes and GO terms regulating aerobic metabolic drift in Pichia, as well as developing new perspectives for the continued development within this field. PMID:27537181

Two-stage anaerobic and post-aerobic mesophilic digestion of sewage sludge: Analysis of process performance and hygienization potential.

PubMed

Tomei, M Concetta; Mosca Angelucci, Domenica; Levantesi, Caterina

2016-03-01

Sequential anaerobic-aerobic digestion has been demonstrated to be effective for enhanced sludge stabilization, in terms of increased solid reduction and improvement of sludge dewaterability. In this study, we propose a modified version of the sequential anaerobic-aerobic digestion process by operating the aerobic step under mesophilic conditions (T=37 °C), in order to improve the aerobic degradation kinetics of soluble and particulate chemical oxygen demand (COD). Process performance has been assessed in terms of "classical parameters" such as volatile solids (VS) removal, biogas production, COD removal, nitrogen species, and polysaccharide and protein fate. The aerobic step was operated under intermittent aeration to achieve nitrogen removal. Aerobic mesophilic conditions consistently increased VS removal, providing 32% additional removal vs. 20% at 20 °C. Similar results were obtained for nitrogen removal, increasing from 64% up to 99% at the higher temperature. Improved sludge dewaterability was also observed with a capillary suction time decrease of ~50% during the mesophilic aerobic step. This finding may be attributable to the decreased protein content in the aerobic digested sludge. The post-aerobic digestion exerted a positive effect on the reduction of microbial indicators while no consistent improvement of hygienization related to the increased temperature was observed. The techno-economic analysis of the proposed digestion layout showed a net cost saving for sludge disposal estimated in the range of 28-35% in comparison to the single-phase anaerobic digestion. Copyright © 2015 Elsevier B.V. All rights reserved.

Correlates of meeting the combined and independent aerobic and strength exercise guidelines in hematologic cancer survivors.

PubMed

Vallerand, James R; Rhodes, Ryan E; Walker, Gordon J; Courneya, Kerry S

2017-03-28

Most previous research on the correlates of physical activity has examined the aerobic or strength exercise guidelines separately. Such an approach does not allow an examination of the correlates of meeting the combined guidelines versus a single guideline, or one guideline versus the other. Here, we report the prevalence and correlates of meeting the combined and independent exercise guidelines in hematologic cancer survivors (HCS). In a population-based, cross-sectional survey of 606 HCS from Alberta, Canada using a mailed questionnaire, we obtained separate assessments of aerobic and strength exercise behaviors, as well as separate assessments for motivations, regulations, and reflective processes using the multi-process action control framework (M-PAC). Overall, 22% of HCS met the combined exercise guideline, 22% met aerobic-only, 10% met strength-only, and 46% met neither exercise guideline. HCS were more likely to meet the combined guideline over the aerobic-only guideline if they had no children living at home, and over both the aerobic and strength-only guidelines if they had completed university. As hypothesized, those meeting the combined guideline also had a more favorable strength-specific M-PAC profile (i.e., motivations, regulations, and reflective processes) than those meeting the aerobic-only guideline, and a more favorable aerobic-specific M-PAC profile than those meeting the strength-only guideline. Interestingly and unexpectedly, HCS meeting the combined guidelines also reported significantly greater aerobic-specific perceived control, planning, and obligation/regret than those meeting the aerobic-only guideline, and greater strength-specific perceived control, planning, and obligation/regret than those meeting the strength-only guideline. Few HCS are meeting the combined exercise guidelines. M-PAC based variables are strong correlates of meeting the combined guidelines compared to aerobic or strength only guidelines. Strategies to help HCS meet the combined guidelines may need to promote more favorable behavioral regulations and reflective processes for both types of exercise rather than just the type of exercise in which HCS are deficient.

Microbial communities in the functional areas of a biofilm reactor with anaerobic-aerobic process for oily wastewater treatment.

PubMed

Li, Jianhua; Sun, Shanshan; Yan, Ping; Fang, Li; Yu, Yang; Xiang, Yangdong; Wang, Di; Gong, Yejing; Gong, Yanjun; Zhang, Zhongzhi

2017-08-01

Microbial communities in the functional areas of biofilm reactors with large height-diameter ratio using the anaerobic-aerobic (A/O) reflux process was investigated to treat heavy oil refinery wastewater without pretreatment. In the process, chemical oxygen demand (COD) and total nitrogen (TN) removal reached 93.2% and 82.8%, and the anaerobic biofilm reactor was responsible for 95% and 99%, respectively. Areas for hydrolysis acidification and acetic acid production, methane production, and COD recovery were obvious in the anaerobic reactor. Among all areas, area for hydrolysis acidification and acetic acid production was the key factor to improve COD removal efficiency. High throughput sequencing of 16S rDNA gene showed that the native community was mainly composed of functional groups for hydrocarbon degradation, syntrophic bacteria union body, methanogenesis, nitrification, denitrification, and sulfate reduction. The deviations between predicted values and actual COD and TN removal were less than 5% in the optimal prediction model. Copyright © 2017 Elsevier Ltd. All rights reserved.

Improving anaerobic and aerobic degradation by ultrasonic disintegration of biomass.

PubMed

Neis, Uwe; Nickel, Klaus; Lundén, Anna

2008-11-01

Biological cell lysis is known to be the rate-limiting step of anaerobic biosolids degradation. Due to the slow pace by which this reaction occurs, it is necessary to equip treatment plants with large digesters or alternatively incorporate technological aids. High-power ultrasound used to disintegrate bacterial cells has been utilized as a pre-treatment process prior to anaerobic digestion. Through this application, as seen on pilot- and full-scales, it is possible to attain up to 30% more biogas, an increase in VS-destruction of up to 30% and a reduced sludge mass for disposal. Utilizing ultrasound technology in aerobic applications is a new and innovative approach. Improved denitrification through a more readily available internal carbon source, and less excess sludge mass can be traced to the positive effects that sonication of sludge has on the overall biological wastewater treatment process. Reference full-scale installations suggest that the technology is both technically feasible and economically sound.

Edward F. Adolph Distinguished Lecture: The remarkable anti-aging effects of aerobic exercise on systemic arteries

PubMed Central

2014-01-01

Cardiovascular diseases (CVD) remain the leading cause of morbidity and mortality in modern societies, and advancing age is the major risk factor for CVD. Arterial dysfunction, characterized by large elastic artery stiffening and endothelial dysfunction, is the key event leading to age-associated CVD. Our work shows that regular aerobic exercise inhibits large elastic artery stiffening with aging (optimizes arterial compliance) and preserves endothelial function. Importantly, among previously sedentary late middle-aged and older adults, aerobic exercise improves arterial stiffness and enhances endothelial function in most groups and, therefore, also can be considered a treatment for age-associated arterial dysfunction. The mechanisms by which regular aerobic exercise destiffens large elastic arteries are incompletely understood, but existing evidence suggests that reductions in oxidative stress associated with decreases in both adventitial collagen (fibrosis) and advanced glycation end-products (structural protein cross-linking molecules), play a key role. Aerobic exercise preserves endothelial function with aging by maintaining nitric oxide bioavailability via suppression of excessive superoxide-associated oxidative stress, and by inhibiting the development of chronic low-grade vascular inflammation. Recent work from our laboratory supports the novel hypothesis that aerobic exercise may exert these beneficial effects by directly inducing protection to aging arteries against multiple adverse factors to which they are chronically exposed. Regular aerobic exercise should be viewed as a “first line” strategy for prevention and treatment of arterial aging and a vital component of a contemporary public health approach for reducing the projected increase in population CVD burden. PMID:24855137

Edward F. Adolph Distinguished Lecture: The remarkable anti-aging effects of aerobic exercise on systemic arteries.

PubMed

Seals, Douglas R

2014-09-01

Cardiovascular diseases (CVD) remain the leading cause of morbidity and mortality in modern societies, and advancing age is the major risk factor for CVD. Arterial dysfunction, characterized by large elastic artery stiffening and endothelial dysfunction, is the key event leading to age-associated CVD. Our work shows that regular aerobic exercise inhibits large elastic artery stiffening with aging (optimizes arterial compliance) and preserves endothelial function. Importantly, among previously sedentary late middle-aged and older adults, aerobic exercise improves arterial stiffness and enhances endothelial function in most groups and, therefore, also can be considered a treatment for age-associated arterial dysfunction. The mechanisms by which regular aerobic exercise destiffens large elastic arteries are incompletely understood, but existing evidence suggests that reductions in oxidative stress associated with decreases in both adventitial collagen (fibrosis) and advanced glycation end-products (structural protein cross-linking molecules), play a key role. Aerobic exercise preserves endothelial function with aging by maintaining nitric oxide bioavailability via suppression of excessive superoxide-associated oxidative stress, and by inhibiting the development of chronic low-grade vascular inflammation. Recent work from our laboratory supports the novel hypothesis that aerobic exercise may exert these beneficial effects by directly inducing protection to aging arteries against multiple adverse factors to which they are chronically exposed. Regular aerobic exercise should be viewed as a "first line" strategy for prevention and treatment of arterial aging and a vital component of a contemporary public health approach for reducing the projected increase in population CVD burden. Copyright © 2014 the American Physiological Society.

Treatment of raw and ozonated oil sands process-affected water under decoupled denitrifying anoxic and nitrifying aerobic conditions: a comparative study.

PubMed

Xue, Jinkai; Zhang, Yanyan; Liu, Yang; Gamal El-Din, Mohamed

2016-11-01

Batch experiments were performed to evaluate biodegradation of raw and ozonated oil sands process-affected water (OSPW) under denitrifying anoxic and nitrifying aerobic conditions for 33 days. The results showed both the anoxic and aerobic conditions are effective in degrading OSPW classical and oxidized naphthenic acids (NAs) with the aerobic conditions demonstrating higher removal efficiency. The reactors under nitrifying aerobic condition reduced the total classical NAs of raw OSPW by 69.1 %, with better efficiency for species of higher hydrophobicity. Compared with conventional aerobic reactor, nitrifying aerobic condition substantially shortened the NA degradation half-life to 16 days. The mild-dose ozonation remarkably accelerated the subsequent aerobic biodegradation of classical NAs within the first 14 days, especially for those with long carbon chains. Moreover, the ozone pretreatment enhanced the biological removal of OSPW classical NAs by leaving a considerably lower final residual concentration of 10.4 mg/L under anoxic conditions, and 5.7 mg/L under aerobic conditions. The combination of ozonation and nitrifying aerobic biodegradation removed total classical NAs by 76.5 % and total oxy-NAs (O3-O6) by 23.6 %. 454 Pyrosequencing revealed that microbial species capable of degrading recalcitrant hydrocarbons were dominant in all reactors. The most abundant genus in the raw and ozonated anoxic reactors was Thauera (~56 % in the raw OSPW anoxic reactor, and ~65 % in the ozonated OSPW anoxic reactor); whereas Rhodanobacter (~40 %) and Pseudomonas (~40 %) dominated the raw and ozonated aerobic reactors, respectively. Therefore, the combination of mild-dose ozone pretreatment and subsequent biological process could be a competent choice for OSPW treatment.

Evaluation of the Removal of Indicator Bacteria from Domestic Sludge Processed by Autothermal Thermophilic Aerobic Digestion (ATAD)

PubMed Central

Piterina, Anna V.; Bartlett, John; Pembroke, Tony J.

2010-01-01

The degradation of sludge solids in an insulated reactor during Autothermal Thermophilic Aerobic Digestion (ATAD) processing results in auto-heating, thermal treatment and total solids reduction, however, the ability to eliminate pathogenic organisms has not been analysed under large scale process conditions. We evaluated the ATAD process over a period of one year in a two stage, full scale Irish ATAD plant established in Killarney and treating mixed primary and secondary sludge, by examining the sludge microbiologically at various stages during and following ATAD processing to determine its ability to eliminate indicator organisms. Salmonella spp. (pathogen) and fecal-coliform (indicator) densities were well below the limits used to validate class A biosolids in the final product. Enteric pathogens present at inlet were deactivated during the ATAD process and were not detected in the final product using both traditional microbial culture and molecular phylogenetic techniques. A high DNase activity was detected in the bulk sludge during the thermophilic digestion stage which may be responsible for the rapid turn over of DNA from lysed cells and the removal of mobile DNA. These results offer assurance for the safe use of ATAD sludge as a soil supplement following processing. PMID:20948933

Evaluation of the removal of indicator bacteria from domestic sludge processed by Autothermal Thermophilic Aerobic Digestion (ATAD).

PubMed

Piterina, Anna V; Bartlett, John; Pembroke, Tony J

2010-09-01

The degradation of sludge solids in an insulated reactor during Autothermal Thermophilic Aerobic Digestion (ATAD) processing results in auto-heating, thermal treatment and total solids reduction, however, the ability to eliminate pathogenic organisms has not been analysed under large scale process conditions. We evaluated the ATAD process over a period of one year in a two stage, full scale Irish ATAD plant established in Killarney and treating mixed primary and secondary sludge, by examining the sludge microbiologically at various stages during and following ATAD processing to determine its ability to eliminate indicator organisms. Salmonella spp. (pathogen) and fecal-coliform (indicator) densities were well below the limits used to validate class A biosolids in the final product. Enteric pathogens present at inlet were deactivated during the ATAD process and were not detected in the final product using both traditional microbial culture and molecular phylogenetic techniques. A high DNase activity was detected in the bulk sludge during the thermophilic digestion stage which may be responsible for the rapid turn over of DNA from lysed cells and the removal of mobile DNA. These results offer assurance for the safe use of ATAD sludge as a soil supplement following processing.

Impact of aerobic acclimation on the nitrification performance and microbial community of landfill leachate sludge.

PubMed

Hira, Daisuke; Aiko, Nobuyuki; Yabuki, Yoshinori; Fujii, Takao

2018-03-01

Nitrogenous pollution of water is regarded as a global environmental problem, and nitrogen removal has become an important issue in wastewater treatment processes. Landfill leachate is a typical large source of nitrogenous wastewater. Although the characteristics of leachate vary according to the age of the landfill, leachates of mature landfill have high concentrations of nitrogenous compounds. Most nitrogen in these leachates is in the form of ammonium nitrogen. In this study, we investigated the bacterial community of sludge from a landfill leachate lagoon by pyrosequencing of the bacterial 16S rRNA gene. The sludge was acclimated in a laboratory-scale reactor with aeration using a mechanical stirrer to promote nitrification. On 149 days, nitrification was achieved and then the bacterial community was also analyzed. The bacterial community was also analyzed after nitrification was achieved. Pyrosequencing analyses revealed that the abundances of ammonia-oxidizing and nitrite-oxidizing bacteria were increased by acclimation and their total proportions increased to >15% of total biomass. Changes in the sulfate-reducing and sulfur-oxidizing bacteria were also observed during the acclimation process. The aerobic acclimation process enriched a nitrifying microbial community from the landfill leachate sludge. These results suggested that the aerobic acclimation is a processing method for the nitrification ammonium oxidizing throw the enrichment of nitrifiers. Improvement of this acclimation method would allow nitrogen removal from leachate by nitrification and sulfur denitrification. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aerobic exercise and other healthy lifestyle factors that influence vascular aging.

PubMed

Santos-Parker, Jessica R; LaRocca, Thomas J; Seals, Douglas R

2014-12-01

Cardiovascular diseases (CVDs) remain the leading cause of death in the United States and other modern societies. Advancing age is the major risk factor for CVD, primarily due to stiffening of the large elastic arteries and the development of vascular endothelial dysfunction. In contrast, regular aerobic exercise protects against the development of large elastic artery stiffness and vascular endothelial dysfunction with advancing age. Moreover, aerobic exercise interventions reduce arterial stiffness and restore vascular endothelial function in previously sedentary middle-aged/older adults. Aerobic exercise exerts its beneficial effects on arterial function by modulating structural proteins, reducing oxidative stress and inflammation, and restoring nitric oxide bioavailability. Aerobic exercise may also promote "resistance" against factors that reduce vascular function and increase CVD risk with age. Preventing excessive increases in abdominal adiposity, following healthy dietary practices, maintaining a low CVD risk factor profile, and, possibly, selective use of pharmaceuticals and nutraceuticals also play a major role in preserving vascular function with aging. Copyright © 2014 The American Physiological Society.

Aerobic exercise and other healthy lifestyle factors that influence vascular aging

PubMed Central

Santos-Parker, Jessica R.; LaRocca, Thomas J.

2014-01-01

Cardiovascular diseases (CVDs) remain the leading cause of death in the United States and other modern societies. Advancing age is the major risk factor for CVD, primarily due to stiffening of the large elastic arteries and the development of vascular endothelial dysfunction. In contrast, regular aerobic exercise protects against the development of large elastic artery stiffness and vascular endothelial dysfunction with advancing age. Moreover, aerobic exercise interventions reduce arterial stiffness and restore vascular endothelial function in previously sedentary middle-aged/older adults. Aerobic exercise exerts its beneficial effects on arterial function by modulating structural proteins, reducing oxidative stress and inflammation, and restoring nitric oxide bioavailability. Aerobic exercise may also promote “resistance” against factors that reduce vascular function and increase CVD risk with age. Preventing excessive increases in abdominal adiposity, following healthy dietary practices, maintaining a low CVD risk factor profile, and, possibly, selective use of pharmaceuticals and nutraceuticals also play a major role in preserving vascular function with aging. PMID:25434012

Pd-catalyzed aerobic oxidative annulation of cyclohexanones and 2-aminophenyl ketones: A direct approach to acridines

NASA Astrophysics Data System (ADS)

Mu, Wanlu; Li, Xiaowei; Wang, Longfei; Chen, Yong; Wu, Yanchao

2017-08-01

An efficient aerobic oxidative annulation of cyclohexanones and 2-aminophenyl ketones approach to substituted acridines, a structural motif for a large number of pharmaceuticals and functional materials is described. The key feature of this method is the use of oxygen as the sole oxidant and Pd catalyst, which resulting in the high regioselectivity with unsymmetrical meta-substituted cyclohexanones. The electron gap of the global redox condensation process is filled and the reaction efficiency is significantly promoted by O2 as a redox moderator. This protocol possesses many advantages such as using O2 as a cheap and nonhazardous oxidant, high regioselectivity and water as the only by-product, which meet the principle of green chemistry.

Transcriptional and metabolic response of recombinant Escherichia coli to spatial dissolved oxygen tension gradients simulated in a scale-down system.

PubMed

Lara, Alvaro R; Leal, Lidia; Flores, Noemí; Gosset, Guillermo; Bolívar, Francisco; Ramírez, Octavio T

2006-02-05

Escherichia coli, expressing recombinant green fluorescent protein (GFP), was subjected to dissolved oxygen tension (DOT) oscillations in a two-compartment system for simulating gradients that can occur in large-scale bioreactors. Cells were continuously circulated between the anaerobic (0% DOT) and aerobic (10% DOT) vessels of the scale-down system to mimic an overall circulation time of 50 s, and a mean residence time in the anaerobic and aerobic compartments of 33 and 17 s, respectively. Transcription levels of mixed acid fermentation genes (ldhA, poxB, frdD, ackA, adhE, pflD, and fdhF), measured by quantitative RT-PCR, increased between 1.5- to over 6-fold under oscillatory DOT compared to aerobic cultures (constant 10% DOT). In addition, the transcription level of fumB increased whereas it decreased for sucA and sucB, suggesting that the tricarboxylic acid cycle was functioning as two open branches. Gene transcription levels revealed that cytrochrome bd, which has higher affinity to oxygen but lower energy efficiency, was preferred over cytochrome bO3 in oscillatory DOT cultures. Post-transcriptional processing limited heterologous protein production in the scale-down system, as inferred from similar gfp transcription but 19% lower GFP concentration compared to aerobic cultures. Simulated DOT gradients also affected the transcription of genes of the glyoxylate shunt (aceA), of global regulators of aerobic and anaerobic metabolism (fnr, arcA, and arcB), and other relevant genes (luxS, sodA, fumA, and sdhB). Transcriptional changes explained the observed alterations in overall stoichiometric and kinetic parameters, and production of ethanol and organic acids. Differences in transcription levels between aerobic and anaerobic compartments were also observed, indicating that E. coli can respond very fast to intermittent DOT conditions. The transcriptional responses of E. coli to DOT gradients reported here are useful for establishing rational scale-up criteria and strain design strategies for improved culture performance at large scales. (c) 2005 Wiley Periodicals, Inc.

Physical Activity Promotion on Campus: Using Empirical Evidence to Recommend Strategic Approaches to Target Female College Students

ERIC Educational Resources Information Center

Milroy, Jeffrey J.; Orsini, Muhsin Michael; D'Abundo, Michelle Lee; Sidman, Cara Lynn; Venezia, Diana

2015-01-01

Problem: A large number of American adults do not meet national physical activity (PA) guidelines for aerobic PA and muscle strengthening. Similarly, many American college students, specifically females do not engage in regular PA. Self Determination Theory can provide a basis for investigating motivational processes of PA. The purpose of this…

Sequential anaerobic-aerobic biological treatment of colored wastewaters: case study of a textile dyeing factory wastewater.

PubMed

Abiri, Fardin; Fallah, Narges; Bonakdarpour, Babak

2017-03-01

In the present study the feasibility of the use of a bacterial batch sequential anaerobic-aerobic process, in which activated sludge was used in both parts of the process, for pretreatment of wastewater generated by a textile dyeing factory has been considered. Activated sludge used in the process was obtained from a municipal wastewater treatment plant and adapted to real dyeing wastewater using either an anaerobic-only or an anaerobic-aerobic process over a period of 90 days. The use of activated sludge adapted using the anaerobic-aerobic process resulted in a higher overall decolorization efficiency compared to that achieved with activated sludge adapted using the anaerobic-only cycles. Anaerobic and aerobic periods of around 34 and 22 hours respectively resulted in an effluent with chemical oxygen demand (COD) and color content which met the standards for discharge into the centralized wastewater treatment plant of the industrial estate in which the dyeing factory was situated. Neutralization of the real dyeing wastewater and addition of carbon source to it, both of which results in significant increase in the cost of the bacterial treatment process, was not found to be necessary to achieve the required discharge standards.

Performance Evaluation of Existing Wedgewater and Vacuum-Assisted Bed Dewatering Systems

DTIC Science & Technology

1992-01-01

prior to dewatering by the wedgewater method. Of the 20 satisfied users, 11 preferred aerobic digestion , two employed anaerobic digestion, and seven...did not further process their sludge. Of the seven dissatisfied users, four used aerobic digestion and three employed anaerobic digestion. A meelic...queried, 11 employed aerobic digestion , two employed anaerobic digestion, and three did not process their sludge. Eight dissatisfied users employed

Filamentous bacteria existence in aerobic granular reactors.

PubMed

Figueroa, M; Val del Río, A; Campos, J L; Méndez, R; Mosquera-Corral, A

2015-05-01

Filamentous bacteria are associated to biomass settling problems in wastewater treatment plants. In systems based on aerobic granular biomass they have been proposed to contribute to the initial biomass aggregation process. However, their development on mature aerobic granular systems has not been sufficiently studied. In the present research work, filamentous bacteria were studied for the first time after long-term operation (up to 300 days) of aerobic granular systems. Chloroflexi and Sphaerotilus natans have been observed in a reactor fed with synthetic wastewater. These filamentous bacteria could only come from the inoculated sludge. Thiothrix and Chloroflexi bacteria were observed in aerobic granular biomass treating wastewater from a fish canning industry. Meganema perideroedes was detected in a reactor treating wastewater from a plant processing marine products. As a conclusion, the source of filamentous bacteria in these mature aerobic granular systems fed with industrial effluents was the incoming wastewater.

Theoretical investigation of aerobic and anaerobic oxidative inactivation of the [NiFe]-hydrogenase active site.

PubMed

Breglia, Raffaella; Greco, Claudio; Fantucci, Piercarlo; De Gioia, Luca; Bruschi, Maurizio

2018-01-17

The extraordinary capability of [NiFe]-hydrogenases to catalyse the reversible interconversion of protons and electrons into dihydrogen (H 2 ) has stimulated numerous experimental and theoretical studies addressing the direct utilization of these enzymes in H 2 production processes. Unfortunately, the introduction of these natural H 2 -catalysts in biotechnological applications is limited by their inhibition under oxidising (aerobic and anaerobic) conditions. With the aim of contributing to overcome this limitation, we studied the oxidative inactivation mechanism of [NiFe]-hydrogenases by performing Density Functional Theory (DFT) calculations on a very large model of their active site in which all the amino acids forming the first and second coordination spheres of the NiFe cluster have been explicitly included. We identified an O 2 molecule and two H 2 O molecules as sources of the two oxygen atoms that are inserted at the active site of the inactive forms of the enzyme (Ni-A and Ni-B) under aerobic and anaerobic conditions, respectively. Furthermore, our results support the experimental evidence that the Ni-A-to-Ni-B ratio strongly depends on the number of reducing equivalents available for the process and on the oxidizing conditions under which the reaction takes place.

Treatment of HMX-production wastewater in an aerobic granular reactor.

PubMed

Zhang, Jin-Hua; Wang, Min-Hui; Zhu, Xiao-Meng

2013-04-01

Aerobic granules were applied to the treatment of HMX-production wastewater using a gradual domestication method in a SBR. During the process, the granules showed a good settling ability, a high biomass retention rate, and high biological activity. After 40 days of stable operation, aerobic granular sludge performed very effectively in the removal of carbon and nitrogen compounds from HMX-production wastewater. Organic matter removal rates up to 97.57% and nitrogen removal efficiencies up to 80% were achieved during the process. Researchers conclude that using aerobic granules to treat explosive wastewater has good prospects for success.

Characteristics of greenhouse gas emission in three full-scale wastewater treatment processes.

PubMed

Yan, Xu; Li, Lin; Liu, Junxin

2014-02-01

Three full-scale wastewater treatment processes, Orbal oxidation ditch, anoxic/anaerobic/aerobic (reversed A2O) and anaerobic/anoxic/aerobic (A2O), were selected to investigate the emission characteristics of greenhouse gases (GHG), including carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Results showed that although the processes were different, the units presenting high GHG emission fluxes were remarkably similar, namely the highest CO2 and N2O emission fluxes occurred in the aerobic areas, and the highest CH4 emission fluxes occurred in the grit tanks. The GHG emission amount of each unit can be calculated from its area and GHG emission flux. The calculation results revealed that the maximum emission amounts of CO2, CH4 and N2O in the three wastewater treatment processes appeared in the aerobic areas in all cases. Theoretically, CH4 should be produced in anaerobic conditions, rather than aerobic conditions. However, results in this study showed that the CH4 emission fluxes in the forepart of the aerobic area were distinctly higher than in the anaerobic area. The situation for N2O was similar to that of CH4: the N2O emission flux in the aerobic area was also higher than that in the anoxic area. Through analysis of the GHG mass balance, it was found that the flow of dissolved GHG in the wastewater treatment processes and aerators may be the main reason for this phenomenon. Based on the monitoring and calculation results, GHG emission factors for the three wastewater treatment processes were determined. The A2O process had the highest CO2 emission factor of 319.3 g CO2/kg COD(removed), and the highest CH4 and N2O emission factors of 3.3 g CH4/kg COD(removed) and 3.6 g N2O/kg TN(removed) were observed in the Orbal oxidation ditch process.

Enhanced nitrogen removal from electroplating tail wastewater through two-staged anoxic-oxic (A/O) process.

PubMed

Yan, Xinmei; Zhu, Chunyan; Huang, Bin; Yan, Qun; Zhang, Guangsheng

2018-01-01

Consisted of anaerobic (ANA), anoxic-1 (AN1), aerobic-1 (AE1), anoxic-2 (AN2), aerobic-2 (AE2) reactors and sediment tank, the two-staged A/O process was applied for depth treatment of electroplating tail wastewater with high electrical conductivity and large amounts of ammonia nitrogen. It was found that the NH 4 + -N and COD removal efficiencies reached 97.11% and 83.00%, respectively. Besides, the short-term salinity shock of the control, AE1 and AE2 indicated that AE1 and AE2 have better resistance to high salinity when the concentration of NaCl ranged from 1 to 10g/L. Meanwhile, it was found through high-throughput sequencing that bacteria genus Nitrosomonas, Nitrospira and Thauera, which are capable of nitrogen removal, were enriched in the two-staged A/O process. Moreover, both salt-tolerant bacteria and halophili bacteria were also found in the combined process. Therefore, microbial community within the two-staged A/O process could be acclimated to high electrical conductivity, and adapted for electroplating tail wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biochemical Process Development and Integration | Bioenergy | NREL

Science.gov Websites

Process Development We develop and scale fermentation processes that produce fuels and chemicals from guide experimental designs. Our newly updated fermentation laboratory houses 38 bench-scale fermentors current projects cover the fermentation spectrum including anaerobic, micro-aerobic, aerobic, and gas-to

Energy Conservation at the West Dover, Vermont, Water Pollution Control Facility.

DTIC Science & Technology

1982-11-01

chlorination of oxidation ditch effluent ---- 8 Discontinue aerobic digestion --------------------------- 8 Discharge contents of holding pond into...Immediate Discontinue aerobic digestion Instead of aerobically digesting the waste activated sludge, it may be possible to mix it directly with pond...elimi- nated by replacing the oxidation ditches with facultative ponds. Also, this would eliminate the need for aerobic digestion , in-plant process water

The study of a pilot-scale aerobic/Fenton/anoxic/aerobic process system for the treatment of landfill leachate.

PubMed

Hu, Wenyong; Zhou, Yu; Min, Xiaobo; Liu, Jingyi; Li, Xinyu; Luo, Lin; Zhang, Jiachao; Mao, Qiming; Chai, Liyuan; Zhou, YaoYu

2017-06-29

In this study, a combined aerobic-Fenton-anoxic/aerobic system was designed for the remediation of raw landfill leachate in a pilot-scale experiment. This system included (i) a granular sludge biological oxidation procedure that achieves the accumulation of nitrite nitrogen ([Formula: see text]) under aerobic conditions; (ii) a Fenton process that improves the biodegradability of the biotreated leachate and (iii) an activated sludge biological oxidation component under anoxic and aerobic conditions. Additionally, a shortcut nitrification and denitrification pathway was achieved. The effects of free ammonia, temperature and pH on nitrite accumulation were discussed. The change in the biochemical oxygen demand/chemical oxygen demand ratio of the effluent after shortcut nitrification was also analysed. The microbial community in the reactor were also investigated. The problem of the lack of carbon source in the denitrification process can be solved by the Fenton reagent method. Moreover, it was beneficial to achieving nitrogen removal as well as the more extensive removal of organic matter. The treatment strategy employed in this study exhibited good results and provided the potential practical application for treating landfill leachate.

The impact of nanoparticles on aerobic degradation of municipal solid waste.

PubMed

Yazici Guvenc, Senem; Alan, Burcu; Adar, Elanur; Bilgili, Mehmet Sinan

2017-04-01

The amount of nanoparticles released from industrial and consumer products has increased rapidly in the last decade. These products may enter landfills directly or indirectly after the end of their useful life. In order to determine the impact of TiO 2 and Ag nanoparticles on aerobic landfilling processes, municipal solid waste was loaded to three pilot-scale aerobic landfill bioreactors (80 cm diameter and 350 cm height) and exposed to TiO 2 (AT) and Ag (AA) nanoparticles at total concentrations of 100 mg kg -1 of solid waste. Aerobic landfill bioreactors were operated under the conditions about 0.03 L min -1 kg -1 aeration rate for 250 days, during which the leachate, solid waste, and gas characteristics were measured. The results indicate that there was no significant difference in the leachate characteristics, gas constituents, solid quality parameters, and temperature variations, which are the most important indicators of landfill operations, and overall aerobic degradation performance between the reactors containing TiO 2 and Ag nanoparticles, and control (AC) reactor. The data also indicate that the pH levels, ionic strength, and the complex formation capacity of nanoparticles with Cl - ions can reduce the toxicity effects of nanoparticles on aerobic degradation processes. The results suggest that TiO 2 and Ag nanoparticles at concentrations of 100 mg kg -1 of solid waste do not have significant impacts on aerobic biological processes and waste management systems.

Carbon, nitrogen and phosphorus removal mechanisms of aerobic granules.

PubMed

Sarma, Saurabh Jyoti; Tay, Joo-Hwa

2018-04-10

Aerobic granules are the potential tools to develop modern wastewater treatment technologies with improved nutrient removal efficiency. These granules have several promising advantages over conventional activated sludge-based wastewater treatment processes. This technology has the potential of reducing the infrastructure and operation costs of wastewater treatment by 25%, energy requirement by 30%, and space requirement by 75%. The nutrient removal mechanisms of aerobic granules are slightly different from that of the activated sludge. For instance, unlike activated sludge process, according to some reports, as high as 70% of the total phosphorus removed by aerobic granules were attributed to precipitation within the granules. Similarly, aerobic granule-based technology reduces the total amount of sludge produced during wastewater treatment. However, the reason behind this observation is unknown and it needs further explanations based on carbon and nitrogen removal mechanisms. Thus, as a part of the present review, a set of new hypotheses have been proposed to explain the peculiar nutrient removal mechanisms of the aerobic granules.

Microbial transformation of pharmaceuticals naproxen, bisoprolol, and diclofenac in aerobic and anaerobic environments.

PubMed

Lahti, Marja; Oikari, Aimo

2011-08-01

Although biotransformation is generally considered to be the main process by which to remove pharmaceuticals, both in sewage treatment plants and in aquatic environments, quantitative information on specific compounds is scarce. In this study, the transformations of diclofenac (DCF), naproxen (NPX), and bisoprolol (BSP) were studied under aerobic and anaerobic conditions using inocula taken from activated and digested sludge processes, respectively. Whereas concentration decays were monitored by LC-tandem mass spectrometry, oxygen consumption and methane production were used for the evaluation of the performance of overall conditions. DCF was recalcitrant against both aerobic and anaerobic biotransformation. More than one third of the BSP disappeared under aerobic conditions, whereas only 14% was anaerobically biotransformed in 161 days. Under aerobic conditions, complete removal of NPX was evident within 14 days, but anaerobic transformation was also efficient. Formation of 6-O-desmethylnaproxen, a previously reported aerobic metabolite, was also detected under anaerobic conditions and persisted for 161 days.

Combined thermophilic aerobic process and conventional anaerobic digestion: effect on sludge biodegradation and methane production.

PubMed

Dumas, C; Perez, S; Paul, E; Lefebvre, X

2010-04-01

The efficiency of hyper-thermophilic (65 degrees Celsius) aerobic process coupled with a mesophilic (35 degrees Celsius) digester was evaluated for the activated sludge degradation and was compared to a conventional mesophilic digester. For two Sludge Retention Time (SRT), 21 and 42 days, the Chemical Oxygen Demand (COD) solubilisation and biodegradation processes, the methanisation yield and the aerobic oxidation were investigated during 180 days. The best results were obtained at SRT of 44 days; the COD removal yield was 30% higher with the Mesophilic Anaerobic Digestion/Thermophilic Aerobic Reactor (MAD-TAR) co-treatment. An increase of the sludge intrinsic biodegradability is also observed (20-40%), showing that the unbiodegradable COD in mesophilic conditions becomes bioavailable. However, the methanisation yield was quite similar for both processes at a same SRT. Finally, such a process enables to divide by two the volume of digester with an equivalent efficiency. Copyright 2009 Elsevier Ltd. All rights reserved.

Bio-drying of municipal solid waste with high water content by aeration procedures regulation and inoculation.

PubMed

Zhang, Dong-Qing; He, Pin-Jing; Jin, Tai-Feng; Shao, Li-Ming

2008-12-01

To improve the water content reduction of municipal solid waste with high water content, the operations of supplementing a hydrolytic stage prior to aerobic degradation and inoculating the bio-drying products were conducted. A 'bio-drying index' was used to evaluate the bio-drying performance. For the aerobic processes, the inoculation accelerated organics degradation, enhanced the lignocelluloses degradation rate by 10.4%, and lowered water content by 7.0%. For the combined hydrolytic-aerobic processes, the inoculum addition had almost no positive effect on the bio-drying efficiency, but it enhanced the lignocelluloses degradation rate by 9.6% and strengthened the acidogenesis in the hydrolytic stage. Compared with the aerobic processes, the combined processes had a higher bio-drying index (4.20 for non-inoculated and 3.67 for the inoculated trials). Moreover, the lowest final water content occurred in the combined process without inoculation (50.5% decreased from an initial 72.0%).

Tracking composition of microbial communities for simultaneous nitrification and denitrification in polyurethane foam.

PubMed

Chen, Yuan; Wang, Li; Ma, Fang; Yang, Ji-xian; Qiu, Shan

2014-01-01

The process of simultaneous nitrification and denitrification (SND) of immobilized microorganisms in polyurethane form is discussed. The effect of different positions within the polyurethane carrier on microbial community response for the SND process is investigated by a combination of denaturing gradient gel electrophoresis profiles of the 16S rRNA gene V3 region and scanning electron microscopy. Results show that polyurethane, which consists of a unique porous structure, is an ideal platform for biofilm stratification of aerobe, anaerobe and facultative microorganisms in regard to the SND process. The community structure diversity response to different positions was distinct. The distributions of various functional microbes, detected from the surface aerobic stratification to the interior anaerobic stratification of polyurethane, were mainly nitrifying and denitrifying bacteria. Meanwhile aerobic denitrifying bacteria such as Paracoccus sp., Agrobacterium rubi and Ochrobactrum sp. were also adhered to the interior and surface of polyurethane. The SND process occurring on polyurethane foam was carried out by two independent processes: nitrogen removal and aerobic denitrification.

Sequential anaerobic/aerobic digestion of waste activated sludge: analysis of the process performance and kinetic study.

PubMed

Tomei, M Concetta; Rita, Sara; Mininni, Giuseppe

2011-12-15

Sequential anaerobic-aerobic digestion was applied to waste activated sludge (WAS) of a full scale wastewater treatment plant. The study was performed with the objective of testing the sequential digestion process on WAS, which is characterized by worse digestibility in comparison with the mixed sludge. Process performance was evaluated in terms of biogas production, volatile solids (VS) and COD reduction, and patterns of biopolymers (proteins and polysaccharides) in the subsequent digestion stages. VS removal efficiency of 40%, in the anaerobic phase, and an additional removal of 26%, in the aerobic one, were observed. For total COD removal efficiencies of 35% and 25% for anaerobic and aerobic stage respectively, were obtained. Kinetics of VS degradation process was analyzed by assuming a first order equation with respect to VS concentration. Evaluated kinetic parameters were 0.44 ± 0.20 d(-1) and 0.25 ± 0.15 d(-1) for the anaerobic stage and aerobic stage, respectively. With regard to biopolymers, in the anaerobic phase the content of proteins and polysaccharides increased to 50% and 69%, respectively, whereas in the subsequent aerobic phase, a decrease of 71% for proteins and 67% for polysaccharides was observed. The average specific biogas production 0.74 m(3)/(kg VS destroyed), was in the range of values reported in the specialized literature for conventional anaerobic mesophilic WAS digestion. Copyright © 2011 Elsevier B.V. All rights reserved.

Kinetics of aerobic cometabolic biodegradation of chlorinated and brominated aliphatic hydrocarbons: A review.

PubMed

Jesus, João; Frascari, Dario; Pozdniakova, Tatiana; Danko, Anthony S

2016-05-15

This review analyses kinetic studies of aerobic cometabolism (AC) of halogenated aliphatic hydrocarbons (HAHs) from 2001-2015 in order to (i) compare the different kinetic models proposed, (ii) analyse the estimated model parameters with a focus on novel HAHs and the identification of general trends, and (iii) identify further research needs. The results of this analysis show that aerobic cometabolism can degrade a wide range of HAHs, including HAHs that were not previously tested such as chlorinated propanes, highly chlorinated ethanes and brominated methanes and ethanes. The degree of chlorine mineralization was very high for the chlorinated HAHs. Bromine mineralization was not determined for studies with brominated aliphatics. The examined research period led to the identification of novel growth substrates of potentially high interest. Decreasing performance of aerobic cometabolism were found with increasing chlorination, indicating the high potential of aerobic cometabolism in the presence of medium- and low-halogenated HAHs. Further research is needed for the AC of brominated aliphatic hydrocarbons, the potential for biofilm aerobic cometabolism processes, HAH-HAH mutual inhibition and the identification of the enzymes responsible for each aerobic cometabolism process. Lastly, some indications for a possible standardization of future kinetic studies of HAH aerobic cometabolism are provided. Copyright © 2016 Elsevier B.V. All rights reserved.

Aerobic Digestion. Biological Treatment Process Control. Instructor's Guide.

ERIC Educational Resources Information Center

Klopping, Paul H.

This unit on aerobic sludge digestion covers the theory of the process, system components, factors that affect the process performance, standard operational concerns, indicators of steady-state operations, and operational problems. The instructor's guide includes: (1) an overview of the unit; (2) lesson plan; (3) lecture outline (keyed to a set of…

Simulation of aerobic and anaerobic biodegradation processes at a crude oil spill site

USGS Publications Warehouse

Essaid, Hedeff I.; Bekins, Barbara A.; Godsy, E. Michael; Warren, Ean; Baedecker, Mary Jo; Cozzarelli, Isabelle M.

1995-01-01

A two-dimensional, multispecies reactive solute transport model with sequential aerobic and anaerobic degradation processes was developed and tested. The model was used to study the field-scale solute transport and degradation processes at the Bemidji, Minnesota, crude oil spill site. The simulations included the biodegradation of volatile and nonvolatile fractions of dissolved organic carbon by aerobic processes, manganese and iron reduction, and methanogenesis. Model parameter estimates were constrained by published Monod kinetic parameters, theoretical yield estimates, and field biomass measurements. Despite the considerable uncertainty in the model parameter estimates, results of simulations reproduced the general features of the observed groundwater plume and the measured bacterial concentrations. In the simulation, 46% of the total dissolved organic carbon (TDOC) introduced into the aquifer was degraded. Aerobic degradation accounted for 40% of the TDOC degraded. Anaerobic processes accounted for the remaining 60% of degradation of TDOC: 5% by Mn reduction, 19% by Fe reduction, and 36% by methanogenesis. Thus anaerobic processes account for more than half of the removal of DOC at this site.

Aerobic Digestion. Student Manual. Biological Treatment Process Control.

ERIC Educational Resources Information Center

Klopping, Paul H.

This manual contains the textual material for a single-lesson unit on aerobic sludge digestion. Topic areas addressed include: (1) theory of aerobic digestion; (2) system components; (3) performance factors; (4) indicators of stable operation; and (5) operational problems and their solutions. A list of objectives, glossary of key terms, and…

Scaling with body mass of mitochondrial respiration from the white muscle of three phylogenetically, morphologically and behaviorally disparate teleost fishes.

PubMed

Burpee, Jessica L; Bardsley, Elise L; Dillaman, Richard M; Watanabe, Wade O; Kinsey, Stephen T

2010-10-01

White muscle (WM) fibers in many fishes often increase in size from <50 μm in juveniles to >250 μm in adults. This leads to increases in intracellular diffusion distances that may impact the scaling with body mass of muscle metabolism. We have previously found similar negative scaling of aerobic capacity (mitochondrial volume density, V(mt)) and the rate of an aerobic process (post-contractile phosphocreatine recovery) in fish WM. In the present study, we examined the scaling with body mass of oxygen consumption rates of isolated mitochondria (VO(2mt)) from WM in three species from different families that vary in morphology and behavior: an active, pelagic species (bluefish, Pomatomus saltatrix), a relatively inactive demersal species (black sea bass, Centropristis striata), and a sedentary, benthic species (southern flounder, Paralichthys lethostigma). In contrast to our prior studies, the measurement of respiration in isolated mitochondria is not influenced by the diffusion of oxygen or metabolites. V(mt) was measured in WM and in high-density isolates used for VO(2mt) measurements. WM V(mt) was significantly higher in the bluefish than in the other two species and VO(2mt) was independent of body mass when expressed per milligram protein or per milliliter mitochondria. The size-independence of VO(2mt) indicates that differences in WM aerobic function result from variation in V(mt) and not to changes in VO(2mt). This is consistent with our prior work that indicated that while diffusion constraints influence mitochondrial distribution, the negative scaling of aerobic processes like post-contractile PCr recovery can largely be attributed to the body size dependence of V(mt).

Survival rates of parasite eggs in sludge during aerobic and anaerobic digestion.

PubMed Central

Black, M I; Scarpino, P V; O'Donnell, C J; Meyer, K B; Jones, J V; Kaneshiro, E S

1982-01-01

The effects of mesothermic anaerobic or aerobic sludge digestion on survival of eggs from the roundworms Ascaris suum, toxocara canis, Trichuris vulpis, and Trichuris suis and from the rat tapeworm Hymenolepis diminuta were studied. Destruction of eggs throughout a 15-day treatment period, as well as their viabilities after reisolation, was analyzed. The laboratory model digesters used in this study were maintained at a 15-day retention schedule, partially simulating a continuously operating system. Ascaris eggs were destroyed in the anaerobic (23%) or aerobic (38%) digesters, and 11% Trichuris eggs were destroyed in the aerobic digesters. Trichuris eggs in anaerobic digesters and Toxocara eggs in either anaerobic or aerobic digesters were not destroyed. Destruction of eggs in digesters was correlated with the state of the eggs before subjection to the treatment processes; i.e., some Ascaris and Trichuris eggs were already embryonated in host intestinal contents or feces and hence past their most resistant stage. The viabilities of Ascaris and Toxocara eggs that survived the digestion processes were greater in anaerobically treated than in aerobically treated material. Eggs from Hymenolepis were nonviable before use in the experiments. However, they were more effectively destroyed in aerobic digesters than in anaerobic digesters. PMID:6891199

Degradation of organophosphate esters in sewage sludge: Effects of aerobic/anaerobic treatments and bacterial community compositions.

PubMed

Pang, Long; Ge, Liming; Yang, Peijie; He, Han; Zhang, Hongzhong

2018-05-01

In this study, the degradation of organophosphate esters (OPEs) in sewage sludge with aerobic composting and anaerobic digestion was investigated. The total concentrations of six OPEs (ΣOPEs) in the whole treatment process reduced in the order of anaerobic digestion combined with pig manure (T3) > aerobic composting combined with pig manure (T1) > aerobic composting (T2) > anaerobic digestion (T4). The addition of pig manure significantly enhanced the removal rate of OPEs in both aerobic and anaerobic treatments. The abundance and diversity of bacterial community reduced after the treatment process. Shannon index, principal component analysis, network analysis, and heat map further confirmed the variation of bacterial community compositions among different treatments. Five genera (i.e., Flavobacterium, Bacillus, Alcaligene, Pseudomonas, and Bacillus megaterium) might be responsible for the degradation of OPE compounds in sewage sludge. Copyright © 2018 Elsevier Ltd. All rights reserved.

The 'aerobic/resistance/inspiratory muscle training hypothesis in heart failure'.

PubMed

Laoutaris, Ioannis D

2018-01-01

Evidence from large multicentre exercise intervention trials in heart failure patients, investigating both moderate continuous aerobic training and high intensity interval training, indicates that the 'crème de la crème' exercise programme for this population remains to be found. The 'aerobic/resistance/inspiratory (ARIS) muscle training hypothesis in heart failure' is introduced, suggesting that combined ARIS muscle training may result in maximal exercise pathophysiological and functional benefits in heart failure patients. The hypothesis is based on the decoding of the 'skeletal muscle hypothesis in heart failure' and on revision of experimental evidence to date showing that exercise and functional intolerance in heart failure patients are associated not only with reduced muscle endurance, indication for aerobic training (AT), but also with reduced muscle strength and decreased inspiratory muscle function contributing to weakness, dyspnoea, fatigue and low aerobic capacity, forming the grounds for the addition of both resistance training (RT) and inspiratory muscle training (IMT) to AT. The hypothesis will be tested by comparing all potential exercise combinations, ARIS, AT/RT, AT/IMT, AT, evaluating both functional and cardiac indices in a large sample of heart failure patients of New York Heart Association class II-III and left ventricular ejection fraction ≤35% ad hoc by the multicentre randomized clinical trial, Aerobic Resistance, InSpiratory Training OutcomeS in Heart Failure (ARISTOS-HF trial).

Could petroleum biodegradation be a joint achievement of aerobic and anaerobic microrganisms in deep sea reservoirs?

PubMed Central

2011-01-01

Several studies suggest that petroleum biodegradation can be achieved by either aerobic or anaerobic microorganisms, depending on oxygen input or other electron acceptors and appropriate nutrients. Evidence from in vitro experiments with samples of petroleum formation water and oils from Pampo Field indicate that petroleum biodegradation is more likely to be a joint achievement of both aerobic and anaerobic bacterial consortium, refining our previous observations of aerobic degradation. The aerobic consortium depleted, in decreasing order, hydrocarbons > hopanes > steranes > tricyclic terpanes while the anaerobic consortium depleted hydrocarbons > steranes > hopanes > tricyclic terpanes. The oxygen content of the mixed consortia was measured from time to time revealing alternating periods of microaerobicity (O2 ~0.8 mg.L-1) and of aerobicity (O2~6.0 mg.L-1). In this experiment, the petroleum biodegradation changed from time to time, alternating periods of biodegradation similar to the aerobic process and periods of biodegradation similar to the anaerobic process. The consortia showed preferences for metabolizing hydrocarbons > hopanes > steranes > tricyclic terpanes during a 90-day period, after which this trend changed and steranes were more biodegraded than hopanes. The analysis of aerobic oil degrading microbiota by the 16S rRNA gene clone library detected the presence of Bacillus, Brevibacterium, Mesorhizobium and Achromobacter, and the analysis of the anaerobic oil degrading microbiota using the same technique detected the presence of Bacillus and Acinetobacter (facultative strains). In the mixed consortia Stenotrophomonas, Brevibacterium, Bacillus, Rhizobium, Achromobacter and 5% uncultured bacteria were detected. This is certainly a new contribution to the study of reservoir biodegradation processes, combining two of the more important accepted hypotheses. PMID:22196374

Anaerobic Metabolism: Linkages to Trace Gases and Aerobic Processes

NASA Astrophysics Data System (ADS)

Megonigal, J. P.; Hines, M. E.; Visscher, P. T.

2003-12-01

Life evolved and flourished in the absence of molecular oxygen (O2). As the O2 content of the atmosphere rose to the present level of 21% beginning about two billion years ago, anaerobic metabolism was gradually supplanted by aerobic metabolism. Anaerobic environments have persisted on Earth despite the transformation to an oxidized state because of the combined influence of water and organic matter. Molecular oxygen diffuses about 104 times more slowly through water than air, and organic matter supports a large biotic O2 demand that consumes the supply faster than it is replaced by diffusion. Such conditions exist in wetlands, rivers, estuaries, coastal marine sediments, aquifers, anoxic water columns, sewage digesters, landfills, the intestinal tracts of animals, and the rumen of herbivores. Anaerobic microsites are also embedded in oxic environments such as upland soils and marine water columns. Appreciable rates of aerobic respiration are restricted to areas that are in direct contact with air or those inhabited by organisms that produce O2.Rising atmospheric O2 reduced the global area of anaerobic habitat, but enhanced the overall rate of anaerobic metabolism (at least on an area basis) by increasing the supply of electron donors and acceptors. Organic carbon production increased dramatically, as did oxidized forms of nitrogen, manganese, iron, sulfur, and many other elements. In contemporary anaerobic ecosystems, nearly all of the reducing power is derived from photosynthesis, and most of it eventually returns to O2, the most electronegative electron acceptor that is abundant. This photosynthetically driven redox gradient has been thoroughly exploited by aerobic and anaerobic microorganisms for metabolism. The same is true of hydrothermal vents (Tunnicliffe, 1992) and some deep subsurface environments ( Chapelle et al., 2002), where thermal energy is the ultimate source of the reducing power.Although anaerobic habitats are currently a small fraction of Earth's surface area, they have a profound influence on the biogeochemistry of the planet. This is evident from the observation that the O2 and CH4 content of Earth's atmosphere are in extreme disequilibrium (Sagan et al., 1993). The combination of high aerobic primary production and anoxic sediments provided the large deposits of fossil fuels that have become vital and contentious sources of energy for modern industrialized societies. Anaerobic metabolism is responsible for the abundance of N2 in the atmosphere; otherwise N2-fixing bacteria would have consumed most of the N2 pool long ago (Schlesinger, 1997). Anaerobic microorganisms are common symbionts of termites, cattle, and many other animals, where they aid digestion. Nutrient and pollutant chemistry are strongly modified by the reduced conditions that prevail in wetland and aquatic ecosystems.This review of anaerobic metabolism emphasizes aerobic oxidation, because the two processes cannot be separated in a complete treatment of the topic. It is process oriented and highlights the fascinating microorganisms that mediate anaerobic biogeochemistry. We begin this review with a brief discussion of CO2 assimilation by autotrophs, the source of most of the reducing power on Earth, and then consider the biological processes that harness this potential energy. Energy liberation begins with the decomposition of organic macromolecules to relatively simple compounds, which are simplified further by fermentation. Methanogenesis is considered next because CH4 is a product of acetate fermentation, and thus completes the catabolism of organic matter, particularly in the absence of inorganic electron acceptors. Finally, the organisms that use nitrogen, manganese, iron, and sulfur for terminal electron acceptors are considered in order of decreasing free-energy yield of the reactions.

The Study of Cognitive Change Process on Depression during Aerobic Exercises.

PubMed

Sadeghi, Kheirollah; Ahmadi, Seyed Mojtaba; Moghadam, Arash Parsa; Parvizifard, Aliakbar

2017-04-01

Several studies have shown that aerobic exercise is effective in treating the depression and improving the mental health. There are various theories which explains why aerobic exercise is effective in the treatment of depression and improve mental health, but there are limited studies to show how cognitive components and depression improve during aerobic exercises. The current study was carried out to investigate the cognitive change process during aerobic exercises in depressed students. This study was conducted through structural equation modeling; the study sample included 85 depressed students. Participants were selected through purposive sampling method. Beck Depression Inventory (BDI-II), Automatic Negative Thoughts (ATQ), and the Dysfunctional Attitude Scale (DAS) were used as the data collection instruments. The participants received eight sessions of aerobic exercise (three times a week). The obtained data was analysed by AMOS-18 & SPSS 18 software. The results showed that depression (p=0.001), automatic thoughts (ferquency p=0.413, beliefs p=0.676) and dysfunctional assumptions (p=0.219) reduce during aerobic exercise; however, it was only meaningful for the depression. The casual and consequential models were not fit to the data and partially and fully interactive models provided an adequate fit to the data. Fully interactive model provided the best fit of the data. It seems that aerobic exercise reduced cognitive components separately leading to reduce depression.

Aerobic Exercise During Encoding Impairs Hippocampus-Dependent Memory.

PubMed

Soga, Keishi; Kamijo, Keita; Masaki, Hiroaki

2017-08-01

We investigated how aerobic exercise during encoding affects hippocampus-dependent memory through a source memory task that assessed hippocampus-independent familiarity and hippocampus-dependent recollection processes. Using a within-participants design, young adult participants performed a memory-encoding task while performing a cycling exercise or being seated. The subsequent retrieval phase was conducted while sitting on a chair. We assessed behavioral and event-related brain potential measures of familiarity and recollection processes during the retrieval phase. Results indicated that source accuracy was lower for encoding with exercise than for encoding in the resting condition. Event-related brain potential measures indicated that the parietal old/new effect, which has been linked to recollection processing, was observed in the exercise condition, whereas it was absent in the rest condition, which is indicative of exercise-induced hippocampal activation. These findings suggest that aerobic exercise during encoding impairs hippocampus-dependent memory, which may be attributed to inefficient source encoding during aerobic exercise.

The Association between Aerobic Fitness and Language Processing in Children: Implications for Academic Achievement

PubMed Central

Scudder, Mark R.; Federmeier, Kara D.; Raine, Lauren B.; Direito, Artur; Boyd, Jeremy K.; Hillman, Charles H.

2014-01-01

Event-related brain potentials (ERPs) have been instrumental for discerning the relationship between children’s aerobic fitness and aspects of cognition, yet language processing remains unexplored. ERPs linked to the processing of semantic information (the N400) and the analysis of language structure (the P600) were recorded from higher and lower aerobically fit children as they read normal sentences and those containing semantic or syntactic violations. Results revealed that higher fit children exhibited greater N400 amplitude and shorter latency across all sentence types, and a larger P600 effect for syntactic violations. Such findings suggest that higher fitness may be associated with a richer network of words and their meanings, and a greater ability to detect and/or repair syntactic errors. The current findings extend previous ERP research explicating the cognitive benefits associated with greater aerobic fitness in children and may have important implications for learning and academic performance. PMID:24747513

Enhanced performance of denitrifying sulfide removal process under micro-aerobic condition.

PubMed

Chen, Chuan; Ren, Nanqi; Wang, Aijie; Liu, Lihong; Lee, Duu-Jong

2010-07-15

The denitrifying sulfide removal (DSR) process with bio-granules comprising both heterotrophic and autotrophic denitrifiers can simultaneously convert nitrate, sulfide and acetate into di-nitrogen gas, elementary sulfur and carbon dioxide, respectively, at high loading rates. This study determines the reaction rate of sulfide oxidized into sulfur, as well as the reduction of nitrate to nitrite, would be enhanced under a micro-aerobic condition. The presence of limited oxygen mitigated the inhibition effects of sulfide on denitrifier activities, and enhanced the performance of DSR granules. The advantages and disadvantages of applying the micro-aerobic condition to the DSR process are discussed. 2010 Elsevier B.V. All rights reserved.

Effects of exercise on functional aerobic capacity in adults with fibromyalgia syndrome: A systematic review of randomized controlled trials.

PubMed

García-Hermoso, Antonio; Saavedra, Jose M; Escalante, Yolanda

2015-01-01

Patients with fibromyalgia present a reduced capacity of upper and lower limb physical performance and affect their independence in performing everyday activities. The purpose of the present systematic review was to summarize evidence for the effectiveness and structure of exercise programs on functional aerobic capacity in patients with fibromyalgia syndrome. Keyword searches were made of seven databases. The systematic review was limited to English language studies of people with FM that evaluated the effects of exercise programs on functional aerobic capacity (6-minute walk test). The criteria for inclusion were satisfied by 12 randomized controlled trial (RCT) studies. The main cumulative evidence indicates that the programs based on aerobic exercise alone and on aquatic exercises have large (effect size = 0.85) and moderate (effect size = 0.44) effects. Aerobic and aquatic exercises at the proper intensity favour the increased functional aerobic capacity of fibromyalgia patients; however, most works do not adequately detail the intensity of the exercises. Moderate intensity exercise (aerobic and aquatic exercise) performed at least two times per week and 30-60 minutes a day is effective for increasing functional aerobic capacity, favouring the daily activities of daily living in this population.

Alternating anoxic feast/aerobic famine condition for improving granular sludge formation in sequencing batch airlift reactor at reduced aeration rate.

PubMed

Wan, Junfeng; Bessière, Yolaine; Spérandio, Mathieu

2009-12-01

In this study the influence of a pre-anoxic feast period on granular sludge formation in a sequencing batch airlift reactor is evaluated. Whereas a purely aerobic SBR was operated as a reference (reactor R2), another reactor (R1) was run with a reduced aeration rate and an alternating anoxic-aerobic cycle reinforced by nitrate feeding. The presence of pre-anoxic phase clearly improved the densification of aggregates and allowed granular sludge formation at reduced air flow rate (superficial air velocity (SAV)=0.63cms(-1)). A low sludge volume index (SVI(30)=45mLg(-1)) and a high MLSS concentration (9-10gL(-1)) were obtained in the anoxic/aerobic system compared to more conventional results for the aerobic reactor. A granular sludge was observed in the anoxic/aerobic system whilst only flocs were observed in the aerobic reference even when operated at a high aeration rate (SAV=2.83cms(-1)). Nitrification was maintained efficiently in the anoxic/aerobic system even when organic loading rate (OLR) was increased up to 2.8kgCODm(-3)d(-1). In the contrary nitrification was unstable in the aerobic system and dropped at high OLR due to competition between autotrophic and heterotrophic growth. The presence of a pre-anoxic period positively affected granulation process via different mechanisms: enhancing heterotrophic growth/storage deeper in the internal anoxic layer of granule, reducing the competition between autotrophic and heterotrophic growth. These processes help to develop dense granular sludge at a moderate aeration rate. This tends to confirm that oxygen transfer is the most limiting factor for granulation at reduced aeration. Hence the use of an alternative electron acceptor (nitrate or nitrite) should be encouraged during feast period for reducing energy demand of the granular sludge process.

Bio-methane from an-aerobic digestion using activated carbon adsorption.

PubMed

Farooq, Muhammad; Bell, Alexandra H; Almustapha, M N; Andresen, John M

2017-08-01

There is an increasing global demand for carbon-neutral bio-methane from an-aerobic digestion (AD) to be injected into national gas grids. Bio-gas, a methane -rich energy gas, is produced by microbial decomposition of organic matter through an-aerobic conditions where the presence of carbon dioxide and hydrogen sulphide affects its performance. Although the microbiological process in the AD can be tailored to enhance the bio-gas composition, physical treatment is needed to convert the bio-gas into bio-methane. Water washing is the most common method for upgrading bio-gas for bio-methane production, but its large use of water is challenging towards industrial scale-up. Hence, the present study focuses on scale-up comparison of water washing with activated-carbon adsorption using HYSYS and Aspen Process Economic Analyzer. The models show that for plants processing less than 500 m 3 /h water scrubbing was cost effective compared with activated carbon. However, against current fossil natural-gas cost of about 1 p/kWh in the UK both relied heavily on governmental subsidies to become economically feasible. For plants operating at 1000 m 3 /hr, the treatment costs were reduced to below 1.5 p/kWh for water scrubbing and 0.9 p/kWh for activated carbon where the main benefits of activated carbon were lower capital and operating costs and virtually no water losses. It is envisioned that this method can significantly aid the production of sustainable bio-methane. Copyright © 2017 Elsevier Ltd. All rights reserved.

Relating carbon and nitrogen isotope effects to reaction mechanisms during aerobic or anaerobic degradation of RDX (Hexahydro-1,3,5-Trinitro-1,3,5-Triazine) by pure bacterial cultures

USGS Publications Warehouse

Fuller, Mark E.; Heraty, Linnea J.; Condee, Charles W.; Vainberg, Simon; Sturchio, Neil C.; Böhlke, John Karl; Hatzinger, Paul B.

2016-01-01

Kinetic isotopic fractionation of carbon and nitrogen during RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) biodegradation was investigated with pure bacterial cultures under aerobic and anaerobic conditions. Relatively large bulk enrichments in 15N were observed during biodegradation of RDX via anaerobic ring cleavage (ε15N = −12.7‰ ± 0.8‰) and anaerobic nitro reduction (ε15N = −9.9‰ ± 0.7‰), in comparison to smaller effects during biodegradation via aerobic denitration (ε15N = −2.4‰ ± 0.2‰). 13C enrichment was negligible during aerobic RDX biodegradation (ε13C = −0.8‰ ± 0.5‰) but larger during anaerobic degradation (ε13C = −4.0‰ ± 0.8‰), with modest variability among genera. Dual-isotope ε13C/ε15N analyses indicated that the three biodegradation pathways could be distinguished isotopically from each other and from abiotic degradation mechanisms. Compared to the initial RDX bulk δ15N value of +9‰, δ15N values of the NO2− released from RDX ranged from −7‰ to +2‰ during aerobic biodegradation and from −42‰ to −24‰ during anaerobic biodegradation. Numerical reaction models indicated that N isotope effects of NO2− production were much larger than, but systematically related to, the bulk RDX N isotope effects with different bacteria. Apparent intrinsic ε15N-NO2− values were consistent with an initial denitration pathway in the aerobic experiments and more complex processes of NO2− formation associated with anaerobic ring cleavage. These results indicate the potential for isotopic analysis of residual RDX for the differentiation of degradation pathways and indicate that further efforts to examine the isotopic composition of potential RDX degradation products (e.g., NOx) in the environment are warranted.

Is back pain during childhood or adolescence associated with muscle strength, muscle endurance or aerobic capacity: three systematic literature reviews with one meta-analysis.

PubMed

Lardon, Arnaud; Leboeuf-Yde, Charlotte; Le Scanff, Christine

2015-01-01

Back pain is a common condition during childhood and adolescence. The causes of back pain are largely unknown but it seems plausible that some physical factors such as back muscle strength, back muscle endurance and aerobic capacity may play a role in its development, in particular in the early years. The objectives of this review were to investigate in childhood and adolescence 1) if muscular strength in trunk extension is associated with back pain, 2) if muscular endurance in trunk extension is associated with back pain and 3) if aerobic capacity is associated with back pain. Three systematic critical literature reviews with one meta-analysis. Systematic searches were made in June 2014 in PubMed, Embase and SportDiscus including longitudinal, retrospective or cross-sectional studies on back pain for subjects <20 years. Articles were accepted if they were written in French or English. The review process followed the AMSTAR recommendations. The possibility of conducting a meta-analysis was assessed for each research question. Four articles were included for the first objective, four for the second and three for the last. None of the included articles found an association between back muscle strength in extension and back pain. For the second objective, a protective association between back muscle endurance in extension and back pain was found, later confirmed in a meta-analysis (OR = 0.75, 95 % CI 0.58-0.98). The association between aerobic capacity and back pain is not clear. High back muscle endurance in extension appears protective of back pain in youngsters, but the roles of high back muscle strength in extension and aerobic capacity are less clear.

Food waste conversion options in Singapore: environmental impacts based on an LCA perspective.

PubMed

Khoo, Hsien H; Lim, Teik Z; Tan, Reginald B H

2010-02-15

Proper management and recycling of huge volumes of food waste is one of the challenges faced by Singapore. Semakau island - the only offshore landfill of the nation - only accepts inert, inorganic solid waste and therefore a large bulk of food waste is directed to incinerators. A remaining small percent is sent for recycling via anaerobic digestion (AD), followed by composting of the digestate material. This article investigates the environmental performance of four food waste conversion scenarios - based on a life cycle assessment perspective - taking into account air emissions, useful energy from the incinerators and AD process, as well as carbon dioxide mitigation from the compost products derived from the digestate material and a proposed aerobic composting system. The life cycle impact results were generated for global warming, acidification, eutrophication, photochemical oxidation and energy use. The total normalized results showed that a small-scale proposed aerobic composting system is more environmentally favorable than incinerators, but less ideal compared to the AD process. By making full use of the AD's Recycling Phase II process alone, the Singapore Green Plan's 2012 aim to increase the recycling of food waste to 30% can easily be achieved, along with reduced global warming impacts.

Effects of Exercise Modality During Additional "High-Intensity Interval Training" on Aerobic Fitness and Strength in Powerlifting and Strongman Athletes.

PubMed

Androulakis-Korakakis, Patroklos; Langdown, Louis; Lewis, Adam; Fisher, James P; Gentil, Paulo; Paoli, Antonio; Steele, James

2018-02-01

Androulakis-Korakakis, P, Langdown, L, Lewis, A, Fisher, JP, Gentil, P, Paoli, A, and Steele, J. Effects of exercise modality during additional "high-intensity interval training" on aerobic fitness and strength in powerlifting and strongman athletes. J Strength Cond Res 32(2): 450-457, 2018-Powerlifters and strongman athletes have a necessity for optimal levels of muscular strength while maintaining sufficient aerobic capacity to perform and recover between events. High-intensity interval training (HIIT) has been popularized for its efficacy in improving both aerobic fitness and strength but never assessed within the aforementioned population group. This study looked to compare the effect of exercise modality, e.g., a traditional aerobic mode (AM) and strength mode (SM), during HIIT on aerobic fitness and strength. Sixteen well resistance-trained male participants, currently competing in powerlifting and strongman events, completed 8 weeks of approximately effort- and volume-matched HIIT in 2 groups: AM (cycling, n = 8) and SM (resistance training, n = 8). Aerobic fitness was measured as predicted V[Combining Dot Above]O2max using the YMCA 3 minutes step test and strength as predicted 1 repetition maximum from a 4-6RM test using a leg extension. Both groups showed significant improvements in both strength and aerobic fitness. There was a significant between-group difference for aerobic fitness improvements favoring the AM group (p ≤ 0.05). There was no between-group difference for change in strength. Magnitude of change using within-group effect size for aerobic fitness and strength was considered large for each group (aerobic fitness, AM = 2.6, SM = 2.0; strength, AM = 1.9, SM = 1.9). In conclusion, our results support enhanced strength and aerobic fitness irrespective of exercise modality (e.g., traditional aerobic and resistance training). However, powerlifters and strongman athletes wishing to enhance their aerobic fitness should consider HIIT using an aerobic HIIT mode.

The use of ozone, ozone plus UV radiation, and aerobic microorganisms in the purification of some agro-industrial wastewaters.

PubMed

Benitez, F Javier; Acero, Juan L; Gonzalez, Teresa; Garcia, Juan

2002-08-01

The oxidation of the pollutant organic matter present in wastewaters generated during different stages in the black table-olive industry was investigated by using ozone alone or combined with UV radiation; by using aerobic microorganisms; and finally, by aerobic degradation of the previously ozonated wastewaters. In the ozonation processes, the removal of substrate (COD) and aromatic compounds, the decreases in BOD5 and pH, and the ozone consumed in the reaction were evaluated. A kinetic study was conducted that led to the evaluation of the stoichiometric ratio for the chemical reaction, as well as the rate constants for the substrate reduction and ozone disappearance. In the single aerobic degradation treatment, the evolution of substrate and biomass was monitored during the process, and a kinetic study was performed by applying the Contois model to the experimental data, giving the specific biokinetic constant, the cell yield coefficient, and the rate constant for the microorganism death phase. Finally, a combined process was performed, consisting in the aerobic degradation of pre-ozonated wastewaters, and the effect of such chemical pretreatment on the substrate removal and kinetic parameters of the later biological stage is discussed.

Interior microelectrolysis oxidation of polyester wastewater and its treatment technology.

PubMed

Yang, Xiaoyi

2009-09-30

This paper has investigated the effects of interior microelectrolysis pretreatment on polyester wastewater treatment and analyzed its mechanism on COD and surfactant removal. The efficiency of interior microelectrolysis is mainly influenced by solution pH, aeration and reaction time. Contaminants can be removed not only by redox reaction and flocculation in the result of ferrous and ferric hydroxides but also by electrophoresis under electric fields created by electron flow. pH confirms the chemical states of surfactants, Fe(II)/Fe(III) ratio and the redox potential, and thus influences the effects of electrophoresis, flocculation and redox action on contaminant removal. Anaerobic and aerobic batch tests were performed to study the degradation of polyester wastewater. The results imply that interior microelectrolysis and anaerobic pretreatment are lacking of effectiveness if applied individually in treating polyester wastewater in spite of their individual advantages. The interior microelectrolysis-anaerobic-aerobic process was investigated to treat polyester wastewater with comparison with interior microelectrolysis-aerobic process and anaerobic-aerobic process. High COD removal efficiencies have been gotten by the combination of interior microelectrolysis with anaerobic technology and aerobic technology. The results also imply that only biological treatment was less effective in polyester wastewater treatment.

State of the art of aerobic granulation in continuous flow bioreactors.

PubMed

Kent, Timothy R; Bott, Charles B; Wang, Zhi-Wu

In the wake of the success of aerobic granulation in sequential batch reactors (SBRs) for treating wastewater, attention is beginning to turn to continuous flow applications. This is a necessary step given the advantages of continuous flow treatment processes and the fact that the majority of full-scale wastewater treatment plants across the world are operated with aeration tanks and clarifiers in a continuous flow mode. As in SBRs, applying a selection pressure, based on differences in either settling velocity or the size of the biomass, is essential for successful granulation in continuous flow reactors (CFRs). CFRs employed for aerobic granulation come in multiple configurations, each with their own means of achieving such a selection pressure. Other factors, such as bioaugmentation and hydraulic shear force, also contribute to aerobic granulation to some extent. Besides the formation of aerobic granules, long-term stability of aerobic granules is also a critical issue to be addressed. Inorganic precipitation, special inocula, and various operational optimization strategies have been used to improve granule long-term structural integrity. Accumulated studies reviewed in this work demonstrate that aerobic granulation in CFRs is capable of removing a wide spectrum of contaminants and achieving properties generally comparable to those in SBRs. Despite the notable research progress made toward successful aerobic granulation in lab-scale CFRs, to the best of our knowledge, there are only three full-scale tests of the technique, two being seeded with anammox-supported aerobic granules and the other with conventional aerobic granules; two other process alternatives are currently in development. Application of settling- or size-based selection pressures and feast/famine conditions are especially difficult to implement to these and similar mainstream systems. Future research efforts needs to be focused on the optimization of the granule-to-floc ratio, enhancement of granule activity, improvement of long-term granule stability, and a better understanding of aerobic granulation mechanisms in CFRs, especially in full-scale applications. Copyright © 2018 Elsevier Inc. All rights reserved.

Removal of Pesticides and Inorganic Contaminants in Anaerobic and Aerobic Biological Contactors

EPA Science Inventory

This presentation contains data on the removal of pesticides (acetochlor, clethodim, dicrotophos), ammonia, nitrate, bromate and perchlorate through aerobic and anaerobic biological treatment processes.

Thermodynamic analysis of the energy recovery from the aerobic bioconversion of solid urban waste organic fraction.

PubMed

Di Maria, Francesco; Benavoli, Manuel; Zoppitelli, Mirco

2008-01-01

Waste management is of the utmost importance for many countries and especially for highly developed ones due to its implications on society. In particular, proper treatment before disposal of the solid urban waste organic fraction is one of the main issues that is addressed in waste management. In fact, the organic fraction is particularly reactive and if disposed in sanitary landfills without previous adequate treatment, a large amount of dangerous and polluting gaseous, liquid and solid substances can be produced. Some waste treatment processes can also present an opportunity to produce other by-products like energy, recycled materials and other products with both economic and environmental benefits. In this paper, the aerobic treatment of the organic fraction of solid urban waste, performed in a biocell plant with the possibility of recovering heat for civil or industrial needs, was examined from the thermodynamic point of view. A theoretical model was proposed both for the biological process of the organic fraction, as well as for the heat recovery system. The most significant results are represented and discussed.

The effect of three different exercise training modalities on cognitive and physical function in a healthy older population.

PubMed

Coetsee, Carla; Terblanche, Elmarie

2017-01-01

Older adults are encouraged to participate in regular physical activity to counter the age-related declines in physical and cognitive health. Literature on the effect of different exercise training modalities (aerobic vs resistance) on these health-related outcomes is not only sparse, but results are inconsistent. In general, it is believed that exercise has a positive effect on executive cognitive function, possibly because of the physiological adaptations through increases in fitness. Indications are that high-intensity interval training is a potent stimulus to improve cardiovascular fitness, even in older adults; however, its effect on cognitive function has not been studied before. Therefore, the purpose of this study was to compare the effects of resistance training, high-intensity aerobic interval training and moderate continuous aerobic training on the cognitive and physical functioning of healthy older adults. Sixty-seven inactive individuals (55 to 75 years) were randomly assigned to a resistance training (RT) group ( n  = 22), high-intensity aerobic interval training (HIIT) group ( n  = 13), moderate continuous aerobic training (MCT) group ( n  = 13) and a control (CON) group ( n  = 19) for a period of 16 weeks. Cognitive function was assessed with a Stroop task and physical function with the Timed-Up-and-Go (TUG) and submaximal Bruce treadmill tests. No significant GROUP x TIME interaction was found for Stroop reaction time ( P  > .05). The HIIT group showed the greatest practical significant improvement in reaction time on the information processing task, i.e. Stroop Neutral (ES = 1.11). MCT group participants had very large practical significant improvements in reaction time on the executive cognitive tasks, i.e. Stroop Incongruent and Interference (ES = 1.28 and 1.31, respectively). The HIIT group showed the largest practically significant increase in measures of physical function, i.e. walking endurance (ES = 0.91) and functional mobility (ES = 0.36). MCT and RT proved to be superior to HIIT for the enhancement of older individuals' executive cognitive function; whereas HIIT were most beneficial for improvement in information processing speed. HIIT also induced the largest gains in physical function.

Interactive effects of obesity and physical fitness on risk of ischemic heart disease.

PubMed

Crump, C; Sundquist, J; Winkleby, M A; Sundquist, K

2017-02-01

Obesity and low physical fitness are known risk factors for ischemic heart disease (IHD), but their interactive effects are unclear. Elucidation of interactions between these common, modifiable risk factors may help inform more effective preventive strategies. We examined interactive effects of obesity, aerobic fitness and muscular strength in late adolescence on risk of IHD in adulthood in a large national cohort. We conducted a national cohort study of all 1 547 407 military conscripts in Sweden during 1969-1997 (97-98% of all 18-year-old males each year). Aerobic fitness, muscular strength and body mass index (BMI) measurements were examined in relation to IHD identified from outpatient and inpatient diagnoses through 2012 (maximum age 62 years). There were 38 142 men diagnosed with IHD in 39.7 million person years of follow-up. High BMI or low aerobic fitness (but not muscular strength) was associated with higher risk of IHD, adjusting for family history and socioeconomic factors. The combination of high BMI (overweight/obese vs normal) and low aerobic fitness (lowest vs highest tertile) was associated with highest IHD risk (incidence rate ratio, 3.11; 95% confidence interval (CI), 2.91-3.31; P<0.001). These exposures had no additive and a negative multiplicative interaction (that is, their combined effect was less than the product of their separate effects). Low aerobic fitness was a strong risk factor even among those with normal BMI. In this large cohort study, low aerobic fitness or high BMI at age 18 was associated with higher risk of IHD in adulthood, with a negative multiplicative interaction. Low aerobic fitness appeared to account for a similar number of IHD cases among those with normal vs high BMI (that is, no additive interaction). These findings suggest that interventions to prevent IHD should begin early in life and include not only weight control but aerobic fitness, even among persons of normal weight.

Maximal aerobic and anaerobic power generation in large crocodiles versus mammals: implications for dinosaur gigantothermy.

PubMed

Seymour, Roger S

2013-01-01

Inertial homeothermy, the maintenance of a relatively constant body temperature that occurs simply because of large size, is often applied to large dinosaurs. Moreover, biophysical modelling and actual measurements show that large crocodiles can behaviourally achieve body temperatures above 30°C. Therefore it is possible that some dinosaurs could achieve high and stable body temperatures without the high energy cost of typical endotherms. However it is not known whether an ectothermic dinosaur could produce the equivalent amount of muscular power as an endothermic one. To address this question, this study analyses maximal power output from measured aerobic and anaerobic metabolism in burst exercising estuarine crocodiles, Crocodylusporosus, weighing up to 200 kg. These results are compared with similar data from endothermic mammals. A 1 kg crocodile at 30°C produces about 16 watts from aerobic and anaerobic energy sources during the first 10% of exhaustive activity, which is 57% of that expected for a similarly sized mammal. A 200 kg crocodile produces about 400 watts, or only 14% of that for a mammal. Phosphocreatine is a minor energy source, used only in the first seconds of exercise and of similar concentrations in reptiles and mammals. Ectothermic crocodiles lack not only the absolute power for exercise, but also the endurance, that are evident in endothermic mammals. Despite the ability to achieve high and fairly constant body temperatures, therefore, large, ectothermic, crocodile-like dinosaurs would have been competitively inferior to endothermic, mammal-like dinosaurs with high aerobic power. Endothermy in dinosaurs is likely to explain their dominance over mammals in terrestrial ecosystems throughout the Mesozoic.

Aerobic Exercise and Other Healthy Lifestyle Factors That Influence Vascular Aging

ERIC Educational Resources Information Center

Santos-Parker, Jessica R.; LaRocca, Thomas J.; Seals, Douglas R

2014-01-01

Cardiovascular diseases (CVDs) remain the leading cause of death in the United States and other modern societies. Advancing age is the major risk factor for CVD, primarily due to stiffening of the large elastic arteries and the development of vascular endothelial dysfunction. In contrast, regular aerobic exercise protects against the development…

Economic Evaluation of Two Biological Processes for Treatment of Ball Powder Production Wastewater

DTIC Science & Technology

1989-02-01

Collection and Equalization 2-1 2.2 System 200 - pH and Nutrient Control 2-1 2.3 System 300 - Extended Aeration and Aerobic Digestion 2-4 2.4 System...400 - Sequencing Batch Reactor and Aerobic Digestion 2-4 2.5 System 500 - Sludge Dewatering and Control Building 2-7 1 3.0 COST ESTIMATION AND...Extended Aeration and Aerobic Digestion 2-5 2.4 400 - Sequencing Batch Reactors and Aerobic Digestion 2-6 2.5 500 - Sludge Dewatering 2-8 Artur D Little

Enhanced performance of denitrifying sulfide removal process at high carbon to nitrogen ratios under micro-aerobic condition.

PubMed

Chen, Chuan; Zhang, Ruo-Chen; Xu, Xi-Jun; Fang, Ning; Wang, Ai-Jie; Ren, Nan-Qi; Lee, Duu-Jong

2017-05-01

The success of denitrifying sulfide removal (DSR) processes, which simultaneously degrade sulfide, nitrate and organic carbon in the same reactor, counts on synergetic growths of autotrophic and heterotrophic denitrifiers. Feeding wastewaters at high C/N ratio would stimulate overgrowth of heterotrophic bacteria in the DSR reactor so deteriorating the growth of autotrophic denitrifiers. The DSR tests at C/N=1.26:1, 2:1 or 3:1 and S/N =5:6 or 5:8 under anaerobic (control) or micro-aerobic conditions were conducted. Anaerobic DSR process has <50% sulfide removal with no elemental sulfur transformation. Under micro-aerobic condition to remove <5% sulfide by chemical oxidation pathway, 100% sulfide removal is achieved by the DSR consortia. Continuous-flow tests under micro-aerobic condition have 70% sulfide removal and 55% elemental sulfur recovery. Trace oxygen enhances activity of sulfide-oxidizing, nitrate-reducing bacteria to accommodate properly the wastewater with high C/N ratios. Copyright © 2017 Elsevier Ltd. All rights reserved.

Removal of oxytetracycline and determining its biosorption properties on aerobic granular sludge.

PubMed

Mihciokur, Hamdi; Oguz, Merve

2016-09-01

This study investigates biosorption of Oxytetracycline, a broad-spectrum antibiotic, using aerobic granular sludge as an adsorbent in aqueous solutions. A sequencing batch reactor fed by a synthetic wastewater was operated to create aerobic granular sludge. Primarily, the pore structure and surface area of granular sludge, the chemical structure and the molecular sizes of the pharmaceutical, operating conditions, such as pH, stirring rate, initial concentration of Oxytetracycline, during adsorption process was verified. Subsequently, thermodynamic and kinetic aspects of the adsorption were examined and adsorption isotherm studies were carried out. It was shown that the aerobic granular sludge was a good alternative for biosorption of this pharmaceutical. The pharmaceutical was adsorbed better at pH values of 6-8. The adsorption efficiency increased with rising ionic strength. Also, it was seen that the adsorption process was an exothermic process in terms of thermodynamics. The adsorption can be well explained by Langmuir isotherm model. Copyright © 2016 Elsevier B.V. All rights reserved.

Absolute and relative reliability of acute effects of aerobic exercise on executive function in seniors.

PubMed

Donath, Lars; Ludyga, Sebastian; Hammes, Daniel; Rossmeissl, Anja; Andergassen, Nadin; Zahner, Lukas; Faude, Oliver

2017-10-25

Aging is accompanied by a decline of executive function. Aerobic exercise training induces moderate improvements of cognitive domains (i.e., attention, processing, executive function, memory) in seniors. Most conclusive data are obtained from studies with dementia or cognitive impairment. Confident detection of exercise training effects requires adequate between-day reliability and low day-to-day variability obtained from acute studies, respectively. These absolute and relative reliability measures have not yet been examined for a single aerobic training session in seniors. Twenty-two healthy and physically active seniors (age: 69 ± 3 y, BMI: 24.8 ± 2.2, VO 2peak : 32 ± 6 mL/kg/bodyweight) were enrolled in this randomized controlled cross-over study. A repeated between-day comparison [i.e., day 1 (habituation) vs. day 2 & day 2 vs. day 3] of executive function testing (Eriksen-Flanker-Test, Stroop-Color-Test, Digit-Span, Five-Point-Test) before and after aerobic cycling exercise at 70% of the heart rate reserve [0.7 × (HR max - HR rest )] was conducted. Reliability measures were calculated for pre, post and change scores. Large between-day differences between day 1 and 2 were found for reaction times (Flanker- and Stroop Color testing) and completed figures (Five-Point test) at pre and post testing (0.002 < p < 0.05, 0.16 < ɳ p 2  < 0.38). These differences notably declined when comparing day 2 and 3. Absolute between days variability (CoV) dropped from 10 to 5% when comparing day 2 vs. day 3 instead of day 1 vs. day 2. Also ICC ranges increased from day 1 vs. day 2 (0.65 < ICC < 0.87) to day 2 vs. day 3 (0.40 < ICC < 0.93). Interestingly, reliability measures for pre-post change scores were low (0.02 < ICC < 0.71). These data did not improve when comparing day 2 with day 3. During inhibition tests, reaction times showed excellent reliability values compared to the poor to fair reliability of accuracy. Notable habituation to the whole testing procedure should be considered as it increased the reliability of different executive function tests. Change scores of executive function after acute aerobic exercise cannot be detected reliably. Large intra- and inter-individual of responses to acute aerobic exercise in seniors can be presumed.

Time series analysis of aerobic bacterial flora during Miso fermentation.

PubMed

Onda, T; Yanagida, F; Tsuji, M; Shinohara, T; Yokotsuka, K

2003-01-01

This article reports a microbiological study of aerobic mesophilic bacteria that are present during the fermentation process of Miso. Aerobic bacteria were enumerated and isolated from Miso during fermentation and divided into nine groups using traditional phenotypic tests. The strains were identified by biochemical analysis and 16S rRNA sequence analysis. They were identified as Bacillus subtilis, B. amyloliquefaciens, Kocuria kristinae, Staphylococcus gallinarum and S. kloosii. All strains were sensitive to the bacteriocins produced by the lactic acid bacteria isolated from Miso. The dominant species among the undesirable species throughout the fermentation process were B. subtilis and B. amyloliquefaciens. It is suggested that bacteriocin-producing lactic acid bacteria are effective in the growth prevention of aerobic bacteria in Miso. This study has provided useful information for controlling of bacterial flora during Miso fermentation.

Role of seagrass photosynthesis in root aerobic processes.

PubMed

Smith, R D; Dennison, W C; Alberte, R S

1984-04-01

The role of shoot photosynthesis as a means of supporting aerobic respiration in the roots of the seagrass Zostera marina was examined. O(2) was transported rapidly (10-15 minutes) from the shoots to the root-rhizome tissues upon shoot illumination. The highest rates of transport were in shoots possessing the greatest biomass and leaf area. The rates of O(2) transport do not support a simple gas phase diffusion mechanism. O(2) transport to the root-rhizome system supported aerobic root respiration and in many cases exceeded respiratory requirements leading to O(2) release from the subterranean tissue. Release of O(2) can support aerobic processes in reducing sediments typical of Z. marina habitats. Since the root-rhizome respiration is supported primarily under shoot photosynthetic conditions, then the daily period of photosynthesis determines the diurnal period of root aerobiosis.

Bacterial community dynamics in long-term operation of a pilot plant using aerobic granular sludge to treat pig slurry.

PubMed

Fra-Vázquez, A; Morales, N; Figueroa, M; Val Del Río, A; Regueiro, L; Campos, J L; Mosquera-Corral, A

2016-09-01

Aerobic granular sludge represents an interesting approach for simultaneous organic matter and nitrogen removal in wastewater treatment plants. However, the information about microbial communities in aerobic granular systems dealing with industrial wastewater like pig slurry is limited. Herein, bacterial diversity and dynamics were assessed in a pilot scale plant using aerobic granular sludge for organic matter and nitrogen elimination from swine slurry during more than 300 days. Results indicated that bacterial composition evolved throughout the operational period from flocculent activated sludge, used as inoculum, to mature aerobic granules. Bacterial diversity increased at the beginning of the granulation process and then declined due to the application of transient organic matter and nitrogen loads. The operational conditions of the pilot plant and the degree of granulation determined the microbial community of the aerobic granules. Brachymonas, Zoogloea and Thauera were attributed with structural function as they are able to produce extracellular polymeric substances to maintain the granular structure. Nitrogen removal was justified by partial nitrification (Nitrosomonas) and denitrification (Thauera and Zoogloea), while Comamonas was identified as the main organic matter oxidizing bacteria. Overall, clear links between bacterial dynamics and composition with process performance were found and will help to predict their biological functions in wastewater ecosystems improving the future control of the process. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1212-1221, 2016. © 2016 American Institute of Chemical Engineers.

Climate change and temperature-dependent biogeography: oxygen limitation of thermal tolerance in animals.

PubMed

Pörtner, H O

2001-04-01

Recent years have shown a rise in mean global temperatures and a shift in the geographical distribution of ectothermic animals. For a cause and effect analysis the present paper discusses those physiological processes limiting thermal tolerance. The lower heat tolerance in metazoa compared with unicellular eukaryotes and bacteria suggests that a complex systemic rather than molecular process is limiting in metazoa. Whole-animal aerobic scope appears as the first process limited at low and high temperatures, linked to the progressively insufficient capacity of circulation and ventilation. Oxygen levels in body fluids may decrease, reflecting excessive oxygen demand at high temperatures or insufficient aerobic capacity of mitochondria at low temperatures. Aerobic scope falls at temperatures beyond the thermal optimum and vanishes at low or high critical temperatures when transition to an anaerobic mitochondrial metabolism occurs. The adjustment of mitochondrial densities on top of parallel molecular or membrane adjustments appears crucial for maintaining aerobic scope and for shifting thermal tolerance. In conclusion, the capacity of oxygen delivery matches full aerobic scope only within the thermal optimum. At temperatures outside this range, only time-limited survival is supported by residual aerobic scope, then anaerobic metabolism and finally molecular protection by heat shock proteins and antioxidative defence. In a cause and effect hierarchy, the progressive increase in oxygen limitation at extreme temperatures may even enhance oxidative and denaturation stress. As a corollary, capacity limitations at a complex level of organisation, the oxygen delivery system, define thermal tolerance limits before molecular functions become disturbed.

Characteristics of sludge reduction in an integrated pretreatment and aerobic digestion process.

PubMed

Hwang, S; Jang, H; Lee, M; Song, J; Kim, S

2006-01-01

In this study, integrated pretreatments and aerobic digestion processes were investigated in order to provide a feasible alternative that can achieve effective sludge reduction. An ozone treatment in the presence of ionic manganese, a catalyst, increased the sludge reduction ratio three times higher than that of a single ozonation, presumably due to an increase in OH radical production. The ozone treatment yielded the effective sludge reduction ratio with an increasing ozone dosage, and an effective dosage of the catalyst was found to be 4 mg-Mn/g-TS. When a mechanical pretreatment and an ozone/catalyst were applied in a series, the integrated process, even at a half mechanical intensity and a half level of ozone dosage, showed higher and faster sludge reduction than each single process did. In addition, the integrated pretreatment process showed the highest dewaterability of the treated sludges. A ratio of sludge cake generation, which was newly introduced to quantify overall performance of sludge treatment processes, showed that the integrated pretreatment followed by the aerobic digestion yielded approximately a half of the sludge cake volume compared to the single aerobic digestion. Therefore, the integrated pretreatment can be a feasible method for the effective reduction of total suspended solid and the final volume.

Aerobic microbial enhanced oil recovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Torsvik, T.; Gilje, E.; Sunde, E.

1995-12-31

In aerobic MEOR, the ability of oil-degrading bacteria to mobilize oil is used to increase oil recovery. In this process, oxygen and mineral nutrients are injected into the oil reservoir in order to stimulate growth of aerobic oil-degrading bacteria in the reservoir. Experiments carried out in a model sandstone with stock tank oil and bacteria isolated from offshore wells showed that residual oil saturation was lowered from 27% to 3%. The process was time dependent, not pore volume dependent. During MEOR flooding, the relative permeability of water was lowered. Oxygen and active bacteria were needed for the process to takemore » place. Maximum efficiency was reached at low oxygen concentrations, approximately 1 mg O{sub 2}/liter.« less

[Characteristics of novel wastewater treatment technology by swimming bed combined with aerobic granular sludge].

PubMed

Zhang, Yan; Wang, Yong-sheng; Bai, Yu-hua; Chen, Chen; Lü, Jian; Zhang, Jie

2007-10-01

Swimming bed combined with aerobic granular sludge as a novel technology for wastewater treatment was developed, which was on the basis of the biofilm process and activated sludge process, and results demonstrated notable performance of high-efficiency treatment capability and sludge reduction. Even when hydraulic retention time (HRT) was only at 3.2 h with average COD volumetric loading of 2.03 kg/(m3 x d) and NH4(+)-N of 0.52 kg/(m3 X d), 90.9% of average COD removal rate and 98.3% of NH4(+)-N removal rate were achieved. Aerobic granular sludge appeared with spherical or rod shape after 16 days operation. Mixed liquor suspended solid (MLSS) concentrations in the reactor reached 5,640 mg/L at the highest during operation period, and the average ratio of mixed liquor volatile suspended solid (MLVSS) to MLSS reached 0.87. Furthermore, microscopic observation of biofilm and aerobic granules revealed much presence of protozoa and metazoa on the biofilm and suspended sludge, and this long food chain can contribute to the sludge reduction. Only 0. 175 5 of sludge yields (MLSS/ CODremoved) was obtained in the experiment, which was only about 50% of the conventional aerobic processes.

Strengthen effects of dominant strains on aerobic digestion and stabilization of the residual sludge.

PubMed

Liu, Yongjun; Gao, Min; Zhang, Aining; Liu, Zhe

2017-07-01

In order to strengthen the aerobic digestion of residual sludge, shorten the time of sludge stabilization and further reduce operating costs, 3 dominant strains identified as Pseudomonas sp. L3, Acinetobacter sp. L16 and Bacillus sp. L19 were isolated from long-term aerobic digestion sludge. Results showed that the sludge stabilization time were reduced by 3-4days compared with the control when the dominant strains were added to the process of sludge aerobic digestion. The addition of dominant strains accelerated the accumulation of TOC, nitrate nitrogen and ammonia nitrogen in the digestive solution at different levels, and it was beneficial to the dissolution of phosphorus. Controlling DO 3-5mg/L, pH 6.5, the strains of Pseudomonas sp. L3 and Bacillus sp. L19 were combined dosing with the dosage of 2% in the process of sludge aerobic digestion, compared with the control, digestion rates of TOC and MLSS were increased about 19% and 16%, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of Cognitive Training with and without Aerobic Exercise on Cognitively-Demanding Everyday Activities

PubMed Central

McDaniel, Mark A.; Binder, Ellen F.; Bugg, Julie M.; Waldum, Emily R.; Dufault, Carolyn; Meyer, Amanda; Johanning, Jennifer; Zheng, Jie; Schechtman, Kenneth B.; Kudelka, Chris

2015-01-01

We investigated the potential benefits of a novel cognitive training protocol and an aerobic exercise intervention, both individually and in concert, on older adults’ performances in laboratory simulations of select real-world tasks. The cognitive training focused on a range of cognitive processes, including attentional coordination, prospective memory, and retrospective-memory retrieval, processes that are likely involved in many everyday tasks, and that decline with age. Primary outcome measures were three laboratory tasks that simulated everyday activities: Cooking Breakfast, Virtual Week, and Memory for Health Information. Two months of cognitive training improved older adults’ performance on prospective memory tasks embedded in Virtual Week. Cognitive training, either alone or in combination with six months of aerobic exercise, did not significantly improve Cooking Breakfast or Memory for Health Information. Although gains in aerobic power were comparable to previous reports, aerobic exercise did not produce improvements for the primary outcome measures. Discussion focuses on the possibility that cognitive training programs that include explicit strategy instruction and varied practice contexts may confer gains to older adults for performance on cognitively challenging everyday tasks. PMID:25244489

Comparison of a Four-Section Spindle and Stomacher for Efficacy of Detaching Microorganisms from Fresh Vegetables.

PubMed

Kim, Do-Kyun; Kim, Soo-Ji; Kang, Dong-Hyun

2015-07-01

This study was undertaken to compare the effect of the spindle and stomacher for detaching microorganisms from fresh vegetables. The spindle is an apparatus for detaching microorganisms from food surfaces, which was developed in our laboratory. When processed with the spindle, food samples were barely disrupted, the original shape was maintained, and the diluent was clear, facilitating further detection analysis more easily than with stomacher treatment. The four-section spindle consists of four sample bag containers (A, B, C, and D) to economize time and effort by simultaneously processing four samples. The aerobic plate counts (APC) of 50 fresh vegetable samples were measured following spindle and stomacher treatment. Correlations between the two methods for each section of the spindle and stomacher were very high (R(2) = 0.9828 [spindle compartment A; Sp A], 0.9855 [Sp B], 0.9848 [Sp C], and 0.9851 [Sp D]). One-tenth milliliter of foodborne pathogens suspensions was inoculated onto surfaces of food samples, and ratios of spindle-to-stomacher enumerations were close to 1.00 log CFU/g between every section of the spindle and stomacher. One of the greatest features of the spindle is that it can treat large-sized samples that exceed 200 g. Uncut whole apples, green peppers, potatoes, and tomatoes were processed by the spindle and by hand massaging by 2 min. Large-sized samples were also assayed for aerobic plate count and recovery of the three foodborne pathogens, and the difference between each section of the spindle and hand massaging was not significant (P > 0.05). This study demonstrated that the spindle apparatus can be an alternative device for detaching microorganisms from all fresh vegetable samples for microbiological analysis by the food processing industry.

Maximal Aerobic and Anaerobic Power Generation in Large Crocodiles versus Mammals: Implications for Dinosaur Gigantothermy

PubMed Central

Seymour, Roger S.

2013-01-01

Inertial homeothermy, the maintenance of a relatively constant body temperature that occurs simply because of large size, is often applied to large dinosaurs. Moreover, biophysical modelling and actual measurements show that large crocodiles can behaviourally achieve body temperatures above 30°C. Therefore it is possible that some dinosaurs could achieve high and stable body temperatures without the high energy cost of typical endotherms. However it is not known whether an ectothermic dinosaur could produce the equivalent amount of muscular power as an endothermic one. To address this question, this study analyses maximal power output from measured aerobic and anaerobic metabolism in burst exercising estuarine crocodiles, Crocodylusporosus , weighing up to 200 kg. These results are compared with similar data from endothermic mammals. A 1 kg crocodile at 30°C produces about 16 watts from aerobic and anaerobic energy sources during the first 10% of exhaustive activity, which is 57% of that expected for a similarly sized mammal. A 200 kg crocodile produces about 400 watts, or only 14% of that for a mammal. Phosphocreatine is a minor energy source, used only in the first seconds of exercise and of similar concentrations in reptiles and mammals. Ectothermic crocodiles lack not only the absolute power for exercise, but also the endurance, that are evident in endothermic mammals. Despite the ability to achieve high and fairly constant body temperatures, therefore, large, ectothermic, crocodile-like dinosaurs would have been competitively inferior to endothermic, mammal-like dinosaurs with high aerobic power. Endothermy in dinosaurs is likely to explain their dominance over mammals in terrestrial ecosystems throughout the Mesozoic. PMID:23861968

Occurrence and Fate of Trace Contaminants during Aerobic and Anaerobic Sludge Digestion and Dewatering.

PubMed

Guerra, Paula; Kleywegt, Sonya; Payne, Michael; Svoboda, M Lewina; Lee, Hing-Biu; Reiner, Eric; Kolic, Terry; Metcalfe, Chris; Smyth, Shirley Anne

2015-07-01

Digestion of municipal wastewater biosolids is a necessary prerequisite to their beneficial use in land application, in order to protect public health and the receiving environment. In this study, 13 pharmaceuticals and personal care products (PPCPs), 11 musks, and 17 polybrominated diphenyl ethers were analyzed in 84 samples including primary sludge, waste activated sludge, digested biosolids, dewatered biosolids, and dewatering centrate or filtrate collected from five wastewater treatment plants with aerobic or anaerobic digestion. Aerobic digestion processes were sampled during both warm and cold temperatures to analyze seasonal differences. Among the studied compounds, triclosan, triclocarban, galaxolide, and BDE-209 were the substances most frequently detected under different treatment processes at levels up to 30,000 ng/g dry weight. Comparing aerobic and anaerobic digestion, it was observed that the levels of certain PPCPs and musks were significantly higher in anaerobically digested biosolids, relative to the residues from aerobic digestion. Therefore, aerobic digestion has the potential advantage of reducing levels of PPCPs and musks. On the other hand, anaerobic digestion has the advantage of recovering energy from the biosolids in the form of combustible gases while retaining the nutrient and soil conditioning value of this resource. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Sludge stabilization through aerobic digestion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartman, R.B.; Smith, D.G.; Bennett, E.R.

1979-10-01

The aerobic digestion process with certain modifications is evaluated as an alternative for sludge processing capable of developing a product with characteristics required for land application. Environmental conditions, including temperature, solids concentration, and digestion time, that affect the aerobic digestion of a mixed primary sludge-trickling filter humus are investigated. Variations in these parameters that influence the characteristics of digested sludge are determined, and the parameters are optimized to: provide the maximum rate of volatile solids reduction; develop a stable, nonodorous product sludge; and provide the maximum rate of oxidation of the nitrogenous material present in the feed sludge. (3 diagrams,more » 9 graphs, 15 references, 3 tables)« less

Use of total of Escherichia coli counts to assess the hygienic characteristics of a beef carcass dressing process.

PubMed

Gill, C O; McGinnis, J C; Badoni, M

1996-08-01

Swab samples were obtained from 3 sites on the surfaces of beef carcasses passing through a high speed dressing process, with 24 samples from each site being obtained at each of 4 points in the process. The aerobic microflora recovered from each swab after incubation at 25 degrees C was enumerated and characterized, and numbers of coliforms and Escherichia coli were determined. The data on aerobic flora indicated that skinning results in similar contamination of all 3 sites, that further deposition of bacteria at the brisket site occurs after skinning, and that trimming and washing achieve modest decontamination of the neck and brisket site, and extensive decontamination of the rump site. Changes in flora compositions during processing were too limited to much affect the assessment based on the aerobic flora total counts alone. The E. coli data indicated that during skinning the rump site was more heavily contaminated with faecal organisms than the other sites, that contamination of the brisket site is little altered between skinning and carcass splitting, although there is an extensive redistribution of E. coli at the neck site and sporadic, limited decontamination of the rump site, and that trimming and washing do not decontaminate the neck or rump sites, but that the rump site is extensively decontaminated by trimming. There was good correlation between E. coli and coliform counts, but weak correlation between E. coli and aerobic, 25 degrees C, counts. The findings suggest that assessments of beef carcass dressing processes for Hazard Analysis: Critical Control Point (HACCP) purposes should be based on enumerations of E. coli, or perhaps coliforms, rather than of the aerobic flora, to avoid important misunderstandings of the hygienic effects of the various operations in a process.

Aerobic biodegradation of trichloroethene without auxiliary substrates.

PubMed

Schmidt, Kathrin R; Gaza, Sarah; Voropaev, Andrey; Ertl, Siegmund; Tiehm, Andreas

2014-08-01

Trichloroethene (TCE) represents a priority pollutant and is among the most frequently detected contaminants in groundwater. The current bioremediation measures have certain drawbacks like e.g. the need for auxiliary substrates. Here, the aerobic biodegradation of TCE as the sole growth substrate is demonstrated. This new process of metabolic TCE degradation was first detected in groundwater samples. TCE degradation was stable in an enriched mixed bacterial culture in mineral salts medium for over five years and repeated transfers of the culture resulting in a 10(10) times dilution of the original groundwater. Aerobic TCE degradation resulted in stoichiometric chloride formation. Stable carbon isotope fractionation was observed providing a reliable analytical tool to assess this new biodegradation process at field sites. The results suggest that aerobic biodegradation of TCE without auxiliary substrate could be considered as an option for natural attenuation or engineered bioremediation of contaminated sites. Copyright © 2014 Elsevier Ltd. All rights reserved.

Radiation sensitivity of foodborne pathogens in meat byproducts with different packaging

NASA Astrophysics Data System (ADS)

Yong, Hae In; Kim, Hyun-Joo; Nam, Ki Chang; Kwon, Joong Ho; Jo, Cheorun

2015-10-01

The aim of this study was to determine radiation sensitivity of Escherichia coli O157:H7 and Listeria monocytogenes in edible meat byproducts. Seven beef byproducts (heart, liver, lung, lumen, omasum, large intestine, and small intestine) and four pork byproducts (heart, large intestine, liver, and small intestine) were used. Electron beam irradiation significantly reduced the numbers of pathogenic microorganisms in meat byproducts and no viable cells were detected in both aerobically- and vacuum-packaged samples irradiated at 4 kGy. Meat byproducts packed under vacuum had higher D10 value than the ones packed aerobically. No significant difference was observed between the D10 values of E. coli O157:H7 and L. monocytogenes inoculated in either aerobically or vacuum packaged samples. These results suggest that low-dose electron beam irradiation can significantly decrease microbial numbers and reduce the risk of meat byproduct contamination by the foodborne pathogens.

Comparative performance evaluation of full-scale anaerobic and aerobic wastewater treatment processes in Brazil.

PubMed

von Sperling, M; Oliveira, S C

2009-01-01

This article evaluates and compares the actual behavior of 166 full-scale anaerobic and aerobic wastewater treatment plants in operation in Brazil, providing information on the performance of the processes in terms of the quality of the generated effluent and the removal efficiency achieved. The observed results of effluent concentrations and removal efficiencies of the constituents BOD, COD, TSS (total suspended solids), TN (total nitrogen), TP (total phosphorus) and FC (faecal or thermotolerant coliforms) have been compared with the typical expected performance reported in the literature. The treatment technologies selected for study were: (a) predominantly anaerobic: (i) septic tank + anaerobic filter (ST + AF), (ii) UASB reactor without post-treatment (UASB) and (iii) UASB reactor followed by several post-treatment processes (UASB + POST); (b) predominantly aerobic: (iv) facultative pond (FP), (v) anaerobic pond followed by facultative pond (AP + FP) and (vi) activated sludge (AS). The results, confirmed by statistical tests, showed that, in general, the best performance was achieved by AS, but closely followed by UASB reactor, when operating with any kind of post-treatment. The effluent quality of the anaerobic processes ST + AF and UASB reactor without post-treatment was very similar to the one presented by facultative pond, a simpler aerobic process, regarding organic matter.

Influence of substrate surface loading on the kinetic behaviour of aerobic granules.

PubMed

Liu, Yu; Liu, Yong-Qiang; Wang, Zhi-Wu; Yang, Shu-Fang; Tay, Joo-Hwa

2005-06-01

In the aerobic granular sludge reactor, the substrate loading is related to the size of the aerobic granules cultivated. This study investigated the influence of substrate surface loading on the growth and substrate-utilization kinetics of aerobic granules. Results showed that microbial surface growth rate and surface biodegradation rate are fairly related to the substrate surface loading by the Monod-type equation. In this study, both the theoretical maximum growth yield and the Pirt maintenance coefficient were determined. It was found that the estimated theoretical maximum growth yield of aerobic granules was as low as 0.2 g biomass g(-1) chemical oxygen demand (COD) and 10-40% of input substrate-COD was consumed through the maintenance metabolism, while experimental results further showed that the unit oxygen uptake by aerobic granules was 0.68 g oxygen g(-1) COD, which was much higher than that reported in activated sludge processes. Based on the growth yield and unit oxygen uptake determined, an oxidative assimilation equation of acetate-fed aerobic granules was derived; and this was confirmed by respirometric tests. In aerobic granular culture, about 74% of the input substrate-carbon was converted to carbon dioxide. The growth yield of aerobic granules was three times lower than that of activated sludge. It is likely that high carbon dioxide production is the main cause of the low growth yield of aerobic granules, indicating a possible energy uncoupling in aerobic granular culture.

Roles of Thermophiles and Fungi in Bitumen Degradation in Mostly Cold Oil Sands Outcrops

PubMed Central

Wong, Man-Ling; An, Dongshan; Caffrey, Sean M.; Soh, Jung; Dong, Xiaoli; Sensen, Christoph W.; Oldenburg, Thomas B. P.; Larter, Steve R.

2015-01-01

Oil sands are surface exposed in river valley outcrops in northeastern Alberta, where flat slabs (tablets) of weathered, bitumen-saturated sandstone can be retrieved from outcrop cliffs or from riverbeds. Although the average yearly surface temperature of this region is low (0.7°C), we found that the temperatures of the exposed surfaces of outcrop cliffs reached 55 to 60°C on sunny summer days, with daily maxima being 27 to 31°C. Analysis of the cooccurrence of taxa derived from pyrosequencing of 16S/18S rRNA genes indicated that an aerobic microbial network of fungi and hydrocarbon-, methane-, or acetate-oxidizing heterotrophic bacteria was present in all cliff tablets. Metagenomic analyses indicated an elevated presence of fungal cytochrome P450 monooxygenases in these samples. This network was distinct from the heterotrophic community found in riverbeds, which included fewer fungi. A subset of cliff tablets had a network of anaerobic and/or thermophilic taxa, including methanogens, Firmicutes, and Thermotogae, in the center. Long-term aerobic incubation of outcrop samples at 55°C gave a thermophilic microbial community. Analysis of residual bitumen with a Fourier transform ion cyclotron resonance mass spectrometer indicated that aerobic degradation proceeded at 55°C but not at 4°C. Little anaerobic degradation was observed. These results indicate that bitumen degradation on outcrop surfaces is a largely aerobic process with a minor anaerobic contribution and is catalyzed by a consortium of bacteria and fungi. Bitumen degradation is stimulated by periodic high temperatures on outcrop cliffs, which cause significant decreases in bitumen viscosity. PMID:26209669

What Physical Fitness Component Is Most Closely Associated With Adolescents' Blood Pressure?

PubMed

Nunes, Heloyse E G; Alves, Carlos A S; Gonçalves, Eliane C A; Silva, Diego A S

2017-12-01

This study aimed to determine which of four selected physical fitness variables, would be most associated with blood pressure changes (systolic and diastolic) in a large sample of adolescents. This was a descriptive and cross-sectional, epidemiological study of 1,117 adolescents aged 14-19 years from southern Brazil. Systolic and diastolic blood pressure were measured by a digital pressure device, and the selected physical fitness variables were body composition (body mass index), flexibility (sit-and-reach test), muscle strength/resistance (manual dynamometer), and aerobic fitness (Modified Canadian Aerobic Fitness Test). Simple and multiple linear regression analyses revealed that aerobic fitness and muscle strength/resistance best explained variations in systolic blood pressure for boys (17.3% and 7.4% of variance) and girls (7.4% of variance). Aerobic fitness, body composition, and muscle strength/resistance are all important indicators of blood pressure control, but aerobic fitness was a stronger predictor of systolic blood pressure in boys and of diastolic blood pressure in both sexes.

Temperature effects on the aerobic metabolism of glycogen-accumulating organisms.

PubMed

Lopez-Vazquez, Carlos M; Song, Young-Il; Hooijmans, Christine M; Brdjanovic, Damir; Moussa, Moustafa S; Gijzen, Huub J; van Loosdrecht, Mark C M

2008-10-01

Short-term temperature effects on the aerobic metabolism of glycogen-accumulating organisms (GAO) were investigated within a temperature range from 10 to 40 degrees C. Candidatus Competibacter Phosphatis, known GAO, were the dominant microorganisms in the enriched culture comprising 93 +/- 1% of total bacterial population as indicated by fluorescence in situ hybridization (FISH) analysis. Between 10 and 30 degrees C, the aerobic stoichiometry of GAO was insensitive to temperature changes. Around 30 degrees C, the optimal temperature for most of the aerobic kinetic rates was found. At temperatures higher than 30 degrees C, a decrease on the aerobic stoichiometric yields combined with an increase on the aerobic maintenance requirements were observed. An optimal overall temperature for both anaerobic and aerobic metabolisms of GAO appears to be found around 30 degrees C. Furthermore, within a temperature range (10-30 degrees C) that covers the operating temperature range of most of domestic wastewater treatment systems, GAOs aerobic kinetic rates exhibited a medium degree of dependency on temperature (theta = 1.046-1.090) comparable to that of phosphorus accumulating organisms (PAO). We conclude that GAO do not have metabolic advantages over PAO concerning the effects of temperature on their aerobic metabolism, and competitive advantages are due to anaerobic processes.

Meta-analysis: aerobic exercise for the treatment of anxiety disorders.

PubMed

Bartley, Christine A; Hay, Madeleine; Bloch, Michael H

2013-08-01

This meta-analysis investigates the efficacy of exercise as a treatment for DSM-IV diagnosed anxiety disorders. We searched PubMED and PsycINFO for randomized, controlled trials comparing the anxiolytic effects of aerobic exercise to other treatment conditions for DSM-IV defined anxiety disorders. Seven trials were included in the final analysis, totaling 407 subjects. The control conditions included non-aerobic exercise, waitlist/placebo, cognitive-behavioral therapy, psychoeducation and meditation. A fixed-effects model was used to calculate the standardized mean difference of change in anxiety rating scale scores of aerobic exercise compared to control conditions. Subgroup analyses were performed to examine the effects of (1) comparison condition; (2) whether comparison condition controlled for time spent exercising and (3) diagnostic indication. Aerobic exercise demonstrated no significant effect for the treatment of anxiety disorders (SMD=0.02 (95%CI: -0.20-0.24), z = 0.2, p = 0.85). There was significant heterogeneity between trials (χ(2) test for heterogeneity = 22.7, df = 6, p = 0.001). The reported effect size of aerobic exercise was highly influenced by the type of control condition. Trials utilizing waitlist/placebo controls and trials that did not control for exercise time reported large effects of aerobic exercise while other trials report no effect of aerobic exercise. Current evidence does not support the use of aerobic exercise as an effective treatment for anxiety disorders as compared to the control conditions. This remains true when controlling for length of exercise sessions and type of anxiety disorder. Future studies evaluating the efficacy of aerobic exercise should employ larger sample sizes and utilize comparison interventions that control for exercise time. Copyright © 2013. Published by Elsevier Inc.

The high aerobic capacity of a small, marsupial rat-kangaroo (Bettongia penicillata) is matched by the mitochondrial and capillary morphology of its skeletal muscles.

PubMed

Webster, Koa N; Dawson, Terence J

2012-09-15

We examined the structure-function relationships that underlie the aerobic capacities of marsupial mammals that hop. Marsupials have relatively low basal metabolic rates (BMR) and historically were seen as 'low energy' mammals. However, the red kangaroo, Macropus rufus (family Macropodidae), has aerobic capacities equivalent to athletic placentals. It has an extreme aerobic scope (fAS) and its large locomotor muscles feature high mitochondrial and capillary volumes. M. rufus belongs to a modern group of kangaroos and its high fAS is not general for marsupials. However, other hopping marsupials may have elevated aerobic capacities. Bettongia penicillata, a rat-kangaroo (family Potoroidae), is a small (1 kg), active hopper whose fAS is somewhat elevated. We examined the oxygen delivery system in its muscles to ascertain links with hopping. An elevated fAS of 23 provided a relatively high maximal aerobic oxygen consumption ( ) in B. penicillata; associated with this is a skeletal muscle mass of 44% of body mass. Ten muscles were sampled to estimate the total mitochondrial and capillary volume of the locomotor muscles. Values in B. penicillata were similar to those in M. rufus and in athletic placentals. This small hopper had high muscle mitochondrial volume densities (7.1-11.9%) and both a large total capillary volume (6 ml kg(-1) body mass) and total capillary erythrocyte volume (3.2 ml kg(-1)). Apparently, a considerable aerobic capacity is required to achieve the benefits of the extended stride in fast hopping. Of note, the ratio of to total muscle mitochondrial volume in B. penicillata was 4.9 ml O(2) min(-1) ml(-1). Similar values occur in M. rufus and also placental mammals generally, not only athletic species. If such relationships occur in other marsupials, a fundamental structure-function relationship for oxygen delivery to muscles likely originated with or before the earliest mammals.

Association Between Sarcopenia-Related Phenotypes and Aerobic Capacity Indexes of Older Women

PubMed Central

de Oliveira, Ricardo Jacó; Bottaro, Martim; Motta, Antonio Marco; Pitanga, Francisco; Guido, Marcelo; Leite, Tailce Kaley Moura; Bezerra, Lídia Mara Aguiar; Lima, Ricardo Moreno

2009-01-01

The purpose of the present study was to examine the association between fat-free mass (FFM), quadriceps strength and sarcopenia with aerobic fitness indexes of elderly women. A total of 189 volunteers (66.7 ± 5.46 years) underwent aerobic capacity measurement through a symptom-limited cardiopulmonary exercise test to determine their individual ventilatory thresholds (VT) and peak oxygen uptake (VO2 peak). Quadriceps muscle strength was assessed using an isokinetic dynamometer. Also, dual energy X-ray absorptiometry was used to assess FFM and cutoff values were used to classify subjects as sarcopenic or nonsarcopenic. Correlations, student t-test and analysis of variance were used to examine the data. Both FFM and quadriceps strength variables were positively and significantly correlated with the measured aerobic capacity indexes. These results were observed for peak exercise as well as for ventilatory thresholds. Individuals classified as sarcopenic presented significantly lower muscle strength and (VO2 peak) when compared to nonsarcopenic. It can be concluded that FFM and quadriceps strength are significantly related to aerobic capacity indexes in older women, and that besides presenting lower quadriceps strength, women classified as sarcopenic have lower peak oxygen consumption. Taken together, the present results indicate that both FFM and strength play a role in the age-related decline of aerobic capacity. Key points Maximal aerobic capacity, generally expressed as peak oxygen consumption (VO2 peak), declines with advancing age and this process is associated with an increased risk for cardiovascular diseases. Also, the aging process is associated with a progressive loss of muscle mass and strength and this phenomenon has been referred to as Sarcopenia. Sarcopenia has been described in both elderly men and women and has been linked to multiple negative clinical outcomes. The present study provide evidence that muscle-related phenotypes are associated with aerobic capacity of older individuals, thus suggesting that sarcopenia explains in part the decline in aerobic fitness observed with advancing age. PMID:24149995

Microbiological hazard analysis of ready-to-eat meats processed at a food plant in Trinidad, West Indies.

PubMed

Syne, Stacey-Marie; Ramsubhag, Adash; Adesiyun, Abiodun A

2013-01-01

A bacteriological assessment of the environment and food products at different stages of processing was conducted during the manufacture of ready-to-eat (RTE) chicken franks, chicken bologna and bacon at a large meat processing plant in Trinidad, West Indies. Samples of air, surfaces (swabs), raw materials, and in-process and finished food products were collected during two separate visits for each product type and subjected to qualitative or quantitative analysis for bacterial zoonotic pathogens and fecal indicator organisms. Staphylococcus aureus was the most common pathogen detected in pre-cooked products (mean counts = 0.66, 1.98, and 1.95 log10CFU/g for franks, bologna, and bacon, respectively). This pathogen was also found in unacceptable levels in 4 (16.7%) of 24 post-cooked samples. Fifty percent (10 of 20) of pre-cooked mixtures of bacon and bologna were contaminated with Listeria spp., including four with L. monocytogenes. Pre-cooked mixtures of franks and bologna also contained E. coli (35 and 0.72 log10 CFU/g, respectively) while 5 (12.5%) of 40 pre-cooked mixtures of chicken franks had Salmonella spp. Aerobic bacteria exceeded acceptable international standards in 46 (82.1%) of 56 pre-cooked and 6 (16.7%) of 36 post-cooked samples. Both pre-and post-cooking air and surfaces had relatively high levels of aerobic bacteria, Staphylococcus aureus and coliforms, including equipment and gloves of employees. A drastic decrease in aerobic counts and Staphylococcus aureus levels following heat treatment and subsequent increase in counts of these bacteria are suggestive of post-cooking contamination. A relatively high level of risk exists for microbial contamination of RTE meats at the food plant investigated and there is a need for enhancing the quality assurance programs to ensure the safety of consumers of products manufactured at this plant.

Microbiological hazard analysis of ready-to-eat meats processed at a food plant in Trinidad, West Indies

PubMed Central

Syne, Stacey-Marie; Ramsubhag, Adash; Adesiyun, Abiodun A.

2013-01-01

Background A bacteriological assessment of the environment and food products at different stages of processing was conducted during the manufacture of ready-to-eat (RTE) chicken franks, chicken bologna and bacon at a large meat processing plant in Trinidad, West Indies. Methods Samples of air, surfaces (swabs), raw materials, and in-process and finished food products were collected during two separate visits for each product type and subjected to qualitative or quantitative analysis for bacterial zoonotic pathogens and fecal indicator organisms. Results Staphylococcus aureus was the most common pathogen detected in pre-cooked products (mean counts = 0.66, 1.98, and 1.95 log10CFU/g for franks, bologna, and bacon, respectively). This pathogen was also found in unacceptable levels in 4 (16.7%) of 24 post-cooked samples. Fifty percent (10 of 20) of pre-cooked mixtures of bacon and bologna were contaminated with Listeria spp., including four with L. monocytogenes. Pre-cooked mixtures of franks and bologna also contained E. coli (35 and 0.72 log10 CFU/g, respectively) while 5 (12.5%) of 40 pre-cooked mixtures of chicken franks had Salmonella spp. Aerobic bacteria exceeded acceptable international standards in 46 (82.1%) of 56 pre-cooked and 6 (16.7%) of 36 post-cooked samples. Both pre-and post-cooking air and surfaces had relatively high levels of aerobic bacteria, Staphylococcus aureus and coliforms, including equipment and gloves of employees. A drastic decrease in aerobic counts and Staphylococcus aureus levels following heat treatment and subsequent increase in counts of these bacteria are suggestive of post-cooking contamination. Conclusion A relatively high level of risk exists for microbial contamination of RTE meats at the food plant investigated and there is a need for enhancing the quality assurance programs to ensure the safety of consumers of products manufactured at this plant. PMID:23878681

Effects of composting process on the dissipation of extractable sulfonamides in swine manure.

PubMed

Liu, Bei; Li, Yanxia; Zhang, Xuelian; Feng, Chenghong; Gao, Min; Shen, Qiu

2015-01-01

Effects of composting on the fate of sulfonamides (SAs) in the manure-straw mixture were explored through a simulation of aerobic composting process. Additionally, factors of temperature and coexistence of heavy metal Cu that might influence the removal efficiency were particularly investigated. As shown in the results, the extractable SAs dissipated rapidly during the composting process. The coexistence of Cu in the composting process might have delayed the decline of SAs, but the drugs could still be completely removed by the end of the composting. In contrast to the thermophilic aerobic composting, extractable SAs in air-temperature-placed mixture dissipated much slower and 1.12-1.56mg/kg could be detected after 35days of incubation. The results confirmed that temperature could influence the dissipation of SAs, which was identified as a more important factor than Cu-coexistence. Hence, thermophilic aerobic composting is an effective process to eliminate VAs before manure land application. Copyright © 2014 Elsevier Ltd. All rights reserved.

Impact of intermittent aerations on leachate quality and greenhouse gas reduction in the aerobic-anaerobic landfill method.

PubMed

Nag, Mitali; Shimaoka, Takayuki; Komiya, Teppei

2016-09-01

The aerobic-anaerobic landfill method (AALM) is a novel approach in solid waste management that could shorten the landfill post-closure period and minimize the environmental loads. In this study, the aerobic-anaerobic landfill method was evaluated by using intermittent aeration. In addition, the nitrification-denitrification process was assessed as a means of reducing the emission of greenhouse gases (GHGs) and improving the leachate quality during the degradation of the organic solid waste. The leachate quality and the gas composition in each of the reactors were measured during the experimental period (408days). The aeration process entailed the injection of air into plexiglass cylinders (200cm height×10 cm diameter), filled with fresh organic solid waste collected from a composting plant. Different aeration routines were applied, namely, continuous aeration (aerobic reactor A), aeration for three days/week (aerobic-anaerobic reactor B), aeration for 6h/day (aerobic-anaerobic reactor C), and no aeration (non-aerated reactor D). It was found that aerobic reactor A produced the best results in terms of reduction of GHGs and improvement of the leachate quality. The aerobic-anaerobic reactor C was found to be more effective than reactor B in respect of both the emission of GHGs and the leachate quality; moreover, compared with aerobic reactor A, energy costs were reduced by operating this reactor. The transition period phenomenon was investigated during an intensive seven-day experiment conducted on the discharged leachate obtained from aerobic-anaerobic reactors B and C. The experiment concerned the differences in the composition of the gas during the aeration and the non-aeration periods. It was found that the transition period between the aeration and non-aeration cycles, which followed the simultaneous nitrification-denitrification had a considerable effect on the leachate quality of both the reactors. The results indicated that AALM has the potential to reduce leachate pollutants and the emission of GHGs. Furthermore, the occurrence of simultaneous nitrification-denitrification presents the prospect that intermittent aeration could reduce landfill aftercare and energy costs. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Phosphorus removal characteristics by aerobic granules in normal molasses wastewater after anaerobic treatment].

PubMed

Wang, Shuo; Yu, Shui-Li; Shi, Wen-Xin; Bao, Rui-Ling; Yi, Xue-Song; Li, Jian-Zheng

2012-04-01

COD decreased obviously in normal molasses wastewater after anaerobic treatment, however, concentrations of nitrogen and phosphorus were still higher in the effluent which seriously damaged the ecological balance. In this study, aerobic granules cultivated in sequencing batch airlift reactor (SBAR) were carried out for treating the effluent; phosphorus removal processes and characteristics were discussed as well. The mean diameter of aerobic granules cultivated by multiple carbon sources (acetate, propionate and butyrate) was 1.7 mm. The average phosphorus removal efficiency was 90.9% and the level of phosphorus in effluent was only 1.3 mg x L(-1); TP released per COD consumed was 0.571 and the specific rate of TP released was 5.73 mg x (g x h)(-1). NO3(-) -N usage of phosphorus accumulating organisms (PAOs) improved during denitrifying process because the concentration of propionate and butyrate increased in multiple carbon sources which means the phosphorus uptake efficiency increased when per NO3(-) -N consumed. Phosphorus content represented a stronger correlation with magnesium, calcium and ferrum contents in aerobic granules and their extracellular polymeric substances (EPS), the phosphorus adsorption by EPS could enhance phosphorus removal. 61.9% of phosphorus accumulating organisms were denitrifying phosphorus accumulating organisms in aerobic granules and TP uptake per NO3(-) -N consumed was 1.14 which was higher than that of aerobic granules only cultivated by acetate.

Effectiveness of photobiomodulation therapy and aerobic exercise training on articular cartilage in an experimental model of osteoarthritis in rats

NASA Astrophysics Data System (ADS)

Assis, Lívia; Tim, Carla; Martignago, Cintia; Gonçalves, Silma Rodrigues; Renno, Ana Claudia Muniz

2018-02-01

Osteoarthritis (OA) is the most common disease of the knee joints in adults throughout the world. Photobiomodulation (PBM) and physical exercise have been studied for clinical treatment of OA, even though the effects and action mechanisms have not yet been clarified. The aim of this study was to evaluate the effects of PBM and aerobic exercise (associated or not) on degenerative modifications and inflammatory mediators in articular cartilage using an experimental model of knee OA. Forty male Wistar rats were randomly divided into 4 groups: OA animals without treatment (OAC); OA plus aerobic exercise training (OAT); OA animals plus PBM treatment (OAP); OA plus aerobic exercise training and PBM treatment (OATP). The exercise training (treadmill; 16m/min; 50 min/day) and the PBM treatment started 4 weeks after the surgery, 3 days/week for 8 weeks. The results showed that all treated groups showed a lower degenerative process measured by OARSI system and higher thickness values. Moreover, aerobic exercise and PBM (associated or not) decreased iNOS expression and increased IL-10 expression in OAT and OATL compared to OAC. Furthermore, a lower TGF-β expression was observed in associated therapies. These results suggest that PBM and aerobic exercise training were effective in modulating inflammatory process and preventing cartilage degeneration in knees in OA rats.

Relationship between aerobic bacteria, salmonellae and Campylobacter on broiler carcasses.

PubMed

Cason, J A; Bailey, J S; Stern, N J; Whittemore, A D; Cox, N A

1997-07-01

Broiler carcasses were removed from commercial processing lines immediately after defeathering, before chilling, and after chilling to determine whether any relationship exists between aerobic bacteria and the human enteropathogens salmonellae and Campylobacter. In two experiments, a whole carcass rinse procedure was used to sample 30 carcasses after defeathering, 90 carcasses before chilling, and 90 carcasses after chilling, for a total of 210 different carcasses. Aerobic bacteria and Campylobacter spp. were enumerated and the incidence of salmonellae was determined. Salmonellae and Campylobacter incidences were 20 and 94%, respectively, for all carcasses sampled. After picking, neither salmonellae-positive nor Campylobacter-positive carcasses had mean aerobic most probable number (MPN) values that were different from carcasses negative for those organisms. Immediately before chilling, aerobic and Campylobacter counts were 7.12 and 5.33 log10 cfu per carcass, respectively. Immersion chilling reduced aerobic counts by approximately 1.8 log and Campylobacter by 1.5 log, with no change in salmonellae-positive carcasses. There was no difference in aerobic or Campylobacter counts between carcasses that were positive or negative for salmonellae at any of the sampling locations, nor was any correlation found between levels of aerobic organisms and Campylobacter. Carcasses with aerobic counts above the mean or more than one standard deviation above the mean also failed to show any correlation. Discriminant analysis indicated error rates as high as 50% when numbers of aerobic bacteria were used to predict incidence of salmonellae or Campylobacter on individual carcasses. Aerobic bacteria are not suitable as index organisms for salmonellae or Campylobacter on broiler carcasses.

Inhibiting aerobic glycolysis suppresses renal interstitial fibroblast activation and renal fibrosis.

PubMed

Ding, Hao; Jiang, Lei; Xu, Jing; Bai, Feng; Zhou, Yang; Yuan, Qi; Luo, Jing; Zen, Ke; Yang, Junwei

2017-09-01

Chronic kidney diseases generally lead to renal fibrosis. Despite great progress having been made in identifying molecular mediators of fibrosis, the mechanism that governs renal fibrosis remains unclear, and so far no effective therapeutic antifibrosis strategy is available. Here we demonstrated that a switch of metabolism from oxidative phosphorylation to aerobic glycolysis (Warburg effect) in renal fibroblasts was the primary feature of fibroblast activation during renal fibrosis and that suppressing renal fibroblast aerobic glycolysis could significantly reduce renal fibrosis. Both gene and protein assay showed that the expression of glycolysis enzymes was upregulated in mouse kidneys with unilateral ureter obstruction (UUO) surgery or in transforming growth factor-β1 (TGF-β1)-treated renal interstitial fibroblasts. Aerobic glycolysis flux, indicated by glucose uptake and lactate production, was increased in mouse kidney with UUO nephropathy or TGF-β1-treated renal interstitial fibroblasts and positively correlated with fibrosis process. In line with this, we found that increasing aerobic glycolysis can remarkably induce myofibroblast activation while aerobic glycolysis inhibitors shikonin and 2-deoxyglucose attenuate UUO-induced mouse renal fibrosis and TGF-β1-stimulated myofibroblast activation. Furthermore, mechanistic study indicated that shikonin inhibits renal aerobic glycolysis via reducing phosphorylation of pyruvate kinase type M2, a rate-limiting glycolytic enzyme associated with cell reliance on aerobic glycolysis. In conclusion, our findings demonstrate the critical role of aerobic glycolysis in renal fibrosis and support treatment with aerobic glycolysis inhibitors as a potential antifibrotic strategy. Copyright © 2017 the American Physiological Society.

Sequential anaerobic/aerobic digestion for enhanced sludge stabilization: comparison of the process performance for mixed and waste sludge [corrected].

PubMed

Tomei, M Concetta; Carozza, Nicola Antonello

2015-05-01

Sequential anaerobic-aerobic digestion has been demonstrated as a promising alternative for enhanced sludge stabilization. In this paper, a feasibility study of the sequential digestion applied to real waste activated sludge (WAS) and mixed sludge is presented. Process performance is evaluated in terms of total solid (TS) and volatile solid (VS) removal, biogas production, and dewaterability trend in the anaerobic and double-stage digested sludge. In the proposed digestion lay out, the aerobic stage was operated with intermittent aeration to reduce the nitrogen load recycled to the wastewater treatment plant (WWTP). Experimental results showed a very good performance of the sequential digestion process for both waste and mixed sludge, even if, given its better digestibility, higher efficiencies are observed for mixed sludge. VS removal efficiencies in the anaerobic stage were 48 and 50% for waste and mixed sludge, respectively, while a significant additional improvement of the VS removal of 25% for WAS and 45% for mixed sludge has been obtained in the aerobic stage. The post-aerobic stage, operated with intermittent aeration, was also efficient in nitrogen removal, providing a significant decrease of the nitrogen content in the supernatant: nitrification efficiencies of 90 and 97% and denitrification efficiencies of 62 and 70% have been obtained for secondary and mixed sludges, respectively. A positive effect due to the aerobic stage was also observed on the sludge dewaterability in both cases. Biogas production, expressed as Nm(3)/(kgVSdestroyed), was 0.54 for waste and 0.82 for mixed sludge and is in the range of values reported in the literature in spite of the low anaerobic sludge retention time of 15 days.

Acclimation of aerobic-activated sludge degrading benzene derivatives and co-metabolic degradation activities of trichloroethylene by benzene derivative-grown aerobic sludge.

PubMed

Wang, Shizong; Yang, Qi; Bai, Zhiyong; Wang, Shidong; Wang, Yeyao; Nowak, Karolina M

2015-01-01

The acclimation of aerobic-activated sludge for degradation of benzene derivatives was investigated in batch experiments. Phenol, benzoic acid, toluene, aniline and chlorobenzene were concurrently added to five different bioreactors which contained the aerobic-activated sludge. After the acclimation process ended, the acclimated phenol-, benzoic acid-, toluene-, aniline- and chlorobenzene-grown aerobic-activated sludge were used to explore the co-metabolic degradation activities of trichloroethylene (TCE). Monod equation was employed to simulate the kinetics of co-metabolic degradation of TCE by benzene derivative-grown sludge. At the end of experiments, the mixed microbial communities grown under different conditions were identified. The results showed that the acclimation periods of microorganisms for different benzene derivatives varied. The maximum degradation rates of TCE for phenol-, benzoic acid-, toluene-, aniline- and chlorobenzene-grown aerobic sludge were 0.020, 0.017, 0.016, 0.0089 and 0.0047 mg g SS(-1) h(-1), respectively. The kinetic of TCE degradation in the absence of benzene derivative followed Monod equation well. Also, eight phyla were observed in the acclimated benzene derivative-grown aerobic sludge. Each of benzene derivative-grown aerobic sludge had different microbial community composition. This study can hopefully add new knowledge to the area of TCE co-metabolic by mixed microbial communities, and further the understanding on the function and applicability of aerobic-activated sludge.

MONITORING POLYCHLORINATED BIPHENYLS (PCBS) BIODEGRADATION USING CONTINUOUS-FLOW ISOTOPE RATIO MASS SPECTROMETRY

EPA Science Inventory

Research has shown that polychlorinated biphenyls (PCBs) in some cases can be removed from the environment by biodegradation. Aerobic and anaerobic biological processes have been determined in previous research to be capable of degrading PCBs. During the aerobic and anaerobic d...

Composting: Fast 2.

ERIC Educational Resources Information Center

Brantley, L. Reed, Sr.; Demanche, Edna L.; Klemm, E. Barbara; Kyselka, Will; Phillips, Edwin A.; Pottenger, Francis M.; Yamamoto, Karen N.; Young, Donald B.

Composting is a way of using organic wastes from yards and kitchens to help plants grow. This book discusses how composting happens in nature, the classification of composting methods, and their characteristics. Examples of containers for aerobic/anaerobic decomposition are introduced along with sample activities. The process of aerobic/anaerobic…

Aerobic Exercises for Cognition Rehabilitation following Stroke: A Systematic Review.

PubMed

Zheng, Guohua; Zhou, Wenji; Xia, Rui; Tao, Jing; Chen, Lidian

2016-11-01

Cognitive impairments are highly prevalent in stroke survivors and can substantially affect their physical rehabilitation and quality of life. The management of these impairments currently remains limited, but increasing studies reported the effect of aerobic exercise on cognitive performance in patients suffering from stroke. The purpose of this review was to assess the effects of aerobic exercise on cognitive function following stroke. Seven electronic databases (China National Knowledge Infrastructure [CNKI], Chinese Science and Technology Periodical Database [VIP], Wanfang, China Biology Medicine disc [CBM], Science Citation Index [SCI], EMBASE, and PubMed) were searched from their inception to May 31, 2015, for the effects of aerobic exercise on cognitive ability compared to usual physical activity in stroke survivors. RevMan V5.3 (The Nordic Cochrane Centre) was used to analyze the data and to evaluate the methodological quality of the included studies. Ten eligible studies including 394 participants were identified. Six studies showed that aerobic exercise significantly improved global cognitive ability in stroke survivors. Four studies reported aerobic exercise to be beneficial in improving memory, but only one showed statistical significance. Two studies investigated the effects of aerobic exercise on attention, and one showed a significant improvement. One study reported a significant benefit of aerobic exercise on visuospatial ability in stroke survivors. No adverse events were reported in the included studies. Aerobic exercise may have a positive effect on improving global cognitive ability and a potential benefit on memory, attention, and the visuospatial domain of cognition in stroke survivors. However, further large, rigorously designed trials are needed to confirm these findings. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Mechanisms of floc destruction during anaerobic and aerobic digestion and the effect on conditioning and dewatering of biosolids.

PubMed

Novak, John T; Sadler, Mary E; Murthy, Sudhir N

2003-07-01

Laboratory anaerobic and aerobic digestion studies were conducted using waste activated sludges from two municipal wastewater treatment plants in order to gain insight into the mechanisms of floc destruction that account for changes in sludge conditioning and dewatering properties when sludges undergo anaerobic and aerobic digestion. Batch digestion studies were conducted at 20 degrees C and the dewatering properties, solution biopolymer concentration and conditioning dose requirements measured. The data indicated that release of biopolymer from sludges occurred under both anaerobic and aerobic conditions but that the release was much greater under anaerobic conditions. In particular, the release of protein into solution was 4-5 times higher under anaerobic than under aerobic conditions. Both the dewatering rate, as characterized by the specific resistance to filtration and the amount of polymer conditioning chemicals required was found to depend directly on the amount of biopolymer (protein + polysaccharide) in solution. Little difference in dewatering properties and conditioning doses was seen between the two activated sludges from different plants. Differences in the cations released between anaerobic and aerobic digestion suggest that the digestion mechanisms differ for the two types of processes. Enzyme activity data showed that during aerobic digestion, polysaccharide degradation activity decreased to near zero and this was consistent with the accumulation of polysaccharides in aerobic digesters.

Combined mesophilic anaerobic and thermophilic aerobic digestion process: effect on sludge degradation and variation of sludge property.

PubMed

Cheng, Jiehong; Ji, Yuehong; Kong, Feng; Chen, Xian

2013-12-01

One-stage autothermal thermophilic aerobic digestion (ATAD) is effective for the reduction of volatile solids (VSs) and pathogen in sewage sludges. A novel process of combining mesophilic (<35 °C) anaerobic digestion with a thermophilic (55 °C) aerobic digestion process (AN/TAD) occurred in a one-stage digester, which was designed for aeration energy savings. The efficiency of sludge degradation and variation of sludge properties by batch experiments were evaluated for the AN/TAD digester with an effective volume of 23 L for 30 days compared with conventional thermophilic aerobic digestion (TAD). The AN/TAD system can efficiently achieve sludge stabilization on the 16th day with a VS removal rate of 38.1 %. The AN/TAD system was operated at lower ORP values in a digestion period with higher contents of total organic compounds, volatile fatty acids, protein, and polysaccharide in the soluble phase than those of the TAD system, which can rapidly decreased and had low values in the late period of digestion for the AN/TAD system. In the AN/TAD system, intracellular substances had lysis because of initial hydrolytic acidification.

Effects of aerobic and anaerobic biological processes on leaching of heavy metals from soil amended with sewage sludge compost.

PubMed

Fang, Wen; Wei, Yonghong; Liu, Jianguo; Kosson, David S; van der Sloot, Hans A; Zhang, Peng

2016-12-01

The risk from leaching of heavy metals is a major factor hindering land application of sewage sludge compost (SSC). Understanding the change in heavy metal leaching resulting from soil biological processes provides important information for assessing long-term behavior of heavy metals in the compost amended soil. In this paper, 180days aerobic incubation and 240days anaerobic incubation were conducted to investigate the effects of the aerobic and anaerobic biological processes on heavy metal leaching from soil amended with SSC, combined with chemical speciation modeling. Results showed that leaching concentrations of heavy metals at natural pH were similar before and after biological process. However, the major processes controlling heavy metals were influenced by the decrease of DOC with organic matter mineralization during biological processes. Mineralization of organic matter lowered the contribution of DOC-complexation to Ni and Zn leaching. Besides, the reducing condition produced by biological processes, particularly by the anaerobic biological process, resulted in the loss of sorption sites for As on Fe hydroxide, which increased the potential risk of As release at alkaline pH. Copyright © 2016 Elsevier Ltd. All rights reserved.

Autoheated thermophilic aerobic digestion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deeny, K.; Hahn, H.; Leonhard, D.

1991-10-01

Autothermal thermophilic aerobic digestion (ATAD) is first and foremost a digestion process, the primary purpose of which is to decompose a portion of the waste organic solids generated from wastewater treatment. As a result of the high operating temperature, digestion is expected to occur within a short time period (6 days) and accomplish a high degree of pathogen reduction. ATAD systems are two-stage aerobic digestion processes that operate under thermophilic temperature conditions (40 to 80C) without supplemental heat. Like composting, the systems rely on the conservation of heat released during digestion itself to attain and sustain the desired operating temperature.more » Typical ATAD systems operate at 55C and may reach temperatures of 60 to 65C in the second-stage reactor. Perhaps because of the high operating temperature, this process has been referred to as Liquid Composting.' Major advantages associated with thermophilic operation include high biological reaction rates and a substantial degree of pathogen reduction.« less

Aeration control of thermophilic aerobic digestion using fluorescence monitoring.

PubMed

Kim, Young-Kee; Oh, Byung-Keun

2009-01-01

The thermophilic aerobic digestion (TAD) process is recognized as an effective method for rapid waste activated sludge (WAS) degradation and the deactivation of pathogenic microorganisms. Yet, high energy costs due to heating and aeration have limited the commercialization of economical TAD processes. Previous research on autothermal thermophilic aerobic digestion (ATAD) has already reduced the heating cost. However, only a few studies have focused on reducing the aeration cost. Therefore, this study applied a two-step aeration control strategy to a fill-and-draw mode semicontinuous TAD process. The NADH-dependent fluorescence was monitored throughout the TAD experiment, and the aeration rate shifted according to the fluorescence intensity. As a result, the simple two-step aeration control operation achieved a 20.3% reduction in the total aeration, while maintaining an effective and stable operation. It is also expected that more savings can be achieved with a further reduction of the lower aeration rate or multisegmentation of the aeration rate.

AIRBORNE MICROORGANISMS IN BROILER PROCESSING PLANTS.

PubMed

KOTULA, A W; KINNER, J A

1964-05-01

Concentrations of total aerobic bacteria, molds, yeasts, coliforms, enterococci, and psychrophiles were determined in the air of two poultry processing plants with Andersen samplers and a mobile power supply. Total aerobic bacterial counts were highest in the dressing room, with diminishing numbers in the shackling, eviscerating, and holding rooms, when sampling was carried out during plant operation. The average counts per ft(3) of air in these four rooms were 2,200; 560; 230; and 62, respectively. (Each value is the average of 36 observations.) The number of organisms increased in the shackling and dressing rooms once processing was begun. Average total aerobic bacterial counts increased from 70 to 870 to 3,000 in the shackling room and from 310 to 4,900 to 7,000 in the dressing room when sampling was carried out at 5:00 am (before plant operations), 9:00 am, and 2:00 pm, respectively. (Each value is the mean of 12 observations.) Airborne molds might originate from a source other than the poultry being processed.

Airborne Microorganisms in Broiler Processing Plants

PubMed Central

Kotula, Anthony W.; Kinner, Jack A.

1964-01-01

Concentrations of total aerobic bacteria, molds, yeasts, coliforms, enterococci, and psychrophiles were determined in the air of two poultry processing plants with Andersen samplers and a mobile power supply. Total aerobic bacterial counts were highest in the dressing room, with diminishing numbers in the shackling, eviscerating, and holding rooms, when sampling was carried out during plant operation. The average counts per ft3 of air in these four rooms were 2,200; 560; 230; and 62, respectively. (Each value is the average of 36 observations.) The number of organisms increased in the shackling and dressing rooms once processing was begun. Average total aerobic bacterial counts increased from 70 to 870 to 3,000 in the shackling room and from 310 to 4,900 to 7,000 in the dressing room when sampling was carried out at 5:00 am (before plant operations), 9:00 am, and 2:00 pm, respectively. (Each value is the mean of 12 observations.) Airborne molds might originate from a source other than the poultry being processed. Images FIG. 3 PMID:14170951

Characterization, modeling and application of aerobic granular sludge for wastewater treatment.

PubMed

Liu, Xian-Wei; Yu, Han-Qing; Ni, Bing-Jie; Sheng, Guo-Ping

2009-01-01

Recently extensive studies have been carried out to cultivate aerobic granular sludge worldwide, including in China. Aerobic granules, compared with conventional activated sludge flocs, are well known for their regular, dense, and strong microbial structure, good settling ability, high biomass retention, and great ability to withstand shock loadings. Studies have shown that the aerobic granules could be applied for the treatment of low- or high-strength wastewaters, simultaneous removal of organic carbon, nitrogen and phosphorus, and decomposition of toxic wastewaters. Thus, this new form of activate sludge, like anaerobic granular sludge, could be employed for the treatment of municipal and industrial wastewaters in near future. This chapter attempts to provide an up-to-date review on the definition, cultivation, characterization, modeling and application of aerobic granular sludge for biological wastewater treatment. This review outlines some important discoveries with regard to the factors affecting the formation of aerobic granular sludge, their physicochemical characteristics, as well as their microbial structure and diversity. It also summarizes the modeling of aerobic granule formation. Finally, this chapter highlights the applications of aerobic granulation technology in the biological wastewater treatment. It is concluded that the knowledge regarding aerobic granular sludge is far from complete. Although previous studies in this field have undoubtedly improved our understanding on aerobic granular sludge, it is clear that much remains to be learned about the process and that many unanswered questions still remain. One of the challenges appears to be the integration of the existing and growing scientific knowledge base with the observations and applications in practice, which this paper hopes to partially achieve.

Characterization, Modeling and Application of Aerobic Granular Sludge for Wastewater Treatment

NASA Astrophysics Data System (ADS)

Liu, Xian-Wei; Yu, Han-Qing; Ni, Bing-Jie; Sheng, Guo-Ping

Recently extensive studies have been carried out to cultivate aerobic granular sludge worldwide, including in China. Aerobic granules, compared with conventional activated sludge flocs, are well known for their regular, dense, and strong microbial structure, good settling ability, high biomass retention, and great ability to withstand shock loadings. Studies have shown that the aerobic granules could be applied for the treatment of low- or high-strength wastewaters, simultaneous removal of organic carbon, nitrogen and phosphorus, and decomposition of toxic wastewaters. Thus, this new form of activate sludge, like anaerobic granular sludge, could be employed for the treatment of municipal and industrial wastewaters in near future. This chapter attempts to provide an up-to-date review on the definition, cultivation, characterization, modeling and application of aerobic granular sludge for biological wastewater treatment. This review outlines some important discoveries with regard to the factors affecting the formation of aerobic granular sludge, their physicochemical characteristics, as well as their microbial structure and diversity. It also summarizes the modeling of aerobic granule formation. Finally, this chapter highlights the applications of aerobic granulation technology in the biological wastewater treatment. It is concluded that the knowledge regarding aerobic granular sludge is far from complete. Although previous studies in this field have undoubtedly improved our understanding on aerobic granular sludge, it is clear that much remains to be learned about the process and that many unanswered questions still remain. One of the challenges appears to be the integration of the existing and growing scientific knowledge base with the observations and applications in practice, which this paper hopes to partially achieve.

L-Arginine Affects Aerobic Capacity and Muscle Metabolism in MELAS (Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-Like Episodes) Syndrome.

PubMed

Rodan, Lance H; Wells, Greg D; Banks, Laura; Thompson, Sara; Schneiderman, Jane E; Tein, Ingrid

2015-01-01

To study the effects of L-arginine (L-Arg) on total body aerobic capacity and muscle metabolism as assessed by (31)Phosphorus Magnetic Resonance Spectroscopy ((31)P-MRS) in patients with MELAS (Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-like episodes) syndrome. We performed a case control study in 3 MELAS siblings (m.3243A>G tRNA(leu(UUR)) in MTTL1 gene) with different % blood mutant mtDNA to evaluate total body maximal aerobic capacity (VO(2peak)) using graded cycle ergometry and muscle metabolism using 31P-MRS. We then ran a clinical trial pilot study in MELAS sibs to assess response of these parameters to single dose and a 6-week steady-state trial of oral L-Arginine. At baseline (no L-Arg), MELAS had lower serum Arg (p = 0.001). On 3(1)P-MRS muscle at rest, MELAS subjects had increased phosphocreatine (PCr) (p = 0.05), decreased ATP (p = 0.018), and decreased intracellular Mg(2+) (p = 0.0002) when compared to matched controls. With L-arginine therapy, the following trends were noted in MELAS siblings on cycle ergometry: (1) increase in mean % maximum work at anaerobic threshold (AT) (2) increase in % maximum heart rate at AT (3) small increase in VO(2peak). On (31)P-MRS the following mean trends were noted: (1) A blunted decrease in pH after exercise (less acidosis) (2) increase in Pi/PCr ratio (ADP) suggesting increased work capacity (3) a faster half time of PCr recovery (marker of mitochondrial activity) following 5 minutes of moderate intensity exercise (4) increase in torque. These results suggest an improvement in aerobic capacity and muscle metabolism in MELAS subjects in response to supplementation with L-Arg. Intramyocellular hypomagnesemia is a novel finding that warrants further study. Class III evidence that L-arginine improves aerobic capacity and muscle metabolism in MELAS subjects. ClinicalTrials.gov NCT01603446.

Acute aerobic exercise: an intervention for the selective visual attention and reading comprehension of low-income adolescents

PubMed Central

Tine, Michele

2014-01-01

There is a need for feasible and research-based interventions that target the cognitive performance and academic achievement of low-income adolescents. In response, this study utilized a randomized experimental design and assessed the selective visual attention (SVA) and reading comprehension abilities of low-income adolescents and, for comparison purposes, high-income adolescents after they engaged in 12-min of aerobic exercise. The results suggest that 12-min of aerobic exercise improved the SVA of low- and high-income adolescents and that the benefit lasted for 45-min for both groups. The SVA improvement among the low-income adolescents was particularly large. In fact, the SVA improvement among the low-income adolescents was substantial enough to eliminate a pre-existing income gap in SVA. The mean reading comprehension score of low-income adolescents who engaged in 12-min of aerobic exercise was higher than the mean reading comprehension score of low-income adolescents in the control group. However, there was no difference between the mean reading comprehension scores of the high-income adolescents who did and did not engage in 12-min of aerobic exercise. Based on the results, schools serving low-income adolescents should consider implementing brief sessions of aerobic exercise during the school day. PMID:24966846

Acute aerobic exercise: an intervention for the selective visual attention and reading comprehension of low-income adolescents.

PubMed

Tine, Michele

2014-01-01

There is a need for feasible and research-based interventions that target the cognitive performance and academic achievement of low-income adolescents. In response, this study utilized a randomized experimental design and assessed the selective visual attention (SVA) and reading comprehension abilities of low-income adolescents and, for comparison purposes, high-income adolescents after they engaged in 12-min of aerobic exercise. The results suggest that 12-min of aerobic exercise improved the SVA of low- and high-income adolescents and that the benefit lasted for 45-min for both groups. The SVA improvement among the low-income adolescents was particularly large. In fact, the SVA improvement among the low-income adolescents was substantial enough to eliminate a pre-existing income gap in SVA. The mean reading comprehension score of low-income adolescents who engaged in 12-min of aerobic exercise was higher than the mean reading comprehension score of low-income adolescents in the control group. However, there was no difference between the mean reading comprehension scores of the high-income adolescents who did and did not engage in 12-min of aerobic exercise. Based on the results, schools serving low-income adolescents should consider implementing brief sessions of aerobic exercise during the school day.

Metaproteomics reveals major microbial players and their biodegradation functions in a large-scale aerobic composting plant

PubMed Central

Liu, Dongming; Li, Mingxiao; Xi, Beidou; Zhao, Yue; Wei, Zimin; Song, Caihong; Zhu, Chaowei

2015-01-01

Composting is an appropriate management alternative for municipal solid waste; however, our knowledge about the microbial regulation of this process is still scare. We employed metaproteomics to elucidate the main biodegradation pathways in municipal solid waste composting system across the main phases in a large-scale composting plant. The investigation of microbial succession revealed that Bacillales, Actinobacteria and Saccharomyces increased significantly with respect to abundance in composting process. The key microbiologic population for cellulose degradation in different composting stages was different. Fungi were found to be the main producers of cellulase in earlier phase. However, the cellulolytic fungal communities were gradually replaced by a purely bacterial one in active phase, which did not support the concept that the thermophilic fungi are active through the thermophilic phase. The effective decomposition of cellulose required the synergy between bacteria and fungi in the curing phase. PMID:25989417

Aerobic Digestion. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

ERIC Educational Resources Information Center

Klopping, Paul H.

This lesson is a basic description of aerobic digestion. Topics presented include a general process overview discussion of a typical digester's components, factors influencing performance, operational controls, and biological considerations for successful operation. The lesson includes an instructor's guide and student workbook. The instructor's…

Validation of the FAST skating protocol to predict aerobic power in ice hockey players.

PubMed

Petrella, Nicholas J; Montelpare, William J; Nystrom, Murray; Plyley, Michael; Faught, Brent E

2007-08-01

Few studies have reported a sport-specific protocol to measure the aerobic power of ice hockey players using a predictive process. The purpose of our study was to validate an ice hockey aerobic field test on players of varying ages, abilities, and levels. The Faught Aerobic Skating Test (FAST) uses an on-ice continuous skating protocol on a course measuring 160 feet (48.8 m) using a CD to pace the skater with a beep signal to cross the starting line at each end of the course. The FAST incorporates the principle of increasing workload at measured time intervals during a continuous skating exercise. Step-wise multiple regression modelling was used to determine the estimate of aerobic power. Participants completed a maximal aerobic power test using a modified Bruce incremental treadmill protocol, as well as the on-ice FAST. Normative data were collected on 406 ice hockey players (291 males, 115 females) ranging in age from 9 to 25 y. A regression to predict maximum aerobic power was developed using body mass (kg), height (m), age (y), and maximum completed lengths of the FAST as the significant predictors of skating aerobic power (adjusted R2 = 0.387, SEE = 7.25 mL.kg-1.min-1, p < 0.0001). These results support the application of the FAST in estimating aerobic power among male and female competitive ice hockey players between the ages of 9 and 25 years.

Bacterial Contamination of Boar Semen and its Relationship to Sperm Quality Preserved in Commercial Extender Containing Gentamicin Sulfate.

PubMed

Gączarzewicz, D; Udała, J; Piasecka, M; Błaszczyk, B; Stankiewicz, T

2016-09-01

This study was designed to determine the degree and type of bacterial contamination in boar semen (79 ejaculates from Large White and Landrace boars) and its consequences for sperm quality during storage (27 extended semen samples, 16°C for five days) under practical conditions of artificial insemination (AI). The results revealed the presence of aerobic bacteria in 99% of the ejaculates (from 80 to 370 ×106 colony-forming units/mL). Most of the ejaculates contained two or three bacterial contaminants, while the Staphylococcus, Streptococcus, and Pseudomonas bacterial genera were most frequently isolated. Also detected were Enterobacter spp., Bacillus spp., Proteus spp., Escherichia coli, P. fluorescens, and P. aeruginosa. In general, the growth of certain bacterial types isolated prior to semen processing (Enterobacter spp., E. coli, P. fluorescens, and P. aeruginosa) was not discovered on different days of storage, but fluctuations (with a tendency towards increases) were found in the frequencies of Bacillus spp., Pseudomonas spp., and Staphylococcus spp. isolates up to the end of storage. Semen preserved for five days exhibited decreases in sperm motility and increases in the average number of total aerobic bacteria; this was associated with sperm agglutination, plasma membrane disruption, and acrosome damage. We inferred that, due to the different degrees and types of bacterial contaminants in the boar ejaculates, the inhibitory activity of some antimicrobial agents used in swine extenders (such as gentamicin sulfate) may be limited. Because such agents can contribute to the overgrowth of certain aerobic bacteria and a reduction in the quality of stored semen, procedures with high standards of hygiene and microbiological control should be used when processing boar semen.

Aerobic mineralization of MTBE and tert-butyl alcohol by stream-bed sediment microorganisms

USGS Publications Warehouse

Bradley, P.M.; Landmeyer, J.E.; Chapelle, F.H.

1999-01-01

Microorganisms indigenous to the stream-bed sediments at two gasoline- contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-14C]-MTBE and 84% of [U-14C]-TBA were degraded to 14CO2 under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.Microorganisms indigenous to the stream-bed sediments at two gasoline-contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-14C]-MTBE and 84% of [U-14C]-TBA were degraded to 14CO2 under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.

Identifying Cis-Regulatory Changes Involved in the Evolution of Aerobic Fermentation in Yeasts

PubMed Central

Lin, Zhenguo; Wang, Tzi-Yuan; Tsai, Bing-Shi; Wu, Fang-Ting; Yu, Fu-Jung; Tseng, Yu-Jung; Sung, Huang-Mo; Li, Wen-Hsiung

2013-01-01

Gene regulation change has long been recognized as an important mechanism for phenotypic evolution. We used the evolution of yeast aerobic fermentation as a model to explore how gene regulation has evolved and how this process has contributed to phenotypic evolution and adaptation. Most eukaryotes fully oxidize glucose to CO2 and H2O in mitochondria to maximize energy yield, whereas some yeasts, such as Saccharomyces cerevisiae and its relatives, predominantly ferment glucose into ethanol even in the presence of oxygen, a phenomenon known as aerobic fermentation. We examined the genome-wide gene expression levels among 12 different yeasts and found that a group of genes involved in the mitochondrial respiration process showed the largest reduction in gene expression level during the evolution of aerobic fermentation. Our analysis revealed that the downregulation of these genes was significantly associated with massive loss of binding motifs of Cbf1p in the fermentative yeasts. Our experimental assays confirmed the binding of Cbf1p to the predicted motif and the activator role of Cbf1p. In summary, our study laid a foundation to unravel the long-time mystery about the genetic basis of evolution of aerobic fermentation, providing new insights into understanding the role of cis-regulatory changes in phenotypic evolution. PMID:23650209

Transformation and Sorption of Illicit Drug Biomarkers in Sewer Systems: Understanding the Role of Suspended Solids in Raw Wastewater.

PubMed

Ramin, Pedram; Libonati Brock, Andreas; Polesel, Fabio; Causanilles, Ana; Emke, Erik; de Voogt, Pim; Plósz, Benedek Gy

2016-12-20

Sewer pipelines, although primarily designed for sewage transport, can also be considered as bioreactors. In-sewer processes may lead to significant variations of chemical loadings from source release points to the treatment plant influent. In this study, we assessed in-sewer utilization of growth substrates (primary metabolic processes) and transformation of illicit drug biomarkers (secondary metabolic processes) by suspended biomass. Sixteen drug biomarkers were targeted, including mephedrone, methadone, cocaine, heroin, codeine, and tetrahydrocannabinol (THC) and their major human metabolites. Batch experiments were performed under aerobic and anaerobic conditions using raw wastewater. Abiotic biomarker transformation and partitioning to suspended solids and reactor wall were separately investigated under both redox conditions. A process model was identified by combining and extending the Wastewater Aerobic/anaerobic Transformations in Sewers (WATS) model and Activated Sludge Model for Xenobiotics (ASM-X). Kinetic and stoichiometric model parameters were estimated using experimental data via the Bayesian optimization method DREAM (ZS) . Results suggest that biomarker transformation significantly differs from aerobic to anaerobic conditions, and abiotic conversion is the dominant mechanism for many of the selected substances. Notably, an explicit description of biomass growth during batch experiments was crucial to avoid significant overestimation (up to 385%) of aerobic biotransformation rate constants. Predictions of in-sewer transformation provided here can reduce the uncertainty in the estimation of drug consumption as part of wastewater-based epidemiological studies.

Aerobic oxidations catalyzed by chromium corroles.

PubMed

Mahammed, Atif; Gray, Harry B; Meier-Callahan, Alexandre E; Gross, Zeev

2003-02-05

Oxochromium(V) complexes of 5,10,15-tris(pentafluorophenyl)corrole and brominated derivatives oxygenate substrates (triphenylphosphine and norbornene) with concomitant production of chromium(III). Regeneration of CrVO by reaction of dioxygen with CrIII completes an aerobic catalytic cycle, with very large solvent effects; in acetonitrile, rapid initial turnovers observed initially are shut down by formation of CrIVO, while in toluene, THF, and methanol, relatively slow reactions are further inhibited by product formation.

Characterization of rice (Oryza sativa L.) genotypes on the basis of morpho-physiological and biochemical traits grown under aerobic situation in rainfed ecosystem .

PubMed

Kumar, Santosh; Dwivedi, Sharad Kumar; Singh, S S; Kumar, Sanjeev; Sundaram, R K; Shivani; Mall, A K

2015-07-01

The objective of the present study was to examine the effect of aerobic situation on yield, physiological and biochemical traits of advanced breeding lines of rice. Experiment was conducted with two set of rice genotypes under two water regimes (aerobic and irrigated), during three consecutive wet seasons 2010-2012. Significant decrease in yield was observed in rice genotypes grown under aerobic situation as compared to the irrigated ones. Promising rice genotypes having the ability to maintain high plant biomass, harvest index, early vegetative vigour, improved physiological and biochemical traits in terms of relative water content (RWC), leaf area index (LAI), total soluble sugar, starch, protien and proline content help to sustain higher grain yield under aerobic situation. The yield gap between aerobic and irrigated rice ranged between 24% to 68%. Grain yield showed positive correlation with harvest index (0.434), test weight (0.647), plant biomass (0.411) and effective tiller numbers (0.473), whereas spikelet sterility was negative associated (-0.380). The current study suggested that promising genotypes viz., IR77298-14-1-2-130-2, IR84899-B-182-3-1-1-2, IR84887-B-157-38-1-1-3 and IR 84899-B-179-1-1-1-2 for aerobic situation, showing yield advantage due to better performance of physiological and biochemical traits, might be adopted in large area of rainfed ecosystem as well as in irrigated areas where water scarcity was a major problem.

Acute aerobic exercise helps overcome emotion regulation deficits.

PubMed

Bernstein, Emily E; McNally, Richard J

2017-06-01

Although colloquial wisdom and some studies suggest an association between regular aerobic exercise and emotional well-being, the nature of this link remains poorly understood. We hypothesised that aerobic exercise may change the way people respond to their emotions. Specifically, we tested whether individuals experiencing difficulties with emotion regulation would benefit from a previous session of exercise and show swifter recovery than their counterparts who did not exercise. Participants (N = 80) completed measures of emotion response tendencies, mood, and anxiety, and were randomly assigned to either stretch or jog for 30 minutes. All participants then underwent the same negative and positive mood inductions, and reported their emotional responses. Analyses showed that more perceived difficulty generating regulatory strategies and engaging in goal-directed behaviours after the negative mood induction predicted more intense and persistent negative affect in response to the stressor, as would be expected. Interactions revealed that aerobic exercise attenuated these effects. Moderate aerobic exercise may help attenuate negative emotions for participants initially experiencing regulatory difficulties. This study contributes to the literature on aerobic exercise's therapeutic effects with experimental data, specifically in the realm of emotional processing.

An integrated aerobic-anaerobic strategy for performance enhancement of Pseudomonas aeruginosa-inoculated microbial fuel cell.

PubMed

Yong, Xiao-Yu; Yan, Zhi-Ying; Shen, Hai-Bo; Zhou, Jun; Wu, Xia-Yuan; Zhang, Li-Juan; Zheng, Tao; Jiang, Min; Wei, Ping; Jia, Hong-Hua; Yong, Yang-Chun

2017-10-01

Microbial fuel cell (MFC) is a promising device for energy generation and organic waste treatment simultaneously by electrochemically active bacteria (EAB). In this study, an integrated aerobic-anaerobic strategy was developed to improve the performance of P. aeruginosa-inoculated MFC. With an aerobic start-up and following an anaerobic discharge process, the current density of MFC reached a maximum of 99.80µA/cm 2 , which was 91.6% higher than the MFC with conventional constant-anaerobic operation. Cyclic voltammetry and HPLC analysis showed that aerobic start-up significantly increased electron shuttle (pyocyanin) production (76% higher than the constant-anaerobic MFC). Additionally, enhanced anode biofilm formation was also observed in the integrated aerobic-anaerobic MFC. The increased pyocyanin production and biofilm formation promoted extracellular electron transfer from EAB to the anode and were the underlying mechanism for the MFC performance enhancement. This work demonstrated the integrated aerobic-anaerobic strategy would be a practical strategy to enhance the electricity generation of MFC. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Bioinspired Catalytic Aerobic Oxidative C–H Functionalization of Primary Aliphatic Amines: Synthesis of 1,2-Disubstituted Benzimidazoles

PubMed Central

Nguyen, Khac Minh Huy; Largeron, Martine

2015-01-01

Aerobic oxidative C–H functionalization of primary aliphatic amines has been accomplished with a biomimetic cooperative catalytic system to furnish 1,2-disubstituted benzimidazoles that play an important role as drug discovery targets. This one-pot atom-economical multistep process, which proceeds under mild conditions, with ambient air and equimolar amounts of each coupling partner, constitutes a convenient environmentally friendly strategy to functionalize non-activated aliphatic amines that remain challenging substrates for non-enzymatic catalytic aerobic systems. PMID:26206475

Screening identification of aerobic denitrification bacteria with high soil desalinization capacity

NASA Astrophysics Data System (ADS)

Jin, H.; Chen, H.; Jin, H.; Qian, Y.; Zhang, K.

2017-08-01

In order to study the mechanism of bacteria used in the saline soil remediation process, the aerobic denitrification bacteria were isolated from an agricultural greenhouse soil in a farm in East China’s Zhejiang Province. The identification, nitrogen reducing characteristics and the denitrification effect of bacteria from different soils at various locations were investigated. The results showed that the NO3- removal rate was 91% with bacteria from the greenhouse soil under aerobic conditions in 52 h, and the bacteria were identified as Gram-positive Castellaniella denitrification bacteria.

Promoting Neuroplasticity for Motor Rehabilitation After Stroke: Considering the Effects of Aerobic Exercise and Genetic Variation on Brain-Derived Neurotrophic Factor

PubMed Central

Mang, Cameron S.; Campbell, Kristin L.; Ross, Colin J.D.

2013-01-01

Recovery of motor function after stroke involves relearning motor skills and is mediated by neuroplasticity. Recent research has focused on developing rehabilitation strategies that facilitate such neuroplasticity to maximize functional outcome poststroke. Although many molecular signaling pathways are involved, brain-derived neurotrophic factor (BDNF) has emerged as a key facilitator of neuroplasticity involved in motor learning and rehabilitation after stroke. Thus, rehabilitation strategies that optimize BDNF effects on neuroplasticity may be especially effective for improving motor function poststroke. Two potential poststroke rehabilitation strategies that consider the importance of BDNF are the use of aerobic exercise to enhance brain function and the incorporation of genetic information to individualize therapy. Converging evidence demonstrates that aerobic exercise increases BDNF production and consequently enhances learning and memory processes. Nevertheless, a common genetic variant reduces activity-dependent secretion of the BDNF protein. Thus, BDNF gene variation may affect response to motor rehabilitation training and potentially modulate the effects of aerobic exercise on neuroplasticity. This perspective article discusses evidence that aerobic exercise promotes neuroplasticity by increasing BDNF production and considers how aerobic exercise may facilitate the acquisition and retention of motor skills for poststroke rehabilitation. Next, the impact of the BDNF gene val66met polymorphism on motor learning and response to rehabilitation is explored. It is concluded that the effects of aerobic exercise on BDNF and motor learning may be better exploited if aerobic exercise is paired more closely in time with motor training. Additionally, information about BDNF genotype could provide insight into the type and magnitude of effects that aerobic exercise may have across individuals and potentially help guide an individualized prescription of aerobic exercise to enhance motor rehabilitation poststroke. PMID:23907078

Has aerobic exercise effect on pain perception in persons with migraine and coexisting tension-type headache and neck pain? A randomized, controlled, clinical trial.

PubMed

Krøll, L S; Sjödahl Hammarlund, C; Gard, G; Jensen, R H; Bendtsen, L

2018-04-10

A large subset of persons with migraine suffers from coexisting tension-type headache and neck pain which may adversely affect the prognosis of migraine. Aerobic exercise has been shown to decrease migraine burden in these persons. Therefore, the aim of this study was to investigate whether the effect of aerobic exercise in persons with migraine and coexisting tension-type headache and neck pain can be explained by changes in pain perception. Seventy consecutively recruited persons with migraine and coexisting tension-type headache and neck pain were randomized into exercise group or control group. Aerobic exercise consisted of bike/cross-trainer/brisk walking for 45 min, three times/week for 3 months. Controls continued their usual daily activities. Pericranial tenderness, pain thresholds, supra-thresholds and temporal summation were assessed at baseline, after treatment and at follow-up (6 months from baseline). Fifty-two persons with migraine and coexisting tension-type headache and neck pain completed the study. Aerobic exercise did not induce consistent changes in nociceptive pathways measured by pericranial tenderness, pressure pain thresholds and sensitivity to electrical stimulation. The effect of aerobic exercise cannot be explained by measurable effects on the pain modulation system. Thus, the positive effect on migraine burden may rather be explained by positive alteration of avoidance behaviour. Aerobic exercise can be recommended as a safe and inexpensive migraine treatment strategy. This study adds further knowledge about the positive effect of aerobic exercise for persons with migraine and coexisting tension-type headache and neck pain. This effect cannot be measured by changes in pain modulation, but may rather be explained by positive alteration of avoidance behaviour. © 2018 European Pain Federation - EFIC®.

Electron transfer to nitrogenase in different genomic and metabolic backgrounds.

PubMed

Poudel, Saroj; Colman, Daniel R; Fixen, Kathryn R; Ledbetter, Rhesa N; Zheng, Yanning; Pence, Natasha; Seefeldt, Lance C; Peters, John W; Harwood, Caroline S; Boyd, Eric S

2018-02-26

Nitrogenase catalyzes the reduction of dinitrogen (N 2 ) using low potential electrons from ferredoxin (Fd) or flavodoxin (Fld) through an ATP dependent process. Since its emergence in an anaerobic chemoautotroph, this oxygen (O 2 ) sensitive enzyme complex has evolved to operate in a variety of genomic and metabolic backgrounds including those of aerobes, anaerobes, chemotrophs, and phototrophs. However, whether pathways of electron delivery to nitrogenase are influenced by these different metabolic backgrounds is not well understood. Here, we report the distribution of homologs of Fds, Flds, and Fd/Fld-reducing enzymes in 359 genomes of putative N 2 fixers (diazotrophs). Six distinct lineages of nitrogenase were identified and their distributions largely corresponded to differences in the host cells' ability to integrate O 2 or light into energy metabolism. Predicted pathways of electron transfer to nitrogenase in aerobes, facultative anaerobes, and phototrophs varied from those in anaerobes at the level of Fds/Flds used to reduce nitrogenase, the enzymes that generate reduced Fds/Flds, and the putative substrates of these enzymes. Proteins that putatively reduce Fd with hydrogen or pyruvate were enriched in anaerobes, while those that reduce Fd with NADH/NADPH were enriched in aerobes, facultative anaerobes, and anoxygenic phototrophs. The energy metabolism of aerobic, facultatively anaerobic, and anoxygenic phototrophic diazotrophs often yields reduced NADH/NADPH that is not sufficiently reduced to drive N 2 reduction. At least two mechanisms have been acquired by these taxa to overcome this limitation and to generate electrons with potentials capable of reducing Fd. These include the bifurcation of electrons or the coupling of Fd reduction to reverse ion translocation. IMPORTANCE Nitrogen fixation supplies fixed nitrogen to cells from a variety of genomic and metabolic backgrounds including those of aerobes, facultative anaerobes, chemotrophs, and phototrophs. Here, using informatics approaches applied to genomic data, we show that pathways of electron transfer to nitrogenase in metabolically diverse diazotrophic taxa have diversified primarily in response to host cells' acquired ability to integrate O 2 or light into their energy metabolism. Acquisition of two key enzyme complexes enabled aerobic and facultatively anaerobic phototrophic taxa to generate electrons of sufficiently low potential to reduce nitrogenase: the bifurcation of electrons via the Fix complex or the coupling of Fd reduction to reverse ion translocation via the Rhodobacter nitrogen fixation (Rnf) complex. Copyright © 2018 American Society for Microbiology.

Towards sustainable pollution management

NASA Astrophysics Data System (ADS)

Jern, N. G. W.

2017-03-01

It is often overlooked pollution control itself may not be entirely free from adverse impact on the environment if considered from a more holistic perspective. For example mechanised wastewater treatment is energy intensive and so has a carbon footprint because of the need to move air to supply oxygen to the aerobic treatment process. The aerobic treatment process then results in excess bio-sludge which requires disposal and if such is not appropriately performed, then there is risk of surface and groundwater contamination. This presentation explores the changes which have been investigated and are beginning to be implemented in wastewater, sludge, and agro-industrial wastes management which are more environmentally benign. Three examples shall be used to illustrate the discussion. The first example uses the conventional sewage treatment system with a unit process arrangement which converts carbonaceous pollutants from soluble and colloidal forms to particulate forms with an aerobic process before attempting energy recovery with an anaerobic process. Such an arrangement does, however, result in a negative energy balance. This is not withstanding the fact there is potentially more energy in sewage than is required to treat it if that energy can be effectively harvested. The latter can be achieved by removing the carbonaceous pollutants before the aerobic process and thereby using the aerobic process for polishing instead of treating. The carbonaceous pollutants so recovered then becomes the feed for the anaerobic process. Unfortunately conventional anaerobic sludge digestion only removes 35-45% of the organic material fed. Since biogas production (and hence energy recovery) is linked to the amount of organic material which can be degraded anaerobically, the effectiveness of the anaerobic digestion process needs to be improved. Contrary to a commonly held belief wherein methanogenesis is the “bottleneck” in anaerobic processes, hydrolysis is in sludge digestion. Hydrolysis can be enhanced thermally, chemically and biologically. With better anaerobic digestion, the digestate would have more N and P released. The digestate can be blended with organic fertilizers which have been augmented with microbes capable of producing phytohormones. The latter enable crop plants to use inorganic fertilizers more effectively and hence reducing the quantity of inorganic fertilizers required significantly. Use of such organic fertilizers rejuvenates soils which have been subjected to prolonged application of inorganic fertilisers since the latter can result in stagnating or even declining crop yields.

Effects of Physical Activity on Children's Executive Function: Contributions of Experimental Research on Aerobic Exercise

ERIC Educational Resources Information Center

Best, John R.

2010-01-01

Executive function refers to the cognitive processes necessary for goal-directed cognition and behavior, which develop across childhood and adolescence. Recent experimental research indicates that both acute and chronic aerobic exercise promote children's executive function. Furthermore, there is tentative evidence that not all forms of aerobic…

Optimum temperature in juvenile salmonids: connecting subcellular indicators to tissue function and whole-organism thermal optimum.

PubMed

Anttila, Katja; Casselman, Matthew T; Schulte, Patricia M; Farrell, Anthony P

2013-01-01

Temperature affects processes at all levels of biological organization, but it is unclear whether processes at different levels have similar thermal optima (T(opt)). Here, we compare the T(opt) for aerobic scope, a whole-organism measure of performance, with both the Arrhenius breakpoint temperature for maximum heart rate (HR-ABT), a measure of tissue level performance, and the temperature at which AMP-activated protein kinase (AMPK) is phosphorylated in the heart, an indicator of an increase in dependence on anaerobic energy metabolism at the cellular level in juvenile rainbow trout Oncorhynchus mykiss. The T(opt) for aerobic scope was 19°C, with aerobic scope being maintained at ≥90% of maximum (termed a "T(opt) window") from 16.5° to 20.5°C. HR-ABT occurred at [Formula: see text], while the profile of AMPK phosphorylation started to change from baseline at 19°C, suggesting that these processes have similar thermal sensitivities as a fish is warmed to T(opt). The effects of temperature on AMPK phosphorylation were also measured in coho salmon Oncorhynchus kisutch hearts and compared with previously published values for HR-ABT and aerobic scope T(opt). AMPK phosphorylation in coho hearts began to change at temperatures above 17°C, which again is comparable with the published T(opt) for aerobic scope (17°C) and HR-ABT ([Formula: see text]) in these individuals. Thus, the thermal sensitivity of these subcellular, tissue, and whole-organism functions are highly correlated in both rainbow trout and coho salmon and may depend on each other.

Recovery of Nickel and Cobalt from Laterite Tailings by Reductive Dissolution under Aerobic Conditions Using Acidithiobacillus Species.

PubMed

Marrero, J; Coto, O; Goldmann, S; Graupner, T; Schippers, A

2015-06-02

Biomining of sulfidic ores has been applied for almost five decades. However, the bioprocessing of oxide ores such as laterites lags commercially behind. Recently, the Ferredox process was proposed to treat limonitic laterite ores by means of anaerobic reductive dissolution (AnRD), which was found to be more effective than aerobic bioleaching by fungi and other bacteria. We show here that the ferric iron reduction mediated by Acidithiobacillus thiooxidans can be applied to an aerobic reductive dissolution (AeRD) of nickel laterite tailings. AeRD using a consortium of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans extracted similar amounts of nickel (53-57%) and cobalt (55-60%) in only 7 days as AnRD using Acidithiobacillus ferrooxidans. The economic and environmental advantages of AeRD for processing of laterite tailings comprise no requirement for an anoxic atmosphere, 1.8-fold less acid consumption than for AnRD, as well as nickel and cobalt recovered in a ferrous-based pregnant leach solution (PLS), facilitating the subsequent metal recovery. In addition, an aerobic acid regeneration stage is proposed. Therefore, AeRD process development can be considered as environmentally friendly for treating laterites with low operational costs and as an attractive alternative to AnRD.

Natural attenuation of chlorinated solvents at Area 6, Dover Air Force Base: Groundwater biogeochemistry

USGS Publications Warehouse

Witt, M.E.; Klecka, G.M.; Lutz, E.J.; Ei, T.A.; Grosso, N.R.; Chapelle, F.H.

2002-01-01

Monitored natural attenuation (MNA) has recently emerged as a viable groundwater remediation technology in the United States. Area 6 at Dover Air Force Base (Dover, DE) was chosen as a test site to examine the potential for MNA of tetrachloroethene (PCE) and trichloroethene (TCE) in groundwater and aquifer sediments. A "lines of evidence" approach was used to document the occurrence of natural attenuation. Chlorinated hydrocarbon and biogeochemical data were used to develop a site-specific conceptual model where both anaerobic and aerobic biological processes are responsible for the destruction of PCE, TCE, and daughter metabolites. An examination of groundwater biogeochemical data showed a region of depleted dissolved oxygen with elevated dissolved methane and hydrogen concentrations. Reductive dechlorination likely dominated in the anaerobic portion of the aquifer where PCE and TCE levels were observed to decrease with a simultaneous increase in cis-1,2-dichloroethene (cis-DCE), vinyl chloride (VC), ethene, and dissolved chloride. Near the anaerobic/aerobic interface, concentrations of cis-DCE and VC decreased to below detection limits, presumably due to aerobic biotransformation processes. Therefore, the contaminant and daughter product plumes present at the site appear to have been naturally attenuated by a combination of active anaerobic and aerobic biotransformation processes. ?? 2002 Elsevier Science B.V. All rights reserved.

Inhibitory effect of self-generated extracellular dissolved organic carbon on carbon dioxide fixation in sulfur-oxidizing bacteria during a chemoautotrophic cultivation process and its elimination.

PubMed

Wang, Ya-Nan; Tsang, Yiu Fai; Wang, Lei; Fu, Xiaohua; Hu, Jiajun; Li, Huan; Le, Yiquan

2018-03-01

The features of extracellular dissolved organic carbon (EDOC) generation in two typical aerobic sulfur-oxidizing bacteria (Thiobacillus thioparus DSM 505 and Halothiobacillus neapolitanus DSM 15147) and its impact on CO 2 fixation during chemoautotrophic cultivation process were investigated. The results showed that EDOC accumulated in both strains during CO 2 fixation process. Large molecular weight (MW) EDOC derived from cell lysis and decay was dominant during the entire process in DSM 505, whereas small MW EDOC accounted for a large proportion during initial and middle stages of DSM 15147 as its cytoskeleton synthesis rate did not keep up with CO 2 assimilation rate. The self-generated EDOC feedback repressed cbb gene transcription and thus decreased total bacterial cell number and CO 2 fixation yield in both strains, but DSM 505 was more sensitive to this inhibition effect. Moreover, the membrane bioreactor effectively decreased the EDOC/TOC ratio and improved carbon fixation yield of DSM 505. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characteristics and performance of aerobic algae-bacteria granular consortia in a photo-sequencing batch reactor.

PubMed

Liu, Lin; Zeng, Zhichao; Bee, Mingyang; Gibson, Valerie; Wei, Lili; Huang, Xu; Liu, Chaoxiang

2018-05-05

The characteristics and performance of algae-bacteria granular consortia which cultivated with aerobic granules and targeted algae (Chlorella and Scenedesmus), and the essential difference between granular consortia and aerobic granules were investigated in this experiment. The result indicated that algae-bacteria granular consortia could be successfully developed, and the algae present in the granular consortia were mainly Chlorella and Scenedesmus. Although the change of chlorophyll composition revealed the occurrence of light limitation for algal growth, the granular consortia could maintain stable granular structure, and even showed better settling property than aerobic granules. Total nitrogen and phosphate in the algal-bacterial granular system showed better removal efficiencies (50.2% and 35.7%) than those in the aerobic granular system (32.8% and 25.6%) within one cycle (6 h). The biodiesel yield of aerobic granules could be significantly improved by algal coupled process, yet methyl linolenate and methyl palmitoleate were the dominant composition of biodiesel obtained from granular consortia and aerobic granules, respectively. Meanwhile, the difference of dominant bacterial communities in the both granules was found at the order level and family level, and alpha diversity indexes revealed the granular consortia had a higher microbial diversity. Copyright © 2018. Published by Elsevier B.V.

Aerobic exercise increases hippocampal volume and improves memory in multiple sclerosis: preliminary findings.

PubMed

Leavitt, V M; Cirnigliaro, C; Cohen, A; Farag, A; Brooks, M; Wecht, J M; Wylie, G R; Chiaravalloti, N D; DeLuca, J; Sumowski, J F

2014-01-01

Multiple sclerosis leads to prominent hippocampal atrophy, which is linked to memory deficits. Indeed, 50% of multiple sclerosis patients suffer memory impairment, with negative consequences for quality of life. There are currently no effective memory treatments for multiple sclerosis either pharmacological or behavioral. Aerobic exercise improves memory and promotes hippocampal neurogenesis in nonhuman animals. Here, we investigate the benefits of aerobic exercise in memory-impaired multiple sclerosis patients. Pilot data were collected from two ambulatory, memory-impaired multiple sclerosis participants randomized to non-aerobic (stretching) and aerobic (stationary cycling) conditions. The following baseline/follow-up measurements were taken: high-resolution MRI (neuroanatomical volumes), fMRI (functional connectivity), and memory assessment. Intervention was 30-minute sessions 3 times per week for 3 months. Aerobic exercise resulted in 16.5% increase in hippocampal volume and 53.7% increase in memory, as well as increased hippocampal resting-state functional connectivity. Improvements were specific, with no comparable changes in overall cerebral gray matter (+2.4%), non-hippocampal deep gray matter structures (thalamus, caudate: -4.0%), or in non-memory cognitive functioning (executive functions, processing speed, working memory: changes ranged from -11% to +4%). Non-aerobic exercise resulted in relatively no change in hippocampal volume (2.8%) or memory (0.0%), and no changes in hippocampal functional connectivity. This is the first evidence for aerobic exercise to increase hippocampal volume and connectivity and improve memory in multiple sclerosis. Aerobic exercise represents a cost-effective, widely available, natural, and self-administered treatment with no adverse side effects that may be the first effective memory treatment for multiple sclerosis patients.

Effect of Applying Molasses and Propionic Acid on Fermentation Quality and Aerobic Stability of Total Mixed Ration Silage Prepared with Whole-plant Corn in Tibet

PubMed Central

Chen, Lei; Guo, Gang; Yuan, Xianjun; Shimojo, Masataka; Yu, Chengqun; Shao, Tao

2014-01-01

The objective of this study was to evaluate the effects of molasses and propionic acid on the fermentation quality and aerobic stability of total mixed ration (TMR) silages prepared with whole-plant corn in Tibet. TMR (354 g/kg DM) was ensiled with four different treatments: no additive (control), molasses (M), propionic acid (P), and molasses+propionic acid (PM), in laboratory silos (250 mL) and fermented for 45 d. Silos were opened and silages were subjected to an aerobic stability test for 12 days, in which chemical and microbiological parameters of TMR silages were measured to determined the aerobic deterioration. After 45 d of ensiling, the four TMR silages were of good quality with low pH value and ammonia/total N (AN), and high lactic acid (LA) content and V-scores. M silage showed the highest (p<0.05) LA content and higher dry matter (DM) recovery than the control and P silages. P silage had lower (p<0.05) LA content than the control silage. During aerobic exposure, lactic acid contents decreased gradually in the control and M silages, while that of P and PM silages increased, and the peak values were observed after 9 d. M silage had similar yeast counts with the control silage (>105 cfu/g FM), however, it appeared to be more stable as indicated by a delayed pH value increase. P and PM silages showed fewer yeasts (<105 cfu/g FM) (p<0.05) and were more stable than the control and M silages during aerobic exposure. It was concluded that M application increased LA content and improved aerobic stability of TMR silage prepared with whole-plant corn in Tibet. P application inhibited lactic acid production during ensiling, and apparently preserved available sugars which stimulated large increases in lactic acid during aerobic exposure stage, which resulted in greater aerobic stability of TMR silage. PMID:25049961

Aerobic Exercise Intervention, Cognitive Performance, and Brain Structure: Results from the Physical Influences on Brain in Aging (PHIBRA) Study.

PubMed

Jonasson, Lars S; Nyberg, Lars; Kramer, Arthur F; Lundquist, Anders; Riklund, Katrine; Boraxbekk, Carl-Johan

2016-01-01

Studies have shown that aerobic exercise has the potential to improve cognition and reduce brain atrophy in older adults. However, the literature is equivocal with regards to the specificity or generality of these effects. To this end, we report results on cognitive function and brain structure from a 6-month training intervention with 60 sedentary adults (64-78 years) randomized to either aerobic training or stretching and toning control training. Cognitive functions were assessed with a neuropsychological test battery in which cognitive constructs were measured using several different tests. Freesurfer was used to estimate cortical thickness in frontal regions and hippocampus volume. Results showed that aerobic exercisers, compared to controls, exhibited a broad, rather than specific, improvement in cognition as indexed by a higher "Cognitive score," a composite including episodic memory, processing speed, updating, and executive function tasks ( p = 0.01). There were no group differences in cortical thickness, but additional analyses revealed that aerobic fitness at baseline was specifically related to larger thickness in dorsolateral prefrontal cortex (dlPFC), and hippocampus volume was positively associated with increased aerobic fitness over time. Moreover, "Cognitive score" was related to dlPFC thickness at baseline, but changes in "Cognitive score" and dlPFC thickness were associated over time in the aerobic group only. However, aerobic fitness did not predict dlPFC change, despite the improvement in "Cognitive score" in aerobic exercisers. Our interpretation of these observations is that potential exercise-induced changes in thickness are slow, and may be undetectable within 6-months, in contrast to change in hippocampus volume which in fact was predicted by the change in aerobic fitness. To conclude, our results add to a growing literature suggesting that aerobic exercise has a broad influence on cognitive functioning, which may aid in explaining why studies focusing on a narrower range of functions have sometimes reported mixed results.

Aerobic Exercise Intervention, Cognitive Performance, and Brain Structure: Results from the Physical Influences on Brain in Aging (PHIBRA) Study

PubMed Central

Jonasson, Lars S.; Nyberg, Lars; Kramer, Arthur F.; Lundquist, Anders; Riklund, Katrine; Boraxbekk, Carl-Johan

2017-01-01

Studies have shown that aerobic exercise has the potential to improve cognition and reduce brain atrophy in older adults. However, the literature is equivocal with regards to the specificity or generality of these effects. To this end, we report results on cognitive function and brain structure from a 6-month training intervention with 60 sedentary adults (64–78 years) randomized to either aerobic training or stretching and toning control training. Cognitive functions were assessed with a neuropsychological test battery in which cognitive constructs were measured using several different tests. Freesurfer was used to estimate cortical thickness in frontal regions and hippocampus volume. Results showed that aerobic exercisers, compared to controls, exhibited a broad, rather than specific, improvement in cognition as indexed by a higher “Cognitive score,” a composite including episodic memory, processing speed, updating, and executive function tasks (p = 0.01). There were no group differences in cortical thickness, but additional analyses revealed that aerobic fitness at baseline was specifically related to larger thickness in dorsolateral prefrontal cortex (dlPFC), and hippocampus volume was positively associated with increased aerobic fitness over time. Moreover, “Cognitive score” was related to dlPFC thickness at baseline, but changes in “Cognitive score” and dlPFC thickness were associated over time in the aerobic group only. However, aerobic fitness did not predict dlPFC change, despite the improvement in “Cognitive score” in aerobic exercisers. Our interpretation of these observations is that potential exercise-induced changes in thickness are slow, and may be undetectable within 6-months, in contrast to change in hippocampus volume which in fact was predicted by the change in aerobic fitness. To conclude, our results add to a growing literature suggesting that aerobic exercise has a broad influence on cognitive functioning, which may aid in explaining why studies focusing on a narrower range of functions have sometimes reported mixed results. PMID:28149277

Effect of dissolved oxygen concentration (microaerobic and aerobic) on selective enrichment culture for bioaugmentation of acidic industrial wastewater.

PubMed

Quan, Ying; Han, Hui; Zheng, Shaokui

2012-09-01

The successful application of bioaugmentation is largely dependent on the selective enrichment of culture with regards to pH, temperature, salt, or specific toxic organic pollutants. In this study, we investigated the effect of dissolved oxygen (DO) concentrations (aerobic, >2 mg L(-1); microaerobic, <1 mg L(-1)) on yeast enrichment culture for bioaugmentation of acidic industrial wastewater (pH 3.9-4.7). Clone library analyses revealed that the yeast community shifted in response to different DO levels, and that Candida humilis and Candida pseudolambica were individually dominant in the aerobic and microaerobic enrichment cultures. This would significantly influence the isolation results, and further hinder bioaugmentation due to differences in DO environments during the enrichment and application periods. However, differences in the selective enrichment culture cannot be predicted based on differences in pollutant removal performance. Thus, DO concentrations (aerobic/microaerobic) should be considered a secondary selective pressure to achieve successful bioaugmentation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Loss of Abhd5 Promotes Colorectal Tumor Development and Progression by Inducing Aerobic Glycolysis and Epithelial-Mesenchymal Transition

PubMed Central

Ou, Juanjuan; Miao, Hongming; Ma, Yinyan; Guo, Feng; Deng, Jia; Wei, Xing; Zhou, Jie; Xie, Ganfeng; Shi, Hang; Xue, Bingzhong; Liang, Houjie; Yu, Liqing

2014-01-01

SUMMARY How cancer cells shift metabolism to aerobic glycolysis is largely unknown. Here we show that deficiency of α/β-hydrolase domain-containing-5 (Abhd5), an intracellular lipolytic activator that is also known as comparative gene identification-58 (CGI-58), promotes this metabolic shift and enhances malignancies of colorectal carcinomas (CRCs). Silencing of Abhd5 in normal fibroblasts induces malignant transformation. Intestine-specific knockout of Abhd5 in ApcMin/+ mice robustly increases tumorigenesis and malignant transformation of adenomatous polyps. In colon cancer cells, Abhd5 deficiency induces epithelial-mesenchymal transition by suppressing the AMPKα-p53 pathway, which is attributable to increased aerobic glycolysis. In human CRCs, Abhd5 expression falls substantially and correlates negatively with malignant features. Our study is the first to link Abhd5 to CRC pathogenesis. It suggests that cancer cells may develop aerobic glycolysis by suppressing Abhd5-mediated intracellular lipolysis. PMID:25482557

Aerobic glycolysis: meeting the metabolic requirements of cell proliferation.

PubMed

Lunt, Sophia Y; Vander Heiden, Matthew G

2011-01-01

Warburg's observation that cancer cells exhibit a high rate of glycolysis even in the presence of oxygen (aerobic glycolysis) sparked debate over the role of glycolysis in normal and cancer cells. Although it has been established that defects in mitochondrial respiration are not the cause of cancer or aerobic glycolysis, the advantages of enhanced glycolysis in cancer remain controversial. Many cells ranging from microbes to lymphocytes use aerobic glycolysis during rapid proliferation, which suggests it may play a fundamental role in supporting cell growth. Here, we review how glycolysis contributes to the metabolic processes of dividing cells. We provide a detailed accounting of the biosynthetic requirements to construct a new cell and illustrate the importance of glycolysis in providing carbons to generate biomass. We argue that the major function of aerobic glycolysis is to maintain high levels of glycolytic intermediates to support anabolic reactions in cells, thus providing an explanation for why increased glucose metabolism is selected for in proliferating cells throughout nature.

The one-stage autothermal thermophilic aerobic digestion for sewage sludge treatment: stabilization process and mechanism.

PubMed

Liu, Shugen; Zhu, Nanwen; Li, Loretta Y

2012-01-01

Batch experiment was carried out in a simulated thermophilic aerobic digester to investigate the digestion process of one-stage autothermal thermophilic aerobic digester and to explore the sludge stabilization mechanism. Volatile solids removal was 38.4% at 408 h and 45.0% at 552 h. Chemical oxidation demand, total nitrogen, and ammonia nitrogen in supernatant increased rapidly up to 168 h, and all of them fluctuated moderately after 360 h. Volatile fatty acid (VFA) accumulated rapidly up to 24 to 168 h, then declined sharply, reaching a low concentration after 312 h. Propionic, iso-valeric, and iso-butyric acids, in addition to acetic acids, were also the major components of VFA. As the biochemical metabolic process was inhibited under oxygen-deficiency condition, the digestion system can produce acetic, propionic, butyric acids and other VFA constituents to meet the demand for NAD(+) and maximize ATP generation. The ORP affected the VFA production and depletion as well as sulfate levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

Trace metal pyritization variability in response to mangrove soil aerobic and anaerobic oxidation processes.

PubMed

Machado, W; Borrelli, N L; Ferreira, T O; Marques, A G B; Osterrieth, M; Guizan, C

2014-02-15

The degree of iron pyritization (DOP) and degree of trace metal pyritization (DTMP) were evaluated in mangrove soil profiles from an estuarine area located in Rio de Janeiro (SE Brazil). The soil pH was negatively correlated with redox potential (Eh) and positively correlated with DOP and DTMP of some elements (Mn, Cu and Pb), suggesting that pyrite oxidation generated acidity and can affect the importance of pyrite as a trace metal-binding phase, mainly in response to spatial variability in tidal flooding. Besides these aerobic oxidation effects, results from a sequential extraction analyses of reactive phases evidenced that Mn oxidized phase consumption in reaction with pyrite can be also important to determine the pyritization of trace elements. Cumulative effects of these aerobic and anaerobic oxidation processes were evidenced as factors affecting the capacity of mangrove soils to act as a sink for trace metals through pyritization processes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of process parameters on greenhouse gas generation by wastewater treatment plants.

PubMed

Yerushalmi, L; Shahabadi, M Bani; Haghighat, F

2011-05-01

The effect of key process parameters on greenhouse gas (GHG) emission by wastewater treatment plants was evaluated, and the governing parameters that exhibited major effects on the overall on- and off-site GHG emissions were identified. This evaluation used aerobic, anaerobic, and hybrid anaerobic/aerobic treatment systems with food processing industry wastewater. The operating temperature of anaerobic sludge digester was identified to have the highest effect on GHG generation in the aerobic treatment system. The total GHG emissions of 2694 kg CO2e/d were increased by 72.5% with the increase of anaerobic sludge digester temperature from 20 to 40 degrees C. The operating temperature of the anaerobic reactor was the dominant controlling parameter in the anaerobic and hybrid treatment systems. Raising the anaerobic reactor's temperature from 25 to 40 degrees C increased the total GHG emissions from 5822 and 6617 kg CO2e/d by 105.6 and 96.5% in the anaerobic and hybrid treatment systems, respectively.

Biodegradation of chlorinated ethenes at a karst site in middle Tennessee

USGS Publications Warehouse

Byl, Thomas Duane; Williams, Shannon D.

2000-01-01

This report presents results of field and laboratory investigations examining the biodegradation of chlorinated ethenes in a karst aquifer contaminated with trichloroethylene (TCE). The study site, located in Middle Tennessee, was selected because of the presence of TCE degradation byproducts in the karst aquifer and available site hydrologic and chlorinated-ethene information. Additional chemical, biological, and hydrologic data were gathered to evaluate whether the occurrence of TCE degradation byproducts in the karst aquifer was the result of biodegradation within the aquifer or simply transport into the aquifer. Geochemical analysis established that sulfate-reducing conditions, essential for reductive dechlorination of chlorinated solvents, existed in parts of the contaminated karst aquifer. Other areas of the aquifer fluctuated between anaerobic and aerobic conditions and contained compounds associated with cometabolism, such as ethane, methane, ammonia, and dissolved oxygen. A large, diverse bacteria population inhabits the contaminated aquifer. Bacteria known to biodegrade TCE and other chlorinated solvents, such as sulfate-reducers, methanotrophs, and ammonia-oxidizers, were identified from karst-aquifer water using the RNA-hybridization technique. Results from microcosms using raw karst-aquifer water found that aerobic cometabolism and anaerobic reductive-dechlorination degradation processes were possible when appropriate conditions were established in the microcosms. These chemical and biological results provide circumstantial evidence that several biodegradation processes are active in the aquifer. Additional site hydrologic information was developed to determine if appropriate conditions persist long enough in the karst aquifer for these biodegradation processes to be significant. Continuous monitoring devices placed in four wells during the spring of 1998 indicated that pH, specific conductance, dissolved oxygen, and oxidation-reduction potentials changed very little in areas isolated from active ground-water flow paths. These stable areas in the karst aquifer had geochemical conditions and bacteria conducive to reductive dechlorination of chlorinated ethenes. Other areas of the karst aquifer were associated with active ground-water flow paths and fluctuated between anaerobic and aerobic conditions in response to rain events. Associated with this dynamic environment were bacteria and geochemical conditions conducive to cometabolism. In summary, multiple lines of evidence developed from chemical, biological, and hydrologic data demonstrate that a variety of biodegradation processes are active in this karst aquifer.

Effect of sludge age on methanogenic and glycogen accumulating organisms in an aerobic granular sludge process fed with methanol and acetate

PubMed Central

Pronk, M; Abbas, B; Kleerebezem, R; van Loosdrecht, M C M

2015-01-01

The influence of sludge age on granular sludge formation and microbial population dynamics in a methanol- and acetate-fed aerobic granular sludge system operated at 35°C was investigated. During anaerobic feeding of the reactor, methanol was initially converted to methane by methylotrophic methanogens. These methanogens were able to withstand the relatively long aeration periods. Lowering the anaerobic solid retention time (SRT) from 17 to 8 days enabled selective removal of the methanogens and prevented unwanted methane formation. In absence of methanogens, methanol was converted aerobically, while granule formation remained stable. At high SRT values (51 days), γ-Proteobacteria were responsible for acetate removal through anaerobic uptake and subsequent aerobic growth on storage polymers formed [so called metabolism of glycogen-accumulating organisms (GAO)]. When lowering the SRT (24 days), Defluviicoccus-related organisms (cluster II) belonging to the α-Proteobacteria outcompeted acetate consuming γ-Proteobacteria at 35°C. DNA from the Defluviicoccus-related organisms in cluster II was not extracted by the standard DNA extraction method but with liquid nitrogen, which showed to be more effective. Remarkably, the two GAO types of organisms grew separately in two clearly different types of granules. This work further highlights the potential of aerobic granular sludge systems to effectively influence the microbial communities through sludge age control in order to optimize the wastewater treatment processes. PMID:26059251

Impact of aerobic exercise on cognitive impairment and oxidative stress markers in methamphetamine-dependent patients.

PubMed

Zhang, Kai; Zhang, Qiaoyang; Jiang, Haifeng; Du, Jiang; Zhou, Chenglin; Yu, Shunying; Hashimoto, Kenji; Zhao, Min

2018-03-17

This study aimed to investigate whether 12-week moderate-intensity aerobic exercise has beneficial effects on oxidative stress markers in blood and on cognitive functions in patients who have methamphetamine dependence. Serum levels of oxidative stress markers, including total anti-oxidation capability, super oxide dismutase (SOD), catalase (CAT), and methane dicarboxylic aldehyde (MDA), were measured at baseline (all participants) and the 12-week follow-up (methamphetamine-dependent patients). Serum levels of CAT and MDA in methamphetamine-dependent patients (n = 68) were higher than those in healthy controls (n = 35) at baseline. Furthermore, the international shopping list (ISL) task scores of methamphetamine-dependent patients were significantly lower than those of the controls, indicating verbal memory deficits in methamphetamine-dependent patients. Although there were no significant interactions for all cognitive function scores, aerobic exercise improved the processing speed in methamphetamine-dependent patients. Of interest, aerobic exercise significantly attenuated a spontaneous increase in serum MDA levels in methamphetamine-dependent patients after 12-weeks of abstinence. In conclusion, this study showed that methamphetamine-dependent patients with verbal learning and memory deficits have higher serum levels of MDA, and that a 12-week aerobic exercise program may have beneficial effects on the processing speed as well as blood lipid peroxidation in methamphetamine-dependent patients. Copyright © 2018. Published by Elsevier B.V.

Effects of oxidation reduction potential in the bypass micro-aerobic sludge zone on sludge reduction for a modified oxic-settling-anaerobic process.

PubMed

Li, Kexun; Wang, Yi; Zhang, Zhongpin; Liu, Dongfang

2014-01-01

Batch experiments were conducted to determine the effect of oxidation reduction potential (ORP) on sludge reduction in a bypass micro-aerobic sludge reduction system. The system was composed of a modified oxic-settling-anaerobic process with a sludge holding tank in the sludge recycle loop. The ORPs in the micro-aerobic tanks were set at approximately +350, -90, -150, -200 and -250 mV, by varying the length of aeration time for the tanks. The results show that lower ORP result in greater sludge volume reduction, and the sludge production was reduced by 60% at the lowest ORP. In addition, low ORP caused extracellular polymer substances dissociation and slightly reduced sludge activity. Comparing the sludge backflow characteristics of the micro-aerobic tank's ORP controlled at -250 mV with that of +350 mV, the average soluble chemical oxygen (SCOD), TN and TP increased by 7, 0.4 and 2 times, median particle diameter decreased by 8.5 μm and the specific oxygen uptake rate (SOUR) decreased by 0.0043 milligram O2 per gram suspended solids per minute. For the effluent, SCOD and TN and TP fluctuated around 30, 8.7 and 0.66 mg/L, respectively. Therefore, the effective assignment of ORP in the micro-aerobic tank can remarkably reduce sludge volume and does not affect final effluent quality.

Enhanced aerobic degradation of 4-chlorophenol with iron-nickel nanoparticles

NASA Astrophysics Data System (ADS)

Shen, Wenjuan; Mu, Yi; Wang, Bingning; Ai, Zhihui; Zhang, Lizhi

2017-01-01

In this study, we demonstrate that the bimetallic iron-nickel nanoparticles (nZVIN) possessed an enhanced performance in comparison with nanoscale zero-valent iron (nZVI) on aerobic degradation of 4-chlorophenol (4-CP). The 4-CP degradation rate constant in the aerobic nZVIN process (nZVIN/Air) was 5 times that in the classic nZVI counterpart system (nZVI/Air). Both reactive oxygen species measurement and inhibition experimental results suggested that hydroxyl radicals were the major active species contributed to aerobic 4-CP degradation with nZVI, on contrast, superoxide radicals predominated the 4-CP degradation in the nZVIN/Air process. High performance liquid chromatography and gas chromatography-mass spectrometer analysis indicated the intermediates of the nZVI/Air system were p-benzoquinone and hydroquinone, which were resulted from the bond cleavage between the chlorine and carbon atom in the benzene ring by hydroxyl radicals. However, the primary intermediates of 4-CP found in the nZVIN/Air system were phenol via the direct dechlorination by superoxide radicals, accompanying with the formation of chloride ions. On the base of experimental results, a superoxide radicals mediated enhancing mechanism was proposed for the aerobic degradation of 4-CP in the nZVIN/Air system. This study provides new insight into the role of bimetallic nickel on enhancing removal of organic pollutants with nZVI.

Recycling crop residues for use in recirculating hydroponic crop production

NASA Technical Reports Server (NTRS)

Mackowiak, C. L.; Garland, J. L.; Sager, J. C.

1996-01-01

As part of bioregenerative life support feasibility testing by NASA, crop residues are being used to resupply elemental nutrients to recirculating hydroponic crop production systems. Methods for recovering nutrients from crop residues have evolved from water soaking (leaching) to rapid aerobic bioreactor processing. Leaching residues recovered the majority of elements but it also recovered significant amounts of soluble organics. The high organic content of leachates was detrimental to plant growth. Aerobic bioreactor processing reduced the organic content ten-fold, which reduced or eliminated phytotoxic effects. Wheat and potato production studies were successful using effluents from reactors having with 8- to 1-day retention times. Aerobic bioreactor effluents supplied at least half of the crops elemental mass needs in these studies. Descriptions of leachate and effluent mineral content, biomass productivity, microbial activity, and nutrient budgets for potato and wheat are presented.

Biodegradation of pulp and paper mill effluent using anaerobic followed by aerobic digestion.

PubMed

Bishnoi, Narsi R; Khumukcham, R K; Kumar, Rajender

2006-05-01

An experimental study was carried to find out the degradability of black liquor of pulp and paper mill wastewater for biomethanogenesis in continuous stirred tank reactor (CSTR) and followed by activated sludge process (ASP). Continuous stirred tank reactor was used in present study for anaerobic digestion of black liquor, while completely mixed activated sludge system was used for aerobic digestion. A maximum methane production was found up to 430 ml/day, chemical oxygen demand was reduced up to 64% and total volatile fatty acid increased up to 1500 mg/l from 975 mg/l at 7.3 pH, 37 degrees C temperature and 8 days hydraulic retention time during anaerobic digestion. In activated sludge process (aerobic digestion) chemical oxygen demand and biological oxygen demand reduction were 81% and 86% respectively at 72 hr hydraulic retention time.

Integrated catalytic wet air oxidation and biological treatment of wastewater from Vitamin B 6 production

NASA Astrophysics Data System (ADS)

Kang, Jianxiong; Zhan, Wei; Li, Daosheng; Wang, Xiaocong; Song, Jing; Liu, Dongqi

This study investigated the feasibility of coupling a catalytic wet air oxidation (CWAO), with CuO/Al 2O 3 as catalyst, and an anaerobic/aerobic biological process to treat wastewater from Vitamin B 6 production. Results showed that the CWAO enhanced the biodegradability (BOD 5/COD) from 0.10 to 0.80. The oxidized effluents with COD of 10,000 mg l -1 was subjected to subsequent continuous anaerobic/aerobic oxidation, and 99.3% of total COD removal was achieved. The quality of the effluent obtained met the discharge standards of water pollutants for pharmaceutical industry Chemical Synthesis Products Category (GB21904-2008), and thereby it implies that the integrated CWAO and anaerobic/aerobic biological treatment may offer a promising process to treat wastewater from Vitamin B 6 production.

Climate variations and the physiological basis of temperature dependent biogeography: systemic to molecular hierarchy of thermal tolerance in animals.

PubMed

Pörtner, H O

2002-08-01

The physiological mechanisms limiting and adjusting cold and heat tolerance have regained interest in the light of global warming and associated shifts in the geographical distribution of ectothermic animals. Recent comparative studies, largely carried out on marine ectotherms, indicate that the processes and limits of thermal tolerance are linked with the adjustment of aerobic scope and capacity of the whole animal as a crucial step in thermal adaptation on top of parallel adjustments at the molecular or membrane level. In accordance with Shelford's law of tolerance decreasing whole animal aerobic scope characterises the onset of thermal limitation at low and high pejus thresholds (pejus=getting worse). The drop in aerobic scope of an animal indicated by falling oxygen levels in the body fluids and or the progressively limited capacity of circulatory and ventilatory mechanisms. At high temperatures, excessive oxygen demand causes insufficient oxygen levels in the body fluids, whereas at low temperatures the aerobic capacity of mitochondria may become limiting for ventilation and circulation. Further cooling or warming beyond these limits leads to low or high critical threshold temperatures (T(c)) where aerobic scope disappears and transition to an anaerobic mode of mitochondrial metabolism and progressive insufficiency of cellular energy levels occurs. The adjustments of mitochondrial densities and their functional properties appear as a critical process in defining and shifting thermal tolerance windows. The finding of an oxygen limited thermal tolerance owing to loss of aerobic scope is in line with Taylor's and Weibel's concept of symmorphosis, which implies that excess capacity of any component of the oxygen delivery system is avoided. The present study suggests that the capacity of oxygen delivery is set to a level just sufficient to meet maximum oxygen demand between the average highs and lows of environmental temperatures. At more extreme temperatures only time limited passive survival is supported by anaerobic metabolism or the protection of molecular functions by heat shock proteins and antioxidative defence. As a corollary, the first line of thermal sensitivity is due to capacity limitations at a high level of organisational complexity, i.e. the integrated function of the oxygen delivery system, before individual, molecular or membrane functions become disturbed. These interpretations are in line with the more general consideration that, as a result of the high level of complexity of metazoan organisms compared with simple eukaryotes and then prokaryotes, thermal tolerance is reduced in metazoans. A similar sequence of sensitivities prevails within the metazoan organism, with the highest sensitivity at the organismic level and wider tolerance windows at lower levels of complexity. However, the situation is different in that loss in aerobic scope and progressive hypoxia at the organismic level define the onset of thermal limitation which then transfers to lower hierarchical levels and causes cellular and molecular disturbances. Oxygen limitation contributes to oxidative stress and, finally, denaturation or malfunction of molecular repair, e.g. during suspension of protein synthesis. The sequence of thermal tolerance limits turns into a hierarchy, ranging from systemic to cellular to molecular levels.

Aerobic Exercise Improves Mood, Cognition, and Language Function in Parkinson's Disease: Results of a Controlled Study.

PubMed

Altmann, Lori J P; Stegemöller, Elizabeth; Hazamy, Audrey A; Wilson, Jonathan P; Bowers, Dawn; Okun, Michael S; Hass, Chris J

2016-10-01

Parkinson's disease (PD) results in a range of non-motor deficits that can affect mood, cognition, and language, and many of these issues are unresponsive to pharmacological intervention. Aerobic exercise can improve mood and cognition in healthy older adults, although only a few studies have examined exercise effects on these domains in PD. The current study assesses the effects of aerobic exercise on aspects of cognition, mood, and language production in people with PD. This study compares the effects of aerobic exercise to stretch-balance training and a no-contact control group in participants with idiopathic PD. The aerobic and stretch-balance groups trained three times a week for 16 weeks, while controls continued normal activities. Outcome measures included disease severity, mood, cognition (speed of processing, memory, and executive function), and language production (picture descriptions). Cognition and language were assessed in single and dual task conditions. Depressive symptoms increased only in the control group (p<.02). Executive function improved in the aerobic exercise group only in the single task (p=.007) and declined in controls in the dual task. Completeness of picture descriptions improved significantly more in the aerobic group than in the stretch-balance group (p<.02). Aerobic exercise is a viable intervention for PD that can be protective against increased depressive symptoms, and can improve several non-motor domains, including executive dysfunction and related aspects of language production. (JINS, 2016, 22, 878-889).

Differences in the Aerobic Capacity of Flight Muscles between Butterfly Populations and Species with Dissimilar Flight Abilities

PubMed Central

Rauhamäki, Virve; Wolfram, Joy; Jokitalo, Eija; Hanski, Ilkka; Dahlhoff, Elizabeth P.

2014-01-01

Habitat loss and climate change are rapidly converting natural habitats and thereby increasing the significance of dispersal capacity for vulnerable species. Flight is necessary for dispersal in many insects, and differences in dispersal capacity may reflect dissimilarities in flight muscle aerobic capacity. In a large metapopulation of the Glanville fritillary butterfly in the Åland Islands in Finland, adults disperse frequently between small local populations. Individuals found in newly established populations have higher flight metabolic rates and field-measured dispersal distances than butterflies in old populations. To assess possible differences in flight muscle aerobic capacity among Glanville fritillary populations, enzyme activities and tissue concentrations of the mitochondrial protein Cytochrome-c Oxidase (CytOx) were measured and compared with four other species of Nymphalid butterflies. Flight muscle structure and mitochondrial density were also examined in the Glanville fritillary and a long-distance migrant, the red admiral. Glanville fritillaries from new populations had significantly higher aerobic capacities than individuals from old populations. Comparing the different species, strong-flying butterfly species had higher flight muscle CytOx content and enzymatic activity than short-distance fliers, and mitochondria were larger and more numerous in the flight muscle of the red admiral than the Glanville fritillary. These results suggest that superior dispersal capacity of butterflies in new populations of the Glanville fritillary is due in part to greater aerobic capacity, though this species has a low aerobic capacity in general when compared with known strong fliers. Low aerobic capacity may limit dispersal ability of the Glanville fritillary. PMID:24416122

Chronic aerobic exercise training attenuates aortic stiffening and endothelial dysfunction through preserving aortic mitochondrial function in aged rats.

PubMed

Gu, Qi; Wang, Bing; Zhang, Xiao-Feng; Ma, Yan-Ping; Liu, Jian-Dong; Wang, Xiao-Ze

2014-08-01

Aging leads to large vessel arterial stiffening and endothelial dysfunction, which are important determinants of cardiovascular risk. The aim of present work was to assess the effects of chronic aerobic exercise training on aortic stiffening and endothelial dysfunction in aged rats and investigate the underlying mechanism about mitochondrial function. Chronic aerobic exercise training attenuated aortic stiffening with age marked by reduced collagen concentration, increased elastin concentration and reduced pulse wave velocity (PWV), and prevented aging-related endothelial dysfunction marked by improved endothelium-mediated vascular relaxation of aortas in response to acetylcholine. Chronic aerobic exercise training abated oxidative stress and nitrosative stress in aortas of aged rats. More importantly, we found that chronic aerobic exercise training in old rats preserved aortic mitochondrial function marked by reduced reactive oxygen species (ROS) formation and mitochondrial swelling, increased ATP formation and mitochondrial DNA content, and restored activities of complexes I and III and electron-coupling capacity between complexes I and III and between complexes II and III. In addition, it was found that chronic aerobic exercise training in old rats enhanced protein expression of uncoupling protein 2 (UCP-2), peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α), manganese superoxide dismutase (Mn-SOD), aldehyde dehydrogenase 2 (ALDH-2), prohibitin (PHB) and AMP-activated kinase (AMPK) phosphorylation in aortas. In conclusion, chronic aerobic exercise training preserved mitochondrial function in aortas, which, at least in part, explained the aorta-protecting effects of exercise training in aging. Copyright © 2014 Elsevier Inc. All rights reserved.

Treatment of high salt oxidized modified starch waste water using micro-electrolysis, two-phase anaerobic aerobic and electrolysis for reuse

NASA Astrophysics Data System (ADS)

Yi, Xuenong; Wang, Yulin

2017-06-01

A combined process of micro-electrolysis, two-phase anaerobic, aerobic and electrolysis was investigated for the treatment of oxidized modified starch wastewater (OMSW). Optimum ranges for important operating variables were experimentally determined and the treated water was tested for reuse in the production process of corn starch. The optimum hydraulic retention time (HRT) of micro-electrolysis, methanation reactor, aerobic process and electrolysis process were 5, 24, 12 and 3 h, respectively. The addition of iron-carbon fillers to the acidification reactor was 200 mg/L while the best current density of electrolysis was 300 A/m2. The biodegradability was improved from 0.12 to 0.34 by micro-electrolysis. The whole treatment was found to be effective with removal of 96 % of the chemical oxygen demand (COD), 0.71 L/day of methane energy recovery. In addition, active chlorine production (15,720 mg/L) was obtained by electrolysis. The advantage of this hybrid process is that, through appropriate control of reaction conditions, effect from high concentration of salt on the treatment was avoided. Moreover, the process also produced the material needed in the production of oxidized starch while remaining emission-free and solved the problem of high process cost.

Climatic thresholds for pedogenic iron oxides under aerobic conditions: Processes and their significance in paleoclimate reconstruction

NASA Astrophysics Data System (ADS)

Long, Xiaoyong; Ji, Junfeng; Barrón, Vidal; Torrent, José

2016-10-01

Iron oxides are widely distributed across the surface of the Earth as a result of the aerobic weathering of primary Fe-bearing minerals. Pedogenic iron oxides which consist mainly of hematite (Hm), goethite (Gt), maghemite (Mgh), are often concentrated synchronously in aerobic soils under low to moderate rainfall regimes. Magnetic susceptibility (χ) and redness, which respectively reflect the content of Mgh and Hm in soils, are considered reasonable pedogenic and climatic indicators in soil taxonomy and paleorainfall reconstruction. However, under high rainfall regimes, the grain growth of Mgh and transformation to Hm, combined with the prior formation of Gt under conditions of high relative humidity (RH), can result in magnetic reduction and dramatic yellowing of soils and sediments, which explains the existence of rainfall thresholds for Mgh and Hm at a large scale even before the pedogenic environment turns anaerobic. In order to capture the rainfall thresholds for Mgh and Hm occurring under aerobic conditions, we explored a tropical transect across a granitic region where the soil color turned from red to yellow under a wide rainfall range of 900-2200 mm/yr and a corresponding mean annual RH range of 77%-85%. We observed a lower rainfall threshold of ∼1500 mm/yr and a corresponding RH ∼80% for Mgh and Hm along this transect, as well as a higher rainfall threshold of ∼1700 mm/yr and a corresponding RH of ∼81% for Gt and total pedogenic iron oxides (citrate/bicarbonate/dithionite-extractable Fe, Fed). Cross-referencing with comparable studies in temperate and subtropical regions, we noted that the rainfall or RH thresholds for Fed and Hm or Mgh likewise increase with temperature. Moreover, the different thresholds for total and individual iron oxide phase indicates that a negative correlation between chemical weathering intensity and redness or χ in sediment sequences can occur under the prevalent climate regime just between their thresholds. Finally, we developed an integrated model to interpret the sequential formation of rainfall thresholds for different pedogenic iron oxides in soils and sediments with conditions from aerobic to anaerobic.

Occurrence and Biodegradation of Nonylphenol in the Environment

PubMed Central

Mao, Zhen; Zheng, Xiao-Fei; Zhang, Yan-Qiu; Tao, Xiu-Xiang; Li, Yan; Wang, Wei

2012-01-01

Nonylphenol (NP) is an ultimate degradation product of nonylphenol polyethoxylates (NPE) that is primarily used in cleaning and industrial processes. Its widespread use has led to the wide existence of NP in various environmental matrices, such as water, sediment, air and soil. NP can be decreased by biodegradation through the action of microorganisms under aerobic or anaerobic conditions. Half-lives of biodegradation ranged from a few days to almost one hundred days. The degradation rate for NP was influenced by temperature, pH and additions of yeast extracts, surfactants, aluminum sulfate, acetate, pyruvate, lactate, manganese dioxide, ferric chloride, sodium chloride, hydrogen peroxide, heavy metals, and phthalic acid esters. Although NP is present at low concentrations in the environment, as an endocrine disruptor the risks of long-term exposure to low concentrations remain largely unknown. This paper reviews the occurrence of NP in the environment and its aerobic and anaerobic biodegradation in natural environments and sewage treatment plants, which is essential for assessing the potential risk associated with low level exposure to NP and other endocrine disruptors. PMID:22312266

Novel process combining anaerobic-aerobic digestion and ion exchange resin for full recycling of cassava stillage in ethanol fermentation.

PubMed

Yang, Xinchao; Wang, Ke; Wang, Huijun; Zhang, Jianhua; Mao, Zhonggui

2017-04-01

A novel cleaner ethanol production process has been developed. Thin stillage is treated initially by anaerobic digestion followed by aerobic digestion and then further treated by chloride anion exchange resin. This allows the fully-digested and resin-treated stillage to be completely recycled for use as process water in the next ethanol fermentation batch, which eliminates wastewater discharges and minimizes consumption of fresh water. The method was evaluated at the laboratory scale. Process parameters were very similar to those found using tap water. Maximal ethanol production rate in the fully-recycled stillage was 0.9g/L/h, which was similar to the 0.9g/L/h found with the tap water control. The consumption of fresh water was reduced from 4.1L/L (fresh water/ethanol) to zero. Compared with anaerobically-aerobically digested stillage which had not been treated with resin, the fermentation time was reduced by 28% (from 72h to 52h) and reached the level achieved with tap water. This novel process can assist in sustainable development of the ethanol industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fate and Persistence of a Pathogenic NDM-1-Positive Escherichia coli Strain in Anaerobic and Aerobic Sludge Microcosms

PubMed Central

Mantilla-Calderon, David

2017-01-01

ABSTRACT The presence of emerging biological pollutants in treated wastewater effluents has gained attention due to increased interest in water reuse. To evaluate the effectiveness of the removal of such contaminants by the conventional wastewater treatment process, the fate and decay kinetics of NDM-1-positive Escherichia coli strain PI7 and its plasmid-encoded antibiotic resistance genes (ARGs) were assessed in microcosms of anaerobic and aerobic sludge. Results showed that E. coli PI7 decayed at a significantly lower rate under anaerobic conditions. Approximate half-lives were 32.4 ± 1.4 h and 5.9 ± 0.9 h in the anaerobic and aerobic microcosms, respectively. In the aerobic microcosms, after 72 h of operation, E. coli PI7 remained detectable, but no further decay was observed. Instead, 1 in every 10,000 E. coli cells was identified to be recalcitrant to decay and persist indefinitely in the sludge. ARGs associated with the E. coli PI7 strain were detected to have transferred to other native microorganisms in the sludge or were released to the liquid fraction upon host decay. Extracellular DNA quickly degraded in the liquid fraction of the aerobic sludge. In contrast, no DNA decay was detected in the anaerobic sludge water matrix throughout the 24-h sampling period. This study suggests an increased likelihood of environmental dispersion of ARGs associated with anaerobically treated wastewater effluents and highlights the potential importance of persister cells in the dissemination of E. coli in the environment during reuse events of treated wastewater. IMPORTANCE This study examines the decay kinetics of a pathogenic and antibiotic resistant strain of Escherichia coli in microcosms simulating biological treatment units of aerobic and anaerobic sludge. The results of this study point at a significantly prolonged persistence of the E. coli and the associated antibiotic resistance gene in the anaerobic sludge. However, horizontal transfer of the plasmid encoding the antibiotic resistance gene was detected in the aerobic sludge by a cultivation method. A subpopulation of persister E. coli cells was also detected in the aerobic sludge. The findings of this study suggest potential areas of concern arising from pathogenic and antibiotic-resistant E. coli during both anaerobic and aerobic sludge treatment processes. PMID:28411227

Fate and Persistence of a Pathogenic NDM-1-Positive Escherichia coli Strain in Anaerobic and Aerobic Sludge Microcosms.

PubMed

Mantilla-Calderon, David; Hong, Pei-Ying

2017-07-01

The presence of emerging biological pollutants in treated wastewater effluents has gained attention due to increased interest in water reuse. To evaluate the effectiveness of the removal of such contaminants by the conventional wastewater treatment process, the fate and decay kinetics of NDM-1-positive Escherichia coli strain PI7 and its plasmid-encoded antibiotic resistance genes (ARGs) were assessed in microcosms of anaerobic and aerobic sludge. Results showed that E. coli PI7 decayed at a significantly lower rate under anaerobic conditions. Approximate half-lives were 32.4 ± 1.4 h and 5.9 ± 0.9 h in the anaerobic and aerobic microcosms, respectively. In the aerobic microcosms, after 72 h of operation, E. coli PI7 remained detectable, but no further decay was observed. Instead, 1 in every 10,000 E. coli cells was identified to be recalcitrant to decay and persist indefinitely in the sludge. ARGs associated with the E. coli PI7 strain were detected to have transferred to other native microorganisms in the sludge or were released to the liquid fraction upon host decay. Extracellular DNA quickly degraded in the liquid fraction of the aerobic sludge. In contrast, no DNA decay was detected in the anaerobic sludge water matrix throughout the 24-h sampling period. This study suggests an increased likelihood of environmental dispersion of ARGs associated with anaerobically treated wastewater effluents and highlights the potential importance of persister cells in the dissemination of E. coli in the environment during reuse events of treated wastewater. IMPORTANCE This study examines the decay kinetics of a pathogenic and antibiotic resistant strain of Escherichia coli in microcosms simulating biological treatment units of aerobic and anaerobic sludge. The results of this study point at a significantly prolonged persistence of the E. coli and the associated antibiotic resistance gene in the anaerobic sludge. However, horizontal transfer of the plasmid encoding the antibiotic resistance gene was detected in the aerobic sludge by a cultivation method. A subpopulation of persister E. coli cells was also detected in the aerobic sludge. The findings of this study suggest potential areas of concern arising from pathogenic and antibiotic-resistant E. coli during both anaerobic and aerobic sludge treatment processes. Copyright © 2017 Mantilla-Calderon and Hong.

The influence of pH adjustment on kinetics parameters in tapioca wastewater treatment using aerobic sequencing batch reactor system

NASA Astrophysics Data System (ADS)

Mulyani, Happy; Budianto, Gregorius Prima Indra; Margono, Kaavessina, Mujtahid

2018-02-01

The present investigation deals with the aerobic sequencing batch reactor system of tapioca wastewater treatment with varying pH influent conditions. This project was carried out to evaluate the effect of pH on kinetics parameters of system. It was done by operating aerobic sequencing batch reactor system during 8 hours in many tapioca wastewater conditions (pH 4.91, pH 7, pH 8). The Chemical Oxygen Demand (COD) and Mixed Liquor Volatile Suspended Solids (MLVSS) of the aerobic sequencing batch reactor system effluent at steady state condition were determined at interval time of two hours to generate data for substrate inhibition kinetics parameters. Values of the kinetics constants were determined using Monod and Andrews models. There was no inhibition constant (Ki) detected in all process variation of aerobic sequencing batch reactor system for tapioca wastewater treatment in this study. Furthermore, pH 8 was selected as the preferred aerobic sequencing batch reactor system condition in those ranging pH investigated due to its achievement of values of kinetics parameters such µmax = 0.010457/hour and Ks = 255.0664 mg/L COD.

Pathogen inactivation in liquid dairy manure during anaerobic and aerobic digestions

NASA Astrophysics Data System (ADS)

Biswas, S.; Pandey, P.; Castillo, A. R.; Vaddella, V. K.

2014-12-01

Controlling manure-borne pathogens such as E. coli O157:H7, Salmonella spp. and Listeria monocytogenes are crucial for protecting surface and ground water as well as mitigating risks to human health. In California dairy farms, flushing of dairy manure (mainly animal feces and urine) from freestall barns and subsequent liquid-solid manure separation is a common practice for handling animal waste. The liquid manure fraction is generally pumped into the settling ponds and it goes into aerobic and/or anaerobic lagoons for extended period of time. Considering the importance of controlling pathogens in animal waste, the objective of the study was to understand the effects of anaerobic and aerobic digestions on the survival of three human pathogens in animal waste. The pathogen inactivation was assessed at four temperatures (30, 35, 42, and 50 °C), and the relationships between temperature and pathogen decay were estimated. Results showed a steady decrease of E. coli levels in aerobic and anaerobic digestion processes over the time; however, the decay rates varied with pathogens. The effect of temperature on Salmonella spp. and Listeria monocytogenes survival was different than the E. coli survival. In thermophilic temperatures (42 and 50 °C), decay rate was considerable greater compared to the mesophilic temperatures (30 and 35°C). The E. coli log reductions at 50 °C were 2.1 in both aerobic and anaerobic digestions after 13 days of incubation. The Salmonella spp. log reductions at 50 °C were 5.5 in aerobic digestion, and 5.9 in anaerobic digestion. The Listeria monocytogenes log reductions at 50 °C were 5.0 in aerobic digestion, and 5.6 in anaerobic digestion. The log reduction of E. coli, Salmonella spp., and Listeria monocytogens at 30 °C in aerobic environment were 0.1, 4.7, and 5.6, respectively. In anaerobic environment, the corresponding reductions were 0.4, 4.3, and 5.6, respectively. We anticipate that the outcomes of the study will help improving the existing animal waste management processes to control manure-borne pathogens.

Aerobic glycolysis during brain activation: adrenergic regulation and influence of norepinephrine on astrocytic metabolism.

PubMed

Dienel, Gerald A; Cruz, Nancy F

2016-07-01

Aerobic glycolysis occurs during brain activation and is characterized by preferential up-regulation of glucose utilization compared with oxygen consumption even though oxygen level and delivery are adequate. Aerobic glycolysis is a widespread phenomenon that underlies energetics of diverse brain activities, such as alerting, sensory processing, cognition, memory, and pathophysiological conditions, but specific cellular functions fulfilled by aerobic glycolysis are poorly understood. Evaluation of evidence derived from different disciplines reveals that aerobic glycolysis is a complex, regulated phenomenon that is prevented by propranolol, a non-specific β-adrenoceptor antagonist. The metabolic pathways that contribute to excess utilization of glucose compared with oxygen include glycolysis, the pentose phosphate shunt pathway, the malate-aspartate shuttle, and astrocytic glycogen turnover. Increased lactate production by unidentified cells, and lactate dispersal from activated cells and lactate release from the brain, both facilitated by astrocytes, are major factors underlying aerobic glycolysis in subjects with low blood lactate levels. Astrocyte-neuron lactate shuttling with local oxidation is minor. Blockade of aerobic glycolysis by propranolol implicates adrenergic regulatory processes including adrenal release of epinephrine, signaling to brain via the vagus nerve, and increased norepinephrine release from the locus coeruleus. Norepinephrine has a powerful influence on astrocytic metabolism and glycogen turnover that can stimulate carbohydrate utilization more than oxygen consumption, whereas β-receptor blockade 're-balances' the stoichiometry of oxygen-glucose or -carbohydrate metabolism by suppressing glucose and glycogen utilization more than oxygen consumption. This conceptual framework may be helpful for design of future studies to elucidate functional roles of preferential non-oxidative glucose utilization and glycogen turnover during brain activation. Aerobic glycolysis, the preferential up-regulation of glucose utilization (CMRglc ) compared with oxygen consumption (CMRO2 ) during brain activation, is blocked by propranolol. Epinephrine release from the adrenal gland stimulates vagus nerve signaling to the locus coeruleus, enhancing norepinephrine release in the brain, and regulation of astrocytic and neuronal metabolism to stimulate CMRglc more than CMRO2 . Propranolol suppresses CMRglc more than CMRO2 . © 2016 International Society for Neurochemistry.

Is Maximum Food Intake in Endotherms Constrained by Net or Factorial Aerobic Scope? Lessons from the Leaf-Eared Mouse.

PubMed

Maldonado, Karin; Sabat, Pablo; Piriz, Gabriela; Bogdanovich, José M; Nespolo, Roberto F; Bozinovic, Francisco

2016-01-01

Food availability varies substantially throughout animals' lifespans, thus the ability to profit from high food levels may directly influence animal fitness. Studies exploring the link between basal metabolic rate (BMR), growth, reproduction, and other fitness traits have shown varying relationships in terms of both magnitude and direction. The diversity of results has led to the hypothesis that these relationships are modulated by environmental conditions (e.g., food availability), suggesting that the fitness consequences of a given BMR may be context-dependent. In turn, there is indirect evidence that individuals with an increased capacity for aerobic work also have a high capacity for acquiring energy from food. Surprisingly, very few studies have explored the correlation between maximum rates of energy acquisition and BMR in endotherms, and to the best of our knowledge, none have attempted to elucidate relationships between the former and aerobic capacity [e.g., maximum metabolic rate (MMR), aerobic scope (Factorial aerobic scope, FAS; Net aerobic scope, NAS)]. In this study, we measured BMR, MMR, maximum food intake (recorded under low ambient temperature and ad libitum food conditions; MFI), and estimated aerobic scope in the leaf-eared mouse ( Phyllotis darwini ). We, then, examined correlations among these variables to determine whether metabolic rates and aerobic scope are functionally correlated, and whether an increased aerobic capacity is related to a higher MFI. We found that aerobic capacity measured as NAS is positively correlated with MFI in endotherms, but with neither FAS nor BMR. Therefore, it appears plausible that the capacity for assimilating energy under conditions of abundant resources is determined adaptively by NAS, as animals with higher NAS would be promoted by selection. In theory, FAS is an invariant measurement of the extreme capacity for energy turnover in relation to resting expenditure, whereas NAS represents the maximum capacity for simultaneous aerobic processes above maintenance levels. Accordingly, in our study, FAS and NAS represent different biological variables; FAS, in contrast to NAS, may not constrain food intake. The explanations for these differences are discussed in biological and mathematical terms; further, we encourage the use of NAS rather than FAS when analyzing the aerobic capacity of animals.

Methane oxidation coupled to oxygenic photosynthesis in anoxic waters

PubMed Central

Milucka, Jana; Kirf, Mathias; Lu, Lu; Krupke, Andreas; Lam, Phyllis; Littmann, Sten; Kuypers, Marcel MM; Schubert, Carsten J

2015-01-01

Freshwater lakes represent large methane sources that, in contrast to the Ocean, significantly contribute to non-anthropogenic methane emissions to the atmosphere. Particularly mixed lakes are major methane emitters, while permanently and seasonally stratified lakes with anoxic bottom waters are often characterized by strongly reduced methane emissions. The causes for this reduced methane flux from anoxic lake waters are not fully understood. Here we identified the microorganisms and processes responsible for the near complete consumption of methane in the anoxic waters of a permanently stratified lake, Lago di Cadagno. Interestingly, known anaerobic methanotrophs could not be detected in these waters. Instead, we found abundant gamma-proteobacterial aerobic methane-oxidizing bacteria active in the anoxic waters. In vitro incubations revealed that, among all the tested potential electron acceptors, only the addition of oxygen enhanced the rates of methane oxidation. An equally pronounced stimulation was also observed when the anoxic water samples were incubated in the light. Our combined results from molecular, biogeochemical and single-cell analyses indicate that methane removal at the anoxic chemocline of Lago di Cadagno is due to true aerobic oxidation of methane fuelled by in situ oxygen production by photosynthetic algae. A similar mechanism could be active in seasonally stratified lakes and marine basins such as the Black Sea, where light penetrates to the anoxic chemocline. Given the widespread occurrence of seasonally stratified anoxic lakes, aerobic methane oxidation coupled to oxygenic photosynthesis might have an important but so far neglected role in methane emissions from lakes. PMID:25679533

Aerobic Oxidation of 5-(Hydroxymethyl)furfural Cyclic Acetal Enables Selective Furan-2,5-dicarboxylic Acid Formation with CeO2 -Supported Gold Catalyst.

PubMed

Kim, Minjune; Su, Yaqiong; Fukuoka, Atsushi; Hensen, Emiel J M; Nakajima, Kiyotaka

2018-05-14

The utilization of 5-(hydroxymethyl)furfural (HMF) for the large-scale production of essential chemicals has been largely limited by the formation of solid humin as a byproduct, which prevents the operation of stepwise batch-type and continuous flow-type processes. The reaction of HMF with 1,3-propanediol produces an HMF acetal derivative that exhibits excellent thermal stability. Aerobic oxidation of the HMF acetal with a CeO 2 -supported Au catalyst and Na 2 CO 3 in water gives a 90-95 % yield of furan 2,5-dicarboxylic acid, an increasingly important commodity chemical for the biorenewables industry, from concentrated solutions (10-20 wt %) without humin formation. The six-membered acetal ring suppresses thermal decomposition and self-polymerization of HMF in concentrated solutions. Kinetic studies supported by DFT calculations identify two crucial steps in the reaction mechanism, that is, the partial hydrolysis of the acetal into 5-formyl-2-furan carboxylic acid involving OH - and Lewis acid sites on CeO 2 , and subsequent oxidative dehydrogenation of the in situ generated hemiacetal involving Au nanoparticles. These results represent a significant advance over the current state of the art, overcoming an inherent limitation of the oxidation of HMF to an important monomer for biopolymer production. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Integrated Anaerobic-Aerobic Biodegradation of Multiple Contaminants Including Chlorinated Ethylenes, Benzene, Toluene, and Dichloromethane.

PubMed

Yoshikawa, Miho; Zhang, Ming; Toyota, Koki

2017-01-01

Complete bioremediation of soils containing multiple volatile organic compounds (VOCs) remains a challenge. To explore the possibility of complete bioremediation through integrated anaerobic-aerobic biodegradation, laboratory feasibility tests followed by alternate anaerobic-aerobic and aerobic-anaerobic biodegradation tests were performed. Chlorinated ethylenes, including tetrachloroethylene (PCE), trichloroethylene (TCE), cis -dichloroethylene ( cis -DCE), and vinyl chloride (VC), and dichloromethane (DCM) were used for anaerobic biodegradation, whereas benzene, toluene, and DCM were used for aerobic biodegradation tests. Microbial communities involved in the biodegradation tests were analyzed to characterize the major bacteria that may contribute to biodegradation. The results demonstrated that integrated anaerobic-aerobic biodegradation was capable of completely degrading the seven VOCs with initial concentration of each VOC less than 30 mg/L. Benzene and toluene were degraded within 8 days, and DCM was degraded within 20 to 27 days under aerobic conditions when initial oxygen concentrations in the headspaces of test bottles were set to 5.3% and 21.0%. Dehalococcoides sp., generally considered sensitive to oxygen, survived aerobic conditions for 28 days and was activated during the subsequent anaerobic biodegradation. However, degradation of cis -DCE was suppressed after oxygen exposure for more than 201 days, suggesting the loss of viability of Dehalococcoides sp., as they are the only known anaerobic bacteria that can completely biodegrade chlorinated ethylenes to ethylene. Anaerobic degradation of DCM following previous aerobic degradation was complete, and yet-unknown microbes may be involved in the process. The findings may provide a scientific and practical basis for the complete bioremediation of multiple contaminants in situ and a subject for further exploration.

Sub-Symptomatic Aerobic Exercise for Patients with Post-Concussion Syndrome: A Critically Appraised Topic.

PubMed

Ritter, Katrina G; Hussey, Matthew J; Valovich McLeod, Tamara C

2017-09-27

Clinical Scenario: Patients who experience prolonged concussion symptoms can be diagnosed with Post-Concussion Syndrome (PCS) when those symptoms persist past 4 weeks. Aerobic exercise protocols have been shown to be effective in improving physical and mental aspects of health. Emerging research suggests that aerobic exercise maybe useful as a treatment for PCS, where exercise allows patients to feel less isolated and more active during the recovery process. Is aerobic exercise more beneficial in reducing symptoms than current standard care in patients with prolonged symptoms or PCS lasting longer than 4 weeks? Summary of Key Findings: After a thorough literature search, 4 studies were selected relevant to the clinical question. Of the 4 studies, 1 was a randomized control trial and 3 were case series. All 4 studies investigate aerobic exercise protocol as treatment for PCS. 1-4 Three articles demonstrated a greater rate of symptom improvement from baseline assessment to follow-up after a controlled sub-symptomatic aerobic exercise program. 2-4 One study showed a decrease in symptoms in the aerobic exercise group compared to the full body stretching group. 1 Clinical Bottom Line: There is moderate evidence to support sub-symptomatic aerobic exercise as a treatment of PCS, therefore it should be considered as a clinical option for reducing PCS and prolonged concussion symptoms. A previously validated protocol, such as the Buffalo Concussion Treadmill Test, Balke Protocol, or Rating of Perceived Exertion (RPE) as mentioned in this critically appraised topic should be used to measure baseline values and treatment progression. Strength of Recommendation: Level C evidence exists that aerobic exercise protocol is more effective than the current standard of care in treating PCS.

Novel insights into anoxic/aerobic(1)/aerobic(2) biological fluidized-bed system for coke wastewater treatment by fluorescence excitation-emission matrix spectra coupled with parallel factor analysis.

PubMed

Ou, Hua-Se; Wei, Chao-Hai; Mo, Ce-Hui; Wu, Hai-Zhen; Ren, Yuan; Feng, Chun-Hua

2014-10-01

Fluorescence spectroscopy coupled with parallel factor analysis (PARAFAC) was applied to investigate the contaminant removal efficiency and fluorescent characteristic variations in a full scale coke wastewater (CWW) treatment plant with a novel anoxic/aerobic(1)/aerobic(2) (A/O(1)/O(2)) process, which combined with internal-loop fluidized-bed reactor. Routine monitoring results indicated that primary contaminants in CWW, such as phenols and free cyanide, were removed efficiently in A/O(1)/O(2) process (removal efficiency reached 99% and 95%, respectively). Three-dimensional excitation-emission matrix fluorescence spectroscopy and PARAFAC identified three fluorescent components, including two humic-like fluorescence components (C1 and C3) and one protein-like component (C2). Principal component analysis revealed that C1 and C2 correlated with COD (correlation coefficient (r)=0.782, p<0.01 and r=0.921, p<0.01), respectively) and phenols (r=0.796, p<0.01 and r=0.914, p<0.01, respectively), suggesting that C1 and C2 might be associated with the predominating aromatic contaminants in CWW. C3 correlated with mixed liquor suspended solids (r=0.863, p<0.01) in fluidized-bed reactors, suggesting that it might represent the biological dissolved organic matter. In A/O(1)/O(2) process, the fluorescence intensities of C1 and C2 consecutively decreased, indicating the degradation of aromatic contaminants. Correspondingly, the fluorescence intensity of C3 increased in aerobic(1) stage, suggesting an increase of biological dissolved organic matter. Copyright © 2014 Elsevier Ltd. All rights reserved.

The role of sulfate in aerobic granular sludge process for emerging sulfate-laden wastewater treatment.

PubMed

Xue, Weiqi; Hao, Tianwei; Mackey, Hamish R; Li, Xiling; Chan, Richard C; Chen, Guanghao

2017-11-01

Sulfate-rich wastewaters pose a major threat to mainstream wastewater treatment due to the unpreventable production of sulfide and associated shift in functional bacteria. Aerobic granular sludge could mitigate these challenges in view of its high tolerance and resilience against changes in various environmental conditions. This study aims to confirm the feasibility of aerobic granular sludge in the treatment of sulfate containing wastewater, investigate the impact of sulfate on nutrient removal and granulation, and reveal metabolic relationships in the above processes. Experiments were conducted using five sequencing batch reactors with different sulfate concentrations operated under alternating anoxic/aerobic condition. Results showed that effect of sulfate on chemical oxygen demand (COD) removal is negligible, while phosphate removal was enhanced from 12% to 87% with an increase in sulfate from 0 to 200 mg/L. However, a long acclimatization of the biomass (more than 70 days) is needed at a sulfate concentration of 500 mg/L and a total deterioration of phosphate removal at 1000 mg/L. Batch tests revealed that sulfide promoted volatile fatty acids (VFAs) uptake, producing more energy for phosphate uptake when sulfate concentrations were beneath 200 mg/L. However, sulfide detoxification became energy dominating, leaving insufficient energy for Polyhydroxyalkanoate (PHA) synthesis and phosphate uptake when sulfate content was further increased. Granulation accelerated with increasing sulfate levels by enhanced production of N-Acyl homoserine lactones (AHLs), a kind of quorum sensing (QS) auto-inducer, using S-Adenosyl Methionine (SAM) as primer. The current study demonstrates interactions among sulfate metabolism, nutrients removal and granulation, and confirms the feasibility of using the aerobic granular sludge process for sulfate-laden wastewaters treatment with low to medium sulfate content. Copyright © 2017 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rajamani, S.

The leather industry is an important export-oriented industry in India, with more than 3,000 tanneries located in different clusters. Sodium sulfide, a toxic chemical, is used in large quantities to remove hair and excess flesh from hides and skins. Most of the sodium sulfide used in the process is discharged as waste in the effluent, which causes serious environmental problems. Reduction of sulfide in the effluent is generally achieved by means of chemicals in the pretreatment system, which involves aerobic mixing using large amounts of chemicals and high energy, and generating large volumes of sludge. A simple biotechnological system thatmore » uses the residual biosludge from the secondary settling tank was developed, and the commercial-scale application established that more than 90% of the sulfide could be reduced in the primary treatment system. In addition to the reduction of sulfide, foul smells, BOD and COD are reduced to a considerable level. 3 refs., 2 figs., 1 tab.« less

Evaluating death and activity decay of Anammox bacteria during anaerobic and aerobic starvation.

PubMed

Wang, Qilin; Song, Kang; Hao, Xiaodi; Wei, Jing; Pijuan, Maite; van Loosdrecht, Mark C M; Zhao, Huijun

2018-06-01

The decreased activity (i.e. decay) of anaerobic ammonium oxidation (Anammox) bacteria during starvation can be attributed to death (i.e. decrease in the amount of viable bacteria) and activity decay (i.e. decrease in the specific activity of viable bacteria). Although they are crucial for the operation of the Anammox process, they have never been comprehensively investigated. This study for the first time experimentally assessed death and activity decay of the Anammox bacteria during 84 days' starvation stress based on ammonium removal rate, Live/Dead staining and fluorescence in-situ hybridization. The anaerobic and aerobic decay rates of Anammox bacteria were determined as 0.015 ± 0.001 d -1 and 0.028 ± 0.001 d -1 , respectively, indicating Anammox bacteria would lose their activity more quickly in the aerobic starvation than in the anaerobic starvation. The anaerobic and aerobic death rates of Anammox bacteria were measured at 0.011 ± 0.001 d -1 and 0.025 ± 0.001 d -1 , respectively, while their anaerobic and aerobic activity decay rates were determined at 0.004 ± 0.001 d -1 and 0.003 ± 0.001 d -1 , respectively. Further analysis revealed that death accounted for 73 ± 4% and 89 ± 5% of the decreased activity of Anammox bacteria during anaerobic and aerobic starvations, and activity decay was only responsible for 27 ± 4% and 11 ± 5% of the decreased Anammox activity, respectively, over the same starvation periods. These deeply shed light on the response of Anammox bacteria to the starvation stress, which would facilitate operation and optimization of the Anammox process. Copyright © 2018 Elsevier Ltd. All rights reserved.

Assessment of anaerobic blood cultures in pediatric oncology patients.

PubMed

Monsonís Cabedo, Manuel; Rives Solá, Susana; Noguera-Julian, Antoni; Urrea Ayala, Mireia; Cruz Martinez, Ofelia; Gené Giralt, Amadeu

2017-01-01

The routine use of a single aerobic bottle for blood culture in pediatric patients has become commonplace, as anaerobic bacteria are not frequently involved in clinically significant infections. The aim of this study was to assess the usefulness of routinely performing anaerobic blood cultures in pediatric oncology patients. Prospective study was conducted on pediatric (<18 years) patients affected with febrile syndrome after receiving chemotherapy for hematological or solid malignancies. Samples were inoculated into pediatric aerobic and standard anaerobic bottles (BacT/Alert automatic system). Strains were considered clinically significant, or deemed as contaminants, depending on isolation circumstances and clinical criteria. A total of 876 blood cultures from 228 patients were processed during the 21-month study period (January 2014 to September 2015). Baseline diagnosis included 143 solid tumors and 67/18 cases of leukemia/lymphoma. Bacterial growth was detected in 90 (10.2%) blood cultures for 95 different isolates, of which 62 (7.1%)/63 isolates were considered clinically significant. Among the latter, 38 (60.3%) microorganisms grew in both aerobic and anaerobic bottles, 18 (28.6%) only in aerobic bottles, and 7 (11.1%) only in anaerobic bottles. Gram-negative bacilli (33; 52.4%), mainly from the Enterobacteriaceae family, were the most frequently isolated microorganisms. Overall, only 3 out of 90 isolates (3.3%) were strict anaerobes (Propionibacterium acnes), and all of them were deemed contaminants. Strict anaerobes did not cause significant infections in febrile pediatric oncology patients, and anaerobic blood culture bottles offered no additional advantages over aerobic media. Our results suggest that routine blood cultures should be solely processed in aerobic media in this group of patients. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

L-Arginine Affects Aerobic Capacity and Muscle Metabolism in MELAS (Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-Like Episodes) Syndrome

PubMed Central

Rodan, Lance H.; Wells, Greg D.; Banks, Laura; Thompson, Sara; Schneiderman, Jane E.; Tein, Ingrid

2015-01-01

Objective To study the effects of L-arginine (L-Arg) on total body aerobic capacity and muscle metabolism as assessed by 31Phosphorus Magnetic Resonance Spectroscopy (31P-MRS) in patients with MELAS (Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-like episodes) syndrome. Methods We performed a case control study in 3 MELAS siblings (m.3243A>G tRNAleu(UUR) in MTTL1 gene) with different % blood mutant mtDNA to evaluate total body maximal aerobic capacity (VO2peak) using graded cycle ergometry and muscle metabolism using 31P-MRS. We then ran a clinical trial pilot study in MELAS sibs to assess response of these parameters to single dose and a 6-week steady-state trial of oral L-Arginine. Results At baseline (no L-Arg), MELAS had lower serum Arg (p = 0.001). On 31P-MRS muscle at rest, MELAS subjects had increased phosphocreatine (PCr) (p = 0.05), decreased ATP (p = 0.018), and decreased intracellular Mg2+ (p = 0.0002) when compared to matched controls. With L-arginine therapy, the following trends were noted in MELAS siblings on cycle ergometry: (1) increase in mean % maximum work at anaerobic threshold (AT) (2) increase in % maximum heart rate at AT (3) small increase in VO2peak. On 31P-MRS the following mean trends were noted: (1) A blunted decrease in pH after exercise (less acidosis) (2) increase in Pi/PCr ratio (ADP) suggesting increased work capacity (3) a faster half time of PCr recovery (marker of mitochondrial activity) following 5 minutes of moderate intensity exercise (4) increase in torque. Significance These results suggest an improvement in aerobic capacity and muscle metabolism in MELAS subjects in response to supplementation with L-Arg. Intramyocellular hypomagnesemia is a novel finding that warrants further study. Classification of Evidence Class III evidence that L-arginine improves aerobic capacity and muscle metabolism in MELAS subjects. Trial Registration ClinicalTrials.gov NCT01603446. PMID:25993630

Anaerobic/aerobic treatment of a petrochemical wastewater from two aromatic transformation processes by fluidized bed reactors.

PubMed

Estrada-Arriaga, Edson B; Ramirez-Camperos, Esperanza; Moeller-Chavez, Gabriela E; García-Sanchez, Liliana

2012-01-01

An integrated fluidized bed reactor (FBR) has been employed as the treatment for petrochemical industry wastewaters with high organic matter and aromatic compounds, under anaerobic and aerobic conditions. The system was operated at hydraulic residence time (HRT) of 2.7 and 2.2 h in the anaerobic and aerobic reactor, respectively. The degree of fluidization in the beds was 30%. This system showed a high performance on the removal of organic matter and aromatic compounds. At different organic loading rates (OLR), the chemical oxygen demand (COD) removal in the anaerobic reactor was close to 85% and removals of the COD up to 94% were obtained in the aerobic reactor. High removals of benzene, toluene, ethylbenzene, xylenes, styrene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene and naphthalene were achieved in this study.

Effect of aerobic pre-treatment on hydrogen and methane production in a two-stage anaerobic digestion process using food waste with different compositions.

PubMed

Rafieenia, Razieh; Girotto, Francesca; Peng, Wei; Cossu, Raffaello; Pivato, Alberto; Raga, Roberto; Lavagnolo, Maria Cristina

2017-01-01

Aerobic pre-treatment was applied prior to two-stage anaerobic digestion process. Three different food wastes samples, namely carbohydrate rich, protein rich and lipid rich, were prepared as substrates. Effect of aerobic pre-treatment on hydrogen and methane production was studied. Pre-aeration of substrates showed no positive impact on hydrogen production in the first stage. All three categories of pre-aerated food wastes produced less hydrogen compared to samples without pre-aeration. In the second stage, methane production increased for aerated protein rich and carbohydrate rich samples. In addition, the lag phase for carbohydrate rich substrate was shorter for aerated samples. Aerated protein rich substrate yielded the best results among substrates for methane production, with a cumulative production of approximately 351ml/gVS. With regard to non-aerated substrates, lipid rich was the best substrate for CH 4 production (263ml/gVS). Pre-aerated P substrate was the best in terms of total energy generation which amounted to 9.64kJ/gVS. This study revealed aerobic pre-treatment to be a promising option for use in achieving enhanced substrate conversion efficiencies and CH 4 production in a two-stage AD process, particularly when the substrate contains high amounts of proteins. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cu(II)-catalyzed esterification reaction via aerobic oxidative cleavage of C(CO)-C(alkyl) bonds.

PubMed

Ma, Ran; He, Liang-Nian; Liu, An-Hua; Song, Qing-Wen

2016-02-04

A novel Cu(II)-catalyzed aerobic oxidative esterification of simple ketones for the synthesis of esters has been developed with wide functional group tolerance. This process is assumed to go through a tandem sequence consisting of α-oxygenation/esterification/nucleophilic addition/C-C bond cleavage and carbon dioxide is released as the only byproduct.

Survival, injury and inactivation of Escherichia coli 0157:H7, salmonella and aerobic mesophilic bacteria in apple juice and cider amended with nisin-edta

USDA-ARS?s Scientific Manuscript database

For health reasons, people are consuming fresh juices or minimally processed fruit and vegetable juices, thereby, exposing themselves to the risk of foodborne illness if such juices are contaminated with bacteria pathogens. Behavior of aerobic mesophilic bacteria, Escherichia coli O157:H7 and Salmon...

Copper-catalyzed aerobic C(sp2)-H functionalization for C-N bond formation: synthesis of pyrazoles and indazoles.

PubMed

Li, Xianwei; He, Li; Chen, Huoji; Wu, Wanqing; Jiang, Huanfeng

2013-04-19

A simple, practical, and highly efficient synthesis of pyrazoles and indazoles via copper-catalyzed direct aerobic oxidative C(sp(2))-H amination has been reported herein. This process tolerated a variety of functional groups under mild conditions. Further diversification of pyrazoles was also investigated, which provided its potential for drug discovery.

Treatment of high strength distillery wastewater (cherry stillage) by integrated aerobic biological oxidation and ozonation.

PubMed

Beltrán, F J; Alvarez, P M; Rodríguez, E M; García-Araya, J F; Rivas, J

2001-01-01

The performance of integrated aerobic digestion and ozonation for the treatment of high strength distillery wastewater (i.e., cherry stillage) is reported. Experiments were conducted in laboratory batch systems operating in draw and fill mode. For the biological step, activated sludge from a municipal wastewater treatment facility was used as inoculum, showing a high degree of activity to distillery wastewater. Thus, BOD and COD overall conversions of 95% and 82% were achieved, respectively. However, polyphenol content and absorbance at 254 nm (A(254)) could not be reduced more than 35% and 15%, respectively, by means of single biological oxidation. By considering COD as substrate, the aerobic digestion process followed a Contois' model kinetics, from which the maximum specific growth rate of microorganisms (mu(max)) and the inhibition factor, beta, were then evaluated at different conditions of temperature and pH. In the combined process, the effect of a post-ozonation stage was studied. The main goals achieved by the ozonation step were the removal of polyphenols and A(254). Therefore, ozonation was shown to be an appropriate technology to aid aerobic biological oxidation in the treatment of cherry stillage.

Inverse modeling of BTEX dissolution and biodegradation at the Bemidji, MN crude-oil spill site

USGS Publications Warehouse

Essaid, H.I.; Cozzarelli, I.M.; Eganhouse, R.P.; Herkelrath, W.N.; Bekins, B.A.; Delin, G.N.

2003-01-01

The U.S. Geological Survey (USGS) solute transport and biodegradation code BIOMOC was used in conjunction with the USGS universal inverse modeling code UCODE to quantify field-scale hydrocarbon dissolution and biodegradation at the USGS Toxic Substances Hydrology Program crude-oil spill research site located near Bemidji, MN. This inverse modeling effort used the extensive historical data compiled at the Bemidji site from 1986 to 1997 and incorporated a multicomponent transport and biodegradation model. Inverse modeling was successful when coupled transport and degradation processes were incorporated into the model and a single dissolution rate coefficient was used for all BTEX components. Assuming a stationary oil body, we simulated benzene, toluene, ethylbenzene, m,p-xylene, and o-xylene (BTEX) concentrations in the oil and ground water, respectively, as well as dissolved oxygen. Dissolution from the oil phase and aerobic and anaerobic degradation processes were represented. The parameters estimated were the recharge rate, hydraulic conductivity, dissolution rate coefficient, individual first-order BTEX anaerobic degradation rates, and transverse dispersivity. Results were similar for simulations obtained using several alternative conceptual models of the hydrologic system and biodegradation processes. The dissolved BTEX concentration data were not sufficient to discriminate between these conceptual models. The calibrated simulations reproduced the general large-scale evolution of the plume, but did not reproduce the observed small-scale spatial and temporal variability in concentrations. The estimated anaerobic biodegradation rates for toluene and o-xylene were greater than the dissolution rate coefficient. However, the estimated anaerobic biodegradation rates for benzene, ethylbenzene, and m,p-xylene were less than the dissolution rate coefficient. The calibrated model was used to determine the BTEX mass balance in the oil body and groundwater plume. Dissolution from the oil body was greatest for compounds with large effective solubilities (benzene) and with large degradation rates (toluene and o-xylene). Anaerobic degradation removed 77% of the BTEX that dissolved into the water phase and aerobic degradation removed 17%. Although goodness-of-fit measures for the alternative conceptual models were not significantly different, predictions made with the models were quite variable. ?? 2003 Elsevier Science B.V. All rights reserved.

Performance of sequential anaerobic/aerobic digestion applied to municipal sewage sludge.

PubMed

Tomei, M Concetta; Rita, Sara; Mininni, Giuseppe

2011-07-01

A promising alternative to conventional single phase processing, the use of sequential anaerobic-aerobic digestion, was extensively investigated on municipal sewage sludge from a full scale wastewater treatment plant. The objective of the work was to evaluate sequential digestion performance by testing the characteristics of the digested sludge in terms of volatile solids (VS), Chemical Oxygen Demand (COD) and nitrogen reduction, biogas production, dewaterability and the content of proteins and polysaccharides. VS removal efficiencies of 32% in the anaerobic phase and 17% in the aerobic one were obtained, and similar COD removal efficiencies (29% anaerobic and 21% aerobic) were also observed. The aerobic stage was also efficient in nitrogen removal providing a decrease of the nitrogen content in the supernatant attributable to nitrification and simultaneous denitrification. Moreover, in the aerobic phase an additional marked removal of proteins and polysaccharides produced in the anaerobic phase was achieved. The sludge dewaterability was evaluated by determining the Optimal Polymer Dose (OPD) and the Capillary Suction Time (CST) and a significant positive effect due to the aerobic stage was observed. Biogas production was close to the upper limit of the range of values reported in the literature in spite of the low anaerobic sludge retention time of 15 days. From a preliminary analysis it was found that the energy demand of the aerobic phase was significantly lower than the recovered energy in the anaerobic phase and the associated additional cost was negligible in comparison to the saving derived from the reduced amount of sludge to be disposed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Limited Association Between Aerobic Fitness and Pain in Healthy Individuals: A Cross-Sectional Study.

PubMed

Jones, Matthew D; Booth, John; Taylor, Janet L; Barry, Benjamin K

2016-10-01

In healthy individuals and people with chronic pain, an inverse association between physical activity level and pain has been reported. Associations between objectively measured fitness and pain have also been found in people with chronic pain, but it is not clear whether the same relations are apparent in healthy individuals. The purpose of the present study was to examine the relation between aerobic capacity and pain in healthy individuals. Pressure pain threshold, ischemic pain tolerance, and pain ratings during ischemia were assessed and analyzed in relation to aerobic capacity in 35 healthy individuals. Correlation and multiple linear regression were used to analyze the data. Data from previous similar studies in healthy individuals and people with fibromyalgia were extracted and collated by literature review to support interpretation of the experimental data. No relation was found between aerobic capacity and any measure of pain, with the exception of a moderate inverse association between aerobic capacity and lower body pressure pain threshold in males (r = -0.58, P = 0.03) when data from male and female participants were analyzed separately. The limited association between aerobic capacity and quantitative sensory testing of pain was consistent with the data synthesis from previous studies of healthy individuals but differed from studies of people with fibromyalgia. Aerobic capacity is unrelated to pain in healthy young adults. For people with chronic pain, the negative relation between aerobic capacity and pain presumably arises from the underlying pathophysiology and/or associated behaviors of the disease process. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Renewable energy recovery through selected industrial wastes

NASA Astrophysics Data System (ADS)

Zhang, Pengchong

Typically, industrial waste treatment costs a large amount of capital, and creates environmental concerns as well. A sound alternative for treating these industrial wastes is anaerobic digestion. This technique reduces environmental pollution, and recovers renewable energy from the organic fraction of those selected industrial wastes, mostly in the form of biogas (methane). By applying anaerobic technique, selected industrial wastes could be converted from cash negative materials into economic energy feed stocks. In this study, three kinds of industrial wastes (paper mill wastes, brown grease, and corn-ethanol thin stillage) were selected, their performance in the anaerobic digestion system was studied and their applicability was investigated as well. A pilot-scale system, including anaerobic section (homogenization, pre-digestion, and anaerobic digestion) and aerobic section (activated sludge) was applied to the selected waste streams. The investigation of selected waste streams was in a gradually progressive order. For paper mill effluents, since those effluents contain a large amount of recalcitrant or toxic compounds, the anaerobic-aerobic system was used to check its treatability, including organic removal efficiency, substrate utilization rate, and methane yield. The results showed the selected effluents were anaerobically treatable. For brown grease, as it is already well known as a treatable substrate, a high rate anaerobic digester were applied to check the economic effect of this substrate, including methane yield and substrate utilization rate. These data from pilot-scale experiment have the potential to be applied to full-scale plant. For thin stillage, anaerobic digestion system has been incorporated to the traditional ethanol making process as a gate-to-gate process. The performance of anaerobic digester was applied to the gate-to-gate life-cycle analysis to estimate the energy saving and industrial cost saving in a typical ethanol plant.

Concerning the role of cell lysis-cryptic growth in anaerobic side-stream reactors: the single-cell analysis of viable, dead and lysed bacteria.

PubMed

Foladori, P; Velho, V F; Costa, R H R; Bruni, L; Quaranta, A; Andreottola, G

2015-05-01

In the Anaerobic Side-Stream Reactor (ASSR), part of the return sludge undergoes alternating aerobic and anaerobic conditions with the aim of reducing sludge production. In this paper, viability, enzymatic activity, death and lysis of bacterial cells exposed to aerobic and anaerobic conditions for 16 d were investigated at single-cell level by flow cytometry, with the objective of contributing to the understanding of the mechanisms of sludge reduction in the ASSR systems. Results indicated that total and viable bacteria did not decrease during the anaerobic phase, indicating that anaerobiosis at ambient temperature does not produce a significant cell lysis. Bacteria decay and lysis occurred principally under aerobic conditions. The aerobic decay rate of total bacteria (bTB) was considered as the rate of generation of lysed bacteria. Values of bTB of 0.07-0.11 d(-1) were measured in anaerobic + aerobic sequence. The enzymatic activity was not particularly affected by the transition from anaerobiosis to aerobiosis. Large solubilisation of COD and NH4(+) was observed only under anaerobic conditions, as a consequence of hydrolysis of organic matter, but not due to cell lysis. The observations supported the proposal of two independent mechanisms contributing equally to sludge reduction: (1) under anaerobic conditions: sludge hydrolysis of non-bacterial material, (2) under aerobic conditions: bacterial cell lysis and oxidation of released biodegradable compounds. Copyright © 2015 Elsevier Ltd. All rights reserved.

Quantification of aerobic biodegradation and volatilization rates of gasoline hydrocarbons near the water table under natural attenuation conditions

USGS Publications Warehouse

Lahvis, Matthew A.; Baehr, Arthur L.; Baker, Ronald J.

1999-01-01

Aerobic biodegradation and volatilization near the water table constitute a coupled pathway that contributes significantly to the natural attenuation of hydrocarbons at gasoline spill sites. Rates of hydrocarbon biodegradation and volatilization were quantified by analyzing vapor transport in the unsaturated zone at a gasoline spill site in Beaufort, South Carolina. Aerobic biodgradation rates decreased with distance above the water table, ranging from 0.20 to 1.5 g m−3 d−1 for toluene, from 0.24 to 0.38 g m−3 d−1for xylene, from 0.09 to 0.24 g m−3 d−1 for cyclohexene, from 0.05 to 0.22 g m−3 d−1 for ethylbenzene, and from 0.02 to 0.08 g m−3 d−1 for benzene. Rates were highest in the capillary zone, where 68% of the total hydrocarbon mass that volatilized from the water table was estimated to have been biodegraded. Hydrocarbons were nearly completely degraded within 1m above the water table. This large loss underscores the importance of aerobic biodradation in limiting the transport of hydrocarbon vapors in the unsaturated zone and implies that vapor‐plume migration to basements and other points of contact may only be significant if a source of free product is present. Furthermore, because transport of the hydrocarbon in the unsaturated zone can be limited relative to that of oxygen and carbon dioxide, soil‐gas surveys conducted at hydrocarbon‐spill sites would benefit by the inclusion of oxygen‐ and carbon‐dioxide‐gas concentration measurements. Aerobic degradation kinetics in the unsaturated zone were approximately first‐order. First‐order rate constants near the water table were highest for cyclohexene (0.21–0.65 d−1) and nearly equivalent for ethylbenzene (0.11–0.31 d−1), xylenes (0.10–0.31 d−1), toluene (0.09–0.30 d−1), and benzene (0.07–0.31 d−1). Hydrocarbon mass loss rates at the water table resulting from the coupled aerobic biodgradation and volatilization process were determined by extrapolating gas transport rates through the capillary zone. Mass loss rates from groundwater were highest for toluene (0.20–0.84 g m−2 d−1), followed by xylenes (0.12–0.69 g m−2 d−1), cyclohexene (0.05–0.15 g m−2 d−1), ethylbenzene (0.02–0.12 g m−2 d−1), and benzene (0.01–0.04 g m−2 d−1). These rates exceed predicted rates of solubilization to groundwater, demonstrating the effectiveness of aerobic biodgradation and volatilization as a combined natural attenuation pathway.

Aerobic Capacity and Cognitive Control in Elementary School-Age Children

PubMed Central

Scudder, Mark R.; Lambourne, Kate; Drollette, Eric S.; Herrmann, Stephen; Washburn, Richard; Donnelly, Joseph E.; Hillman, Charles H.

2014-01-01

Purpose The current study examined the relationship between children’s performance on the Progressive Aerobic Cardiovascular Endurance Run (PACER) subtest of the FitnessGram® and aspects of cognitive control that are believed to support academic success. Methods Hierarchical linear regression analyses were conducted on a sample of 2nd and 3rd grade children (n = 397) who completed modified versions of a flanker task and spatial n-back task to assess inhibitory control and working memory, respectively. Results Greater aerobic fitness was significantly related to shorter reaction time and superior accuracy during the flanker task, suggesting better inhibitory control and the facilitation of attention in higher fit children. A similar result was observed for the n-back task such that higher fit children exhibited more accurate target detection and discrimination performance when working memory demands were increased. Conclusion These findings support the positive association between aerobic fitness and multiple aspects of cognitive control in a large sample of children, using a widely implemented and reliable field estimate of aerobic capacity. Importantly, the current results suggest that this relationship is consistent across methods used to assess fitness, which may have important implications for extending this research to more representative samples of children in a variety of experimental contexts. PMID:24743109

Removal characteristics of pharmaceuticals and personal care products: Comparison between membrane bioreactor and various biological treatment processes.

PubMed

Park, Junwon; Yamashita, Naoyuki; Park, Chulhwi; Shimono, Tatsumi; Takeuchi, Daniel M; Tanaka, Hiroaki

2017-07-01

We investigated the concentrations of 57 target compounds in the different treatment units of various biological treatment processes in South Korea, including modified biological nutrient removal (BNR), anaerobic-anoxic-aerobic (A2O), and membrane bioreactor (MBR) systems, to elucidate the occurrence and removal fates of PPCPs in WWTPs. Biological treatment processes appeared to be most effective in eliminating most PPCPs, whereas some PPCPs were additionally removed by post-treatment. With the exception of the MBR process, the A2O system was effective for PPCPs removal. As a result, removal mechanisms were evaluated by calculating the mass balances in A2O and a lab-scale MBR process. The comparative study demonstrated that biodegradation was largely responsible for the improved removal performance found in lab-scale MBR (e.g., in removing bezafibrate, ketoprofen, and atenolol). Triclocarban, ciprofloxacin, levofloxacin and tetracycline were adsorbed in large amounts to MBR sludge. Increased biodegradability was also observed in lab-scale MBR, despite the highly adsorbable characteristics. The enhanced biodegradation potential seen in the MBR process thus likely plays a key role in eliminating highly adsorbable compounds as well as non-degradable or persistent PPCPs in other biological treatment processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Integrated horizontal-flow anaerobic and radial-flow aerobic reactors for the removal of organic matter and nitrogen from domestic sewage.

PubMed

Vieira, L G T; Fazolo, A; Zaiat, M; Foresti, E

2003-01-01

This paper presents the conception and discusses the results obtained from the operation of an integrated biological anaerobic/aerobic/anaerobic system composed of horizontal-flow anaerobic and radial-flow aerobic reactors for domestic sewage treatment. The performance of a horizontal-flow anaerobic immobilized biomass reactor, with five stages,followed by a radial-flow aerobic immobilized biomass reactor was evaluated along 22 weeks. After the 14th week, the last stage of the HAIB reactor was used as a denitrifying unit. Polyurethane foam cubic matrices with 1-cm sides were used as support for biomass immobilization in all the units. The influent domestic sewage presented mean chemical oxygen demand of 365 +/- 71 mg. 1(-1) and the temperature was 23 +/- 3degrees C. The integrated system achieved COD removal efficiency of 90% while the maximum ammonium removal efficiency was 97% in the aerobic post-treatment unit. The nitrification process was found to be better represented by first-order reactions in series model. The apparent first-order kinetic coefficient for nitrate formation was about 50 times higher than that estimated for the nitrite formation. The denitrification process was well represented by a Monod-type kinetic model. The maximum specific denitrifying rate and the half-saturation coefficient were 2.9 x 10(-4) mg NO(3)(-)-N mg(-1) VSS h(-1) and 19.4 mg NO(3)(-)-N 1(-1), respectively.

Changes in aerobic capacity and glycaemic control in response to reduced-exertion high-intensity interval training (REHIT) are not different between sedentary men and women.

PubMed

Metcalfe, Richard S; Tardif, Nicolas; Thompson, Dylan; Vollaard, Niels B J

2016-11-01

Previously it has been reported that reduced-exertion high-intensity interval training (REHIT; total training time of 3 × 10 min per week) improves maximal aerobic capacity in both sedentary men and women, but improves insulin sensitivity in men only. The aim of the present study was to determine whether there is a true sex difference in response to REHIT, or that these findings can be explained by the large interindividual variability in response inherent to all exercise training. Thirty-five sedentary participants (18 women; mean ± SD age for men and women, respectively: age, 33 ± 9 and 36 ± 9 years; body mass index, 25.1 ± 2.1 and 24.1 ± 3.5 kg·m -2 ; maximal aerobic capacity, 38.6 ± 8.3 and 31.6 ± 4.6 mL·kg -1 ·min -1 ) completed a 6-week REHIT programme consisting of eighteen 10-min unloaded cycling sessions with 1 (first session) or 2 (all other sessions) "all-out" 10-20-s sprints against a resistance of 5% of body mass. Maximal aerobic capacity and oral glucose tolerance test-derived insulin sensitivity were determined before and after training. REHIT was associated with an increase in maximal aerobic capacity (2.54 ± 0.65 vs. 2.78 ± 0.68 L·min -1 , main effect of time: p < 0.01), a trend toward reduced plasma insulin area-under-the-curve (AUC; 6.7 ± 4.8 vs. 6.1 ± 4.0 IU·min -1 ·mL -1 , p = 0.096), but no significant change in plasma glucose AUC or the Cederholm index of insulin sensitivity. Substantial interindividual variability in response to REHIT was observed for all variables, but there was no significant effect of sex. In conclusion, REHIT improves the key health marker of aerobic capacity within a minimal total training time-commitment. There is large interindividual variability in responses to REHIT, but sex differences in the responses are not apparent.

Application of dynamic models to estimate greenhouse gas emission by wastewater treatment plants of the pulp and paper industry.

PubMed

Ashrafi, Omid; Yerushalmi, Laleh; Haghighat, Fariborz

2013-03-01

Greenhouse gas (GHG) emission in wastewater treatment plants of the pulp-and-paper industry was estimated by using a dynamic mathematical model. Significant variations were shown in the magnitude of GHG generation in response to variations in operating parameters, demonstrating the limited capacity of steady-state models in predicting the time-dependent emissions of these harmful gases. The examined treatment systems used aerobic, anaerobic, and hybrid-anaerobic/aerobic-biological processes along with chemical coagulation/flocculation, anaerobic digester, nitrification and denitrification processes, and biogas recovery. The pertinent operating parameters included the influent substrate concentration, influent flow rate, and temperature. Although the average predictions by the dynamic model were only 10 % different from those of steady-state model during 140 days of operation of the examined systems, the daily variations of GHG emissions were different up to ± 30, ± 19, and ± 17 % in the aerobic, anaerobic, and hybrid systems, respectively. The variations of process variables caused fluctuations in energy generation from biogas recovery by ± 6, ± 7, and ± 4 % in the three examined systems, respectively. The lowest variations were observed in the hybrid system, showing the stability of this particular process design.

Second-Order Biomimicry: In Situ Oxidative Self-Processing Converts Copper(I)/Diamine Precursor into a Highly Active Aerobic Oxidation Catalyst.

PubMed

McCann, Scott D; Lumb, Jean-Philip; Arndtsen, Bruce A; Stahl, Shannon S

2017-04-26

A homogeneous Cu-based catalyst system consisting of [Cu(MeCN) 4 ]PF 6 , N , N '-di- tert -butylethylenediamine (DBED), and p -( N , N -dimethylamino)pyridine (DMAP) mediates efficient aerobic oxidation of alcohols. Mechanistic study of this reaction shows that the catalyst undergoes an in situ oxidative self-processing step, resulting in conversion of DBED into a nitroxyl that serves as an efficient cocatalyst for aerobic alcohol oxidation. Insights into this behavior are gained from kinetic studies, which reveal an induction period at the beginning of the reaction that correlates with the oxidative self-processing step, EPR spectroscopic analysis of the catalytic reaction mixture, which shows the buildup of the organic nitroxyl species during steady state turnover, and independent synthesis of oxygenated DBED derivatives, which are shown to serve as effective cocatalysts and eliminate the induction period in the reaction. The overall mechanism bears considerable resemblance to enzymatic reactivity. Most notable is the "oxygenase"-type self-processing step that mirrors generation of catalytic cofactors in enzymes via post-translational modification of amino acid side chains. This higher-order function within a synthetic catalyst system presents new opportunities for the discovery and development of biomimetic catalysts.

Technical note: enumeration of mesophilic aerobes in milk: evaluation of standard official protocols and Petrifilm aerobic count plates.

PubMed

Freitas, R; Nero, L A; Carvalho, A F

2009-07-01

Enumeration of mesophilic aerobes (MA) is the main quality and hygiene parameter for raw and pasteurized milk. High levels of these microorganisms indicate poor conditions in production, storage, and processing of milk, and also the presence of pathogens. Fifteen raw and 15 pasteurized milk samples were submitted for MA enumeration by a conventional plating method (using plate count agar) and Petrifilm Aerobic Count plates (3M, St. Paul, MN), followed by incubation according to 3 official protocols: IDF/ISO (incubation at 30 degrees C for 72 h), American Public Health Association (32 degrees C for 48 h), and Brazilian Ministry of Agriculture (36 degrees C for 48 h). The results were compared by linear regression and ANOVA. Considering the results from conventional methodology, good correlation indices and absence of significant differences between mean counts were observed, independent of type of milk sample (raw or pasteurized) and incubation conditions (IDF/ISO, American Public Health Association, or Ministry of Agriculture). Considering the results from Petrifilm Aerobic Count plates, good correlation indices and absence of significant differences were only observed for raw milk samples. The microbiota of pasteurized milk interfered negatively with the performance of Petrifilm Aerobic Count plates, probably because of the presence of microorganisms that poorly reduce the dye indicator of this system.

Extramitochondrial energy production in platelets.

PubMed

Ravera, Silvia; Signorello, Maria Grazia; Bartolucci, Martina; Ferrando, Sara; Manni, Lucia; Caicci, Federico; Calzia, Daniela; Panfoli, Isabella; Morelli, Alessandro; Leoncini, Giuliana

2018-05-01

Energy demand in human platelets is very high, to carry out their functions. As for most human cells, the aerobic metabolism represents the primary energy source in platelets, even though mitochondria are negligibly represented. Following the hypothesis that other structures could be involved in chemical energy production, in this work, we have investigated the functional expression of an extramitochondrial aerobic metabolism in platelets. Oximetric and luminometric analyses showed that platelets consume large amounts of oxygen and produce ATP in the presence of common respiring substrates, such as pyruvate + malate or succinate, although morphological electron microscopy analysis showed that these contain few mitochondria. However, evaluation of the anaerobic glycolytic metabolism showed that only 13% of consumed glucose was converted to lactate. Interestingly, the highest OXPHOS activity was observed in the presence of NADH, not a readily permeant respiring substrate for mitochondria. Also, oxygen consumption and ATP synthesis fuelled by NADH were not affected by atractyloside, an inhibitor of the adenine nucleotide translocase, suggesting that these processes may not be ascribed to mitochondria. Functional data were confirmed by immunofluorescence microscopy and Western blot analyses, showing a consistent expression of the β subunit of F 1 F o -ATP synthase and COXII, a subunit of Complex IV, but a low signal of translocase of the inner mitochondrial membrane (a protein not involved in OXPHOS metabolism). Interestingly, the NADH-stimulated oxygen consumption and ATP synthesis increased in the presence of the physiological platelets agonists, thrombin or collagen. Data suggest that in platelets, aerobic energy production is mainly driven by an extramitochondrial OXPHOS machinery, originated inside the megakaryocyte, and that this metabolism plays a pivotal role in platelet activation. This work represents a further example of the existence of an extramitochondrial aerobic metabolism, which can contribute to the cellular energy balance. © 2018 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

Aerobic granulation in a modified oxidation ditch with an adjustable volume intraclarifier.

PubMed

Li, Jun; Cai, Ang; Wang, Miao; Ding, Libin; Ni, Yongjiong

2014-04-01

A modified oxidation ditch (MOD) with an adjustable volume intraclarifier was proposed and used to achieve aerobic sludge granulation in continuous flow process. This MOD with working volume of 60L treated onsite wastewater from a town. Excellent aerobic granules with mean diameter of 600μm and sludge volume index (SVI) of 44mL/g were obtained in 120day. Bacterial community analysis revealed that most species from seed sludge were preserved in both MOD and granule SBR (G-SBR) except bacteria (Bacteroidetes) might be easily washed out during granulation. Some different bacterial communities were found in sludges from sequencing batch and continuous flow reactors. Presence of metal ions and inorganics in raw wastewater had positive effect on granule formation, but an adjustable volume intraclarifier for controlling selection pressure and deleting return sludge pump played a key role in aerobic sludge granulation. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Detection of anaerobic processes and microorganisms in immobilized activated sludge of a wastewater treatment plant with intense aeration].

PubMed

Litti, Iu V; Nekrasova, V K; Kulikov, N I; Siman'kova, M V; Nozhevnikova, A N

2013-01-01

Attached activated sludge from the Krasnaya Polyana (Sochi) wastewater treatment plant was studied after the reconstruction by increased aeration and water recycle, as well as by the installation of a bristle carrier for activated sludge immobilization. The activated sludge biofilms developing under conditions of intense aeration were shown to contain both aerobic and anaerobic microorganisms. Activity of a strictly anaerobic methanogenic community was revealed, which degraded organic compounds to methane, further oxidized by aerobic methanotrophs. Volatile fatty acids, the intermediates of anaerobic degradation of complex organic compounds, were used by both aerobic and anaerobic microorganisms. Anaerobic oxidation of ammonium with nitrite (anammox) and the presence of obligate anammox bacteria were revealed in attached activated sludge biofilms. Simultaneous aerobic and anaerobic degradation of organic contaminants by attached activated sludge provides for high rates of water treatment, stability of the activated sludge under variable environmental conditions, and decreased excess sludge formation.

Combined treatment of mezcal vinasses by ozonation and activated sludge.

PubMed

2017-10-18

In Mexico, mezcal production generates huge amounts of vinasses (MV) that cause negative environmental impacts. Thus, MV treatment is necessary before discharge to water bodies. Although there is no information for mezcal vinasses, similar effluents have been treated by biological processes (i.e. anaerobic and aerobic) usually complemented by oxidative chemical pretreatments (ozonation) and physico-chemical methods. In this work MV were first ozonated and followed by batch aerobic biological degradation. In the ozonation stage, organic matter removals were 4.5-11 % as COD, whereas the removal of aromatic compounds and phenols were 16-32 % and 48-83 % respectively. In the aerobic post-treatment, COD depletions up to 85 % were achieved; removals in ozone pre-treated vinasses were higher (80 to 85 %) than that of raw vinasse (69 %). It seems that ozonation preferentially attacked the recalcitrant fraction of organic matter present in the vinasses and increased its aerobic biodegradability.

A community-based approach to trials of aerobic exercise in aging and Alzheimer’s disease

PubMed Central

Vidoni, Eric D.; Van Sciver, Angela; Johnson, David K.; He, Jinghua; Honea, Robyn; Haines, Brian; Goodwin, Jami; Laubinger, M. Pat; Anderson, Heather S.; Kluding, Patricia M.; Donnelly, Joseph E.; Billinger, Sandra A.; Burns, Jeffrey M.

2012-01-01

The benefits of exercise for aging have received considerable attention in both the popular and academic press. The putative benefits of exercise for maximizing cognitive function and supporting brain health have great potential for combating Alzheimer’s disease (AD). Aerobic exercise offers a low-cost, low-risk intervention that is widely available and may have disease modifying effects. Demonstrating aerobic exercise alters the AD process would have enormous public health implications. The purpose of this paper is to a report the protocol of a current, community-based pilot study of aerobic exercise for AD to guide future investigation. This manuscript provides 1) an overview of possible benefits of exercise in those with dementia, 2) a rationale and recommendations for implementation of a community-based approach, 3) recommendation for implementation of similar study protocols, 4) unique challenges in conducting an exercise trial in AD. PMID:22903151

The Aerobic Oxidation of Bromide to Dibromine Catalyzed by Homogeneous Oxidation Catalysts and Initiated by Nitrate in Acetic Acid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Partenheimer, Walt; Fulton, John L.; Sorensen, Christina M.

A small amount of nitrate, ~0.002 molal, initiates the Co/Mn catalyzed aerobic oxidation of bromide compounds (HBr,NaBr,LiBr) to dibromine in acetic acid at room temperature. At temperatures 40oC or less , the reaction is autocatalytic. Co(II) and Mn(II) themselves and mixed with ionic bromide are known homogeneous oxidation catalysts. The reaction was discovered serendipitously when a Co/Br and Co/Mn/Br catalyst solution was prepared for the aerobic oxidation of methyaromatic compounds and the Co acetate contained a small amount of impurity i.e. nitrate. The reaction was characterized by IR, UV-VIS, MALDI and EXAFS spectroscopies and the coordination chemistry is described. Themore » reaction is inhibited by water and its rate changed by pH. The change in these variables, as well as others, are identical to those observed during homogeneous, aerobic oxidation of akylaromatics. A mechanism is proposed. Accidental addition of a small amount of nitrate compound into a Co/Mn/Br/acetic acid mixture in a large, commercial feedtank is potentially dangerous.« less

Accelerating Aerobic Sludge Granulation by Adding Dry Sewage Sludge Micropowder in Sequencing Batch Reactors

PubMed Central

Li, Jun; Liu, Jun; Wang, Danjun; Chen, Tao; Ma, Ting; Wang, Zhihong; Zhuo, Weilong

2015-01-01

Micropowder (20–250 µm) made from ground dry waste sludge from a municipal sewage treatment plant was added in a sequencing batch reactor (R2), which was fed by synthetic wastewater with acetate as carbon source. Compared with the traditional SBR (R1), aerobic sludge granulation time was shortened 15 days in R2. Furthermore, filamentous bacteria in bulking sludge were controlled to accelerate aerobic granulation and form large granules. Correspondingly, the SVI decreased from 225 mL/g to 37 mL/g. X-ray Fluorescence (XRF) analysis demonstrated that Al and Si from the micropowder were accumulated in granules. A mechanism hypotheses for the acceleration of aerobic granulation by adding dry sludge micropowder is proposed: added micropowder acts as nuclei to induce bacterial attachment; dissolved matters from the micropowder increase abruptly the organic load for starved sludge to control overgrown filamentous bacteria as a framework for aggregation; increased friction from the movement of micropowder forces the filaments which extend outwards to shrink for shaping granules. PMID:26308025

Aerobic Activity in the Healthy Elderly Is Associated with Larger Plasticity in Memory Related Brain Structures and Lower Systemic Inflammation

PubMed Central

Thielen, Jan-Willem; Kärgel, Christian; Müller, Bernhard W.; Rasche, Ina; Genius, Just; Bus, Boudewijn; Maderwald, Stefan; Norris, David G.; Wiltfang, Jens; Tendolkar, Indira

2016-01-01

Cognitive abilities decline over the time course of our life, a process, which may be mediated by brain atrophy and enhanced inflammatory processes. Lifestyle factors, such as regular physical activities have been shown to counteract those noxious processes and are assumed to delay or possibly even prevent pathological states, such as dementing disorders. Whereas the impact of lifestyle and immunological factors and their interactions on cognitive aging have been frequently studied, their effects on neural parameters as brain activation and functional connectivity are less well studied. Therefore, we investigated 32 healthy elderly individuals (60.4 ± 5.0 SD; range 52–71 years) with low or high level of self-reported aerobic physical activity at the time of testing. A higher compared to a lower level in aerobic physical activity was associated with an increased encoding related functional connectivity in an episodic memory network comprising mPFC, thalamus, hippocampus precuneus, and insula. Moreover, encoding related functional connectivity of this network was associated with decreased systemic inflammation, as measured by systemic levels of interleukin 6. PMID:28082894

Combined steam-ultrasound treatment of 2 seconds achieves significant high aerobic count and Enterobacteriaceae reduction on naturally contaminated food boxes, crates, conveyor belts, and meat knives.

PubMed

Musavian, Hanieh S; Butt, Tariq M; Larsen, Annette Baltzer; Krebs, Niels

2015-02-01

Food contact surfaces require rigorous sanitation procedures for decontamination, although these methods very often fail to efficiently clean and disinfect surfaces that are visibly contaminated with food residues and possible biofilms. In this study, the results of a short treatment (1 to 2 s) of combined steam (95°C) and ultrasound (SonoSteam) of industrial fish and meat transportation boxes and live-chicken transportation crates naturally contaminated with food and fecal residues were investigated. Aerobic counts of 5.0 to 6.0 log CFU/24 cm(2) and an Enterobacteriaceae spp. level of 2.0 CFU/24 cm(2) were found on the surfaces prior to the treatment. After 1 s of treatment, the aerobic counts were significantly (P < 0.0001) reduced, and within 2 s, reductions below the detection limit (<10 CFU) were reached. Enterobacteriaceae spp. were reduced to a level below the detection limit with only 1 s of treatment. Two seconds of steam-ultrasound treatment was also applied on two different types of plastic modular conveyor belts with hinge pins and one type of flat flexible rubber belt, all visibly contaminated with food residues. The aerobic counts of 3.0 to 5.0 CFU/50 cm(2) were significantly (P < 0.05) reduced, while Enterobacteriaceae spp. were reduced to a level below the detection limit. Industrial meat knives were contaminated with aerobic counts of 6.0 log CFU/5 cm(2) on the handle and 5.2 log CFU/14 cm(2) on the steel. The level of Enterobacteriaceae spp. contamination was approximately 2.5 log CFU on the handle and steel. Two seconds of steam-ultrasound treatment reduced the aerobic counts and Enterobacteriaceae spp. to levels below the detection limit on both handle and steel. This study shows that the steam-ultrasound treatment may be an effective replacement for disinfection processes and that it can be used for continuous disinfection at fast process lines. However, the treatment may not be able to replace efficient cleaning processes used to remove high loads of debris.

Effects of dissolved oxygen on performance and microbial community structure in a micro-aerobic hydrolysis sludge in situ reduction process.

PubMed

Niu, Tianhao; Zhou, Zhen; Shen, Xuelian; Qiao, Weimin; Jiang, Lu-Man; Pan, Wei; Zhou, Jijun

2016-03-01

A sludge process reduction activated sludge (SPRAS), with a sludge process reduction module composed of a micro-aerobic tank and a settler positioned before conventional activated sludge process, showed good performance of pollutant removal and sludge reduction. Two SPRAS systems were operated to investigate effects of micro-aeration on sludge reduction performance and microbial community structure. When dissolved oxygen (DO) concentration in the micro-aerobic tank decreased from 2.5 (SPH) to 0.5 (SPL) mg/L, the sludge reduction efficiency increased from 42.9% to 68.3%. Compared to SPH, activated sludge in SPL showed higher contents of extracellular polymeric substances and dissolved organic matter. Destabilization of floc structure in the settler, and cell lysis in the sludge process reduction module were two major reasons for sludge reduction. Illumina-MiSeq sequencing showed that microbial diversity decreased under high DO concentration. Proteobacteria, Bacteroidetes and Chloroflexi were the most abundant phyla in the SPRAS. Specific comparisons down to the class and genus level showed that fermentative, predatory and slow-growing bacteria in SPL community were more abundant than in SPH. The results revealed that micro-aeration in the SPRAS improved hydrolysis efficiency and enriched fermentative and predatory bacteria responsible for sludge reduction. Copyright © 2016 Elsevier Ltd. All rights reserved.

Relating Carbon and Nitrogen Isotope Effects to Reaction Mechanisms during Aerobic or Anaerobic Degradation of RDX (Hexahydro-1,3,5-Trinitro-1,3,5-Triazine) by Pure Bacterial Cultures

PubMed Central

Heraty, Linnea; Condee, Charles W.; Vainberg, Simon; Sturchio, Neil C.; Böhlke, J. K.; Hatzinger, Paul B.

2016-01-01

ABSTRACT Kinetic isotopic fractionation of carbon and nitrogen during RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) biodegradation was investigated with pure bacterial cultures under aerobic and anaerobic conditions. Relatively large bulk enrichments in 15N were observed during biodegradation of RDX via anaerobic ring cleavage (ε15N = −12.7‰ ± 0.8‰) and anaerobic nitro reduction (ε15N = −9.9‰ ± 0.7‰), in comparison to smaller effects during biodegradation via aerobic denitration (ε15N = −2.4‰ ± 0.2‰). 13C enrichment was negligible during aerobic RDX biodegradation (ε13C = −0.8‰ ± 0.5‰) but larger during anaerobic degradation (ε13C = −4.0‰ ± 0.8‰), with modest variability among genera. Dual-isotope ε13C/ε15N analyses indicated that the three biodegradation pathways could be distinguished isotopically from each other and from abiotic degradation mechanisms. Compared to the initial RDX bulk δ15N value of +9‰, δ15N values of the NO2− released from RDX ranged from −7‰ to +2‰ during aerobic biodegradation and from −42‰ to −24‰ during anaerobic biodegradation. Numerical reaction models indicated that N isotope effects of NO2− production were much larger than, but systematically related to, the bulk RDX N isotope effects with different bacteria. Apparent intrinsic ε15N-NO2− values were consistent with an initial denitration pathway in the aerobic experiments and more complex processes of NO2− formation associated with anaerobic ring cleavage. These results indicate the potential for isotopic analysis of residual RDX for the differentiation of degradation pathways and indicate that further efforts to examine the isotopic composition of potential RDX degradation products (e.g., NOx) in the environment are warranted. IMPORTANCE This work provides the first systematic evaluation of the isotopic fractionation of carbon and nitrogen in the organic explosive RDX during degradation by different pathways. It also provides data on the isotopic effects observed in the nitrite produced during RDX biodegradation. Both of these results could lead to better understanding of the fate of RDX in the environment and help improve monitoring and remediation technologies. PMID:27016566

Innovative low cost procedure for nutrient removal as an integrated element of a decentralised water management concept for rural areas.

PubMed

Burde, M; Rolf, F; Grabowski, F

2001-01-01

The absence of large rivers with rather high niveau of self purifying effect in parts of east Germany leads to a discharging of the effluent of wastewater treatment plants into the groundwater in many cases. One useful consequence is the idea of realisation of decentralised measures and concepts in urban water resources management concerning municipal wastewater as well as rainfall, precipitation. At the same time, only the upper soil zone--a few decimetres--is water--saturated and thus discharge effective, even when extreme rainfall takes place. Underneath, however, there generally exists an unsaturated soil zone, which is up to now a rather unexplored retardation element of the hydrologic- and substrate-cycle. Nutrient removal in small wastewater treatment plants that are emptying into ground waters is often beneficial. The presented studies optimised an inexpensive method of subsequent enhanced wastewater treatment. The developed reactor is similar to a concentrated subsoil passage. The fixed bed reactor is divided in two sections to achieve aerobic and anoxic conditions for nitrification/denitrification processes. To enhance phosphorus removal, ferrous particles are put into the aerobic zone. Two series of column tests were carried out and a technical pilot plant was built to verify the efficiency of the process. The results show that this method can be implemented successfully.

Forms of acid hydrolysis and gley formation and their role in the development of light-colored acid eluvial (Podzolic) horizons

NASA Astrophysics Data System (ADS)

Zaidel'Man, F. R.

2010-04-01

Nowadays, three processes, namely lessivage, acid hydrolysis, and gleying, are considered as responsible for the development of loamy and clayey podzolic soils. However, as was shown earlier, lessivage is not obligatory for their origin. In view of assessing the reasons for the formation of light-colored acid eluvial horizons, this article deals with the role of acid hydrolysis under aerobic conditions against the background of a percolative water regime and of two forms of gleying in the development of the horizons mentioned above. One form of gleying occurs under permanent anaerobic conditions against the background of a stagnant water regime; the other one is formed under pulsating anaerobic-aerobic conditions against the background of a stagnant-percolative water regime. As a result, three large genetically individual groups of soils are formed: nondifferentiated brown and gley, and differentiated podzolic soils on different parent rocks. The two latter forms of gleying are identical in their effects on the mineral substrates. They cause the iron removal from the soils. Among the three processes considered, the last one (gleying under a stagnant-percolative water regime) is the single reason for the leaching of most of the metals, the formation of light-colored acid eluvial horizons and their clay depletion, and for the differentiation of the soil profile.

Cost and Performance Report: Bioaugmentation for Aerobic Bioremediation of RDX-Contaminated Groundwater

DTIC Science & Technology

2015-09-01

Scenario 2 (15 yrs, $K) Cost Element Sub Element 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Total Cost Remedial Design Lagoon Area Anaerobic Bio ...Scenario 4 (15 yrs, $K) Cost Element Sub Element 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Total Cost Remedial Design Lagoon Area Anaerobic Bio ...in aerobic groundwater and typically forms large, dilute plumes that are difficult and costly to remediate using conventional technologies such as

Biodegradation of a surrogate naphthenic acid under denitrifying conditions.

PubMed

Gunawan, Yetty; Nemati, Mehdi; Dalai, Ajay

2014-03-15

Extraction of bitumen from the shallow oil sands generates extremely large volumes of waters contaminated by naphthenic acid which pose severe environmental and ecological risks. Aerobic biodegradation of NA in properly designed bioreactors has been investigated in our earlier works. In the present work, anoxic biodegradation of trans-4-methyl-1-cyclohexane carboxylic acid (trans-4MCHCA) coupled to denitrification was investigated as a potential ex situ approach for the treatment of oil sand process waters in bioreactors whereby excessive aeration cost could be eliminated, or as an in situ alternative for the treatment of these waters in anoxic stabilization ponds amended with nitrate. Using batch and continuous reactors (CSTR and biofilm), effects of NA concentration (100-750mgL(-1)), NA loading rate (up to 2607.9mgL(-1)h(-1)) and temperature (10-35°C) on biodegradation and denitrification processes were evaluated. In the batch system biodegradation of trans-4MCHCA coupled to denitrification occurred even at the highest concentration of 750mgL(-1). Consistent with the patterns reported for aerobic biodegradation, increase in initial concentration of NA led to higher biodegradation and denitrification rates and the optimum temperature was determined as 23-24°C. In the CSTR, NA removal and nitrate reduction rates passed through a maximum due to increases in NA loading rate. NA loading rate of 157.8mgL(-1)h(-1) at which maximum anoxic NA and nitrate removal rates (105.3mgL(-1)h(-1) and 144.5mgL(-1)h(-1), respectively) occurred was much higher than those reported for the aerobic alternative (NA loading and removal rates: 14.2 and 9.6mgL(-1)h(-1), respectively). In the anoxic biofilm reactor removal rates of NA and nitrate were dependent on NA loading rate in a linear fashion for the entire range of applied loading rates. The highest loading and removal rates for NA were 2607.9 and 2028.1mgL(-1)h(-1), respectively which were at least twofold higher than the values reported for the aerobic biofilm reactor. The highest nitrate removal rate coincided with maximum removal rate of NA and was 3164.7mgL(-1)h(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

Thinking big: Towards ideal strains and processes for large-scale aerobic biofuels production

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMillan, James D.; Beckham, Gregg T.

In this study, global concerns about anthropogenic climate change, energy security and independence, and environmental consequences of continued fossil fuel exploitation are driving significant public and private sector interest and financing to hasten development and deployment of processes to produce renewable fuels, as well as bio-based chemicals and materials, towards scales commensurate with current fossil fuel-based production. Over the past two decades, anaerobic microbial production of ethanol from first-generation hexose sugars derived primarily from sugarcane and starch has reached significant market share worldwide, with fermentation bioreactor sizes often exceeding the million litre scale. More recently, industrial-scale lignocellulosic ethanol plants aremore » emerging that produce ethanol from pentose and hexose sugars using genetically engineered microbes and bioreactor scales similar to first-generation biorefineries.« less

Thinking big: Towards ideal strains and processes for large-scale aerobic biofuels production

DOE PAGES

McMillan, James D.; Beckham, Gregg T.

2016-12-22

In this study, global concerns about anthropogenic climate change, energy security and independence, and environmental consequences of continued fossil fuel exploitation are driving significant public and private sector interest and financing to hasten development and deployment of processes to produce renewable fuels, as well as bio-based chemicals and materials, towards scales commensurate with current fossil fuel-based production. Over the past two decades, anaerobic microbial production of ethanol from first-generation hexose sugars derived primarily from sugarcane and starch has reached significant market share worldwide, with fermentation bioreactor sizes often exceeding the million litre scale. More recently, industrial-scale lignocellulosic ethanol plants aremore » emerging that produce ethanol from pentose and hexose sugars using genetically engineered microbes and bioreactor scales similar to first-generation biorefineries.« less

Continuous-flow synthesis of functionalized phenols by aerobic oxidation of Grignard reagents.

PubMed

He, Zhi; Jamison, Timothy F

2014-03-24

Phenols are important compounds in chemical industry. An economical and green approach to phenol preparation by the direct oxidation of aryl Grignard reagents using compressed air in continuous gas-liquid segmented flow systems is described. The process tolerates a broad range of functional groups, including oxidation-sensitive functionalities such as alkenes, amines, and thioethers. By integrating a benzyne-mediated in-line generation of arylmagnesium intermediates with the aerobic oxidation, a facile three-step, one-flow process, capable of preparing 2-functionalized phenols in a modular fashion, is established. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reduction of aerobic and lactic acid bacteria in dairy desludge using an integrated compressed CO2 and ultrasonic process.

PubMed

Overton, Tim W; Lu, Tiejun; Bains, Narinder; Leeke, Gary A

Current treatment routes are not suitable to reduce and stabilise bacterial content in some dairy process streams such as separator and bactofuge desludges which currently present a major emission problem faced by dairy producers. In this study, a novel method for the processing of desludge was developed. The new method, elevated pressure sonication (EPS), uses a combination of low frequency ultrasound (20 kHz) and elevated CO 2 pressure (50 to 100 bar). Process conditions (pressure, sonicator power, processing time) were optimised for batch and continuous EPS processes to reduce viable numbers of aerobic and lactic acid bacteria in bactofuge desludge by ≥3-log fold. Coagulation of proteins present in the desludge also occurred, causing separation of solid (curd) and liquid (whey) fractions. The proposed process offers a 10-fold reduction in energy compared to high temperature short time (HTST) treatment of milk.

Criterion Related Validity of Karate Specific Aerobic Test (KSAT).

PubMed

Chaabene, Helmi; Hachana, Younes; Franchini, Emerson; Tabben, Montassar; Mkaouer, Bessem; Negra, Yassine; Hammami, Mehrez; Chamari, Karim

2015-09-01

Karate is one the most popular combat sports in the world. Physical fitness assessment on a regular manner is important for monitoring the effectiveness of the training program and the readiness of karatekas to compete. The aim of this research was to examine the criterion related to validity of the karate specific aerobic test (KSAT) as an indicator of aerobic level of karate practitioners. Cardiorespiratory responses, aerobic performance level through both treadmill laboratory test and YoYo intermittent recovery test level 1 (YoYoIRTL1) as well as time to exhaustion in the KSAT test (TE'KSAT) were determined in a total of fifteen healthy international karatekas (i.e. karate practitioners) (means ± SD: age: 22.2 ± 4.3 years; height: 176.4 ± 7.5 cm; body mass: 70.3 ± 9.7 kg and body fat: 13.2 ± 6%). Peak heart rate obtained from KSAT represented ~99% of maximal heart rate registered during the treadmill test showing that KSAT imposes high physiological demands. There was no significant correlation between KSAT's TE and relative (mL/min kg) treadmill maximal oxygen uptake (r = 0.14; P = 0.69; [small]). On the other hand, there was a significant relationship between KSAT's TE and the velocity associated with VO2max (vVO2max) (r = 0.67; P = 0.03; [large]) as well as the velocity at VO2 corresponding to the second ventilatory threshold (vVO2 VAT) (r = 0.64; P = 0.04; [large]). Moreover, significant relationship was found between TE's KSAT and both the total distance covered and parameters of intermittent endurance measured through YoYoIRTL1. The KSAT has not proved to have indirect criterion related validity as no significant correlations have been found between TE's KSAT and treadmill VO2max. Nevertheless, as correlated to other aerobic fitness variables, KSAT can be considered as an indicator of karate specific endurance. The establishment of the criterion related validity of the KSAT requires further investigation.

Innovative dual-step management of semi-aerobic landfill in a tropical climate.

PubMed

Lavagnolo, Maria Cristina; Grossule, Valentina; Raga, Roberto

2018-04-01

Despite concerted efforts to innovate the solid waste management (SWM) system, land disposal continues to represent the most widely used technology in the treatment of urban solid waste worldwide. On the other hand, landfilling is an unavoidable step in closing the material cycle, since final residues, although minimized, need to be safely disposed of and confined. In recent years, the implementation of more sustainable landfilling aims to achieve the Final Storage Quality conditions as fast as possible. In particular, semi-aerobic landfill appears to represent an effective solution for use in the poorest economies due to lower management costs and shorter aftercare resulting from aerobic stabilisation of the waste. Nevertheless, the implementation of a semi-aerobic landfill in a tropical climate may affect the correct functioning of the plant: a lack of moisture during the dry season and heavy rainfalls during the wet season could negatively affect performance of both the degradation process, and of leachate and biogas management. This paper illustrates the results obtained through the experimentation of a potential dual-step management of semi-aerobic landfilling in a tropical climate in which composting process was reproduced during the dry season and subsequently flushing (high rainfall rate) during the wet period. Eight bioreactors specifically designed: four operated under anaerobic conditions and four under semi-aerobic conditions; half of the reactors were filled with high organic content waste, half with residual waste obtained following enhanced source segregation. The synergic effect of the subsequent phases (composting and flushing) in the semi-aerobic landfill was evaluated on the basis of both types of waste. Biogas production, leachate composition and waste stabilization were analysed during the trial and at the end of each step, and compared in view of the performance of anaerobic reactors. The results obtained underlined the effectiveness of the dual-step management evidencing how wastes reached a higher degree of stabilization and reference FSQ values for leachate were achieved over a one-year simulation period. Copyright © 2018 Elsevier Ltd. All rights reserved.

Influences of Aerobic Dance on Cognitive Performance in Adults with Schizophrenia.

PubMed

Chen, Ming-De; Kuo, Yu-Hsin; Chang, Yen-Ching; Hsu, Su-Ting; Kuo, Chang-Chih; Chang, Jyh-Jong

2016-12-01

Cognitive impairment is one of the core features of schizophrenia. This study examined the influences of an aerobic dance programme on the cognitive functions of people with schizophrenia. A quasi-experimental matched-control design was applied. The experimental group (n = 17) participated in a 60-minute aerobic dance group class three times a week for 3 months. The control group (n = 19) participated in colouring and handwriting activities. Cognitive functions were measured before and after the interventions for both groups. The intervention group experienced significant improvements in processing speed, memory and executive function, whereas no significant changes were noted in any measures in the control group. While there were no significant between-group differences, the data showed approximately medium effect sizes that favoured the intervention group in regard to processing speed (Cohen's d = 0.51), memory (d = 0.35-0.41) and the spontaneity and fluency aspects of executive function (d = 0.51). While the small sample size and lack of randomization were the primary methodological shortcomings, this study provides preliminary results supporting aerobic dance as an adjunct activity-based intervention to improve cognitive functions in people with schizophrenia. More rigorous studies are needed to validate the findings. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Contaminated environments in the subsurface and bioremediation: organic contaminants.

PubMed

Holliger, C; Gaspard, S; Glod, G; Heijman, C; Schumacher, W; Schwarzenbach, R P; Vazquez, F

1997-07-01

Due to leakages, spills, improper disposal and accidents during transport, organic compounds have become subsurface contaminants that threaten important drinking water resources. One strategy to remediate such polluted subsurface environments is to make use of the degradative capacity of bacteria. It is often sufficient to supply the subsurface with nutrients such as nitrogen and phosphorus, and aerobic treatments are still dominating. However, anaerobic processes have advantages such as low biomass production and good electron acceptor availability, and they are sometimes the only possible solution. This review will focus on three important groups of environmental organic contaminants: hydrocarbons, chlorinated and nitroaromatic compounds. Whereas hydrocarbons are oxidized and completely mineralized under anaerobic conditions in the presence of electron acceptors such as nitrate, iron, sulfate and carbon dioxide, chlorinated and nitroaromatic compounds are reductively transformed. For the aerobic often persistent polychlorinated compounds, reductive dechlorination leads to harmless products or to compounds that are aerobically degradable. The nitroaromatic compounds are first reductively transformed to the corresponding amines and can subsequently be bound to the humic fraction in an aerobic process. Such new findings and developments give hope that in the near future contaminated aquifers can efficiently be remediated, a prerequisite for a sustainable use of the precious-subsurface drinking water resources.

Coupling Spatiotemporal Community Assembly Processes to Changes in Microbial Metabolism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graham, Emily B.; Crump, Alex R.; Resch, Charles T.

Community assembly processes govern shifts in species abundances in response to environmental change, yet our understanding of assembly remains largely decoupled from ecosystem function. Here, we test hypotheses regarding assembly and function across space and time using hyporheic microbial communities as a model system. We pair sampling of two habitat types through hydrologic fluctuation with null modeling and multivariate statistics. We demonstrate that dual selective pressures assimilate to generate compositional changes at distinct timescales among habitat types, resulting in contrasting associations of Betaproteobacteria and Thaumarchaeota with selection and with seasonal changes in aerobic metabolism. Our results culminate in a conceptualmore » model in which selection from contrasting environments regulates taxon abundance and ecosystem function through time, with increases in function when oscillating selection opposes stable selective pressures. Our model is applicable within both macrobial and microbial ecology and presents an avenue for assimilating community assembly processes into predictions of ecosystem function.« less

[Diagnosis and treatment of suppurative processes caused by non-clostridial anaerobic microflora].

PubMed

Ofanesian, S S

1989-06-01

One hundred and fifty patients suffering from various purulent diseases (60 persons) and postoperative purulent complications (90 persons) caused by nonclostridial anaerobes were examined. Nonclostridial anaerobic bacteria were isolated most frequently in acute mastitis, paraproctitis, and postinfectious abscesses among patients of the first group and after appendectomy and resection of the large intestine among those of the second group. The character of the wound discharge, the location of the focus of infection, the tendency of the purulent process to form a great number of cavities and fistules, bacterioscopy of the native material, etc. help in establishing the diagnosis (before the results of bacteriological tests are obtained). Purulent processes caused by a combination of anaerobic cocci and aerobic flora take a particularly unfavourable course. Antibiotic therapy should consists of high doses of one or two antibiotics combined with metronidazole and nystatin.

Aerobic fitness and executive control of relational memory in preadolescent children.

PubMed

Chaddock, Laura; Hillman, Charles H; Buck, Sarah M; Cohen, Neal J

2011-02-01

the neurocognitive benefits of an active lifestyle in childhood have public health and educational implications, especially as children in today's technological society are becoming increasingly overweight, unhealthy, and unfit. Human and animal studies show that aerobic exercise affects both prefrontal executive control and hippocampal function. This investigation attempts to bridge these research threads by using a cognitive task to examine the relationship between aerobic fitness and executive control of relational memory in preadolescent 9- and 10-yr-old children. higher-fit and lower-fit children studied faces and houses under individual item (i.e., nonrelational) and relational encoding conditions, and the children were subsequently tested with recognition memory trials consisting of previously studied pairs and pairs of completely new items. With each subject participating in both item and relational encoding conditions, and with recognition test trials amenable to the use of both item and relational memory cues, this task afforded a challenge to the flexible use of memory, specifically in the use of appropriate encoding and retrieval strategies. Hence, the task provided a test of both executive control and memory processes. lower-fit children showed poorer recognition memory performance than higher-fit children, selectively in the relational encoding condition. No association between aerobic fitness and recognition performance was found for faces and houses studied as individual items (i.e., nonrelationally). the findings implicate childhood aerobic fitness as a factor in the ability to use effective encoding and retrieval executive control processes for relational memory material and, possibly, in the strategic engagement of prefrontal- and hippocampal-dependent systems.

Reducing aeration energy consumption in a large-scale membrane bioreactor: Process simulation and engineering application.

PubMed

Sun, Jianyu; Liang, Peng; Yan, Xiaoxu; Zuo, Kuichang; Xiao, Kang; Xia, Junlin; Qiu, Yong; Wu, Qing; Wu, Shijia; Huang, Xia; Qi, Meng; Wen, Xianghua

2016-04-15

Reducing the energy consumption of membrane bioreactors (MBRs) is highly important for their wider application in wastewater treatment engineering. Of particular significance is reducing aeration in aerobic tanks to reduce the overall energy consumption. This study proposed an in situ ammonia-N-based feedback control strategy for aeration in aerobic tanks; this was tested via model simulation and through a large-scale (50,000 m(3)/d) engineering application. A full-scale MBR model was developed based on the activated sludge model (ASM) and was calibrated to the actual MBR. The aeration control strategy took the form of a two-step cascaded proportion-integration (PI) feedback algorithm. Algorithmic parameters were optimized via model simulation. The strategy achieved real-time adjustment of aeration amounts based on feedback from effluent quality (i.e., ammonia-N). The effectiveness of the strategy was evaluated through both the model platform and the full-scale engineering application. In the former, the aeration flow rate was reduced by 15-20%. In the engineering application, the aeration flow rate was reduced by 20%, and overall specific energy consumption correspondingly reduced by 4% to 0.45 kWh/m(3)-effluent, using the present practice of regulating the angle of guide vanes of fixed-frequency blowers. Potential energy savings are expected to be higher for MBRs with variable-frequency blowers. This study indicated that the ammonia-N-based aeration control strategy holds promise for application in full-scale MBRs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Aerobic and anaerobic nitrogen transformation processes in N2-fixing cyanobacterial aggregates

PubMed Central

Klawonn, Isabell; Bonaglia, Stefano; Brüchert, Volker; Ploug, Helle

2015-01-01

Colonies of N2-fixing cyanobacteria are key players in supplying new nitrogen to the ocean, but the biological fate of this fixed nitrogen remains poorly constrained. Here, we report on aerobic and anaerobic microbial nitrogen transformation processes that co-occur within millimetre-sized cyanobacterial aggregates (Nodularia spumigena) collected in aerated surface waters in the Baltic Sea. Microelectrode profiles showed steep oxygen gradients inside the aggregates and the potential for nitrous oxide production in the aggregates' anoxic centres. 15N-isotope labelling experiments and nutrient analyses revealed that N2 fixation, ammonification, nitrification, nitrate reduction to ammonium, denitrification and possibly anaerobic ammonium oxidation (anammox) can co-occur within these consortia. Thus, N. spumigena aggregates are potential sites of nitrogen gain, recycling and loss. Rates of nitrate reduction to ammonium and N2 were limited by low internal nitrification rates and low concentrations of nitrate in the ambient water. Presumably, patterns of N-transformation processes similar to those observed in this study arise also in other phytoplankton colonies, marine snow and fecal pellets. Anoxic microniches, as a pre-condition for anaerobic nitrogen transformations, may occur within large aggregates (⩾1 mm) even when suspended in fully oxygenated waters, whereas anoxia in small aggregates (<1 to ⩾0.1 mm) may only arise in low-oxygenated waters (⩽25 μM). We propose that the net effect of aggregates on nitrogen loss is negligible in NO3−-depleted, fully oxygenated (surface) waters. In NO3−-enriched (>1.5 μM), O2-depleted water layers, for example, in the chemocline of the Baltic Sea or the oceanic mesopelagic zone, aggregates may promote N-recycling and -loss processes. PMID:25575306

Aerobic and anaerobic nitrogen transformation processes in N2-fixing cyanobacterial aggregates.

PubMed

Klawonn, Isabell; Bonaglia, Stefano; Brüchert, Volker; Ploug, Helle

2015-06-01

Colonies of N(2)-fixing cyanobacteria are key players in supplying new nitrogen to the ocean, but the biological fate of this fixed nitrogen remains poorly constrained. Here, we report on aerobic and anaerobic microbial nitrogen transformation processes that co-occur within millimetre-sized cyanobacterial aggregates (Nodularia spumigena) collected in aerated surface waters in the Baltic Sea. Microelectrode profiles showed steep oxygen gradients inside the aggregates and the potential for nitrous oxide production in the aggregates' anoxic centres. (15)N-isotope labelling experiments and nutrient analyses revealed that N(2) fixation, ammonification, nitrification, nitrate reduction to ammonium, denitrification and possibly anaerobic ammonium oxidation (anammox) can co-occur within these consortia. Thus, N. spumigena aggregates are potential sites of nitrogen gain, recycling and loss. Rates of nitrate reduction to ammonium and N(2) were limited by low internal nitrification rates and low concentrations of nitrate in the ambient water. Presumably, patterns of N-transformation processes similar to those observed in this study arise also in other phytoplankton colonies, marine snow and fecal pellets. Anoxic microniches, as a pre-condition for anaerobic nitrogen transformations, may occur within large aggregates (⩾1 mm) even when suspended in fully oxygenated waters, whereas anoxia in small aggregates (<1 to ⩾0.1 mm) may only arise in low-oxygenated waters (⩽25 μM). We propose that the net effect of aggregates on nitrogen loss is negligible in NO(3)(-)-depleted, fully oxygenated (surface) waters. In NO(3)(-)-enriched (>1.5 μM), O(2)-depleted water layers, for example, in the chemocline of the Baltic Sea or the oceanic mesopelagic zone, aggregates may promote N-recycling and -loss processes.

Biotic and abiotic degradation of CL-20 and RDX in soils.

PubMed

Crocker, Fiona H; Thompson, Karen T; Szecsody, James E; Fredrickson, Herbert L

2005-01-01

The caged cyclic nitramine 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) is a new explosive that has the potential to replace existing military explosives, but little is known about its environmental toxicity, transport, and fate. We quantified and compared the aerobic environmental fate of CL-20 to the widely used cyclic nitramine explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in surface and subsurface soil microcosms. Soil-free controls and biologically attenuated soil controls were used to separate abiotic processes from biologically mediated processes. Both abiotic and biological processes significantly degraded CL-20 in all soils examined. Apparent abiotic, first-order degradation rates (k) for CL-20 were not significantly different between soil-free controls (0.018 < k < 0.030 d(-1)) and biologically attenuated soil controls (0.003 < k < 0.277 d(-1)). The addition of glucose to biologically active soil microcosms significantly increased CL-20 degradation rates (0.068 < k < 1.22 d(-1)). Extents of mineralization of (14)C-CL-20 to (14)CO(2) in biologically active soil microcosms were 41.1 to 55.7%, indicating that the CL-20 cage was broken, since all carbons are part of the heterocyclic cage. Under aerobic conditions, abiotic degradation rates of RDX were generally slower (0 < k < 0.032 d(-1)) than abiotic CL-20 degradation rates. In biologically active soil microcosms amended with glucose aerobic RDX degradation rates varied between 0.010 and 0.474 d(-1). Biodegradation was a key factor in determining the environmental fate of RDX, while a combination of biotic and abiotic processes was important with CL-20. Our data suggest that CL-20 should be less recalcitrant than RDX in aerobic soils.

Reliability, Validity and Usefulness of 30–15 Intermittent Fitness Test in Female Soccer Players

PubMed Central

Čović, Nedim; Jelešković, Eldin; Alić, Haris; Rađo, Izet; Kafedžić, Erduan; Sporiš, Goran; McMaster, Daniel T.; Milanović, Zoran

2016-01-01

PURPOSE: The aim of this study was to examine the reliability, validity and usefulness of the 30–15IFT in competitive female soccer players. METHODS: Seventeen elite female soccer players participated in the study. A within subject test-retest study design was utilized to assess the reliability of the 30–15 intermittent fitness test (IFT). Seven days prior to 30–15IFT, subjects performed a continuous aerobic running test (CT) under laboratory conditions to assess the criterion validity of the 30–15IFT. End running velocity (VCT and VIFT), peak heart rate (HRpeak) and maximal oxygen consumption (VO2max) were collected and/or estimated for both tests. RESULTS: VIFT (ICC = 0.91; CV = 1.8%), HRpeak (ICC = 0.94; CV = 1.2%), and VO2max (ICC = 0.94; CV = 1.6%) obtained from the 30–15IFT were all deemed highly reliable (p > 0.05). Pearson product moment correlations between the CT and 30–15IFT for VO2max, HRpeak and end running velocity were large (r = 0.67, p = 0.013), very large (r = 0.77, p = 0.02) and large (r = 0.57, p = 0.042), respectively. CONCLUSION: Current findings suggest that the 30–15IFT is a valid and reliable intermittent aerobic fitness test of elite female soccer players. The findings have also provided practitioners with evidence to support the accurate detection of meaningful individual changes in VIFT of 0.5 km/h (1 stage) and HRpeak of 2 bpm. This information may assist coaches in monitoring “real” aerobic fitness changes to better inform training of female intermittent team sport athletes. Lastly, coaches could use the 30–15IFT as a practical alternative to laboratory based assessments to assess and monitor intermittent aerobic fitness changes in their athletes. PMID:27909408

Evaluation of aerobic co-composting of penicillin fermentation fungi residue with pig manure on penicillin degradation, microbial population dynamics and composting maturity.

PubMed

Zhang, Zhenhua; Zhao, Juan; Yu, Cigang; Dong, Shanshan; Zhang, Dini; Yu, Ran; Wang, Changyong; Liu, Yan

2015-12-01

Improper treatment of penicillin fermentation fungi residue (PFFR), one of the by-products of penicillin production process, may result in environmental pollution due to the high concentration of penicillin. Aerobic co-composting of PFFR with pig manure was determined to degrade penicillin in PFFR. Results showed that co-composting of PFFR with pig manure can significantly reduce the concentration of penicillin in PFFR, make the PFFR-compost safer as organic fertilizer for soil application. More than 99% of penicillin in PFFR were removed after 7-day composting. PFFR did not affect the composting process and even promote the activity of the microorganisms in the compost. Quantitative PCR (qPCR) indicated that the bacteria and actinomycetes number in the AC samples were 40-80% higher than that in the pig-manure compost (CK) samples in the same composting phases. This research indicated that the aerobic co-composting was a feasible PFFR treatment method. Copyright © 2015 Elsevier Ltd. All rights reserved.

[EPIDEMIOLOGICAL, CLINICAL AND MICROBIOLOGICAL FINDINGS IN WOMEN WITH AEROBIC VAGINITIS].

PubMed

Dermendjiev, T; Pehlivanov, B; Hadjieva, K; Stanev, S

2015-01-01

Aerobic vaginitis (AV) is an alterarion of the normal lactobacillic flora accompanied by signs of inflammation, presence of mainly aerobic microorganisms from intestinal commensals or other aerobic pathogens. Clinical symptoms may vary by type and intensity and are marked by a high tendency for recurrence and chronification. Inflammation and ulcerations in AV could increase the risk of contracting HIV or other sexually transmitted infections. The aim is to study some epidemiological, clinical and microbiological features of the aerobic vaginitis in patients of the specialized Obstetric and Gynecological Clinic in Plovdiv, Bulgaria. In a retrospective research 4687 vaginal smears have been gathered in Microbiological laboratory at "St. George" Hospital - Plovdiv. We used clinical, microbiological and statistical methods. Information processing is performed by variation, alternative, correlation and graphical analysis using specialized package SPSS v13.0. The overall prevalence rate of AV in the studied population is 11.77%. The levels of prevalence of AV in pregnant and non-pregnant women are respectively 13.08% and 4.34%. The highest frequency of AV is in the age group 21-30 years (32.3%). The results show a marked association between Escherichia coli and the cases of AV (p < 0.001). AV is a common cause of vaginal symptoms in patients of specialized ambulatory outpatient. One in ten women with vaginal complaints suffers from AV Streptococcus agalactiae and Escherichia coli are most often isolated aerobic microorganisms.

Formation of aerobic granular sludge and the influence of the pH on sludge characteristics in a SBR fed with brewery/bottling plant wastewater.

PubMed

Stes, Hannah; Aerts, Sven; Caluwé, Michel; Dobbeleers, Thomas; Wuyts, Sander; Kiekens, Filip; D'aes, Jolien; De Langhe, Piet; Dries, Jan

2018-05-01

A laboratory-scale sequencing batch reactor (SBR) was operated for 450 days to assess aerobic granule formation when treating brewery/bottling plant wastewater by consistent application of a feast/famine regime. The experiment was divided into three major periods according to the different operational conditions: (I) no pH control and strong fluctuations in organic loading rate (OLR) (1.18 ± 0.25 kgCOD·(m 3 ·day) -1 ), (II) pH control and aeration control strategy to reduce OLR fluctuations (1.45 ± 0.65 kgCOD·(m 3 ·day) -1 ) and (III) no pH control and stable OLR (1.42 ± 0.18 kgCOD·(m 3 ·day) -1 ). Aerobic granule formation was successful after 80 days and maintained during the subsequent 380 days. The aerobic granular sludge was characterized by SVI 5 and SVI 30 values below 60 mL.g -1 and dominated by granular, dense structures. An oxygen uptake rate based aeration control strategy insured endogenous respiration at the end of the aerobic phase, resulting in stable SBR operation when the influent composition fluctuated. The quantitative polymerase chain reaction results show no significant enrichment of Accumulibacter or Competibacter during the granulation process. The 16S rRNA sequencing results indicate enrichment of other, possibly important species during aerobic granule formation while treating brewery wastewaters.

Anaerobic Copper Toxicity and Iron-Sulfur Cluster Biogenesis in Escherichia coli.

PubMed

Tan, Guoqiang; Yang, Jing; Li, Tang; Zhao, Jin; Sun, Shujuan; Li, Xiaokang; Lin, Chuxian; Li, Jianghui; Zhou, Huaibin; Lyu, Jianxin; Ding, Huangen

2017-08-15

While copper is an essential trace element in biology, pollution of groundwater from copper has become a threat to all living organisms. Cellular mechanisms underlying copper toxicity, however, are still not fully understood. Previous studies have shown that iron-sulfur proteins are among the primary targets of copper toxicity in Escherichia coli under aerobic conditions. Here, we report that, under anaerobic conditions, iron-sulfur proteins in E. coli cells are even more susceptible to copper in medium. Whereas addition of 0.2 mM copper(II) chloride to LB (Luria-Bertani) medium has very little or no effect on iron-sulfur proteins in wild-type E. coli cells under aerobic conditions, the same copper treatment largely inactivates iron-sulfur proteins by blocking iron-sulfur cluster biogenesis in the cells under anaerobic conditions. Importantly, proteins that do not have iron-sulfur clusters (e.g., fumarase C and cysteine desulfurase) in E. coli cells are not significantly affected by copper treatment under aerobic or anaerobic conditions, indicating that copper may specifically target iron-sulfur proteins in cells. Additional studies revealed that E. coli cells accumulate more intracellular copper under anaerobic conditions than under aerobic conditions and that the elevated copper content binds to the iron-sulfur cluster assembly proteins IscU and IscA, which effectively inhibits iron-sulfur cluster biogenesis. The results suggest that the copper-mediated inhibition of iron-sulfur proteins does not require oxygen and that iron-sulfur cluster biogenesis is the primary target of anaerobic copper toxicity in cells. IMPORTANCE Copper contamination in groundwater has become a threat to all living organisms. However, cellular mechanisms underlying copper toxicity have not been fully understood up to now. The work described here reveals that iron-sulfur proteins in Escherichia coli cells are much more susceptible to copper in medium under anaerobic conditions than they are under aerobic conditions. Under anaerobic conditions, E. coli cells accumulate excess intracellular copper, which specifically targets iron-sulfur proteins by blocking iron-sulfur cluster biogenesis. Since iron-sulfur proteins are involved in diverse and vital physiological processes, inhibition of iron-sulfur cluster biogenesis by copper disrupts multiple cellular functions and ultimately inhibits cell growth. The results from this study illustrate a new interplay between intracellular copper toxicity and iron-sulfur cluster biogenesis in bacterial cells under anaerobic conditions. Copyright © 2017 American Society for Microbiology.

Anaerobic Copper Toxicity and Iron-Sulfur Cluster Biogenesis in Escherichia coli

PubMed Central

Tan, Guoqiang; Yang, Jing; Li, Tang; Zhao, Jin; Sun, Shujuan; Li, Xiaokang; Lin, Chuxian; Li, Jianghui; Zhou, Huaibin

2017-01-01

ABSTRACT While copper is an essential trace element in biology, pollution of groundwater from copper has become a threat to all living organisms. Cellular mechanisms underlying copper toxicity, however, are still not fully understood. Previous studies have shown that iron-sulfur proteins are among the primary targets of copper toxicity in Escherichia coli under aerobic conditions. Here, we report that, under anaerobic conditions, iron-sulfur proteins in E. coli cells are even more susceptible to copper in medium. Whereas addition of 0.2 mM copper(II) chloride to LB (Luria-Bertani) medium has very little or no effect on iron-sulfur proteins in wild-type E. coli cells under aerobic conditions, the same copper treatment largely inactivates iron-sulfur proteins by blocking iron-sulfur cluster biogenesis in the cells under anaerobic conditions. Importantly, proteins that do not have iron-sulfur clusters (e.g., fumarase C and cysteine desulfurase) in E. coli cells are not significantly affected by copper treatment under aerobic or anaerobic conditions, indicating that copper may specifically target iron-sulfur proteins in cells. Additional studies revealed that E. coli cells accumulate more intracellular copper under anaerobic conditions than under aerobic conditions and that the elevated copper content binds to the iron-sulfur cluster assembly proteins IscU and IscA, which effectively inhibits iron-sulfur cluster biogenesis. The results suggest that the copper-mediated inhibition of iron-sulfur proteins does not require oxygen and that iron-sulfur cluster biogenesis is the primary target of anaerobic copper toxicity in cells. IMPORTANCE Copper contamination in groundwater has become a threat to all living organisms. However, cellular mechanisms underlying copper toxicity have not been fully understood up to now. The work described here reveals that iron-sulfur proteins in Escherichia coli cells are much more susceptible to copper in medium under anaerobic conditions than they are under aerobic conditions. Under anaerobic conditions, E. coli cells accumulate excess intracellular copper, which specifically targets iron-sulfur proteins by blocking iron-sulfur cluster biogenesis. Since iron-sulfur proteins are involved in diverse and vital physiological processes, inhibition of iron-sulfur cluster biogenesis by copper disrupts multiple cellular functions and ultimately inhibits cell growth. The results from this study illustrate a new interplay between intracellular copper toxicity and iron-sulfur cluster biogenesis in bacterial cells under anaerobic conditions. PMID:28576762

New process for alleviation of membrane fouling of modified hybrid MBR system for advanced domestic wastewater treatment.

PubMed

Shuo, Liu; Baozhen, Wang; Hongjun, Han; Yanping, Liu

2008-01-01

A pilot-scale hybrid membrane bioreactor using a submerged flat panel membrane was designed and applied for advanced treatment of domestic wastewater. The new process adapted to the hybrid membrane bioreactor exhibits substantial decrease in membrane fouling and much easier cleaning. In this study, the new process configurations including the addition of anoxic/anaerobic zones, the package of synthetic fibrous fabric carrier for biofilm attached growth, activated sludge recycling and modified dosage of polished diatomite with high activity and multi-functions were investigated to select the optimal operational parameters for the hybrid membrane bioreactor system. The carrier package in the aerobic zone contributed 3.65 g/L (maximum) of fixed biomass to the system, thus reducing the suspended biomass, and has decreased the membrane cleaning cycle remarkably. The operation performance at the sludge recycle rate 0, 100%, 200% and 300% showed that, the trans-membrane pressure of flat panel membrane declined sharply with the increase of sludge recycling rate within a certain range, and 200% was decided to be optimal for in the membrane bioreactor system. EPS concentration in each sludge recycling rate was 135 mg/L, 92 mg/L, 68 mg/L and 55 mg/L respectively. The addition of anoxic and anaerobic zones degraded some large molecular organic compounds, which facilitated the biodegradation and removal of organic substances in aerobic zone. The modified dosage of polished diatomite has played a major important role for both preventing of membrane from fouling and its much easier cleaning when it formed. Copyright (c) IWA Publishing 2008.

Aggregate Size and Architecture Determine Microbial Activity Balance for One-Stage Partial Nitritation and Anammox ▿

PubMed Central

Vlaeminck, Siegfried E.; Terada, Akihiko; Smets, Barth F.; De Clippeleir, Haydée; Schaubroeck, Thomas; Bolca, Selin; Demeestere, Lien; Mast, Jan; Boon, Nico; Carballa, Marta; Verstraete, Willy

2010-01-01

Aerobic ammonium-oxidizing bacteria (AerAOB) and anoxic ammonium-oxidizing bacteria (AnAOB) cooperate in partial nitritation/anammox systems to remove ammonium from wastewater. In this process, large granular microbial aggregates enhance the performance, but little is known about granulation so far. In this study, three suspended-growth oxygen-limited autotrophic nitrification-denitrification (OLAND) reactors with different inoculation and operation (mixing and aeration) conditions, designated reactors A, B, and C, were used. The test objectives were (i) to quantify the AerAOB and AnAOB abundance and the activity balance for the different aggregate sizes and (ii) to relate aggregate morphology, size distribution, and architecture putatively to the inoculation and operation of the three reactors. A nitrite accumulation rate ratio (NARR) was defined as the net aerobic nitrite production rate divided by the anoxic nitrite consumption rate. The smallest reactor A, B, and C aggregates were nitrite sources (NARR, >1.7). Large reactor A and C aggregates were granules capable of autonomous nitrogen removal (NARR, 0.6 to 1.1) with internal AnAOB zones surrounded by an AerAOB rim. Around 50% of the autotrophic space in these granules consisted of AerAOB- and AnAOB-specific extracellular polymeric substances. Large reactor B aggregates were thin film-like nitrite sinks (NARR, <0.5) in which AnAOB were not shielded by an AerAOB layer. Voids and channels occupied 13 to 17% of the anoxic zone of AnAOB-rich aggregates (reactors B and C). The hypothesized granulation pathways include granule replication by division and budding and are driven by growth and/or decay based on species-specific physiology and by hydrodynamic shear and mixing. PMID:19948857

Artificial neural network modelling for organic and total nitrogen removal of aerobic granulation under steady-state condition.

PubMed

Gong, H; Pishgar, R; Tay, J H

2018-04-27

Aerobic granulation is a recent technology with high level of complexity and sensitivity to environmental and operational conditions. Artificial neural networks (ANNs), computational tools capable of describing complex non-linear systems, are the best fit to simulate aerobic granular bioreactors. In this study, two feedforward backpropagation ANN models were developed to predict chemical oxygen demand (Model I) and total nitrogen removal efficiencies (Model II) of aerobic granulation technology under steady-state condition. Fundamentals of ANN models and the steps to create them were briefly reviewed. The models were respectively fed with 205 and 136 data points collected from laboratory-, pilot-, and full-scale studies on aerobic granulation technology reported in the literature. Initially, 60%, 20%, and 20%, and 80%, 10%, and 10% of the points in the corresponding datasets were randomly chosen and used for training, testing, and validation of Model I, and Model II, respectively. Overall coefficient of determination (R 2 ) value and mean squared error (MSE) of the two models were initially 0.49 and 15.5, and 0.37 and 408, respectively. To improve the model performance, two data division methods were used. While one method is generic and potentially applicable to other fields, the other can only be applied to modelling the performance of aerobic granular reactors. R 2 value and MSE were improved to 0.90 and 2.54, and 0.81 and 121.56, respectively, after applying the new data division methods. The results demonstrated that ANN-based models were capable simulation approach to predict a complicated process like aerobic granulation.

The effects on the microbiological condition of product of carcass dressing, cooling, and portioning processes at a poultry packing plant.

PubMed

Gill, C O; Moza, L F; Badoni, M; Barbut, S

2006-07-15

The log mean numbers of aerobes, coliforms, Escherichia coli and presumptive staphylococci plus listerias on chicken carcasses and carcass portions at various stages of processing at a poultry packing plant were estimated from the numbers of those bacteria recovered from groups of 25 randomly selected product units. The fractions of listerias in the presumptive staphylococci plus listerias groups of organisms were also estimated. Samples were obtained from carcasses by excising a strip of skin measuring approximately 5 x 2 cm(2) from a randomly selected site on each selected carcass, or by rinsing each selected carcass portion. The log mean numbers of aerobes, coliforms, E. coli and presumptive staphylococci plus listerias on carcasses after scalding at 58 degrees C and plucking were about 4.4, 2.5, 2.2 and 1.4 log cfu/cm(2), respectively. The numbers of bacteria on eviscerated carcasses were similar. After the series of operations for removing the crop, lungs, kidneys and neck, the numbers of aerobes were about 1 log unit less than on eviscerated carcasses, but the numbers of the other bacteria were not substantially reduced. After cooling in water, the numbers of coliforms and E. coli were about 1 log unit less and the numbers of presumptive staphylococci plus listerias were about 0.5 log unit less than the numbers on dressed carcasses, but the numbers of aerobes were not reduced. The numbers of aerobes were 1 log unit more on boneless breasts, and 0.5 log units more on skin-on thighs and breasts that had been tumbled with brine than on cooled carcasses; and presumptive staphylococci plus listerias were 0.5 log unit more on thighs than on cooled carcasses. Otherwise the numbers of bacteria on the product were not substantially affected by processing. Listerias were <20% of the presumptive staphylococci plus listerias group of organisms recovered from product at each point in the process except after breasts were tumbled with brine, when >40% of the organisms were listerias.

Nitric oxide is an obligate bacterial nitrification intermediate produced by hydroxylamine oxidoreductase.

PubMed

Caranto, Jonathan D; Lancaster, Kyle M

2017-08-01

Ammonia (NH 3 )-oxidizing bacteria (AOB) emit substantial amounts of nitric oxide (NO) and nitrous oxide (N 2 O), both of which contribute to the harmful environmental side effects of large-scale agriculture. The currently accepted model for AOB metabolism involves NH 3 oxidation to nitrite (NO 2 - ) via a single obligate intermediate, hydroxylamine (NH 2 OH). Within this model, the multiheme enzyme hydroxylamine oxidoreductase (HAO) catalyzes the four-electron oxidation of NH 2 OH to NO 2 - We provide evidence that HAO oxidizes NH 2 OH by only three electrons to NO under both anaerobic and aerobic conditions. NO 2 - observed in HAO activity assays is a nonenzymatic product resulting from the oxidation of NO by O 2 under aerobic conditions. Our present study implies that aerobic NH 3 oxidation by AOB occurs via two obligate intermediates, NH 2 OH and NO, necessitating a mediator of the third enzymatic step.

Devitalization of bacterial and parasitic germs in sewage sludge during aerobic digestion under laboratory conditions.

PubMed

Juris, P; Plachý, P; Lauková, A

1995-05-01

The survival of 8 bacterial species (Pseudomonas sp., Salmonella sp., Enterobacteriae, Streptococcus sp., Escherichia coli) was detected in municipal sewage sludge up to 37 hours of mesophilic aerobic digestion under laboratory conditions. The model strain Enterococcus faecium CCM 4231 survived almost twice as long as the above-mentioned isolates. Similar findings, regarding the viability of the microorganisms studied, were also determined during thermophilic aerobic digestion of municipal sewage sludges. The final reduction in the total count of bacteria was not directly dependent on the temperature during aerobic digestion. It may be supposed that E. faecium CCM 4231 strain as a bacteriocin-producing strain with a broad antimicrobial spectrum, inoculated into the sludges, could inhibit the growth of microorganisms in the sludges by the way of its bacteriocin activity. Studying the effect of aerobic digestion on the viability of helminth eggs, the observed negative effect of higher temperatures was more expressive in comparison with bacterial strains. During thermophilic digestion process all helminth eggs (Ascaris suum, Toxocara canis) were devitalized. All eggs of T. canis were killed in experiments under mesophilic temperature. However, 32% of nonembryonated A. suum eggs remained viable.

Fact-finding survey of actual garbage discharged from dormitory and its biological anaerobic-aerobic treatment.

PubMed

Imai, T; Ukita, M; Sekine, M; Fukagawa, M; Nakanishi, H

2000-01-01

The objective of this study is to find a possibility of complete treatment of garbage and resource recovery (production of methane from available utility of carbon resource in garbage) by biological treatment process. As the first step, a fact-finding survey of actual garbage discharged from the dormitory of the Ube National College of Technology (equivalent to 300 population) was carried out. Second, the combined biological anaerobic-aerobic treatment, i.e. combination of upflow anaerobic sludge blanket (UASB) process and aerobic membrane bioreactor (AMB) process, was applied to the garbage treatment. The applicability and efficiency of this system were investigated in this study. The survey results showed that the composition and quantity of garbage from a student dormitory changed slightly during a week due to the change of the menu, however, they remained almost unchanged during the entire experimental period. The experimental results showed high biodegradability of the garbage, and demonstrated its suitability for methane production. The soluble nitrogen removal was high: over 97%. No excess sludge was wasted from the system. A high treatment efficiency of simultaneous organic carbon and nitrogen was obtained. The possibility of complete treatment of garbage with this process has been positively demonstrated by this study.

Second-Order Biomimicry: In Situ Oxidative Self-Processing Converts Copper(I)/Diamine Precursor into a Highly Active Aerobic Oxidation Catalyst

PubMed Central

2017-01-01

A homogeneous Cu-based catalyst system consisting of [Cu(MeCN)4]PF6, N,N′-di-tert-butylethylenediamine (DBED), and p-(N,N-dimethylamino)pyridine (DMAP) mediates efficient aerobic oxidation of alcohols. Mechanistic study of this reaction shows that the catalyst undergoes an in situ oxidative self-processing step, resulting in conversion of DBED into a nitroxyl that serves as an efficient cocatalyst for aerobic alcohol oxidation. Insights into this behavior are gained from kinetic studies, which reveal an induction period at the beginning of the reaction that correlates with the oxidative self-processing step, EPR spectroscopic analysis of the catalytic reaction mixture, which shows the buildup of the organic nitroxyl species during steady state turnover, and independent synthesis of oxygenated DBED derivatives, which are shown to serve as effective cocatalysts and eliminate the induction period in the reaction. The overall mechanism bears considerable resemblance to enzymatic reactivity. Most notable is the “oxygenase”-type self-processing step that mirrors generation of catalytic cofactors in enzymes via post-translational modification of amino acid side chains. This higher-order function within a synthetic catalyst system presents new opportunities for the discovery and development of biomimetic catalysts. PMID:28470049

Copper-catalyzed aerobic decarboxylative sulfonylation of cinnamic acids with sodium sulfinates: stereospecific synthesis of (E)-alkenyl sulfones.

PubMed

Jiang, Qing; Xu, Bin; Jia, Jing; Zhao, An; Zhao, Yu-Rou; Li, Ying-Ying; He, Na-Na; Guo, Can-Cheng

2014-08-15

A copper-catalyzed aerobic decarboxylative sulfonylation of alkenyl carboxylic acids with sodium sulfinates is developed. This study offers a new and expedient strategy for stereoselective synthesis of (E)-alkenyl sulfones that are widely present in biologically active natural products and therapeutic agents. Moreover, the transformation is proposed to proceed via a radical process and exhibits a broad substrate scope and good functional group tolerance.

Aerobic oxidation in nanomicelles of aryl alkynes, in water at room temperature.

PubMed

Handa, Sachin; Fennewald, James C; Lipshutz, Bruce H

2014-03-24

On the basis of the far higher solubility of oxygen gas inside the hydrocarbon core of nanomicelles, metal and peroxide free aerobic oxidation of aryl alkynes to β-ketosulfones has been achieved in water at room temperature. Many examples are offered that illustrate broad functional group tolerance. The overall process is environmentally friendly, documented by the associated low E Factors. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Eosin Y-catalyzed visible-light-mediated aerobic oxidative cyclization of N,N-dimethylanilines with maleimides.

PubMed

Liang, Zhongwei; Xu, Song; Tian, Wenyan; Zhang, Ronghua

2015-01-01

A novel and simple strategy for the efficient synthesis of the corresponding tetrahydroquinolines from N,N-dimethylanilines and maleimides using visible light in an air atmosphere in the presence of Eosin Y as a photocatalyst has been developed. The metal-free protocol involves aerobic oxidative cyclization via sp(3) C-H bond functionalization process to afford good yields in a one-pot procedure under mild conditions.

Extracellular protein analysis of activated sludge and their functions in wastewater treatment plant by shotgun proteomics.

PubMed

Zhang, Peng; Shen, Yu; Guo, Jin-Song; Li, Chun; Wang, Han; Chen, You-Peng; Yan, Peng; Yang, Ji-Xiang; Fang, Fang

2015-07-10

In this work, proteins in extracellular polymeric substances extracted from anaerobic, anoxic and aerobic sludges of wastewater treatment plant (WWTP) were analyzed to probe their origins and functions. Extracellular proteins in WWTP sludges were identified using shotgun proteomics, and 130, 108 and 114 proteins in anaerobic, anoxic and aerobic samples were classified, respectively. Most proteins originated from cell and cell part, and their most major molecular functions were catalytic activity and binding activity. The results exhibited that the main roles of extracellular proteins in activated sludges were multivalence cations and organic molecules binding, as well as in catalysis and degradation. The catalytic activity proteins were more widespread in anaerobic sludge compared with those in anoxic and aerobic sludges. The structure difference between anaerobic and aerobic sludges could be associated with their catalytic activities proteins. The results also put forward a relation between the macro characteristics of activated sludges and micro functions of extracellular proteins in biological wastewater treatment process.

Climate change in fish: effects of respiratory constraints on optimal life history and behaviour.

PubMed

Holt, Rebecca E; Jørgensen, Christian

2015-02-01

The difference between maximum metabolic rate and standard metabolic rate is referred to as aerobic scope, and because it constrains performance it is suggested to constitute a key limiting process prescribing how fish may cope with or adapt to climate warming. We use an evolutionary bioenergetics model for Atlantic cod (Gadus morhua) to predict optimal life histories and behaviours at different temperatures. The model assumes common trade-offs and predicts that optimal temperatures for growth and fitness lie below that for aerobic scope; aerobic scope is thus a poor predictor of fitness at high temperatures. Initially, warming expands aerobic scope, allowing for faster growth and increased reproduction. Beyond the optimal temperature for fitness, increased metabolic requirements intensify foraging and reduce survival; oxygen budgeting conflicts thus constrain successful completion of the life cycle. The model illustrates how physiological adaptations are part of a suite of traits that have coevolved. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Cryptic oxygen cycling in anoxic marine zones.

PubMed

Garcia-Robledo, Emilio; Padilla, Cory C; Aldunate, Montserrat; Stewart, Frank J; Ulloa, Osvaldo; Paulmier, Aurélien; Gregori, Gerald; Revsbech, Niels Peter

2017-08-01

Oxygen availability drives changes in microbial diversity and biogeochemical cycling between the aerobic surface layer and the anaerobic core in nitrite-rich anoxic marine zones (AMZs), which constitute huge oxygen-depleted regions in the tropical oceans. The current paradigm is that primary production and nitrification within the oxic surface layer fuel anaerobic processes in the anoxic core of AMZs, where 30-50% of global marine nitrogen loss takes place. Here we demonstrate that oxygenic photosynthesis in the secondary chlorophyll maximum (SCM) releases significant amounts of O 2 to the otherwise anoxic environment. The SCM, commonly found within AMZs, was dominated by the picocyanobacteria Prochlorococcus spp. Free O 2 levels in this layer were, however, undetectable by conventional techniques, reflecting a tight coupling between O 2 production and consumption by aerobic processes under apparent anoxic conditions. Transcriptomic analysis of the microbial community in the seemingly anoxic SCM revealed the enhanced expression of genes for aerobic processes, such as nitrite oxidation. The rates of gross O 2 production and carbon fixation in the SCM were found to be similar to those reported for nitrite oxidation, as well as for anaerobic dissimilatory nitrate reduction and sulfate reduction, suggesting a significant effect of local oxygenic photosynthesis on Pacific AMZ biogeochemical cycling.

The Analysis of a Microbial Community in the UV/O3-Anaerobic/Aerobic Integrated Process for Petrochemical Nanofiltration Concentrate (NFC) Treatment by 454-Pyrosequencing.

PubMed

Wei, Chao; He, Wenjie; Wei, Li; Li, Chunying; Ma, Jun

2015-01-01

In this study, high-throughput pyrosequencing was applied on the analysis of the microbial community of activated sludge and biofilm in a lab-scale UV/O3- anaerobic/aerobic (A/O) integrated process for the treatment of petrochemical nanofiltration concentrate (NFC) wastewater. NFC is a type of saline wastewater with low biodegradability. From the anaerobic activated sludge (Sample A) and aerobic biofilm (Sample O), 59,748 and 51,231 valid sequence reads were obtained, respectively. The dominant phylotypes related to the metabolism of organic compounds, polycyclic aromatic hydrocarbon (PAH) biodegradation, assimilation of carbon from benzene, and the biodegradation of nitrogenous organic compounds were detected as genus Clostridium, genera Pseudomonas and Stenotrophomonas, class Betaproteobacteria, and genus Hyphomicrobium. Furthermore, the nitrite-oxidising bacteria Nitrospira, nitrite-reducing and sulphate-oxidising bacteria (NR-SRB) Thioalkalivibrio were also detected. In the last twenty operational days, the total Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) removal efficiencies on average were 64.93% and 62.06%, respectively. The removal efficiencies of ammonia nitrogen and Total Nitrogen (TN) on average were 90.51% and 75.11% during the entire treatment process.

The Analysis of a Microbial Community in the UV/O3-Anaerobic/Aerobic Integrated Process for Petrochemical Nanofiltration Concentrate (NFC) Treatment by 454-Pyrosequencing

PubMed Central

Wei, Chao; He, Wenjie; Wei, Li; Li, Chunying; Ma, Jun

2015-01-01

In this study, high-throughput pyrosequencing was applied on the analysis of the microbial community of activated sludge and biofilm in a lab-scale UV/O3- anaerobic/aerobic (A/O) integrated process for the treatment of petrochemical nanofiltration concentrate (NFC) wastewater. NFC is a type of saline wastewater with low biodegradability. From the anaerobic activated sludge (Sample A) and aerobic biofilm (Sample O), 59,748 and 51,231 valid sequence reads were obtained, respectively. The dominant phylotypes related to the metabolism of organic compounds, polycyclic aromatic hydrocarbon (PAH) biodegradation, assimilation of carbon from benzene, and the biodegradation of nitrogenous organic compounds were detected as genus Clostridium, genera Pseudomonas and Stenotrophomonas, class Betaproteobacteria, and genus Hyphomicrobium. Furthermore, the nitrite-oxidising bacteria Nitrospira, nitrite-reducing and sulphate-oxidising bacteria (NR-SRB) Thioalkalivibrio were also detected. In the last twenty operational days, the total Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) removal efficiencies on average were 64.93% and 62.06%, respectively. The removal efficiencies of ammonia nitrogen and Total Nitrogen (TN) on average were 90.51% and 75.11% during the entire treatment process. PMID:26461260

The Effectiveness of Aerobic Exercise in Improving Peripheral Nerve Functions in Type 2 Diabetes Mellitus: An Evidence Based Case Report.

PubMed

Mirtha, Listya Tresnanti; Permatahati, Viandini

2018-01-01

peripheral neuropathy is known as one of most common complication in diabetes mellitus type 2 patient. This complication is caused by uncontrolled condition of blood glucose level in long periode. Regular physical activity in moderate to high intensity is beneficial in management of diabetes mellitus. This report aimed to know the effectiveness of aerobic exercise in causing improved peripheral functions in type 2 diabetes mellitus. literature searching using several related keywords in Medline®, Pubmed®, and Cochrane library, following inclusion and exclusion criteria. Dixit et al suggested that a heart rate intensity of 40-60% aerobic exercise of 30-45 min duration per session for eight weeks suggest an important impact in controlling diabetic peripheral neuropathy. Kluding PM et al suggested that significantly improved selected measures of peripheral nerve function ("worst" pain levels and MNSI score), glycemic control (HbA1c), and resting heart rate. the studies showed significant benefit of aerobic exercise, despite the short duration of exercise being used as intervention towards improvement in peripheral nerve function. However, further studies with large samples and longer duration of intervention are needed to confirm the finding.

Cardioprotective effects of early and late aerobic exercise training in experimental pulmonary arterial hypertension.

PubMed

Moreira-Gonçalves, Daniel; Ferreira, Rita; Fonseca, Hélder; Padrão, Ana Isabel; Moreno, Nuno; Silva, Ana Filipa; Vasques-Nóvoa, Francisco; Gonçalves, Nádia; Vieira, Sara; Santos, Mário; Amado, Francisco; Duarte, José Alberto; Leite-Moreira, Adelino F; Henriques-Coelho, Tiago

2015-11-01

Clinical studies suggest that aerobic exercise can exert beneficial effects in pulmonary arterial hypertension (PAH), but the underlying mechanisms are largely unknown. We compared the impact of early or late aerobic exercise training on right ventricular function, remodeling and survival in experimental PAH. Male Wistar rats were submitted to normal cage activity (SED), exercise training in early (EarlyEX) and in late stage (LateEX) of PAH induced by monocrotaline (MCT, 60 mg/kg). Both exercise interventions resulted in improved cardiac function despite persistent right pressure-overload, increased exercise tolerance and survival, with greater benefits in EarlyEX+MCT. This was accompanied by improvements in the markers of cardiac remodeling (SERCA2a), neurohumoral activation (lower endothelin-1, brain natriuretic peptide and preserved vascular endothelial growth factor mRNA), metabolism and mitochondrial oxidative stress in both exercise interventions. EarlyEX+MCT provided additional improvements in fibrosis, tumor necrosis factor-alpha/interleukin-10 and brain natriuretic peptide mRNA, and beta/alpha myosin heavy chain protein expression. The present study demonstrates important cardioprotective effects of aerobic exercise in experimental PAH, with greater benefits obtained when exercise training is initiated at an early stage of the disease.

Activity and diversity of aerobic methanotrophs in a coastal marine oxygen minimum zone

NASA Astrophysics Data System (ADS)

Padilla, C. C.; Bristow, L. A.; Sarode, N. D.; Garcia-Robledo, E.; Girguis, P. R.; Thamdrup, B.; Stewart, F. J.

2016-02-01

The pelagic ocean is a sink for the potent greenhouse gas methane, with methane consumption regulated primarily by aerobic methane-oxidizing bacteria (MOB). Marine oxygen minimum zones (OMZs) contain the largest pool of pelagic methane in the oceans but remain largely unexplored for their potential to harbor MOB communities and contribute to methane cycling. Here, we present meta-omic and geochemical evidence that aerobic MOB are present and active in a coastal OMZ, in Golfo Dulce, Costa Rica. Oxygen concentrations were < 50 nM below 85 m, and sulfide accumulated below 140 m, with methane concentrations ranging from trace levels above the oxycline to 78 nM at 180 m. The upper OMZ (90 m) was characterized by an abundant MOB and methylotroph community representing diverse lineages of the Methylophilaceae, Methylophaga, and Methylococcales. Of these, Type I methanotrophs of the Order Methylococcales dominated , representing >5% of total 16S rRNA genes and >19% of 16S rRNA transcripts. This peak in ribosomal abundance and activity was affiliated with methane oxidation rates of 2.6 ± 0.7 nM d-1, measured in seawater incubations with estimated O2 concentrations of 50 nM. Rates fell to zero with the addition of acetylene, an inhibitor of aerobic methanotrophy. In contrast, methane oxidation was below detection at lower depths in the OMZ (100 m and 120 m). Metatranscriptome sequencing indicated a peak at 90 m in the expression of pathways essential to Methylococcales, including aerobic methanotrophy and the RuMP pathway of carbon assimilation, as well as the serine pathway of Type II methanotrophs. Preliminary analysis of single-cell genomes suggests distinct adaptations by Methylococcales from the Golfo Dulce, helping explain the persistence of putative aerobic methanotrophs under very low oxygen in this OMZ. Taken together, these data suggest the boundary layers of OMZs, despite extreme oxygen depletion, are a niche for aerobic MOBs and therefore potentially important zones of pelagic methane loss.

A novel comparative effectiveness study of Tai Chi versus aerobic exercise for fibromyalgia: study protocol for a randomized controlled trial.

PubMed

Wang, Chenchen; McAlindon, Timothy; Fielding, Roger A; Harvey, William F; Driban, Jeffrey B; Price, Lori Lyn; Kalish, Robert; Schmid, Anna; Scott, Tammy M; Schmid, Christopher H

2015-01-30

Fibromyalgia is a chronic musculoskeletal pain syndrome that causes substantial physical and psychological impairment and costs the US healthcare system over $25 billion annually. Current pharmacological therapies may cause serious adverse effects, are expensive, and fail to effectively improve pain and function. Finding new and effective non-pharmacological treatments for fibromyalgia patients is urgently needed. We are currently conducting the first comparative effectiveness randomized trial of Tai Chi versus aerobic exercise (a recommended component of the current standard of care) in a large fibromyalgia population. This article describes the design and conduct of this trial. A single-center, 52-week, randomized controlled trial of Tai Chi versus aerobic exercise is being conducted at an urban tertiary medical center in Boston, Massachusetts. We plan to recruit 216 patients with fibromyalgia. The study population consists of adults ≥21 years of age with fibromyalgia who meet American College of Rheumatology 1990 and 2010 diagnostic criteria. Participants are randomized to one of four Tai Chi intervention groups: 12 or 24 weeks of supervised Tai Chi held once or twice per week, or a supervised aerobic exercise control held twice per week for 24 weeks. The primary outcome is the change in Revised Fibromyalgia Impact Questionnaire total score from baseline to 24 weeks. Secondary outcomes include measures of widespread pain, symptom severity, functional performance, balance, muscle strength and power, psychological functioning, sleep quality, self-efficacy, durability effects, and health-related quality of life at 12, 24, and 52 week follow-up. This study is the first comparative effectiveness randomized trial of Tai Chi versus aerobic exercise in a large fibromyalgia population with long-term follow up. We present here a robust and well-designed trial to determine the optimal frequency and duration of a supervised Tai Chi intervention with regard to short- and long-term effectiveness. The trial also explores multiple outcomes to elucidate the potential mechanisms of Tai Chi and aerobic exercise and the generalizability of these interventions across instructors. Results of this study are expected to have important public health implications for patients with a major disabling disease that incurs substantial health burdens and economic costs. ClinicalTrials.gov identifier: NCT01420640 , registered 18 August 2011.

Study of the diversity of microbial communities in a sequencing batch reactor oxic-settling-anaerobic process and its modified process.

PubMed

Sun, Lianpeng; Chen, Jianfan; Wei, Xiange; Guo, Wuzhen; Lin, Meishan; Yu, Xiaoyu

2016-05-01

To further reveal the mechanism of sludge reduction in the oxic-settling-anaerobic (OSA) process, the polymerase chain reaction - denaturing gradient gel electrophoresis protocol was used to study the possible difference in the microbial communities between a sequencing batch reactor (SBR)-OSA process and its modified process, by analyzing the change in the diversity of the microbial communities in each reactor of both systems. The results indicated that the structure of the microbial communities in aerobic reactors of the 2 processes was very different, but the predominant microbial populations in anaerobic reactors were similar. The predominant microbial population in the aerobic reactor of the SBR-OSA belonged to Burkholderia cepacia, class Betaproteobacteria, while those of the modified process belonged to the classes Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. These 3 types of microbes had a cryptic growth characteristic, which was the main cause of a greater sludge reduction efficiency achieved by the modified process.

Physical activity and the elderly.

PubMed

Hollmann, Wildor; Strüder, Heiko K; Tagarakis, Christos V M; King, Gerard

2007-12-01

Functional ageing processes are characterized by a loss of performance capabilities regarding coordination, flexibility, strength, speed, and endurance. The effects of ageing processes on the cardiovascular system and skeletal muscle are the foci of attention. After age 30, the maximum aerobic dynamic performance capacity decreases by an average of 8% per decade. The causes are mainly a reduction in the maximum cardiac output and decreases in capillarization and in the skeletal muscle mass. An improvement in the maximum oxygen uptake by 18% and in the aerobic-anaerobic threshold by 22% was achieved in untrained men aged 55-70 years, in a 12-week-long bicycle ergometer-training programme. The strength of the skeletal muscle decreases particularly after 50-60 years of age. The main cause is the reduction in the number of motor units and muscle fibres. Further, modifications of the endothelial function and the development of sarcopenia are of particular importance in ageing processes. General aerobic dynamic training can improve the endothelial function in old age and thus help prevent cardiovascular diseases. Strength training is most appropriate for the prevention of sarcopenia. Imaging techniques over the last 20 years have provided new findings on the influence and the significance of physical activity on the brain. We call this new interdisciplinary area 'Exercise Neuroscience'. Demands on coordination and aerobic dynamic endurance are suitable in counteracting age-related neuronal cellular loss, synapsis hypotrophy, and in improving neurogenesis and capillarization. Adjusted physical activity is thus capable of counteracting age-related changes and performance loss not only in the cardiovascular system but also in the brain.

Bacteriological aspects implicated in abdominal surgical emergencies.

PubMed

Israil, A M; Delcaru, C; Palade, R S; Chifiriuc, C; Iordache, C; Vasile, D; Grigoriu, M; Voiculescu, D

2010-01-01

The purpose of the present study was to establish the microbial etiology of abdominal surgical emergencies as well as the relationship between the bacterial etiology and the virulence factors produced by the respective isolated strains. 110 bacterial strains were isolated from 100 randomized clinical cases, operated during 2009-2010 in the First Surgical Clinic of the University Hospital of Bucharest. The clinical cases (sex ratio 52 M/48F aged between 22-85 years old) were classified into three risk groups, as related to their severity. The isolated strains were characterized by cultural, microscopic and biochemical methods. After identification, the bacterial strains were investigated for their virulence potential (adherence to abiotic surface and production of soluble virulence factors). The specimens were collected from different clinical pathologies: diffuse acute peritonitis, biliary duct infections, severe acute pancreatitis followed by septic processes etc. The 110 bacterial (72 aerobic and 38 anaerobic) strains were isolated only in 70 out of 100 cases. Out of these 70 cases, in 45 already submitted to pre-operatory empiric broad spectrum antibiotic therapy, there were isolated 74 strains, whereas in 25 cases without any treatment, there were isolated 36 strains. The etiology was either mono-specific or multi-specific (aerobic-anaerobic associations, especially in old persons). Out of the 30 negative culture cases, 16 were already submitted to pre-operatory parenteral empiric antibiotic therapy at the moment of specimen collection. The aerobic etiology was dominated by Enterobacteriaceae. The most frequent anaerobic species belonged to Clostridium, Peptococcus and Bacteroides genera. It is to be mentioned that the isolation of Bifidobacterium and Veillonella spp. in 11 (10%) severe cases of the studied abdominal surgical emergencies is pleading for the fact that in certain conditions, bacteria belonging usually to commensal gut flora can turn to pathogenic becoming responsive for life-threatening cases. All aerobic and anaerobic strains exhibited some of the following virulence factors: mucinase, esculinase, pore-forming toxins (lecithinase), proteolytic enzymes, adherence ability (slime factor). The presence of these virulence factors (VF) could explain the severity of the clinical aspects. The bacterial etiology of the abdominal surgical emergencies exhibited a very large spectrum, the highest number of strains being of endogenous origin (Enterobacteriaceae and anaerobic strains). It was demonstrated that the isolated strains produced (cell associated and soluble) VF proving in this way their role as important virulence sources in the hospital environment and explaining the large diversity and severity of the clinical abdominal pathology. The results of the present study are also pleading for periodical readjustments of the pre-operatory empiric antibiotic therapy.

Rehabilitation for improved cognition in patients with stress-related exhaustion disorder: RECO - a randomized clinical trial.

PubMed

Malmberg Gavelin, Hanna; Eskilsson, Therese; Boraxbekk, Carl-Johan; Josefsson, Maria; Stigsdotter Neely, Anna; Slunga Järvholm, Lisbeth

2018-04-25

Stress-related exhaustion has been associated with selective and enduring cognitive impairments. However, little is known about how to address cognitive deficits in stress rehabilitation and how this influences stress recovery over time. The aim of this open-label, parallel randomized controlled trial (ClinicalTrials.gov: NCT03073772) was to investigate the long-term effects of 12 weeks cognitive or aerobic training on cognitive function, psychological health, and work ability for patients diagnosed with exhaustion disorder (ED). One-hundred-and-thirty-two patients (111 women) participating in multimodal stress rehabilitation were randomized to receive additional cognitive training (n = 44), additional aerobic training (n = 47), or no additional training (n = 41). Treatment effects were assessed before, immediately after and one-year post intervention. The primary outcome was global cognitive function. Secondary outcomes included domain-specific cognition, self-reported burnout, depression, anxiety, fatigue and work ability, aerobic capacity, and sick-leave levels. Intention-to-treat analysis revealed a small but lasting improvement in global cognitive functioning for the cognitive training group, paralleled by a large improvement on a trained updating task. The aerobic training group showed improvements in aerobic capacity and episodic memory immediately after training, but no long-term benefits. General improvements in psychological health and work ability were observed, with no difference between interventional groups. Our findings suggest that cognitive training may be a viable method to address cognitive impairments for patients with ED, whereas the effects of aerobic exercise on cognition may be more limited when performed during a restricted time period. The implications for clinical practice in supporting patients with ED to adhere to treatment are discussed.

A Na+-coupled C4-dicarboxylate transporter (Asuc_0304) and aerobic growth of Actinobacillus succinogenes on C4-dicarboxylates.

PubMed

Rhie, Mi Na; Yoon, Hyo Eun; Oh, Hye Yun; Zedler, Sandra; Unden, Gottfried; Kim, Ok Bin

2014-07-01

Actinobacillus succinogenes, which is known to produce large amounts of succinate during fermentation of hexoses, was able to grow on C4-dicarboxylates such as fumarate under aerobic and anaerobic conditions. Anaerobic growth on fumarate was stimulated by glycerol and the major product was succinate, indicating the involvement of fumarate respiration similar to succinate production from glucose. The aerobic growth on C4-dicarboxylates and the transport proteins involved were studied. Fumarate was oxidized to acetate. The genome of A. succinogenes encodes six proteins with similarity to secondary C4-dicarboxylate transporters, including transporters of the Dcu (C4-dicarboxylate uptake), DcuC (C4-dicarboxylate uptake C), DASS (divalent anion : sodium symporter) and TDT (tellurite resistance dicarboxylate transporter) family. From the cloned genes, Asuc_0304 of the DASS family protein was able to restore aerobic growth on C4-dicarboxylates in a C4-dicarboxylate-transport-negative Escherichia coli strain. The strain regained succinate or fumarate uptake, which was dependent on the electrochemical proton potential and the presence of Na(+). The transport had an optimum pH ~7, indicating transport of the dianionic C4-dicarboxylates. Transport competition experiments suggested substrate specificity for fumarate and succinate. The transport characteristics for C4-dicarboxylate uptake by cells of aerobically grown A. succinogenes were similar to those of Asuc_0304 expressed in E. coli, suggesting that Asuc_0304 has an important role in aerobic fumarate uptake in A. succinogenes. Asuc_0304 has sequence similarity to bacterial Na(+)-dicarboxylate cotransporters and contains the carboxylate-binding signature. Asuc_0304 was named SdcA (sodium-coupled C4-dicarboxylate transporter from A. succinogenes). © 2014 The Authors.

SITE TECHNOLOGY CAPSULE: ZENOGEM™ WASTEWATER TREATMENT PROCESS

EPA Science Inventory

Zenon Environmental System's ZenoGem™ Wastewater Treatment Process treats aqueous media contaminated with volatile/semi-volatile organic compounds. This technology combines aerobic biological treatment to remove biodegradable organic compounds with ultrafiltration to separate res...

Bioregenerative technologies for waste processing and resource recovery in advanced space life support system

NASA Technical Reports Server (NTRS)

Chamberland, Dennis

1991-01-01

The Controlled Ecological Life Support System (CELSS) for producing oxygen, water, and food in space will require an interactive facility to process and return wastes as resources to the system. This paper examines the bioregenerative techologies for waste processing and resource recovery considered for a CELSS Resource Recovery system. The components of this system consist of a series of biological reactors to treat the liquid and solid material fractions, in which the aerobic and anaerobic reactors are combined in a block called the Combined Reactor Equipment (CORE) block. The CORE block accepts the human wastes, kitchen wastes, inedible refractory plant materials, grey waters from the CELLS system, and aquaculture solids and processes these materials in either aerobic or anaerobic reactors depending on the desired product and the rates required by the integrated system.

Oxygen Transfer in Moving Bed Biofilm Reactor and Integrated Fixed Film Activated Sludge Processes.

PubMed

2017-11-17

A demonstrated approach to design the, so-called, medium-bubble air diffusion network for oxygen transfer into the aerobic zone(s) of moving bed biofilm reactor (MBBR) and integrated fixed-film activated sludge (IFAS) processes is described in this paper. Operational full-scale biological water resource recovery systems treating municipal sewerage demonstrate that medium-bubble air diffusion networks designed using the method presented here provide reliable service. Further improvement is possible, however, as knowledge gaps prevent more rational process designs. Filling such knowledge gaps can potentially result in higher performing and more economical systems. Small-scale system testing demonstrates significant enhancement of oxygen transfer capacity due to the presence of media, but quantification of such effects in full-scale systems is lacking, and is needed. Establishment of the relationship between diffuser submergence, aeration rate, and biofilm carrier fill fraction will enhance MBBR and IFAS aerobic process design, cost, and performance. Limited testing of full-scale systems is available to allow computation of alpha valuess. As with clean water testing of full-scale systems, further full-scale testing under actual operating conditions is required to more fully quantify MBBR and IFAS system oxygen transfer performance under a wide range of operating conditions. Control of MBBR and IFAS aerobic zone oxygen transfer systems can be optimized by recognizing that varying residual dissolved oxygen (DO) concentrations are needed, depending on operating conditions. For example, the DO concentration in the aerobic zone of nitrifying IFAS processes can be lowered during warm weather conditions when greater suspended growth nitrification can occur, resulting in the need for reduced nitrification by the biofilm compartment. Further application of oxygen transfer control approaches used in activated sludge systems to MBBR and IFAS systems, such as ammonia-based oxygen transfer system control, has been demonstrated to further improve MBBR and IFAS system energy-efficiency.

In situ bioremediation of petroleum hydrocarbons and chlorinated hydrocarbons: Three case studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bost, R.C.; Perry, R.G.; Barber, T.

1997-06-01

In situ biodegradation of organic contaminants is one of the most cost-effective means of site remediation. This method has proven successful in soils, ground water, and slurries. Bacteria capable of degrading organic contaminants within an aquifer include many species from a wide spectrum of genera, e.g. Pseudomonas, Corynebacterium, Bacillus, etc. In most cases, a mixture of bacterial strains is required to completely oxidize a complex organic contaminant. Each strain of an organism may target a specific compound, working together with other organisms to ultimately degrade each intermediate until complete degradation, also known as mineralization, occurs. One or more of themore » following mechanisms are utilized by bacteria for organic chemical degradation: (1) aerobic, (2) anaerobic, and (3) co-metabolic. During aerobic oxidation of organic chemicals, bacteria utilize the pollutant as an electron and hydrogen source and oxygen acts as the electron and hydrogen acceptor, resulting in water. As the bacterial enzymes cleave the compound, oxidized products are produced along with energy for the reaction to proceed. This is the most rapid and widely utilized mechanism. Dehalogenation occurs under aerobic, or perhaps more often, under anoxic conditions. This process occurs in the presence of alternate electron acceptors and replaces chlorine with hydrogen. The mechanism of co-metabolism can be aerobic or anaerobic, but is more often aerobic. This process requires a separate energy source for the bacterial cell because the pollutant is not utilized as an energy source. The role of bioremediation in site remediation is demonstrated below by three case studies: (1) a refinery, (2) a municipal landfill and (3) a pesticide formulation plant.« less

Aerobic physical exercise as a possible treatment for neurocognitive dysfunction in bipolar disorder.

PubMed

Kucyi, Aaron; Alsuwaidan, Mohammad T; Liauw, Samantha S; McIntyre, Roger S

2010-11-01

Neurocognitive dysfunction associated with bipolar disorder (BD) is pervasive, persistent across illness phases, and is demonstrated to predispose and portend psychosocial impairment. Moreover, no approved therapies for various phases of BD have been shown to reliably improve any dimension of neurocognitive performance. In this article, we emphasize that aerobic physical exercise is a viable neurocognitive-enhancing adjunctive treatment for patients with BD. The overarching aim of this review is to emphasize that aerobic physical exercise is a viable neurocognitive-enhancing adjunctive treatment for patients with BD. We conducted PubMed and Google Scholar searches of all English-language articles published between January 1966 and February 2010 using the search terms bipolar disorder, major depressive disorder, depression, exercise, and physical activity cross-referenced with each other and the following terms: cognition, executive function, learning, memory, attention, emotion, and behavior. Articles selected for review were based on adequacy of sample size, use of standardized experimental procedures, validated assessment measures, and overall quality. Available studies have documented an array of persisting neurocognitive deficits across disparate bipolar populations. Abnormalities in verbal working memory are highly replicated; deficits in executive function, learning, attention, and processing speed are also a consistent abnormality. The effect sizes of neurocognitive deficits in BD are intermediate between those reported in schizophrenia and major depressive disorder. Several original reports and reviews have documented the neurocognitive-enhancing effects of aerobic exercise in the general population as well as across diverse medical populations and ages. Proposed mechanisms involve nonexclusive effects on neurogenesis, neurotrophism, immunoinflammatory systems, insulin sensitivity, and neurotransmitter systems. Each of these effector systems are implicated in both normal and abnormal neurocognitive processes in BD. Available evidence provides a rationale for empirically evaluating the neurocognitive benefits of aerobic exercise in BD.

Implementation of compulsory hazard analysis critical control point system and its effect on concentrations of carcass and environmental surface bacterial indicators in United Kingdom red meat slaughterhouses.

PubMed

Hutchison, Michael L; Thomas, D John I; Small, Alison H; Buncic, Sava; Howell, Mary

2007-07-01

Statutory microbiological test results were collected from British meat plants over a 4-year period from June 2002 to May 2006. A total of 49,074 carcass test results from 19,409 cattle, 14,706 sheep, and 14,959 pig swabs and 95,179 environmental test results from surface swabs were obtained. These test results were donated by 94 slaughterhouses, which process about two thirds of the British national annual throughput of cattle, sheep, and pig carcasses. The data were collectively analyzed to determine any historical trends for numbers of total aerobes and Enterobacteriaceae. Significant reductions were observed in the numbers of indicator organisms on carcasses for all three species between 2002 and 2006. Reductions were also observed for numbers of aerobes on environmental and food contact surfaces. There were seasonal differences in bacterial numbers isolated from carcasses. Cattle and sheep carcasses had significantly higher numbers of total aerobes and Enterobacteriaceae in late summer and early autumn, whereas numbers of total aerobes on pig carcasses were higher in winter. Bacterial numbers on environmental surfaces were not influenced by the month that the swab samples were collected. Possible reasons for the observed reductions in bacterial numbers on carcasses and surfaces and the implications for carcass testing for process control purposes are discussed.

Guano exposed: Impact of aerobic conditions on bat fecal microbiota.

PubMed

Fofanov, Viacheslav Y; Furstenau, Tara N; Sanchez, Daniel; Hepp, Crystal M; Cocking, Jill; Sobek, Colin; Pagel, Nicole; Walker, Faith; Chambers, Carol L

2018-06-01

Bats and their associated guano microbiota provide important terrestrial and subterranean ecosystem services and serve as a reservoir for a wide range of epizootic and zoonotic diseases. Unfortunately, large-scale studies of bats and their guano microbiotas are limited by the time and cost of sample collection, which requires specially trained individuals to work at night to capture bats when they are most active. Indirectly surveying bat gut microbiota through guano deposits could be a more cost-effective alternative, but it must first be established whether the postdefecation exposure to an aerobic environment has a large impact on the guano microbial community. A number of recent studies on mammalian feces have shown that the impact of aerobic exposure is highly species specific; therefore, it is difficult to predict how exposure will affect the bat guano microbiota without empirical data. In our study, we collected fresh guano samples from 24 individuals of 10 bat species that are common throughout the arid environments of the American southwest and subjected the samples to 0, 1, and 12 hr of exposure. The biodiversity decreased rapidly after the shift from an anaerobic to an aerobic environment-much faster than previously reported in mammalian species. However, the relative composition of the core guano microbiota remained stable and, using highly sensitive targeted PCR methods, we found that pathogens present in the original, non-exposed samples could still be recovered after 12 hr of exposure. These results suggest that with careful sample analysis protocols, a more efficient passive collection strategy is feasible; for example, guano could be collected on tarps placed near the roost entrance. Such passive collection methods would greatly reduce the cost of sample collection by allowing more sites or roosts to be surveyed with a fraction of trained personnel, time, and effort investments needed.

Comparative analysis of the 1-mile run test evaluation formulae: assessment of aerobic capacity in male law enforcement officers aged 20-23 years.

PubMed

Kayihan, Gürhan; Özkan, Ali; Köklü, Yusuf; Eyuboğlu, Ender; Akça, Firat; Koz, Mitat; Ersöz, Gülfem

2014-04-01

The purpose of this study was to compare values of aerobic performance in the 1-mile run test (1-MRT) using different formulae. Aerobic capacities of 351 male volunteers working for the Turkish National Police within the age range of 20-23 years were evaluated by the 1-MRT and the 20-metre shuttle run (20-MST). VO2max values were estimated by the prediction equations developed by George et al. (1993), Cureton et al. (1995) and Kline et al. (1987) for the 1-MRT and by Leger and Lambert (1982) for the 20-MST. The difference between the results of the different formulae was significant (p = 0.000). The correlation coefficient between the estimated VO2max using Cureton's equation, George's equation, Kline's equation and the 20-MST were 0.691 (p < 0.001), 0.486 (p < 0.001) and 0.608 (p < 0.001), respectively. The highest correlation coefficient was between the VO2max estimated by the 20-MST and Cureton's equation. Similarly, the highest correlation coefficient (r = -0.779) was between the 1-mile run time and the VO2max estimated by Cureton's equation. When analysing more vigorous exercise than sub-maximal exercise, we suggest that Cureton's equation be used to predict the VO2max from 1-mile run/walk performance in large numbers of healthy individuals with high VO2max. This research compares the use of 3 different formulae to estimate VO2max from 1-mile run/walk performance in male law enforcement officers aged 20-23 years for the first time and reports the most accurate formula to use when evaluating aerobic capacities of large numbers of healthy individuals.

Laboratory chalcopyrite oxidation by Acidithiobacillus ferrooxidans: Oxygen and sulfur isotope fractionation

USGS Publications Warehouse

Thurston, R.S.; Mandernack, K.W.; Shanks, Wayne C.

2010-01-01

Laboratory experiments were conducted to simulate chalcopyrite oxidation under anaerobic and aerobic conditions in the absence or presence of the bacterium Acidithiobacillus ferrooxidans. Experiments were carried out with 3 different oxygen isotope values of water (??18OH2O) so that approach to equilibrium or steady-state isotope fractionation for different starting conditions could be evaluated. The contribution of dissolved O2 and water-derived oxygen to dissolved sulfate formed by chalcopyrite oxidation was unambiguously resolved during the aerobic experiments. Aerobic oxidation of chalcopyrite showed 93 ?? 1% incorporation of water oxygen into the resulting sulfate during the biological experiments. Anaerobic experiments showed similar percentages of water oxygen incorporation into sulfate, but were more variable. The experiments also allowed determination of sulfate-water oxygen isotope fractionation, ??18OSO4-H2O, of ~ 3.8??? for the anaerobic experiments. Aerobic oxidation produced apparent ??SO4-H2O values (6.4???) higher than the anaerobic experiments, possibly due to additional incorporation of dissolved O2 into sulfate. ??34SSO4 values are ~ 4??? lower than the parent sulfide mineral during anaerobic oxidation of chalcopyrite, with no significant difference between abiotic and biological processes. For the aerobic experiments, a small depletion in ??34SSO4 of ~- 1.5 ?? 0.2??? was observed for the biological experiments. Fewer solids precipitated during oxidation under aerobic conditions than under anaerobic conditions, which may account for the observed differences in sulfur isotope fractionation under these contrasting conditions. ?? 2009 Elsevier B.V.

Temperature, metabolic power and the evolution of endothermy.

PubMed

Clarke, Andrew; Pörtner, Hans-Otto

2010-11-01

Endothermy has evolved at least twice, in the precursors to modern mammals and birds. The most widely accepted explanation for the evolution of endothermy has been selection for enhanced aerobic capacity. We review this hypothesis in the light of advances in our understanding of ATP generation by mitochondria and muscle performance. Together with the development of isotope-based techniques for the measurement of metabolic rate in free-ranging vertebrates these have confirmed the importance of aerobic scope in the evolution of endothermy: absolute aerobic scope, ATP generation by mitochondria and muscle power output are all strongly temperature-dependent, indicating that there would have been significant improvement in whole-organism locomotor ability with a warmer body. New data on mitochondrial ATP generation and proton leak suggest that the thermal physiology of mitochondria may differ between organisms of contrasting ecology and thermal flexibility. Together with recent biophysical modelling, this strengthens the long-held view that endothermy originated in smaller, active eurythermal ectotherms living in a cool but variable thermal environment. We propose that rather than being a secondary consequence of the evolution of an enhanced aerobic scope, a warmer body was the means by which that enhanced aerobic scope was achieved. This modified hypothesis requires that the rise in metabolic rate and the insulation necessary to retain metabolic heat arose early in the lineages leading to birds and mammals. Large dinosaurs were warm, but were not endotherms, and the metabolic status of pterosaurs remains unresolved. © 2010 The Authors. Biological Reviews © 2010 Cambridge Philosophical Society.

Stable Isotope-Assisted Metabolic Profiling Reveals Growth Mode Dependent Differential Metabolism and Multiple Catabolic Pathways of l-Phenylalanine in Rubrivivax benzoatilyticus JA2.

PubMed

Mekala, Lakshmi Prasuna; Mohammed, Mujahid; Chintalapati, Sasikala; Chintalapati, Venkata Ramana

2018-01-05

Anoxygenic phototrophic bacteria are metabolically versatile and survive under different growth modes using diverse organic compounds, yet their metabolic diversity is largely unexplored. In the present study, we employed stable-isotope-assisted metabolic profiling to unravel the l-phenylalanine catabolism in Rubrivivax benzoatilyticus JA2 under varying growth modes. Strain JA2 grows under anaerobic and aerobic conditions by utilizing l-phenylalanine as a nitrogen source. Furthermore, ring-labeled 13 C 6 -phenylalanine feeding followed by liquid chromatography-mass spectrometry exometabolite profiling revealed 60 labeled metabolic features (M + 6, M + 12, and M + 18) derived solely from l-phenylalanine, of which 11 were identified, 7 putatively identified, and 42 unidentified under anaerobic and aerobic conditions. However, labeled metabolites were significantly higher in aerobic compared to anaerobic conditions. Furthermore, detected metabolites and enzyme activities indicated multiple l-phenylalanine catabolic routes mainly Ehrlich, homogentisate-dependent melanin, benzenoid, and unidentified pathways operating under anaerobic and aerobic conditions in strain JA2. Interestingly, the study indicated l-phenylalanine-dependent and independent benzenoid biosynthesis in strain JA2 and a differential flux of l-phenylalanine to Ehrlich and benzenoid pathways under anaerobic and aerobic conditions. Additionally, unidentified labeled metabolites strongly suggest the presence of unknown phenylalanine catabolic routes in strain JA2. Overall, the study uncovered the l-phenylalanine catabolic diversity in strain JA2 and demonstrated the potential of stable isotope-assisted metabolomics in unraveling the hidden metabolic repertoire.

Mathematical Simulation of the Process of Aerobic Treatment of Wastewater under Conditions of Diffusion and Mass Transfer Perturbations

NASA Astrophysics Data System (ADS)

Bomba, A. Ya.; Safonik, A. P.

2018-05-01

A mathematical model of the process of aerobic treatment of wastewater has been refined. It takes into account the interaction of bacteria, as well as of organic and biologically nonoxidizing substances under conditions of diffusion and mass transfer perturbations. An algorithm of the solution of the corresponding nonlinear perturbed problem of convection-diffusion-mass transfer type has been constructed, with a computer experiment carried out based on it. The influence of the concentration of oxygen and of activated sludge on the quality of treatment is shown. Within the framework of the model suggested, a possibility of automated control of the process of deposition of impurities in a biological filter depending on the initial parameters of the water medium is suggested.

Mathematical Simulation of the Process of Aerobic Treatment of Wastewater under Conditions of Diffusion and Mass Transfer Perturbations

NASA Astrophysics Data System (ADS)

Bomba, A. Ya.; Safonik, A. P.

2018-03-01

A mathematical model of the process of aerobic treatment of wastewater has been refined. It takes into account the interaction of bacteria, as well as of organic and biologically nonoxidizing substances under conditions of diffusion and mass transfer perturbations. An algorithm of the solution of the corresponding nonlinear perturbed problem of convection-diffusion-mass transfer type has been constructed, with a computer experiment carried out based on it. The influence of the concentration of oxygen and of activated sludge on the quality of treatment is shown. Within the framework of the model suggested, a possibility of automated control of the process of deposition of impurities in a biological filter depending on the initial parameters of the water medium is suggested.

High cell density media for Escherichia coli are generally designed for aerobic cultivations – consequences for large-scale bioprocesses and shake flask cultures

PubMed Central

Soini, Jaakko; Ukkonen, Kaisa; Neubauer, Peter

2008-01-01

Background For the cultivation of Escherichia coli in bioreactors trace element solutions are generally designed for optimal growth under aerobic conditions. They do normally not contain selenium and nickel. Molybdenum is only contained in few of them. These elements are part of the formate hydrogen lyase (FHL) complex which is induced under anaerobic conditions. As it is generally known that oxygen limitation appears in shake flask cultures and locally in large-scale bioreactors, function of the FHL complex may influence the process behaviour. Formate has been described to accumulate in large-scale cultures and may have toxic effects on E. coli. Although the anaerobic metabolism of E. coli is well studied, reference data which estimate the impact of the FHL complex on bioprocesses of E. coli with oxygen limitation have so far not been published, but are important for a better process understanding. Results Two sets of fed-batch cultures with conditions triggering oxygen limitation and formate accumulation were performed. Permanent oxygen limitation which is typical for shake flask cultures was caused in a bioreactor by reduction of the agitation rate. Transient oxygen limitation, which has been described to eventually occur in the feed-zone of large-scale bioreactors, was mimicked in a two-compartment scale-down bioreactor consisting of a stirred tank reactor and a plug flow reactor (PFR) with continuous glucose feeding into the PFR. In both models formate accumulated up to about 20 mM in the culture medium without addition of selenium, molybdenum and nickel. By addition of these trace elements the formate accumulation decreased below the level observed in well-mixed laboratory-scale cultures. Interestingly, addition of the extra trace elements caused accumulation of large amounts of lactate and reduced biomass yield in the simulator with permanent oxygen limitation, but not in the scale-down two-compartment bioreactor. Conclusion The accumulation of formate in oxygen limited cultivations of E. coli can be fully prevented by addition of the trace elements selenium, nickel and molybdenum, necessary for the function of FHL complex. For large-scale cultivations, if glucose gradients are likely, the results from the two-compartment scale-down bioreactor indicate that the addition of the extra trace elements is beneficial. No negative effects on the biomass yield or on any other bioprocess parameters could be observed in cultures with the extra trace elements if the cells were repeatedly exposed to transient oxygen limitation. PMID:18687130

A Constitutive Expression System for Cellulase Secretion in Escherichia coli and Its Use in Bioethanol Production

PubMed Central

Munjal, Neha; Jawed, Kamran; Wajid, Saima; Yazdani, Syed Shams

2015-01-01

The production of biofuels from lignocellulosic biomass appears to be attractive and viable due to the abundance and availability of this biomass. The hydrolysis of this biomass, however, is challenging because of the complex lignocellulosic structure. The ability to produce hydrolytic cellulase enzymes in a cost-effective manner will certainly accelerate the process of making lignocellulosic ethanol production a commercial reality. These cellulases may need to be produced aerobically to generate large amounts of protein in a short time or anaerobically to produce biofuels from cellulose via consolidated bioprocessing. Therefore, it is important to identify a promoter that can constitutively drive the expression of cellulases under both aerobic and anaerobic conditions without the need for an inducer. Using lacZ as reporter gene, we analyzed the strength of the promoters of four genes, namely lacZ, gapA, ldhA and pflB, and found that the gapA promoter yielded the maximum expression of the β-galactosidase enzyme under both aerobic and anaerobic conditions. We further cloned the genes for two cellulolytic enzymes, β-1,4-endoglucanase and β-1,4-glucosidase, under the control of the gapA promoter, and we expressed these genes in Escherichia coli, which secreted the products into the extracellular medium. An ethanologenic E. colistrain transformed with the secretory β-glucosidase gene construct fermented cellobiose in both defined and complex medium. This recombinant strain also fermented wheat straw hydrolysate containing glucose, xylose and cellobiose into ethanol with an 85% efficiency of biotransformation. An ethanologenic strain that constitutively secretes a cellulolytic enzyme is a promising platform for producing lignocellulosic ethanol. PMID:25768292

Acute aerobic exercise increases cortical activity during working memory: a functional MRI study in female college students.

PubMed

Li, Lin; Men, Wei-Wei; Chang, Yu-Kai; Fan, Ming-Xia; Ji, Liu; Wei, Gao-Xia

2014-01-01

There is increasing evidence that acute aerobic exercise is associated with improved cognitive function. However, neural correlates of its cognitive plasticity remain largely unknown. The present study examined the effect of a session of acute aerobic exercise on working memory task-evoked brain activity as well as task performance. A within-subjects design with a counterbalanced order was employed. Fifteen young female participants (M = 19.56, SD = 0.81) were scanned using functional magnetic resonance imaging while performing a working memory task, the N-back task, both following an acute exercise session with 20 minutes of moderate intensity and a control rest session. Although an acute session of exercise did not improve behavioral performance, we observed that it had a significant impact on brain activity during the 2-back condition of the N-back task. Specifically, acute exercise induced increased brain activation in the right middle prefrontal gyrus, the right lingual gyrus, and the left fusiform gyrus as well as deactivations in the anterior cingulate cortexes, the left inferior frontal gyrus, and the right paracentral lobule. Despite the lack of an effect on behavioral measures, significant changes after acute exercise with activation of the prefrontal and occipital cortexes and deactivation of the anterior cingulate cortexes and left frontal hemisphere reflect the improvement of executive control processes, indicating that acute exercise could benefit working memory at a macro-neural level. In addition to its effects on reversing recent obesity and disease trends, our results provide substantial evidence highlighting the importance of promoting physical activity across the lifespan to prevent or reverse cognitive and neural decline.

Loss of Brain Aerobic Glycolysis in Normal Human Aging.

PubMed

Goyal, Manu S; Vlassenko, Andrei G; Blazey, Tyler M; Su, Yi; Couture, Lars E; Durbin, Tony J; Bateman, Randall J; Benzinger, Tammie L-S; Morris, John C; Raichle, Marcus E

2017-08-01

The normal aging human brain experiences global decreases in metabolism, but whether this affects the topography of brain metabolism is unknown. Here we describe PET-based measurements of brain glucose uptake, oxygen utilization, and blood flow in cognitively normal adults from 20 to 82 years of age. Age-related decreases in brain glucose uptake exceed that of oxygen use, resulting in loss of brain aerobic glycolysis (AG). Whereas the topographies of total brain glucose uptake, oxygen utilization, and blood flow remain largely stable with age, brain AG topography changes significantly. Brain regions with high AG in young adults show the greatest change, as do regions with prolonged developmental transcriptional features (i.e., neoteny). The normal aging human brain thus undergoes characteristic metabolic changes, largely driven by global loss and topographic changes in brain AG. Copyright © 2017 Elsevier Inc. All rights reserved.

Biological treatment of thin-film transistor liquid crystal display (TFT-LCD) wastewater using aerobic and anoxic/oxic sequencing batch reactors.

PubMed

Lei, Chin-Nan; Whang, Liang-Ming; Chen, Po-Chun

2010-09-01

The amount of pollutants produced during manufacturing processes of thin-film transistor liquid crystal display (TFT-LCD) substantially increases due to an increasing production of the opto-electronic industry in Taiwan. This study presents the treatment performance of one aerobic and one anoxic/oxic (A/O) sequencing batch reactors (SBRs) treating synthetic TFT-LCD wastewater containing dimethyl sulfoxide (DMSO), monoethanolamine (MEA), and tetra-methyl ammonium hydroxide (TMAH). The long-term monitoring results for the aerobic and A/O SBRs demonstrate that stable biodegradation of DMSO, MEA, and TMAH can be achieved without any considerably adverse impacts. The ammonium released during MEA and TMAH degradation can also be completely oxidized to nitrate through nitrification in both SBRs. Batch studies on biodegradation rates for DMSO, MEA, and TMAH under anaerobic, anoxic, and aerobic conditions indicate that effective MEA degradation can be easily achieved under all three conditions examined, while efficient DMSO and TMAH degradation can be attained only under anaerobic and aerobic conditions, respectively. The potential odor problem caused by the formation of malodorous dimethyl sulfide from DMSO degradation under anaerobic conditions, however, requires insightful consideration in treating DMSO-containing wastewater. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

General Characteristics and Treatment Possibilities of
Dairy Wastewater – A Review

PubMed Central

2017-01-01

Summary The milk processing industry is one of the world’s staple industries, thus the treatment possibilities of dairy effluents have been attracting more and more attention. The purpose of the paper is to review contemporary research on dairy wastewater. The origin, categories, as well as liquid by-products and general indicators of real dairy wastewater are described. Different procedures applied for dairy wastewater management are summarised. Attention is focused on in-factory treatment technologies with the emphasis on biological processes. Aerobic and anaerobic methods with both their advantages and disadvantages are discussed in detail. Consecutive anaerobic and aerobic systems are analysed, too. Finally, future research niches are identified. PMID:28559730

High microbial loads found in minimally-processed sliced mushrooms from Italian market.

PubMed

Jiang, Haiyang; Miraglia, Dino; Ranucci, David; Donnini, Domizia; Roila, Rossana; Branciari, Raffaella; Li, Cheng

2018-03-31

There is an increased consumer interest in minimally processed vegetables that has led to the development of products, such as pre-cut sliced mushrooms. Few data are available on the hygienic condition and the presence of foodborne pathogens in such products. Therefore, the current study aimed to evaluate the safety and hygienic characteristics of both ready-to-eat and ready-to-cook, pre-cut sliced mushrooms obtained from a local Italian market. For the evaluation of the hygienic condition, the aerobic mesophilic bacteria, aerobic psychrotrophic bacteria and Escherichia coli enumerations were performed. Salmonella spp., Listeria monocytogenes and Campylobacter spp. were considered in the assessment of the foodborne pathogens. High microbial loads were detected, including counts higher than 5 log CFU/g for E. coli and 6 log CFU/g for the other bacteria counts considered, but no pathogens were found. Ready-to-eat and ready-to-cook products differed only for aerobic mesophilic counts (7.87 and 8.26 log CFU/g, respectively, P=0.003). Strategies to enhance the hygienic level of the mushrooms, particularly the ready-to-eat products, are needed.

High microbial loads found in minimally-processed sliced mushrooms from Italian market

PubMed Central

Jiang, Haiyang; Miraglia, Dino; Ranucci, David; Donnini, Domizia; Roila, Rossana; Branciari, Raffaella; Li, Cheng

2018-01-01

There is an increased consumer interest in minimally processed vegetables that has led to the development of products, such as pre-cut sliced mushrooms. Few data are available on the hygienic condition and the presence of foodborne pathogens in such products. Therefore, the current study aimed to evaluate the safety and hygienic characteristics of both ready-to-eat and ready-to-cook, pre-cut sliced mushrooms obtained from a local Italian market. For the evaluation of the hygienic condition, the aerobic mesophilic bacteria, aerobic psychrotrophic bacteria and Escherichia coli enumerations were performed. Salmonella spp., Listeria monocytogenes and Campylobacter spp. were considered in the assessment of the foodborne pathogens. High microbial loads were detected, including counts higher than 5 log CFU/g for E. coli and 6 log CFU/g for the other bacteria counts considered, but no pathogens were found. Ready-to-eat and ready-to-cook products differed only for aerobic mesophilic counts (7.87 and 8.26 log CFU/g, respectively, P=0.003). Strategies to enhance the hygienic level of the mushrooms, particularly the ready-to-eat products, are needed. PMID:29732334

Modelling for reactor-style aerobic composting based on coupling theory of mass-heat-momentum transport and Contois equation.

PubMed

He, Xueqin; Han, Lujia; Ge, Jinyi; Huang, Guangqun

2018-04-01

This study establishes an optimal mathematical modelling to rationally describe the dynamic changes and spatial distribution of temperature and oxygen concentration in the aerobic composting process using coupling mass-heat-momentum transfer based on the microbial mechanism. Two different conditional composting experiments, namely continuous aeration and intermittent aeration, were performed to verify the proposed model. The results show that the model accurately predicted the dynamic changes in temperature (case I: R 2  = 0.93, RMSE = 1.95 K; case II: R 2  = 0.86, RMSE = 4.69 K) and oxygen concentration (case I: R 2  = 0.90, RMSE = 1.26%; case II: R 2  = 0.75, RMSE = 2.93%) in the central point of compost substrates. It also systematically simulated fluctuations in oxygen concentration caused by boundary conditions and the spatial distribution of the actual temperature and oxygen concentration. The proposed model exhibits good applicability in simulating the actual working conditions of aerobic composting process. Copyright © 2018 Elsevier Ltd. All rights reserved.

Microbial degradation of chloroethenes: a review.

PubMed

Dolinová, Iva; Štrojsová, Martina; Černík, Miroslav; Němeček, Jan; Macháčková, Jiřina; Ševců, Alena

2017-05-01

Contamination by chloroethenes has a severe negative effect on both the environment and human health. This has prompted intensive remediation activity in recent years, along with research into the efficacy of natural microbial communities for degrading toxic chloroethenes into less harmful compounds. Microbial degradation of chloroethenes can take place either through anaerobic organohalide respiration, where chloroethenes serve as electron acceptors; anaerobic and aerobic metabolic degradation, where chloroethenes are used as electron donors; or anaerobic and aerobic co-metabolic degradation, with chloroethene degradation occurring as a by-product during microbial metabolism of other growth substrates, without energy or carbon benefit. Recent research has focused on optimising these natural processes to serve as effective bioremediation technologies, with particular emphasis on (a) the diversity and role of bacterial groups involved in dechlorination microbial processes, and (b) detection of bacterial enzymes and genes connected with dehalogenation activity. In this review, we summarise the different mechanisms of chloroethene bacterial degradation suitable for bioremediation and provide a list of dechlorinating bacteria. We also provide an up-to-date summary of primers available for detecting functional genes in anaerobic and aerobic bacteria degrading chloroethenes metabolically or co-metabolically.

Transcriptome and metabolome responses of Shewanella oneidensis MR-1 to methyl orange under microaerophilic and aerobic conditions.

PubMed

Cao, Xinhua; Qi, Yueling; Xu, Chen; Yang, Yuyi; Wang, Jun

2017-04-01

Shewanella oneidensis MR-1 degrades various azo dyes under microaerophilic and anaerobic conditions, but this process is inhibited under aerobic conditions. The mechanisms underlying azo dye biodegradation and inhibition remain unknown. Therefore, we investigated metabolic and transcriptional changes in strain MR-1, which was cultured under different conditions, to elucidate these mechanisms. At the transcriptional level, genes involved in certain metabolic processes, particularly the tricarboxylic acid (TCA) cycle, amino acid biodegradation, and the electron transfer system, were significantly altered (M ≧ 2, p > 0.8 ) in the presence of methyl orange (MO). Moreover, a high concentration of dissolved oxygen heavily impacted the expression levels of genes involved in fatty acid biodegradation. Metabolome analysis revealed significant alteration (p < 0.05) in the concentrations of nine metabolites when strain MR-1 was cultured under aerobic conditions; the majority of these metabolites were closely associated with amino acid metabolism and DNA replication. Accordingly, we propose a possible pathway for MO biodegradation and discuss the most likely causes of biodegradation inhibition due to dissolved oxygen.

Aerobic Biodegradation Characteristic of Different Water-Soluble Azo Dyes.

PubMed

Sheng, Shixiong; Liu, Bo; Hou, Xiangyu; Wu, Bing; Yao, Fang; Ding, Xinchun; Huang, Lin

2017-12-26

This study investigated the biodegradation performance and characteristics of Sudan I and Acid Orange 7 (AO7) to improve the biological dye removal efficiency in wastewater and optimize the treatment process. The dyes with different water-solubility and similar molecular structure were biologically treated under aerobic condition in parallel continuous-flow mixed stirred reactors. The biophase analysis using microscopic examination suggested that the removal process of the two azo dyes is different. Removal of Sudan I was through biosorption, since it easily assembled and adsorbed on the surface of zoogloea due to its insolubility, while AO7 was biodegraded incompletely and bioconverted, the AO7 molecule was decomposed to benzene series and inorganic ions, since it could reach the interior area of zoogloea due to the low oxidation-reduction potential conditions and corresponding anaerobic microorganisms. The transformation of NH₃-N, SO₄ 2- together with the presence of tryptophan-like components confirm that AO7 can be decomposed to non-toxic products in an aerobic bioreactor. This study provides a theoretical basis for the use of biosorption or biodegradation mechanisms for the treatment of different azo dyes in wastewater.

Application of a combined process of moving-bed biofilm reactor (MBBR) and chemical coagulation for dyeing wastewater treatment.

PubMed

Shin, D H; Shin, W S; Kim, Y H; Han, Myung Ho; Choi, S J

2006-01-01

A combined process consisted of a Moving-Bed Biofilm Reactor (MBBR) and chemical coagulation was investigated for textile wastewater treatment. The pilot scale MBBR system is composed of three MBBRs (anaerobic, aerobic-1 and aerobic-2 in series), each reactor was filled with 20% (v/v) of polyurethane-activated carbon (PU-AC) carrier for biological treatment followed by chemical coagulation with FeCl2. ln the MBBR process, 85% of COD and 70% of color (influent COD = 807.5 mg/L and color = 3,400 PtCo unit) were removed using relatively low MLSS concentration and short hydraulic retention time (HRT = 44 hr). The biologically treated dyeing wastewater was subjected to chemical coagulation. After coagulation with FeCl2, 95% of COD and 97% of color were removed overall. The combined process of MBBR and chemical coagulation has promising potential for dyeing wastewater treatment.

Comparison of the 1.5 Mile Run Times at 7,200 Feet and Simulated 850 Feet in a Hyperoxic Room

DTIC Science & Technology

2011-08-02

way to estimate VO2 max, or aerobic fitness, in large groups of Air Force personnel. (R = .897) o Based on results of 115 airmen o Better...implemented to “predict” VO2 max. I n t e g r i t y - S e r v i c e - E x c e l l e n c e Distribution A. Approved for public release Background...needed. The VO2 max or aerobic fitness, the factor we are measuring with the 1.5 mile run, is not measurably altered in a non-acclimated member

Criterion Related Validity of Karate Specific Aerobic Test (KSAT)

PubMed Central

Chaabene, Helmi; Hachana, Younes; Franchini, Emerson; Tabben, Montassar; Mkaouer, Bessem; Negra, Yassine; Hammami, Mehrez; Chamari, Karim

2015-01-01

Background: Karate is one the most popular combat sports in the world. Physical fitness assessment on a regular manner is important for monitoring the effectiveness of the training program and the readiness of karatekas to compete. Objectives: The aim of this research was to examine the criterion related to validity of the karate specific aerobic test (KSAT) as an indicator of aerobic level of karate practitioners. Patients and Methods: Cardiorespiratory responses, aerobic performance level through both treadmill laboratory test and YoYo intermittent recovery test level 1 (YoYoIRTL1) as well as time to exhaustion in the KSAT test (TE’KSAT) were determined in a total of fifteen healthy international karatekas (i.e. karate practitioners) (means ± SD: age: 22.2 ± 4.3 years; height: 176.4 ± 7.5 cm; body mass: 70.3 ± 9.7 kg and body fat: 13.2 ± 6%). Results: Peak heart rate obtained from KSAT represented ~99% of maximal heart rate registered during the treadmill test showing that KSAT imposes high physiological demands. There was no significant correlation between KSAT’s TE and relative (mL/min kg) treadmill maximal oxygen uptake (r = 0.14; P = 0.69; [small]). On the other hand, there was a significant relationship between KSAT’s TE and the velocity associated with VO2max (vVO2max) (r = 0.67; P = 0.03; [large]) as well as the velocity at VO2 corresponding to the second ventilatory threshold (vVO2 VAT) (r = 0.64; P = 0.04; [large]). Moreover, significant relationship was found between TE’s KSAT and both the total distance covered and parameters of intermittent endurance measured through YoYoIRTL1. Conclusions: The KSAT has not proved to have indirect criterion related validity as no significant correlations have been found between TE’s KSAT and treadmill VO2max. Nevertheless, as correlated to other aerobic fitness variables, KSAT can be considered as an indicator of karate specific endurance. The establishment of the criterion related validity of the KSAT requires further investigation. PMID:26446345

Aerobic Toluene Degraders in the Rhizosphere of a Constructed Wetland Model Show Diurnal Polyhydroxyalkanoate Metabolism.

PubMed

Lünsmann, Vanessa; Kappelmeyer, Uwe; Taubert, Anja; Nijenhuis, Ivonne; von Bergen, Martin; Heipieper, Hermann J; Müller, Jochen A; Jehmlich, Nico

2016-07-15

Constructed wetlands (CWs) are successfully applied for the treatment of waters contaminated with aromatic compounds. In these systems, plants provide oxygen and root exudates to the rhizosphere and thereby stimulate microbial degradation processes. Root exudation of oxygen and organic compounds depends on photosynthetic activity and thus may show day-night fluctuations. While diurnal changes in CW effluent composition have been observed, information on respective fluctuations of bacterial activity are scarce. We investigated microbial processes in a CW model system treating toluene-contaminated water which showed diurnal oscillations of oxygen concentrations using metaproteomics. Quantitative real-time PCR was applied to assess diurnal expression patterns of genes involved in aerobic and anaerobic toluene degradation. We observed stable aerobic toluene turnover by Burkholderiales during the day and night. Polyhydroxyalkanoate synthesis was upregulated in these bacteria during the day, suggesting that they additionally feed on organic root exudates while reutilizing the stored carbon compounds during the night via the glyoxylate cycle. Although mRNA copies encoding the anaerobic enzyme benzylsuccinate synthase (bssA) were relatively abundant and increased slightly at night, the corresponding protein could not be detected in the CW model system. Our study provides insights into diurnal patterns of microbial processes occurring in the rhizosphere of an aquatic ecosystem. Constructed wetlands are a well-established and cost-efficient option for the bioremediation of contaminated waters. While it is commonly accepted knowledge that the function of CWs is determined by the interplay of plants and microorganisms, the detailed molecular processes are considered a black box. Here, we used a well-characterized CW model system treating toluene-contaminated water to investigate the microbial processes influenced by diurnal plant root exudation. Our results indicated stable aerobic toluene degradation by members of the Burkholderiales during the day and night. Polyhydroxyalkanoate synthesis in these bacteria was higher during the day, suggesting that they additionally fed on organic root exudates and reutilized the stored carbon compounds during the night. Our study illuminates microbial processes occurring in the rhizosphere of an aquatic ecosystem. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Aerobic Toluene Degraders in the Rhizosphere of a Constructed Wetland Model Show Diurnal Polyhydroxyalkanoate Metabolism

PubMed Central

Lünsmann, Vanessa; Kappelmeyer, Uwe; Taubert, Anja; Nijenhuis, Ivonne; von Bergen, Martin; Müller, Jochen A.; Jehmlich, Nico

2016-01-01

ABSTRACT Constructed wetlands (CWs) are successfully applied for the treatment of waters contaminated with aromatic compounds. In these systems, plants provide oxygen and root exudates to the rhizosphere and thereby stimulate microbial degradation processes. Root exudation of oxygen and organic compounds depends on photosynthetic activity and thus may show day-night fluctuations. While diurnal changes in CW effluent composition have been observed, information on respective fluctuations of bacterial activity are scarce. We investigated microbial processes in a CW model system treating toluene-contaminated water which showed diurnal oscillations of oxygen concentrations using metaproteomics. Quantitative real-time PCR was applied to assess diurnal expression patterns of genes involved in aerobic and anaerobic toluene degradation. We observed stable aerobic toluene turnover by Burkholderiales during the day and night. Polyhydroxyalkanoate synthesis was upregulated in these bacteria during the day, suggesting that they additionally feed on organic root exudates while reutilizing the stored carbon compounds during the night via the glyoxylate cycle. Although mRNA copies encoding the anaerobic enzyme benzylsuccinate synthase (bssA) were relatively abundant and increased slightly at night, the corresponding protein could not be detected in the CW model system. Our study provides insights into diurnal patterns of microbial processes occurring in the rhizosphere of an aquatic ecosystem. IMPORTANCE Constructed wetlands are a well-established and cost-efficient option for the bioremediation of contaminated waters. While it is commonly accepted knowledge that the function of CWs is determined by the interplay of plants and microorganisms, the detailed molecular processes are considered a black box. Here, we used a well-characterized CW model system treating toluene-contaminated water to investigate the microbial processes influenced by diurnal plant root exudation. Our results indicated stable aerobic toluene degradation by members of the Burkholderiales during the day and night. Polyhydroxyalkanoate synthesis in these bacteria was higher during the day, suggesting that they additionally fed on organic root exudates and reutilized the stored carbon compounds during the night. Our study illuminates microbial processes occurring in the rhizosphere of an aquatic ecosystem. PMID:27129963

Reprogramming of Escherichia coli K-12 Metabolism during the Initial Phase of Transition from an Anaerobic to a Micro-Aerobic Environment

PubMed Central

Trotter, Eleanor W.; Rolfe, Matthew D.; Hounslow, Andrea M.; Craven, C. Jeremy; Williamson, Michael P.; Sanguinetti, Guido; Poole, Robert K.; Green, Jeffrey

2011-01-01

Background Many bacteria undergo transitions between environments with differing O2 availabilities as part of their natural lifestyles and during biotechnological processes. However, the dynamics of adaptation when bacteria experience changes in O2 availability are understudied. The model bacterium and facultative anaerobe Escherichia coli K-12 provides an ideal system for exploring this process. Methods and Findings Time-resolved transcript profiles of E. coli K-12 during the initial phase of transition from anaerobic to micro-aerobic conditions revealed a reprogramming of gene expression consistent with a switch from fermentative to respiratory metabolism. The changes in transcript abundance were matched by changes in the abundances of selected central metabolic proteins. A probabilistic state space model was used to infer the activities of two key regulators, FNR (O2 sensing) and PdhR (pyruvate sensing). The model implied that both regulators were rapidly inactivated during the transition from an anaerobic to a micro-aerobic environment. Analysis of the external metabolome and protein levels suggested that the cultures transit through different physiological states during the process of adaptation, characterized by the rapid inactivation of pyruvate formate-lyase (PFL), a slower induction of pyruvate dehydrogenase complex (PDHC) activity and transient excretion of pyruvate, consistent with the predicted inactivation of PdhR and FNR. Conclusion Perturbation of anaerobic steady-state cultures by introduction of a limited supply of O2 combined with time-resolved transcript, protein and metabolite profiling, and probabilistic modeling has revealed that pyruvate (sensed by PdhR) is a key metabolic signal in coordinating the reprogramming of E. coli K-12 gene expression by working alongside the O2 sensor FNR during transition from anaerobic to micro-aerobic conditions. PMID:21980479

Reprogramming of Escherichia coli K-12 metabolism during the initial phase of transition from an anaerobic to a micro-aerobic environment.

PubMed

Trotter, Eleanor W; Rolfe, Matthew D; Hounslow, Andrea M; Craven, C Jeremy; Williamson, Michael P; Sanguinetti, Guido; Poole, Robert K; Green, Jeffrey

2011-01-01

Many bacteria undergo transitions between environments with differing O₂ availabilities as part of their natural lifestyles and during biotechnological processes. However, the dynamics of adaptation when bacteria experience changes in O₂ availability are understudied. The model bacterium and facultative anaerobe Escherichia coli K-12 provides an ideal system for exploring this process. Time-resolved transcript profiles of E. coli K-12 during the initial phase of transition from anaerobic to micro-aerobic conditions revealed a reprogramming of gene expression consistent with a switch from fermentative to respiratory metabolism. The changes in transcript abundance were matched by changes in the abundances of selected central metabolic proteins. A probabilistic state space model was used to infer the activities of two key regulators, FNR (O₂ sensing) and PdhR (pyruvate sensing). The model implied that both regulators were rapidly inactivated during the transition from an anaerobic to a micro-aerobic environment. Analysis of the external metabolome and protein levels suggested that the cultures transit through different physiological states during the process of adaptation, characterized by the rapid inactivation of pyruvate formate-lyase (PFL), a slower induction of pyruvate dehydrogenase complex (PDHC) activity and transient excretion of pyruvate, consistent with the predicted inactivation of PdhR and FNR. Perturbation of anaerobic steady-state cultures by introduction of a limited supply of O₂ combined with time-resolved transcript, protein and metabolite profiling, and probabilistic modeling has revealed that pyruvate (sensed by PdhR) is a key metabolic signal in coordinating the reprogramming of E. coli K-12 gene expression by working alongside the O₂ sensor FNR during transition from anaerobic to micro-aerobic conditions.

EVALUATION PLAN FOR TWO LARGE-SCALE LANDFILL BIOREACTOR TECHNOLOGIES

EPA Science Inventory

Abstract - Waste Management, Inc., is operating two long-term bioreactor studies at the Outer Loop Landfill in Louisville, KY, including facultative landfill bioreactor and staged aerobic-anaerobic landfill bioreactor demonstrations. A Quality Assurance Project Plan (QAPP) was p...

Mass culture of photobacteria to obtain luciferase

NASA Technical Reports Server (NTRS)

Chappelle, E. W.; Picciolo, G. L.; Rich, E., Jr.

1969-01-01

Inoculating preheated trays containing nutrient agar with photobacteria provides a means for mass culture of aerobic microorganisms in order to obtain large quantities of luciferase. To determine optimum harvest time, growth can be monitored by automated light-detection instrumentation.

Characterization and mitigation of nitrous oxide (N2 O) emissions from partial and full-nitrification BNR processes based on post-anoxic aeration control.

PubMed

Brotto, Ariane Coelho; Li, Huosheng; Dumit, Muriel; Gabarró, Jordi; Colprim, Jesús; Murthy, Sudhir; Chandran, Kartik

2015-11-01

It has been reported that a directional change from anoxic to aerobic conditions is a common trigger for nitrous oxide (N2 O) production by ammonia oxidizing bacteria (AOB). By extension, during anoxic-aerobic cycling, post-anoxic dissolved oxygen (DO) concentrations might likely play a role in the magnitude of N2 O emissions observed. The overall goal of this study was to determine the impact of three select post-anoxic DO concentrations (0.8, 2.0, and 3.0 mg O2 /L) on N2 O emissions from partial-nitrification (PN) and full-nitrification (FN) reactors subjected to anoxic-aerobic cycling and, ultimately, to explore the development of strategies to minimize N2 O emissions from PN and FN based biological nitrogen removal (BNR) processes. Statistically similar N2 O emissions were observed during anoxia for both PN (0.62 ± 0.21% N load) and FN (0.61 ± 0.070% N load) processes. In contrast, N2 O emissions were statistically lower for PN (0.86 ± 0.25% N load) than for FN (4.6 ± 2.8% N load), during the post-anoxic aerobic phase, when compared together for all three post-anoxic DO concentrations. Further, for PN, the highest N2 O emissions were observed at the highest post-anoxic DO concentration of 3.0 mg O2 /L (1.2% N load), likely due to the highest corresponding AOB specific growth rate. In contrast, for FN, the highest N2 O emissions were at the lowest post-anoxic DO concentration of 0.8 mg O2 /L (8.5% N load). The higher emissions from FN process at low DO concentrations were associated with a lag in nitrite oxidizing bacteria activity upon recovery to aerobic conditions. This lag phase contributed to transient nitrite accumulation, and in turn correlated positively to the observed N2 O emissions. Based on our findings, a gradual ramp up in post-anoxic DO concentrations can minimize N2 O emissions during PN-based BNR, whereas a completely different strategy, entailing a rapid increase in post-anoxic DO concentrations can minimize emissions during FN-based BNR operations. © 2015 Wiley Periodicals, Inc.

Cryptic oxygen cycling in anoxic marine zones

PubMed Central

Padilla, Cory C.; Stewart, Frank J.; Ulloa, Osvaldo; Paulmier, Aurélien; Gregori, Gerald; Revsbech, Niels Peter

2017-01-01

Oxygen availability drives changes in microbial diversity and biogeochemical cycling between the aerobic surface layer and the anaerobic core in nitrite-rich anoxic marine zones (AMZs), which constitute huge oxygen-depleted regions in the tropical oceans. The current paradigm is that primary production and nitrification within the oxic surface layer fuel anaerobic processes in the anoxic core of AMZs, where 30–50% of global marine nitrogen loss takes place. Here we demonstrate that oxygenic photosynthesis in the secondary chlorophyll maximum (SCM) releases significant amounts of O2 to the otherwise anoxic environment. The SCM, commonly found within AMZs, was dominated by the picocyanobacteria Prochlorococcus spp. Free O2 levels in this layer were, however, undetectable by conventional techniques, reflecting a tight coupling between O2 production and consumption by aerobic processes under apparent anoxic conditions. Transcriptomic analysis of the microbial community in the seemingly anoxic SCM revealed the enhanced expression of genes for aerobic processes, such as nitrite oxidation. The rates of gross O2 production and carbon fixation in the SCM were found to be similar to those reported for nitrite oxidation, as well as for anaerobic dissimilatory nitrate reduction and sulfate reduction, suggesting a significant effect of local oxygenic photosynthesis on Pacific AMZ biogeochemical cycling. PMID:28716941

The sweet trap in tumors: aerobic glycolysis and potential targets for therapy

PubMed Central

Wang, Liantang; Chen, Shangwu

2016-01-01

Metabolic change is one of the hallmarks of tumor, which has recently attracted a great of attention. One of main metabolic characteristics of tumor cells is the high level of glycolysis even in the presence of oxygen, known as aerobic glycolysis or the Warburg effect. The energy production is much less in glycolysis pathway than that in tricarboxylic acid cycle. The molecular mechanism of a high glycolytic flux in tumor cells remains unclear. A large amount of intermediates derived from glycolytic pathway could meet the biosynthetic requirements of the proliferating cells. Hypoxia-induced HIF-1α, PI3K-Akt-mTOR signaling pathway, and many other factors, such as oncogene activation and tumor suppressor inactivation, drive cancer cells to favor glycolysis over mitochondrial oxidation. Several small molecules targeting glycolytic pathway exhibit promising anticancer activity both in vitro and in vivo. In this review, we will focus on the latest progress in the regulation of aerobic glycolysis and discuss the potential targets for the tumor therapy. PMID:26918353

The sweet trap in tumors: aerobic glycolysis and potential targets for therapy.

PubMed

Yu, Li; Chen, Xun; Wang, Liantang; Chen, Shangwu

2016-06-21

Metabolic change is one of the hallmarks of tumor, which has recently attracted a great of attention. One of main metabolic characteristics of tumor cells is the high level of glycolysis even in the presence of oxygen, known as aerobic glycolysis or the Warburg effect. The energy production is much less in glycolysis pathway than that in tricarboxylic acid cycle. The molecular mechanism of a high glycolytic flux in tumor cells remains unclear. A large amount of intermediates derived from glycolytic pathway could meet the biosynthetic requirements of the proliferating cells. Hypoxia-induced HIF-1α, PI3K-Akt-mTOR signaling pathway, and many other factors, such as oncogene activation and tumor suppressor inactivation, drive cancer cells to favor glycolysis over mitochondrial oxidation. Several small molecules targeting glycolytic pathway exhibit promising anticancer activity both in vitro and in vivo. In this review, we will focus on the latest progress in the regulation of aerobic glycolysis and discuss the potential targets for the tumor therapy.

Use of slow filtration columns to assess oxygen respiration, consumption of dissolved organic carbon, nitrogen transformations, and microbial parameters in hyporheic sediments.

PubMed

Mermillod-Blondin, F; Mauclaire, L; Montuelle, B

2005-05-01

Biogeochemical processes mediated by microorganisms in river sediments (hyporheic sediments) play a key role in river metabolism. Because biogeochemical reactions in the hyporheic zone are often limited to the top few decimetres of sediments below the water-sediment interface, slow filtration columns were used in the present study to quantify biogeochemical processes (uptakes of O2, DOC, and nitrate) and the associated microbial compartment (biomass, respiratory activity, and hydrolytic activity) at a centimetre scale in heterogeneous (gravel and sand) sediments. The results indicated that slow filtration columns recreated properly the aerobic-anaerobic gradient classically observed in the hyporheic zone. O2 and NO3- consumptions (256 +/- 13 microg of O2 per hour and 14.6 +/- 6.1 microg of N-NO3- per hour) measured in columns were in the range of values measured in different river sediments. Slow filtration columns also reproduced the high heterogeneity of the hyporheic zone with the presence of anaerobic pockets in sediments where denitrification and fermentation processes occurred. The respiratory and hydrolytic activities of bacteria were strongly linked with the O2 consumption in the experimental system, highlighting the dominance of aerobic processes in our river sediments. In comparison with these activities, the bacterial biomass (protein content) integrated both aerobic and anaerobic processes and could be used as a global microbial indicator in our system. Finally, slow filtration columns are an appropriate tool to quantify in situ rates of biogeochemical processes and to determine the relationship between the microbial compartment and the physico-chemical environment in coarse river sediments.

Assessment of microbial products in the biosorption process of Cu(II) onto aerobic granular sludge: Extracellular polymeric substances contribution and soluble microbial products release.

PubMed

Huang, Linxian; Li, Meilin; Si, Guangchao; Wei, Jinglin; Ngo, Huu Hao; Guo, Wenshan; Xu, Weiying; Du, Bin; Wei, Qin; Wei, Dong

2018-05-18

In the present study, the responses of microbial products in the biosorption process of Cu(II) onto aerobic granular sludge were evaluated by using batch and spectroscopic approaches. Batch experimental data showed that extracellular polymeric substances (EPSs) contributed to Cu(II) removal from an aqueous solution, especially when treating low metal concentrations, whereas soluble microbial products (SMPs) were released under the metal stress during biosorption process. A three-dimensional excitation-emission matrix (3D-EEM) identified four main fluorescence peaks in the EPS, i.e., tryptophan protein-like, aromatic protein-like, humic-like and fulvic acid-like substances, and their fluorescence intensities decreased gradually in the presence of Cu(II) during the sorption process. Particularly, tryptophan protein-like substances quenched the Cu(II) binding to a much higher extent through a static quenching process with less than one class of binding sites. According to the synchronous fluorescence spectra, the whole fluorescence intensity of released SMP samples expressed an increased trend with different degrees along with contact time. Two-dimensional correlation spectroscopy (2D-COS) suggested that the fulvic-like fluorescence fraction might be more susceptible to metal exposure than other fractions. The result of molecular weight distribution demonstrated that the SMPs released from the biosorption process differed significantly according to contact time. The result obtained could provide new insights into the responses of microbial products from aerobic granular sludge with heavy metal treatment. Copyright © 2018. Published by Elsevier Inc.

Optimization of hydraulic shear parameters and reactor configuration in the aerobic granular sludge process.

PubMed

Zhu, Liang; Zhou, Jiaheng; Yu, Haitian; Xu, Xiangyang

2015-01-01

The hydraulic shear acts as an important selection pressure in aerobic sludge granulation. The effects of the hydraulic shear rate and reactor configuration on structural characteristics of aerobic granule in view of the hydromechanics. The hydraulic shear analysis was proposed to overcome the limitation of using superficial gas velocity (SGV) to express the hydraulic shear stress. Results showed that the stronger hydraulic shear stress with SGV above 2.4 cm s(-1) promoted the microbial aggregation, and favoured the structural stability of the granular sludge. According to the hydraulic shear analysis, the total shear rate reached (0.56-2.31)×10(5) s(-1) in the granular reactor with a larger ratio of height to diameter (H/D), and was higher than that in the reactor with smaller H/D, where the sequencing airlift bioreactor with smaller H/D had a high total shear rate under the same SGV. Results demonstrated that the granular reactor could provide a stronger hydraulic shear stress which promotes the formation and structural stability of aerobic granules.

Wet air oxidation induced enhanced biodegradability of distillery effluent.

PubMed

Malik, S N; Saratchandra, T; Tembhekar, P D; Padoley, K V; Mudliar, S L; Mudliar, S N

2014-04-01

The present study reports the feasibility of Wet Air Oxidation (WAO) as a pretreatment option for enhanced biodegradation of complex distillery effluent. Initially, the distillery effluent was pretreated by WAO at different process conditions (pressure, temperature and time) to facilitate enhancement in the biodegradability index (BI = BOD5: COD ratio). The biodegradability of WAO pretreated effluent was evaluated by subjecting it to aerobic biodegradation and anaerobic followed by aerobic biodegradation. Aerobic biodegradation of pretreated effluent with enhanced biodegradability index (BI = 0.4-0.8) showed enhanced COD reduction of up to 67.7%, whereas the untreated effluent (BI = 0.17) indicated poor COD reduction of only 22.5%. Anaerobic followed by aerobic biodegradation of pretreated effluent has shown up to 87.9% COD reduction, while the untreated effluent has shown only 43.1% COD reduction. Bio-kinetic parameters also confirmed the increased rate of bio-oxidation at enhanced BIs. The results indicate that the WAO pretreatment facilitates enhanced bio-oxidation/bio-degradation of complex effluents like the distillery spent wash. Copyright © 2014 Elsevier Ltd. All rights reserved.

Stabilisation of microalgae: Iodine mobilisation under aerobic and anaerobic conditions.

PubMed

Han, Wei; Clarke, William; Pratt, Steven

2015-10-01

Mobilisation of iodine during microalgae stabilisation was investigated, with the view of assessing the potential of stabilised microalgae as an iodine-rich fertiliser. An iodine-rich waste microalgae (0.35 ± 0.05 mg I g(-1) VS(added)) was stabilised under aerobic and anaerobic conditions. Iodine mobilisation was linearly correlated with carbon emission, indicating iodine was in the form of organoiodine. Comparison between iodine and nitrogen mobilisation relative to carbon emission indicated that these elements were, at least in part, housed separately within the cells. After stabilisation, there were 0.22 ± 0.05 and 0.19 ± 0.01 mg g(-1) VS(added) iodine remaining in the solid in the aerobic and anaerobic processed material respectively, meaning 38 ± 5.0% (aerobic) and 50 ± 8.6% (anaerobic) of the iodine were mobilised, and consequently lost from the material. The iodine content of the stabilised material is comparable to the iodine content of some seaweed fertilisers, and potentially satisfies an efficient I-fertilisation dose. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of Aerobic Exercise Training on Mood in People With Traumatic Brain Injury: A Pilot Study.

PubMed

Weinstein, Ali A; Chin, Lisa M K; Collins, John; Goel, Divya; Keyser, Randall E; Chan, Leighton

Exercise training is associated with elevations in mood in patients with various chronic illnesses and disabilities. However, little is known regarding the effect of exercise training on short and long-term mood changes in those with traumatic brain injury (TBI). The purpose of this study was to examine the time course of mood alterations in response to a vigorous, 12-week aerobic exercise training regimen in ambulatory individuals with chronic TBI (>6 months postinjury). Short and long-term mood changes were measured using the Profile of Mood States-Short Form, before and after specific aerobic exercise bouts performed during the 12-week training regimen. Ten subjects with nonpenetrating TBI (6.6 ± 6.8 years after injury) completed the training regimen. A significant improvement in overall mood was observed following 12 weeks of aerobic exercise training (P = .04), with moderate to large effect sizes observed for short-term mood improvements following individual bouts of exercise. Specific improvements in long-term mood state and short-term mood responses following individual exercise sessions were observed in these individuals with TBI. The largest improvement in overall mood was observed at 12 weeks of exercise training, with improvements emerging as early as 4 weeks into the training regimen.

Effect of seed sludge on characteristics and microbial community of aerobic granular sludge.

PubMed

Song, Zhiwei; Pan, Yuejun; Zhang, Kun; Ren, Nanqi; Wang, Aijie

2010-01-01

Aerobic granular sludge was cultivated by using different kinds of seed sludge in sequencing batch airlift reactor. The influence of seed sludge on physical and chemical properties of granular sludge was studied; the microbial community structure was probed by using scanning electron microscope and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that seed sludge played an important role on the formation of aerobic granules. Seed sludge taken from beer wastewater treatment plant (inoculum A) was more suitable for cultivating aerobic granules than that of sludge from municipal wastewater treatment plant (inoculum B). Cultivated with inoculum A, large amount of mature granules formed after 35 days operation, its SVI reached 32.75 mL/g, and SOUR of granular sludge was beyond 1.10 mg/(g x min). By contrast, it needed 56 days obtaining mature granules using inoculum B. DGGE profiles indicated that the dominant microbial species in mature granules were 18 and 11 OTU when inoculum A and B were respectively employed as seed sludge. The sequencing results suggested that dominant species in mature granules cultivated by inoculum A were Paracoccus sp., Devosia hwasunensi, Pseudoxanthomonas sp., while the dominant species were Lactococcus raffinolactis and Pseudomonas sp. in granules developed from inoculum B.

Activated Sludge.

ERIC Educational Resources Information Center

Saunders, F. Michael

1978-01-01

Presents the 1978 literature review of wastewater treatment. This review covers: (1) activated sludge process; (2) process control; (3) oxygen uptake and transfer; (4) phosphorus removal; (5) nitrification; (6) industrial wastewater; and (7) aerobic digestion. A list of 136 references is also presented. (HM)

GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA: AEROBIC BIODEGRADATION REMEDY SCREENING

EPA Science Inventory

Systematically conducted, well-documented treatability studies are an important component of the remedial investigation/feasibility study (KU FS) process and the remedial design/remedial action (RD/RA) process under the Comprehensive Environmental Response, Compensation, and L...

Inhibition kinetics and granular sludge in an ANAMMOX reactor treating mature landfill leachate.

PubMed

Yun, Li; Zhaoming, Zheng; Jun, Li; Baihang, Zhao; Wei, Bian; Yanzhuo, Zhang; Xiujie, Wang

2016-12-01

The present study reports the inhibition kinetics and granular sludge in an anaerobic ammonium oxidation (ANAMMOX) - up-flow anaerobic sludge blanket reactor fed with diluted mature landfill leachate. The activity of ANAMMOX bacteria was inhibited by addition of mature landfill leachate, but gradually adapted to the leachate. The system achieved efficient nitrogen removal during 65-75 d and the average removal efficiencies for NH 4 + -N, NO 2 - -N and total nitrogen (TN) were 96%, 95% and 87%, respectively. ANAMMOX was the main pathway of nitrogen removal in the system, and heterotrophic denitrification occurred simultaneously. In addition, aerobic ammonia oxidation and aerobic nitrite oxidation were active in this system. Inhibition kinetic experiments showed that the NH 4 + -N and NO 2 - -N inhibition concentration threshold of ANAMMOX were 489.03 mg/L and 192.36 mg/L, respectively. ANAMMOX was significantly inhibited by mature landfill leachate, and was completely inhibited when the leachate concentration was 1,450.69 mg/L (calculated in chemical oxygen demand). Thus, the inhibition concentration of substrate and landfill leachate should be considered when applying the ANAMMOX process to landfill leachate. The color of granular sludge ANAMMOX changed from brick-red into a reddish-brown. The particle size increased from small to large, with evident granulation of the ANAMMOX sludge.

EsrE-A yigP Locus-Encoded Transcript-Is a 3′ UTR sRNA Involved in the Respiratory Chain of E. coli

PubMed Central

Xia, Hui; Yang, Xichen; Tang, Qiongwei; Ye, Jiang; Wu, Haizhen; Zhang, Huizhan

2017-01-01

The yigP locus is widely conserved among γ-proteobacteria. Mutation of the yigP locus impacts aerobic growth of Gram-negative bacteria. However, the underlying mechanism of how the yigP locus influences aerobic growth remains largely unknown. Here, we demonstrated that the yigP locus in Escherichia coli encodes two transcripts; the mRNA of ubiquinone biosynthesis protein, UbiJ, and the 3′ untranslated region small regulatory RNA (sRNA), EsrE. EsrE is an independent transcript that is transcribed using an internal promoter of the yigP locus. Surprisingly, we found that both the EsrE sRNA and UbiJ protein were required for Q8 biosynthesis, and were sufficient to rescue the growth defect ascribed to deletion of the yigP locus. Moreover, our data showed that EsrE targeted multiple mRNAs involved in several cellular processes including murein biosynthesis and the tricarboxylic acid cycle. Among these targets, sdhD mRNA that encodes one subunit of succinate dehydrogenase (SDH), was significantly activated. Our findings provided an insight into the important function of EsrE in bacterial adaptation to various environments, as well as coordinating different aspects of bacterial physiology. PMID:28900423

Anoxic control of odour and corrosion from sewer networks.

PubMed

Yang, W; Vollertsen, J; Hvitved-Jacobsen, T

2004-01-01

Anoxic processes can effectively control odour and corrosion in sewer networks. However, the absence of fundamental knowledge on the kinetics of anoxic transformation of sewage prevents the engineering applications of anoxic control in sewers. This paper focuss on a basic understanding of the anoxic transformations needed for a conceptual simulation of the water phase processes. Experiments conducted in batch reactors have shown that nitrite builds up in wastewater during denitrification. Part of the nitrate-reducing biomass is capable of utilizing nitrite after nitrate is depleted. Compared with aerobic transformation, anoxic processes have low values of maximum growth rate of the biomass and also a low endogenous respiration rate. Heterotrophic yield determined under anoxic conditions, at level of 0.25 mmol e-eq (mmol e-eq)(-1), accounted for less than 40% of the corresponding aerobic values.

Development of a scaled-down aerobic fermentation model for scale-up in recombinant protein vaccine manufacturing.

PubMed

Farrell, Patrick; Sun, Jacob; Gao, Meg; Sun, Hong; Pattara, Ben; Zeiser, Arno; D'Amore, Tony

2012-08-17

A simple approach to the development of an aerobic scaled-down fermentation model is presented to obtain more consistent process performance during the scale-up of recombinant protein manufacture. Using a constant volumetric oxygen mass transfer coefficient (k(L)a) for the criterion of a scale-down process, the scaled-down model can be "tuned" to match the k(L)a of any larger-scale target by varying the impeller rotational speed. This approach is demonstrated for a protein vaccine candidate expressed in recombinant Escherichia coli, where process performance is shown to be consistent among 2-L, 20-L, and 200-L scales. An empirical correlation for k(L)a has also been employed to extrapolate to larger manufacturing scales. Copyright © 2012 Elsevier Ltd. All rights reserved.

Repeated sprint ability in soccer players: associations with physiological and neuromuscular factors.

PubMed

Baldi, Marcelo; DA Silva, Juliano F; Buzzachera, Cosme F; Castagna, Carlo; Guglielmo, Luiz G

2017-01-01

The aim of this study was to examine the relationship between repeated sprint ability (RSA, 6×40 m [20+20 m] with 20-s recovery) and neuromuscular and aerobic fitness variables in male collegiate soccer players. Twenty-six players (age 22.5±3.6 years) were tested on separate days for countermovement jump (CMJ), squat jump (SJ), and standing long jump (LJ), and for maximal oxygen consumption (V̇O2max), velocity at onset of blood lactate accumulation (vOBLA), maximal aerobic speed (vV̇O2max), and peak blood lactate concentration (peak [La]). They were also tested for best and mean times on a repeated shuttle sprint ability test. RSA best time (r=-0.73 and r=-0.54) and RSA mean sprint time (r=-0.69 and r=-0.62) were significantly (P<0.01) correlated with LJ and CMJ, respectively. Significant correlations (P<0.05) were also found between RSA mean sprint time and sprint decrement with vOBLA (r=-0.44) and peak [La] (r=0.47), respectively. This study showed that RSA performance had a large to very large association with the individual level of jump performance and to a smaller extent to aerobic fitness variables in male collegiate soccer players. Given this finding, lower limbs' explosive-strength performance should be regarded as a relevant factor for male soccer.

Environmental metabolomics reveal geographic variation in aerobic metabolism and metabolic substrates in Mongolian gerbils (Meriones unguiculatus).

PubMed

Shi, Yao-Long; Chi, Qing-Sheng; Liu, Wei; Fu, He-Ping; Wang, De-Hua

2015-06-01

Mongolian gerbils (Meriones unguiculatus) have a large-scale distribution in northern China. Geographic physiological variations which related to energy and water metabolism are critical to animals' local adaptation and distribution. However, the underlying biochemical mechanism of such variation and its role in adaptation remains largely unknown. We used GC-MS metabolomics approach to investigate the biochemical adaptation of Mongolian gerbils from xeric (desert), transition (desert steppe) and mesic (typical steppe) environments. Gerbils in desert population had lower resting metabolic rate (RMR) and total evaporative water loss (TEWL) than mesic population. Serum metabolomics revealed that concentrations of five tricarboxylic acid cycle intermediates (citrate, cis-aconitate, α-ketoglutarate, fumarate and malate) were lower in desert population than mesic population. Gastrocnemius metabolomics and citrate synthase activity analysis showed a lower concentration of citrate and lower citrate synthase activity in desert population. These findings suggest that desert dwelling gerbils decrease RMR and TEWL via down-regulation of aerobic respiration. Gastrocnemius metabolomics also revealed that there were higher concentrations of glucose and glycolytic intermediates, but lower concentrations of lipids, amino acids and urea in desert population than mesic population. This geographic variation in metabolic substrates may enhance metabolic water production per oxygen molecule for desert population while constraining aerobic respiration to reduce RMR and TEWL. Copyright © 2015 Elsevier Inc. All rights reserved.

Spatial nitrifications of microbial processes during composting of swine, cow and chicken manure

PubMed Central

Wang, Ke; Li, Weiguang; Li, Xiangkun; Ren, Nanqi

2015-01-01

Composting is a widely-used method to recycle the nutrients in livestock manure for agriculture. The spatial stratifications of microbial processes inside the manure particle that determine organic and nitrogen transformation are virtually unclear. Here, we show the evolution of the interior microenvironment of swine, cow and chicken manure by using microelectrodes during forced-aeration composting. Composting has generally been regarded as an aerobic bioprocess, however, the long-existing of a large anoxic zone inside these manures was confirmed during the active phase in this study. The profile of the oxidation–reduction potential dramatically decreased first and then gradually increased. The spatial difference in the ammonia concentration was not significant, but nitrate concentration continuously decreased with depth. The anoxic condition within the manure particle was demonstrated to be a primary cause of the severe ammonia emission and the long composting period. These founding provided a new insight toward “aerobic” composting process and a sound foundation for the development of efficient composting technology. PMID:26442637

Spatial nitrifications of microbial processes during composting of swine, cow and chicken manure

NASA Astrophysics Data System (ADS)

Wang, Ke; Li, Weiguang; Li, Xiangkun; Ren, Nanqi

2015-10-01

Composting is a widely-used method to recycle the nutrients in livestock manure for agriculture. The spatial stratifications of microbial processes inside the manure particle that determine organic and nitrogen transformation are virtually unclear. Here, we show the evolution of the interior microenvironment of swine, cow and chicken manure by using microelectrodes during forced-aeration composting. Composting has generally been regarded as an aerobic bioprocess, however, the long-existing of a large anoxic zone inside these manures was confirmed during the active phase in this study. The profile of the oxidation-reduction potential dramatically decreased first and then gradually increased. The spatial difference in the ammonia concentration was not significant, but nitrate concentration continuously decreased with depth. The anoxic condition within the manure particle was demonstrated to be a primary cause of the severe ammonia emission and the long composting period. These founding provided a new insight toward “aerobic” composting process and a sound foundation for the development of efficient composting technology.

Aerobic digestion reduces the quantity of antibiotic resistance genes in residual municipal wastewater solids

PubMed Central

Burch, Tucker R.; Sadowsky, Michael J.; LaPara, Timothy M.

2012-01-01

Numerous initiatives have been undertaken to circumvent the problem of antibiotic resistance, including the development of new antibiotics, the use of narrow spectrum antibiotics, and the reduction of inappropriate antibiotic use. We propose an alternative but complimentary approach to reduce antibiotic resistant bacteria (ARB) by implementing more stringent technologies for treating municipal wastewater, which is known to contain large quantities of ARB and antibiotic resistance genes (ARGs). In this study, we investigated the ability of conventional aerobic digestion to reduce the quantity of ARGs in untreated wastewater solids. A bench-scale aerobic digester was fed untreated wastewater solids collected from a full-scale municipal wastewater treatment facility. The reactor was operated under semi-continuous flow conditions for more than 200 days at a residence time of approximately 40 days. During this time, the quantities of tet(A), tet(W), and erm(B) decreased by more than 90%. In contrast, intI1 did not decrease, and tet(X) increased in quantity by 5-fold. Following operation in semi-continuous flow mode, the aerobic digester was converted to batch mode to determine the first-order decay coefficients, with half-lives ranging from as short as 2.8 days for tet(W) to as long as 6.3 days for intI1. These results demonstrated that aerobic digestion can be used to reduce the quantity of ARGs in untreated wastewater solids, but that rates can vary substantially depending on the reactor design (i.e., batch vs. continuous-flow) and the specific ARG. PMID:23407455

Aerobic digestion reduces the quantity of antibiotic resistance genes in residual municipal wastewater solids.

PubMed

Burch, Tucker R; Sadowsky, Michael J; Lapara, Timothy M

2013-01-01

Numerous initiatives have been undertaken to circumvent the problem of antibiotic resistance, including the development of new antibiotics, the use of narrow spectrum antibiotics, and the reduction of inappropriate antibiotic use. We propose an alternative but complimentary approach to reduce antibiotic resistant bacteria (ARB) by implementing more stringent technologies for treating municipal wastewater, which is known to contain large quantities of ARB and antibiotic resistance genes (ARGs). In this study, we investigated the ability of conventional aerobic digestion to reduce the quantity of ARGs in untreated wastewater solids. A bench-scale aerobic digester was fed untreated wastewater solids collected from a full-scale municipal wastewater treatment facility. The reactor was operated under semi-continuous flow conditions for more than 200 days at a residence time of approximately 40 days. During this time, the quantities of tet(A), tet(W), and erm(B) decreased by more than 90%. In contrast, intI1 did not decrease, and tet(X) increased in quantity by 5-fold. Following operation in semi-continuous flow mode, the aerobic digester was converted to batch mode to determine the first-order decay coefficients, with half-lives ranging from as short as 2.8 days for tet(W) to as long as 6.3 days for intI1. These results demonstrated that aerobic digestion can be used to reduce the quantity of ARGs in untreated wastewater solids, but that rates can vary substantially depending on the reactor design (i.e., batch vs. continuous-flow) and the specific ARG.

Biosynthesis of polyhydroxyalkanaotes by a novel facultatively anaerobic Vibrio sp. under marine conditions.

PubMed

Numata, Keiji; Doi, Yoshiharu

2012-06-01

Marine bacteria have recently attracted attention as potentially useful candidates for the production of practical materials from marine ecosystems, including the oceanic carbon dioxide cycle. The advantages of using marine bacteria for the biosynthesis of poly(hydroxyalkanoate) (PHA), one of the eco-friendly bioplastics, include avoiding contamination with bacteria that lack salt-water resistance, ability to use filtered seawater as a culture medium, and the potential for extracellular production of PHA, all of which would contribute to large-scale industrial production of PHA. A novel marine bacterium, Vibrio sp. strain KN01, was isolated and characterized in PHA productivity using various carbon sources under aerobic and aerobic-anaerobic marine conditions. The PHA contents of all the samples under the aerobic-anaerobic condition, especially when using soybean oil as the sole carbon source, were enhanced by limiting the amount of dissolved oxygen. The PHA accumulated using soybean oil as a sole carbon source under the aerobic-anaerobic condition contained 14% 3-hydroxypropionate (3HP) and 3% 5-hydroxyvalerate (5HV) units in addition to (R)-3-hydroxybutyrate (3HB) units and had a molecular weight of 42 × 10³ g/mol. The present result indicates that the activity of the beta-oxidation pathway under the aerobic-anaerobic condition is reduced due to a reduction in the amount of dissolved oxygen. These findings have potential for use in controlling the biosynthesis of long main-chain PHA by regulating the activity of the beta-oxidation pathway, which also could be regulated by varying the dissolved oxygen concentration.

Reductions in greenhouse gas (GHG) generation and energy consumption in wastewater treatment plants.

PubMed

Yerushalmi, L; Ashrafi, O; Haghighat, F

2013-01-01

Greenhouse gas (GHG) emission and energy consumption by on-site and off-site sources were estimated in two different wastewater treatment plants that used physical-chemical or biological processes for the removal of contaminants, and an anaerobic digester for sludge treatment. Physical-chemical treatment processes were used in the treatment plant of a locomotive repair factory that processed wastewater at 842 kg chemical oxygen demand per day. Approximately 80% of the total GHG emission was related to fossil fuel consumption for energy production. The emission of GHG was reduced by 14.5% with the recovery of biogas that was generated in the anaerobic digester and its further use as an energy source, replacing fossil fuels. The examined biological treatment system used three alternative process designs for the treatment of effluents from pulp and paper mills that processed wastewater at 2,000 kg biochemical oxygen demand per day. The three designs used aerobic, anaerobic, or hybrid aerobic/anaerobic biological processes for the removal of carbonaceous contaminants, and nitrification/denitrification processes for nitrogen removal. Without the recovery and use of biogas, the aerobic, anaerobic, and hybrid treatment systems generated 3,346, 6,554 and 7,056 kg CO(2)-equivalent/day, respectively, while the generated GHG was reduced to 3,152, 6,051, and 6,541 kg CO(2)-equivalent/day with biogas recovery. The recovery and use of biogas was shown to satisfy and exceed the energy needs of the three examined treatment plants. The reduction of operating temperature of the anaerobic digester and anaerobic reactor by 10°C reduced energy demands of the treatment plants by 35.1, 70.6 and 62.9% in the three examined treatment systems, respectively.

High-speed running and sprinting as an injury risk factor in soccer: Can well-developed physical qualities reduce the risk?

PubMed

Malone, Shane; Owen, Adam; Mendes, Bruno; Hughes, Brian; Collins, Kieran; Gabbett, Tim J

2018-03-01

This study investigated the association between high-speed running (HSR) and sprint running (SR) and injuries within elite soccer players. The impact of intermittent aerobic fitness as measured by the end speed of the 30-15 intermittent fitness test (30-15V IFT ) and high chronic workloads (average 21-day) as potential mediators of injury risk were also investigated. Observational Cohort Study. 37 elite soccer players from one elite squad were involved in a one-season study. Training and game workloads (session-RPE×duration) were recorded in conjunction with external training loads (using global positioning system technology) to measure the HSR (>14.4kmh -1 ) and SR (>19.8kmh -1 ) distance covered across weekly periods during the season. Lower limb injuries were also recorded. Training load and GPS data were modelled against injury data using logistic regression. Odds ratios (OR) were calculated with 90% confidence intervals based on 21-day chronic training load status (sRPE), aerobic fitness, HSR and SR distance with these reported against a reference group. Players who completed moderate HSR (701-750-m: OR: 0.12, 90%CI: 0.08-0.94) and SR distances (201-350-m: OR: 0.54, 90%CI: 0.41-0.85) were at reduced injury risk compared to low HSR (≤674-m) and SR (≤165-m) reference groups. Injury risk was higher for players who experienced large weekly changes in HSR (351-455-m; OR: 3.02; 90%CI: 2.03-5.18) and SR distances (between 75-105-m; OR: 6.12, 90%CI: 4.66-8.29). Players who exerted higher chronic training loads (≥2584 AU) were at significantly reduced risk of injury when they covered 1-weekly HSR distances of 701-750m compared to the reference group of <674m (OR=0.65, 90% CI 0.27-0.89). When intermittent aerobic fitness was considered based on 30-15V IFT performance, players with poor aerobic fitness had a greater risk of injury than players with better-developed aerobic fitness. Exposing players to large and rapid increases in HSR and SR distances increased the odds of injury. However, higher chronic training loads (≥2584 AU) and better intermittent aerobic fitness off-set lower limb injury risk associated with these running distances in elite soccer players. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Oxygen Sensitivity of Anammox and Coupled N-Cycle Processes in Oxygen Minimum Zones

PubMed Central

Kalvelage, Tim; Jensen, Marlene M.; Contreras, Sergio; Revsbech, Niels Peter; Lam, Phyllis; Günter, Marcel; LaRoche, Julie; Lavik, Gaute; Kuypers, Marcel M. M.

2011-01-01

Nutrient measurements indicate that 30–50% of the total nitrogen (N) loss in the ocean occurs in oxygen minimum zones (OMZs). This pelagic N-removal takes place within only ∼0.1% of the ocean volume, hence moderate variations in the extent of OMZs due to global warming may have a large impact on the global N-cycle. We examined the effect of oxygen (O2) on anammox, NH3 oxidation and NO3 − reduction in 15N-labeling experiments with varying O2 concentrations (0–25 µmol L−1) in the Namibian and Peruvian OMZs. Our results show that O2 is a major controlling factor for anammox activity in OMZ waters. Based on our O2 assays we estimate the upper limit for anammox to be ∼20 µmol L−1. In contrast, NH3 oxidation to NO2 − and NO3 − reduction to NO2 − as the main NH4 + and NO2 − sources for anammox were only moderately affected by changing O2 concentrations. Intriguingly, aerobic NH3 oxidation was active at non-detectable concentrations of O2, while anaerobic NO3 − reduction was fully active up to at least 25 µmol L−1 O2. Hence, aerobic and anaerobic N-cycle pathways in OMZs can co-occur over a larger range of O2 concentrations than previously assumed. The zone where N-loss can occur is primarily controlled by the O2-sensitivity of anammox itself, and not by any effects of O2 on the tightly coupled pathways of aerobic NH3 oxidation and NO3 − reduction. With anammox bacteria in the marine environment being active at O2 levels ∼20 times higher than those known to inhibit their cultured counterparts, the oceanic volume potentially acting as a N-sink increases tenfold. The predicted expansion of OMZs may enlarge this volume even further. Our study provides the first robust estimates of O2 sensitivities for processes directly and indirectly connected with N-loss. These are essential to assess the effects of ocean de-oxygenation on oceanic N-cycling. PMID:22216239

Microbiological sampling of swine carcasses: a comparison of data obtained by swabbing with medical gauze and data collected routinely by excision at Swedish abattoirs.

PubMed

Lindblad, M

2007-09-15

Swab sample data from a 13-month microbiological baseline study of swine carcasses at Swedish abattoirs were combined with excision sample data collected routinely at five abattoirs. The aim was to compare the numbers of total aerobic counts, Enterobacteriaceae, and Escherichia coli, recovered by swabbing four carcass sites with gauze (total area 400 cm2) with those obtained by excision at equivalent sites (total area 20 cm2). The results are considered in relation to the process hygiene criteria that are stated in Commission Regulation (EC) No 2073/2005. These criteria apply only to destructive sampling of total aerobic counts and Enterobacteriaceae, but alternative sampling schemes, as well as alternative indicator organisms such as E. coli, are allowed if equivalent guarantees of food safety can be provided. Swab sampling resulted in higher mean log numbers of total aerobic counts at four of the five abattoirs, compared with excision, and lower or equal standard deviations at all abattoirs. The percentage of swab and excision samples positive for Enterobacteriaceae at the different abattoirs ranged from 68 to 100% and 15 to 24%, respectively. Similarly, the percentages of swab samples that were positive for E. coli were higher than the percentages of positive excision samples (range 52 to 84% and 3 to 14%, respectively). Due to the low percentage of positive excision results, the mean log numbers of Enterobacteriaceae and E. coli were only compared at two and one abattoirs, respectively, using log probability regression to substitute censored observations. Higher mean log numbers of Enterobacteriaceae were recovered by swabbing compared with excision at one abattoir, whereas the numbers of Enterobacteriaceae and E. coli did not differ significantly between sampling methods at one abattoir. This study suggests that the same process hygiene criteria as those stipulated for excision can be used for swabbing with gauze without compromising food safety. For monitoring of low numbers of Enterobacteriaceae and E. coli, like those found on swine carcasses at Swedish abattoirs, the results also show that swabbing of a relatively large area is superior to excision of a smaller area.

Aerobic mitochondria of parasitic protists: Diverse genomes and complex functions.

PubMed

Zíková, Alena; Hampl, Vladimír; Paris, Zdeněk; Týč, Jiří; Lukeš, Julius

In this review the main features of the mitochondria of aerobic parasitic protists are discussed. While the best characterized organelles are by far those of kinetoplastid flagellates and Plasmodium, we also consider amoebae Naegleria and Acanthamoeba, a ciliate Ichthyophthirius and related lineages. The simplistic view of the mitochondrion as just a power house of the cell has already been abandoned in multicellular organisms and available data indicate that this also does not apply for protists. We discuss in more details the following mitochondrial features: genomes, post-transcriptional processing, translation, biogenesis of iron-sulfur complexes, heme metabolism and the electron transport chain. Substantial differences in all these core mitochondrial features between lineages are compatible with the view that aerobic protists harbor organelles that are more complex and flexible than previously appreciated. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of alkyl side chain location and cyclicity on the aerobic biotransformation of naphthenic acids.

PubMed

Misiti, Teresa M; Tezel, Ulas; Pavlostathis, Spyros G

2014-07-15

Aerobic biodegradation of naphthenic acids is of importance to the oil industry for the long-term management and environmental impact of process water and wastewater. The effect of structure, particularly the location of the alkyl side chain as well as cyclicity, on the aerobic biotransformation of 10 model naphthenic acids (NAs) was investigated. Using an aerobic, mixed culture, enriched with a commercial NA mixture (NA sodium salt; TCI Chemicals), batch biotransformation assays were conducted with individual model NAs, including eight 8-carbon isomers. It was shown that NAs with a quaternary carbon at the α- or β-position or a tertiary carbon at the β- and/or β'-position are recalcitrant or have limited biodegradability. In addition, branched NAs exhibited lag periods and lower degradation rates than nonbranched or simple cyclic NAs. Two NA isomers used in a closed bottle, aerobic biodegradation assay were mineralized, while 21 and 35% of the parent compound carbon was incorporated into the biomass. The NA biodegradation probability estimated by two widely used models (BIOWIN 2 and 6) and a recently developed model (OCHEM) was compared to the biodegradability of the 10 model NAs tested in this study as well as other related NAs. The biodegradation probability estimated by the OCHEM model agreed best with the experimental data and was best correlated with the measured NA biodegradation rate.

The relationship between sustained attention and aerobic fitness in a group of young adults.

PubMed

Ciria, Luis F; Perakakis, Pandelis; Luque-Casado, Antonio; Morato, Cristina; Sanabria, Daniel

2017-01-01

A growing set of studies has shown a positive relationship between aerobic fitness and a broad array of cognitive functions. However, few studies have focused on sustained attention, which has been considered a fundamental cognitive process that underlies most everyday activities. The purpose of this study was to investigate the role of aerobic fitness as a key factor in sustained attention capacities in young adults. Forty-four young adults (18-23 years) were divided into two groups as a function of the level of aerobic fitness (high-fit and low-fit). Participants completed the Psychomotor Vigilance Task (PVT) and an oddball task where they had to detect infrequent targets presented among frequent non-targets. The analysis of variance (ANOVA) showed faster responses for the high-fit group than for the low-fit group in the PVT, replicating previous accounts. In the oddball task, the high-fit group maintained their accuracy (ACC) rate of target detection over time, while the low-fit group suffered a significant decline of response ACC throughout the task. Importantly, the results show that the greater sustained attention capacity of high-fit young adults is not specific to a reaction time (RT) sustained attention task like the PVT, but it is also evident in an ACC oddball task. In sum, the present findings point to the important role of aerobic fitness on sustained attention capacities in young adults.

Techno-economic evaluation of the application of ozone-oxidation in a full-scale aerobic digestion plant.

PubMed

Chiavola, Agostina; D'Amato, Emilio; Gori, Riccardo; Lubello, Claudio; Sirini, Piero

2013-04-01

This paper deals with the application of the ozone-oxidation in a full scale aerobic sludge digester. Ozonation was applied continuously to a fraction of the biological sludge extracted from the digestion unit; the ozonated sludge was then recirculated to the same digester. Three different ozone flow rates were tested (60,500 and 670g O3 h(-1)) and their effects evaluated in terms of variation of the total and soluble fractions of COD, nitrogen and phosphorous, of total and volatile suspended solids concentrations and Sludge Volume Index in the aerobic digestion unit. During the 7-month operation of the ozonation process, it was observed an appreciable improvement of the aerobic digestion efficiency (up to about 20% under the optimal conditions) and of the sludge settleability properties. These results determined an average reduction of about 60% in the biological sludge extracted from the plant and delivered to final disposal. A thorough economic analysis showed that this reduction allowed to achieve a significant cost saving for the plant with respect to the previous years operated without ozonation. Furthermore, it was determined the threshold disposal cost above which implementation of the ozone oxidation in the aerobic digestion units of similar WWTPs becomes economically convenient (about 60€t(-1) of sludge). Copyright © 2013 Elsevier Ltd. All rights reserved.

An obligately aerobic soil bacterium activates fermentative hydrogen production to survive reductive stress during hypoxia.

PubMed

Berney, Michael; Greening, Chris; Conrad, Ralf; Jacobs, William R; Cook, Gregory M

2014-08-05

Oxygen availability is a major factor and evolutionary force determining the metabolic strategy of bacteria colonizing an environmental niche. In the soil, conditions can switch rapidly between oxia and anoxia, forcing soil bacteria to remodel their energy metabolism accordingly. Mycobacterium is a dominant genus in the soil, and all its species are obligate aerobes. Here we show that an obligate aerobe, the soil actinomycete Mycobacterium smegmatis, adopts an anaerobe-type strategy by activating fermentative hydrogen production to adapt to hypoxia. This process is controlled by the two-component system DosR-DosS/DosT, an oxygen and redox sensor that is well conserved in mycobacteria. We show that DosR tightly regulates the two [NiFe]-hydrogenases: Hyd3 (MSMEG_3931-3928) and Hyd2 (MSMEG_2719-2718). Using genetic manipulation and high-sensitivity GC, we demonstrate that Hyd3 facilitates the evolution of H2 when oxygen is depleted. Combined activity of Hyd2 and Hyd3 was necessary to maintain an optimal NAD(+)/NADH ratio and enhanced adaptation to and survival of hypoxia. We demonstrate that fermentatively-produced hydrogen can be recycled when fumarate or oxygen become available, suggesting Mycobacterium smegmatis can switch between fermentation, anaerobic respiration, and aerobic respiration. Hydrogen metabolism enables this obligate aerobe to rapidly meet its energetic needs when switching between microoxic and anoxic conditions and provides a competitive advantage in low oxygen environments.

Effect of packing material on organic matter removal efficiency in an anaerobic-aerobic baffled bioreactor.

PubMed

Tabla-Hernandez, Jacobo; Lopez-Galvan, Edgar

2018-04-01

The aim of the present work was to study the effect of packing material on the organic matter removal efficiency (OMRE) in an anaerobic-aerobic baffled bioreactor (AAB). For this purpose, two different experiments were conducted with two types of packing material: activated carbon (AC) particles and polyurethane foam (PF). The system consisted of two treatments; the first one was anaerobic, where hydrolysis, acetogenesis and methanogenesis took place. In anaerobic chambers, there were no packing materials and the operating conditions were the same in both experiments. The second treatment was aerobic and both materials were placed at different times as a bedding. The parameters measured were chemical oxygen demand (COD), dissolved chemical oxygen demand (COD d ), total organic carbon (TOC), nitrate concentration (NO 3 - ), ammonium concentration (NH 4 + ), electric conductivity (σ), alkalinity (Alky) and hydrogen potential (pH). Paired t-Student test showed that there was no significant difference in the OMRE in anaerobic treatment, whereas there was in aerobic treatment, due to the effect of packing material. NH 4 + and NO 3 - showed a negative Pearson correlation in both experiments, indicating the presence of the nitrification process in the aerobic chamber. AAB packed with PF had better performance at obtaining an OMRE of around 63%, whereas AAB packed with AC presented an OMRE of around 51%.

Intracellular Accumulation of Glycine in Polyphosphate-Accumulating Organisms in Activated Sludge, a Novel Storage Mechanism under Dynamic Anaerobic-Aerobic Conditions

PubMed Central

Nguyen, Hien Thi Thu; Kristiansen, Rikke; Vestergaard, Mette; Wimmer, Reinhard

2015-01-01

Dynamic anaerobic-aerobic feast-famine conditions are applied to wastewater treatment plants to select polyphosphate-accumulating organisms to carry out enhanced biological phosphorus removal. Acetate is a well-known substrate to stimulate this process, and here we show that different amino acids also are suitable substrates, with glycine as the most promising. 13C-labeled glycine and nuclear magnetic resonance (NMR) were applied to investigate uptake and potential storage products when activated sludge was fed with glycine under anaerobic conditions. Glycine was consumed by the biomass, and the majority was stored intracellularly as free glycine and fermentation products. Subsequently, in the aerobic phase without addition of external substrate, the stored glycine was consumed. The uptake of glycine and oxidation of intracellular metabolites took place along with a release and uptake of orthophosphate, respectively. Fluorescence in situ hybridization combined with microautoradiography using 3H-labeled glycine revealed uncultured actinobacterial Tetrasphaera as a dominant glycine consumer. Experiments with Tetrasphaera elongata as representative of uncultured Tetrasphaera showed that under anaerobic conditions it was able to take up labeled glycine and accumulate this and other labeled metabolites to an intracellular concentration of approximately 4 mM. All components were consumed under subsequent aerobic conditions. Intracellular accumulation of amino acids seems to be a novel storage strategy for polyphosphate-accumulating bacteria under dynamic anaerobic-aerobic feast-famine conditions. PMID:25956769

Microbiological Spoilage of Dairy Products

NASA Astrophysics Data System (ADS)

Ledenbach, Loralyn H.; Marshall, Robert T.

The wide array of available dairy foods challenges the microbiologist, engineer, and technologist to find the best ways to prevent the entry of microorganisms, destroy those that do get in along with their enzymes, and prevent the growth and activities of those that escape processing treatments. Troublesome spoilage microorganisms include aerobic psychrotrophic Gram-negative bacteria, yeasts, molds, heterofermentative lactobacilli, and spore-forming bacteria. Psychrotrophic bacteria can produce large amounts of extracellular hydrolytic enzymes, and the extent of recontamination of pasteurized fluid milk products with these bacteria is a major determinant of their shelf life. Fungal spoilage of dairy foods is manifested by the presence of a wide variety of metabolic by-products, causing off-odors and flavors, in addition to visible changes in color or texture.

Identification of inorganic and organic species of phosphorus and its bio-availability in nitrifying aerobic granular sludge.

PubMed

Huang, Wenli; Cai, Wei; Huang, He; Lei, Zhongfang; Zhang, Zhenya; Tay, Joo Hwa; Lee, Duu-Jong

2015-01-01

Phosphorus (P) recovery from sewage sludge is necessary for a sustainable development of the environment and thus the society due to gradual depletion of non-renewable P resources. Aerobic granular sludge is a promising biotechnology for wastewater treatment, which could achieve P-rich granules during simultaneous nitrification and denitrification processes. This study aimed to disclose the changes in inorganic and organic P species and their correlation with P mobility and bio-availability in aerobic granules. Two identical square reactors were used to cultivate aerobic granules, which were operated for 120 days with influent ammonia nitrogen (NH₄-N) of 100 mg/L before day 60 and then increased to 200 mg/L during the subsequent 60 days (chemical oxygen demand (COD) was kept constant at 600 mg/L). The aerobic granules exhibited excellent COD removal and nitrification efficiency. Results showed that inorganic P (IP) was about 61.4-67.7% of total P (TP) and non-apatite inorganic P (NAIP) occupied 61.9-70.2% of IP in the granules. The enrichment amount of NAIP and apatite P (AP) in the granules had strongly positive relationship with the contents of metal ions, i.e. Fe and Ca, respectively accumulated in the granules. X-ray diffraction (XRD) analysis and solution index calculation demonstrated that hydroxyapatite (Ca₅(PO₄)₃(OH)) and iron phosphate (Fe₇(PO₄)₆) were the major P minerals in the granules. Organic P (OP) content maintained around 7.5 mg per gram of biomass in the aerobic granules during the 120 days' operation. Monoester phosphate (21.8% of TP in extract), diester phosphate (1.8%) and phosphonate (0.1%) were identified as OP species by Phosphorus-31 nuclear magnetic resonance (³¹P NMR). The proportion of NAIP + OP to TP was about 80% in the granules, implying high potentially mobile and bio-available P was stored in the nitrifying aerobic granules. The present results provide a new insight into the characteristics of P species in aerobic granules, which could be helpful for developing P removal and recovery techniques through biological wastewater treatment.

Removal of pharmaceutical and personal care products (PPCPs) under nitrifying and denitrifying conditions.

PubMed

Suarez, Sonia; Lema, Juan M; Omil, Francisco

2010-05-01

The contribution of volatilization, sorption and transformation to the removal of 16 Pharmaceutical and Personal Care Products (PPCPs) in two lab-scale conventional activated sludge reactors, working under nitrifying (aerobic) and denitrifying (anoxic) conditions for more than 1.5 years, have been assessed. Pseudo-first order biological degradation rate constants (k(biol)) were calculated for the selected compounds in both reactors. Faster degradation kinetics were measured in the nitrifying reactor compared to the denitrifying system for the majority of PPCPs. Compounds could be classified according to their k(biol) into very highly (k(biol)>5Lg(SS)(-1)d(-1)), highly (175%) and anoxic (>65%) conditions, whereas naproxen (NPX), ethinylestradiol (EE2), roxithromycin (ROX) and erythromycin (ERY) were only significantly transformed in the aerobic reactor (>80%). The anti-depressant citalopram (CTL) was moderately biotransformed under both, aerobic and anoxic conditions (>60% and >40%, respectively). Some compounds, as carbamazepine (CBZ), diazepam (DZP), sulfamethoxazole (SMX) and trimethoprim (TMP), manifested high resistance to biological transformation. Solids Retention Time (SRT(aerobic) >50d and <50d; SRT(anoxic) >20d and <20d) had a slightly positive effect on the removal of FLX, NPX, CTL, EE2 and natural estrogens (increase in removal efficiencies <10%). Removal of diclofenac (DCF) in the aerobic reactor was positively affected by the development of nitrifying biomass and increased from 0% up to 74%. Similarly, efficient anoxic transformation of ibuprofen (75%) was observed after an adaptation period of 340d. Temperature (16-26 degrees C) only had a slight effect on the removal of CTL which increased in 4%.

Cu-catalyzed esterification reaction via aerobic oxygenation and C-C bond cleavage: an approach to α-ketoesters.

PubMed

Zhang, Chun; Feng, Peng; Jiao, Ning

2013-10-09

The Cu-catalyzed novel aerobic oxidative esterification reaction of 1,3-diones for the synthesis of α-ketoesters has been developed. This method combines C-C σ-bond cleavage, dioxygen activation and oxidative C-H bond functionalization, as well as provides a practical, neutral, and mild synthetic approach to α-ketoesters which are important units in many biologically active compounds and useful precursors in a variety of functional group transformations. A plausible radical process is proposed on the basis of mechanistic studies.

Niche and neutral processes both shape community structure in parallelized, aerobic, single carbon-source enrichments

DOE Data Explorer

Flynn, Theodore M.; Koval, Jason C.; Greenwald, Stephanie M.; Owens, Sarah M.; Kemner, Kenneth M.; Antonopoulos, Dionysios A.

2017-01-01

We present DNA sequence data in FASTA-formatted files from aerobic environmental microcosms inoculated with a sole carbon source. DNA sequences are of 16S rRNA genes present in DNA extracted from each microcosm along with the environmental samples (soil, water) used to inoculate them. These samples were sequenced using the Illumina MiSeq platform at the Environmental Sample Preparation and Sequencing Facility at Argonne National Laboratory. This data is compatible with standard microbiome analysis pipelines (e.g., QIIME, mothur, etc.).

Aerobic Exercise for Reducing Migraine Burden: Mechanisms, Markers, and Models of Change Processes

PubMed Central

Irby, Megan B.; Bond, Dale S.; Lipton, Richard B.; Nicklas, Barbara; Houle, Timothy T.; Penzien, Donald B.

2016-01-01

Background Engagement in regular exercise routinely is recommended as an intervention for managing and preventing migraine, and yet empirical support is far from definitive. We possess at best a weak understanding of how aerobic exercise and resulting change in aerobic capacity influence migraine, let alone the optimal parameters for exercise regimens as migraine therapy (eg, who will benefit, when to prescribe, optimal types, and doses/intensities of exercise, level of anticipated benefit). These fundamental knowledge gaps critically limit our capacity to deploy exercise as an intervention for migraine. Overview Clear articulation of the markers and mechanisms through which aerobic exercise confers benefits for migraine would prove invaluable and could yield insights on migraine pathophysiology. Neurovascular and neuroinflammatory pathways, including an effect on obesity or adiposity, are obvious candidates for study given their role both in migraine as well as the changes known to accrue with regular exercise. In addition to these biological pathways, improvements in aerobic fitness and migraine alike also are mediated by changes in psychological and sociocognitive factors. Indeed a number of specific mechanisms and pathways likely are operational in the relationship between exercise and migraine improvement, and it remains to be established whether these pathways operate in parallel or synergistically. As heuristics that might conceptually benefit our research programs here forward, we: (1) provide an extensive listing of potential mechanisms and markers that could account for the effects of aerobic exercise on migraine and are worthy of empirical exploration and (2) present two exemplar conceptual models depicting pathways through which exercise may serve to reduce the burden of migraine. Conclusion Should the promise of aerobic exercise as a feasible and effective migraine therapy be realized, this line of endeavor stands to benefit migraineurs (including the many who presently remain suboptimally treated) by providing a new therapeutic avenue as an alternative or augmentative compliment to established interventions for migraine. PMID:26643584

Treatment of old landfill leachate with high ammonium content using aerobic granular sludge.

PubMed

Ren, Yanan; Ferraz, Fernanda; Kang, Abbass Jafari; Yuan, Qiuyan

2017-01-01

Aerobic granular sludge has become an attractive alternative to the conventional activated sludge due to its high settling velocity, compact structure, and higher tolerance to toxic substances and adverse conditions. Aerobic granular sludge process has been studied intensively in the treatment of municipal and industrial wastewater. However, information on leachate treatment using aerobic granular sludge is very limited. This study investigated the treatment performance of old landfill leachate with different levels of ammonium using two aerobic sequencing batch reactors (SBR): an activated sludge SBR (ASBR) and a granular sludge SBR (GSBR). Aerobic granules were successfully developed using old leachate with low ammonium concentration (136 mg L -1  NH 4 + -N). The GSBR obtained a stable chemical oxygen demand (COD) removal of 70% after 15 days of operation; while the ASBR required a start-up of at least 30 days and obtained unstable COD removal varying from 38 to 70%. Ammonium concentration was gradually increased in both reactors. Increasing influent ammonium concentration to 225 mg L -1  N, the GSBR removed 73 ± 8% of COD; while COD removal of the ASBR was 59 ± 9%. The GSBR was also more efficient than the ASBR for nitrogen removal. The granular sludge could adapt to the increasing concentrations of ammonium, achieving 95 ± 7% removal efficiency at a maximum influent concentration of 465 mg L -1  N. Ammonium removal of 96 ± 5% was obtained by the ASBR when it was fed with a maximum of 217 mg L -1  NH 4 + -N. However, the ASBR was partially inhibited by free-ammonia and nitrite accumulation rate increased up to 85%. Free-nitrous acid and the low biodegradability of organic carbon were likely the main factors affecting phosphorus removal. The results from this research suggested that aerobic granular sludge have advantage over activated sludge in leachate treatment.

Aerobic Exercise for Reducing Migraine Burden: Mechanisms, Markers, and Models of Change Processes.

PubMed

Irby, Megan B; Bond, Dale S; Lipton, Richard B; Nicklas, Barbara; Houle, Timothy T; Penzien, Donald B

2016-02-01

Engagement in regular exercise routinely is recommended as an intervention for managing and preventing migraine, and yet empirical support is far from definitive. We possess at best a weak understanding of how aerobic exercise and resulting change in aerobic capacity influence migraine, let alone the optimal parameters for exercise regimens as migraine therapy (eg, who will benefit, when to prescribe, optimal types, and doses/intensities of exercise, level of anticipated benefit). These fundamental knowledge gaps critically limit our capacity to deploy exercise as an intervention for migraine. Clear articulation of the markers and mechanisms through which aerobic exercise confers benefits for migraine would prove invaluable and could yield insights on migraine pathophysiology. Neurovascular and neuroinflammatory pathways, including an effect on obesity or adiposity, are obvious candidates for study given their role both in migraine as well as the changes known to accrue with regular exercise. In addition to these biological pathways, improvements in aerobic fitness and migraine alike also are mediated by changes in psychological and sociocognitive factors. Indeed a number of specific mechanisms and pathways likely are operational in the relationship between exercise and migraine improvement, and it remains to be established whether these pathways operate in parallel or synergistically. As heuristics that might conceptually benefit our research programs here forward, we: (1) provide an extensive listing of potential mechanisms and markers that could account for the effects of aerobic exercise on migraine and are worthy of empirical exploration and (2) present two exemplar conceptual models depicting pathways through which exercise may serve to reduce the burden of migraine. Should the promise of aerobic exercise as a feasible and effective migraine therapy be realized, this line of endeavor stands to benefit migraineurs (including the many who presently remain suboptimally treated) by providing a new therapeutic avenue as an alternative or augmentative compliment to established interventions for migraine. © 2015 American Headache Society.

Bacterial and fungal core microbiomes associated with small grain silages during ensiling and aerobic spoilage.

PubMed

Duniere, Lysiane; Xu, Shanwei; Long, Jin; Elekwachi, Chijioke; Wang, Yuxi; Turkington, Kelly; Forster, Robert; McAllister, Tim A

2017-03-03

Describing the microbial populations present in small grain silage and understanding their changes during ensiling is of interest for improving the nutrient value of these important forage crops. Barley, oat and triticale forages as well as an intercropped mixture of the 3 crops were harvested and ensiled in mini silos for a period of 90 days, followed by 14 days of aerobic exposure. Changes in fermentation characteristics and nutritive value were assessed in terminal silages and bacterial and fungal communities during ensiling and aerobic exposure were described using 16S and 18S rDNA sequencing, respectively. All small grain silages exhibited chemical traits that were associated with well ensiled forages, such as low pH value (4.09 ± 0.28) and high levels of lactic acid (59.8 ± 14.59 mg/g DM). The number of microbial core genome operational taxonomic units (OTUs) decreased with time of ensiling. Taxonomic bacterial community profiles were dominated by the Lactobacillales after fermentation, with a notable increase in Bacillales as a result of aerobic exposure. Diversity of the fungal core microbiome was shown to also be reduced during ensiling. Operational taxonomic units assigned to filamentous fungi were found in the core microbiome at ensiling and after aerobic exposure, whereas the Saccharomycetales were the dominate yeast population after 90 days of ensiling and aerobic exposure. Bacterial and fungal orders typically associated with silage spoilage were identified in the core microbiome after aerobic exposure. Next Generation Sequencing was successfully used to describe bacterial communities and the first record of fungal communities throughout the process of ensiling and utilization. Adequately describing the microbial ecology of silages could lead to improved ensiling practices and the selection of silage inoculants that act synergistically with the natural forage microbiome.

Assessing carbon and nitrogen removal in a novel anoxic-aerobic cyanobacterial-bacterial photobioreactor configuration with enhanced biomass sedimentation.

PubMed

de Godos, I; Vargas, V A; Guzmán, H O; Soto, R; García, B; García, P A; Muñoz, R

2014-09-15

The carbon and nitrogen removal potential of an innovative anoxic-aerobic photobioreactor configuration operated with both internal and external recyclings was evaluated under different cyanobacterial-bacterial sludge residence times (9-31 days) during the treatment of wastewaters with low C/N ratios. Under optimal operating conditions, the two-stage photobioreactor was capable of providing organic carbon and nitrogen removals over 95% and 90%, respectively. The continuous biomass recycling from the settler resulted in the enrichment and predominance of rapidly-settling cyanobacterial-bacterial flocs and effluent suspended solid concentrations lower than 35 mg VSS L(-1). These flocs exhibited sedimentation rates of 0.28-0.42 m h(-1) but sludge volumetric indexes of 333-430 ml/g. The decoupling between the hydraulic retention time and sludge retention time mediated by the external recycling also avoided the washout of nitrifying bacteria and supported process operation at biomass concentrations of 1000-1500 mg VSS L(-1). The addition of additional NaHCO3 to the process overcame the CO2 limitation resulting from the intense competition for inorganic carbon between cyanobacteria and nitrifying bacteria in the photobioreactor, which supported the successful implementation of a nitrification-denitrification process. Unexpectedly, this nitrification-denitrification process occurred both simultaneously in the photobioreactor alone (as a result of the negligible dissolved oxygen concentrations) and sequentially in the two-stage anoxic-aerobic configuration with internal NO3(-)/NO2(-) recycling. Copyright © 2014 Elsevier Ltd. All rights reserved.

Aerobic granulation in a sequencing batch reactor (SBR) for industrial wastewater treatment.

PubMed

Inizan, M; Freval, A; Cigana, J; Meinhold, J

2005-01-01

Aerobic granulation seems to be an a attractive process for COD removal from industrial wastewater, characterised by a high content of soluble organic compounds. In order to evaluate the practical aspects of the process, comparative experimental tests are performed on synthetic and on industrial wastewater, originating from pharmaceutical industry. Two pilot plants are operated as sequencing batch bubble columns. Focus was put on the feasibility of the process for high COD removal and on its operational procedure. For both wastewaters, a rapid formation of aerobic granules is observed along with a high COD removal rate. Granule characteristics are quite similar with respect to the two types of wastewater. It seems that filamentous bacteria are part of the granule structure and that phosphorus precipitation can play an important role in granule formation. For both wastewaters similar removal performances for dissolved biodegradable COD are observed (> 95%). However, a relatively high concentration of suspended solids in the outlet deteriorates the performance with regard to total COD removal. Biomass detachment seems to play a non-negligible role in the current set-up. After a stable operational phase the variation of the pharmaceutical wastewater caused a destabilisation and loss of the granules, despite the control for balanced nutrient supply. The first results with real industrial wastewater demonstrate the feasibility of this innovative process. However, special attention has to be paid to the critical aspects such as granule stability as well as the economic competitiveness, which both will need further investigation and evaluation.

The effects of manganese oxide octahedral molecular sieve chitosan microspheres on sludge bacterial community structures during sewage biological treatment.

PubMed

Pan, Fei; Liu, Wen; Yu, Yang; Yin, Xianze; Wang, Qingrong; Zheng, Ziyan; Wu, Min; Zhao, Dongye; Zhang, Qiu; Lei, Xiaoman; Xia, Dongsheng

2016-11-21

This study examines the effects of manganese oxide octahedral molecular sieve chitosan microspheres (Fe 3 O 4 @OMS-2@CTS) on anaerobic and aerobic microbial communities during sewage biological treatment. The addition of Fe 3 O 4 @OMS-2@CTS (0.25 g/L) resulted in enhanced levels of operational performance for decolourization dye X-3B. However, degradation dye X-3B inhibition in the presence of Fe 3 O 4 @OMS-2@CTS was recorded as greater than or equal to 1.00 g/L. Illumina MiSeq high throughput sequencing of the 16 S rRNA gene showed that 108 genera were observed during the anaerobic process, while only 71 genera were observed during the aerobic process. The largest genera (Aequorivita) decreased from 21.14% to 12.65% and the Pseudomonas genera increased from 10.57% to 12.96% according to the abundance in the presence of 0.25 g/L Fe 3 O 4 @OMS-2@CTS during the anaerobic process. The largest Gemmatimonas genera decreased from 21.46% to 11.68% and the Isosphaerae genera increased from 5.8% to 11.98% according to the abundance in the presence of 0.25 g/L Fe 3 O 4 @OMS-2@CTS during the aerobic process. Moreover, the X-ray photoelectron spectroscopy results show that the valence states of Mn and Fe in Fe 3 O 4 @OMS-2@CTS changed during sewage biological treatment.

Geographic and seasonal variation of dissolved methane and aerobic methane oxidation in Alaskan lakes

DOE PAGES

Martinez-Cruz, K.; Sepulveda-Jauregui, A.; Walter Anthony, K.; ...

2015-08-04

Methanotrophic bacteria play an important role oxidizing a significant fraction of methane (CH 4) produced in lakes. Aerobic CH 4 oxidation depends mainly on lake CH 4 and oxygen (O 2) concentrations, in such a manner that higher MO rates are usually found at the oxic/anoxic interface, where both molecules are present. MO also depends on temperature, and via methanogenesis, on organic carbon input to lakes, including from thawing permafrost in thermokarst (thaw)-affected lakes. Given the large variability in these environmental factors, CH 4 oxidation is expected to be subject to large seasonal and geographic variations, which have been scarcelymore » reported in the literature. In the present study, we measured CH 4 oxidation rates in 30 Alaskan lakes along a north-south latitudinal transect during winter and summer with a new field laser spectroscopy method. Additionally, we measured dissolved CH 4 and O 2 concentrations. Here, we found that in the winter, aerobic CH 4 oxidation was mainly controlled by the dissolved O 2 concentration, while in the summer it was controlled primarily by the CH 4 concentration, which was scarce compared to dissolved O 2. The permafrost environment of the lakes was identified as another key factor. Thermokarst (thaw) lakes formed in yedoma-type permafrost had significantly higher CH 4 oxidation rates compared to other thermokarst and non-thermokarst lakes formed in non-yedoma permafrost environments. As thermokarst lakes formed in yedoma-type permafrost have been identified to receive large quantities of terrestrial organic carbon from thaw and subsidence of the surrounding landscape into the lake, confirming the strong coupling between terrestrial and aquatic habitats and its influence on CH 4 cycling.« less

Geographic and seasonal variation of dissolved methane and aerobic methane oxidation in Alaskan lakes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martinez-Cruz, K.; Sepulveda-Jauregui, A.; Walter Anthony, K.

Methanotrophic bacteria play an important role oxidizing a significant fraction of methane (CH 4) produced in lakes. Aerobic CH 4 oxidation depends mainly on lake CH 4 and oxygen (O 2) concentrations, in such a manner that higher MO rates are usually found at the oxic/anoxic interface, where both molecules are present. MO also depends on temperature, and via methanogenesis, on organic carbon input to lakes, including from thawing permafrost in thermokarst (thaw)-affected lakes. Given the large variability in these environmental factors, CH 4 oxidation is expected to be subject to large seasonal and geographic variations, which have been scarcelymore » reported in the literature. In the present study, we measured CH 4 oxidation rates in 30 Alaskan lakes along a north-south latitudinal transect during winter and summer with a new field laser spectroscopy method. Additionally, we measured dissolved CH 4 and O 2 concentrations. Here, we found that in the winter, aerobic CH 4 oxidation was mainly controlled by the dissolved O 2 concentration, while in the summer it was controlled primarily by the CH 4 concentration, which was scarce compared to dissolved O 2. The permafrost environment of the lakes was identified as another key factor. Thermokarst (thaw) lakes formed in yedoma-type permafrost had significantly higher CH 4 oxidation rates compared to other thermokarst and non-thermokarst lakes formed in non-yedoma permafrost environments. As thermokarst lakes formed in yedoma-type permafrost have been identified to receive large quantities of terrestrial organic carbon from thaw and subsidence of the surrounding landscape into the lake, confirming the strong coupling between terrestrial and aquatic habitats and its influence on CH 4 cycling.« less

Methane gas generation from waste water extraction process of crude palm oil in experimental digesters

NASA Astrophysics Data System (ADS)

Dillon, A.; Penafiel, R.; Garzón, P. V.; Ochoa, V.

2015-12-01

Industrial processes to extract crude palm oil, generates large amounts of waste water. High concentrations of COD, ST, SV, NH4 + and low solubility of O2, make the treatment of these effluents starts with anaerobic processes. The anaerobic digestion process has several advantages over aerobic degradation: lower operating costs (not aeration), low sludge production, methane gas generation. The 4 stages of anaerobic digestion are: hydrolysis, acidogenic, acetogenesis and methanogenesis. Through the action of enzymes synthesized by microbial consortia are met. The products of each step to serve as reagents is conducted as follows. The organic load times and cell hydraulic retention, solids content, nutrient availability, pH and temperature are factors that influence directly in biodigesters. The objectives of this presentation is to; characterize the microbial inoculum and water (from palm oil wasted water) to be used in biodigestores, make specific methanogenic activity in bioassays, acclimatize the microorganisms to produce methane gas using basal mineral medium with acetate for the input power, and to determine the production of methane gas digesters high organic load.

C3N4-H5PMo10V2O40: a dual-catalysis system for reductant-free aerobic oxidation of benzene to phenol

NASA Astrophysics Data System (ADS)

Long, Zhouyang; Zhou, Yu; Chen, Guojian; Ge, Weilin; Wang, Jun

2014-01-01

Hydroxylation of benzene is a widely studied atom economical and environmental benign reaction for producing phenol, aiming to replace the existing three-step cumene process. Aerobic oxidation of benzene with O2 is an ideal and dream process, but benzene and O2 are so inert that current systems either require expensive noble metal catalysts or wasteful sacrificial reducing agents; otherwise, phenol yields are extremely low. Here we report a dual-catalysis non-noble metal system by simultaneously using graphitic carbon nitride (C3N4) and Keggin-type polyoxometalate H5PMo10V2O40 (PMoV2) as catalysts, showing an exceptional activity for reductant-free aerobic oxidation of benzene to phenol. The dual-catalysis mechanism results in an unusual route to create phenol, in which benzene is activated on the melem unit of C3N4 and O2 by the V-O-V structure of PMoV2. This system is simple, highly efficient and thus may lead the one-step production of phenol from benzene to a more practical pathway.

C3N4-H5PMo10V2O40: a dual-catalysis system for reductant-free aerobic oxidation of benzene to phenol

PubMed Central

Long, Zhouyang; Zhou, Yu; Chen, Guojian; Ge, Weilin; Wang, Jun

2014-01-01

Hydroxylation of benzene is a widely studied atom economical and environmental benign reaction for producing phenol, aiming to replace the existing three-step cumene process. Aerobic oxidation of benzene with O2 is an ideal and dream process, but benzene and O2 are so inert that current systems either require expensive noble metal catalysts or wasteful sacrificial reducing agents; otherwise, phenol yields are extremely low. Here we report a dual-catalysis non-noble metal system by simultaneously using graphitic carbon nitride (C3N4) and Keggin-type polyoxometalate H5PMo10V2O40 (PMoV2) as catalysts, showing an exceptional activity for reductant-free aerobic oxidation of benzene to phenol. The dual-catalysis mechanism results in an unusual route to create phenol, in which benzene is activated on the melem unit of C3N4 and O2 by the V-O-V structure of PMoV2. This system is simple, highly efficient and thus may lead the one-step production of phenol from benzene to a more practical pathway. PMID:24413448

Aerobic Biodegradation Characteristic of Different Water-Soluble Azo Dyes

PubMed Central

Sheng, Shixiong; Liu, Bo; Hou, Xiangyu; Wu, Bing; Yao, Fang; Ding, Xinchun; Huang, Lin

2017-01-01

This study investigated the biodegradation performance and characteristics of Sudan I and Acid Orange 7 (AO7) to improve the biological dye removal efficiency in wastewater and optimize the treatment process. The dyes with different water-solubility and similar molecular structure were biologically treated under aerobic condition in parallel continuous-flow mixed stirred reactors. The biophase analysis using microscopic examination suggested that the removal process of the two azo dyes is different. Removal of Sudan I was through biosorption, since it easily assembled and adsorbed on the surface of zoogloea due to its insolubility, while AO7 was biodegraded incompletely and bioconverted, the AO7 molecule was decomposed to benzene series and inorganic ions, since it could reach the interior area of zoogloea due to the low oxidation-reduction potential conditions and corresponding anaerobic microorganisms. The transformation of NH3-N, SO42− together with the presence of tryptophan-like components confirm that AO7 can be decomposed to non-toxic products in an aerobic bioreactor. This study provides a theoretical basis for the use of biosorption or biodegradation mechanisms for the treatment of different azo dyes in wastewater. PMID:29278390

Microbiology and potential applications of aerobic methane oxidation coupled to denitrification (AME-D) process: A review.

PubMed

Zhu, Jing; Wang, Qian; Yuan, Mengdong; Tan, Giin-Yu Amy; Sun, Faqian; Wang, Cheng; Wu, Weixiang; Lee, Po-Heng

2016-03-01

Aerobic methane oxidation coupled to denitrification (AME-D) is an important link between the global methane and nitrogen cycles. This mini-review updates discoveries regarding aerobic methanotrophs and denitrifiers, as a prelude to spotlight the microbial mechanism and the potential applications of AME-D. Until recently, AME-D was thought to be accomplished by a microbial consortium where denitrifying bacteria utilize carbon intermediates, which are excreted by aerobic methanotrophs, as energy and carbon sources. Potential carbon intermediates include methanol, citrate and acetate. This mini-review presents microbial thermodynamic estimations and postulates that methanol is the ideal electron donor for denitrification, and may serve as a trophic link between methanotrophic bacteria and denitrifiers. More excitingly, new discoveries have revealed that AME-D is not only confined to the conventional synergism between methanotrophic bacteria and denitrifiers. Specifically, an obligate aerobic methanotrophic bacterium, Methylomonas denitrificans FJG1, has been demonstrated to couple partial denitrification with methane oxidation, under hypoxia conditions, releasing nitrous oxide as a terminal product. This finding not only substantially advances the understanding of AME-D mechanism, but also implies an important but unknown role of aerobic methanotrophs in global climate change through their influence on both the methane and nitrogen cycles in ecosystems. Hence, further investigation on AME-D microbiology and mechanism is essential to better understand global climate issues and to develop niche biotechnological solutions. This mini-review also presents traditional microbial techniques, such as pure cultivation and stable isotope probing, and powerful microbial techniques, such as (meta-) genomics and (meta-) transcriptomics, for deciphering linked methane oxidation and denitrification. Although AME-D has immense potential for nitrogen removal from wastewater, drinking water and groundwater, bottlenecks and potential issues are also discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Separation of swine wastewater into different concentration fractions and its contribution to combined anaerobic-aerobic process.

PubMed

Yang, Di; Deng, Liangwei; Zheng, Dan; Wang, Lan; Liu, Yi

2016-03-01

There are two problems associated with treatment of swine wastewater, low efficiency of anaerobic digestion during winter and poor performance for aerobic treatment of digested effluent. A strategy employing unbalanced distributions of the pollutant mass and wastewater volumes in anaerobic and aerobic units was proposed. To accomplish this, swine wastewater was separated into high content liquid (HCL) and low content liquid (LCL). Three separation ratios of HCL to LCL (v/v), 1:9 (S1), 2:8 (S2), and 3:7 (S3), were evaluated. Anaerobically digestion of the HCL accounted for only 10%, 20% and 30% of the total volume of raw wastewater, but produced 63.38%, 73.79% and 76.61% of the total methane output for S1, S2 and S3, respectively. The mixed liquid of digested effluents of HCL and LCL were treated aerobically using sequencing batch reactors. S2 generated the best performance, with removal efficiencies of 96.98% for COD, 98.95% for NH3-N, 91.69% for TN and 74.71% for TP. The results obtained for S1 were not as good as those for S2, but were better than those for S3. Based on methane output from the anaerobic unit and pollutants removal in the aerobic unit, S2 was the most suitable system for the treatment of swine wastewater. Additionally, the anaerobic digestion efficiency of S2 was 282% higher than that of previous techniques employing balanced distribution. Taken together, these findings indicate that unbalanced distribution could improve the efficiency of the anaerobic unit remarkably, while ensuring good performance of the aerobic unit. Copyright © 2015. Published by Elsevier Ltd.

A comparison of aerobic granular sludge with conventional and compact biological treatment technologies.

PubMed

Bengtsson, Simon; de Blois, Mark; Wilén, Britt-Marie; Gustavsson, David

2018-03-20

The aerobic granular sludge (AGS) technology is growing towards becoming a mature option for new municipal wastewater treatment plants and capacity extensions. A process based on AGS was compared to conventional activated sludge processes (with and without enhanced biological phosphorus removal), an integrated fixed-film activated sludge (IFAS) process and a membrane bioreactor (MBR) by estimating the land area demand (footprint), electricity demand and chemicals' consumption. The process alternatives compared included pre-settling, sludge digestion and necessary post-treatment to achieve effluent concentrations of 8 mg/L nitrogen and 0.2 mg/L phosphorus at 7°C. The alternative based on AGS was estimated to have a 40-50% smaller footprint and 23% less electricity requirement than conventional activated sludge. In relation to the other compact treatment options IFAS and MBR, the AGS process had an estimated electricity usage that was 35-70% lower. This suggests a favourable potential for processes based on AGS although more available experience of AGS operation and performance at full scale is desired.

Comparative analysis of sugarcane bagasse metagenome reveals unique and conserved biomass-degrading enzymes among lignocellulolytic microbial communities.

PubMed

Mhuantong, Wuttichai; Charoensawan, Varodom; Kanokratana, Pattanop; Tangphatsornruang, Sithichoke; Champreda, Verawat

2015-01-01

As one of the most abundant agricultural wastes, sugarcane bagasse is largely under-exploited, but it possesses a great potential for the biofuel, fermentation, and cellulosic biorefinery industries. It also provides a unique ecological niche, as the microbes in this lignocellulose-rich environment thrive in relatively high temperatures (50°C) with varying microenvironments of aerobic surface to anoxic interior. The microbial community in bagasse thus presents a good resource for the discovery and characterization of new biomass-degrading enzymes; however, it remains largely unexplored. We have constructed a fosmid library of sugarcane bagasse and obtained the largest bagasse metagenome to date. A taxonomic classification of the bagasse metagenome reviews the predominance of Proteobacteria, which are also found in high abundance in other aerobic environments. Based on the functional characterization of biomass-degrading enzymes, we have demonstrated that the bagasse microbial community benefits from a large repertoire of lignocellulolytic enzymes, which allows them to digest different components of lignocelluoses into single molecule sugars. Comparative genomic analyses with other lignocellulolytic and non-lignocellulolytic metagenomes show that microbial communities are taxonomically separable by their aerobic "open" or anoxic "closed" environments. Importantly, a functional analysis of lignocellulose-active genes (based on the CAZy classifications) reveals core enzymes highly conserved within the lignocellulolytic group, regardless of their taxonomic compositions. Cellulases, in particular, are markedly more pronounced compared to the non-lignocellulolytic group. In addition to the core enzymes, the bagasse fosmid library also contains some uniquely enriched glycoside hydrolases, as well as a large repertoire of the newly defined auxiliary activity proteins. Our study demonstrates a conservation and diversification of carbohydrate-active genes among diverse microbial species in different biomass-degrading niches, and signifies the importance of taking a global approach to functionally investigate a microbial community as a whole, as compared to focusing on individual organisms.

The Integration of Internal and External Training Load Metrics in Hurling

PubMed Central

Doran, Dominic; Akubat, Ibrahim; Collins, Kieran

2016-01-01

Abstract The current study aimed to assess the relationship between the hurling player’s fitness profile and integrated training load (TL) metrics. Twenty-five hurling players performed treadmill testing for VO2max, the speed at blood lactate concentrations of 2 mmol•L-1 (vLT) and 4 mmol•L-1 (vOBLA) and the heart rate-blood lactate profile for calculation of individual training impulse (iTRIMP). The total distance (TD; m), high speed distance (HSD; m) and sprint distance (SD; m) covered were measured using GPS technology (4-Hz, VX Sport, Lower Hutt, New Zealand) which allowed for the measurement of the external TL. The external TL was divided by the internal TL to form integration ratios. Pearson correlation analyses allowed for the assessment of the relationships between fitness measures and the ratios to performance during simulated match play. External measures of the TL alone showed limited correlations with fitness measures. Integrated TL ratios showed significant relationships with fitness measures in players. TD:iTRIMP was correlated with aerobic fitness measures VO2max (r = 0.524; p = 0.006; 95% CI: 0.224 to 0.754; large) and vOBLA (r = 0.559; p = 0.003; 95% CI: 0.254 to 0.854; large). HSD:iTRIMP also correlated with aerobic markers for fitness vLT (r = 0.502; p = 0.009; 95% CI: 0.204 to 0.801; large); vOBLA (r = 0.407; p = 0.039; 95% CI: 0.024 to 0.644; moderate). Interestingly SD:iTRIMP also showed significant correlations with vLT (r = 0.611; p = 0.001; 95% CI: 0.324 to 0.754; large). The current study showed that TL ratios can provide practitioners with a measure of fitness as external performance alone showed limited relationships with aerobic fitness measures. PMID:28149425

A modeling understanding on the phosphorous removal performances of A2O and reversed A2O processes in a full-scale wastewater treatment plant.

PubMed

Xie, Wen-Ming; Zeng, Raymond J; Li, Wen-Wei; Wang, Guo-Xiang; Zhang, Li-Min

2018-05-31

Reversed A 2 O process (anoxic-anaerobic-aerobic) and conventional A 2 O process (anaerobic-anoxic-aerobic) are widely used in many wastewater treatment plants (WWTPs) in Asia. However, at present, there are still no consistent results to figure out which process has better total phosphorous (TP) removal performance and the mechanism for this difference was not clear yet. In this study, the treatment performances of both processes were compared in the same full-scale WWTP and the TP removal dynamics was analyzed by a modeling method. The treatment performance of full-scale WWTP showed the TP removal efficiency of the reversed A 2 O process was more efficient than in the conventional A 2 O process. The modeling results further reveal that the TP removal depends highly on the concentration and composition of influent COD. It had more efficient TP removal than the conventional A 2 O process only under conditions of sufficient influent COD and high fermentation products content. This study may lay a foundation for appropriate selection and optimization of treatment processes to suit practical wastewater properties.

Continuous Flow Aerobic Alcohol Oxidation Reactions Using a Heterogeneous Ru(OH)x/Al2O3 Catalyst

PubMed Central

2015-01-01

Ru(OH)x/Al2O3 is among the more versatile catalysts for aerobic alcohol oxidation and dehydrogenation of nitrogen heterocycles. Here, we describe the translation of batch reactions to a continuous-flow method that enables high steady-state conversion and single-pass yields in the oxidation of benzylic alcohols and dehydrogenation of indoline. A dilute source of O2 (8% in N2) was used to ensure that the reaction mixture, which employs toluene as the solvent, is nonflammable throughout the process. A packed bed reactor was operated isothermally in an up-flow orientation, allowing good liquid–solid contact. Deactivation of the catalyst during the reaction was modeled empirically, and this model was used to achieve high conversion and yield during extended operation in the aerobic oxidation of 2-thiophene methanol (99+% continuous yield over 72 h). PMID:25620869

Issues for storing plant-based alternative fuels in marine environments.

PubMed

Lee, Jason S; Ray, Richard I; Little, Brenda J; Duncan, Kathleen E; Aktas, Deniz F; Oldham, Athenia L; Davidova, Irene A; Suflita, Joseph M

2014-06-01

Two coastal seawaters (Key West, FL, USA and the Persian Gulf, Bahrain, representing oligotrophic and eutrophic environments, respectively) were used to evaluate potential biodegradation and corrosion problems during exposure to alternative and conventional fuels. Uncoated carbon steel was exposed at the fuel/seawater interface and polarization resistance was monitored. Under typical marine storage conditions, dioxygen in natural seawater exposed to fuel and carbon steel was reduced to <0.1parts-per-million within 2d due to consumption by corrosion reactions and aerobic microbial respiration. Sulfides, produced by anaerobic sulfate-reducing bacteria, and chlorides were co-located in corrosion products. Transient dioxygen influenced both metabolic degradation pathways and resulting metabolites. Catechols, indicative of aerobic biodegradation, persisted after 90d exposures. Detection of catechols suggested that initial exposure to dioxygen resulted in the formation of aerobic metabolites that exacerbated subsequent corrosion processes. Published by Elsevier B.V.

A bioinspired catalytic aerobic oxidative C-H functionalization of primary aliphatic amines: synthesis of 1,2-disubstituted benzimidazoles.

PubMed

Nguyen, Khac Minh Huy; Largeron, Martine

2015-09-01

Aerobic oxidative CH functionalization of primary aliphatic amines has been accomplished with a biomimetic cooperative catalytic system to furnish 1,2-disubstituted benzimidazoles that play an important role as drug discovery targets. This one-pot atom-economical multistep process, which proceeds under mild conditions, with ambient air and equimolar amounts of each coupling partner, constitutes a convenient environmentally friendly strategy to functionalize non-activated aliphatic amines that remain challenging substrates for non-enzymatic catalytic aerobic systems. © 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of Creative Commons Attribution NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Arsenic redox transformation by Pseudomonas sp. HN-2 isolated from arsenic-contaminated soil in Hunan, China.

PubMed

Zhang, Zhennan; Yin, Naiyi; Cai, Xiaolin; Wang, Zhenzhou; Cui, Yanshan

2016-09-01

A mesophilic, Gram-negative, arsenite[As(III)]-oxidizing and arsenate[As(V)]-reducing bacterial strain, Pseudomonas sp. HN-2, was isolated from an As-contaminated soil. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the strain was closely related to Pseudomonas stutzeri. Under aerobic conditions, this strain oxidized 92.0% (61.4μmol/L) of arsenite to arsenate within 3hr of incubation. Reduction of As(V) to As(III) occurred in anoxic conditions. Pseudomonas sp. HN-2 is among the first soil bacteria shown to be capable of both aerobic As(III) oxidation and anoxic As(V) reduction. The strain, as an efficient As(III) oxidizer and As(V) reducer in Pseudomonas, has the potential to impact arsenic mobility in both anoxic and aerobic environments, and has potential application in As remediation processes. Copyright © 2016. Published by Elsevier B.V.

Variation in microbial activity in histosols and its relationship to soil moisture.

PubMed

Tate, R L; Terry, R E

1980-08-01

Microbial biomass, dehydrogenase activity, carbon metabolism, and aerobic bacterial populations were examined in cropped and fallow Pahokee muck (a lithic medisaprist) of the Florida Everglades. Dehydrogenase activity was two- to sevenfold greater in soil cropped to St. Augustinegrass (Stenotaphrum secundatum (Walt) Kuntz) compared with uncropped soil, whereas biomass ranged from equivalence in the two soils to a threefold stimulation in the cropped soil. Biomass in soil cropped to sugarcane (Saccharum spp. L) approximated that from the grass field, whereas dehydrogenase activities of the cane soil were nearly equivalent to those of the fallow soil. Microbial biomass, dehydrogenase activity, aerobic bacterial populations, and salicylate oxidation rates all correlated with soil moisture levels. These data indicate that within the moisture ranges detected in the surface soils, increased moisture stimulated microbial activity, whereas within the soil profile where moisture ranges reached saturation, increased moisture inhibited aerobic activities and stimulated anaerobic processes.

Variation in Microbial Activity in Histosols and Its Relationship to Soil Moisture †

PubMed Central

Tate, Robert L.; Terry, Richard E.

1980-01-01

Microbial biomass, dehydrogenase activity, carbon metabolism, and aerobic bacterial populations were examined in cropped and fallow Pahokee muck (a lithic medisaprist) of the Florida Everglades. Dehydrogenase activity was two- to sevenfold greater in soil cropped to St. Augustinegrass (Stenotaphrum secundatum (Walt) Kuntz) compared with uncropped soil, whereas biomass ranged from equivalence in the two soils to a threefold stimulation in the cropped soil. Biomass in soil cropped to sugarcane (Saccharum spp. L) approximated that from the grass field, whereas dehydrogenase activities of the cane soil were nearly equivalent to those of the fallow soil. Microbial biomass, dehydrogenase activity, aerobic bacterial populations, and salicylate oxidation rates all correlated with soil moisture levels. These data indicate that within the moisture ranges detected in the surface soils, increased moisture stimulated microbial activity, whereas within the soil profile where moisture ranges reached saturation, increased moisture inhibited aerobic activities and stimulated anaerobic processes. PMID:16345610

Effects of Physical Activity on Children’s Executive Function: Contributions of Experimental Research on Aerobic Exercise

PubMed Central

Best, John R.

2011-01-01

Executive function refers to the cognitive processes necessary for goal-directed cognition and behavior, which develop across childhood and adolescence. Recent experimental research indicates that both acute and chronic aerobic exercise promote children’s executive function. Furthermore, there is tentative evidence that not all forms of aerobic exercise benefit executive function equally: Cognitively-engaging exercise appears to have a stronger effect than non-engaging exercise on children’s executive function. This review discusses this evidence as well as the mechanisms that may underlie the association between exercise and executive function. Research from a variety of disciplines is covered, including developmental psychology, kinesiology, cognitive neuroscience, and biopsychology. Finally, these experimental findings are placed within the larger context of known links between action and cognition in infancy and early childhood, and the clinical and practical implications of this research are discussed. PMID:21818169

Aerobic and heterotrophic nitrogen removal by Enterobacter cloacae CF-S27 with efficient utilization of hydroxylamine.

PubMed

Padhi, Soumesh Kumar; Tripathy, Swetaleena; Mohanty, Sriprakash; Maiti, Nikhil Kumar

2017-05-01

Heterotrophic bacterium, Enterobacter cloacae CF-S27 exhibited simultaneous nitrification and aerobic denitrification in presence of high concentration of hydroxylamine. With the initial nitrogen concentration of 100mgL -1 h -1 , ammonium, nitrate and nitrite removal efficiencies were 81%, 99.9% and 92.8%, while the corresponding maximum removal rates reached as high as 11.6, 15.1 and 11.2mgL -1 h -1 respectively. Quantitative amplification by real time PCR and enzyme assay demonstrated that hydroxylamine reductase gene (hao) is actively involved in hetrotrophic nitrification and aerobic denitrification process of Enterobacter cloacae CF-S27. PCR primers were designed targeting amplification of hao gene from diversified environmental soil DNA. The strain Enterobacter cloacae CF-S27 significantly maintained the undetectable amount of dissolved nitrogen throughout 60days of zero water exchange fish culture experiment in domestic wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of temperature on solids reductions and on degradation kinetics during thermophilic aerobic digestion of a simulated sludge.

PubMed

Toki, C J

2008-07-01

Laboratory-scale experiments were conducted to determine the influence of higher thermophilic temperatures on thermophilic aerobic digestion treatment of a simulated sludge. The efficiency of the process was evaluated in respect of solids removal and degradation rate constants at four thermophilic temperatures. Batch runs were operated at a retention time of one day and temperatures of 65, 70, 72 and 75 degrees C. The results indicated that temperature increase did not impart any significant benefits to the digestion operation in terms of suspended solids and biochemichal oxygen demand reduction. The findings from this research also suggested that the treatment would not appear to benefit from temperatures higher than 65 degrees C, as classically suggested by Van't Hoff-Arrhenius. Therefore, increase of thermophilic temperature in the tested 65-75 degrees C range does not enhance the efficiency of thermophilic, aerobic sludge digestion treatment.

A microbiological surrogate for evaluating treatment efficiency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rice, E.W.; Fox, K.W.; Miltner, R.J.

1995-10-01

In this study we report on the use of a microbial surrogate system which can be used to evaluate the efficiency of various unit processes used in drinking water treatment for the removal of microbial contaminants. The proposed procedure uses Gram-positive, mesophilic, aerobic spore-forming bacteria as the surrogate organisms. These bacteria do not pose a public health threat and are naturally occurring in most surface water supplies. The aerobic spore-formers are easy to culture and are present throughout the treatment train. This group of organisms consists primarily of species of the genus Bacillus. These organisms form endospores which are ellipsoidalmore » to spherical in shape and measure on average approximately 0.5 X 1.0 X 1.5 micrometers, and are environmentally resistant. Like pathogenic Giardia cysts and Cryptosporidium oocysts endospores of aerobic bacilli may be found far into the treatment train.« less

Neuronal control of astrocytic respiration through a variant of the Crabtree effect.

PubMed

Fernández-Moncada, Ignacio; Ruminot, Iván; Robles-Maldonado, Daniel; Alegría, Karin; Deitmer, Joachim W; Barros, L Felipe

2018-02-13

Aerobic glycolysis is a phenomenon that in the long term contributes to synaptic formation and growth, is reduced by normal aging, and correlates with amyloid beta deposition. Aerobic glycolysis starts within seconds of neural activity and it is not obvious why energetic efficiency should be compromised precisely when energy demand is highest. Using genetically encoded FRET nanosensors and real-time oxygen measurements in culture and in hippocampal slices, we show here that astrocytes respond to physiological extracellular K + with an acute rise in cytosolic ATP and a parallel inhibition of oxygen consumption, explained by glycolytic stimulation via the Na + -bicarbonate cotransporter NBCe1. This control of mitochondrial respiration via glycolysis modulation is reminiscent of a phenomenon previously described in proliferating cells, known as the Crabtree effect. Fast brain aerobic glycolysis may be interpreted as a strategy whereby neurons manipulate neighboring astrocytes to obtain oxygen, thus maximizing information processing.

Monitoring pH and electric conductivity in an EBPR sequencing batch reactor.

PubMed

Serralta, J; Borrás, L; Blanco, C; Barat, R; Seco, A

2004-01-01

This paper presents laboratory-scale experimentation carried out to study enhanced biological phosphorus removal. Two anaerobic aerobic (A/O) sequencing batch reactors (SBR) have been operated during more than one year to investigate the information provided by monitoring pH and electric conductivity under stationary and transient conditions. Continuous measurements of these parameters allow detecting the end of anaerobic phosphorus release, of aerobic phosphorus uptake and of initial denitrification, as well as incomplete acetic acid uptake. These results suggest the possibility of using pH and electric conductivity as control parameters to determine the length of both anaerobic and aerobic phases in an A/O SBR. More valuable information provided by monitoring pH and electric conductivity is the relation between the amount of phosphorus released and the conductivity increase observed during the anaerobic stages and which group of bacteria (heterotrophic or polyphosphate accumulating) is carrying out the denitrification process.

Copper (II) adsorption by the extracellular polymeric substance extracted from waste activated sludge after short-time aerobic digestion.

PubMed

Zhang, Zhiqiang; Zhou, Yun; Zhang, Jiao; Xia, Siqing

2014-02-01

The extracellular polymeric substance (EPS) extracted from waste activated sludge (WAS) after short-time aerobic digestion was investigated to be used as a novel biosorbent for Cu(2+) removal from water. The EPS consisted of protein (52.6 %, w/w), polysaccharide (30.7 %, w/w), and nucleic acid (16.7 %, w/w). Short-time aerobic digestion process of WAS for about 4 h promoted the productivity growth of the EPS for about 10 %. With a molecular weight of about 1.9 × 10(6) Da, the EPS showed a linear structure with long chains, and contained carboxyl, hydroxyl, and amino groups. The sorption kinetics was well fit for the pseudo-second-order model, and the maximum sorption capacity of the EPS (700.3 mg Cu(2+)/g EPS) was markedly greater than those of the reported biosorbents. Both Langmuir model and Freundlich model commendably described the sorption isotherm. The Gibbs free energy analysis of the adsorption showed that the sorption process was feasible and spontaneous. According to the complex results of multiple analytical techniques, including scanning electron microscopy, Fourier transform infrared spectroscopy, atomic force microscopy, etc., the adsorption process took place via both physical and chemical sorption, but the electrostatic interaction between sorption sites with the functional groups and Cu(2+) is the major mechanism.

Biofilms associated with poultry processing equipment.

PubMed

Lindsay, D; Geornaras, I; von Holy, A

1996-01-01

Aerobic and Gram-negative bacteria were enumerated on non-metallic surfaces and stainless steel test pieces attached to equipment surfaces by swabbing and a mechanical dislodging procedure, respectively, in a South African grade B poultry processing plant. Changes in bacterial numbers were also monitored over time on metal test pieces. The highest bacterial counts were obtained from non-metallic surfaces such as rubber fingered pluckers and plastic defeathering curtains which exceeded the highest counts found on the metal surfaces by at least 1 log CFU cm-2. Gram-negative bacterial counts on all non-metallic surface types were at least 2 log CFU cm-2 lower than corresponding aerobic plate counts. On metal surfaces, the highest microbial numbers were obtained after 14 days exposure, with aerobic plate counts ranging from 3.57 log CFU cm-2 to 5.13 log CFU cm-2, and Gram-negative counts from 0.70 log CFU cm-2 to 3.31 log CFU cm-2. Scanning electron microscopy confirmed the presence of bacterial cells on non-metallic and metallic surfaces associated with poultry processing. Rubber 'fingers', plastic curtains, conveyor belt material and stainless steel test surfaces placed on the scald tank overflow and several chutes revealed extensive and often confluent bacterial biofilms. Extracellular polymeric substances, but few bacterial cells were visible on test pieces placed on evisceration equipment, spinchiller blades and the spinchiller outlet.

Microbiological survey of a South African poultry processing plant.

PubMed

Geornaras, I; de Jesus, A; van Zyl, E; von Holy, A

1995-01-01

Bacterial populations associated with poultry processing were determined on neck skin samples, equipment surfaces and environmental samples by replicate surveys. Aerobic plate counts, Enterobacteriaceae counts, Enterobacteriaceae counts and Pseudomonas counts were performed by standard procedures and the prevalence of Listeria, presumptive Salmonella and Staphylococcus aureus determined. Statistically significant (P < 0.05) increases in counts of all types of bacteria were obtained on product samples as a result of processing. Although bacterial counts on neck skin samples decreased by 0.3 to 0.4 log CFU g-1 after spray washing of carcasses, subsequent spinchilling and packaging of whole carcasses resulted in 0.7 to 1.2 log CFU g-1 increases. Bacterial numbers on equipment surfaces, however, decreased significantly from the "dirty" to the "clean" areas of the abattoir. Transport cages, "rubber fingers", defeathering curtains, shackles and conveyor belts repeatedly showed aerobic plate counts in excess of 5.0 log CFU 25 cm-2. Aerobic plate counts of scald tank and spinchiller water were 2 log CFU ml-1 higher than those of potable water samples. Bacterial numbers of the air in the "dirty" area were higher than those of the "clean" area. Listeria, presumptive Salmonella and Staphylococcus aureus were isolated from 27.6, 51.7 and 24.1% of all product samples, respectively, and Listeria and Staphylococcus aureus were also isolated from selected equipment surfaces.

Sorption and Release of Organics by Primary, Anaerobic, and Aerobic Activated Sludge Mixed with Raw Municipal Wastewater

PubMed Central

Modin, Oskar; Saheb Alam, Soroush; Persson, Frank; Wilén, Britt-Marie

2015-01-01

New activated sludge processes that utilize sorption as a major mechanism for organics removal are being developed to maximize energy recovery from wastewater organics, or as enhanced primary treatment technologies. To model and optimize sorption-based activated sludge processes, further knowledge about sorption of organics onto sludge is needed. This study compared primary-, anaerobic-, and aerobic activated sludge as sorbents, determined sorption capacity and kinetics, and investigated some characteristics of the organics being sorbed. Batch sorption assays were carried out without aeration at a mixing velocity of 200 rpm. Only aerobic activated sludge showed net sorption of organics. Sorption of dissolved organics occurred by a near-instantaneous sorption event followed by a slower process that obeyed 1st order kinetics. Sorption of particulates also followed 1st order kinetics but there was no instantaneous sorption event; instead there was a release of particles upon mixing. The 5-min sorption capacity of activated sludge was 6.5±10.8 mg total organic carbon (TOC) per g volatile suspend solids (VSS) for particulate organics and 5.0±4.7 mgTOC/gVSS for dissolved organics. The observed instantaneous sorption appeared to be mainly due to organics larger than 20 kDa in size being sorbed, although molecules with a size of about 200 Da with strong UV absorbance at 215–230 nm were also rapidly removed. PMID:25768429

Electricity generation from tetrathionate in microbial fuel cells by acidophiles.

PubMed

Sulonen, Mira L K; Kokko, Marika E; Lakaniemi, Aino-Maija; Puhakka, Jaakko A

2015-03-02

Inorganic sulfur compounds, such as tetrathionate, are often present in mining process and waste waters. The biodegradation of tetrathionate was studied under acidic conditions in aerobic batch cultivations and in anaerobic anodes of two-chamber flow-through microbial fuel cells (MFCs). All four cultures originating from biohydrometallurgical process waters from multimetal ore heap bioleaching oxidized tetrathionate aerobically at pH below 3 with sulfate as the main soluble metabolite. In addition, all cultures generated electricity from tetrathionate in MFCs at pH below 2.5 with ferric iron as the terminal cathodic electron acceptor. The maximum current and power densities during MFC operation and in the performance analysis were 79.6 mA m(-2) and 13.9 mW m(-2) and 433 mA m(-2) and 17.6 mW m(-2), respectively. However, the low coulombic efficiency (below 5%) indicates that most of the electrons were directed to other processes, such as aerobic oxidation of tetrathionate and unmeasured intermediates. The microbial community analysis revealed that the dominant species both in the anolyte and on the anode electrode surface of the MFCs were Acidithiobacillus spp. and Ferroplasma spp. This study provides a proof of concept that tetrathionate serves as electron donor for biological electricity production in the pH range of 1.2-2.5. Copyright © 2014 Elsevier B.V. All rights reserved.

Potential carbon emissions dominated by carbon dioxide from thawed permafrost soils

DOE PAGES

Schadel, Christina; Bader, Martin K. F.; Schuur, Edward; ...

2016-01-01

Increasing temperatures in northern high latitudes are causing permafrost to thaw, making large amounts of previously frozen organic matter vulnerable to microbial decomposition. Permafrost thaw also creates a fragmented landscape of drier and wetter soil conditions that determine the amount and form (carbon dioxide (CO2), or methane (CH4)) of carbon (C) released to the atmosphere. The rate and form of C release control the magnitude of the permafrost C feedback, so their relative contribution with a warming climate remains unclear. We quantified the effect of increasing temperature and changes from aerobic to anaerobic soil conditions using 25 soil incubation studiesmore » from the permafrost zone. Here we show, using two separate meta-analyses, that a 10 C increase in incubation temperature increased C release by a factor of 2.0 (95% confidence interval (CI), 1.8 to 2.2). Under aerobic incubation conditions, soils released 3.4 (95% CI, 2.2 to 5.2) times more C than under anaerobic conditions. Even when accounting for the higher heat trapping capacity of CH4, soils released 2.3 (95% CI, 1.5 to 3.4) times more C under aerobic conditions. These results imply that permafrost ecosystems thawing under aerobic conditions and releasing CO2 will strengthen the permafrost C feedback more than waterlogged systemsreleasingCO2 andCH4 for a given amount of C.« less

Potential carbon emissions dominated by carbon dioxide from thawed permafrost soils

USGS Publications Warehouse

Schädel, Christina; Bader, Martin K.-F.; Schuur, Edward A.G.; Biasi, Christina; Bracho, Rosvel; Čapek, Petr; De Baets, Sarah; Diáková, Kateřina; Ernakovich, Jessica; Estop-Aragones, Cristian; Graham, David E.; Hartley, Iain P.; Iversen, Colleen M.; Kane, Evan S.; Knoblauch, Christian; Lupascu, Massimo; Martikainen, Pertti J.; Natali, Susan M.; Norby, Richard J.; O'Donnell, Jonathan A.; Roy Chowdhury, Taniya; Šantrůčková, Hana; Shaver, Gaius; Sloan, Victoria L.; Treat, Claire C.; Turetsky, Merritt R.; Waldrop, Mark P.; Wickland, Kimberly P.

2016-01-01

Increasing temperatures in northern high latitudes are causing permafrost to thaw, making large amounts of previously frozen organic matter vulnerable to microbial decomposition. Permafrost thaw also creates a fragmented landscape of drier and wetter soil conditions that determine the amount and form (carbon dioxide (CO2), or methane (CH4)) of carbon (C) released to the atmosphere. The rate and form of C release control the magnitude of the permafrost C feedback, so their relative contribution with a warming climate remains unclear. We quantified the effect of increasing temperature and changes from aerobic to anaerobic soil conditions using 25 soil incubation studies from the permafrost zone. Here we show, using two separate meta-analyses, that a 10 °C increase in incubation temperature increased C release by a factor of 2.0 (95% confidence interval (CI), 1.8 to 2.2). Under aerobic incubation conditions, soils released 3.4 (95% CI, 2.2 to 5.2) times more C than under anaerobic conditions. Even when accounting for the higher heat trapping capacity of CH4, soils released 2.3 (95% CI, 1.5 to 3.4) times more C under aerobic conditions. These results imply that permafrost ecosystems thawing under aerobic conditions and releasing CO2 will strengthen the permafrost C feedback more than waterlogged systems releasing CO2 and CH4 for a given amount of C.

Aerobic fitness and physical activity levels of children born prematurely following randomization to postnatal dexamethasone.

PubMed

Nixon, Patricia A; Washburn, Lisa K; Mudd, Lanay M; Webb, Heather H; O'Shea, T Michael

2011-01-01

To investigate the effects of postnatal dexamethasone treatment on aerobic fitness and physical activity levels in school-aged children born with very low birth weight (VLBW). This was a follow-up study of 65 VLBW infants who participated in a randomized controlled trial of dexamethasone (DEX) to reduce ventilator dependency. Aerobic fitness was determined from peak oxygen uptake (VO(2peak)) with a cycle ergometer. Habitual physical activity was assessed by questionnaire. A trend for a treatment with an interaction between treatment and of diagnosis of chronic lung disease (CLD) was found, with the children in the placebo group with CLD having the lowest VO(2peak) (P = .09). Reduced fitness was seen in 53% of the group treated with DEX and 48% of the group given placebo. No between-group differences in physical activity were seen. Parental reports suggested that nearly two-thirds of the children participated in < 1 hour per week of vigorous physical activity, which was explained in part by decreased large airway function (r = 0.30; P = .03). We found no adverse effect of postnatal DEX on aerobic fitness or habitual physical activity at school age. However, the reduced fitness and physical activity levels emphasize the need for closer follow-up and early interventions promoting physical activity to reduce the risk of chronic disease in this at-risk population. Copyright © 2011 Mosby, Inc. All rights reserved.

Assessing Commercial and Alternative Poultry Processing Methods using Microbiome Analyses

USDA-ARS?s Scientific Manuscript database

Assessing poultry processing methods/strategies has historically used culture-based methods to assess bacterial changes or reductions, both in terms of general microbial communities (e.g. total aerobic bacteria) or zoonotic pathogens of interest (e.g. Salmonella, Campylobacter). The advent of next ...

Flow-mediated dilation and exercise blood pressure in healthy adolescents

USDA-ARS?s Scientific Manuscript database

Objectives: Atherosclerosis is a process that begins in youth. The endothelium plays an essential role in regulating blood flow and protecting against progression of the initial stages of the atherosclerotic process. Few studies have investigated the relationship between aerobic fitness and exerc...

Metered oxygen supply aids treatment of domestic sewage

NASA Technical Reports Server (NTRS)

Weliky, N.; Hooper, T. J.; Silverman, H. P.

1972-01-01

Microbiological fixed-bed process was developed in which supplementary oxygen required by microbial species is supplied by electrochemical device. Rate of addition of oxygen to waste treatment process is controlled to maintain aerobic metabolism and prevent anaerobic metabolisms which produce odorous or toxic products.

Aerobic Microbial Respiration In Oceanic Oxygen Minimum Zones.

PubMed

Kalvelage, Tim; Lavik, Gaute; Jensen, Marlene M; Revsbech, Niels Peter; Löscher, Carolin; Schunck, Harald; Desai, Dhwani K; Hauss, Helena; Kiko, Rainer; Holtappels, Moritz; LaRoche, Julie; Schmitz, Ruth A; Graco, Michelle I; Kuypers, Marcel M M

2015-01-01

Oxygen minimum zones are major sites of fixed nitrogen loss in the ocean. Recent studies have highlighted the importance of anaerobic ammonium oxidation, anammox, in pelagic nitrogen removal. Sources of ammonium for the anammox reaction, however, remain controversial, as heterotrophic denitrification and alternative anaerobic pathways of organic matter remineralization cannot account for the ammonium requirements of reported anammox rates. Here, we explore the significance of microaerobic respiration as a source of ammonium during organic matter degradation in the oxygen-deficient waters off Namibia and Peru. Experiments with additions of double-labelled oxygen revealed high aerobic activity in the upper OMZs, likely controlled by surface organic matter export. Consistently observed oxygen consumption in samples retrieved throughout the lower OMZs hints at efficient exploitation of vertically and laterally advected, oxygenated waters in this zone by aerobic microorganisms. In accordance, metagenomic and metatranscriptomic analyses identified genes encoding for aerobic terminal oxidases and demonstrated their expression by diverse microbial communities, even in virtually anoxic waters. Our results suggest that microaerobic respiration is a major mode of organic matter remineralization and source of ammonium (~45-100%) in the upper oxygen minimum zones, and reconcile hitherto observed mismatches between ammonium producing and consuming processes therein.

Aerobic Microbial Respiration In Oceanic Oxygen Minimum Zones

PubMed Central

Kalvelage, Tim; Lavik, Gaute; Jensen, Marlene M.; Revsbech, Niels Peter; Löscher, Carolin; Schunck, Harald; Desai, Dhwani K.; Hauss, Helena; Kiko, Rainer; Holtappels, Moritz; LaRoche, Julie; Schmitz, Ruth A.; Graco, Michelle I.; Kuypers, Marcel M. M.

2015-01-01

Oxygen minimum zones are major sites of fixed nitrogen loss in the ocean. Recent studies have highlighted the importance of anaerobic ammonium oxidation, anammox, in pelagic nitrogen removal. Sources of ammonium for the anammox reaction, however, remain controversial, as heterotrophic denitrification and alternative anaerobic pathways of organic matter remineralization cannot account for the ammonium requirements of reported anammox rates. Here, we explore the significance of microaerobic respiration as a source of ammonium during organic matter degradation in the oxygen-deficient waters off Namibia and Peru. Experiments with additions of double-labelled oxygen revealed high aerobic activity in the upper OMZs, likely controlled by surface organic matter export. Consistently observed oxygen consumption in samples retrieved throughout the lower OMZs hints at efficient exploitation of vertically and laterally advected, oxygenated waters in this zone by aerobic microorganisms. In accordance, metagenomic and metatranscriptomic analyses identified genes encoding for aerobic terminal oxidases and demonstrated their expression by diverse microbial communities, even in virtually anoxic waters. Our results suggest that microaerobic respiration is a major mode of organic matter remineralization and source of ammonium (~45-100%) in the upper oxygen minimum zones, and reconcile hitherto observed mismatches between ammonium producing and consuming processes therein. PMID:26192623

Pilot-Scale Hydrolysis-Aerobic Treatment for Actual Municipal Wastewater: Performance and Microbial Community Analysis

PubMed Central

Bian, Xiao; Wang, Kaijun

2018-01-01

Low-energy cost wastewater treatment is required to change its current energy-intensive status. Although promising, the direct anaerobic digestion of municipal wastewater treatment faces challenges such as low organic content and low temperature, which require further development. The hydrolysis-aerobic system investigated in this study utilized the two well-proven processes of hydrolysis and aerobic oxidation. These have the advantages of efficient COD removal and biodegradability improvement with limited energy cost due to their avoidance of aeration. A pilot-scale hydrolysis-aerobic system was built for performance evaluation with actual municipal wastewater as feed. Results indicated that as high as 39–47% COD removal was achieved with a maximum COD load of 1.10 kg/m3·d. The dominant bacteria phyla included Proteobacteria (36.0%), Planctomycetes (15.4%), Chloroflexi (9.7%), Bacteroidetes (7.7%), Firmicutes (4.4%), Acidobacteria (2.5%), Actinobacteria (1.8%) and Synergistetes (1.3%), while the dominant genera included Thauera (3.42%) and Dechloromonas (3.04%). The absence of methanogens indicates that the microbial community was perfectly retained in the hydrolysis stage instead of in the methane-producing stage. PMID:29522450

Microbial and Isotopic Evidence for Methane Cycling in Hydrocarbon-Containing Groundwater from the Pennsylvania Region

PubMed Central

Vigneron, Adrien; Bishop, Andrew; Alsop, Eric B.; Hull, Kellie; Rhodes, Ileana; Hendricks, Robert; Head, Ian M.; Tsesmetzis, Nicolas

2017-01-01

The Pennsylvania region hosts numerous oil and gas reservoirs and the presence of hydrocarbons in groundwater has been locally observed. However, these methane-containing freshwater ecosystems remain poorly explored despite their potential importance in the carbon cycle. Methane isotope analysis and analysis of low molecular weight hydrocarbon gases from 18 water wells indicated that active methane cycling may be occurring in methane-containing groundwater from the Pennsylvania region. Consistent with this observation, multigenic qPCR and gene sequencing (16S rRNA genes, mcrA, and pmoA genes) indicated abundant populations of methanogens, ANME-2d (average of 1.54 × 104 mcrA gene per milliliter of water) and bacteria associated with methane oxidation (NC10, aerobic methanotrophs, methylotrophs; average of 2.52 × 103 pmoA gene per milliliter of water). Methane cycling therefore likely represents an important process in these hydrocarbon-containing aquifers. The microbial taxa and functional genes identified and geochemical data suggested that (i) methane present is at least in part due to methanogens identified in situ; (ii) Potential for aerobic and anaerobic methane oxidation is important in groundwater with the presence of lineages associated with both anaerobic an aerobic methanotrophy; (iii) the dominant methane oxidation process (aerobic or anaerobic) can vary according to prevailing conditions (oxic or anoxic) in the aquifers; (iv) the methane cycle is closely associated with the nitrogen cycle in groundwater methane seeps with methane and/or methanol oxidation coupled to denitrification or nitrate and nitrite reduction. PMID:28424678

High resolution and comprehensive techniques to analyze aerobic methane oxidation in mesocosm experiments

NASA Astrophysics Data System (ADS)

Chan, E. W.; Kessler, J. D.; Redmond, M. C.; Shiller, A. M.; Arrington, E. C.; Valentine, D. L.; Colombo, F.

2015-12-01

Many studies of microbially mediated aerobic methane oxidation in oceanic environments have examined the many different factors that control the rates of oxidation. However, there is debate on how quickly methane is oxidized once a microbial population is established and what factor(s) are limiting in these types of environments. These factors include the availability of CH4, O2, trace metals, nutrients, and the density of cell population. Limits to these factors can also control the temporal aspects of a methane oxidation event. In order to look at this process in its entirety and with higher temporal resolution, a mesocosm incubation system was developed with a Dissolved Gas Analyzer System (DGAS) coupled with a set of analytical tools to monitor aerobic methane oxidation in real time. With the addition of newer laser spectroscopy techniques (cavity ringdown spectroscopy), stable isotope fractionation caused by microbial processes can also be examined on a real time and automated basis. Cell counting, trace metal, nutrient, and DNA community analyses have also been carried out in conjunction with these mesocosm samples to provide a clear understanding of the biology in methane oxidation dynamics. This poster will detail the techniques involved to provide insights into the chemical and isotopic kinetics controlling aerobic methane oxidation. Proof of concept applications will be presented from seep sites in the Hudson Canyon and the Sleeping Dragon seep field, Mississippi Canyon 118 (MC 118). This system was used to conduct mesocosm experiments to examine methane consumption, O2 consumption, nutrient consumption, and biomass production.

Supplementation with vitamin A enhances oxidative stress in the lungs of rats submitted to aerobic exercise.

PubMed

Gasparotto, Juciano; Petiz, Lyvia Lintzmaier; Girardi, Carolina Saibro; Bortolin, Rafael Calixto; de Vargas, Amanda Rodrigues; Henkin, Bernardo Saldanha; Chaves, Paloma Rodrigues; Roncato, Sabrina; Matté, Cristiane; Zanotto-Filho, Alfeu; Moreira, José Cláudio Fonseca; Gelain, Daniel Pens

2015-12-01

Exercise training induces reactive oxygen species production and low levels of oxidative damage, which are required for induction of antioxidant defenses and tissue adaptation. This process is physiological and essential to improve physical conditioning and performance. During exercise, endogenous antioxidants are recruited to prevent excessive oxidative stress, demanding appropriate intake of antioxidants from diet or supplements; in this context, the search for vitamin supplements that enhance the antioxidant defenses and improve exercise performance has been continuously increasing. On the other hand, excess of antioxidants may hinder the pro-oxidant signals necessary for this process of adaptation. The aim of this study was to investigate the effects of vitamin A supplementation (2000 IU/kg, oral) upon oxidative stress and parameters of pro-inflammatory signaling in lungs of rats submitted to aerobic exercise (swimming protocol). When combined with exercise, vitamin A inhibited biochemical parameters of adaptation/conditioning by attenuating exercise-induced antioxidant enzymes (superoxide dismutase and glutathione peroxidase) and decreasing the content of the receptor for advanced glycation end-products. Increased oxidative damage to proteins (carbonylation) and lipids (lipoperoxidation) was also observed in these animals. In sedentary animals, vitamin A decreased superoxide dismutase and increased lipoperoxidation. Vitamin A also enhanced the levels of tumor necrosis factor alpha and decreased interleukin-10, effects partially reversed by aerobic training. Taken together, the results presented herein point to negative effects associated with vitamin A supplementation at the specific dose here used upon oxidative stress and pro-inflammatory cytokines in lung tissues of rats submitted to aerobic exercise.

Oil refinery wastewater treatment using coupled electrocoagulation and fixed film biological processes

NASA Astrophysics Data System (ADS)

Pérez, Laura S.; Rodriguez, Oscar M.; Reyna, Silvia; Sánchez-Salas, José Luis; Lozada, J. Daniel; Quiroz, Marco A.; Bandala, Erick R.

2016-02-01

Oil refinery wastewater was treated using a coupled treatment process including electrocoagulation (EC) and a fixed film aerobic bioreactor. Different variables were tested to identify the best conditions using this procedure. After EC, the effluent was treated in an aerobic biofilter. EC was capable to remove over 88% of the overall chemical oxygen demand (COD) in the wastewater under the best working conditions (6.5 V, 0.1 M NaCl, 4 electrodes without initial pH adjustment) with total petroleum hydrocarbon (TPH) removal slightly higher than 80%. Aluminum release from the electrodes to the wastewater was found an important factor for the EC efficiency and closely related with several operational factors. Application of EC allowed to increase the biodegradability of the sample from 0.015, rated as non-biodegradable, up to 0.5 widely considered as biodegradable. The effluent was further treated using an aerobic biofilter inoculated with a bacterial consortium including gram positive and gram negative strains and tested for COD and TPH removal from the EC treated effluent during 30 days. Cell count showed the typical bacteria growth starting at day three and increasing up to a maximum after eight days. After day eight, cell growth showed a plateau which agreed with the highest decrease on contaminant concentration. Final TPHs concentration was found about 600 mgL-1 after 30 days whereas COD concentration after biological treatment was as low as 933 mgL-1. The coupled EC-aerobic biofilter was capable to remove up to 98% of the total TPH amount and over 95% of the COD load in the oil refinery wastewater.

Fluid and electrolyte balance during two different preseason training sessions in elite rugby union players.

PubMed

Cosgrove, Samuel D; Love, Thomas D; Brown, Rachel C; Baker, Dane F; Howe, Anna S; Black, Katherine E

2014-02-01

The purpose of this study was to compare fluid balance between a resistance and an aerobic training sessions, in elite rugby players. It is hypothesized that resistance exercise will result in a higher prevalence of overdrinking, whereas during the aerobic session, underdrinking will be more prevalent. As with previous fluid balance studies, this was an observational study. Twenty-six players completed the resistance training session, and 20 players completed the aerobic training session. All players were members of an elite rugby union squad competing in the southern hemisphere's premier competition. For both sessions, players provided a preexercise urine sample to determine hydration status, pre- and postexercise measures of body mass, and blood sodium concentration were taken, and the weight of drink bottles were recorded to calculate sweat rates and fluid intake rates. Sweat patches were positioned on the shoulder of the players, and these remained in place throughout each training session and were later analyzed for sodium concentration. The percentage of sweat loss replaced was higher in the resistance (196 ± 130%) than the aerobic training session (56 ± 17%; p = 0.002). Despite this, no cases of hyponatremia were detected. The results also indicated that more than 80% of players started training in a hypohydrated state. Fluid intake seems to differ depending on the nature of the exercise session. In this group of athletes, players did not match their fluid intakes with their sweat loss, resulting in overdrinking during resistance training and underdrinking in aerobic training. Therefore, hydration strategies and education need to be tailored to the exercise session. Furthermore, given the large number of players arriving at training hypohydrated, improved hydration strategies away from the training venue are required.

Within-Winter Flexibility in Muscle Masses, Myostatin, and Cellular Aerobic Metabolic Intensity in Passerine Birds.

PubMed

Swanson, David L; King, Marisa O; Culver, William; Zhang, Yufeng

Metabolic rates of passerine birds are flexible traits that vary both seasonally and among and within winters. Seasonal variation in summit metabolic rates (M sum = maximum thermoregulatory metabolism) in birds is consistently correlated with changes in pectoralis muscle and heart masses and sometimes with variation in cellular aerobic metabolic intensity, so these traits might also be associated with shorter-term, within-winter variation in metabolic rates. To determine whether these mechanisms are associated with within-winter variation in M sum , we examined the effects of short-term (ST; 0-7 d), medium-term (MT; 14-30 d), and long-term (LT; 30-yr means) temperature variables on pectoralis muscle and heart masses, pectoralis expression of the muscle-growth inhibitor myostatin and its metalloproteinase activators TLL-1 and TLL-2, and pectoralis and heart citrate synthase (CS; an indicator of cellular aerobic metabolic intensity) activities for two temperate-zone resident passerines, house sparrows (Passer domesticus) and dark-eyed juncos (Junco hyemalis). For both species, pectoralis mass residuals were positively correlated with ST temperature variables, suggesting that cold temperatures resulted in increased turnover of pectoralis muscle, but heart mass showed little within-winter variation for either species. Pectoralis mRNA and protein expression of myostatin and the TLLs were only weakly correlated with ST and MT temperature variables, which is largely consistent with trends in muscle masses for both species. Pectoralis and heart CS activities showed weak and variable trends with ST temperature variables in both species, suggesting only minor effects of temperature variation on cellular aerobic metabolic intensity. Thus, neither muscle or heart masses, regulation by the myostatin system, nor cellular aerobic metabolic intensity varied consistently with winter temperature, suggesting that other factors regulate within-winter metabolic variation in these birds.

Aerobic Fitness of Starter and Non-Starter Soccer Players in the Champion’s League

PubMed Central

Paraskevas, Giorgos; Hadjicharalambous, Marios

2018-01-01

Abstract To identify individual response patterns in selected aerobic fitness variables of regular starters (ST; N = 7) and non-starters (Non-ST; N = 10), top level professional soccer players were tested for maximal oxygen uptake (VO2max), velocity at 4 mM of lactate (V4), velocity at maximal oxygen uptake (νVO2max) and oxygen pulse (O2-pulse) in July and December following consecutive periods of fixture congestion. V4 was the only variable that increased significantly in December compared to July (15.1 ± 0.5 vs. 14.6 ± 0.5, p = 0.001). There was an almost certain beneficial large mean team change for V4 (ES = 1.2 (0.67; 1.57), 100/0/0), while beneficial mean team changes were less likely for νVO2max and O2-pulse [ES = 0.31 (-0.08; 0.70), 68/30/2 and ES = 0.24 (0.01; 0.49), 64/36/0, respectively] and unclear for VO2max (ES = 0.02 (-0.31; 0.70), 18/69/13). With the exception of V4 where 10 out of 17 players (7 ST and 3 Non-ST) showed positive changes higher than the biological variability, all other variables were characterized by a substantial proportion of changes lower than the biological variability. The present study demonstrated that aerobic fitness variables that require maximal effort may be characterized by greater variability of the individual response pattern compared to that of submaximal aerobic fitness variables irrespective of the accumulated game time. Submaximal aerobic fitness variables appear to be more informative in the physiological evaluation of top level soccer players and this may be an advantage during exposure to periods of consecutive games. PMID:29599863

Ten days of simulated live high:train low altitude training increases Hbmass in elite water polo players.

PubMed

Garvican-Lewis, Laura A; Clark, Sally A; Polglaze, Ted; McFadden, Greg; Gore, Christopher J

2013-12-01

Water polo requires high aerobic power to meet the demands of match play. Live high:train low (LHTL) may enhance aerobic capacity at sea level. Before the Olympics, the Australian women's water polo team utilised LHTL in an attempt to enhance aerobic fitness. Over 6 months, 11 players completed three normobaric LHTL exposures (block 1:11 days at 3000 m; block 2+3:9 days at 2500 m, 11 days normoxia, 10 days at 2800 m). Haemoglobin mass (Hbmass) was measured through carbon monoxide-rebreathing. Before each block, the relationship between Hbmass and water polo-specific aerobic fitness was investigated using the Multistage Shuttle Swim Test (MSST). Effect size statistics were adopted with likely, highly likely and almost certainly results being >75%, >95%, >99%, respectively. A Pearson product moment correlation was used to characterise the association between pooled data of Hbmass and MSST. Hbmass (mean ± SD, pre 721 ± 66 g) likely increased after block 1 and almost certainly after block 2+3 (% change; 90% confidence limits: block 1: 3.7%; 1.3-6.2%, block 2+3: 4.5%; 3.8-5.1%) and the net effect was almost certainly higher after block 2+3 than before block 1 (pre) by 8.5%; 7.3-9.7%. There was a very large correlation between Hbmass (g/kg) and MSST score (r=0.73). LHTL exposures of <2 weeks induced approximately 4% increase in Hbmass of water polo players. Extra Hbmass may increase aerobic power, but since match performance is nuanced by many factors it is impossible to ascertain whether the increased Hbmass contributed to Australia's Bronze medal.

Efficacy of strengthening or aerobic exercise on pain relief in people with knee osteoarthritis: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Tanaka, Ryo; Ozawa, Junya; Kito, Nobuhiro; Moriyama, Hideki

2013-12-01

We performed a systematic review and meta-analysis of randomized controlled trials to investigate the differences in the efficacies between strengthening and aerobic exercises for pain relief in people with knee osteoarthritis. This search was applied to Medline, Cochrane Central Register of Controlled Trials, the Physiotherapy Evidence Database, and the Cumulative Index to Nursing and Allied Health Literature. All literature published from each source's earliest date to March 2013 was included. Trials comparing the effects of exercise intervention with those of either non-intervention or psycho-educational intervention were collected. Meta-analysis was performed for trials in which therapeutic exercise was carried out with more than three sessions per week up to eight weeks, for pain in people with knee osteoarthritis. All trials were categorised into three subgroups (non-weight-bearing strengthening exercise, weight-bearing strengthening exercise, and aerobic exercise). Subgroup analyses were also performed. Data from eight studies were integrated. Overall effect of exercise was significant with a large effect size (standardised mean difference (SMD): -0.94; 95% confidence interval -1.31 to -0.57). Subgroup analyses showed a larger SMD for non-weight-bearing strengthening exercise (-1.42 [-2.09 to -0.75]) compared with weight-bearing strengthening exercise (-0.70 [-1.05 to -0.35]), and aerobic exercise (-0.45 [-0.77 to -0.13]). Muscle strengthening exercises with or without weight-bearing and aerobic exercises are effective for pain relief in people with knee osteoarthritis. In particular, for pain relief by short-term exercise intervention, the most effective exercise among the three types is non-weight-bearing strengthening exercise.

A genetic predisposition score for muscular endophenotypes predicts the increase in aerobic power after training: the CAREGENE study.

PubMed

Thomaes, Tom; Thomis, Martine; Onkelinx, Steven; Fagard, Robert; Matthijs, Gert; Buys, Roselien; Schepers, Dirk; Cornelissen, Véronique; Vanhees, Luc

2011-10-03

It is widely accepted that genetic variability might explain a large part of the observed heterogeneity in aerobic capacity and its response to training. Significant associations between polymorphisms of different genes with muscular strength, anaerobic phenotypes and body composition have been reported. Muscular endophenotypes are positively correlated with aerobic capacity, therefore, we tested the association of polymorphisms in twelve muscular related genes on aerobic capacity and its response to endurance training. 935 Coronary artery disease patients (CAD) who performed an incremental exercise test until exhaustion at baseline and after three months of training were included. Polymorphisms of the genes were detected using the invader assay. Genotype-phenotype association analyses were performed using ANCOVA. Different models for a genetic predisposition score (GPS) were constructed based on literature and own data and were related to baseline and response VO(2) scores. Carriers of the minor allele in the R23K polymorphism of the glucocorticoid receptor gene (GR) and the ciliary neurotrophic factor gene (CNTF) had a significantly higher increase in peakVO(2) after training (p < 0.05). Carriers of the minor allele (C34T) in the adenosine monophosphate deaminase (AMPD1) gene had a significantly lower relative increase (p < 0.05) in peakVO(2). GPS of data driven models were significantly associated with the increase in peakVO(2) after training. In CAD patients, suggestive associations were found in the GR, CNTF and the AMPD1 gene with an improved change in aerobic capacity after three months of training. Additionally data driven models with a genetic predisposition score (GPS) showed a significant predictive value for the increase in peakVO(2).

A genetic predisposition score for muscular endophenotypes predicts the increase in aerobic power after training: the CAREGENE study

PubMed Central

2011-01-01

Background It is widely accepted that genetic variability might explain a large part of the observed heterogeneity in aerobic capacity and its response to training. Significant associations between polymorphisms of different genes with muscular strength, anaerobic phenotypes and body composition have been reported. Muscular endophenotypes are positively correlated with aerobic capacity, therefore, we tested the association of polymorphisms in twelve muscular related genes on aerobic capacity and its response to endurance training. Methods 935 Coronary artery disease patients (CAD) who performed an incremental exercise test until exhaustion at baseline and after three months of training were included. Polymorphisms of the genes were detected using the invader assay. Genotype-phenotype association analyses were performed using ANCOVA. Different models for a genetic predisposition score (GPS) were constructed based on literature and own data and were related to baseline and response VO2 scores. Results Carriers of the minor allele in the R23K polymorphism of the glucocorticoid receptor gene (GR) and the ciliary neurotrophic factor gene (CNTF) had a significantly higher increase in peakVO2 after training (p < 0.05). Carriers of the minor allele (C34T) in the adenosine monophosphate deaminase (AMPD1) gene had a significantly lower relative increase (p < 0.05) in peakVO2. GPS of data driven models were significantly associated with the increase in peakVO2 after training. Conclusions In CAD patients, suggestive associations were found in the GR, CNTF and the AMPD1 gene with an improved change in aerobic capacity after three months of training. Additionally data driven models with a genetic predisposition score (GPS) showed a significant predictive value for the increase in peakVO2. PMID:21967077

Behaviour and fate of nine recycled water trace organics during managed aquifer recharge in an aerobic aquifer

NASA Astrophysics Data System (ADS)

Patterson, B. M.; Shackleton, M.; Furness, A. J.; Bekele, E.; Pearce, J.; Linge, K. L.; Busetti, F.; Spadek, T.; Toze, S.

2011-03-01

The fate of nine trace organic compounds was evaluated during a 12 month large-scale laboratory column experiment. The columns were packed with aquifer sediment and evaluated under natural aerobic and artificial anaerobic geochemical conditions, to assess the potential for natural attenuation of these compounds during aquifer passage associated with managed aquifer recharge (MAR). The nine trace organic compounds were bisphenol A (BPA), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), N-nitrosodimethylamine (NDMA), N-nitrosomorpholine (NMOR), carbamazepine, oxazepam, iohexol and iodipamide. In the low organic carbon content Spearwood sediment, all trace organics were non-retarded with retardation coefficients between 1.0 and 1.2, indicating that these compounds would travel at near groundwater velocities within the aquifer. The natural aerobic geochemical conditions provided a suitable environment for the rapid degradation for BPA, E2, iohexol (half life < 1 day). Lag-times for the start of degradation of these compounds ranged from < 15 to 30 days. While iodipamide was persistent under aerobic conditions, artificial reductive geochemical conditions promoted via the addition of ethanol, resulted in rapid degradation (half life < 1 days). Pharmaceuticals (carbamazepine and oxazepam) and disinfection by-products (NDMA and NMOR) did not degrade under either aerobic or anaerobic aquifer geochemical conditions (half life > 50 days). Field-based validation experiments with carbamazepine and oxazepam also showed no degradation. If persistent trace organics are present in recycled waters at concentrations in excess of their intended use, natural attenuation during aquifer passage alone may not result in extracted water meeting regulatory requirements. Additional pre treatment of the recycled water would therefore be required.

Physical activity interventions for people with mental illness: a systematic review and meta-analysis.

PubMed

Rosenbaum, Simon; Tiedemann, Anne; Sherrington, Catherine; Curtis, Jackie; Ward, Philip B

2014-09-01

To determine effects of physical activity on depressive symptoms (primary objective), symptoms of schizophrenia, anthropometric measures, aerobic capacity, and quality of life (secondary objectives) in people with mental illness and explore between-study heterogeneity. MEDLINE, Cochrane Controlled Trials Register, PsycINFO, CINAHL, Embase, and the Physiotherapy Evidence Database (PEDro) were searched from earliest record to 2013. Randomized controlled trials of adults with a DSM-IV-TR, ICD-10, or clinician-confirmed diagnosis of a mental illness other than dysthymia or eating disorders were selected. Interventions included exercise programs, exercise counseling, lifestyle interventions, tai chi, or physical yoga. Study methodological quality and intervention compliance with American College of Sports Medicine (ACSM) guidelines were also assessed. Two investigators extracted data. Data were pooled using random-effects meta-analysis. Meta-regression was used to examine sources of between-study heterogeneity. Thirty-nine eligible trials were identified. The primary meta-analysis found a large effect of physical activity on depressive symptoms (n = 20; standardized mean difference (SMD) = 0.80). The effect size in trial interventions that met ACSM guidelines for aerobic exercise did not differ significantly from those that did not meet these guidelines. The effect for trials with higher methodological quality was smaller than that observed for trials with lower methodological quality (SMD = 0.39 vs 1.35); however, the difference was not statistically significant. A large effect was found for schizophrenia symptoms (SMD = 1.0), a small effect was found for anthropometry (SMD = 0.24), and moderate effects were found for aerobic capacity (SMD = 0.63) and quality of life (SMD = 0.64). Physical activity reduced depressive symptoms in people with mental illness. Larger effects were seen in studies of poorer methodological quality. Physical activity reduced symptoms of schizophrenia and improved anthropometric measures, aerobic capacity, and quality of life among people with mental illness. PROSPERO registration #CRD42012002012. © Copyright 2014 Physicians Postgraduate Press, Inc.

Feasibility of a combined aerobic and strength training program and its effects on cognitive and physical function in institutionalized dementia patients. A pilot study.

PubMed

Bossers, Willem J R; Scherder, Erik J A; Boersma, Froukje; Hortobágyi, Tibor; van der Woude, Lucas H V; van Heuvelen, Marieke J G

2014-01-01

We examined the feasibility of a combined aerobic and strength training program in institutionalized dementia patients and studied the effects on cognitive and physical function. Thirty-three patients with dementia, recruited from one nursing home, participated in this non-randomized pilot study (25 women; age = 85.2±4.9 years; Mini Mental State Examination = 16.8±4.0). In phase 1 of the study, seventeen patients in the Exercise group (EG) received a combined aerobic and strength training program for six weeks, five times per week, 30 minutes per session, in an individually supervised format and successfully concluded the pre and posttests. In phase 2 of the study, sixteen patients in the Social group (SG) received social visits at the same frequency, duration, and format and successfully concluded the pre and posttests. Indices of feasibility showed that the recruitment and adherence rate, respectively were 46.2% and 86.3%. All EG patients completed the exercise program according to protocol without adverse events. After the six-week program, no significant differences on cognitive function tests were found between the EG and SG. There was a moderate effect size in favor for the EG for the Visual Memory Span Forward; a visual attention test. There were significant differences between groups in favor for the EG with moderate to large effects for the physical tests Walking Speed (p = .003), Six-Minute Walk Test (p = .031), and isometric quadriceps strength (p = .012). The present pilot study showed that it is feasible to conduct a combined aerobic and strength training program in institutionalized patients with dementia. The selective cognitive visual attention improvements and more robust changes in motor function in favor of EG vs. SG could serve as a basis for large randomized clinical trials. trialregister.nl 1230.

The Importance of Transition Metals in the Expanding Network of Microbial Metabolism in the Archean Eon

NASA Astrophysics Data System (ADS)

Moore, E. K.; Jelen, B. I.; Giovannelli, D.; Prabhu, A.; Raanan, H.; Falkowski, P. G.

2017-12-01

Deep time changes in Earth surface redox conditions, particularly due to global oxygenation, has impacted the availability of different metals and substrates that are central in biology. Oxidoreductase proteins are molecular nanomachines responsible for all biological electron transfer processes across the tree of life. These enzymes largely contain transition metals in their active sites. Microbial metabolic pathways form a global network of electron transfer, which expanded throughout the Archean eon. Older metabolisms (sulfur reduction, methanogenesis, anoxygenic photosynthesis) accessed negative redox potentials, while later evolving metabolisms (oxygenic photosynthesis, nitrification/denitrification, aerobic respiration) accessed positive redox potentials. The incorporation of different transition metals facilitated biological innovation and the expansion of the network of microbial metabolism. Network analysis was used to examine the connections between microbial taxa, metabolic pathways, crucial metallocofactors, and substrates in deep time by incorporating biosignatures preserved in the geologic record. Nitrogen fixation and aerobic respiration have the highest level of betweenness among metabolisms in the network, indicating that the oldest metabolisms are not the most central. Fe has by far the highest betweenness among metals. Clustering analysis largely separates High Metal Bacteria (HMB), Low Metal Bacteria (LMB), and Archaea showing that simple un-weighted links between taxa, metabolism, and metals have phylogenetic relevance. On average HMB have the highest betweenness among taxa, followed by Archaea and LMB. There is a correlation between the number of metallocofactors and metabolic pathways in representative bacterial taxa, but Archaea do not follow this trend. In many cases older and more recently evolved metabolisms were clustered together supporting previous findings that proliferation of metabolic pathways is not necessarily chronological.

Biotreatment from hot bugs to cold ducks

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-02-01

There are few forms of industrial wastes that cannot be neutralized and disposed of using modern treatment methods. The challenge is to control costs and minimize liability. Such is the quandary for waste treatment facilities dealing with biological sludge. One way to reduce sludge volume is to use a high-temperature aerobic treatment process, such as the one recently commercialized by US Filter. The process relies on a strain of bacteria heated to 50--65 C. The high temperatures destroy pathogens and speed metabolism. Cultivated in a lagoon or pond treatment system, the duckweed floats on top of the water and feedsmore » on the organics. The plants consume nitrogen, ammonia and phosphoric compounds, help retain aerobic conditions in the pond, and control algae growth by blocking sunlight.« less

Removal of organic compounds from shale gas flowback water.

PubMed

Butkovskyi, Andrii; Faber, Ann-Hélène; Wang, Yue; Grolle, Katja; Hofman-Caris, Roberta; Bruning, Harry; Van Wezel, Annemarie P; Rijnaarts, Huub H M

2018-07-01

Ozonation, sorption to granular activated carbon and aerobic degradation were compared as potential treatment methods for removal of dissolved organic carbon (DOC) fractions and selected organic compounds from shale gas flowback water after pre-treatment in dissolved air flotation unit. Flowback water was characterised by high chemical oxygen demand and DOC. Low molecular weight (LMW) acids and neutral compounds were the most abundant organic fractions, corresponding to 47% and 35% of DOC respectively. Ozonation did not change distribution of organic carbon fractions and concentrations of detected individual organic compounds significantly. Sorption to activated carbon targeted removal of individual organic compounds with molecular weight >115 Da, whereas LMW compounds remained largely unaffected. Aerobic degradation was responsible for removal of LMW compounds and partial ammonium removal, whereas formation of intermediates with molecular weight of 200-350 Da was observed. Combination of aerobic degradation for LMW organics removal with adsorption to activated carbon for removal of non-biodegradable organics is proposed to be implemented between pre-treatment (dissolved air floatation) and desalination (thermal or membrane desalination) steps. Copyright © 2018 Elsevier Ltd. All rights reserved.

Microbial oxidation as a methane sink beneath the West Antarctic Ice Sheet

NASA Astrophysics Data System (ADS)

Michaud, Alexander B.; Dore, John E.; Achberger, Amanda M.; Christner, Brent C.; Mitchell, Andrew C.; Skidmore, Mark L.; Vick-Majors, Trista J.; Priscu, John C.

2017-08-01

Aquatic habitats beneath ice masses contain active microbial ecosystems capable of cycling important greenhouse gases, such as methane (CH4). A large methane reservoir is thought to exist beneath the West Antarctic Ice Sheet, but its quantity, source and ultimate fate are poorly understood. For instance, O2 supplied by basal melting should result in conditions favourable for aerobic methane oxidation. Here we use measurements of methane concentrations and stable isotope compositions along with genomic analyses to assess the sources and cycling of methane in Subglacial Lake Whillans (SLW) in West Antarctica. We show that sub-ice-sheet methane is produced through the biological reduction of CO2 using H2. This methane pool is subsequently consumed by aerobic, bacterial methane oxidation at the SLW sediment-water interface. Bacterial oxidation consumes >99% of the methane and represents a significant methane sink, and source of biomass carbon and metabolic energy to the surficial SLW sediments. We conclude that aerobic methanotrophy may mitigate the release of methane to the atmosphere upon subglacial water drainage to ice sheet margins and during periods of deglaciation.

Aerobic exercise interventions for adults living with HIV/AIDS.

PubMed

O'Brien, Kelly; Nixon, Stephanie; Tynan, Anne-Marie; Glazier, Richard

2010-08-04

Access to combination antiretroviral therapy has turned HIV into a chronic and manageable disease for many. This increased chronicity has been mirrored by increased prevalence of health-related challenges experienced by people living with HIV (Rusch 2004). Exercise is a key strategy for people living with HIV and by rehabilitation professionals to address these disablements; however, knowledge about the effects of exercise among adults living with HIV still is emerging. To examine the safety and effectiveness of aerobic exercise interventions on immunologic and virologic, cardiopulmonary, psychologic outcomes and strength, weight, and body composition in adults living with HIV. Searches of MEDLINE, EMBASE, SCIENCE CITATION INDEX, CINAHL, HEALTHSTAR, PsycINFO, SPORTDISCUS and Cochrane Review Group Databases were conducted between 1980 and June 2009. Searches of published and unpublished abstracts and proceedings from major international and national HIV/AIDS conferences were conducted, as well as a handsearch of reference lists and tables of contents of relevant journals and books. We included studies of randomised controlled trials (RCTs) comparing aerobic exercise interventions with no aerobic exercise interventions or another exercise or treatment modality, performed at least three times per week for at least four weeks among adults (18 years of age or older) living with HIV. Data on study design, participants, interventions, outcomes, and methodological quality were abstracted from included studies by two reviewers. Meta-analyses, using RevMan 5 computer software, were performed on outcomes when possible. A total of 14 studies met inclusion criteria for this review and 30 meta-analyses over several updates were performed. Main results indicated that performing constant or interval aerobic exercise, or a combination of constant aerobic exercise and progressive resistive exercise for at least 20 minutes at least three times per week for at least five weeks appears to be safe and may lead to significant improvements in selected outcomes of cardiopulmonary fitness (maximum oxygen consumption), body composition (leg muscle area, percent body fat), and psychological status (depression-dejection symptoms). These findings are limited to participants who continued to exercise and for whom there were adequate follow-up data. Aerobic exercise appears to be safe and may be beneficial for adults living with HIV. These findings are limited by the small sample sizes and large withdrawal rates described in the studies. Future research would benefit from participant follow-up and intention-to-treat analysis. Further research is required to determine the optimal parameters in which aerobic exercise may be most beneficial for adults living with HIV.

[Cognitive training combined with aerobic exercises in multiple sclerosis patients: a pilot study].

PubMed

Jimenez-Morales, R M; Herrera-Jimenez, L F; Macias-Delgado, Y; Perez-Medinilla, Y T; Diaz-Diaz, S M; Forn, C

2017-06-01

The scientific evidences associated to the effectiveness of different techniques of cognitive rehabilitation are still contradictory. To compare a program of combined training (physical and cognitive) in front of a program of physical training and to observe their effectiveness about the optimization of the cognitive functions in patients with multiple sclerosis (MS). It was carried out an experimental study in 32 patients with MS. The patients were distributed in two groups: 16 to the experimental group (combined cognitive training with aerobic exercises) and 16 patients to the control group (aerobic exercises). The intervention was planned for six weeks combining cognitive tasks by means of a game of dynamic board of cubes and signs (TaDiCS ®) and a program of aerobic exercises. The Brief Repeatable Battery of Neuropsychological Test and the Stroop Test were applied to evaluate the cognitive yield. Also, the Beck Depression Inventory was administered. There were found significant differences in the intergrupal analysis after the intervention in the variable learning and visuoespacial long term memory (p = 0.000), attention (p = 0.026) and inhibitory control (p = 0.007). Also, in the intragroup analysis there were found significant differences in these variables and information processing speed in the group that received the combined training. These patients also showed a significant improvement in the emotional state (p = 0.043). The cognitive training combined with the aerobic exercises is effective to improve the cognitive performance.

An obligately aerobic soil bacterium activates fermentative hydrogen production to survive reductive stress during hypoxia

PubMed Central

Berney, Michael; Greening, Chris; Conrad, Ralf; Jacobs, William R.; Cook, Gregory M.

2014-01-01

Oxygen availability is a major factor and evolutionary force determining the metabolic strategy of bacteria colonizing an environmental niche. In the soil, conditions can switch rapidly between oxia and anoxia, forcing soil bacteria to remodel their energy metabolism accordingly. Mycobacterium is a dominant genus in the soil, and all its species are obligate aerobes. Here we show that an obligate aerobe, the soil actinomycete Mycobacterium smegmatis, adopts an anaerobe-type strategy by activating fermentative hydrogen production to adapt to hypoxia. This process is controlled by the two-component system DosR-DosS/DosT, an oxygen and redox sensor that is well conserved in mycobacteria. We show that DosR tightly regulates the two [NiFe]-hydrogenases: Hyd3 (MSMEG_3931-3928) and Hyd2 (MSMEG_2719-2718). Using genetic manipulation and high-sensitivity GC, we demonstrate that Hyd3 facilitates the evolution of H2 when oxygen is depleted. Combined activity of Hyd2 and Hyd3 was necessary to maintain an optimal NAD+/NADH ratio and enhanced adaptation to and survival of hypoxia. We demonstrate that fermentatively-produced hydrogen can be recycled when fumarate or oxygen become available, suggesting Mycobacterium smegmatis can switch between fermentation, anaerobic respiration, and aerobic respiration. Hydrogen metabolism enables this obligate aerobe to rapidly meet its energetic needs when switching between microoxic and anoxic conditions and provides a competitive advantage in low oxygen environments. PMID:25049411

Wellness Wednesday. Invite Guests To Work Out with Students.

ERIC Educational Resources Information Center

Avalos, Benjamin

1996-01-01

Teachers in a large, urban school district created Wellness Wednesday, a program in which students invite family members and school staff members to join them every other Wednesday for an aerobic workout. The article describes how the program works and notes successful program ideas. (SM)

Physicochemical treatments of anionic surfactants wastewater: Effect on aerobic biodegradability.

PubMed

Aloui, Fathi; Kchaou, Sonia; Sayadi, Sami

2009-05-15

The effect of different physicochemical treatments on the aerobic biodegradability of an industrial wastewater resulting from a cosmetic industry has been investigated. This industrial wastewater contains 11423 and 3148mgL(-1) of chemical oxygen demand (COD) and anionic surfactants, respectively. The concentration of COD and anionic surfactants were followed throughout the diverse physicochemical treatments and biodegradation experiments. Different pretreatments of this industrial wastewater using chemical flocculation process with lime and aluminium sulphate (alum), and also advanced oxidation process (electro-coagulation (Fe and Al) and electro-Fenton) led to important COD and anionic surfactants removals. The best results were obtained using electro-Fenton process, exceeding 98 and 80% of anionic surfactants and COD removals, respectively. The biological treatment by an isolated strain Citrobacter braakii of the surfactant wastewater, as well as the pretreated wastewater by the various physicochemical processes used in this study showed that the best results were obtained with electro-Fenton pretreated wastewater. The characterization of the treated surfactant wastewater by the integrated process (electro-coagulation or electro-Fenton)-biological showed that it respects Tunisian discharge standards.

An evaluation of three processing methods and the effect of reduced culture times for faster direct identification of pathogens from BacT/ALERT blood cultures by MALDI-TOF MS.

PubMed

Loonen, A J M; Jansz, A R; Stalpers, J; Wolffs, P F G; van den Brule, A J C

2012-07-01

Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) is a fast and reliable method for the identification of bacteria from agar media. Direct identification from positive blood cultures should decrease the time to obtaining the result. In this study, three different processing methods for the rapid direct identification of bacteria from positive blood culture bottles were compared. In total, 101 positive aerobe BacT/ALERT bottles were included in this study. Aliquots from all bottles were used for three bacterial processing methods, i.e. the commercially available Bruker's MALDI Sepsityper kit, the commercially available Molzym's MolYsis Basic5 kit and a centrifugation/washing method. In addition, the best method was used to evaluate the possibility of MALDI application after a reduced incubation time of 7 h of Staphylococcus aureus- and Escherichia coli-spiked (1,000, 100 and 10 colony-forming units [CFU]) aerobe BacT/ALERT blood cultures. Sixty-six (65%), 51 (50.5%) and 79 (78%) bottles were identified correctly at the species level when the centrifugation/washing method, MolYsis Basic 5 and Sepsityper were used, respectively. Incorrect identification was obtained in 35 (35%), 50 (49.5%) and 22 (22%) bottles, respectively. Gram-positive cocci were correctly identified in 33/52 (64%) of the cases. However, Gram-negative rods showed a correct identification in 45/47 (96%) of all bottles when the Sepsityper kit was used. Seven hours of pre-incubation of S. aureus- and E. coli-spiked aerobe BacT/ALERT blood cultures never resulted in reliable identification with MALDI-TOF MS. Sepsityper is superior for the direct identification of microorganisms from aerobe BacT/ALERT bottles. Gram-negative pathogens show better results compared to Gram-positive bacteria. Reduced incubation followed by MALDI-TOF MS did not result in faster reliable identification.

Sulfur Cycling Mediates Calcium Carbonate Geochemistry in Modern Marine Stromatolites

NASA Technical Reports Server (NTRS)

Visscher, P. T.; Hoeft, S. E.; Bebout, B. M.; Reid, R. P.

2004-01-01

Modem marine stromatolites forming in Highborne Cay, Exumas (Bahamas), contain microbial mats dominated by Schizothrix. Although saturating concentrations of Ca2+ and CO32- exist, microbes mediate CaCO3 precipitation. Cyanobacterial photosynthesis in these stromatolites aids calcium carbonate precipitation by removal of HS+ through CO2 use. Photorespiration and exopolymer production predominantly by oxygenic phototrophs fuel heterotrophic activity: aerobic respiration (approximately 60 umol/sq cm.h) and sulfate reduction (SR; 1.2 umol SO42-/sq cm.h) are the dominant C- consuming processes. Aerobic microbial respiration and the combination of SR and H2S oxidation both facilitate CaCO3 dissolution through H+ production. Aerobic respiration consumes much more C on an hourly basis, but duel fluctuating O2 and H2 depth profiles indicate that overall, SR consumes only slightly less (0.2-0.5) of the primary production. Moreover, due to low O2 concentrations when SR rates are peaking, reoxidation of the H2S formed is incomplete: both thiosulfate and polythionates are formed. The process of complete H2S oxidation yields H+. However, due to a low O2 concentration late in the day and relatively high O2 concentrations early in the following morning, a two-stage oxidation takes place: first, polythionates are formed from H2S, creating alkalinity which coincides with CaCO3 precipitation; secondly, oxidation of polythionates to sulfate yields acidity, resulting in dissolution, etc. Vertical profiles confirmed that the pH peaked late in the afternoon (greater than 8.8) and had the lowest values (less than 7.4) early in the morning. Thus, the effect of this S-cycling through alkalinity production, followed by acidification during H2S oxidation, results in a six times stronger fluctuation in acidity than photosynthesis plus aerobic respiration accomplish. This implies that anaerobic processes play a pivotal role in stromatolite formation.

Iron and zinc isotope fractionation during uptake and translocation in rice (Oryza sativa) grown in oxic and anoxic soils

NASA Astrophysics Data System (ADS)

Arnold, Tim; Markovic, Tamara; Kirk, Guy J. D.; Schönbächler, Maria; Rehkämper, Mark; Zhao, Fangjie J.; Weiss, Dominik J.

2015-11-01

Stable isotope fractionation is emerging quickly as a powerful novel technique to study metal uptake and translocation in plants. Fundamental to this development is a thorough understanding of the processes that lead to isotope fractionation under differing environmental conditions. In this study, we investigated Zn and Fe isotope fractionation in rice grown to maturity in anaerobic and aerobic soils under greenhouse conditions. The overall Zn isotope fractionation between the soil and above ground plant material was negligible in aerobic soil but significant in anaerobic soil with isotopically lighter Zn in the rice plant. The observed range of fractionation is in line with previously determined fractionations of Zn in rice grown in hydroponic solutions and submerged soils and emphasizes the effect of taking up different chemical forms of Zn, most likely free and organically complexed Zn. The Zn in the grain was isotopically lighter than in the rest of the above ground plant in rice grown in aerobic and anaerobic soils alike. This suggests that in the course of the grain loading and during the translocation within the plant important biochemical and/or biophysical processes occur. The isotope fractionation observed in the grains would be consistent with an unidirectional controlled transport from shoot to grain with a fractionation factor of α ≈ 0.9994. Iron isotopes showed an isotopic lighter signature in shoot and grain compared to the bulk soil or the leachate in aerobic and anaerobic soils alike. The negative direction of isotopic fractionation is consistent with possible changes in the redox state of Fe occurring during the uptake and translocation processes. The isotope fractionation pattern between shoots and grain material are different for Zn and Fe which finally suggests that different mechanisms operate during translocation and grain-loading in rice for these two key micronutrients.

Treatment of an actual slaughterhouse wastewater by integration of biological and advanced oxidation processes: Modeling, optimization, and cost-effectiveness analysis.

PubMed

Bustillo-Lecompte, Ciro Fernando; Mehrvar, Mehrab

2016-11-01

Biological and advanced oxidation processes are combined to treat an actual slaughterhouse wastewater (SWW) by a sequence of an anaerobic baffled reactor, an aerobic activated sludge reactor, and a UV/H2O2 photoreactor with recycle in continuous mode at laboratory scale. In the first part of this study, quadratic modeling along with response surface methodology are used for the statistical analysis and optimization of the combined process. The effects of the influent total organic carbon (TOC) concentration, the flow rate, the pH, the inlet H2O2 concentration, and their interaction on the overall treatment efficiency, CH4 yield, and H2O2 residual in the effluent of the photoreactor are investigated. The models are validated at different operating conditions using experimental data. Maximum TOC and total nitrogen (TN) removals of 91.29 and 86.05%, respectively, maximum CH4 yield of 55.72%, and minimum H2O2 residual of 1.45% in the photoreactor effluent were found at optimal operating conditions. In the second part of this study, continuous distribution kinetics is applied to establish a mathematical model for the degradation of SWW as a function of time. The agreement between model predictions and experimental values indicates that the proposed model could describe the performance of the combined anaerobic-aerobic-UV/H2O2 processes for the treatment of SWW. In the final part of the study, the optimized combined anaerobic-aerobic-UV/H2O2 processes with recycle were evaluated using a cost-effectiveness analysis to minimize the retention time, the electrical energy consumption, and the overall incurred treatment costs required for the efficient treatment of slaughterhouse wastewater effluents. Copyright © 2016 Elsevier Ltd. All rights reserved.

Microbiota dynamics and diversity at different stages of industrial processing of cocoa beans into cocoa powder.

PubMed

Lima, Lídia J R; van der Velpen, Vera; Wolkers-Rooijackers, Judith; Kamphuis, Henri J; Zwietering, Marcel H; Nout, M J Rob

2012-04-01

We sampled a cocoa powder production line to investigate the impact of processing on the microbial community size and diversity at different stages. Classical microbiological methods were combined with 16S rRNA gene PCR-denaturing gradient gel electrophoresis, coupled with clone library construction, to analyze the samples. Aerobic thermoresistant spores (ThrS) (100°C; 10 min) were also isolated and characterized (identity, genetic diversity, and spore heat resistance), in view of their relevance to the quality of downstream heat-treated cocoa-flavored drinks. In the nibs (broken, shelled cocoa beans), average levels of total aerobic microorganisms (TAM) (4.4 to 5.6 log CFU/g) and aerobic total spores (TS) (80°C; 10 min; 4.3 to 5.5 log CFU/g) were significantly reduced (P < 0.05) as a result of alkalizing, while fungi (4.2 to 4.4 log CFU/g) and Enterobacteriaceae (1.7 to 2.8 log CFU/g) were inactivated to levels below the detection limit, remaining undetectable throughout processing. Roasting further decreased the levels of TAM and TS, but they increased slightly during subsequent processing. Molecular characterization of bacterial communities based on enriched cocoa samples revealed a predominance of members of the Bacillaceae, Pseudomonadaceae, and Enterococcaceae. Eleven species of ThrS were found, but Bacillus licheniformis and the Bacillus subtilis complex were prominent and revealed great genetic heterogeneity. We concluded that the microbiota of cocoa powder resulted from microorganisms that could have been initially present in the nibs, as well as microorganisms that originated during processing. B. subtilis complex members, particularly B. subtilis subsp. subtilis, formed the most heat-resistant spores. Their occurrence in cocoa powder needs to be considered to ensure the stability of derived products, such as ultrahigh-temperature-treated chocolate drinks.

Aerobic Food Waste Composting: Measurement of Green House Gases

NASA Astrophysics Data System (ADS)

Chung, J.

2016-12-01

Greenhouse gases (GHGs) are a major cause of global warming. While food waste composting can reduce the amount of waste being sent to traditional landfills, it also produces GHGs during the process. The objective of this research is to evaluate the GHGs emitted from an aerobic food composting machine, which is used in ISF. The Independent Schools Foundation Academy is a private independent school in Hong Kong with approximately 1500 students. Each academic year, the school produces 27 metric tons of food waste. In November 2013, the school installed a food waste composting system. Over the past 3 years, various improvements, such as installing a bio-filter to reduce the smell of the compost, have been made to the composting process. Meanwhile the compost is used by the primary students, as part of their experiential learning curriculum and organic farming projects. The composting process employs two machines: the Dehydra and A900 Rocket. The Dehydra reduces the mass of the food waste by separating the ground food waste and excessive water. The A900 Rocket, a composter made by Tidy Planet, processes food waste into compost in 14 days. This machine runs in an aerobic process, in which oxygen is used as an input gas and gases, such as carbon dioxide, are released. Carbon Dioxide is one of the greenhouse gases (GHGs). This research focuses on GHGs that are emitted from the A900 Rocket. The data is collected by the Gasmet DX 4015, a Fourier transform infrared spectroscopy (FTIR) multi gas analyser. This equipment measures the concentration (ppm) of different GHGs, including N2O, CO2, CH4, NH3 and CO.

Microbiota Dynamics and Diversity at Different Stages of Industrial Processing of Cocoa Beans into Cocoa Powder

PubMed Central

Lima, Lídia J. R.; van der Velpen, Vera; Wolkers-Rooijackers, Judith; Kamphuis, Henri J.; Nout, M. J. Rob

2012-01-01

We sampled a cocoa powder production line to investigate the impact of processing on the microbial community size and diversity at different stages. Classical microbiological methods were combined with 16S rRNA gene PCR-denaturing gradient gel electrophoresis, coupled with clone library construction, to analyze the samples. Aerobic thermoresistant spores (ThrS) (100°C; 10 min) were also isolated and characterized (identity, genetic diversity, and spore heat resistance), in view of their relevance to the quality of downstream heat-treated cocoa-flavored drinks. In the nibs (broken, shelled cocoa beans), average levels of total aerobic microorganisms (TAM) (4.4 to 5.6 log CFU/g) and aerobic total spores (TS) (80°C; 10 min; 4.3 to 5.5 log CFU/g) were significantly reduced (P < 0.05) as a result of alkalizing, while fungi (4.2 to 4.4 log CFU/g) and Enterobacteriaceae (1.7 to 2.8 log CFU/g) were inactivated to levels below the detection limit, remaining undetectable throughout processing. Roasting further decreased the levels of TAM and TS, but they increased slightly during subsequent processing. Molecular characterization of bacterial communities based on enriched cocoa samples revealed a predominance of members of the Bacillaceae, Pseudomonadaceae, and Enterococcaceae. Eleven species of ThrS were found, but Bacillus licheniformis and the Bacillus subtilis complex were prominent and revealed great genetic heterogeneity. We concluded that the microbiota of cocoa powder resulted from microorganisms that could have been initially present in the nibs, as well as microorganisms that originated during processing. B. subtilis complex members, particularly B. subtilis subsp. subtilis, formed the most heat-resistant spores. Their occurrence in cocoa powder needs to be considered to ensure the stability of derived products, such as ultrahigh-temperature-treated chocolate drinks. PMID:22327588

Anaerobic Biodegradation of Detergent Surfactants

PubMed Central

Merrettig-Bruns, Ute; Jelen, Erich

2009-01-01

Detergent surfactants can be found in wastewater in relevant concentrations. Most of them are known as ready degradable under aerobic conditions, as required by European legislation. Far fewer surfactants have been tested so far for biodegradability under anaerobic conditions. The natural environment is predominantly aerobic, but there are some environmental compartments such as river sediments, sub-surface soil layer and anaerobic sludge digesters of wastewater treatment plants which have strictly anaerobic conditions. This review gives an overview on anaerobic biodegradation processes, the methods for testing anaerobic biodegradability, and the anaerobic biodegradability of different detergent surfactant types (anionic, nonionic, cationic, amphoteric surfactants).

Copper-catalyzed aerobic oxidative N-S bond functionalization for C-S bond formation: regio- and stereoselective synthesis of sulfones and thioethers.

PubMed

Li, Xianwei; Xu, Yanli; Wu, Wanqing; Jiang, Chang; Qi, Chaorong; Jiang, Huanfeng

2014-06-23

A regio- and stereoselective synthesis of sulfones and thioethers by means of Cu(I)-catalyzed aerobic oxidative N-S bond cleavage of sulfonyl hydrazides, followed by cross-coupling reactions with alkenes and aromatic compounds to form the C sp 2-S bond, is described herein. N2 and H2O are the byproducts of this transformation, thus offering an environmentally benign process with a wide range of potential applications in organic synthesis and medicinal chemistry. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Aerobic Reduction of Arsenate by a Bacterium Isolated From Activated Sludge

NASA Astrophysics Data System (ADS)

Kozai, N.; Ohnuki, T.; Hanada, S.; Nakamura, K.; Francis, A. J.

2006-12-01

Microlunatus phosphovorus strain NM-1 is a polyphosphate-accumulating bacterium isolated from activated sludge. This bacterium takes up a large amount of polyphosphate under aerobic conditions and release phosphate ions by hydrolysis of polyphosphate to orthophosphate under anaerobic conditions to derive energy for taking up substrates. To understand the nature of this strain, especially, influence of potential contaminants in sewage and wastewater on growth, we have been investigating behavior of this bacterium in media containing arsenic. The present paper mainly reports reduction of arsenate by this bacterium under aerobic conditions. The strain NM-1 (JCM 9379) was aerobically cultured at 30 °C in a nutrient medium containing 2.5 g/l peptone, 0.5 g/l glucose, 1.5 g/l yeast extract, and arsenic [Na2HAsO4 (As(V)) or Na3AsO3 (As(III))] at concentrations between 0 and 50 mM. The cells collected from arsenic-free media were dispersed in buffer solutions containing 2mM HEPES, 10mM NaCl, prescribed concentrations of As(V), and 0-0.2 percent glucose. Then, this cell suspension was kept at 20 °C under aerobic or anaerobic conditions. The speciation of arsenic was carried out by ion chromatography and ICP-MS. The growth of the strain under aerobic conditions was enhanced by the addition of As(V) at the concentration between 1 and 10 mM. The maximum optical density of the culture in the medium containing 5mM As(V) was 1.4 times greater than that of the control culture. Below the As(V) concentration of 10mM, most of the As(V) was reduced to As(III). The growth of the strain under anaerobic conditions has not been observed so far. The cells in the buffer solutions reduced As(V) under aerobic condition. The reduction was enhanced by the addition of glucose. However, the cell did not reduce As(V) under anaerobic conditions. The strain NM-1 showed high resistance to As(V) and As(III). The maximum optical density of the culture grown in a medium containing 50 mM As(V) was only 20 percent lower than that of the control culture.

Epstein-Barr Virus-Encoded Latent Membrane Protein 1 Upregulates Glucose Transporter 1 Transcription via the mTORC1/NF-κB Signaling Pathways

PubMed Central

Zhang, Jun; Jia, Lin; Lin, Weitao; Yip, Yim Ling; Lo, Kwok Wai; Lau, Victoria Ming Yi; Zhu, Dandan; Tsang, Chi Man; Zhou, Yuan; Deng, Wen; Lung, Hong Lok; Lung, Maria Li; Cheung, Lai Man

2017-01-01

ABSTRACT Accumulating evidence indicates that oncogenic viral protein plays a crucial role in activating aerobic glycolysis during tumorigenesis, but the underlying mechanisms are largely undefined. Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) is a transmembrane protein with potent cell signaling properties and has tumorigenic transformation property. Activation of NF-κB is a major signaling pathway mediating many downstream transformation properties of LMP1. Here we report that activation of mTORC1 by LMP1 is a key modulator for activation of NF-κB signaling to mediate aerobic glycolysis. NF-κB activation is involved in the LMP1-induced upregulation of glucose transporter 1 (Glut-1) transcription and growth of nasopharyngeal carcinoma (NPC) cells. Blocking the activity of mTORC1 signaling effectively suppressed LMP1-induced NF-κB activation and Glut-1 transcription. Interfering NF-κB signaling had no effect on mTORC1 activity but effectively altered Glut-1 transcription. Luciferase promoter assay of Glut-1 also confirmed that the Glut-1 gene is a direct target gene of NF-κB signaling. Furthermore, we demonstrated that C-terminal activating region 2 (CTAR2) of LMP1 is the key domain involved in mTORC1 activation, mainly through IKKβ-mediated phosphorylation of TSC2 at Ser939. Depletion of Glut-1 effectively led to suppression of aerobic glycolysis, inhibition of cell proliferation, colony formation, and attenuation of tumorigenic growth property of LMP1-expressing nasopharyngeal epithelial (NPE) cells. These findings suggest that targeting the signaling axis of mTORC1/NF-κB/Glut-1 represents a novel therapeutic target against NPC. IMPORTANCE Aerobic glycolysis is one of the hallmarks of cancer, including NPC. Recent studies suggest a role for LMP1 in mediating aerobic glycolysis. LMP1 expression is common in NPC. The delineation of essential signaling pathways induced by LMP1 in aerobic glycolysis contributes to the understanding of NPC pathogenesis. This study provides evidence that LMP1 upregulates Glut-1 transcription to control aerobic glycolysis and tumorigenic growth of NPC cells through mTORC1/NF-κB signaling. Our results reveal novel therapeutic targets against the mTORC1/NF-κB/Glut-1 signaling axis in the treatment of EBV-infected NPC. PMID:28053105

Diversity of thermophilic populations during thermophilic aerobic digestion of potato peel slurry.

PubMed

Ugwuanyi, J O; Harvey, L M; McNeil, B

2008-01-01

To study the diversity of thermophiles during thermophilic aerobic digestion (TAD) of agro-food waste slurries under conditions similar to full-scale processes. Population diversity and development in TAD were studied by standard microbiological techniques and the processes monitored by standard fermentation procedures. Facultative thermophiles were identified as Bacillus coagulans and B. licheniformis, while obligate thermophiles were identified as B. stearothermophilus. They developed rapidly to peaks of 10(7) to 10(8) in

Fate of four phthalate plasticizers under various wastewater treatment processes.

PubMed

Armstrong, Dana L; Rice, Clifford P; Ramirez, Mark; Torrents, Alba

2018-05-18

The fate of four phthalate plasticizers during wastewater treatment processes at six different wastewater treatment plants (WWTPs) was investigated. Concentrations of benzyl butyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DiNP), and diisodecyl phthalate (DiDP) were determined prior to either aerobic or anaerobic (conventional and advanced) treatment, after treatment, and in final, dewatered solids. Despite their elevated use worldwide, the fate of DiNP and DiDP during wastewater treatment have not been well characterized. DEHP was readily degraded during aerobic treatments while anaerobic digestion resulted in either no significant change in concentrations or an increase in concentration, in the case of more advanced anaerobic processes (thermal hydrolysis pretreatment and a two-phase acid/gas process). Impacts of the various treatment systems on DiNP, DiDP, and BBP concentrations were more varied - anaerobic digestion led to significant decreases, increases, or no significant change for these compounds, depending on the treatment facility, while aerobic treatment was generally effective at degrading the compounds. Additionally, thermal hydrolysis pretreatment of sludge prior to anaerobic digestion resulted in increases in DiNP, DiDP, and BBP concentrations. The predicted environmental concentrations for all four compounds in soils after a single biosolids application were calculated and the risk quotients for DEHP in soils were determined. The estimated toxicity risk for DEHP in soils treated with a single application of sludge from any of the six studied WWTPs is lower than the level of concern for acute and chronic risk, as defined by the US EPA.

The effects of manganese oxide octahedral molecular sieve chitosan microspheres on sludge bacterial community structures during sewage biological treatment

PubMed Central

Pan, Fei; Liu, Wen; Yu, Yang; Yin, Xianze; Wang, Qingrong; Zheng, Ziyan; Wu, Min; Zhao, Dongye; Zhang, Qiu; Lei, Xiaoman; Xia, Dongsheng

2016-01-01

This study examines the effects of manganese oxide octahedral molecular sieve chitosan microspheres (Fe3O4@OMS-2@CTS) on anaerobic and aerobic microbial communities during sewage biological treatment. The addition of Fe3O4@OMS-2@CTS (0.25 g/L) resulted in enhanced levels of operational performance for decolourization dye X-3B. However, degradation dye X-3B inhibition in the presence of Fe3O4@OMS-2@CTS was recorded as greater than or equal to 1.00 g/L. Illumina MiSeq high throughput sequencing of the 16 S rRNA gene showed that 108 genera were observed during the anaerobic process, while only 71 genera were observed during the aerobic process. The largest genera (Aequorivita) decreased from 21.14% to 12.65% and the Pseudomonas genera increased from 10.57% to 12.96% according to the abundance in the presence of 0.25 g/L Fe3O4@OMS-2@CTS during the anaerobic process. The largest Gemmatimonas genera decreased from 21.46% to 11.68% and the Isosphaerae genera increased from 5.8% to 11.98% according to the abundance in the presence of 0.25 g/L Fe3O4@OMS-2@CTS during the aerobic process. Moreover, the X-ray photoelectron spectroscopy results show that the valence states of Mn and Fe in Fe3O4@OMS-2@CTS changed during sewage biological treatment. PMID:27869226

Big Soda Lake (Nevada). 1. Pelagic bacterial heterotrophy and biomass

USGS Publications Warehouse

Zehr, Jon P.; Harvey, Ronald W.; Oremland, Ronald S.; Cloern, James E.; George, Leah H.; Lane, Judith L.

1987-01-01

Bacterial activities and abundance were measured seasonally in the water column of meromictic Big Soda Lake which is divided into three chemically distinct zones: aerobic mixolimnion, anaerobic mixolimnion, and anaerobic monimolimnion. Bacterial abundance ranged between 5 and 52 x 106 cells ml−1, with highest biomass at the interfaces between these zones: 2–4 mg C liter−1 in the photosynthetic bacterial layer (oxycline) and 0.8–2.0 mg C liter−1 in the chemocline. Bacterial cell size and morphology also varied with depth: small coccoid cells were dominant in the aerobic mixolimnion, whereas the monimolimnion had a more diverse population that included cocci, rods, and large filaments. Heterotrophic activity was measured by [methyl-3H]thymidine incorporation and [14C]glutamate uptake. Highest uptake rates were at or just below the photosynthetic bacterial layer and were attributable to small (<1 µm) heterotrophs rather than the larger photosynthetic bacteria. These high rates of heterotrophic uptake were apparently linked with fermentation; rates of other mineralization processes (e.g. sulfate reduction, methanogenesis, denitrification) in the anoxic mixolimnion were insignificant. Heterotrophic activity in the highly reduced monimolimnion was generally much lower than elsewhere in the water column. Therefore, although the monimolimnion contained most of the bacterial abundance and biomass (∼60%), most of the cells there were inactive.

Simultaneous Heterotrophic Nitrification and Aerobic Denitrification by Chryseobacterium sp. R31 Isolated from Abattoir Wastewater

PubMed Central

Kundu, Pradyut; Pramanik, Arnab; Dasgupta, Arpita; Mukherjee, Somnath; Mukherjee, Joydeep

2014-01-01

A heterotrophic carbon utilizing microbe (R31) capable of simultaneous nitrification and denitrification (SND) was isolated from wastewater of an Indian slaughterhouse. From an initial COD value of 583.0 mg/L, 95.54% was removed whilst, from a starting NH4 +-N concentration of 55.7 mg/L, 95.87% was removed after 48 h contact. The concentrations of the intermediates hydroxylamine, nitrite, and nitrate were low, thus ensuring nitrogen removal. Aerobic denitrification occurring during ammonium removal by R31 was confirmed by utilization of both nitrate and nitrite as nitrogen substrates. Glucose and succinate were superior while acetate and citrate were poor substrates for nitrogen removal. Molecular phylogenetic identification, supported by chemotaxonomic and physiological properties, assigned R31 as a close relative of Chryseobacterium haifense. The NH4 +-N utilization rate and growth of strain R31 were found to be higher at C/N = 10 in comparison to those achieved with C/N ratios of 5 and 20. Monod kinetic coefficients, half saturation concentration (K s), maximum rate of substrate utilization (k), yield coefficient, (Y) and endogenous decay coefficient (K d) indicated potential application of R31 in large-scale SND process. This is the first report on concomitant carbon oxidation, nitrification, and denitrification in the genus Chryseobacterium and the associated kinetic coefficients. PMID:24991552

The development of aerobic and skill assessment in soccer.

PubMed

O'Reilly, John; Wong, Stephen H S

2012-12-01

Methods of assessing soccer players' performance have developed significantly in recent times. The fitness profiles and skill levels of a prospective elite soccer player is a valuable resource for coaches in the process of identifying talent. Traditional means to measure aerobic fitness have centred on the 'aerobic capacity' or '&OV0312;O(2max)' test (also known as the maximal oxygen consumption test) but, over time, this has been shown not to be a sensitive measure for specific aspects of soccer in a match situation. Therefore, numerous soccer-specific simulations have been designed to re-create exercise patterns similar to those experienced during a match. Some of these studies have yet to be validated, while others have been shown to result in a similar physiological load to that encountered during regular match play. Further developments have led to specifically designed intermittent sprint tests, which are used as a sensitive tool to accurately measure the fluctuations in players' ability both between and within soccer seasons. Testing procedures have also been developed that incorporate elements of both skill and physical ability. Soccer-specific field tests have been designed, incorporating skill and dynamic movements, and this opens up the possibility of teams testing the aerobic capacity of their elite players using soccer-specific movements. Valid studies assessing soccer-specific skills in an ecologically sound environment have been quite rare until recently. Some test protocols have been deemed largely irrelevant to soccer match play, while others have had limited impact on scientific literature. More recently, skill tests have been developed and shown to be valid and reliable methods of assessing soccer skill performance. Many new skill tests continue to be developed, and some have been shown to be highly reliable, but further study of these relatively novel concepts is required before a more solid recommendation can be made. Overall, while significant work has been completed to date, there is still a need for further focused investigations, which can more closely assess the physiological demands of an elite soccer player, with a particular emphasis on sport-specific exercises during the execution of soccer skills. In this regard, more reliable and specific performance tests can be designed to more efficiently assess soccer players in the future.

Oxidation and ozonation of waste activated sludge.

PubMed

Mines, Richard O; Northenor, C Brett; Murchison, Mitchell

2008-05-01

In this bench-scale study, the treatment of waste activated sludge (WAS) was evaluated using aerobic digestion and ozonation. Two, 2-L batch digesters, one aerated and the other one ozonated, were operated for 30 days in each phase of the study. The aerated digester simulated the aerobic digestion process and served as control to the ozonated digester. In Phase I, the aerated digester was supplied 810 mg O(2) min(- 1), whereas, the ozonated digester was supplied 0.88 mg O(3) min(- 1). In Phase II, the oxygenation rate to the aerobic digester was increased to 1,200 mg O(2) min(- 1) while the ozonation rate was reduced to 0.44 mg O(3) min(- 1). Ozone was more effective than air at oxidizing and reducing both total solids (TS) and volatile solids (VS) in the WAS. TS removals of 50% and 56% were observed for the ozonated digester versus TS removals of 23% and 35% for the aerated digester. VS removals of 40% and 42% were observed for the aerobic digester versus 57% and 74% for the ozonated digester. Aerobic digestion barely met the 38% reduction in VS required by the U.S. Environmental Protection Agency (EPA). The degradation rate constant (K(d)) based on degradable TS for the ozonated digester varied from 0.082 to 0.11 days(- 1) and from 0.067 to 0.09 days(- 1) for the aerobic digester. Total chemical oxygen demand (TCOD) removal in the aerobic digester increased from 30% to 40% from Phase I to Phase II. TCOD removal increased slightly from 57% to 58% in the ozonated digester from Phase I to Phase II. Soluble chemical oxygen demand (SCOD) concentrations in the sludge supernatant increased with digestion time, especially in the ozonated digester. Approximately 0.12 to 0.22 mg SCOD was produced per mg of TS destroyed during ozonation. The specific oxygen uptake rate (SOUR) was consistently below the EPA standard of 1.5 mg O(2) per hr per g TS, indicating that the sludge was well stabilized. The average quantity of oxygen required during aerobic digestion was 1.53 g O(2) per g of TS destroyed. Actual ozone consumption rates were 0.57 mg O(3) per mg TS destroyed and 1.09 mg O(3) per mg TS destroyed for Phase II and Phase I, respectively.

Extracting aerobic system dynamics during unsupervised activities of daily living using wearable sensor machine learning models.

PubMed

Beltrame, Thomas; Amelard, Robert; Wong, Alexander; Hughson, Richard L

2018-02-01

Physical activity levels are related through algorithms to the energetic demand, with no information regarding the integrity of the multiple physiological systems involved in the energetic supply. Longitudinal analysis of the oxygen uptake (V̇o 2 ) by wearable sensors in realistic settings might permit development of a practical tool for the study of the longitudinal aerobic system dynamics (i.e., V̇o 2 kinetics). This study evaluated aerobic system dynamics based on predicted V̇o 2 data obtained from wearable sensors during unsupervised activities of daily living (μADL). Thirteen healthy men performed a laboratory-controlled moderate exercise protocol and were monitored for ≈6 h/day for 4 days (μADL data). Variables derived from hip accelerometer (ACC HIP ), heart rate monitor, and respiratory bands during μADL were extracted and processed by a validated random forest regression model to predict V̇o 2 . The aerobic system analysis was based on the frequency-domain analysis of ACC HIP and predicted V̇o 2 data obtained during μADL. Optimal samples for frequency domain analysis (constrained to ≤0.01 Hz) were selected when ACC HIP was higher than 0.05 g at a given frequency (i.e., participants were active). The temporal characteristics of predicted V̇o 2 data during μADL correlated with the temporal characteristics of measured V̇o 2 data during laboratory-controlled protocol ([Formula: see text] = 0.82, P < 0.001, n = 13). In conclusion, aerobic system dynamics can be investigated during unsupervised activities of daily living by wearable sensors. Although speculative, these algorithms have the potential to be incorporated into wearable systems for early detection of changes in health status in realistic environments by detecting changes in aerobic response dynamics. NEW & NOTEWORTHY The early detection of subclinical aerobic system impairments might be indicative of impaired physiological reserves that impact the capacity for physical activity. This study is the first to use wearable sensors in unsupervised activities of daily living in combination with novel machine learning algorithms to investigate the aerobic system dynamics with the potential to contribute to models of functional health status and guide future individualized health care in the normal population.

Effects of Aerobic Exercise on Mild Cognitive Impairment

PubMed Central

Baker, Laura D.; Frank, Laura L.; Foster-Schubert, Karen; Green, Pattie S.; Wilkinson, Charles W.; McTiernan, Anne; Plymate, Stephen R.; Fishel, Mark A.; Stennis Watson, G.; Cholerton, Brenna A.; Duncan, Glen E.; Mehta, Pankaj D.; Craft, Suzanne

2011-01-01

Objectives To examine the effects of aerobic exercise on cognition and other biomarkers associated with Alzheimer disease pathology for older adults with mild cognitive impairment, and assess the role of sex as a predictor of response. Design Six-month, randomized, controlled, clinical trial. Setting Veterans Affairs Puget Sound Health Care System clinical research unit. Participants Thirty-three adults (17 women) with amnestic mild cognitive impairment ranging in age from 55 to 85 years (mean age,70 years). Intervention Participants were randomized either to a high-intensity aerobic exercise or stretching control group. The aerobic group exercised under the supervision of a fitness trainer at 75% to 85% of heart rate reserve for 45 to 60 min/d, 4 d/wk for 6 months. The control group carried out supervised stretching activities according to the same schedule but maintained their heart rate at or below 50% of their heart rate reserve. Before and after the study, glucometabolic and treadmill tests were performed and fat distribution was assessed using dual-energy x-ray absorptiometry. At baseline, month 3, and month 6, blood was collected for assay and cognitive tests were administered. Main Outcome Measures Performance measures on Symbol-Digit Modalities, Verbal Fluency, Stroop, Trails B, Task Switching, Story Recall, and List Learning. Fasting plasma levels of insulin, cortisol, brain-derived neurotrophic factor, insulinlike growth factor-I, and β-amyloids 40 and 42. Results Six months of high-intensity aerobic exercise had sex-specific effects on cognition, glucose metabolism, and hypothalamic-pituitary-adrenal axis and trophic activity despite comparable gains in cardiorespiratory fitness and body fat reduction. For women, aerobic exercise improved performance on multiple tests of executive function, increased glucose disposal during the metabolic clamp, and reduced fasting plasma levels of insulin, cortisol, and brain-derived neurotrophic factor. For men, aerobic exercise increased plasma levels of insulinlike growth factor I and had a favorable effect only on Trails B performance. Conclusions This study provides support, using rigorous controlled methodology, for a potent nonpharma-cologic intervention that improves executive control processes for older women at high risk of cognitive decline. Moreover, our results suggest that a sex bias in cognitive response may relate to sex-based differences in glucometabolic and hypothalamic-pituitary-adrenal axis responses to aerobic exercise. PMID:20065132

Effects of aerobic exercise on mild cognitive impairment: a controlled trial.

PubMed

Baker, Laura D; Frank, Laura L; Foster-Schubert, Karen; Green, Pattie S; Wilkinson, Charles W; McTiernan, Anne; Plymate, Stephen R; Fishel, Mark A; Watson, G Stennis; Cholerton, Brenna A; Duncan, Glen E; Mehta, Pankaj D; Craft, Suzanne

2010-01-01

To examine the effects of aerobic exercise on cognition and other biomarkers associated with Alzheimer disease pathology for older adults with mild cognitive impairment, and assess the role of sex as a predictor of response. Six-month, randomized, controlled, clinical trial. Veterans Affairs Puget Sound Health Care System clinical research unit. Thirty-three adults (17 women) with amnestic mild cognitive impairment ranging in age from 55 to 85 years (mean age, 70 years). Intervention Participants were randomized either to a high-intensity aerobic exercise or stretching control group. The aerobic group exercised under the supervision of a fitness trainer at 75% to 85% of heart rate reserve for 45 to 60 min/d, 4 d/wk for 6 months. The control group carried out supervised stretching activities according to the same schedule but maintained their heart rate at or below 50% of their heart rate reserve. Before and after the study, glucometabolic and treadmill tests were performed and fat distribution was assessed using dual-energy x-ray absorptiometry. At baseline, month 3, and month 6, blood was collected for assay and cognitive tests were administered. Performance measures on Symbol-Digit Modalities, Verbal Fluency, Stroop, Trails B, Task Switching, Story Recall, and List Learning. Fasting plasma levels of insulin, cortisol, brain-derived neurotrophic factor, insulinlike growth factor-I, and beta-amyloids 40 and 42. Six months of high-intensity aerobic exercise had sex-specific effects on cognition, glucose metabolism, and hypothalamic-pituitary-adrenal axis and trophic activity despite comparable gains in cardiorespiratory fitness and body fat reduction. For women, aerobic exercise improved performance on multiple tests of executive function, increased glucose disposal during the metabolic clamp, and reduced fasting plasma levels of insulin, cortisol, and brain-derived neurotrophic factor. For men, aerobic exercise increased plasma levels of insulinlike growth factor I and had a favorable effect only on Trails B performance. This study provides support, using rigorous controlled methodology, for a potent nonpharmacologic intervention that improves executive control processes for older women at high risk of cognitive decline. Moreover, our results suggest that a sex bias in cognitive response may relate to sex-based differences in glucometabolic and hypothalamic-pituitary-adrenal axis responses to aerobic exercise.

Exercise and BMI z-score in Overweight and Obese Children and Adolescents: A Systematic Review and Network Meta-Analysis of Randomized Trials.

PubMed

Kelley, George A; Kelley, Kristi S; Pate, Russell R

2017-05-01

Examine the effects of selected types of exercise (aerobic, strength training, both) on BMI z-score in overweight and obese children and adolescents. Randomized exercise intervention trials ≥ 4 weeks were included. Studies were retrieved by searching six electronic databases, cross-referencing and expert review. Dual selection and abstraction occurred. Risk of bias and confidence in cumulative evidence were assessed. Network meta-analysis was performed using multivariate random-effects meta-regression models while surface under the cumulative ranking curves were used to calculate a hierarchy of exercise treatments. The number needed to treat (NNT) and percentile improvement (U 3 ) were also calculated. Thirty-four studies representing 2,239 participants were included. Median exercise occurred 3 times per week, 50 minutes per session over a 12-week period. Statistically significant reductions in BMI z-score were found for aerobic exercise and combined aerobic and strength exercise, but not strength training alone (M±SD, 95% CI: aerobic, -0.10, -0.15 to -0.05; aerobic and strength, -0.11, -0.19 to -0.03; strength, 0.04, -0.07 to 0.15). Combined aerobic and strength training was ranked best, followed by aerobic exercise and strength training. The NNT was 2 for both aerobic exercise and combined aerobic exercise and strength training. Percentile improvements were 28.8% for aerobic exercise and 31.5% for combined aerobic exercise and strength training. Confidence in effect estimates was ranked as low for aerobic exercise and very low for combined aerobic and strength training as well as strength training. Aerobic exercise and combined aerobic exercise and strength training are associated with reductions in BMI z-score. © 2016 Chinese Cochrane Center, West China Hospital of Sichuan University and John Wiley & Sons Australia, Ltd.

Exercise and BMI z-score in Overweight and Obese Children and Adolescents: A Systematic Review and Network Meta-Analysis of Randomized Trials

PubMed Central

George, Kelley; Kristi, Kelley; Russell, Pate

2017-01-01

Aim Examine the effects of selected types of exercise (aerobic, strength training, both) on BMI z-score in overweight and obese children and adolescents. Methods Randomized exercise intervention trials ≥ 4 weeks were included. Studies were retrieved by searching six electronic databases, cross-referencing and expert review. Dual selection and abstraction occurred. Risk of bias and confidence in cumulative evidence were assessed. Network meta-analysis was performed using multivariate random-effects meta-regression models while surface under the cumulative ranking curves were used to calculate a hierarchy of exercise treatments. The number needed to treat (NNT) and percentile improvement (U3) were also calculated. Results Thirty-four studies representing 2,239 participants were included. Median exercise occurred 3 times per week, 50 minutes per session over a 12-week period. Statistically significant reductions in BMI z-score were found for aerobic exercise and combined aerobic and strength exercise, but not strength training alone (M±SD, 95% CI: aerobic, -0.10, -0.15 to -0.05; aerobic and strength, -0.11, -0.19, -0.03; strength, 0.04, -0.07 to 0.15). Combined aerobic and strength training was ranked best, followed by aerobic exercise and strength training. The NNT was 2 for both aerobic exercise and combined aerobic exercise and strength training. Percentile improvements were 28.8% for aerobic exercise and 31.5% for combined aerobic exercise and strength training. Confidence in effect estimates was ranked as low for aerobic exercise and very low for combined aerobic and strength training as well as strength training. Conclusions Aerobic exercise and combined aerobic exercise and strength training are associated with reductions in BMI z-score. PMID:27792271

KEY CONCEPTS IN BIODEGRADATION

EPA Science Inventory

This one hour segment of the course identifies the biological processes that degrade petroleum hydrocarbons and MTBE. It reviews the stoichiometry of hydrocarbon degradation by aerobic respiration, nitrate reduction, sulfate reduction, iron (III) reduction, and methanogenesis. ...

Arsenic Speciation in Groundwater: Role of Thioanions

EPA Science Inventory

The behavior of arsenic in groundwater environments is fundamentally linked to its speciation. Understanding arsenic speciation is important because chemical speciation impacts reactivity, bioavailability, toxicity, and transport and fate processes. In aerobic environments arsen...

Teaching Aerobic Lifestyles: New Perspectives.

ERIC Educational Resources Information Center

Goodrick, G. Ken; Iammarino, Nicholas K.

1982-01-01

New approaches to teaching aerobic life-styles in secondary schools are suggested, focusing on three components: (1) the psychological benefits of aerobic activity; (2) alternative aerobic programs at nonschool locations; and (3) the development of an aerobics curriculum to help maintain an active life-style after graduation. (JN)

Temperature acclimation rate of aerobic scope and feeding metabolism in fishes: implications in a thermally extreme future

PubMed Central

Sandblom, Erik; Gräns, Albin; Axelsson, Michael; Seth, Henrik

2014-01-01

Temperature acclimation may offset the increased energy expenditure (standard metabolic rate, SMR) and reduced scope for activity (aerobic scope, AS) predicted to occur with local and global warming in fishes and other ectotherms. Yet, the time course and mechanisms of this process is little understood. Acclimation dynamics of SMR, maximum metabolic rate, AS and the specific dynamic action of feeding (SDA) were determined in shorthorn sculpin (Myoxocephalus scorpius) after transfer from 10°C to 16°C. SMR increased in the first week by 82% reducing AS to 55% of initial values, while peak postprandial metabolism was initially greater. This meant that the estimated AS during peak SDA approached zero, constraining digestion and leaving little room for additional aerobic processes. After eight weeks at 16°C, SMR was restored, while AS and the estimated AS during peak SDA recovered partly. Collectively, this demonstrated a considerable capacity for metabolic thermal compensation, which should be better incorporated into future models on organismal responses to climate change. A mathematical model based on the empirical data suggested that phenotypes with fast acclimation rates may be favoured by natural selection as the accumulated energetic cost of a slow acclimation rate increases in a warmer future with exacerbated thermal variations. PMID:25232133

[Phylogenetic analysis and nitrogen removal characteristics of a heterotrophic nitrifying-aerobic denitrifying bacteria strain from marine environment].

PubMed

Sun, Xuemei; Li, Qiufen; Zhang, Yan; Liu, Huaide; Zhao, Jun; Qu, Keming

2012-06-04

We determined the phylogenetic position of a heterotrophic nitrifying-aerobic denitrifying bacterium X3, and detected its nitrogen removal characteristics for providing evidence to explain the principle of heterotrophic nitrification-aerobic denitrification and to improve the process in purification of marine-culture wastewater. The evolutionary position of the strain was determined based on its morphological, physiological, biochemical characteristics and 16SrRNA gene sequence. The nitrification-denitrification ability of this strain was detected by detecting its nitrogen removal efficiency and growth on different inorganic nitrogen source. Strain X3 was identified as Halomonas sp. It grew optimally at salinity 3%, pH 8.5, C:N 10:1 at 28 degrees C, and it could still survive at 15% salinity. The removal of NH4+ -N, NO2(-) -N and NO3(-) -N was 98.29%, 99.07%, 96.48% respectively within 24 h. When three inorganic nitrogen existed simultaneously, it always utilized ammonia firstly, and the total inorganic nitrogen removal was higher than with only one nitrogen, suggesting that strain X3 has the ability of simultaneous nitrification and denitrification and completing the whole nitrogen removing process. Strain X3 belonged to the genus of Halomonas. It had strong simultaneous nitrification and denitrification capability and could live in high-salinity environment.

Mitochondrial origin of extracelullar transferred electrons in yeast-based biofuel cells.

PubMed

Hubenova, Yolina; Mitov, Mario

2015-12-01

The influence of mitochondrial electron transport chain inhibitors on the electricity outputs of Candida melibiosica yeast-based biofuel cell was investigated. The addition of 30 μM rotenone or antimycin A to the yeast suspension results in a decrease in the current generation, corresponding to 25.7±1.3%, respectively 38.8±1.9% reduction in the electric charge passed through the bioelectrochemical system. The latter percentage coincides with the share of aerobic respiration in the yeast catabolic processes, determined by the decrease of the ethanol production during cultivation in the presence of oxygen compared with that obtained under strict anaerobic conditions. It was established that the presence of both inhibitors leads to almost complete mitochondrial dysfunction, expressed by inactivation of cytochrome c oxidase and NADH:ubiquinone oxidoreductase as well as reduced electrochemical activity of isolated yeast mitochondria. It was also found that methylene blue partially neutralized the rotenone poisoning, probably serving as alternative intracellular electron shuttle for by-passing the complex I blockage. Based on the obtained results, we suppose that electrons generated through the aerobic respiration processes in the mitochondria participate in the extracellular electron transfer from the yeast cells to the biofuel cell anode, which contributes to higher current outputs at aerobic conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

Degradation of typical N-nitrosodimethylamine (NDMA) precursors and its formation potential in anoxic-aerobic (AO) activated sludge system.

PubMed

Wang, Lin; Li, Yongmei; He, Guodong

2014-01-01

N-nitrosodimethylamine (NDMA) is an emerging disinfection byproduct. Removal of its potential precursors is considered as an effective method to control NDMA. In this study, four typical NDMA precursors (dimethylamine (DMA), trimethylamine (TMA), dimethylformamide (DMFA) and dimethylaminobenzene (DMAB)) were selected, and their removal capacities by activated sludge were investigated. Batch experiments indicated that removal of NDMA precursors was better under aerobic condition than anoxic condition; and their specific degradation rates follow the order of DMA > TMA > DMFA > DMAB. In anoxic-aerobic (AO) activated sludge system, the optimal hydraulic retention time and sludge retention time were 10 h and 20 d, respectively, for the removal of both NDMA precursors (four selected NDMA precursors and NDMA formation potential (NDMA FP)) and nutrients. Our results also suggested that there was a positive correlation between NDMA FP and dissolved organic nitrogen (DON) in wastewater. The removal efficiency of NDMA FP was in the range of 46.8-72.5% in the four surveyed wastewater treatment plants except the one which adopted chemically enhanced primary process. The results revealed that the AO system had the advantage of removing NDMA FP. Our results are helpful for the knowledge of the removals of NDMA precursors during activated sludge treatment processes.

Limitations of Thioglycolate Broth as a Sterility Test Medium for Materials Exposed to Gaseous Ethylene Oxide1

PubMed Central

Doyle, John E.; Mehrhof, William H.; Ernst, Robert R.

1968-01-01

Although ethylene oxide is a reliable sterilizer, the process may be limited by diffusion. Thus, situations may exist where microorganisms are protected from the sterilizing gas. It is possible that the exterior of a substance may be sterilized, whereas the interior is not. We investigated three general types of materials in which this limitation of diffusion could occur: the bore of glass and plastic tubing, the center of cotton balls, and plastic adhesive film/paper backing interface. These materials were contaminated as close to their geometric center as possible with Bacillus subtilis var. niger spores occluded in crystals of sodium chloride. After exposure of the contaminated materials (except aluminum foil) to ethylene oxide, thioglycolate broth (a standard sterility-test medium) indicated sterility, whereas Trypticase Soy Broth indicated nonsterility. It is likewise possible that aerobic microorganisms, surviving in or on material after exposure to dry heat or steam sterilization processes, would not be recovered by thioglycollate broth. Entrapped aerobic organisms will probably not grow out in the low oxygen tension zone of an anaerobic medium such as thioglycollate broth. It is recommended than an aerobic medium such as Trypticase Soy Broth be used concurrently with thioglycolate broth for sterility testing. PMID:4973064

Effect of fire residues (ash and char) on microbial activity, respiration and methanogenesis in three subtropical wetland soils

NASA Astrophysics Data System (ADS)

Medvedeff, C.; Hogue, B.; Inglett, P.

2011-12-01

Prescribed fire is a common restoration and maintenance technique in the southern United States. Prescribed burns coupled with frequent natural fires in South Florida can have devastating effects on ecosystem function. To determine the effect fire residues have on carbon biogeochemical cycling litter material was obtained from two restored and one native marl wetland in Everglades National Park and manipulated in a laboratory setting to produce ash and vegetation derived char. Based on vegetation biomass removal pre and post fire (insitu) appropriate aliquots of each fire residue was added to experimental microcosms as a soil amendment. Soil enzymes (β-glucosidase, cellobiohydrolase, phosphatase, bis-phosphate and leucine amino peptidase), aerobic and anaerobic respiration (CO2) potentials, extractable C and methanogenesis were measured over a 25 day period. Regardless of site C enzymes responded to both amendments within 5 days of addition. Similarly amended soil contained more extractable carbon in the reference and one of the restored sites. In the restored sites ash and char inhibited methanogenesis, had no effect on anaerobic CO2 potentials, but stimulated aerobic respiration after ten days. In contrast, within the first ten days phosphatase enzyme activity was lower in the ash treatment when compared to the control treatment and stimulation of aerobic respiration was observed in both treatment soils. After ten days ash stimulated methanogenic processing while suppressing anaerobic CO2 production suggesting methanogens in this ecosystem may be dependant on usable carbon substrates derived from aerobic microbial processing. This study illustrates the variable response of C parameters to complete and incomplete combusted materials produced from both prescribed and natural fires with particular importance to fire adapted ecosystems.

Reducing the startup time of aerobic granular sludge reactors through seeding floccular sludge with crushed aerobic granules.

PubMed

Pijuan, Maite; Werner, Ursula; Yuan, Zhiguo

2011-10-15

One of the main challenging issues for the aerobic granular sludge technology is the long startup time when dealing with real wastewaters. This study presents a novel strategy to reduce the time required for granulation while ensuring a high level of nutrient removal. This new approach consists of seeding the reactor with a mixture of crushed aerobic granules and floccular sludge. The effectiveness of the strategy was demonstrated using abattoir wastewater, containing nitrogen and phosphorus at approximately 250 mgN/L and 30 mgP/L, respectively. Seven different mixtures of crushed granules and floccular sludge at granular sludge fractions (w/w in dry mass) of 0%, 5%, 10%, 15%, 25%, 30% and 50% were used to start eight granulation processes. The granulation time (defined as the time when the 10th percentile bacterial aggregate size is larger than 200 μm) displayed a strong dependency on the fraction of granular sludge. The shortest granulation time of 18 days was obtained with 50% crushed granules, in comparison with 133 days with 5% crushed granules. Full granulation was not achieved in the two trials without seeding with crushed granules. In contrast to the 100% floccular sludge cases, where a substantial loss of biomass occurred during granulation, the biomass concentration in all other trails did not decrease during granulation. This allowed that good nitrogen removal was maintained in all the reactors during the granulation process. However, enhanced biological phosphorus removal was achieved in only one of the eight trials. This was likely due to the temporary accumulation of nitrite, a strong inhibitor of polyphosphate accumulating organisms. Copyright © 2011 Elsevier Ltd. All rights reserved.

Microbial community functional structure in response to micro-aerobic conditions in sulfate-reducing sulfur-producing bioreactor.

PubMed

Yu, Hao; Chen, Chuan; Ma, Jincai; Xu, Xijun; Fan, Ronggui; Wang, Aijie

2014-05-01

Limited oxygen supply to anaerobic wastewater treatment systems had been demonstrated as an effective strategy to improve elemental sulfur (S(0)) recovery, coupling sulfate reduction and sulfide oxidation. However, little is known about the impact of dissolved oxygen (DO) on the microbial functional structures in these systems. We used a high throughput tool (GeoChip) to evaluate the microbial community structures in a biological desulfurization reactor under micro-aerobic conditions (DO: 0.02-0.33 mg/L). The results indicated that the microbial community functional compositions and structures were dramatically altered with elevated DO levels. The abundances of dsrA/B genes involved in sulfate reduction processes significantly decreased (p < 0.05, LSD test) at relatively high DO concentration (DO: 0.33 mg/L). The abundances of sox and fccA/B genes involved in sulfur/sulfide oxidation processes significantly increased (p < 0.05, LSD test) in low DO concentration conditions (DO: 0.09 mg/L) and then gradually decreased with continuously elevated DO levels. Their abundances coincided with the change of sulfate removal efficiencies and elemental sulfur (S(0)) conversion efficiencies in the bioreactor. In addition, the abundance of carbon degradation genes increased with the raising of DO levels, showing that the heterotrophic microorganisms (e.g., fermentative microorganisms) were thriving under micro-aerobic condition. This study provides new insights into the impacts of micro-aerobic conditions on the microbial functional structure of sulfate-reducing sulfur-producing bioreactors, and revealed the potential linkage between functional microbial communities and reactor performance. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

The Frequency-Dependent Aerobic Exercise Effects of Hypothalamic GABAergic Expression and Cardiovascular Functions in Aged Rats

PubMed Central

Li, Yan; Zhao, Ziqi; Cai, Jiajia; Gu, Boya; Lv, Yuanyuan; Zhao, Li

2017-01-01

A decline in cardiovascular modulation is a feature of the normal aging process and associated with cardiovascular diseases (CVDs) such as hypertension and stroke. Exercise training is known to promote cardiovascular adaptation in young animals and positive effects on motor and cognitive capabilities, as well as on brain plasticity for all ages in mice. Here, we examine the question of whether aerobic exercise interventions may impact the GABAergic neurons of the paraventricular nucleus (PVN) in aged rats which have been observed to have a decline in cardiovascular integration function. In the present study, young (2 months) and old (24 months) male Wistar rats were divided into young control (YC), old sedentary, old low frequency exercise (20 m/min, 60 min/day, 3 days/week, 12 weeks) and old high frequency exercise (20 m/min, 60 min/day, 5 days/week, 12 weeks). Exercise training indexes were obtained, including resting heart rate (HR), blood pressure (BP), plasma norepinephrine (NE), and heart weight (HW)-to-body weight (BW) ratios. The brain was removed and processed according to the immunofluorescence staining and western blot used to analyze the GABAergic terminal density, the proteins of GAD67, GABAA receptor and gephyrin in the PVN. There were significant changes in aged rats compared with those in the YC. Twelve weeks aerobic exercise training has volume-dependent ameliorated effects on cardiovascular parameters, autonomic nervous activities and GABAergic system functions. These data suggest that the density of GABAergic declines in the PVN is associated with imbalance in autonomic nervous activities in normal aging. Additionally, aerobic exercise can rescue aging-related an overactivity of the sympathetic nervous system and induces modifications the resting BP and HR to lower values via improving the GABAergic system in the PVN. PMID:28713263

Combined mesophilic anaerobic and thermophilic aerobic digestion process for high-strength food wastewater to increase removal efficiency and reduce sludge discharge.

PubMed

Jang, H M; Park, S K; Ha, J H; Park, J M

2014-01-01

In this study, a process that combines the mesophilic anaerobic digestion (MAD) process with thermophilic aerobic digestion (TAD) for high-strength food wastewater (FWW) treatment was developed to examine the removal of organic matter and methane production. All effluent discharged from the MAD process was separated into solid and liquid portions. The liquid part was discarded and the sludge part was passed to the TAD process for further degradation. Then, the digested sludge from the TAD process was recycled back to the MAD unit to achieve low sludge discharge from the combined process. The reactor combination was operated in two phases: during Phase I, 40 d of total hydraulic retention time (HRT) was applied; during Phase II, 20 d was applied. HRT of the TAD process was fixed at 5 d. For a comparison, a control process (single-stage MAD) was operated with the same HRTs of the combined process. Our results indicated that the combined process showed over 90% total solids, volatile solids and chemical oxygen demand removal efficiencies. In addition, the combined process showed a significantly higher methane production rate than that of the control process. Consequently, the experimental data demonstrated that the combined MAD-TAD process was successfully employed for high-strength FWW treatment with highly efficient organic matter reduction and methane production.

Examining physiotherapist use of structured aerobic exercise testing to decrease barriers to aerobic exercise.

PubMed

Foster B Sc, Evan; Fraser, Julia E; Inness PhD, Elizabeth L; Munce, Sarah; Biasin, Louis; Poon, Vivien; Bayley, Mark

2018-04-03

To determine the frequency of physiotherapist-administered aerobic exercise testing/training, the proportion of physiotherapists who administer this testing/training, and the barriers that currently exist across different practice environments. A secondary objective is to identify the learning needs of physiotherapists for the development of an education curriculum in aerobic exercise testing and training with electrocardiograph (ECG) administration and interpretation. National, cross-sectional survey. Registered physiotherapists practicing in Canada. Out of 137 participants, most (75%) physiotherapists prescribed aerobic exercise on a regular basis (weekly); however, 65% had never conducted an aerobic exercise test. There were no significant differences in frequency of aerobic exercise testing across different practice environments or across years of physiotherapy experience. Physiotherapists perceived the main barriers to aerobic exercise testing as being a lack of equipment/space (78%), time (65%), and knowledge (56%). Although most (82%) were uncomfortable administering 12-lead ECG-monitored aerobic exercise tests, 60% stated they would be interested in learning more about ECG interpretation. This study found that physiotherapists are regularly implementing aerobic exercise. This exercise was infrequently guided by formal aerobic exercise testing, which could increase access to safe and effective exercise within the optimal aerobic training zone. As well, this could facilitate training in patients with cardiovascular diagnoses that require additional testing for medical clearance. Increased ECG training and access to equipment for physiotherapists may augment pre-screening aerobic exercise testing. This training should include learning the key arrhythmias for aerobic exercise test termination as defined by the American College of Sports Medicine.

Physical fitness in children with haemophilia and the effect of overweight.

PubMed

Douma-van Riet, D C M; Engelbert, R H H; van Genderen, Frank R; Ter Horst-De Ronde, Manon T M; de Goede-Bolder, Arja; Hartman, Annelies

2009-03-01

Although children with haemophilia are advised to participate in physical activities, their physical fitness has not been studied in a large group. In addition, children with haemophilia may be at increased risk for becoming overweight as a result of inactivity because of joint bleedings or because of overprotection. This study aimed to assess physical fitness (aerobic capacity), joint status, muscle strength, quality of life (QoL), self-reported motor competence and also prevalence of overweight and its association with physical parameters. Weight and height were measured. Skin folds were measured unilaterally at biceps, triceps, subscapular and supra-iliac sites. Aerobic capacity was determined on a cycle ergometer or with a 6-min walk test (6MWT). Muscle strength and active range of motion of elbows, knees and ankle joints were measured. Self-reported motor competence was measured with the 'Competentie BelevingsSchaal voor Kinderen'. Joint pain was scored on a Visual Analogue Scale. The Haemo-QoL Index was used to measure QoL. In 158 Dutch boys with haemophilia, with a mean age of 12.7 years (SD 2.9), normal aerobic capacity and muscle strength were found. Joint pain was reported by 16% of the participants. The prevalence of overweight (16%) was slightly increased when compared with healthy Dutch boys (13.5%). Being overweight had a negative association with the6MWT and QoL. Dutch children with haemophilia have normal aerobic exercise capacity and muscle strength. The majority also has normal joint mobility. Prevalence of overweight is slightly increased.

Production of PFOS from aerobic soil biotransformation of two perfluoroalkyl sulfonamide derivatives.

PubMed

Mejia Avendaño, Sandra; Liu, Jinxia

2015-01-01

The continuous production and use in certain parts of the world of perfluoroalkyl sulfonamide derivatives that can degrade to perfluorooctane sulfonic acid (PFOS) has called for better understanding of the environmental fate of these PFOS precursors. Aerobic soil biotransformation of N-ethyl perfluorooctane sulfonamide (EtFOSA, also known as Sulfluramid) was quantitatively investigated in semi-closed soil microcosms over 182 d for the first time. The apparent soil half-life of EtFOSA was 13.9±2.1 d and the yield to PFOS by the end of incubation was 4.0 mol%. A positive identification of a previously suspected degradation product, EtFOSA alcohol, provided strong evidence to determine degradation pathways. The lower mass balance in sterile soil than live soil suggested likely strong irreversible sorption of EtFOSA to the test soil. The aerobic soil biotransformation of a technical grade N-ethyl perfluorooctane sulfonamidoethanol (EtFOSE) was semi-quantitatively examined, and the degradation pathways largely followed those in activated sludge and marine sediments. Aside from PFOS, major degradation products included N-Ethyl perfluorooctane sulfonamidoacetic acid (EtFOSAA), perfluorooctane sulfonamide (FOSA) and perfluorooctane sulfonamide acetic acid (FOSAA). This study confirms that aerobic soil biotransformation of EtFOSE and EtFOSA contributes significantly to the PFOS observed in soil environment, as well as to several highly persistent sulfonamide derivatives frequently detected in biosolid-amended soils and landfill leachates. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nitric Oxide Accumulation: The Evolutionary Trigger for Phytopathogenesis

PubMed Central

Santana, Margarida M.; Gonzalez, Juan M.; Cruz, Cristina

2017-01-01

Many publications highlight the importance of nitric oxide (NO) in plant–bacteria interactions, either in the promotion of health and plant growth or in pathogenesis. However, the role of NO in the signaling between bacteria and plants and in the fate of their interaction, as well as the reconstruction of their interactive evolution, remains largely unknown. Despite the complexity of the evolution of life on Earth, we explore the hypothesis that denitrification and aerobic respiration were responsible for local NO accumulation, which triggered primordial antagonistic biotic interactions, namely the first phytopathogenic interactions. N-oxides, including NO, could globally accumulate via lightning synthesis in the early anoxic ocean and constitute pools for the evolution of denitrification, considered an early step of the biological nitrogen cycle. Interestingly, a common evolution may be proposed for components of denitrification and aerobic respiration pathways, namely for NO and oxygen reductases, a theory compatible with the presence of low amounts of oxygen before the great oxygenation event (GOE), which was generated by Cyanobacteria. During GOE, the increase in oxygen caused the decrease of Earth’s temperature and the consequent increase of oxygen dissolution and availability, making aerobic respiration an increasingly dominant trait of the expanding mesophilic lifestyle. Horizontal gene transfer was certainly important in the joint expansion of mesophily and aerobic respiration. First denitrification steps lead to NO formation through nitrite reductase activity, and NO may further accumulate when oxygen binds NO reductase, resulting in denitrification blockage. The consequent transient NO surplus in an oxic niche could have been a key factor for a successful outcome of an early denitrifying prokaryote able to scavenge oxygen by NO/oxygen reductase or by an independent heterotrophic aerobic respiration pathway. In fact, NO surplus could result in toxicity causing “the first disease” in oxygen-producing Cyanobacteria. We inspected in bacteria the presence of sequences similar to the NO-producing nitrite reductase nirS gene of Thermus thermophilus, an extreme thermophilic aerobe of the Thermus/Deinococcus group, which constitutes an ancient lineage related to Cyanobacteria. In silico analysis revealed the relationship between the presence of nirS genes and phytopathogenicity in Gram-negative bacteria. PMID:29067010

Effective pine bark composting with the Dome Aeration Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trois, Cristina; Polster, Andreas

2007-07-01

In South Africa garden refuse is primarily disposed of in domestic landfills. Due to the large quantities generated, any form of treatment would be beneficial for volume reduction, waste stabilization and resource recovery. Dome Aeration Technology (DAT) is an advanced process for aerobic biological degradation of garden refuse and general waste [Paar, S., Brummack, J., Gemende, B., 1999a. Advantages of dome aeration in mechanical-biological waste treatment. In: Proceedings of the 7th International Waste Management and Landfill Symposium, Cagliari, 4-8 October 1999; Paar, S., Brummack, J., Gemende, B., 1999b. Mechanical-biological waste stabilization by the dome aeration method. Environment Protection Engineering 25more » (3/99). Mollekopf, N., Brummack, J., Paar, S., Vorster, K., 2002. Use of the Dome Aeration Technology for biochemical stabilization of waste prior to landfilling. In: Proceedings of the Wastecon 2002, Waste Congress and Exhibition, Durban, South Africa.]. It is a non-reactor open windrow composting process, with the main advantage being that the input material needs no periodic turning. A rotting time of only 3-4 months indicates the high efficiency. Additionally, the low capital/operational costs, low energy inputs and limited plant requirements provide potential for use in aerobic refuse stabilization. The innovation in the DAT process is the passive aeration achieved by thermally driven advection through open windrows caused by temperature differences between the degrading material and the outside environment. This paper investigates the application of Dome Aeration Technology to pine bark composting as part of an integrated waste management strategy. A full-scale field experiment was performed at the Bisasar Road Landfill Site in Durban to assess the influence of climate, waste composition and operational conditions on the process. A test windrow was constructed and measurements of temperature and airflow through the material were taken. The process monitoring revealed that prevailing climatic conditions in a subtropical location do not affect the high efficiency of this technology. However, the composition of the input material can be detrimental for production of high quality compost because of a lack of nitrate.« less

Sustainable multistage process for enhanced productivity of bioplastics from waste remediation through aerobic dynamic feeding strategy: Process integration for up-scaling.

PubMed

Amulya, K; Jukuri, Srinivas; Venkata Mohan, S

2015-01-01

Polyhydroxyalkanoates (PHA) production was evaluated in a multistage operation using food waste as a renewable feedstock. The first step involved the production of bio-hydrogen (bio-H2) via acidogenic fermentation. Volatile fatty acid (VFA) rich effluent from bio-H2 reactor was subsequently used for PHA production, which was carried out in two stages, Stage II (culture enrichment) and Stage III (PHA production). PHA-storing microorganisms were enriched in a sequencing batch reactor (SBR), operated at two different cycle lengths (CL-24; CL-12). Higher polymer recovery as well as VFA removal was achieved in CL-12 operation both in Stage II (16.3% dry cell weight (DCW); VFA removal, 84%) and Stage III (23.7% DCW; VFA removal, 88%). The PHA obtained was a co-polymer [P(3HB-co-3HV)] of PHB and PHV. The results obtained indicate that this integrated multistage process offers new opportunities to further leverage large scale PHA production with simultaneous waste remediation in the framework of biorefinery. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evolution of cytochrome oxidase, an enzyme older than atmospheric oxygen.

PubMed

Castresana, J; Lübben, M; Saraste, M; Higgins, D G

1994-06-01

Cytochrome oxidase is a key enzyme in aerobic metabolism. All the recorded eubacterial (domain Bacteria) and archaebacterial (Archaea) sequences of subunits 1 and 2 of this protein complex have been used for a comprehensive evolutionary analysis. The phylogenetic trees reveal several processes of gene duplication. Some of these are ancient, having occurred in the common ancestor of Bacteria and Archaea, whereas others have occurred in specific lines of Bacteria. We show that eubacterial quinol oxidase was derived from cytochrome c oxidase in Gram-positive bacteria and that archaebacterial quinol oxidase has an independent origin. A considerable amount of evidence suggests that Proteobacteria (Purple bacteria) acquired quinol oxidase through a lateral gene transfer from Gram-positive bacteria. The prevalent hypothesis that aerobic metabolism arose several times in evolution after oxygenic photosynthesis, is not sustained by two aspects of the molecular data. First, cytochrome oxidase was present in the common ancestor of Archaea and Bacteria whereas oxygenic photosynthesis appeared in Bacteria. Second, an extant cytochrome oxidase in nitrogen-fixing bacteria shows that aerobic metabolism is possible in an environment with a very low level of oxygen, such as the root nodules of leguminous plants. Therefore, we propose that aerobic metabolism in organisms with cytochrome oxidase has a monophyletic and ancient origin, prior to the appearance of eubacterial oxygenic photosynthetic organisms.

MAP training: combining meditation and aerobic exercise reduces depression and rumination while enhancing synchronized brain activity

PubMed Central

Alderman, B L; Olson, R L; Brush, C J; Shors, T J

2016-01-01

Mental and physical (MAP) training is a novel clinical intervention that combines mental training through meditation and physical training through aerobic exercise. The intervention was translated from neuroscientific studies indicating that MAP training increases neurogenesis in the adult brain. Each session consisted of 30 min of focused-attention (FA) meditation and 30 min of moderate-intensity aerobic exercise. Fifty-two participants completed the 8-week intervention, which consisted of two sessions per week. Following the intervention, individuals with major depressive disorder (MDD; n=22) reported significantly less depressive symptoms and ruminative thoughts. Typical healthy individuals (n=30) also reported less depressive symptoms at follow-up. Behavioral and event-related potential indices of cognitive control were collected at baseline and follow-up during a modified flanker task. Following MAP training, N2 and P3 component amplitudes increased relative to baseline, especially among individuals with MDD. These data indicate enhanced neural responses during the detection and resolution of conflicting stimuli. Although previous research has supported the individual beneficial effects of aerobic exercise and meditation for depression, these findings indicate that a combination of the two may be particularly effective in increasing cognitive control processes and decreasing ruminative thought patterns. PMID:26836414

Biodegradation of methyl t-butyl ether by aerobic granules under a cosubstrate condition.

PubMed

Zhang, L L; Chen, J M; Fang, F

2008-03-01

Aerobic granules efficient at degrading methyl tert-butyl ether (MTBE) with ethanol as a cosubstrate were successfully developed in a well-mixed sequencing batch reactor (SBR). Aerobic granules were first observed about 100 days after reactor startup. Treatment efficiency of MTBE in the reactor during stable operation exceeded 99.9%, and effluent MTBE was in the range of 15-50 microg/L. The specific MTBE degradation rate was observed to increase with increasing MTBE initial concentration from 25 to 500 mg/L, which peaked at 22.7 mg MTBE/g (volatile suspended solids).h and declined with further increases in MTBE concentration as substrate inhibition effects became significant. Microbial-community deoxyribonucleic acid profiling was carried out using denaturing gradient gel electrophoresis of polymerase chain reaction-amplified 16S ribosomal ribonucleic acid. The reactor was found to be inhabited by several diverse bacterial species, most notably microorganisms related to the genera Sphingomonas, Methylobacterium, and Hyphomicrobium vulgare. These organisms were previously reported to be associated with MTBE biodegradation. A majority of the bands in the reactor represented a group of organisms belonging to the Flavobacteria-Proteobacteria-Actinobacteridae class of bacteria. This study demonstrates that MTBE can be effectively degraded by aerobic granules under a cosubstrate condition and gives insight into the microorganisms potentially involved in the process.

Characterization of efficient aerobic denitrifiers isolated from two different sequencing batch reactors by 16S-rRNA analysis.

PubMed

Wang, Ping; Li, Xiuting; Xiang, Mufei; Zhai, Qian

2007-06-01

By adopting two sequencing batch reactors (SBRs) A and B, nitrate as the substrate, and the intermittent aeration mode, activated sludge was domesticated to enrich aerobic denitrifiers. The pHs of reactor A were approximately 6.3 at DOs 2.2-6.1 mg/l for a carbon source of 720 mg/l COD; the pHs of reactor B were 6.8-7.8 at DOs 2.2-3.0 mg/l for a carbon source of 1500 mg/l COD. Both reactors maintained an influent nitrate concentration of 80 mg/l NO3- -N. When the total inorganic nitrogen (TIN) removal efficiency of both reactors reached 60%, aerobic denitrifier accumulation was regarded completed. By bromthymol blue (BTB) medium, 20 bacteria were isolated from the two SBRs and DNA samples of 8 of these 20 strains were amplified by PCR and processed for 16SrRNA sequencing. The obtained results were analysed by a Blast similarity search of the GenBank database, and constructing a phylogenetic tree for identification by comparison. The 8 bacteria were found to belong to the genera Pseudomonas, Delftia, Herbaspirillum and Comamonas. At present, no Delftia has been reported to be an aerobic denitrifier.

Light-Dependent Aerobic Methane Oxidation Reduces Methane Emissions from Seasonally Stratified Lakes

PubMed Central

Oswald, Kirsten; Milucka, Jana; Brand, Andreas; Littmann, Sten; Wehrli, Bernhard; Kuypers, Marcel M. M.; Schubert, Carsten J.

2015-01-01

Lakes are a natural source of methane to the atmosphere and contribute significantly to total emissions compared to the oceans. Controls on methane emissions from lake surfaces, particularly biotic processes within anoxic hypolimnia, are only partially understood. Here we investigated biological methane oxidation in the water column of the seasonally stratified Lake Rotsee. A zone of methane oxidation extending from the oxic/anoxic interface into anoxic waters was identified by chemical profiling of oxygen, methane and δ13C of methane. Incubation experiments with 13C-methane yielded highest oxidation rates within the oxycline, and comparable rates were measured in anoxic waters. Despite predominantly anoxic conditions within the zone of methane oxidation, known groups of anaerobic methanotrophic archaea were conspicuously absent. Instead, aerobic gammaproteobacterial methanotrophs were identified as the active methane oxidizers. In addition, continuous oxidation and maximum rates always occurred under light conditions. These findings, along with the detection of chlorophyll a, suggest that aerobic methane oxidation is tightly coupled to light-dependent photosynthetic oxygen production both at the oxycline and in the anoxic bottom layer. It is likely that this interaction between oxygenic phototrophs and aerobic methanotrophs represents a widespread mechanism by which methane is oxidized in lake water, thus diminishing its release into the atmosphere. PMID:26193458

Association of physical fitness and fatness with cognitive function in women with fibromyalgia.

PubMed

Soriano-Maldonado, Alberto; Artero, Enrique G; Segura-Jiménez, Víctor; Aparicio, Virgina A; Estévez-López, Fernando; Álvarez-Gallardo, Inmaculada C; Munguía-Izquierdo, Diego; Casimiro-Andújar, Antonio J; Delgado-Fernández, Manuel; Ortega, Francisco B

2016-09-01

This study assessed the association of fitness and fatness with cognitive function in women with fibromyalgia, and the independent influence of their single components on cognitive tasks. A total of 468 women with fibromyalgia were included. Speed of information processing and working memory (Paced Auditory Serial Addition Task), as well as immediate and delayed recall, verbal learning and delayed recognition (Rey Auditory Verbal Learning Test) were assessed. Aerobic fitness, muscle strength, flexibility and motor agility were assessed with the Senior Fitness Test battery. Body mass index, percent body fat, fat-mass index and waist circumference were measured. Aerobic fitness was associated with attention and working memory (all, p < 0.05). All fitness components were generally associated with delayed recall, verbal learning and delayed recognition (all, p < 0.05). Aerobic fitness showed the most powerful association with attention, working memory, delayed recall and verbal learning, while motor agility was the most powerful indicator of delayed recognition. None of the fatness parameters were associated with any of the outcomes (all, p > 0.05). Our results suggest that fitness, but not fatness, is associated with cognitive function in women with fibromyalgia. Aerobic fitness appears to be the most powerful fitness component regarding the cognitive tasks evaluated.

Evaluation of energy consumption during aerobic sewage sludge treatment in dairy wastewater treatment plant.

PubMed

Dąbrowski, Wojciech; Żyłka, Radosław; Malinowski, Paweł

2017-02-01

The subject of the research conducted in an operating dairy wastewater treatment plant (WWTP) was to examine electric energy consumption during sewage sludge treatment. The excess sewage sludge was aerobically stabilized and dewatered with a screw press. Organic matter varied from 48% to 56% in sludge after stabilization and dewatering. It proves that sludge was properly stabilized and it was possible to apply it as a fertilizer. Measurement factors for electric energy consumption for mechanically dewatered sewage sludge were determined, which ranged between 0.94 and 1.5 kWhm -3 with the average value at 1.17 kWhm -3 . The shares of devices used for sludge dewatering and aerobic stabilization in the total energy consumption of the plant were also established, which were 3% and 25% respectively. A model of energy consumption during sewage sludge treatment was estimated according to experimental data. Two models were applied: linear regression for dewatering process and segmented linear regression for aerobic stabilization. The segmented linear regression model was also applied to total energy consumption during sewage sludge treatment in the examined dairy WWTP. The research constitutes an introduction for further studies on defining a mathematical model used to optimize electric energy consumption by dairy WWTPs. Copyright © 2016 Elsevier Inc. All rights reserved.

Nitrogen removal characteristics analyzed with gas and microbial community in thermophilic aerobic digestion for piggery waste treatment.

PubMed

Lee, J W; Lee, H W; Kim, S W; Lee, S Y; Park, Y K; Han, J H; Choi, S I; Yi, Y S; Yun, Z

2004-01-01

In order to characterize the nitrogen conversion characteristics in a thermophilic aerobic digestion (TAD) system, a laboratory study has been conducted with the analysis of effluent gas and microbial community in the sludge samples. The lab TAD system was operated with HRT of 3 days and 60 degrees C. Based on the nitrogen mass balance, it has been found that about 2/3 of the daily load of nitrogen was converted to the gaseous form of nitrogen whereas cellular transformation and unmetabolized nitrogen accounted for about 1/3. Among the gaseous nitrogen transformation, significant amount of influent nitrogen had been converted to N2 gas (29% of influent N) and N2O (9% of influent N). Ammonia conversion was only 28% of influent N. The detection of N2O gas is a clear indication of the biological nitrogen reduction process in the thermophilic aerobic digester. No conclusive evidence for the existence of aerobic deammonification has been found. The microbial community analysis showed that thermophilic bacteria such as Bacillus thermocloacae, Bacillus sp. and Clostridial groups dominated in this TAD reactor. The diverse microbial community in TAD sludge may play an important role in removing both strong organics and nitrogen from piggery waste.

Kinetics and thermodynamics of biodegradation of hydrolyzed polyacrylamide under anaerobic and aerobic conditions.

PubMed

Zhao, Lanmei; Bao, Mutai; Yan, Miao; Lu, Jinren

2016-09-01

Kinetics and thermodynamics of hydrolyzed polyacrylamide (HPAM) biodegradation in anaerobic and aerobic activated sludge biochemical treatment systems were explored to determine the maximum rate and feasibility of HPAM biodegradation. The optimal nutrient proportions for HPAM biodegradation were determined to be 0.08g·L(-1) C6H12O6, 1.00g·L(-1) NH4Cl, 0.36g·L(-1) NaH2PO4 and 3.00g·L(-1) K2HPO4 using response surface methodology (RSM). Based on the kinetics, the maximum HPAM biodegradation rates were 16.43385mg·L(-1)·d(-1) and 2.463mg·L(-1)·d(-1) in aerobic and anaerobic conditions, respectively. The activation energy (Ea) of the aerobic biodegradation was 48.9897kJ·mol(-1). Entropy changes (ΔS) of biochemical treatment system decreased from 216.21J·K(-1) to 2.39J·K(-1). Thermodynamic windows of opportunity for HPAM biodegradation were drawn. And it demonstrated HPAM was biodegraded into acetic acid and CO2 under laboratory conditions. Growth-process equations for functional bacteria anaerobically grown on polyacrylic acid were constructed and it confirmed electron equivalence between substrate and product. Copyright © 2016 Elsevier Ltd. All rights reserved.

Recent advances on biosorption by aerobic granular sludge.

PubMed

Wang, Li; Liu, Xiang; Lee, Duu-Jong; Tay, Joo-Hwa; Zhang, Yi; Wan, Chun-Li; Chen, Xiao-Feng

2018-06-04

Aerobic granular sludge is a form of microbial auto-aggregation, and a promising biotechnology for wastewater treatment. This review aims at providing the first comprehensive, systematic, and in-depth overview on the application of aerobic granules as biosorbents. The target pollutants encompass heavy metals (both cationic and oxyanionic), nuclides, dyes, and inorganic non-metal substances. Different granule types are discussed, i.e. intact and fragmented, compact and fluffy, original and modified, and the effects of granule surface modification are introduced. A detailed comparison is conducted on the characteristics of granular biomass, the conditions of the adsorption tests, and the resultant performance towards various sorbates. Analytical and mathematical tools typically employed are presented, and possible interactions between the pollutants and granules are theorized, leading to an analysis on the mechanisms of the adsorption processes. Original granules appear highly effective towards cationic metals, while surface modification by organic and inorganic agents can expand their applicability to other pollutants. Combined with their advantages of high mechanical strength, density, and settling speed, aerobic granules possess exceptional potential in real wastewater treatment as biosorbents. Possible future research, both fundamental and practical, is suggested to gain more insights into the mechanism of their function, and to advance their industrial application. Copyright © 2018 Elsevier B.V. All rights reserved.

Methane oxidation in a crude oil contaminated aquifer: Delineation of aerobic reactions at the plume fringes

USGS Publications Warehouse

Amos, R.T.; Bekins, B.A.; Delin, G.N.; Cozzarelli, I.M.; Blowes, D.W.; Kirshtein, J.D.

2011-01-01

High resolution direct-push profiling over short vertical distances was used to investigate CH4 attenuation in a petroleum contaminated aquifer near Bemidji, Minnesota. The contaminant plume was delineated using dissolved gases, redox sensitive components, major ions, carbon isotope ratios in CH4 and CO2, and the presence of methanotrophic bacteria. Sharp redox gradients were observed near the water table. Shifts in ??13CCH4 from an average of - 57.6??? (?? 1.7???) in the methanogenic zone to - 39.6??? (?? 8.7???) at 105 m downgradient, strongly suggest CH4 attenuation through microbially mediated degradation. In the downgradient zone the aerobic/anaerobic transition is up to 0.5 m below the water table suggesting that transport of O2 across the water table is leading to aerobic degradation of CH4 at this interface. Dissolved N2 concentrations that exceeded those expected for water in equilibrium with the atmosphere indicated bubble entrapment followed by preferential stripping of O2 through aerobic degradation of CH4 or other hydrocarbons. Multivariate and cluster analysis were used to distinguish between areas of significant bubble entrapment and areas where other processes such as the infiltration of O 2 rich recharge water were important O2 transport mechanisms. ?? 2011 Elsevier B.V. All rights reserved.

Oxygen, the lead actor in the pathophysiologic drama: enactment of the trinity of normoxia, hypoxia, and hyperoxia in disease and therapy.

PubMed

Kulkarni, Aditi C; Kuppusamy, Periannan; Parinandi, Narasimham

2007-10-01

Aerobic life has evolved a dependence on molecular oxygen for its mere survival. Mitochondrial oxidative phosphorylation absolutely requires oxygen to generate the currency of energy in aerobes. The physiologic homeostasis of these organisms is strictly maintained by optimal cellular and tissue-oxygenation status through complex oxygen-sensing mechanisms, signaling cascades, and transport processes. In the event of fluctuating oxygen levels leading to either an increase (hyperoxia) or decrease (hypoxia) in cellular oxygen, the organism faces a crisis involving depletion of energy reserves, altered cell-signaling cascades, oxidative reactions/events, and cell death or tissue damage. Molecular oxygen is activated by both nonenzymatic and enzymatic mechanisms into highly reactive oxygen species (ROS). Aerobes have evolved effective antioxidant defenses to counteract the reactivity of ROS. Although the ROS are also required for many normal physiologic functions of the aerobes, overwhelming production of ROS coupled with their insufficient scavenging by endogenous antioxidants will lead to detrimental oxidative stress. Needless to say, molecular oxygen is at the center of oxygenation, oxidative phosphorylation, and oxidative stress. This review focuses on the biology and pathophysiology of oxygen, with an emphasis on transport, sensing, and activation of oxygen, oxidative phosphorylation, oxygenation, oxidative stress, and oxygen therapy.

CO2 – Intrinsic Product, Essential Substrate, and Regulatory Trigger of Microbial and Mammalian Production Processes

PubMed Central

Blombach, Bastian; Takors, Ralf

2015-01-01

Carbon dioxide formation mirrors the final carbon oxidation steps of aerobic metabolism in microbial and mammalian cells. As a consequence, CO2/HCO3− dissociation equilibria arise in fermenters by the growing culture. Anaplerotic reactions make use of the abundant CO2/HCO3− levels for refueling citric acid cycle demands and for enabling oxaloacetate-derived products. At the same time, CO2 is released manifold in metabolic reactions via decarboxylation activity. The levels of extracellular CO2/HCO3− depend on cellular activities and physical constraints such as hydrostatic pressures, aeration, and the efficiency of mixing in large-scale bioreactors. Besides, local CO2/HCO3− levels might also act as metabolic inhibitors or transcriptional effectors triggering regulatory events inside the cells. This review gives an overview about fundamental physicochemical properties of CO2/HCO3− in microbial and mammalian cultures effecting cellular physiology, production processes, metabolic activity, and transcriptional regulation. PMID:26284242

Aerobic Methane Oxidation in Alaskan Lakes Along a Latitudinal Transect

NASA Astrophysics Data System (ADS)

Martinez-Cruz, K. C.; Sepulveda-Jauregui, A.; Walter Anthony, K. M.; Anthony, P.; Thalasso, F.

2013-12-01

Karla Martinez-Cruz* **, Armando Sepulveda-Jauregui*, Katey M. Walter Anthony*, Peter Anthony*, and Frederic Thalasso**. * Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, Alaska. ** Biotechnology and Bioengineering Department, Cinvestav, Mexico city, D. F., Mexico. Methane (CH4) is the third most important greenhouse gas in the atmosphere, after carbon dioxide and water vapor. Boreal lakes play an important role in the current global warming by contributing as much as 6% of global atmospheric CH4 sources annually. On the other hand, aerobic methane oxidation (methanotrophy) in lake water is a fundamental process in global methane cycling that reduces the amount of CH4 emissions to the atmosphere. Several environmental factors affect aerobic methane oxidation in the water column both directly and indirectly, including concentration of CH4 and O2, temperature and carbon budgets of lakes. We analyzed the potential of aerobic methane oxidation (PMO) rates in incubations of water collected from 30 Alaskan lakes along a north-south transect during winter and summer 2011. Our findings showed an effect of CH4 and O2 concentrations, temperature and yedoma thawing permafrost on PMO activity in the lake water. The highest PMO rates were observed in summer by lakes situated on thawing yedoma permafrost, most of them located in the interior of Alaska. We also estimated that 60-80% of all CH4 produced in Alaskan lakes could be taken up by methanotrophs in the lake water column, showing the significant influence of aerobic methane oxidation of boreal lakes to the global CH4 budget.

Enteric bacteria in aerobically digested sludge.

PubMed Central

Farrah, S R; Bitton, G

1984-01-01

Indicator bacteria, Salmonella spp., and total aerobic bacteria were determined in samples of undigested sludge and sludge that had been treated by one or two stages of aerobic digestion. Aerobic sludge digestion reduced the level of indicator bacteria by 1 to 2 log10 per g. The level of Salmonella spp. was also reduced during aerobic treatment of sludge. In general, aerobic treatment of sludge reduced, but did not eliminate, indicator bacteria and Salmonella spp. PMID:6721492

Settling properties of aerobic granular sludge (AGS) and aerobic granular sludge molasses (AGSM)

NASA Astrophysics Data System (ADS)

Mat Saad, Azlina; Aini Dahalan, Farrah; Ibrahim, Naimah; Yasina Yusuf, Sara; Aqlima Ahmad, Siti; Khalil, Khalilah Abdul

2018-03-01

Aerobic granulation technology is applied to treat domestic and industrial wastewater. The Aerobic granular sludge (AGS) cultivated has strong properties that appears to be denser and compact in physiological structure compared to the conventional activated sludge. It offers rapid settling for solid:liquid separation in wastewater treatment. Aerobic granules were developed using sequencing batch reactor (SBR) with intermittent aerobic - anaerobic mode with 8 cycles in 24 hr. This study examined the settling velocity performance of cultivated aerobic granular sludge (AGS) and aerobic granular sludge molasses (AGSM). The elemental composition in both AGS and AGSM were determined using X-ray fluorescence (XRF). The results showed that AGSM has higher settling velocity 30.5 m/h compared to AGS.