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Sample records for active aerobic methanotrophs

  1. Identification of functionally active aerobic methanotrophs in sediments from an arctic lake using stable isotope probing

    USGS Publications Warehouse

    He, Ruo; Wooller, Matthew J.; Pohlman, John W.; Catranis, Catharine; Quensen, John; Tiedje, James M.; Leigh, Mary Beth

    2012-01-01

    Arctic lakes are a significant source of the greenhouse gas methane (CH4), but the role that methane oxidizing bacteria (methanotrophs) play in limiting the overall CH4 flux is poorly understood. Here, we used stable isotope probing (SIP) techniques to identify the metabolically active aerobic methanotrophs in upper sediments (0–1 cm) from an arctic lake in northern Alaska sampled during ice-free summer conditions. The highest CH4 oxidation potential was observed in the upper sediment (0–1 cm depth) with 1.59 μmol g wet weight-1 day-1 compared with the deeper sediment samples (1–3 cm, 3–5 cm and 5–10 cm), which exhibited CH4 oxidation potentials below 0.4 μmol g wet weight-1 day-1. Both type I and type II methanotrophs were directly detected in the upper sediment total communities using targeted primer sets based on 16S rRNA genes. Sequencing of 16S rRNA genes and functional genes (pmoA and mxaF) in the 13C-DNA from the upper sediment indicated that type I methanotrophs, mainly Methylobacter, Methylosoma, Methylomonas and Methylovulum miyakonense, dominated the assimilation of CH4. Methylotrophs, including the genera Methylophilus and/or Methylotenera, were also abundant in the 13CDNA. Our results show that a diverse microbial consortium acquired carbon from CH4 in the sediments of this arctic lake.

  2. Diversity of active aerobic methanotrophs along depth profiles of arctic and subarctic lake water column and sediments

    USGS Publications Warehouse

    He, Ruo; Wooller, Matthew J.; Pohlman, John W.; Quensen, John; Tiedje, James M.; Leigh, Mary Beth

    2012-01-01

    Methane (CH4) emitted from high-latitude lakes accounts for 2–6% of the global atmospheric CH4 budget. Methanotrophs in lake sediments and water columns mitigate the amount of CH4 that enters the atmosphere, yet their identity and activity in arctic and subarctic lakes are poorly understood. We used stable isotope probing (SIP), quantitative PCR (Q-PCR), pyrosequencing and enrichment cultures to determine the identity and diversity of active aerobic methanotrophs in the water columns and sediments (0–25 cm) from an arctic tundra lake (Lake Qalluuraq) on the north slope of Alaska and a subarctic taiga lake (Lake Killarney) in Alaska's interior. The water column CH4 oxidation potential for these shallow (~2m deep) lakes was greatest in hypoxic bottom water from the subarctic lake. The type II methanotroph, Methylocystis, was prevalent in enrichment cultures of planktonic methanotrophs from the water columns. In the sediments, type I methanotrophs (Methylobacter, Methylosoma and Methylomonas) at the sediment-water interface (0–1 cm) were most active in assimilating CH4, whereas the type I methanotroph Methylobacter and/or type II methanotroph Methylocystis contributed substantially to carbon acquisition in the deeper (15–20 cm) sediments. In addition to methanotrophs, an unexpectedly high abundance of methylotrophs also actively utilized CH4-derived carbon. This study provides new insight into the identity and activity of methanotrophs in the sediments and water from high-latitude lakes.

  3. Aerobic methane oxidation and methanotroph community composition during seasonal stratification in Mono Lake, California (USA).

    PubMed

    Carini, Stephen; Bano, Nasreen; LeCleir, Gary; Joye, Samantha B

    2005-08-01

    Patterns of aerobic methane (CH4) oxidation and associated methanotroph community composition were investigated during the development of seasonal stratification in Mono Lake, California (USA). CH4 oxidation rates were measured using a tritiated CH4 radiotracer technique. Fluorescence in situ hybridization (FISH), denaturing gradient gel electrophoresis (DGGE) and sequence analysis were used to characterize methanotroph community composition. A temporally shifting zone of elevated CH4 oxidation (59-123 nM day(-1)) was consistently associated with a suboxycline, microaerophilic zone that migrated upwards in the water column as stratification progressed. FISH analysis revealed stable numbers of type I (4.1-9.3 x 10(5) cells ml(-1)) and type II (1.4-3.4 x 10(5) cells ml(-1)) methanotrophs over depth and over time. Denaturing gradient gel electrophoresis and sequence analysis indicated slight shifts in methanotroph community composition despite stable absolute cell numbers. Variable CH4 oxidation rates in the presence of a relatively stable methanotroph population suggested that zones of high CH4 oxidation resulted from an increase in activity of a subset of the existing methanotroph population. These results challenge existing paradigms suggesting that zones of elevated CH4 oxidation activity result from the accumulation of methanotrophic biomass and illustrate that type II methanotrophs may be an important component of the methanotroph population in saline and/or alkaline pelagic environments.

  4. Characterization of methanotrophic bacterial populations in natural and agricultural aerobic soils of the European Russia

    NASA Astrophysics Data System (ADS)

    Kravchenko, Irina; Sukhacheva, Marina; Kizilova, Anna

    2014-05-01

    Atmospheric methane contributes to about 20% of the total radiative forcing by long-lived greenhouse gases, and microbial methane oxidation in upland soils is the only biological sink of methane. Microbial methane oxidation in aerated upland soils is estimated as 15 - 45 Tg yr-1 or 3-9% of the annual sink. Therefore there is need of extensive research to characterize methanotrophic activity in various ecosystems for possible application to reduce atmospheric methane fluxes and to minimize global climate change. The vast majority of known aerobic methanotrophs belongs to the Proteobacteria and placed in the families Methylococcaceae in the Gammaproteobacteria, and Methylocystaceae and Beijerinckiaceae in the Alphaproteobacteria. Known exceptions include the phylum Verrucomicrobia and uncultured methanotrophs such as Candidatus 'Methylomirabilis oxyfera' affiliated with the 'NC10' phylum. Plenty of studies of aerobic methane oxidation and key players of the process have been performed on various types of soils, and it was found that Methylocystis spp and uncultivated methanotrophs are abundant in upland soils. Two of the uncultured groups are upland soil cluster alphaproteobacteria (USCa) and gammaproteobacteria (USCg), as revealed by cultivation-independent surveys of pmoA diversity. Russia is extremely rich in soil types due to its vast territories, and most of these soils have never been investigated from the aspect of methanotrophy. This study addresses methane oxidation activity and diversity of aerobic methanotrophic bacteria in eight types of natural aerobic soils, four of which also had been under agricultural use. Methane fluxes have been measured by in situ static chamber method and methane oxidation rates in soil samples - by radioisotope tracer (14CH4) technique. Changes in methanotroph diversity and abundance were assessed by cloning and Sanger sequencing, and quantitative real-time PCR of pmoA genes. Methanotrophic population of unmanaged soils turned

  5. Monitoring Methanotrophic Bacteria in Hybrid Anaerobic-Aerobic Reactors with PCR and a Catabolic Gene Probe

    PubMed Central

    Miguez, Carlos B.; Shen, Chun F.; Bourque, Denis; Guiot, Serge R.; Groleau, Denis

    1999-01-01

    We attempted to mimic in small upflow anaerobic sludge bed (UASB) bioreactors the metabolic association found in nature between methanogens and methanotrophs. UASB bioreactors were inoculated with pure cultures of methanotrophs, and the bioreactors were operated by using continuous low-level oxygenation in order to favor growth and/or survival of methanotrophs. Unlike the reactors in other similar studies, the hybrid anaerobic-aerobic bioreactors which we used were operated synchronously, not sequentially. Here, emphasis was placed on monitoring various methanotrophic populations by using classical methods and also a PCR amplification assay based on the mmoX gene fragment of the soluble methane monooxygenase (sMMO). The following results were obtained: (i) under the conditions used, Methylosinus sporium appeared to survive better than Methylosinus trichosporium; (ii) the PCR method which we used could detect as few as about 2,000 sMMO gene-containing methanotrophs per g (wet weight) of granular sludge; (iii) inoculation of the bioreactors with pure cultures of methanotrophs contributed greatly to increases in the sMMO-containing population (although the sMMO-containing population decreased gradually with time, at the end of an experiment it was always at least 2 logs larger than the initial population before inoculation); (iv) in general, there was a good correlation between populations with the sMMO gene and populations that exhibited sMMO activity; and (v) inoculation with sMMO-positive cultures helped increase significantly the proportion of sMMO-positive methanotrophs in reactors, even after several weeks of operation under various regimes. At some point, anaerobic-aerobic bioreactors like those described here might be used for biodegradation of various chlorinated pollutants. PMID:9925557

  6. Assessing the Efficacy of the Aerobic Methanotrophic Biofilter in Methane Hydrate Environments

    SciTech Connect

    Valentine, David

    2012-09-30

    In October 2008 the University of California at Santa Barbara (UCSB) initiated investigations of water column methane oxidation in methane hydrate environments, through a project funded by the National Energy Technology Laboratory (NETL) entitled: assessing the efficacy of the aerobic methanotrophic biofilter in methane hydrate environments. This Final Report describes the scientific advances and discoveries made under this award as well as the importance of these discoveries in the broader context of the research area. Benthic microbial mats inhabit the sea floor in areas where reduced chemicals such as sulfide reach the more oxidizing water that overlies the sediment. We set out to investigate the role that methanotrophs play in such mats at locations where methane reaches the sea floor along with sulfide. Mats were sampled from several seep environments and multiple sets were grown in-situ at a hydrocarbon seep in the Santa Barbara Basin. Mats grown in-situ were returned to the laboratory and used to perform stable isotope probing experiments in which they were treated with 13C-enriched methane. The microbial community was analyzed, demonstrating that three or more microbial groups became enriched in methane?s carbon: methanotrophs that presumably utilize methane directly, methylotrophs that presumably consume methanol excreted by the methanotrophs, and sulfide oxidizers that presumably consume carbon dioxide released by the methanotrophs and methylotrophs. Methanotrophs reached high relative abundance in mats grown on methane, but other bacterial processes include sulfide oxidation appeared to dominate mats, indicating that methanotrophy is not a dominant process in sustaining these benthic mats, but rather a secondary function modulated by methane availability. Methane that escapes the sediment in the deep ocean typically dissolved into the overlying water where it is available to methanotrophic bacteria. We set out to better understand the efficacy of this

  7. Recurrence and Frequency of Disturbance have Cumulative Effect on Methanotrophic Activity, Abundance, and Community Structure

    PubMed Central

    Ho, Adrian; van den Brink, Erik; Reim, Andreas; Krause, Sascha M. B.; Bodelier, Paul L. E.

    2016-01-01

    Alternate prolonged drought and heavy rainfall is predicted to intensify with global warming. Desiccation-rewetting events alter the soil quality and nutrient concentrations which drive microbial-mediated processes, including methane oxidation, a key biogeochemical process catalyzed by methanotrophic bacteria. Although aerobic methanotrophs showed remarkable resilience to a suite of physical disturbances induced as a single event, their resilience to recurring disturbances is less known. Here, using a rice field soil in a microcosm study, we determined whether recurrence and frequency of desiccation-rewetting impose an accumulating effect on the methanotrophic activity. The response of key aerobic methanotroph subgroups (type Ia, Ib, and II) were monitored using qPCR assays, and was supported by a t-RFLP analysis. The methanotrophic activity was resilient to recurring desiccation-rewetting, but increasing the frequency of the disturbance by twofold significantly decreased methane uptake rate. Both the qPCR and t-RFLP analyses were congruent, showing the dominance of type Ia/Ib methanotrophs prior to disturbance, and after disturbance, the recovering community was predominantly comprised of type Ia (Methylobacter) methanotrophs. Both type Ib and type II (Methylosinus/Methylocystis) methanotrophs were adversely affected by the disturbance, but type II methanotrophs showed recovery over time, indicating relatively higher resilience to the disturbance. This revealed distinct, yet unrecognized traits among the methanotroph community members. Our results show that recurring desiccation-rewetting before a recovery in community abundance had an accumulated effect, compromising methanotrophic activity. While methanotrophs may recover well following sporadic disturbances, their resilience may reach a ‘tipping point’ where activity no longer recovered if disturbance persists and increase in frequency. PMID:26779148

  8. Diversity and Habitat Preferences of Cultivated and Uncultivated Aerobic Methanotrophic Bacteria Evaluated Based on pmoA as Molecular Marker

    PubMed Central

    Knief, Claudia

    2015-01-01

    Methane-oxidizing bacteria are characterized by their capability to grow on methane as sole source of carbon and energy. Cultivation-dependent and -independent methods have revealed that this functional guild of bacteria comprises a substantial diversity of organisms. In particular the use of cultivation-independent methods targeting a subunit of the particulate methane monooxygenase (pmoA) as functional marker for the detection of aerobic methanotrophs has resulted in thousands of sequences representing “unknown methanotrophic bacteria.” This limits data interpretation due to restricted information about these uncultured methanotrophs. A few groups of uncultivated methanotrophs are assumed to play important roles in methane oxidation in specific habitats, while the biology behind other sequence clusters remains still largely unknown. The discovery of evolutionary related monooxygenases in non-methanotrophic bacteria and of pmoA paralogs in methanotrophs requires that sequence clusters of uncultivated organisms have to be interpreted with care. This review article describes the present diversity of cultivated and uncultivated aerobic methanotrophic bacteria based on pmoA gene sequence diversity. It summarizes current knowledge about cultivated and major clusters of uncultivated methanotrophic bacteria and evaluates habitat specificity of these bacteria at different levels of taxonomic resolution. Habitat specificity exists for diverse lineages and at different taxonomic levels. Methanotrophic genera such as Methylocystis and Methylocaldum are identified as generalists, but they harbor habitat specific methanotrophs at species level. This finding implies that future studies should consider these diverging preferences at different taxonomic levels when analyzing methanotrophic communities. PMID:26696968

  9. Diversity and Habitat Preferences of Cultivated and Uncultivated Aerobic Methanotrophic Bacteria Evaluated Based on pmoA as Molecular Marker.

    PubMed

    Knief, Claudia

    2015-01-01

    Methane-oxidizing bacteria are characterized by their capability to grow on methane as sole source of carbon and energy. Cultivation-dependent and -independent methods have revealed that this functional guild of bacteria comprises a substantial diversity of organisms. In particular the use of cultivation-independent methods targeting a subunit of the particulate methane monooxygenase (pmoA) as functional marker for the detection of aerobic methanotrophs has resulted in thousands of sequences representing "unknown methanotrophic bacteria." This limits data interpretation due to restricted information about these uncultured methanotrophs. A few groups of uncultivated methanotrophs are assumed to play important roles in methane oxidation in specific habitats, while the biology behind other sequence clusters remains still largely unknown. The discovery of evolutionary related monooxygenases in non-methanotrophic bacteria and of pmoA paralogs in methanotrophs requires that sequence clusters of uncultivated organisms have to be interpreted with care. This review article describes the present diversity of cultivated and uncultivated aerobic methanotrophic bacteria based on pmoA gene sequence diversity. It summarizes current knowledge about cultivated and major clusters of uncultivated methanotrophic bacteria and evaluates habitat specificity of these bacteria at different levels of taxonomic resolution. Habitat specificity exists for diverse lineages and at different taxonomic levels. Methanotrophic genera such as Methylocystis and Methylocaldum are identified as generalists, but they harbor habitat specific methanotrophs at species level. This finding implies that future studies should consider these diverging preferences at different taxonomic levels when analyzing methanotrophic communities.

  10. Complete genome sequence of Methylocystis sp. strain SC2, an aerobic methanotroph with high-affinity methane oxidation potential.

    PubMed

    Dam, Bomba; Dam, Somasri; Kube, Michael; Reinhardt, Richard; Liesack, Werner

    2012-11-01

    Methylocystis sp. strain SC2 is an aerobic type II methanotroph isolated from a highly polluted aquifer in Germany. A specific trait of the SC2 strain is the expression of two isozymes of particulate methane monooxygenase with different methane oxidation kinetics. Here we report the complete genome sequence of this methanotroph that contains not only a circular chromosome but also two large plasmids.

  11. Planktonic and sediment-associated aerobic methanotrophs in two seep systems along the North American margin.

    PubMed

    Tavormina, Patricia L; Ussler, William; Orphan, Victoria J

    2008-07-01

    Methane vents are of significant geochemical and ecological importance. Notable progress has been made toward understanding anaerobic methane oxidation in marine sediments; however, the diversity and distribution of aerobic methanotrophs in the water column are poorly characterized. Both environments play an essential role in regulating methane release from the oceans to the atmosphere. In this study, the diversity of particulate methane monooxygenase (pmoA) and 16S rRNA genes from two methane vent environments along the California continental margin was characterized. The pmoA phylotypes recovered from methane-rich sediments and the overlying water column differed. Sediments harbored the greatest number of unique pmoA phylotypes broadly affiliated with the Methylococcaceae family, whereas planktonic pmoA phylotypes formed three clades that were distinct from the sediment-hosted methanotrophs and distantly related to established methanotrophic clades. Water column-associated phylotypes were highly similar between field sites, suggesting that planktonic methanotroph diversity is controlled primarily by environmental factors rather than geographical proximity. Analysis of 16S rRNA genes from methane-rich waters did not readily recover known methanotrophic lineages, with only a few phylotypes demonstrating distant relatedness to Methylococcus. The development of new pmo primers increased the recovery of monooxygenase genes from the water column and led to the discovery of a highly diverged monooxygenase sequence which is phylogenetically intermediate to Amo and pMMO. This sequence potentiates insight into the amo/pmo superfamily. Together, these findings lend perspective into the diversity and segregation of aerobic methanotrophs within different methane-rich habitats in the marine environment.

  12. Analysis of methane monooxygenase genes in mono lake suggests that increased methane oxidation activity may correlate with a change in methanotroph community structure.

    PubMed

    Lin, Ju-Ling; Joye, Samantha B; Scholten, Johannes C M; Schäfer, Hendrik; McDonald, Ian R; Murrell, J Colin

    2005-10-01

    Mono Lake is an alkaline hypersaline lake that supports high methane oxidation rates. Retrieved pmoA sequences showed a broad diversity of aerobic methane oxidizers including the type I methanotrophs Methylobacter (the dominant genus), Methylomicrobium, and Methylothermus, and the type II methanotroph Methylocystis. Stratification of Mono Lake resulted in variation of aerobic methane oxidation rates with depth. Methanotroph diversity as determined by analysis of pmoA using new denaturing gradient gel electrophoresis primers suggested that variations in methane oxidation activity may correlate with changes in methanotroph community composition.

  13. Methanotrophic activity and diversity of methanotrophs in volcanic geothermal soils at Pantelleria (Italy)

    NASA Astrophysics Data System (ADS)

    Gagliano, A. L.; D'Alessandro, W.; Tagliavia, M.; Parello, F.; Quatrini, P.

    2014-10-01

    Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic or geothermal soils are not only a source of methane, but are also sites of methanotrophic activity. Methanotrophs are able to consume 10-40 Tg of CH4 a-1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria (Italy), Favara Grande, whose total methane emission was previously estimated at about 2.5 Mg a-1 (t a-1). Laboratory incubation experiments with three top-soil samples from Favara Grande indicated methane consumption values of up to 59.2 nmol g-1 soil d.w. h-1. One of the three sites, FAV2, where the highest oxidation rate was detected, was further analysed on a vertical soil profile, the maximum methane consumption was measured in the top-soil layer, and values greater than 6.23 nmol g-1 h-1 were still detected up to a depth of 13 cm. The highest consumption rate was measured at 37 °C, but a still detectable consumption at 80 °C (> 1.25 nmol g-1 h-1) was recorded. The soil total DNA extracted from the three samples was probed by Polymerase Chain Reaction (PCR) using standard proteobacterial primers and newly designed verrucomicrobial primers, targeting the unique methane monooxygenase gene pmoA; the presence of methanotrophs was detected at sites FAV2 and FAV3, but not at FAV1, where harsher chemical-physical conditions and negligible methane oxidation were detected. The pmoA gene libraries from the most active site (FAV2) pointed to a high diversity of gammaproteobacterial methanotrophs, distantly related to Methylocaldum-Metylococcus genera, and the presence of the newly discovered acido-thermophilic Verrucomicrobia methanotrophs. Alphaproteobacteria of the genus Methylocystis were isolated from enrichment cultures under a methane

  14. Diversity and activity of methanotrophs in landfill cover soils with and without landfill gas recovery systems.

    PubMed

    Su, Yao; Zhang, Xuan; Xia, Fang-Fang; Zhang, Qi-Qi; Kong, Jiao-Yan; Wang, Jing; He, Ruo

    2014-05-01

    Aerobic CH4 oxidation plays an important role in mitigating CH4 release from landfills to the atmosphere. Therefore, in this study, oxidation activity and community of methanotrophs were investigated in a subtropical landfill. Among the three sites investigated, the highest CH4 concentration was detected in the landfill cover soil of the site (A) without a landfill gas (LFG) recovery system, although the refuse in the site had been deposited for a longer time (∼14-15 years) compared to the other two sites (∼6-11 years) where a LFG recovery system was applied. In April and September, the higher CH4 flux was detected in site A with 72.4 and 51.7gm(-2)d(-1), respectively, compared to the other sites. The abundance of methanotrophs assessed by quantification of pmoA varied with location and season. A linear relationship was observed between the abundance of methanotrophs and CH4 concentrations in the landfill cover soils (R=0.827, P<0.001). The key factors influencing the methanotrophic diversity in the landfill cover soils were pH, the water content and the CH4 concentration in the soil, of which pH was the most important factor. Type I methanotrophs, including Methylococcus, Methylosarcina, Methylomicrobium and Methylobacter, and type II methanotrophs (Methylocystis) were all detected in the landfill cover soils, with Methylocystis and Methylosarcina being the dominant genera. Methylocystis was abundant in the slightly acidic landfill cover soil, especially in September, and represented more than 89% of the total terminal-restriction fragment abundance. These findings indicated that the LFG recovery system, as well as physical and chemical parameters, affected the diversity and activity of methanotrophs in landfill cover soils.

  15. Alpha- and Gammaproteobacterial Methanotrophs Codominate the Active Methane-Oxidizing Communities in an Acidic Boreal Peat Bog

    PubMed Central

    Esson, Kaitlin C.; Lin, Xueju; Kumaresan, Deepak; Chanton, Jeffrey P.; Murrell, J. Colin

    2016-01-01

    The objective of this study was to characterize metabolically active, aerobic methanotrophs in an ombrotrophic peatland in the Marcell Experimental Forest, in Minnesota. Methanotrophs were investigated in the field and in laboratory incubations using DNA-stable isotope probing (SIP), expression studies on particulate methane monooxygenase (pmoA) genes, and amplicon sequencing of 16S rRNA genes. Potential rates of oxidation ranged from 14 to 17 μmol of CH4 g dry weight soil−1 day−1. Within DNA-SIP incubations, the relative abundance of methanotrophs increased from 4% in situ to 25 to 36% after 8 to 14 days. Phylogenetic analysis of the 13C-enriched DNA fractions revealed that the active methanotrophs were dominated by the genera Methylocystis (type II; Alphaproteobacteria), Methylomonas, and Methylovulum (both, type I; Gammaproteobacteria). In field samples, a transcript-to-gene ratio of 1 to 2 was observed for pmoA in surface peat layers, which attenuated rapidly with depth, indicating that the highest methane consumption was associated with a depth of 0 to 10 cm. Metagenomes and sequencing of cDNA pmoA amplicons from field samples confirmed that the dominant active methanotrophs were Methylocystis and Methylomonas. Although type II methanotrophs have long been shown to mediate methane consumption in peatlands, our results indicate that members of the genera Methylomonas and Methylovulum (type I) can significantly contribute to aerobic methane oxidation in these ecosystems. PMID:26873322

  16. Alpha- and Gammaproteobacterial Methanotrophs Codominate the Active Methane-Oxidizing Communities in an Acidic Boreal Peat Bog.

    PubMed

    Esson, Kaitlin C; Lin, Xueju; Kumaresan, Deepak; Chanton, Jeffrey P; Murrell, J Colin; Kostka, Joel E

    2016-04-01

    The objective of this study was to characterize metabolically active, aerobic methanotrophs in an ombrotrophic peatland in the Marcell Experimental Forest, in Minnesota. Methanotrophs were investigated in the field and in laboratory incubations using DNA-stable isotope probing (SIP), expression studies on particulate methane monooxygenase (pmoA) genes, and amplicon sequencing of 16S rRNA genes. Potential rates of oxidation ranged from 14 to 17 μmol of CH4g dry weight soil(-1)day(-1) Within DNA-SIP incubations, the relative abundance of methanotrophs increased from 4% in situ to 25 to 36% after 8 to 14 days. Phylogenetic analysis of the(13)C-enriched DNA fractions revealed that the active methanotrophs were dominated by the genera Methylocystis(type II;Alphaproteobacteria),Methylomonas, and Methylovulum(both, type I;Gammaproteobacteria). In field samples, a transcript-to-gene ratio of 1 to 2 was observed for pmoA in surface peat layers, which attenuated rapidly with depth, indicating that the highest methane consumption was associated with a depth of 0 to 10 cm. Metagenomes and sequencing of cDNA pmoA amplicons from field samples confirmed that the dominant active methanotrophs were Methylocystis and Methylomonas Although type II methanotrophs have long been shown to mediate methane consumption in peatlands, our results indicate that members of the genera Methylomonas and Methylovulum(type I) can significantly contribute to aerobic methane oxidation in these ecosystems.

  17. Aerobic methanotrophic communities at the Red Sea brine-seawater interface

    PubMed Central

    Abdallah, Rehab Z.; Adel, Mustafa; Ouf, Amged; Sayed, Ahmed; Ghazy, Mohamed A.; Alam, Intikhab; Essack, Magbubah; Lafi, Feras F.; Bajic, Vladimir B.; El-Dorry, Hamza; Siam, Rania

    2014-01-01

    The central rift of the Red Sea contains 25 brine pools with different physicochemical conditions, dictating the diversity and abundance of the microbial community. Three of these pools, the Atlantis II, Kebrit and Discovery Deeps, are uniquely characterized by a high concentration of hydrocarbons. The brine-seawater interface, described as an anoxic-oxic (brine-seawater) boundary, is characterized by a high methane concentration, thus favoring aerobic methane oxidation. The current study analyzed the aerobic free–living methane-oxidizing bacterial communities that potentially contribute to methane oxidation at the brine-seawater interfaces of the three aforementioned brine pools, using metagenomic pyrosequencing, 16S rRNA pyrotags and pmoA library constructs. The sequencing of 16S rRNA pyrotags revealed that these interfaces are characterized by high microbial community diversity. Signatures of aerobic methane-oxidizing bacteria were detected in the Atlantis II Interface (ATII-I) and the Kebrit Deep Upper (KB-U) and Lower (KB-L) brine-seawater interfaces. Through phylogenetic analysis of pmoA, we further demonstrated that the ATII-I aerobic methanotroph community is highly diverse. We propose four ATII-I pmoA clusters. Most importantly, cluster 2 groups with marine methane seep methanotrophs, and cluster 4 represent a unique lineage of an uncultured bacterium with divergent alkane monooxygenases. Moreover, non-metric multidimensional scaling (NMDS) based on the ordination of putative enzymes involved in methane metabolism showed that the Kebrit interface layers were distinct from the ATII-I and DD-I brine-seawater interfaces. PMID:25295031

  18. Rare bacteriohopanepolyols as markers for an autotrophic, intra-aerobic methanotroph

    NASA Astrophysics Data System (ADS)

    Kool, Dorien M.; Talbot, Helen M.; Rush, Darci; Ettwig, Katharina; Sinninghe Damsté, Jaap S.

    2014-07-01

    Bacteriohopanepolyols (BHPs) and their diagenetic products, hopanoids, are of great interest for their potential as biomarker lipids in both present day environments as well as in the geological record. Specific structural features such as methylation of the A-ring, and number and type of functional groups of C35 BHPs have been held characteristic for certain groups of organisms. Here we investigated the potential presence of BHPs in the unusual anaerobic methanotroph Methylomirabilis oxyfera and another Methylomirabilis sp. Although M. oxyfera thrives in anoxic settings, it uses internally produced molecular oxygen (from nitrite) for the oxidation of methane. We found that Methylomirabilis spp. synthesizes bacteriohopanehexol (BHP-hexol), -pentol, and -tetrol, and 3-methyl derivatives of each as major BHPs. None of the C-35 amino-BHPs that are more commonly observed in methanotrophs were detected. Our findings provide the first ever account of a 3-methyl-BHP-hexol, and only the second known source organism for BHP-hexol after Alicyclobacillus acidoterrestris. As the genes required for C3-methylation seem to be exclusively present in microorganisms with an aerobic metabolism, the abundant presence of 3-methyl-BHPs in Methylomirabilis spp. denotes for the first time the potential production of 3-methyl hopanoids in anoxic environments. Furthermore, with 13C-labeling experiments we show that M. oxyfera does not assimilate methane-carbon, but rather C from bicarbonate/CO2, into its BHPs. This implies that methanotroph-derived hopanoids do not necessarily exhibit a strongly depleted carbon isotopic signature, which is commonly anticipated with methanotrophy. This may have implications for the interpretation of the presence of hopanoids and their isotopic signature in the paleorecord.

  19. Autonomous application of quantitative PCR in the deep sea: in situ surveys of aerobic methanotrophs using the deep-sea environmental sample processor.

    PubMed

    Ussler, William; Preston, Christina; Tavormina, Patricia; Pargett, Doug; Jensen, Scott; Roman, Brent; Marin, Roman; Shah, Sunita R; Girguis, Peter R; Birch, James M; Orphan, Victoria; Scholin, Christopher

    2013-08-20

    Recent advances in ocean observing systems and genomic technologies have led to the development of the deep-sea environmental sample processor (D-ESP). The D-ESP filters particulates from seawater at depths up to 4000 m and applies a variety of molecular assays to the particulates, including quantitative PCR (qPCR), to identify particular organisms and genes in situ. Preserved samples enable laboratory-based validation of in situ results and expanded studies of genomic diversity and gene expression. Tests of the D-ESP at a methane-rich mound in the Santa Monica Basin centered on detection of 16S rRNA and particulate methane monooxygenase (pmoA) genes for two putative aerobic methanotrophs. Comparison of in situ qPCR results with laboratory-based assays of preserved samples demonstrates the D-ESP generated high-quality qPCR data while operating autonomously on the seafloor. Levels of 16S rRNA and pmoA cDNA detected in preserved samples are consistent with an active community of aerobic methanotrophs near the methane-rich mound. These findings are substantiated at low methane sites off Point Conception and in Monterey Bay where target genes are at or below detection limits. Successful deployment of the D-ESP is a major step toward developing autonomous systems to facilitate a wide range of marine microbiological investigations.

  20. Effect of afforestation and reforestation of pastures on the activity and population dynamics of methanotrophic bacteria.

    PubMed

    Singh, Brajesh K; Tate, Kevin R; Kolipaka, Gokul; Hedley, Carolyn B; Macdonald, Catriona A; Millard, Peter; Murrell, J Colin

    2007-08-01

    We investigated the effect of afforestation and reforestation of pastures on methane oxidation and the methanotrophic communities in soils from three different New Zealand sites. Methane oxidation was measured in soils from two pine (Pinus radiata) forests and one shrubland (mainly Kunzea ericoides var. ericoides) and three adjacent permanent pastures. The methane oxidation rate was consistently higher in the pine forest or shrubland soils than in the adjacent pasture soils. A combination of phospholipid fatty acid (PLFA) and stable isotope probing (SIP) analyses of these soils revealed that different methanotrophic communities were active in soils under the different vegetations. The C18 PLFAs (signature of type II methanotrophs) predominated under pine and shrublands, and C16 PLFAs (type I methanotrophs) predominated under pastures. Analysis of the methanotrophs by molecular methods revealed further differences in methanotrophic community structure under the different vegetation types. Cloning and sequencing and terminal-restriction fragment length polymorphism analysis of the particulate methane oxygenase gene (pmoA) from different samples confirmed the PLFA-SIP results that methanotrophic bacteria related to type II methanotrophs were dominant in pine forest and shrubland, and type I methanotrophs (related to Methylococcus capsulatus) were dominant in all pasture soils. We report that afforestation and reforestation of pastures caused changes in methane oxidation by altering the community structure of methanotrophic bacteria in these soils.

  1. Microbial diversity in sediments associated with a shallow methane seep in the tropical Timor Sea of Australia reveals a novel aerobic methanotroph diversity.

    PubMed

    Wasmund, Kenneth; Kurtböke, D Ipek; Burns, Kathryn A; Bourne, David G

    2009-05-01

    This study examined the diversity of Bacteria, Archaea and in particular aerobic methanotrophs associated with a shallow (84 m) methane seep in the tropical Timor Sea, Australia. Seepage of thermogenic methane was associated with a large carbonate hardground covered in coarse carbonate-rich sediments and various benthic organisms such as solitary corals. The diversity of Bacteria and Archaea was studied by analysis of cloned 16S rRNA genes, while aerobic methanotrophic bacteria were quantified using real-time PCR targeting the alpha-subunit of particulate methane monooxygenase (pmoA) genes and diversity was studied by analysis of cloned pmoA genes. Phylogenetic analysis of bacterial and archaeal 16S rRNA genes revealed diverse and mostly novel phylotypes related to sequences previously recovered from marine sediments. A small number of bacterial 16S rRNA gene sequences were related to aerobic methanotrophs distantly related to the genera Methylococcus and Methylocaldum. Real-time PCR targeting pmoA genes showed that the highest numbers of methanotrophs were present in surface sediments associated with the seep area. Phylogenetic analysis of pmoA sequences revealed that all phylotypes were novel and fell into two large clusters comprised of only marine sequences distantly related to the genera Methylococcus and Methylocaldum that were clearly divergent from terrestrial phylotypes. This study provides evidence for the existence of a novel microbial diversity and diverse aerobic methanotrophs that appear to constitute marine specialized lineages.

  2. Earthworm activity in a simulated landfill cover soil shifts the community composition of active methanotrophs.

    PubMed

    Kumaresan, Deepak; Héry, Marina; Bodrossy, Levente; Singer, Andrew C; Stralis-Pavese, Nancy; Thompson, Ian P; Murrell, J Colin

    2011-12-01

    Landfills represent a major source of methane in the atmosphere. In a previous study, we demonstrated that earthworm activity in landfill cover soil can increase soil methane oxidation capacity. In this study, a simulated landfill cover soil mesocosm (1 m × 0.15 m) was used to observe the influence of earthworms (Eisenia veneta) on the active methanotroph community composition, by analyzing the expression of the pmoA gene, which is responsible for methane oxidation. mRNA-based pmoA microarray analysis revealed that earthworm activity in landfill cover soil stimulated activity of type I methanotrophs (Methylobacter, Methylomonas, Methylosarcina spp.) compared to type II methanotrophs (particularly Methylocystis spp.). These results, along with previous studies of methanotrophs in landfill cover soil, can now be used to plan in situ field studies to integrate earthworm-induced methanotrophy with other landfill management practises in order to maximize soil methane oxidation and reduce methane emissions from landfills.

  3. Methanotrophic bacteria.

    PubMed Central

    Hanson, R S; Hanson, T E

    1996-01-01

    Methane-utilizing bacteria (methanotrophs) are a diverse group of gram-negative bacteria that are related to other members of the Proteobacteria. These bacteria are classified into three groups based on the pathways used for assimilation of formaldehyde, the major source of cell carbon, and other physiological and morphological features. The type I and type X methanotrophs are found within the gamma subdivision of the Proteobacteria and employ the ribulose monophosphate pathway for formaldehyde assimilation, whereas type II methanotrophs, which employ the serine pathway for formaldehyde assimilation, form a coherent cluster within the beta subdivision of the Proteobacteria. Methanotrophic bacteria are ubiquitous. The growth of type II bacteria appears to be favored in environments that contain relatively high levels of methane, low levels of dissolved oxygen, and limiting concentrations of combined nitrogen and/or copper. Type I methanotrophs appear to be dominant in environments in which methane is limiting and combined nitrogen and copper levels are relatively high. These bacteria serve as biofilters for the oxidation of methane produced in anaerobic environments, and when oxygen is present in soils, atmospheric methane is oxidized. Their activities in nature are greatly influenced by agricultural practices and other human activities. Recent evidence indicates that naturally occurring, uncultured methanotrophs represent new genera. Methanotrophs that are capable of oxidizing methane at atmospheric levels exhibit methane oxidation kinetics different from those of methanotrophs available in pure cultures. A limited number of methanotrophs have the genetic capacity to synthesize a soluble methane monooxygenase which catalyzes the rapid oxidation of environmental pollutants including trichloroethylene. PMID:8801441

  4. Dry/Wet Cycles Change the Activity and Population Dynamics of Methanotrophs in Rice Field Soil

    PubMed Central

    Ma, Ke; Conrad, Ralf

    2013-01-01

    The methanotrophs in rice field soil are crucial in regulating the emission of methane. Drainage substantially reduces methane emission from rice fields. However, it is poorly understood how drainage affects microbial methane oxidation. Therefore, we analyzed the dynamics of methane oxidation rates, composition (using terminal restriction fragment length polymorphism [T-RFLP]), and abundance (using quantitative PCR [qPCR]) of methanotroph pmoA genes (encoding a subunit of particulate methane monooxygenase) and their transcripts over the season and in response to alternate dry/wet cycles in planted paddy field microcosms. In situ methane oxidation accounted for less than 15% of total methane production but was enhanced by intermittent drainage. The dry/wet alternations resulted in distinct effects on the methanotrophic communities in different soil compartments (bulk soil, rhizosphere soil, surface soil). The methanotrophic communities of the different soil compartments also showed distinct seasonal dynamics. In bulk soil, potential methanotrophic activity and transcription of pmoA were relatively low but were significantly stimulated by drainage. In contrast, however, in the rhizosphere and surface soils, potential methanotrophic activity and pmoA transcription were relatively high but decreased after drainage events and resumed after reflooding. While type II methanotrophs dominated the communities in the bulk soil and rhizosphere soil compartments (and to a lesser extent also in the surface soil), it was the pmoA of type I methanotrophs that was mainly transcribed under flooded conditions. Drainage affected the composition of the methanotrophic community only minimally but strongly affected metabolically active methanotrophs. Our study revealed dramatic dynamics in the abundance, composition, and activity of the various type I and type II methanotrophs on both a seasonal and a spatial scale and showed strong effects of dry/wet alternation cycles, which enhanced

  5. Dry/Wet cycles change the activity and population dynamics of methanotrophs in rice field soil.

    PubMed

    Ma, Ke; Conrad, Ralf; Lu, Yahai

    2013-08-01

    The methanotrophs in rice field soil are crucial in regulating the emission of methane. Drainage substantially reduces methane emission from rice fields. However, it is poorly understood how drainage affects microbial methane oxidation. Therefore, we analyzed the dynamics of methane oxidation rates, composition (using terminal restriction fragment length polymorphism [T-RFLP]), and abundance (using quantitative PCR [qPCR]) of methanotroph pmoA genes (encoding a subunit of particulate methane monooxygenase) and their transcripts over the season and in response to alternate dry/wet cycles in planted paddy field microcosms. In situ methane oxidation accounted for less than 15% of total methane production but was enhanced by intermittent drainage. The dry/wet alternations resulted in distinct effects on the methanotrophic communities in different soil compartments (bulk soil, rhizosphere soil, surface soil). The methanotrophic communities of the different soil compartments also showed distinct seasonal dynamics. In bulk soil, potential methanotrophic activity and transcription of pmoA were relatively low but were significantly stimulated by drainage. In contrast, however, in the rhizosphere and surface soils, potential methanotrophic activity and pmoA transcription were relatively high but decreased after drainage events and resumed after reflooding. While type II methanotrophs dominated the communities in the bulk soil and rhizosphere soil compartments (and to a lesser extent also in the surface soil), it was the pmoA of type I methanotrophs that was mainly transcribed under flooded conditions. Drainage affected the composition of the methanotrophic community only minimally but strongly affected metabolically active methanotrophs. Our study revealed dramatic dynamics in the abundance, composition, and activity of the various type I and type II methanotrophs on both a seasonal and a spatial scale and showed strong effects of dry/wet alternation cycles, which enhanced

  6. Community structure, abundance, and activity of methanotrophs in the Zoige wetland of the Tibetan Plateau.

    PubMed

    Yun, Juanli; Zhuang, Guoqiang; Ma, Anzhou; Guo, Hongguang; Wang, Yanfen; Zhang, Hongxun

    2012-05-01

    The Zoige wetland of the Tibetan Plateau is a high-altitude tundra wetland and one of the biggest methane emission centers in China. In this study, methanotrophs with respect to community structure, abundance, and activity were investigated in peat soils collected in the vicinity of different marshland plants that dominate different regions of the wetland, including Polygonum amphibium, Carex muliensis, and Eleocharis valleculosa (EV). 16S rRNA gene and particulate methane monooxygenase gene (pmoA) clone library sequence data indicated the presence of methanotrophs with two genera, Methylobacter and Methylocystis. Methylococcus, like pmoA gene sequences, were also retrieved and showed low similarity to those from Methylococcus spp. and thus indicates the existence of novel methanotrophs in the Zoige wetland. Quantitative polymerase chain reaction (qPCR) assays were used to measure the abundance of methantrophs and detected 10(7) to 10(8) of total pmoA gene copies per gram dry weight of soil in the three marshes. Group-specific qPCR and reverse transcriptase qPCR results found that the Methylobacter genus dominates the wetland, and Methylocystis methanotrophs were less abundant, although this group of methanotrophs was estimated to be more active according to mRNA/DNA ratio. Furthermore, EV marsh demonstrated the highest methanotrophs abundance and activity among the three marshes investigated. Our study suggests that both type I and type II methanotrophs contribute to the methane oxidation in the Zoige wetland.

  7. The active methanotrophic community in a wetland from the High Arctic.

    PubMed

    Graef, Christiane; Hestnes, Anne Grethe; Svenning, Mette Marianne; Frenzel, Peter

    2011-08-01

    The dominant terminal process of carbon mineralization in most freshwater wetlands is methanogenesis. With methane being an important greenhouse gas, the predicted warming of the Arctic may provide a positive feedback. However, the amount of methane released to the atmosphere may be controlled by the activity of methane-oxidizing bacteria (methanotrophs) living in the oxic surface layer of wetlands. Previously, methanotrophs have been isolated and identified by genetic profiling in High Arctic wetlands showing the presence of only a few genotypes. Two isolates from Solvatnet (Ny-Ålesund, Spitsbergen; 79°N) are available: Methylobacter tundripaludum (type I) and Methylocystis rosea (type II), raising the question whether the low diversity is a cultivation effect. We have revisited Solvatnet applying stable isotope probing (SIP) with (13) C-labelled methane. 16S rRNA profiling revealed active type I methanotrophs including M. tundripaludum, while no active type II methanotrophs were identified. These results indicate that the extant M. tundripaludum is an active methane oxidizer at its locus typicus; furthermore, Methylobacter seems to be the dominant active genus. Diversity of methanotrophs was low as compared, e.g. to wetland rice fields in the Mediterranean. This low diversity suggests a high vulnerability of Arctic methanotroph communities, which deserves more attention.

  8. Single cell activity reveals direct electron transfer in methanotrophic consortia

    NASA Astrophysics Data System (ADS)

    McGlynn, Shawn E.; Chadwick, Grayson L.; Kempes, Christopher P.; Orphan, Victoria J.

    2015-10-01

    Multicellular assemblages of microorganisms are ubiquitous in nature, and the proximity afforded by aggregation is thought to permit intercellular metabolic coupling that can accommodate otherwise unfavourable reactions. Consortia of methane-oxidizing archaea and sulphate-reducing bacteria are a well-known environmental example of microbial co-aggregation; however, the coupling mechanisms between these paired organisms is not well understood, despite the attention given them because of the global significance of anaerobic methane oxidation. Here we examined the influence of interspecies spatial positioning as it relates to biosynthetic activity within structurally diverse uncultured methane-oxidizing consortia by measuring stable isotope incorporation for individual archaeal and bacterial cells to constrain their potential metabolic interactions. In contrast to conventional models of syntrophy based on the passage of molecular intermediates, cellular activities were found to be independent of both species intermixing and distance between syntrophic partners within consortia. A generalized model of electric conductivity between co-associated archaea and bacteria best fit the empirical data. Combined with the detection of large multi-haem cytochromes in the genomes of methanotrophic archaea and the demonstration of redox-dependent staining of the matrix between cells in consortia, these results provide evidence for syntrophic coupling through direct electron transfer.

  9. Shifts in Identity and Activity of Methanotrophs in Arctic Lake Sediments in Response to Temperature Changes

    PubMed Central

    He, Ruo; Wooller, Matthew J.; Pohlman, John W.; Quensen, John; Tiedje, James M.

    2012-01-01

    Methane (CH4) flux to the atmosphere is mitigated via microbial CH4 oxidation in sediments and water. As arctic temperatures increase, understanding the effects of temperature on the activity and identity of methanotrophs in arctic lake sediments is important to predicting future CH4 emissions. We used DNA-based stable-isotope probing (SIP), quantitative PCR (Q-PCR), and pyrosequencing analyses to identify and characterize methanotrophic communities active at a range of temperatures (4°C, 10°C, and 21°C) in sediments (to a depth of 25 cm) sampled from Lake Qalluuraq on the North Slope of Alaska. CH4 oxidation activity was measured in microcosm incubations containing sediments at all temperatures, with the highest CH4 oxidation potential of 37.5 μmol g−1 day−1 in the uppermost (depth, 0 to 1 cm) sediment at 21°C after 2 to 5 days of incubation. Q-PCR of pmoA and of the 16S rRNA genes of type I and type II methanotrophs, and pyrosequencing of 16S rRNA genes in 13C-labeled DNA obtained by SIP demonstrated that the type I methanotrophs Methylobacter, Methylomonas, and Methylosoma dominated carbon acquisition from CH4 in the sediments. The identity and relative abundance of active methanotrophs differed with the incubation temperature. Methylotrophs were also abundant in the microbial community that derived carbon from CH4, especially in the deeper sediments (depth, 15 to 20 cm) at low temperatures (4°C and 10°C), and showed a good linear relationship (R = 0.82) with the relative abundances of methanotrophs in pyrosequencing reads. This study describes for the first time how methanotrophic communities in arctic lake sediments respond to temperature variations. PMID:22522690

  10. Shifts in identity and activity of methanotrophs in arctic lake sediments in response to temperature changes.

    PubMed

    He, Ruo; Wooller, Matthew J; Pohlman, John W; Quensen, John; Tiedje, James M; Leigh, Mary Beth

    2012-07-01

    Methane (CH(4)) flux to the atmosphere is mitigated via microbial CH(4) oxidation in sediments and water. As arctic temperatures increase, understanding the effects of temperature on the activity and identity of methanotrophs in arctic lake sediments is important to predicting future CH(4) emissions. We used DNA-based stable-isotope probing (SIP), quantitative PCR (Q-PCR), and pyrosequencing analyses to identify and characterize methanotrophic communities active at a range of temperatures (4°C, 10°C, and 21°C) in sediments (to a depth of 25 cm) sampled from Lake Qalluuraq on the North Slope of Alaska. CH(4) oxidation activity was measured in microcosm incubations containing sediments at all temperatures, with the highest CH(4) oxidation potential of 37.5 μmol g(-1) day(-1) in the uppermost (depth, 0 to 1 cm) sediment at 21°C after 2 to 5 days of incubation. Q-PCR of pmoA and of the 16S rRNA genes of type I and type II methanotrophs, and pyrosequencing of 16S rRNA genes in (13)C-labeled DNA obtained by SIP demonstrated that the type I methanotrophs Methylobacter, Methylomonas, and Methylosoma dominated carbon acquisition from CH(4) in the sediments. The identity and relative abundance of active methanotrophs differed with the incubation temperature. Methylotrophs were also abundant in the microbial community that derived carbon from CH(4), especially in the deeper sediments (depth, 15 to 20 cm) at low temperatures (4°C and 10°C), and showed a good linear relationship (R = 0.82) with the relative abundances of methanotrophs in pyrosequencing reads. This study describes for the first time how methanotrophic communities in arctic lake sediments respond to temperature variations.

  11. Peatland succession induces a shift in the community composition of Sphagnum-associated active methanotrophs.

    PubMed

    Putkinen, Anuliina; Larmola, Tuula; Tuomivirta, Tero; Siljanen, Henri M P; Bodrossy, Levente; Tuittila, Eeva-Stiina; Fritze, Hannu

    2014-06-01

    Sphagnum-associated methanotrophs (SAM) are an important sink for the methane (CH4) formed in boreal peatlands. We aimed to reveal how peatland succession, which entails a directional change in several environmental variables, affects SAM and their activity. Based on the pmoA microarray results, SAM community structure changes when a peatland develops from a minerotrophic fen to an ombrotrophic bog. Methanotroph subtypes Ia, Ib, and II showed slightly contrasting patterns during succession, suggesting differences in their ecological niche adaptation. Although the direct DNA-based analysis revealed a high diversity of type Ib and II methanotrophs throughout the studied peatland chronosequence, stable isotope probing (SIP) of the pmoA gene indicated they were active mainly during the later stages of succession. In contrast, type Ia methanotrophs showed active CH4 consumption in all analyzed samples. SIP-derived (13)C-labeled 16S rRNA gene clone libraries revealed a high diversity of SAM in every succession stage including some putative Methylocella/Methyloferula methanotrophs that are not detectable with the pmoA-based approach. In addition, a high diversity of 16S rRNA gene sequences likely representing cross-labeled nonmethanotrophs was discovered, including a significant proportion of Verrucomicrobia-related sequences. These results help to predict the effects of changing environmental conditions on SAM communities and activity.

  12. Diversity and methane oxidation of active epibiotic methanotrophs on live Shinkaia crosnieri

    PubMed Central

    Watsuji, Tomo-o; Yamamoto, Asami; Takaki, Yoshihiro; Ueda, Kenji; Kawagucci, Shinsuke; Takai, Ken

    2014-01-01

    Shinkaia crosnieri is a galatheid crab that predominantly dwells in deep-sea hydrothermal systems in the Okinawa Trough, Japan. In this study, the phylogenetic diversity of active methanotrophs in the epibiotic microbial community on the setae of S. crosnieri was characterized by reverse transcription-polymerase chain reaction (RT-PCR) of a functional gene (pmoA) encoding a subunit of particulate methane monooxygenase. Phylogenetic analysis of pmoA transcript sequences revealed that the active epibiotic methanotrophs on S. crosnieri setae consisted of gammaproteobacterial type Ia and Ib methanotrophs. The effect of different RNA stabilization procedures on the abundance of pmoA and 16S rRNA transcripts in the epibiotic community was estimated by quantitative RT-PCR. Our novel RNA fixation method performed immediately after sampling effectively preserved cellular RNA assemblages, particularly labile mRNA populations, including pmoA mRNA. Methane consumption in live S. crosnieri was also estimated by continuous-flow incubation under atmospheric and in situ hydrostatic pressures, and provided a clear evidence of methane oxidation activity of the epibiotic microbial community, which was not significantly affected by hydrostatic pressure. Our study revealed the significant ecological function and nutritional contribution of epibiotic methanotrophs to the predominant S. crosnieri populations in the Okinawa Trough deep-sea hydrothermal systems. In conclusion, our study gave clear facts about diversity and methane oxidation of active methanotrophs in the epibiotic community associated with invertebrates. PMID:24401859

  13. Shifts in identity and activity of methanotrophs in arctic lake sediments in response to temperature changes

    USGS Publications Warehouse

    He, Ruo; Wooller, Matthew J.; Pohlman, John W.; Quensen, John; Tiedje, James M.; Leigh, Mary Beth

    2012-01-01

    Methane (CH4) flux to the atmosphere is mitigated via microbial CH4 oxidation in sediments and water. As arctic temperaturesincrease, understanding the effects of temperature on the activity and identity of methanotrophs in arctic lake sediments is importantto predicting future CH4 emissions. We used DNA-based stable-isotope probing (SIP), quantitative PCR (Q-PCR), andpyrosequencing analyses to identify and characterize methanotrophic communities active at a range of temperatures (4°C, 10°C,and 21°C) in sediments (to a depth of 25 cm) sampled from Lake Qalluuraq on the North Slope of Alaska. CH4 oxidation activitywas measured in microcosm incubations containing sediments at all temperatures, with the highest CH4 oxidation potential of37.5 mol g1 day1 in the uppermost (depth, 0 to 1 cm) sediment at 21°C after 2 to 5 days of incubation. Q-PCR of pmoA and ofthe 16S rRNA genes of type I and type II methanotrophs, and pyrosequencing of 16S rRNA genes in 13C-labeled DNA obtained bySIP demonstrated that the type I methanotrophs Methylobacter, Methylomonas, and Methylosoma dominated carbon acquisitionfrom CH4 in the sediments. The identity and relative abundance of active methanotrophs differed with the incubation temperature.Methylotrophs were also abundant in the microbial community that derived carbon from CH4, especially in the deeper sediments(depth, 15 to 20 cm) at low temperatures (4°C and 10°C), and showed a good linear relationship (R0.82) with the relativeabundances of methanotrophs in pyrosequencing reads. This study describes for the first time how methanotrophiccommunities in arctic lake sediments respond to temperature variations.

  14. Methanobactin: a copper binding compound having antibiotic and antioxidant activity isolated from methanotrophic bacteria

    DOEpatents

    DiSpirito, Alan A.; Zahn, James A.; Graham, David W.; Kim, Hyung J.; Alterman, Michail; Larive, Cynthia

    2007-04-03

    A means and method for treating bacterial infection, providing antioxidant activity, and chelating copper using a copper binding compound produced by methanotrophic bacteria is described. The compound, known as methanobactin, is the first of a new class of antibiotics having gram-positive activity. Methanobactin has been sequenced, and its structural formula determined.

  15. Methanotrophic activity and bacterial diversity in volcanic-geothermal soils at Pantelleria island (Italy)

    NASA Astrophysics Data System (ADS)

    Gagliano, A. L.; D'Alessandro, W.; Tagliavia, M.; Parello, F.; Quatrini, P.

    2014-04-01

    Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic/geothermal soils are source of methane, but also sites of methanotrophic activity. Methanotrophs are able to consume 10-40 Tg of CH4 a-1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria island (Italy), Favara Grande, whose total methane emission was previously estimated in about 2.5 t a-1. Laboratory incubation experiments with three top-soil samples from Favara Grande indicated methane consumption values up to 950 ng g-1 dry soil h-1. One of the three sites, FAV2, where the highest oxidation rate was detected, was further analysed on a vertical soil profile and the maximum methane consumption was measured in the top-soil layer but values > 100 ng g-1 h-1 were maintained up to a depth of 15 cm. The highest consumption rate was measured at 37 °C, but a still recognizable consumption at 80 °C (> 20 ng g-1 h-1) was recorded. In order to estimate the bacterial diversity, total soil DNA was extracted from Favara Grande and analysed using a Temporal Temperature Gradient gel Electrophoresis (TTGE) analysis of the amplified bacterial 16S rRNA gene. The three soil samples were probed by PCR using standard proteobacterial primers and newly designed verrucomicrobial primers targeting the unique methane monooxygenase gene pmoA; the presence of methanotrophs was detected in sites FAV2 and FAV3, but not in FAV1, where harsher chemical-physical conditions and negligible methane oxidation were detected. The pmoA gene libraries from the most active site FAV2 pointed out a high diversity of gammaproteobacterial methanotrophs distantly related to Methylococcus/Methylothermus genera and the presence of the newly discovered acido-thermophilic methanotrophs

  16. [Decline of Activity and Shifts in the Methanotrophic Community Structure of an Ombrotrophic Peat Bog after Wildfire].

    PubMed

    Danilova, O V; Belova, S E; Kulichevskaya, I S; Dedysh, S N

    2015-01-01

    This study examined potential disturbances of methanotrophic communities playing a key role in reducing methane emissions from the peat bog Tasin Borskoye, Vladimir oblast, Russia as a result of the 2007 wildfire. The potential activity of the methane-oxidizing filter in the burned peatland site and the abundance of indigenous methanotrophic bacteria were significantly reduced in comparison to the undisturbed site. Molecular analysis of methanotrophic community structure by means of PCR amplification and cloning of the pmoAgene encoding particulate methane monooxygenase revealed the replacement of typical peat-inhabiting, acidophilic type II methanotrophic bacteria with type I methanotrophs, which are less active in acidic environments. In summary, both the structure and the activity of the methane-oxidizing filter in burned peatland sites underwent significant changes, which were clearly pronounced even after 7 years of the natural ecosystem recovery. These results point to the long-term character of the disturbances caused by wildfire in peatlands.

  17. Cultivation and detection of endophytic aerobic methanotrophs isolated from Sphagnum species as a perspective for environmental biotechnology

    PubMed Central

    2014-01-01

    Enriched cultures of microorganisms are an essential step in the production of inoculum of these organisms for biotechnology and bioengineering. The potential application of methanotrophic microorganisms for removal of methane produced from landfills and coal mines as well as biodegradation of toxic compounds has been widely studied. Therefore, searching for new sources of methanotrophs can contribute to increasing the possibilities of biotechnology and bioengineering. Enrichment cultures of endophytic methanotrophs from Sphagnum sp. were initiated in NMS medium, a most widely used medium for cultivation of methanotrophic bacteria from various environments proposed in 1970 by Whittenbury. Incubation was carried out at 10, 20, 30, and 37°C with vigorous shaking on a shaker (180 rpm). The source of carbon and energy for endophytes were methane at the concentration range between 1-20%. It appeared that the consortium of endophytic bacteria grew only at the temperature of 20 and 30°C. During the culture of endophytes, the measurements of gas concentration showed a steady loss of methane and oxygen, as well as accumulation of carbon dioxide as a CH4 oxidation product. The use of FISH has made characterization of endophytic consortia possible. It turned out that the population of endophytes consists of type I and II methanotrophs as well as associated non-methanotrophic bacteria. Furthermore, we determined the potential of the examined bacteria for methane oxidation, which ranged up to 4,7 μMCH4 per ml of the population of endophytes per day. PMID:25401064

  18. Impact of freshwater diversion projects on diversity and activity of methanotrophic communities in freshwater wetlands

    NASA Astrophysics Data System (ADS)

    Isaac, J.; Schulz, C. J.; Childers, G. W.

    2009-12-01

    Methanotrophic bacteria are key players in the carbon cycle capable of using methane as a sole carbon and energy source. Methanotrophs are ubiquitous in soil environments and play a key role in decreasing methane flux from anaerobic environments to the atmosphere, reducing the concentration of this greenhouse gas. Wetlands are a particularly important source of methane to the atmosphere, even though methanotrophs can consume the majority of the methane produced. Decreases in methanotrophic activity in wetland environments due to disturbance can have negative impacts with regard to greenhouse gas emissions, especially if the impact is widespread. Currently, several freshwater diversion projects are active and/or scheduled to come online in south Louisiana, delivering freshwater, sediments, and nutrients to coastal wetlands en masse to help combat subsidence and coastal erosion. Along with freshwater, these diversions also deliver other components of the Mississippi River including substantial bicarbonate alkalinity, reactive nitrogen, and sulfate. Analogous to the large scale diversion projects are smaller restoration projects that deliver treated wastewater effluent to wetlands. In particular, the Joyce Wildlife Management Area (JWMA) in southeast Louisiana has been the recipient of ~5 million gallons of treated domestic effluent per day since 2006. Both the composition of the marsh receiving the effluent and the effluent itself have similarities to Mississippi River diversions. We collected pre and post JWMA sediment microbial community DNA and created cloned libraries of genes encoding particulate methane monooxygenase (pmoA) as a proxy for methanotrophic community composition. Water chemistry data was also collected. Shifts in methanotrophic community composition were apparent as well as shifts in water chemistry. The most notable shift in water chemistry was pH, which changed from mildly acidic to slightly alkaline conditions, due to the increased alkalinity of

  19. Stable Isotope Probing Analysis of the Diversity and Activity of Methanotrophic Bacteria in Soils from the Canadian High Arctic ▿

    PubMed Central

    Martineau, Christine; Whyte, Lyle G.; Greer, Charles W.

    2010-01-01

    The melting of permafrost and its potential impact on CH4 emissions are major concerns in the context of global warming. Methanotrophic bacteria have the capacity to mitigate CH4 emissions from melting permafrost. Here, we used quantitative PCR (qPCR), stable isotope probing (SIP) of DNA, denaturing gradient gel electrophoresis (DGGE) fingerprinting, and sequencing of the 16S rRNA and pmoA genes to study the activity and diversity of methanotrophic bacteria in active-layer soils from Ellesmere Island in the Canadian high Arctic. Results showed that most of the soils had the capacity to oxidize CH4 at 4°C and at room temperature (RT), but the oxidation rates were greater at RT than at 4°C and were significantly enhanced by nutrient amendment. The DGGE banding patterns associated with active methanotrophic bacterial populations were also different depending on the temperature of incubation and the addition of nutrients. Sequencing of the 16S rRNA and pmoA genes indicated a low diversity of the active methanotrophic bacteria, with all methanotroph 16S rRNA and pmoA gene sequences being related to type I methanotrophs from Methylobacter and Methylosarcina. The dominance of type I methanotrophs over type II methanotrophs in the native soil samples was confirmed by qPCR of the 16S rRNA gene with primers specific for these two groups of bacteria. The 16S rRNA and pmoA gene sequences related to those of Methylobacter tundripaludum were found in all soils, regardless of the incubation conditions, and they might therefore play a role in CH4 degradation in situ. This work is providing new information supporting the potential importance of Methylobacter spp. in Arctic soils found in previous studies and contributes to the limited body of knowledge on methanotrophic activity and diversity in this extreme environment. PMID:20622133

  20. Metagenomic identification of active methanogens and methanotrophs in serpentinite springs of the Voltri Massif, Italy

    PubMed Central

    Thornton, Christopher N.; Hyer, Alex; Twing, Katrina I.; Longino, August A.; Lang, Susan Q.; Lilley, Marvin D.; Früh-Green, Gretchen L.; Schrenk, Matthew O.

    2017-01-01

    The production of hydrogen and methane by geochemical reactions associated with the serpentinization of ultramafic rocks can potentially support subsurface microbial ecosystems independent of the photosynthetic biosphere. Methanogenic and methanotrophic microorganisms are abundant in marine hydrothermal systems heavily influenced by serpentinization, but evidence for methane-cycling archaea and bacteria in continental serpentinite springs has been limited. This report provides metagenomic and experimental evidence for active methanogenesis and methanotrophy by microbial communities in serpentinite springs of the Voltri Massif, Italy. Methanogens belonging to family Methanobacteriaceae and methanotrophic bacteria belonging to family Methylococcaceae were heavily enriched in three ultrabasic springs (pH 12). Metagenomic data also suggest the potential for hydrogen oxidation, hydrogen production, carbon fixation, fermentation, and organic acid metabolism in the ultrabasic springs. The predicted metabolic capabilities are consistent with an active subsurface ecosystem supported by energy and carbon liberated by geochemical reactions within the serpentinite rocks of the Voltri Massif. PMID:28149702

  1. Effect of temperature on denitrifying methanotrophic activity of 'Candidatus Methylomirabilis oxyfera'.

    PubMed

    Kampman, Christel; Piai, Laura; Hendrickx, Tim L G; Temmink, Hardy; Zeeman, Grietje; Buisman, Cees J N

    2014-01-01

    The activity of denitrifying methanotrophic bacteria at 11-30 °C was assessed in short-term experiments. The aim was to determine the feasibility of applying denitrifying methanotrophic bacteria in low-temperature anaerobic wastewater treatment. This study showed that biomass enriched at 21 °C had an optimum temperature of 20-25 °C and that activity dropped as temperature was increased to 30 °C. Biomass enriched at 30 °C had an optimum temperature of 25-30 °C. These results indicated that biomass from low-temperature inocula adjusted to the enrichment temperature and that low-temperature enrichment is suitable for applications in low-temperature wastewater treatment. Biomass growth at ≤20 °C still needs to be studied.

  2. Long-term effects of mineral versus organic fertilizers on activity and structure of the methanotrophic community in agricultural soils.

    PubMed

    Seghers, Dave; Top, Eva M; Reheul, Dirk; Bulcke, Robert; Boeckx, Pascal; Verstraete, Willy; Siciliano, Steven D

    2003-10-01

    Agricultural practices, such as mineral nitrogen fertilization, have an impact on the soil's ability to oxidize methane, but little is known about the shifts in the methanotrophic community composition associated with these practices. Therefore, the long-term effect of both mineral (NH4NO3) and organic (manure and GFT-compost) fertilizer applications on the soil methanotrophic community activity and structure were investigated. Both high and low affinity methane oxidation rates were lower in the soil treated with mineral fertilizer compared to the other soils. An enhanced nitrate concentration was observed in the mineral fertilized soil but nitrate did not show a direct affect on the high affinity methane oxidation. In contrast, the low affinity methane oxidation was slowed down by increased nitrate concentrations, which suggests a direct effect of nitrate on low affinity methane oxidation. Denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA gene fragments specific for methanotrophs revealed a distinct community between the mineral and organic fertilized soils as extra Type I methanotrophic bands (phylotypes) became visible in the organic fertilized soils. These phylotypes were not visible in the patterns of the added organic fertilizers suggesting an indirect effect of the organic fertilizers on the methanotrophic community. Additionally, a molecular analysis was performed after the low affinity methane oxidation test. The enhanced methane concentrations used in the test enriched certain low affinity methanotrophs in the organic fertilized soils but not in the mineral fertilized soil. Supporting the molecular and functional observations, fatty acids characteristic for methanotrophs were less abundant in the soil treated with mineral fertilizer compared to the soil treated with compost. In conclusion, the function and molecular and chemical composition of the methanotrophic community are all altered in soil fertilized with mineral fertilizer.

  3. Diversity of the active methanotrophic community in acidic peatlands as assessed by mRNA and SIP-PLFA analyses.

    PubMed

    Chen, Yin; Dumont, Marc G; McNamara, Niall P; Chamberlain, Paul M; Bodrossy, Levente; Stralis-Pavese, Nancy; Murrell, J Colin

    2008-02-01

    The active methanotroph community was investigated for the first time in heather (Calluna)-covered moorlands and Sphagnum/Eriophorum-covered UK peatlands. Direct extraction of mRNA from these soils facilitated detection of expression of methane monooxygenase genes, which revealed that particulate methane monooxygenase and not soluble methane monooxygenase was probably responsible for CH(4) oxidation in situ, because only pmoA transcripts (encoding a subunit of particulate methane monooxygenase) were readily detectable. Differences in methanotroph community structures were observed between the Calluna-covered moorland and Sphagnum/Eriophorum-covered gully habitats. As with many other Sphagnum-covered peatlands, the Sphagnum/Eriophorum-covered gullies were dominated by Methylocystis. Methylocella and Methylocapsa-related species were also present. Methylobacter-related species were found as demonstrated by the use of a pmoA-based diagnostic microarray. In Calluna-covered moorlands, in addition to Methylocella and Methylocystis, a unique group of peat-associated type I methanotrophs (Gammaproteobacteria) and a group of uncultivated type II methanotrophs (Alphaproteobacteria) were also found. The pmoA sequences of the latter were only distantly related to Methylocapsa and also to the RA-14 group of methanotrophs, which are believed to be involved in oxidation of atmospheric concentrations of CH(4). Soil samples were also labelled with (13)CH(4), and subsequent analysis of the (13)C-labelled phospholipid fatty acids (PLFAs) showed that 16:1 omega 7, 18:1 omega 7 and 18:1 omega 9 were the major labelled PLFAs. The presence of (13)C-labelled 18:1 omega 9, which was not a major PLFA of any extant methanotrophs, indicated the presence of novel methanotrophs in this peatland.

  4. Revisiting methanotrophic communities in sewage treatment plants.

    PubMed

    Ho, Adrian; Vlaeminck, Siegfried E; Ettwig, Katharina F; Schneider, Bellinda; Frenzel, Peter; Boon, Nico

    2013-04-01

    The methanotrophic potential in sewage treatment sludge was investigated. We detected a diverse aerobic methanotrophic community that potentially plays a significant role in mitigating methane emission in this environment. The results suggest that community structure was determined by conditions specific to the processes in a sewage treatment plant.

  5. The importance of methanotrophic activity in geothermal soils of Pantelleria island (Italy)

    NASA Astrophysics Data System (ADS)

    D'Alessandro, Walter; Gagliano, Antonina Lisa; Quatrini, Paola; Parello, Francesco

    2013-04-01

    Methane is a major contributor to the greenhouse effect, its atmospheric concentration being more than doubled since the XIX century. Every year 22 Tg of methane are released to the atmosphere from several natural and anthropogenic sources. Natural sources include geothermal/volcanic areas but the estimation of the total methane emission from these areas is currently not well defined since the balance between emission through degassing and microbial oxidation within the soils is not well known. Microbial oxidation in soils contributes globally for about 3-9% to the removal of methane from the atmosphere and recent studies evidenced methanotrophic activity also in soils of volcanic/geothermal areas despite their harsh environmental conditions (high temperatures, low pH and high concentrations of H2S and NH3). Methanotrophs are a diverse group of bacteria that are able to metabolize methane as their only source of carbon and energy and are found within the Alpha and Gamma classes of Proteobacteria and within the phylum Verrucomicrobia. Our purpose was to study the interaction between methanotrophic communities and the methane emitted from the geothermally most active site of Pantelleria island (Italy), Favara Grande, whose total methane emission has been previously estimated in about 2.5 t/a. Laboratory incubation experiments with soil samples from Favara Grande showed methane consumption values of up to 9500 ng g-1 dry soil per hour while soils collected outside the geothermal area consume less than 6 ng g-1 h-1. The maximum consumption was measured in the shallowest part of the soil profile (1-3 cm) and high values (>100 ng g-1 h-1) were maintained up to a depht of 15 cm. Furthermore, the highest consumption was measured at 37°C, and a still recognizable consumption (>20 ng g-1 h-1) at 80°C, with positive correlation with the methane concentration in the incubation atmosphere. These results can be considered a clear evidence of the presence of methanotrophs that

  6. Effects of granular activated carbon on methane removal performance and methanotrophic community of a lab-scale bioreactor.

    PubMed

    Lee, Eun-Hee; Choi, Sun-Ah; Yi, Taewoo; Kim, Tae Gwan; Lee, Sang-Don; Cho, Kyung-Suk

    2015-01-01

    Two identical lab-scale bioreactor systems were operated to examine the effects of granular activated carbon (GAC) on methane removal performance and methanotrophic community. Both bioreactor systems removed methane completely at a CH4 loading rate of 71.2 g-CH4·d(-1) for 17 days. However, the methane removal efficiency declined to 88% in the bioreactor without GAC, while the bioreactor amended with GAC showed greater methane removal efficiency of 97% at a CH4 loading rate of 107.5 g-CH4·d(-1). Although quantitative real-time PCR showed that methanotrophic populations were similar levels of 5-10 × 10(8) pmoA gene copy number·VSS(-1) in both systems, GAC addition changed the methanotrophic community composition of the bioreactor systems. Microarray assay revealed that GAC enhanced the type I methanotrophic genera including Methylobacter, Methylomicrobium, and Methylomonas of the system, which suggests that GAC probably provided a favorable environment for type I methanotrophs. These results indicated that GAC is a promising support material in bioreactor systems for CH4 mitigation.

  7. Diverse electron sources support denitrification under hypoxia in the obligate methanotroph Methylomicrobium album strain BG8

    PubMed Central

    Kits, K. Dimitri; Campbell, Dustin J.; Rosana, Albert R.; Stein, Lisa Y.

    2015-01-01

    Aerobic methane-oxidizing bacteria (MOB) are a diverse group of microorganisms that are ubiquitous in natural environments. Along with anaerobic MOB and archaea, aerobic methanotrophs are critical for attenuating emission of methane to the atmosphere. Clearly, nitrogen availability in the form of ammonium and nitrite have strong effects on methanotrophic activity and their natural community structures. Previous findings show that nitrite amendment inhibits the activity of some cultivated methanotrophs; however, the physiological pathways that allow some strains to transform nitrite, expression of gene inventories, as well as the electron sources that support this activity remain largely uncharacterized. Here we show that Methylomicrobium album strain BG8 utilizes methane, methanol, formaldehyde, formate, ethane, ethanol, and ammonia to support denitrification activity under hypoxia only in the presence of nitrite. We also demonstrate that transcript abundance of putative denitrification genes, nirS and one of two norB genes, increased in response to nitrite. Furthermore, we found that transcript abundance of pxmA, encoding the alpha subunit of a putative copper-containing monooxygenase, increased in response to both nitrite and hypoxia. Our results suggest that expression of denitrification genes, found widely within genomes of aerobic methanotrophs, allow the coupling of substrate oxidation to the reduction of nitrogen oxide terminal electron acceptors under oxygen limitation. The present study expands current knowledge of the metabolic flexibility of methanotrophs by revealing that a diverse array of electron donors support nitrite reduction to nitrous oxide under hypoxia. PMID:26500622

  8. Short-term variations of methane concentrations and methanotrophic activity in a coastal inlet (Eckernförde Bay, Germany)

    NASA Astrophysics Data System (ADS)

    Richner, Dominik; Niemann, Helge; Steinle, Lea; Schneider von Deimling, Jens; Urban, Peter; Hoffmann, Jasper; Schmidt, Mark; Treude, Tina; Lehmann, Moritz

    2016-04-01

    Large quantities of methane are produced in anoxic sediments of continental margins and may be liberated into the overlying water column and, potentially, into the atmosphere. However, a sequence of microbially mediated methane oxidation pathways in sediments and the water column mitigate the contribution of oceans to the atmospheric methane budget. Of particular importance are methanotrophic bacteria in the water column that mediate the aerobic oxidation of methane (MOx), and represent the final sink for methane before its release to the atmosphere where it acts as a potent greenhouse gas. However methane cycling in (aerobic) marine waters is not well constrained. Particularly little is known about spatiotemporal aspects of MOx activity and the underlying key physical, chemical and biological factors. Here we show results from our investigations on methane dynamics on very short time scales of hours to days in the Eckernförde Bay (E-Bay), a costal inlet of the Baltic Sea in northern Germany featuring seasonal bottom water hypoxia/anoxia. In autumn 2014, we observed highly spatiotemporal variations in water column methane contents and MOx activity: Anoxic bottom waters in a trough in the northern part of the bay contained extremely high methane concentrations of up to 800 nM, which sharply declined at the midwater redox interface (methane remained supersaturated with respect to the atmospheric equilibrium throughout the water column at all times). The methane decrease at the redox interface was related to highly active MOx communities consuming methane under microoxic conditions at rates of up 40 nM/d. About 12 hours later, the methane content and the extend of bottom water anoxia was much lower and MOx activity was highly reduced in the northern part but strongly elevated in the southern part of the bay. A few days later, bottom water anoxia, methane loading and MOx activity was partially re-established. In this contribution, we will discuss potential forcing

  9. [Methanotrophic bacteria of acid sphagnum bogs].

    PubMed

    Dedysh, S N

    2002-01-01

    Acid sphagnum bogs cover a considerable part of the territory of Russia and are an important natural source of biogenic methane, which is formed in their anaerobic layers. A considerable portion of this methane is consumed in the aerobic part of the bog profile by acidophilic methanotrophic bacteria, which comprise the methane filter of sphagnum bogs and decrease CH4 emission to the atmosphere. For a long time, these bacteria escaped isolation, which became possible only after the elucidation of the optimal conditions of their functioning in situ: pH 4.5 to 5.5; temperature, from 15 to 20 degrees C; and low salt concentration in the solution. Reproduction of these conditions and rejection of earlier used media with a high content of biogenic elements allowed methanotrophic bacteria of two new genera and species--Methylocella palustris and Methylocapsa acidophila--to be isolated from the peat of sphagnum bogs of the northern part of European Russia and West Siberia. These bacteria are well adapted to the conditions in cold, acid, oligotrophic sphagnum bogs. They grow in a pH range of 4.2-7.5 with an optimum at 5.0-5.5, prefer moderate temperatures (15-25 degrees C) and media with a low content of mineral salts (200-500 mg/l), and are capable of active nitrogen fixation. Design of fluorescently labeled 16S rRNA-targeted oligonucleotide probes for the detection of Methylocella palustris and Methylocapsa acidophila and their application to the analysis of sphagnum peat samples showed that these bacteria represent dominant populations of methanotrophs with a density of 10(5)-10(6) cells/g peat. In addition to Methylocella and Methylocapsa populations, one more abundant population of methanotrophs was revealed (10(6) cells/g peat), which were phylogenetically close to the genus Methylocystis.

  10. WWOX loss activates aerobic glycolysis.

    PubMed

    Abu-Remaileh, Muhannad; Seewaldt, Victoria L; Aqeilan, Rami I

    2015-01-01

    Cancer cells undergo reprogramming of glucose metabolism to limit energy production to glycolysis-a state known as "aerobic glycolysis." Hypoxia-inducible factor 1 (HIF1α) is a transcription factor that regulates many genes responsible for this switch. As discussed here, new data suggest that the tumor suppressor WW domain-containing oxidoreductase (WWOX) modulates HIF1α, thereby regulating this metabolic state.

  11. WWOX loss activates aerobic glycolysis

    PubMed Central

    Abu-Remaileh, Muhannad; Seewaldt, Victoria L; Aqeilan, Rami I

    2015-01-01

    Cancer cells undergo reprogramming of glucose metabolism to limit energy production to glycolysis—a state known as “aerobic glycolysis.” Hypoxia-inducible factor 1 (HIF1α) is a transcription factor that regulates many genes responsible for this switch. As discussed here, new data suggest that the tumor suppressor WW domain-containing oxidoreductase (WWOX) modulates HIF1α, thereby regulating this metabolic state. PMID:27308416

  12. Transcriptional activities of methanogens and methanotrophs vary with methane emission flux in rice soils under chronic nutrient constraints of phosphorus and potassium

    NASA Astrophysics Data System (ADS)

    Sheng, Rong; Chen, Anlei; Zhang, Miaomiao; Whiteley, Andrew S.; Kumaresan, Deepak; Wei, Wenxue

    2016-12-01

    Nutrient status in soil is crucial for the growth and development of plants which indirectly or directly affect the ecophysiological functions of resident soil microorganisms. Soil methanogens and methanotrophs can be affected by soil nutrient availabilities and plant growth, which in turn modulate methane (CH4) emissions. Here, we assessed whether deficits in soil-available phosphorus (P) and potassium (K) modulated the activities of methanogens and methanotrophs in a long-term (20 year) experimental system involving limitation in either one or both nutrients. Results showed that a large amount of CH4 was emitted from paddy soil at rice tillering stage (flooding) while CH4 flux was minimum at ripening stage (drying). Compared to soils amended with NPK fertiliser treatment, the soils without P input significantly reduced methane flux rates, whereas those without K input did not. Under P limitation, methanotroph transcript copy number significantly increased in tandem with a decrease in methanogen transcript abundance, suggesting that P-deficiency-induced changes in soil physio-chemical properties, in tandem with rice plant growth, might constrain the activity of methanogens, whereas the methanotrophs might be adaptive to this soil environment. In contrast, lower transcript abundance of both methanogen and methanotrophs were observed in K-deficient soils. Assessments of community structures based upon transcripts indicated that soils deficient in P induced greater shifts in the active methanotrophic community than K-deficient soils, while similar community structures of active methanogens were observed in both treatments. These results suggested that the population dynamics of methanogens and methanotrophs could vary along with the changes in plant growth states and soil properties induced by nutrient deficiency.

  13. Draft Genome Sequences of Gammaproteobacterial Methanotrophs Isolated from Marine Ecosystems

    PubMed Central

    Flynn, James D.; Hirayama, Hisako; Sakai, Yasuyoshi; Dunfield, Peter F.; Knief, Claudia; Op den Camp, Huub J. M.; Jetten, Mike S. M.; Khmelenina, Valentina N.; Trotsenko, Yuri A.; Murrell, J. Colin; Semrau, Jeremy D.; Svenning, Mette M.; Stein, Lisa Y.; Kyrpides, Nikos; Shapiro, Nicole; Woyke, Tanja; Bringel, Françoise; Vuilleumier, Stéphane; DiSpirito, Alan A.

    2016-01-01

    The genome sequences of Methylobacter marinus A45, Methylobacter sp. strain BBA5.1, and Methylomarinum vadi IT-4 were obtained. These aerobic methanotrophs are typical members of coastal and hydrothermal vent marine ecosystems. PMID:26798114

  14. Methanotrophic bacteria in oilsands tailings ponds of northern Alberta

    PubMed Central

    Saidi-Mehrabad, Alireza; He, Zhiguo; Tamas, Ivica; Sharp, Christine E; Brady, Allyson L; Rochman, Fauziah F; Bodrossy, Levente; Abell, Guy CJ; Penner, Tara; Dong, Xiaoli; Sensen, Christoph W; Dunfield, Peter F

    2013-01-01

    We investigated methanotrophic bacteria in slightly alkaline surface water (pH 7.4–8.7) of oilsands tailings ponds in Fort McMurray, Canada. These large lakes (up to 10 km2) contain water, silt, clay and residual hydrocarbons that are not recovered in oilsands mining. They are primarily anoxic and produce methane but have an aerobic surface layer. Aerobic methane oxidation was measured in the surface water at rates up to 152 nmol CH4 ml−1 water d−1. Microbial diversity was investigated via pyrotag sequencing of amplified 16S rRNA genes, as well as by analysis of methanotroph-specific pmoA genes using both pyrosequencing and microarray analysis. The predominantly detected methanotroph in surface waters at all sampling times was an uncultured species related to the gammaproteobacterial genus Methylocaldum, although a few other methanotrophs were also detected, including Methylomonas spp. Active species were identified via 13CH4 stable isotope probing (SIP) of DNA, combined with pyrotag sequencing and shotgun metagenomic sequencing of heavy 13C-DNA. The SIP-PCR results demonstrated that the Methylocaldum and Methylomonas spp. actively consumed methane in fresh tailings pond water. Metagenomic analysis of DNA from the heavy SIP fraction verified the PCR-based results and identified additional pmoA genes not detected via PCR. The metagenome indicated that the overall methylotrophic community possessed known pathways for formaldehyde oxidation, carbon fixation and detoxification of nitrogenous compounds but appeared to possess only particulate methane monooxygenase not soluble methane monooxygenase. PMID:23254511

  15. Evidence of intense archaeal and bacterial methanotrophic activity in the Black Sea water column.

    PubMed

    Durisch-Kaiser, Edith; Klauser, Lucia; Wehrli, Bernhard; Schubert, Carsten

    2005-12-01

    In the northwestern Black Sea, methane oxidation rates reveal that above shallow and deep gas seeps methane is removed from the water column as efficiently as it is at sites located off seeps. Hence, seeps should not have a significant impact on the estimated annual flux of approximately 4.1 x 10(9) mol methane to the atmosphere [W. S. Reeburgh, B. B. Ward, S. C. Wahlen, K. A. Sandbeck, K. A. Kilatrick, and L. J. Kerkhof, Deep-Sea Res. 38(Suppl. 2):S1189-S1210, 1991]. Both the stable carbon isotopic composition of dissolved methane and the microbial community structure analyzed by fluorescent in situ hybridization provide strong evidence that microbially mediated methane oxidation occurs. At the shelf, strong isotope fractionation was observed above high-intensity seeps. This effect was attributed to bacterial type I and II methanotrophs, which on average accounted for 2.5% of the DAPI (4',6'-diamidino-2-phenylindole)-stained cells in the whole oxic water column. At deep sites, in the oxic-anoxic transition zone, strong isotopic fractionation of methane overlapped with an increased abundance of Archaea and Bacteria, indicating that these organisms are involved in the oxidation of methane. In underlying anoxic water, we successfully identified the archaeal methanotrophs ANME-1 and ANME-2, eachof which accounted for 3 to 4% of the total cell counts. ANME-1 and ANME-2 appear as single cells in anoxicwater, compared to the sediment, where they may form cell aggregates with sulfate-reducing bacteria (A. Boetius, K. Ravenschlag, C. J. Schubert, D. Rickert, F. Widdel, A. Giesecke, R. Amann, B. B. Jørgensen, U. Witte, and O. Pfannkuche, Nature 407:623-626, 2000; V. J. Orphan, C. H. House, K.-U. Hinrichs, K. D. McKeegan, and E. F. DeLong, Proc. Natl. Acad. Sci. USA 99:7663-7668, 2002).

  16. Genetic Tools for the Industrially Promising Methanotroph Methylomicrobium buryatense

    SciTech Connect

    Puri, AW; Owen, S; Chu, F; Chavkin, T; Beck, DAC; Kalyuzhnaya, MG; Lidstrom, ME

    2015-02-10

    Aerobic methanotrophs oxidize methane at ambient temperatures and pressures and are therefore attractive systems for methane-based bioconversions. In this work, we developed and validated genetic tools for Methylomicrobium buryatense, a haloalkaliphilic gammaproteobacterial (type I) methanotroph. M. buryatense was isolated directly on natural gas and grows robustly in pure culture with a 3-h doubling time, enabling rapid genetic manipulation compared to many other methanotrophic species. As a proof of concept, we used a sucrose counterselection system to eliminate glycogen production in M. buryatense by constructing unmarked deletions in two redundant glycogen synthase genes. We also selected for a more genetically tractable variant strain that can be conjugated with small incompatibility group P (IncP)-based broad-host-range vectors and determined that this capability is due to loss of the native plasmid. These tools make M. buryatense a promising model system for studying aerobic methanotroph physiology and enable metabolic engineering in this bacterium for industrial biocatalysis of methane.

  17. Field-Scale Stable-Isotope Probing of Active Methanotrophs in a Landfill-Cover Soil

    NASA Astrophysics Data System (ADS)

    Schroth, M. H.; Henneberger, R.; Chiri, E.

    2012-12-01

    The greenhouse gas methane (CH4) is an important contributor to global climate change. While its atmospheric concentration is increasing, a large portion of produced CH4 never reaches the atmosphere, but is consumed by aerobic methane-oxidizing bacteria (MOB). The latter are ubiquitous in soils and utilize CH4 as sole source of energy and carbon. Among other methods, MOB may be differentiated based on characteristic phospholipid fatty acids (PLFA). Stable-isotope probing (SIP) on PLFA has been widely applied to identify active members of MOB communities in laboratory incubation studies, but results are often difficult to extrapolate to the field. Thus, novel field-scale approaches are needed to link activity and identity of MOB in their natural environment. We present results of field experiments in which we combined PLFA-SIP with gas push-pull tests (GPPTs) to label active MOB at the field-scale while simultaneously quantifying CH4 oxidation activity. During a SIP-GPPT, a mixture of reactive (here 13CH4, O2) and non-reactive tracer gases (e.g., Ar, Ne, He) is injected into the soil at a location of interest. Thereafter, gas flow is reversed and the gas mixture diluted with soil air is extracted from the same location and sampled periodically. Rate constants for CH4 oxidation can be calculated by analyzing breakthrough curves of 13CH4 and a suitable non-reactive tracer gas. SIP-GPPTs were performed in a landfill-cover soil, and feasibility of this novel approach was tested at several locations along a gradient of MOB activity and soil temperature. Soil samples were collected before and after SIP-GPPTs, total PLFA were extracted, and incorporation of 13C in the polar lipid fraction was analyzed. Potential CH4 oxidation rates derived from SIP-GPPTs were similar to those derived from regular GPPTs (using unlabeled CH4) performed at the same locations prior to SIP-GPPTs, indicating that application of 13CH4 did not adversely affect bacterial CH4 oxidation rates. Rates

  18. Methane Oxidation and Molecular Characterization of Methanotrophs from a Former Mercury Mine Impoundment.

    PubMed

    Baesman, Shaun M; Miller, Laurence G; Wei, Jeremy H; Cho, Yirang; Matys, Emily D; Summons, Roger E; Welander, Paula V; Oremland, Ronald S

    2015-06-23

    The Herman Pit, once a mercury mine, is an impoundment located in an active geothermal area. Its acidic waters are permeated by hundreds of gas seeps. One seep was sampled and found to be composed of mostly CO₂ with some CH₄ present. The δ(13)CH₄ value suggested a complex origin for the methane: i.e., a thermogenic component plus a biological methanogenic portion. The relatively (12)C-enriched CO₂ suggested a reworking of the ebullitive methane by methanotrophic bacteria. Therefore, we tested bottom sediments for their ability to consume methane by conducting aerobic incubations of slurried materials. Methane was removed from the headspace of live slurries, and subsequent additions of methane resulted in faster removal rates. This activity could be transferred to an artificial, acidic medium, indicating the presence of acidophilic or acid-tolerant methanotrophs, the latter reinforced by the observation of maximum activity at pH = 4.5 with incubated slurries. A successful extraction of sterol and hopanoid lipids characteristic of methanotrophs was achieved, and their abundances greatly increased with increased sediment methane consumption. DNA extracted from methane-oxidizing enrichment cultures was amplified and sequenced for pmoA genes that aligned with methanotrophic members of the Gammaproteobacteria. An enrichment culture was established that grew in an acidic (pH 4.5) medium via methane oxidation.

  19. Methane Oxidation and Molecular Characterization of Methanotrophs from a Former Mercury Mine Impoundment

    PubMed Central

    Baesman, Shaun M.; Miller, Laurence G.; Wei, Jeremy H.; Cho, Yirang; Matys, Emily D.; Summons, Roger E.; Welander, Paula V.; Oremland, Ronald S.

    2015-01-01

    The Herman Pit, once a mercury mine, is an impoundment located in an active geothermal area. Its acidic waters are permeated by hundreds of gas seeps. One seep was sampled and found to be composed of mostly CO2 with some CH4 present. The δ13CH4 value suggested a complex origin for the methane: i.e., a thermogenic component plus a biological methanogenic portion. The relatively 12C-enriched CO2 suggested a reworking of the ebullitive methane by methanotrophic bacteria. Therefore, we tested bottom sediments for their ability to consume methane by conducting aerobic incubations of slurried materials. Methane was removed from the headspace of live slurries, and subsequent additions of methane resulted in faster removal rates. This activity could be transferred to an artificial, acidic medium, indicating the presence of acidophilic or acid-tolerant methanotrophs, the latter reinforced by the observation of maximum activity at pH = 4.5 with incubated slurries. A successful extraction of sterol and hopanoid lipids characteristic of methanotrophs was achieved, and their abundances greatly increased with increased sediment methane consumption. DNA extracted from methane-oxidizing enrichment cultures was amplified and sequenced for pmoA genes that aligned with methanotrophic members of the Gammaproteobacteria. An enrichment culture was established that grew in an acidic (pH 4.5) medium via methane oxidation. PMID:27682090

  20. Methane oxidation and molecular characterization of methanotrophs from a former mercury mine impoundment

    USGS Publications Warehouse

    Baesman, Shaun; Miller, Laurence G.; Wei, Jeremy H.; Cho, Yirang; Matys, Emily D.; Summons, Roger E.; Welander, Paula V.; Oremland, Ronald S.

    2015-01-01

    The Herman Pit, once a mercury mine, is an impoundment located in an active geothermal area. Its acidic waters are permeated by hundreds of gas seeps. One seep was sampled and found to be composed of mostly CO2 with some CH4 present. The δ13CH4 value suggested a complex origin for the methane: i.e., a thermogenic component plus a biological methanogenic portion. The relatively 12C-enriched CO2 suggested a reworking of the ebullitive methane by methanotrophic bacteria. Therefore, we tested bottom sediments for their ability to consume methane by conducting aerobic incubations of slurried materials. Methane was removed from the headspace of live slurries, and subsequent additions of methane resulted in faster removal rates. This activity could be transferred to an artificial, acidic medium, indicating the presence of acidophilic or acid-tolerant methanotrophs, the latter reinforced by the observation of maximum activity at pH = 4.5 with incubated slurries. A successful extraction of sterol and hopanoid lipids characteristic of methanotrophs was achieved, and their abundances greatly increased with increased sediment methane consumption. DNA extracted from methane-oxidizing enrichment cultures was amplified and sequenced for pmoA genes that aligned with methanotrophic members of the Gammaproteobacteria. An enrichment culture was established that grew in an acidic (pH 4.5) medium via methane oxidation.

  1. Survival and Recovery of Methanotrophic Bacteria Starved Under Oxic and Anoxic Conditions

    NASA Technical Reports Server (NTRS)

    Roslev, Peter; King, Gary M.

    1994-01-01

    The effects of carbon deprivation on survival of methanotrophic bacteria were compared in cultures incubated in the presence and absence of oxygen in the starvation medium. Survival and recovery of the examined methanotrophs were generally highest for cultures starved under anoxic conditions as indicated by poststarvation measurements of methane oxidation, tetrazolium salt reduction, plate counts, and protein synthesis. Methylosinus trichosporium OB3b survived up to 6 weeks of carbon deprivation under anoxic conditions while maintaining a physiological state that allowed relatively rapid (hours) methane oxidation after substrate addition. A small fraction of cells starved under oxic and anoxic conditions (4 and 10%, respectively) survived more than 10 weeks but required several days for recovery on plates and in liquid medium. A non-spore-forming methanotroph, strain WP 12, displayed 36 to 118% of its initial methane oxidation capacity after 5 days of carbon deprivation. Oxidation rates varied with growth history prior to the experiments as well as with starvation conditions. Strain WP 12 starved under anoxic conditions showed up to 90% higher methane oxidation activity and 46% higher protein production after starvation than did cultures starved under oxic conditions. Only minor changes in biomass and niorpholow were seen for methanotrophic bacteria starved tinder anoxic conditions. In contrast, starvation under oxic conditions resulted in morphology changes and an initial 28 to 35% loss of cell protein. These data suggest that methanotrophic bacteria can survin,e carbon deprivation under anoxic conditions by using maintenance energy derived Solelyr from an anaerobic endogenous metabolism. This capability could partly explain a significant potential for methane oxidation in environments not continuously, supporting aerobic methanotrophic growth.

  2. Survival and Recovery of Methanotrophic Bacteria Starved under Oxic and Anoxic Conditions †

    PubMed Central

    Roslev, Peter; King, Gary M.

    1994-01-01

    The effects of carbon deprivation on survival of methanotrophic bacteria were compared in cultures incubated in the presence and absence of oxygen in the starvation medium. Survival and recovery of the examined methanotrophs were generally highest for cultures starved under anoxic conditions as indicated by poststarvation measurements of methane oxidation, tetrazolium salt reduction, plate counts, and protein synthesis. Methylosinus trichosporium OB3b survived up to 6 weeks of carbon deprivation under anoxic conditions while maintaining a physiological state that allowed relatively rapid (hours) methane oxidation after substrate addition. A small fraction of cells starved under oxic and anoxic conditions (4 and 10%, respectively) survived more than 10 weeks but required several days for recovery on plates and in liquid medium. A non-spore-forming methanotroph, strain WP 12, displayed 36 to 118% of its initial methane oxidation capacity after 5 days of carbon deprivation. Oxidation rates varied with growth history prior to the experiments as well as with starvation conditions. Strain WP 12 starved under anoxic conditions showed up to 90% higher methane oxidation activity and 46% higher protein production after starvation than did cultures starved under oxic conditions. Only minor changes in biomass and morphology were seen for methanotrophic bacteria starved under anoxic conditions. In contrast, starvation under oxic conditions resulted in morphology changes and an initial 28 to 35% loss of cell protein. These data suggest that methanotrophic bacteria can survive carbon deprivation under anoxic conditions by using maintenance energy derived solely from an anaerobic endogenous metabolism. This capability could partly explain a significant potential for methane oxidation in environments not continuously supporting aerobic methanotrophic growth. PMID:16349336

  3. Aerobic Physical Activity and the Leadership of Principals

    ERIC Educational Resources Information Center

    Kiser, Kari

    2016-01-01

    The purpose of this study was to explore if there was a connection between regular aerobic physical activity and the stress and energy levels of principals as they reported it. To begin the research, the current aerobic physical activity level of principals was discovered. Additionally, the energy and stress levels of the principals who do engage…

  4. Changes in methane oxidation activity and methanotrophic community composition in saline alkaline soils.

    PubMed

    Serrano-Silva, Nancy; Valenzuela-Encinas, César; Marsch, Rodolfo; Dendooven, Luc; Alcántara-Hernández, Rocio J

    2014-05-01

    The soil of the former Lake Texcoco is a saline alkaline environment where anthropogenic drainage in some areas has reduced salt content and pH. Potential methane (CH4) consumption rates were measured in three soils of the former Lake Texcoco with different electrolytic conductivity (EC) and pH, i.e. Tex-S1 a >18 years drained soil (EC 0.7 dS m(-1), pH 8.5), Tex-S2 drained for ~10 years (EC 9.0 dS m(-1), pH 10.3) and the undrained Tex-S3 (EC 84.8 dS m(-1), pH 10.3). An arable soil from Alcholoya (EC 0.7 dS m(-1), pH 6.7), located nearby Lake Texcoco was used as control. Methane oxidation in the soil Tex-S1 (lowest EC and pH) was similar to that in the arable soil from Alcholoya (32.5 and 34.7 mg CH4 kg(-1) dry soil day(-1), respectively). Meanwhile, in soils Tex-S2 and Tex-S3, the potential CH4 oxidation rates were only 15.0 and 12.8 mg CH4 kg(-1) dry soil day(-1), respectively. Differences in CH4 oxidation were also related to changes in the methane-oxidizing communities in these soils. Sequence analysis of pmoA gene showed that soils differed in the identity and number of methanotrophic phylotypes. The Alcholoya soil and Tex-S1 contained phylotypes grouped within the upland soil cluster gamma and the Jasper Ridge, California JR-2 clade. In soil Tex-S3, a phylotype related to Methylomicrobium alcaliphilum was detected.

  5. Aerobic Activity--Do Physical Education Programs Provide Enough?

    ERIC Educational Resources Information Center

    McGing, Eileen

    1989-01-01

    High school physical education curricula should concentrate less on sport skill development and competition, and more on health-related fitness and aerobic activity. Results are reported from a study of the type and amount of aerobic exercise provided in 29 high school physical education programs in a large metropolitan area. (IAH)

  6. Draft Genome Sequence of the Moderately Halophilic Methanotroph Methylohalobius crimeensis Strain 10Ki

    PubMed Central

    Sharp, Christine E.; Smirnova, Angela V.; Kalyuzhnaya, Marina G.; Bringel, Françoise; Hirayama, Hisako; Jetten, Mike S. M.; Khmelenina, Valentina N.; Klotz, Martin G.; Knief, Claudia; Kyrpides, Nikos; Op den Camp, Huub J. M.; Reshetnikov, Alexander S.; Sakai, Yasuyoshi; Shapiro, Nicole; Trotsenko, Yuri A.; Vuilleumier, Stéphane; Woyke, Tanja

    2015-01-01

    Methylohalobius crimeensis strain 10Ki is a moderately halophilic aerobic methanotroph isolated from a hypersaline lake in the Crimean Peninsula, Ukraine. This organism has the highest salt tolerance of any cultured methanotroph. Here, we present a draft genome sequence of this bacterium. PMID:26067976

  7. Autotrophic carbon dioxide fixation via the Calvin-Benson-Bassham cycle by the denitrifying methanotroph "Candidatus Methylomirabilis oxyfera".

    PubMed

    Rasigraf, Olivia; Kool, Dorien M; Jetten, Mike S M; Sinninghe Damsté, Jaap S; Ettwig, Katharina F

    2014-04-01

    Methane is an important greenhouse gas and the most abundant hydrocarbon in the Earth's atmosphere. Methanotrophic microorganisms can use methane as their sole energy source and play a crucial role in the mitigation of methane emissions in the environment. "Candidatus Methylomirabilis oxyfera" is a recently described intra-aerobic methanotroph that is assumed to use nitric oxide to generate internal oxygen to oxidize methane via the conventional aerobic pathway, including the monooxygenase reaction. Previous genome analysis has suggested that, like the verrucomicrobial methanotrophs, "Ca. Methylomirabilis oxyfera" encodes and transcribes genes for the Calvin-Benson-Bassham (CBB) cycle for carbon assimilation. Here we provide multiple independent lines of evidence for autotrophic carbon dioxide fixation by "Ca. Methylomirabilis oxyfera" via the CBB cycle. The activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO), a key enzyme of the CBB cycle, in cell extracts from an "Ca. Methylomirabilis oxyfera" enrichment culture was shown to account for up to 10% of the total methane oxidation activity. Labeling studies with whole cells in batch incubations supplied with either (13)CH4 or [(13)C]bicarbonate revealed that "Ca. Methylomirabilis oxyfera" biomass and lipids became significantly more enriched in (13)C after incubation with (13)C-labeled bicarbonate (and unlabeled methane) than after incubation with (13)C-labeled methane (and unlabeled bicarbonate), providing evidence for autotrophic carbon dioxide fixation. Besides this experimental approach, detailed genomic and transcriptomic analysis demonstrated an operational CBB cycle in "Ca. Methylomirabilis oxyfera." Altogether, these results show that the CBB cycle is active and plays a major role in carbon assimilation by "Ca. Methylomirabilis oxyfera" bacteria. Our results suggest that autotrophy might be more widespread among methanotrophs than was previously assumed and implies that a methanotrophic

  8. Diversity of methanotroph communities in a basalt aquifer.

    PubMed

    Newby, D T; Reed, D W; Petzke, L M; Igoe, A L; Delwiche, M E; Roberto, F F; McKinley, J P; Whiticar, M J; Colwell, F S

    2004-06-01

    Methanotrophic bacteria play an important role in global cycling of carbon and co-metabolism of contaminants. Methanotrophs from pristine regions of the Snake River Plain Aquifer (SRPA; Idaho, USA) were studied in order to gain insight into the native groundwater communities' genetic potential to carry out TCE co-metabolism. Wells were selected that were proximal to a TCE plume believed to be undergoing natural attenuation. Methane concentrations ranged from 1 to >1000 nM. Carbon isotope ratios and diversity data together suggest that the SRPA contains active communities of methanotrophs that oxidize microbially produced methane. Microorganisms removed from groundwater by filtration were used as inocula for enrichments or frozen immediately and DNA was subsequently extracted for molecular characterization. Primers that specifically target methanotroph 16S rRNA genes or genes that code for subunits of soluble or particulate methane monooxygenase, mmoX and pmoA, respectively, were used to characterize the indigenous methanotrophs via PCR, cloning, RFLP analysis, and sequencing. Type I methanotroph clones aligned with Methylomonas, Methylocaldum, and Methylobacter sequences and a distinct 16S rRNA phylogenetic lineage grouped near Methylobacter. The majority of clone sequences in type II methanotroph 16S rRNA, pmoA, and mmoX gene libraries grouped closely with sequences in the Methylocystis genus. A subset of the type II methanotroph clones from the aquifer had sequences that aligned most closely to Methylosinus trichosporium OB3b and Methylocystis spp., known TCE-co-metabolizing methanotrophs.

  9. High resolution depth distribution of Bacteria, Archaea, methanotrophs, and methanogens in the bulk and rhizosphere soils of a flooded rice paddy

    PubMed Central

    Lee, Hyo Jung; Jeong, Sang Eun; Kim, Pil Joo; Madsen, Eugene L.; Jeon, Che Ok

    2015-01-01

    The communities and abundances of methanotrophs and methanogens, along with the oxygen, methane, and total organic carbon (TOC) concentrations, were investigated along a depth gradient in a flooded rice paddy. Broad patterns in vertical profiles of oxygen, methane, TOC, and microbial abundances were similar in the bulk and rhizosphere soils, though methane and TOC concentrations and 16S rRNA gene copies were clearly higher in the rhizosphere soil than in the bulk soil. Oxygen concentrations decreased sharply to below detection limits at 8 mm depth. Pyrosequencing of 16S rRNA genes showed that bacterial and archaeal communities varied according to the oxic, oxic-anoxic, and anoxic zones, indicating that oxygen is a determining factor for the distribution of bacterial and archaeal communities. Aerobic methanotrophs were maximally observed near the oxic-anoxic interface, while methane, TOC, and methanogens were highest in the rhizosphere soil at 30–200 mm depth, suggesting that methane is produced mainly from organic carbon derived from rice plants and is metabolized aerobically. The relative abundances of type I methanotrophs such as Methylococcus, Methylomonas, and Methylocaldum decreased more drastically than those of type II methanotrophs (such as Methylocystis and Methylosinus) with increasing depth. Methanosaeta and Methanoregula were predominant methanogens at all depths, and the relative abundances of Methanosaeta, Methanoregula, and Methanosphaerula, and GOM_Arc_I increased with increasing depth. Based on contrasts between absolute abundances of methanogens and methanotrophs at depths sampled across rhizosphere and bulk soils (especially millimeter-scale slices at the surface), we have identified populations of methanogens (Methanosaeta, Methanoregula, Methanocella, Methanobacterium, and Methanosphaerula), and methanotrophs (Methylosarcina, Methylococcus, Methylosinus, and unclassified Methylocystaceae) that are likely physiologically active in situ. PMID

  10. Retaining and recovering enzyme activity during degradation of TCE by methanotrophs

    SciTech Connect

    Palumbo, A.V.; Strong-Gunderson, J.M.; Carroll, S.

    1997-12-31

    To determine if compounds added during trichloroethylene (TCE) degradation could reduce the loss of enzyme activity or increase enzyme recovery, different compounds serving as energy and carbon sources, pH buffers, or free radical scavengers were tested. Formate and formic acid (reducing power and a carbon source), as well as ascorbic acid and citric acid (free radical scavengers) were added during TCE degradation at a concentration of 2 mM. A saturated solution of calcium carbonate was also tested to address pH concerns. In the presence of formate and methane, only calcium carbonate and formic acid had a beneficial effect on enzyme recovery. The calcium carbonate and formic acid both reduced the loss of enzyme activity and resulted in the highest levels of enzyme activity after recovery. 19 refs., 3 figs.

  11. The aerobic activity of metronidazole against anaerobic bacteria.

    PubMed

    Dione, Niokhor; Khelaifia, Saber; Lagier, Jean-Christophe; Raoult, Didier

    2015-05-01

    Recently, the aerobic growth of strictly anaerobic bacteria was demonstrated using antioxidants. Metronidazole is frequently used to treat infections caused by anaerobic bacteria; however, to date its antibacterial activity was only tested in anaerobic conditions. Here we aerobically tested using antioxidants the in vitro activities of metronidazole, gentamicin, doxycycline and imipenem against 10 common anaerobic and aerobic bacteria. In vitro susceptibility testing was performed by the disk diffusion method, and minimum inhibitory concentrations (MICs) were determined by Etest. Aerobic culture of the bacteria was performed at 37°C using Schaedler agar medium supplemented with 1mg/mL ascorbic acid and 0.1mg/mL glutathione; the pH was adjusted to 7.2 by 10M KOH. Growth of anaerobic bacteria cultured aerobically using antioxidants was inhibited by metronidazole after 72h of incubation at 37°C, with a mean inhibition diameter of 37.76mm and an MIC of 1μg/mL; however, strains remained non-sensitive to gentamicin. No growth inhibition of aerobic bacteria was observed after 24h of incubation at 37°C with metronidazole; however, inhibition was observed with doxycycline and imipenem used as controls. These results indicate that bacterial sensitivity to metronidazole is not related to the oxygen tension but is a result of the sensitivity of the micro-organism. In future, both culture and antibiotic susceptibility testing of strictly anaerobic bacteria will be performed in an aerobic atmosphere using antioxidants in clinical microbiology laboratories.

  12. Electroporation-Based Genetic Manipulation in Type I Methanotrophs

    PubMed Central

    Chu, Frances; Puri, Aaron W.; Fu, Yanfen; Lidstrom, Mary E.

    2016-01-01

    Methane is becoming a major candidate for a prominent carbon feedstock in the future, and the bioconversion of methane into valuable products has drawn increasing attention. To facilitate the use of methanotrophic organisms as industrial strains and accelerate our ability to metabolically engineer methanotrophs, simple and rapid genetic tools are needed. Electroporation is one such enabling tool, but to date it has not been successful in a group of methanotrophs of interest for the production of chemicals and fuels, the gammaproteobacterial (type I) methanotrophs. In this study, we developed electroporation techniques with a high transformation efficiency for three different type I methanotrophs: Methylomicrobium buryatense 5GB1C, Methylomonas sp. strain LW13, and Methylobacter tundripaludum 21/22. We further developed this technique in M. buryatense, a haloalkaliphilic aerobic methanotroph that demonstrates robust growth with a high carbon conversion efficiency and is well suited for industrial use for the bioconversion of methane. On the basis of the high transformation efficiency of M. buryatense, gene knockouts or integration of a foreign fragment into the chromosome can be easily achieved by direct electroporation of PCR-generated deletion or integration constructs. Moreover, site-specific recombination (FLP-FRT [FLP recombination target] recombination) and sacB counterselection systems were employed to perform marker-free manipulation, and two new antibiotics, zeocin and hygromycin, were validated to be antibiotic markers in this strain. Together, these tools facilitate the rapid genetic manipulation of M. buryatense and other type I methanotrophs, promoting the ability to perform fundamental research and industrial process development with these strains. PMID:26801578

  13. Methanotrophs Contribute to Peatland Nitrogen

    NASA Astrophysics Data System (ADS)

    Larmola, Tuula; Leppänen, Sanna M.; Tuittila, Eeva-Stiina; Aarva, Maija; Merilä, Päivi; Fritze, Hannu; Tiirola, Marja

    2016-04-01

    Atmospheric nitrogen (N2) fixation is potentially an important N input mechanism to peatland ecosystems, but the extent of this process may have been underestimated because of the methods traditionally used inhibit the activity of methanothrophs. We examined the linkage of methane (CH4) oxidation and N2 fixation using 15N2 technique. Dominant flark and hummock Sphagnum species were collected from twelve pristine peatlands in Siikajoki, Finland, which varied in age from 200 to 2,500 y due to the postglacial rebound. The mosses were incubated in a two-day field 15N2 and 13CH4 pulse labelling experiment and the incorporation of 15N2 and 13CH4 in biomass was measured with Isotope Ratio Mass Spectrometer. The rates of Sphagnum-associated N2 fixation (0.1-2.9 g N m-2 y-1) were up to 10 times the current N deposition rates. Methane-induced N2 fixation contributed to over 1/3 of moss-associated N2 fixation in younger stages, but was switched off in old successional stages, despite active CH4 oxidation in these stages. Both the N2 fixation rates and the methanotrophic contribution to N2 fixation during peatland succession were primarily constrained by phosphorus availability. Previously overlooked methanotrophic N contribution may explain rapid peat and N accumulation during fen stages of peatland development. Reference. Larmola T., Leppänen S.M., Tuittila E.-S, Aarva M., Merilä P., Fritze H., Tiirola M. (2014) Methanotrophy induces nitrogen fixation during peatland development. Proceedings of the National Academy of Sciences USA 111 (2): 734-739.

  14. Cardiovascular function following reduced aerobic activity

    NASA Technical Reports Server (NTRS)

    Raven, P. B.; Welch-O'Connor, R. M.; Shi, X.; Blomqvist, C. G. (Principal Investigator)

    1998-01-01

    PURPOSE: The aim of this study was to test the hypothesis that a sustained reduction of physical activity (deconditioning) would alter the cardiovascular regulatory function. METHODS: Nineteen young, healthy volunteers participated in physical deconditioning for a period of 8 wk. Before (pre) and following (post) physical deconditioning, the responses of heart rate (HR), mean arterial pressure (MAP, measured by Finapres), central venous pressure (CVP), stroke volume (SV, Doppler), and forearm blood flow (FBF, plethysmography) were determined during lower body negative pressure (LBNP). The carotid baroreflex (CBR) function was assessed using a train of pulsatile neck pressure (NP) and suction, and the aortic baroreflex control of HR was assessed during steady-state phenylephrine (PE) infusion superimposed by LBNP and NP to counteract the PE increased CVP and carotid sinus pressure, respectively. RESULTS: Active physical deconditioning significantly decreased maximal oxygen uptake (-7%) and LBNP tolerance (-13%) without a change in baseline hemodynamics. Plasma volume (-3% at P = 0.135), determined by Evans Blue dilution, and blood volume (-4% at P = 0.107) were not significantly altered. During LBNP -20 to -50 torr, there was a significantly greater drop of SV per unit decrease in CVP in the post- (14.7 +/- 1.6%/mm Hg) than predeconditioning (11.2 +/- 0.7%/mm Hg) test accompanied by a greater tachycardia. Deconditioning increased the aortic baroreflex sensitivity (pre vs post: -0.61 +/- 0.12 vs -0.84 +/- 0.14 bpm.mm-1 Hg, P = 0.009) and the slope of forearm vascular resistance (calculated from [MAP-CVP]/FBF) to CVP (-2.75 +/- 0.26 vs -4.94 +/- 0.97 PRU/mm Hg, P = 0.086). However, neither the CBR-HR (-0.28 +/- 0.03 VS -0.39 +/- 0.10 bpm.mm-1 Hg) nor the CBR-MAP (-0.37 +/- 0.16 vs -0.25 +/- 0.07 mm Hg/mm Hg) gains were statistically different between pre- and postdeconditioning. CONCLUSIONS: We concluded that the functional modification of the cardiac pressure

  15. Methanotrophic activity in the water column above shallow gas flares west of Prins Karls Forland, Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Gründger, Friederike; Svenning, Mette M.; Niemann, Helge; Silyakova, Anna; Serov, Pavel; Pavlov, Alexey K.; Granskog, Mats A.; Ferre, Bénédicte; Carroll, JoLynn

    2016-04-01

    Numerous gas flares, interpreted to be streams of methane bubbles, were discovered in shallow waters (average water depth about 90 m) on the continental shelf west of Prins Karls Forland (Western Svalbard) in the Arctic Ocean. Gas is released from the seabed to the water column and potentially transferred into the atmosphere where it acts as a potent greenhouse gas. In order to resolve the fate of dissolved methane in the water column, we carried out grid-pattern biogeochemical measurements in the study area of 30 x 15 km. Specifically, we measured concentrations of dissolved methane and microbial methane oxidation (MOx) rates at 8 water depths at 31 sampling stations and performed 16S rRNA sequencing analysis on selected samples to characterize the microbial community composition. Availability of dissolved methane is essential for the process of microbial methane oxidation. However, our measurements reveal that high concentrations of dissolved methane in the water column do not necessarily lead to high MOx rates. Our results indicated that the presence of marine methanotrophic biomass as well as dissolved organic matter is of larger importance for the process of microbial methane oxidation. For example, we found MOx hot spots with values up to 13 nmol l-1 d-1 at bottom water depth with dissolved methane concentrations less than 160 nmol l-1. In contrast, at stations where bottom methane concentration values reached 640 nmol l-1, MOx rates were less than 0.7 nmol l-1 d-1. To interpret observed interconnection between methane concentrations and MOx rates, we use vertical distributions of seawater temperature, salinity and properties of colored dissolved organic matter (CDOM). This information helps us characterize the oceanographic setting and circulation patterns in the area, which we believe has a major impact on the origin and distribution of methanotrophic microbial biomass and methane oxidation in methanerich bottom water. This study is part of the Centre for

  16. Microbial fuel cells with highly active aerobic biocathodes

    NASA Astrophysics Data System (ADS)

    Milner, Edward M.; Popescu, Dorin; Curtis, Tom; Head, Ian M.; Scott, Keith; Yu, Eileen H.

    2016-08-01

    Microbial fuel cells (MFCs), which convert organic waste to electricity, could be used to make the wastewater infrastructure more energy efficient and sustainable. However, platinum and other non-platinum chemical catalysts used for the oxygen reduction reaction (ORR) at the cathode of MFCs are unsustainable due to their high cost and long-term degradation. Aerobic biocathodes, which use microorganisms as the biocatalysts for cathode ORR, are a good alternative to chemical catalysts. In the current work, high-performing aerobic biocathodes with an onset potential for the ORR of +0.4 V vs. Ag/AgCl were enriched from activated sludge in electrochemical half-cells poised at -0.1 and + 0.2 V vs. Ag/AgCl. Gammaproteobacteria, distantly related to any known cultivated gammaproteobacterial lineage, were identified as dominant in these working electrode biofilms (23.3-44.3% of reads in 16S rRNA gene Ion Torrent libraries), and were in very low abundance in non-polarised control working electrode biofilms (0.5-0.7%). These Gammaproteobacteria were therefore most likely responsible for the high activity of biologically catalysed ORR. In MFC tests, a high-performing aerobic biocathode increased peak power 9-fold from 7 to 62 μW cm-2 in comparison to an unmodified carbon cathode, which was similar to peak power with a platinum-doped cathode at 70 μW cm-2.

  17. A temperate river estuary is a sink for methanotrophs adapted to extremes of pH, temperature and salinity

    PubMed Central

    Osborne, Kate A.; Sidgwick, Frances R.; Gray, Neil D.; Talbot, Helen M.

    2016-01-01

    Summary River Tyne (UK) estuarine sediments harbour a genetically and functionally diverse community of methane‐oxidizing bacteria (methanotrophs), the composition and activity of which were directly influenced by imposed environmental conditions (pH, salinity, temperature) that extended far beyond those found in situ. In aerobic sediment slurries methane oxidation rates were monitored together with the diversity of a functional gene marker for methanotrophs (pmoA). Under near in situ conditions (4–30°C, pH 6–8, 1–15 g l−1 NaCl), communities were enriched by sequences affiliated with M ethylobacter and M ethylomonas spp. and specifically a M ethylobacter psychrophilus‐related species at 4–21°C. More extreme conditions, namely high temperatures ≥ 40°C, high ≥ 9 and low ≤ 5 pH, and high salinities ≥ 35 g l−1 selected for putative thermophiles (M ethylocaldum), acidophiles (M ethylosoma) and haloalkaliphiles (M ethylomicrobium). The presence of these extreme methanotrophs (unlikely to be part of the active community in situ) indicates passive dispersal from surrounding environments into the estuary. PMID:26617278

  18. Methane oxidation and methanotrophs: resistance and resilience against model perturbations

    NASA Astrophysics Data System (ADS)

    Ho, A.; Frenzel, P.

    2009-04-01

    Biodiversity is claimed to be essential for ecosystem functioning. However, most experiments on biodiversity and ecosystem functioning (BEF) have been made on higher plants, while only few studies have dealt with microbial communities. Overall microbial diversity may be very high, and general functions like aerobic carbon mineralization are assumed to be supported by highly redundant communities. Therefore, we focused on methane oxidation, a microbial process of global importance mitigating methane emissions from wetland, rice fields, and landfills. We used a rice paddy as our model system, where >90% of potentially emitted methane may be oxidized in the oxic surface layer. This community is presumed to consist of 10-20 taxa more or less equivalent to species. We focused on the ability of methanotrophs to recover from a disturbance causing a significant die-off of all microbial populations. This was simulated by mixing native with sterile soil in two ratios (1:4 and 1:40). Microcosms were incubated and the temporal shift of the methanotrophic communities was followed by pmoA-based Terminal Restriction Length Polymorphism (T-RFLP), qPCR, and a pmoA-based diagnostic microarray. We consistently observed distinctive temporal shifts between Methylocystaceaea and Methylococcacea, a rapid population growth leading to the same or even higher cell numbers as in microcosms made from native soil alone, but no effect on the amount of methane oxidized. The ratio of different methanotrophs changed with treatment, while the number of taxa stayed nearly the same. Overall, methanotrophs showed a remarkable resilience compensating for die-offs. It has to be noted, however, that our experiment focused on methanotrophs adapted to and living at high methane fluxes. Quite different, methanotrophs living in upland soils do not mitigate methane emissions, but are the only biological sink to atmospheric methane. These microbes are severely substrate limited, and will be much more

  19. Methane monooxygenase from Methylosinus trichosporium OB3b. Purification and properties of a three-component system with high specific activity from a type II methanotroph.

    PubMed

    Fox, B G; Froland, W A; Dege, J E; Lipscomb, J D

    1989-06-15

    Methane monooxygenase has been purified from the Type II methanotroph Methylosinus trichosporium OB3b. As observed for methane monooxygenase isolated from Type I methanotrophs, three protein components are required: a 39.7-kDa NADH reductase containing 1 mol each of FAD and a [2Fe-2S] cluster, a 15.8-kDa protein factor termed component B that contains no metals or cofactors, and a 245-kDa hydroxylase which appears to contain an oxo- or hydroxo-bridged binuclear iron cluster. Through the use of stabilizing reagents, the hydroxylase is obtained in high yield and exhibits a specific activity 8-25-fold greater than reported for previous preparations. The component B and reductase exhibit 1.5- and 4-fold greater specific activity, respectively. Quantitation of the hydroxylase oxo-bridged cluster using EPR and Mössbauer spectroscopies reveals that the highest specific activity preparations (approximately 1700 nmol/min/mg) contain approximately 2 clusters/mol. In contrast, hydroxylase preparations exhibiting a wide range of specific activities below 500 nmol/min/mg contain approximately 1 cluster/mol on average. Efficient turnover coupled to NADH oxidation requires all three protein components. However, both alkanes and alkenes are hydroxylated by the chemically reduced hydroxylase under single turnover conditions in the absence of component B and the reductase. Neither of these components catalyzes hydroxylation individually nor do they significantly affect the yield of hydroxylated product from the chemically reduced hydroxylase. Hydroxylase reduced only to the mixed valent [Fe(II).Fe(III)] state is unreactive toward O2 and yields little hydroxylated product on single turnover. This suggests that the catalytically active species is the fully reduced form. The data presented here provide the first evidence based on catalysis that the site of the monooxygenation reaction is located on the hydroxylase. It thus appears likely that the oxo-bridged iron cluster is capable of

  20. Ultrastructure of the denitrifying methanotroph "Candidatus Methylomirabilis oxyfera," a novel polygon-shaped bacterium.

    PubMed

    Wu, Ming L; van Teeseling, Muriel C F; Willems, Marieke J R; van Donselaar, Elly G; Klingl, Andreas; Rachel, Reinhard; Geerts, Willie J C; Jetten, Mike S M; Strous, Marc; van Niftrik, Laura

    2012-01-01

    "Candidatus Methylomirabilis oxyfera" is a newly discovered denitrifying methanotroph that is unrelated to previously known methanotrophs. This bacterium is a member of the NC10 phylum and couples methane oxidation to denitrification through a newly discovered intra-aerobic pathway. In the present study, we report the first ultrastructural study of "Ca. Methylomirabilis oxyfera" using scanning electron microscopy, transmission electron microscopy, and electron tomography in combination with different sample preparation methods. We observed that "Ca. Methylomirabilis oxyfera" cells possess an atypical polygonal shape that is distinct from other bacterial shapes described so far. Also, an additional layer was observed as the outermost sheath, which might represent a (glyco)protein surface layer. Further, intracytoplasmic membranes, which are a common feature among proteobacterial methanotrophs, were never observed under the current growth conditions. Our results indicate that "Ca. Methylomirabilis oxyfera" is ultrastructurally distinct from other bacteria by its atypical cell shape and from the classical proteobacterial methanotrophs by its apparent lack of intracytoplasmic membranes.

  1. Progressive hypoxia decouples activity and aerobic performance of skate embryos

    PubMed Central

    Di Santo, Valentina; Tran, Anna H.; Svendsen, Jon C.

    2016-01-01

    Although fish population size is strongly affected by survival during embryonic stages, our understanding of physiological responses to environmental stressors is based primarily on studies of post-hatch fishes. Embryonic responses to acute exposure to changes in abiotic conditions, including increase in hypoxia, could be particularly important in species exhibiting long developmental time, as embryos are unable to select a different environment behaviourally. Given that oxygen is key to metabolic processes in fishes and aquatic hypoxia is becoming more severe and frequent worldwide, organisms are expected to reduce their aerobic performance. Here, we examined the metabolic and behavioural responses of embryos of a benthic elasmobranch fish, the little skate (Leucoraja erinacea), to acute progressive hypoxia, by measuring oxygen consumption and movement (tail-beat) rates inside the egg case. Oxygen consumption rates were not significantly affected by ambient oxygen levels until reaching 45% air saturation (critical oxygen saturation, Scrit). Below Scrit, oxygen consumption rates declined rapidly, revealing an oxygen conformity response. Surprisingly, we observed a decoupling of aerobic performance and activity, as tail-beat rates increased, rather than matching the declining metabolic rates, at air saturation levels of 55% and below. These results suggest a significantly divergent response at the physiological and behavioural levels. While skate embryos depressed their metabolic rates in response to progressive hypoxia, they increased water circulation inside the egg case, presumably to restore normoxic conditions, until activity ceased abruptly around 9.8% air saturation. PMID:27293746

  2. Aerobic glycolysis tunes YAP/TAZ transcriptional activity

    PubMed Central

    Enzo, Elena; Santinon, Giulia; Pocaterra, Arianna; Aragona, Mariaceleste; Bresolin, Silvia; Forcato, Mattia; Grifoni, Daniela; Pession, Annalisa; Zanconato, Francesca; Guzzo, Giulia; Bicciato, Silvio; Dupont, Sirio

    2015-01-01

    Increased glucose metabolism and reprogramming toward aerobic glycolysis are a hallmark of cancer cells, meeting their metabolic needs for sustained cell proliferation. Metabolic reprogramming is usually considered as a downstream consequence of tumor development and oncogene activation; growing evidence indicates, however, that metabolism on its turn can support oncogenic signaling to foster tumor malignancy. Here, we explored how glucose metabolism regulates gene transcription and found an unexpected link with YAP/TAZ, key transcription factors regulating organ growth, tumor cell proliferation and aggressiveness. When cells actively incorporate glucose and route it through glycolysis, YAP/TAZ are fully active; when glucose metabolism is blocked, or glycolysis is reduced, YAP/TAZ transcriptional activity is decreased. Accordingly, glycolysis is required to sustain YAP/TAZ pro-tumorigenic functions, and YAP/TAZ are required for the full deployment of glucose growth-promoting activity. Mechanistically we found that phosphofructokinase (PFK1), the enzyme regulating the first committed step of glycolysis, binds the YAP/TAZ transcriptional cofactors TEADs and promotes their functional and biochemical cooperation with YAP/TAZ. Strikingly, this regulation is conserved in Drosophila, where phosphofructokinase is required for tissue overgrowth promoted by Yki, the fly homologue of YAP. Moreover, gene expression regulated by glucose metabolism in breast cancer cells is strongly associated in a large dataset of primary human mammary tumors with YAP/TAZ activation and with the progression toward more advanced and malignant stages. These findings suggest that aerobic glycolysis endows cancer cells with particular metabolic properties and at the same time sustains transcription factors with potent pro-tumorigenic activities such as YAP/TAZ. PMID:25796446

  3. Aerobic glycolysis tunes YAP/TAZ transcriptional activity.

    PubMed

    Enzo, Elena; Santinon, Giulia; Pocaterra, Arianna; Aragona, Mariaceleste; Bresolin, Silvia; Forcato, Mattia; Grifoni, Daniela; Pession, Annalisa; Zanconato, Francesca; Guzzo, Giulia; Bicciato, Silvio; Dupont, Sirio

    2015-05-12

    Increased glucose metabolism and reprogramming toward aerobic glycolysis are a hallmark of cancer cells, meeting their metabolic needs for sustained cell proliferation. Metabolic reprogramming is usually considered as a downstream consequence of tumor development and oncogene activation; growing evidence indicates, however, that metabolism on its turn can support oncogenic signaling to foster tumor malignancy. Here, we explored how glucose metabolism regulates gene transcription and found an unexpected link with YAP/TAZ, key transcription factors regulating organ growth, tumor cell proliferation and aggressiveness. When cells actively incorporate glucose and route it through glycolysis, YAP/TAZ are fully active; when glucose metabolism is blocked, or glycolysis is reduced, YAP/TAZ transcriptional activity is decreased. Accordingly, glycolysis is required to sustain YAP/TAZ pro-tumorigenic functions, and YAP/TAZ are required for the full deployment of glucose growth-promoting activity. Mechanistically we found that phosphofructokinase (PFK1), the enzyme regulating the first committed step of glycolysis, binds the YAP/TAZ transcriptional cofactors TEADs and promotes their functional and biochemical cooperation with YAP/TAZ. Strikingly, this regulation is conserved in Drosophila, where phosphofructokinase is required for tissue overgrowth promoted by Yki, the fly homologue of YAP. Moreover, gene expression regulated by glucose metabolism in breast cancer cells is strongly associated in a large dataset of primary human mammary tumors with YAP/TAZ activation and with the progression toward more advanced and malignant stages. These findings suggest that aerobic glycolysis endows cancer cells with particular metabolic properties and at the same time sustains transcription factors with potent pro-tumorigenic activities such as YAP/TAZ.

  4. Enrichment culture and identification of endophytic methanotrophs isolated from peatland plants.

    PubMed

    Stępniewska, Zofia; Goraj, Weronika; Kuźniar, Agnieszka; Łopacka, Natalia; Małysza, Magdalena

    2017-03-09

    Aerobic methane-oxidizing bacteria (MOB) are an environmentally significant group of microorganisms due to their role in the global carbon cycle. Research conducted over the past few decades has increased the interest in discovering novel genera of methane-degrading bacteria, which efficiently utilize methane and decrease the global warming effect. Moreover, methanotrophs have more promising applications in environmental bioengineering, biotechnology, and pharmacy. The investigations were undertaken to recognize the variety of endophytic methanotrophic bacteria associated with Carex nigra, Vaccinium oxycoccus, and Eriophorum vaginatum originating from Moszne peatland (East Poland). Methanotrophic bacteria were isolated from plants by adding sterile fragments of different parts of plants (roots and stems) to agar mineral medium (nitrate mineral salts (NMS)) and incubated at different methane values (1-20% CH4). Single colonies were streaked on new NMS agar media and, after incubation, transferred to liquid NMS medium. Bacterial growth dynamics in the culture solution was studied by optical density-OD600 and methane consumption. Changes in the methane concentration during incubation were controlled by the gas chromatography technique. Characterization of methanotrophs was made by fluorescence in situ hybridization (FISH) with Mg705 and Mg84 for type I methanotrophs and Ma450 for type II methanotrophs. Identification of endophytes was performed after 16S ribosomal RNA (rRNA) and mmoX gene amplification. Our study confirmed the presence of both types of methanotrophic bacteria (types I and II) with the predominance of type I methanotrophs. Among cultivable methanotrophs, there were different strains of the genus Methylomonas and Methylosinus. Furthermore, we determined the potential of the examined bacteria for methane oxidation, which ranged from 0.463 ± 0.067 to 5.928 ± 0.169 μmol/L CH4/mL/day.

  5. 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.

  6. Degradation of methyl bromide by methanotrophic bacteria in cell suspensions and soils

    USGS Publications Warehouse

    Oremland, R.S.; Miller, L.G.; Culbertson, C.W.; Connell, T.L.; Jahnke, L.

    1994-01-01

    Cell suspensions of Methylococcus capsulatus mineralized methyl bromide (MeBr), as evidenced by its removal from the gas phase, the quantitative recovery of Br- in the spent medium, and the production of 14CO2 from [14C]MeBr. Methyl fluoride (MeF) inhibited oxidation of methane as well as that of [14C]MeBr. The rate of MeBr consumption by cells varied inversely with the supply of methane, which suggested a competitive relationship between these two substrates. However, MeBr did not support growth of the methanotroph. In soils exposed to high levels (10,000 ppm) of MeBr, methane oxidation was completely inhibited. At this concentration, MeBr removal rates were equivalent in killed and live controls, which indicated a chemical rather than biological removal reaction. At lower concentrations (1,000 ppm) of MeBr, methanotrophs were active and MeBr consumption rates were 10-fold higher in live controls than in killed controls. Soils exposed to trace levels (10 ppm) of MeBr demonstrated complete consumption within 5 h of incubation, while controls inhibited with MeF or incubated without O2 had 50% lower removal rates. Aerobic soils oxidized [14C]MeBr to 14CO2, and MeF inhibited oxidation by 72%. Field experiments demonstrated slightly lower MeBr removal rates in chambers containing MeF than in chambers lacking MeF. Collectively, these results show that soil methanotrophic bacteria, as well as other microbes, can degrade MeBr present in the environment.

  7. Trace-gas metabolic versatility of the facultative methanotroph Methylocella silvestris.

    PubMed

    Crombie, Andrew T; Murrell, J Colin

    2014-06-05

    The climate-active gas methane is generated both by biological processes and by thermogenic decomposition of fossil organic material, which forms methane and short-chain alkanes, principally ethane, propane and butane. In addition to natural sources, environments are exposed to anthropogenic inputs of all these gases from oil and gas extraction and distribution. The gases provide carbon and/or energy for a diverse range of microorganisms that can metabolize them in both anoxic and oxic zones. Aerobic methanotrophs, which can assimilate methane, have been considered to be entirely distinct from utilizers of short-chain alkanes, and studies of environments exposed to mixtures of methane and multi-carbon alkanes have assumed that disparate groups of microorganisms are responsible for the metabolism of these gases. Here we describe the mechanism by which a single bacterial strain, Methylocella silvestris, can use methane or propane as a carbon and energy source, documenting a methanotroph that can utilize a short-chain alkane as an alternative to methane. Furthermore, during growth on a mixture of these gases, efficient consumption of both gases occurred at the same time. Two soluble di-iron centre monooxygenase (SDIMO) gene clusters were identified and were found to be differentially expressed during bacterial growth on these gases, although both were required for efficient propane utilization. This report of a methanotroph expressing an additional SDIMO that seems to be uniquely involved in short-chain alkane metabolism suggests that such metabolic flexibility may be important in many environments where methane and short-chain alkanes co-occur.

  8. Denitrification kinetics in anoxic/aerobic activated sludge systems

    SciTech Connect

    Horne, G.M.

    1998-12-11

    Nitrogen removal needs at municipal wastewater treatment plants (WWTPs) have increased due to greater concerns about eutrophication and increased interest in reuse of treated municipal effluents. Biological processes are the most cost-effective method for nitrogen removal. Biological nitrogen removal is accomplished in two distinctly different processes by the conversion of nitrogen in the wastewater from organic nitrogen and ammonia to nitrate, followed by reduction of the nitrate to nitrogen gas. Nitrate production occurs in an aerobic activated sludge treatment zone during a process called nitrification. The nitrate is then converted through a series of intermediate steps to nitrogen gas in an anoxic zone (an anaerobic condition with nitrate present) during a process called denitrification, effectively removing the nitrogen from the wastewater. Many different WWTP designs have been developed to incorporate these two conditions for nitrogen removal.

  9. Aerobic degradation of sulfanilic acid using activated sludge.

    PubMed

    Chen, Gang; Cheng, Ka Yu; Ginige, Maneesha P; Kaksonen, Anna H

    2012-01-01

    This paper evaluates the aerobic degradation of sulfanilic acid (SA) by an acclimatized activated sludge. The sludge was enriched for over three months with SA (>500 mg/L) as the sole carbon and energy source and dissolved oxygen (DO, >5mg/L) as the primary electron acceptor. Effects of aeration rate (0-1.74 L/min), DO concentration (0-7 mg/L) and initial SA concentration (104-1085 mg/L) on SA biodegradation were quantified. A modified Haldane substrate inhibition model was used to obtain kinetic parameters of SA biodegradation and oxygen uptake rate (OUR). Positive linear correlations were obtained between OUR and SA degradation rate (R(2)≥ 0.91). Over time, the culture consumed more oxygen per SA degraded, signifying a gradual improvement in SA mineralization (mass ratio of O(2): SA at day 30, 60 and 120 were 0.44, 0.51 and 0.78, respectively). The concomitant release of near stoichiometric quantity of sulphate (3.2 mmol SO(4)(2-) released from 3.3 mmol SA) and the high chemical oxygen demand (COD) removal efficacy (97.1%) indicated that the enriched microbial consortia could drive the overall SA oxidation close to a complete mineralization. In contrast to other pure-culture systems, the ammonium released from the SA oxidation was predominately converted into nitrate, revealing the presence of ammonium-oxidizing bacteria (AOB) in the mixed culture. No apparent inhibitory effect of SA on the nitrification was noted. This work also indicates that aerobic SA biodegradation could be monitored by real-time DO measurement.

  10. 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

  11. Selective grazing of methanotrophs by protozoa in a rice field soil.

    PubMed

    Murase, Jun; Frenzel, Peter

    2008-09-01

    Biological methane oxidation is a key process in the methane cycle of wetland ecosystems. The methanotrophic biomass may be grazed by protozoa, thus linking the methane cycle to the soil microbial food web. In the present study, the edibility of different methanotrophs for soil protozoa was compared. The number of methanotroph-feeding protozoa in a rice field soil was estimated by determining the most-probable number (MPN) using methanotrophs as food bacteria; naked amoebae and flagellates were the dominant protozoa. Among ten methanotrophic strains examined as a food source, seven yielded a number of protozoa comparable with the yield with Escherichia coli [10(4) MPN (g soil dry weight)(-1)], and three out of four Methylocystis spp. yielded significantly fewer numbers [10(2)-10(3) MPN (g soil dry weight)(-1)]. The lower edibility of the Methylocystis spp. was not explained either by their growth phase or by harmful effects on protozoa. Incubation of the soil under methane resulted in a higher number of protozoa actively grazing on methanotrophs, especially on the less-edible group. Protozoa isolated from the soil demonstrated a grazing preference on the different methanotrophs consistent with the results of MPN counts. The results indicate that selective grazing by protozoa may be a biological factor affecting the methanotrophic community in a wetland soil.

  12. Detection of autotrophic verrucomicrobial methanotrophs in a geothermal environment using stable isotope probing.

    PubMed

    Sharp, Christine E; Stott, Matthew B; Dunfield, Peter F

    2012-01-01

    Genomic analysis of the methanotrophic verrucomicrobium "Methylacidiphilum infernorum" strain V4 has shown that most pathways conferring its methanotrophic lifestyle are similar to those found in proteobacterial methanotrophs. However, due to the large sequence divergence of its methane monooxygenase-encoding genes (pmo), "universal" pmoA polymerase chain reaction (PCR) primers do not target these bacteria. Unlike proteobacterial methanotrophs, "Methylacidiphilum" fixes carbon autotrophically, and uses methane only for energy generation. As a result, techniques used to detect methanotrophs in the environment such as (13)CH(4)-stable isotope probing (SIP) and pmoA-targeted PCR do not detect verrucomicrobial methanotrophs, and they may have been overlooked in previous environmental studies. We developed a modified SIP technique to identify active methanotrophic Verrucomicrobia in the environment by labeling with (13)CO(2) and (13)CH(4), individually and in combination. Testing the protocol in "M. infernorum" strain V4 resulted in assimilation of (13)CO(2) but not (13)CH(4), verifying its autotrophic lifestyle. To specifically detect methanotrophs (as opposed to other autotrophs) via (13)CO(2)-SIP, a quantitative PCR (qPCR) assay specific for verrucomicrobial-pmoA genes was developed and used in combination with SIP. Incubation of an acidic, high-temperature geothermal soil with (13)CH(4) + (12)CO(2) caused little shift in the density distribution of verrucomicrobial-pmoA genes relative to controls. However, labeling with (13)CO(2) in combination with (12)CH(4) or (13)CH(4) induced a strong shift in the distribution of verrucomicrobial-pmoA genes towards the heavy DNA fractions. The modified SIP technique demonstrated that the primary methanotrophs active in the soil were autotrophs and belonged to the Verrucomicrobia. This is the first demonstration of autotrophic, non-proteobacterial methanotrophy in situ, and provides a tool to detect verrucomicrobial methanotrophs

  13. Detection of autotrophic verrucomicrobial methanotrophs in a geothermal environment using stable isotope probing

    PubMed Central

    Sharp, Christine E.; Stott, Matthew B.; Dunfield, Peter F.

    2012-01-01

    Genomic analysis of the methanotrophic verrucomicrobium “Methylacidiphilum infernorum” strain V4 has shown that most pathways conferring its methanotrophic lifestyle are similar to those found in proteobacterial methanotrophs. However, due to the large sequence divergence of its methane monooxygenase-encoding genes (pmo), “universal” pmoA polymerase chain reaction (PCR) primers do not target these bacteria. Unlike proteobacterial methanotrophs, “Methylacidiphilum” fixes carbon autotrophically, and uses methane only for energy generation. As a result, techniques used to detect methanotrophs in the environment such as 13CH4-stable isotope probing (SIP) and pmoA-targeted PCR do not detect verrucomicrobial methanotrophs, and they may have been overlooked in previous environmental studies. We developed a modified SIP technique to identify active methanotrophic Verrucomicrobia in the environment by labeling with 13CO2 and 13CH4, individually and in combination. Testing the protocol in “M. infernorum” strain V4 resulted in assimilation of 13CO2 but not 13CH4, verifying its autotrophic lifestyle. To specifically detect methanotrophs (as opposed to other autotrophs) via 13CO2-SIP, a quantitative PCR (qPCR) assay specific for verrucomicrobial-pmoA genes was developed and used in combination with SIP. Incubation of an acidic, high-temperature geothermal soil with 13CH4 + 12CO2 caused little shift in the density distribution of verrucomicrobial-pmoA genes relative to controls. However, labeling with 13CO2 in combination with 12CH4 or 13CH4 induced a strong shift in the distribution of verrucomicrobial-pmoA genes towards the heavy DNA fractions. The modified SIP technique demonstrated that the primary methanotrophs active in the soil were autotrophs and belonged to the Verrucomicrobia. This is the first demonstration of autotrophic, non-proteobacterial methanotrophy in situ, and provides a tool to detect verrucomicrobial methanotrophs in other ecosystems. PMID

  14. [Isolation and identification of electrochemically active microorganism from micro-aerobic environment].

    PubMed

    Wu, Song; Xiao, Yong; Zheng, Zhi-Yong; Zheng, Yue; Yang, Zhao-Hui; Zhao, Feng

    2014-10-01

    Extracellular electron transfer of electrochemically active microorganism plays vital role in biogeochemical cycling of metals and carbon and in biosynthesis of bioenergy. Compared to anaerobic anode, micro-aerobic anode captures more energy from microbial fuel cell. However, most of previous researches focused on functioning bacteria in anaerobic anode, functioning bacteria in micro-aerobic anode was rarely studied. Herein, we used the traditional aerobic screening technology to isolate functioning bacteria from a micro-aerobic anode. Three pure cultures Aeromonas sp. WS-XY2, Citrobacter sp. WS-XY3 and Bacterium strain WS-XY4 were obtained. WS-XY2 and WS-XY3 were belonged to Proteobacteria, whereas WS-XY4 was possibly a new species. Cyclic voltammetry and chronoamperometry analysis demonstrated all of them showed the electrochemical activity by direct extracellular electron transfer, and micro-aerobic anode could select bacteria that have similar electrochemical activity to proliferate on the anode. We further conclude that functioning bacteria in micro-aerobic anode are more efficient than that of anaerobic anode may be the reason that micro-aerobic anode has better performance than anaerobic anode. Therefore, a thorough study of functioning bacteria in micro-aerobic anode will significantly promote the energy recovery from microbial fuel cell.

  15. Influence of elevated ozone concentration on methanotrophic bacterial communities in soil under field condition

    NASA Astrophysics Data System (ADS)

    Huang, Y. Z.; Zhong, M.

    2015-05-01

    The open top chamber (OTC) method was used in combination with real-time quantitative PCR and terminal restriction fragment length polymorphism (T-RFLP) techniques in the wheat field to study the influence of different levels of O3 concentrations (ambient air filtered by activated carbons, 40 ppb, 80 ppb and 120 ppb) on the quantity and community structure of methanotrophic bacteria. O3 stress can influence the potential methane oxidation rate (PMOR) and potential methane production rate (PMPR) in the farmland soil. O3 treatment of 40 ppb improved significantly the 16S rRNA gene copy number in the total methanotrophic bacteria pmoA, and type I and type II methanotrophic bacteria in the soil depth of 0-20 cm. When the O3 concentration reached 120 ppb, the 16S rRNA gene copy number in the total methanotrophic bacteria pmoA and type I methanotrophic bacteria decreased significantly as compared to the control treatment in 10-20 cm layer. The 16s rRNA gene copy number of total methanotrophic bacteria pmoA and type I and type II methanotrophic bacteria were influenced by different O3 concentration and soil depth. The T-RFLP analysis indicated that O3 stress influenced significantly the community structure of the methanotrophic bacteria in soil, causing potential threat to the diversity of methanotrophic bacteria. It seems to imply that the rise of O3 concentration could produce an impact on the carbon cycling and the methane emission of the wheat field soil by changing the community structure and diversity of methanotrophic bacteria, which then influences the global climate change.

  16. Aquatic plant surface as a niche for methanotrophs.

    PubMed

    Yoshida, Naoko; Iguchi, Hiroyuki; Yurimoto, Hiroya; Murakami, Akio; Sakai, Yasuyoshi

    2014-01-01

    This study investigated the potential local CH4 sink in various plant parts as a boundary environment of CH4 emission and consumption. By comparing CH4 consumption activities in cultures inoculated with parts from 39 plant species, we observed significantly higher consumption of CH4 associated with aquatic plants than other emergent plant parts such as woody plant leaves, macrophytic marine algae, and sea grass. In situ activity of CH4 consumption by methanotrophs associated with different species of aquatic plants was in the range of 3.7-37 μmol·h(-1)·g(-1) dry weight, which was ca 5.7-370-fold higher than epiphytic CH4 consumption in submerged parts of emergent plants. The qPCR-estimated copy numbers of the particulate methane monooxygenase-encoding gene pmoA were variable among the aquatic plants and ranged in the order of 10(5)-10(7) copies·g(-1) dry weight, which correlated with the observed CH4 consumption activities. Phylogenetic identification of methanotrophs on aquatic plants based on the pmoA sequence analysis revealed a predominance of diverse gammaproteobacterial type-I methanotrophs, including a phylotype of a possible plant-associated methanotroph with the closest identity (86-89%) to Methylocaldum gracile.

  17. Aquatic plant surface as a niche for methanotrophs

    PubMed Central

    Yoshida, Naoko; Iguchi, Hiroyuki; Yurimoto, Hiroya; Murakami, Akio; Sakai, Yasuyoshi

    2014-01-01

    This study investigated the potential local CH4 sink in various plant parts as a boundary environment of CH4 emission and consumption. By comparing CH4 consumption activities in cultures inoculated with parts from 39 plant species, we observed significantly higher consumption of CH4 associated with aquatic plants than other emergent plant parts such as woody plant leaves, macrophytic marine algae, and sea grass. In situ activity of CH4 consumption by methanotrophs associated with different species of aquatic plants was in the range of 3.7–37 μmol·h−1·g−1 dry weight, which was ca 5.7–370-fold higher than epiphytic CH4 consumption in submerged parts of emergent plants. The qPCR-estimated copy numbers of the particulate methane monooxygenase-encoding gene pmoA were variable among the aquatic plants and ranged in the order of 105–107 copies·g−1 dry weight, which correlated with the observed CH4 consumption activities. Phylogenetic identification of methanotrophs on aquatic plants based on the pmoA sequence analysis revealed a predominance of diverse gammaproteobacterial type-I methanotrophs, including a phylotype of a possible plant-associated methanotroph with the closest identity (86–89%) to Methylocaldum gracile. PMID:24550901

  18. The effect of nitrite on aerobic phosphate uptake and denitrifying activity of phosphate-accumulating organisms.

    PubMed

    Yoshida, Y; Takahashi, K; Saito, T; Tanaka, K

    2006-01-01

    An anaerobic/aerobic/anoxic/aerobic sequencing batch reactor (SBR) was operated with municipal wastewater to investigate the effect of nitrite on biological phosphorus removal (BPR). When nitrite accumulated, aerobic phosphate uptake activity significantly decreased and, in case of hard exposure to nitrite, BPR severely deteriorated. The interesting observation was that the relative anoxic activity of phosphate accumulating organisms (PAOs) increased after nitrite exposure. Moreover batch tests of aerobic phosphate uptake in the presence/absence of nitrite indicated that PAOs with the higher relative anoxic activity are less sensitive to nitrite exposure. From these results, we concluded that BPR is sensitive to nitrite exposure, but BPR containing PAOs with the higher relative anoxic activity is possibly more stable against nitrite than BPR containing PAOs with the lower relative anoxic activity.

  19. Declining physical capacity but maintained aerobic activity in early Alzheimer's disease.

    PubMed

    Cedervall, Ylva; Kilander, Lena; Aberg, Anna Cristina

    2012-05-01

    The longitudinal influences on physical capacity and habitual aerobic activity level in the early stages of Alzheimer's disease (AD) are unclear. Therefore, changes in physical capacity and aerobic activity level were evaluated. Twenty-five individuals with AD were assessed annually for 2 years, by 10-m walk test, 6-minute walk test, and timed up-and-go (TUG) single/dual tasks. Habitual aerobic activity was assessed by diary registrations. The AD group showed a lower physical capacity than controls at baseline but comparable levels of aerobic activity. During the follow-up period, physical capacity declined in the AD group, but the aerobic activity levels changed only marginally. Our results show that in the early stages of AD, people are capable of maintaining health-promoting aerobic activity levels, despite a decline in their physical capacity. Additionally, it appears that cognitive dysfunction contributes to an impaired physical capacity. The TUG tasks might, therefore, be useful for detecting early signs of cognitive impairment.

  20. Anaerobic methanotrophic community of a 5346-m-deep vesicomyid clam colony in the Japan Trench.

    PubMed

    Felden, J; Ruff, S E; Ertefai, T; Inagaki, F; Hinrichs, K-U; Wenzhöfer, F

    2014-05-01

    Vesicomyidae clams harbor sulfide-oxidizing endosymbionts and are typical members of cold seep communities where active venting of fluids and gases takes place. We investigated the central biogeochemical processes that supported a vesicomyid clam colony as part of a locally restricted seep community in the Japan Trench at 5346 m water depth, one of the deepest seep settings studied to date. An integrated approach of biogeochemical and molecular ecological techniques was used combining in situ and ex situ measurements. In sediment of the clam colony, low sulfate reduction rates (maximum 128 nmol mL(-1) day(-1)) were coupled to the anaerobic oxidation of methane. They were observed over a depth range of 15 cm, caused by active transport of sulfate due to bioturbation of the vesicomyid clams. A distinct separation between the seep and the surrounding seafloor was shown by steep horizontal geochemical gradients and pronounced microbial community shifts. The sediment below the clam colony was dominated by anaerobic methanotrophic archaea (ANME-2c) and sulfate-reducing Desulfobulbaceae (SEEP-SRB-3, SEEP-SRB-4). Aerobic methanotrophic bacteria were not detected in the sediment, and the oxidation of sulfide seemed to be carried out chemolithoautotrophically by Sulfurovum species. Thus, major redox processes were mediated by distinct subgroups of seep-related microorganisms that might have been selected by this specific abyssal seep environment. Fluid flow and microbial activity were low but sufficient to support the clam community over decades and to build up high biomasses. Hence, the clams and their microbial communities adapted successfully to a low-energy regime and may represent widespread chemosynthetic communities in the Japan Trench. In this regard, they contributed to the restricted deep-sea trench biodiversity as well as to the organic carbon availability, also for non-seep organisms, in such oligotrophic benthic environment of the dark deep ocean.

  1. Anaerobic methanotrophic community of a 5346-m-deep vesicomyid clam colony in the Japan Trench

    PubMed Central

    Felden, J; Ruff, S E; Ertefai, T; Inagaki, F; Hinrichs, K-U; Wenzhöfer, F

    2014-01-01

    Vesicomyidae clams harbor sulfide-oxidizing endosymbionts and are typical members of cold seep communities where active venting of fluids and gases takes place. We investigated the central biogeochemical processes that supported a vesicomyid clam colony as part of a locally restricted seep community in the Japan Trench at 5346 m water depth, one of the deepest seep settings studied to date. An integrated approach of biogeochemical and molecular ecological techniques was used combining in situ and ex situ measurements. In sediment of the clam colony, low sulfate reduction rates (maximum 128 nmol mL−1 day−1) were coupled to the anaerobic oxidation of methane. They were observed over a depth range of 15 cm, caused by active transport of sulfate due to bioturbation of the vesicomyid clams. A distinct separation between the seep and the surrounding seafloor was shown by steep horizontal geochemical gradients and pronounced microbial community shifts. The sediment below the clam colony was dominated by anaerobic methanotrophic archaea (ANME-2c) and sulfate-reducing Desulfobulbaceae (SEEP-SRB-3, SEEP-SRB-4). Aerobic methanotrophic bacteria were not detected in the sediment, and the oxidation of sulfide seemed to be carried out chemolithoautotrophically by Sulfurovum species. Thus, major redox processes were mediated by distinct subgroups of seep-related microorganisms that might have been selected by this specific abyssal seep environment. Fluid flow and microbial activity were low but sufficient to support the clam community over decades and to build up high biomasses. Hence, the clams and their microbial communities adapted successfully to a low-energy regime and may represent widespread chemosynthetic communities in the Japan Trench. In this regard, they contributed to the restricted deep-sea trench biodiversity as well as to the organic carbon availability, also for non-seep organisms, in such oligotrophic benthic environment of the dark deep ocean. PMID

  2. High Throughput Sequencing to Detect Differences in Methanotrophic Methylococcaceae and Methylocystaceae in Surface Peat, Forest Soil, and Sphagnum Moss in Cranesville Swamp Preserve, West Virginia, USA.

    PubMed

    Lau, Evan; Iv, Edward J Nolan; Dillard, Zachary W; Dague, Ryan D; Semple, Amanda L; Wentzell, Wendi L

    2015-04-02

    Northern temperate forest soils and Sphagnum-dominated peatlands are a major source and sink of methane. In these ecosystems, methane is mainly oxidized by aerobic methanotrophic bacteria, which are typically found in aerated forest soils, surface peat, and Sphagnum moss. We contrasted methanotrophic bacterial diversity and abundances from the (i) organic horizon of forest soil; (ii) surface peat; and (iii) submerged Sphagnum moss from Cranesville Swamp Preserve, West Virginia, using multiplex sequencing of bacterial 16S rRNA (V3 region) gene amplicons. From ~1 million reads, >50,000 unique OTUs (Operational Taxonomic Units), 29 and 34 unique sequences were detected in the Methylococcaceae and Methylocystaceae, respectively, and 24 potential methanotrophs in the Beijerinckiaceae were also identified. Methylacidiphilum-like methanotrophs were not detected. Proteobacterial methanotrophic bacteria constitute <2% of microbiota in these environments, with the Methylocystaceae one to two orders of magnitude more abundant than the Methylococcaceae in all environments sampled. The Methylococcaceae are also less diverse in forest soil compared to the other two habitats. Nonmetric multidimensional scaling analyses indicated that the majority of methanotrophs from the Methylococcaceae and Methylocystaceae tend to occur in one habitat only (peat or Sphagnum moss) or co-occurred in both Sphagnum moss and peat. This study provides insights into the structure of methanotrophic communities in relationship to habitat type, and suggests that peat and Sphagnum moss can influence methanotroph community structure and biogeography.

  3. High Throughput Sequencing to Detect Differences in Methanotrophic Methylococcaceae and Methylocystaceae in Surface Peat, Forest Soil, and Sphagnum Moss in Cranesville Swamp Preserve, West Virginia, USA

    PubMed Central

    Lau, Evan; Nolan, Edward J.; Dillard, Zachary W.; Dague, Ryan D.; Semple, Amanda L.; Wentzell, Wendi L.

    2015-01-01

    Northern temperate forest soils and Sphagnum-dominated peatlands are a major source and sink of methane. In these ecosystems, methane is mainly oxidized by aerobic methanotrophic bacteria, which are typically found in aerated forest soils, surface peat, and Sphagnum moss. We contrasted methanotrophic bacterial diversity and abundances from the (i) organic horizon of forest soil; (ii) surface peat; and (iii) submerged Sphagnum moss from Cranesville Swamp Preserve, West Virginia, using multiplex sequencing of bacterial 16S rRNA (V3 region) gene amplicons. From ~1 million reads, >50,000 unique OTUs (Operational Taxonomic Units), 29 and 34 unique sequences were detected in the Methylococcaceae and Methylocystaceae, respectively, and 24 potential methanotrophs in the Beijerinckiaceae were also identified. Methylacidiphilum-like methanotrophs were not detected. Proteobacterial methanotrophic bacteria constitute <2% of microbiota in these environments, with the Methylocystaceae one to two orders of magnitude more abundant than the Methylococcaceae in all environments sampled. The Methylococcaceae are also less diverse in forest soil compared to the other two habitats. Nonmetric multidimensional scaling analyses indicated that the majority of methanotrophs from the Methylococcaceae and Methylocystaceae tend to occur in one habitat only (peat or Sphagnum moss) or co-occurred in both Sphagnum moss and peat. This study provides insights into the structure of methanotrophic communities in relationship to habitat type, and suggests that peat and Sphagnum moss can influence methanotroph community structure and biogeography. PMID:27682082

  4. A broad-scale comparison of aerobic activity levels in vertebrates: endotherms versus ectotherms.

    PubMed

    Gillooly, James F; Gomez, Juan Pablo; Mavrodiev, Evgeny V

    2017-02-22

    Differences in the limits and range of aerobic activity levels between endotherms and ectotherms remain poorly understood, though such differences help explain basic differences in species' lifestyles (e.g. movement patterns, feeding modes, and interaction rates). We compare the limits and range of aerobic activity in endotherms (birds and mammals) and ectotherms (fishes, reptiles, and amphibians) by evaluating the body mass-dependence of VO2 max, aerobic scope, and heart mass in a phylogenetic context based on a newly constructed vertebrate supertree. Contrary to previous work, results show no significant differences in the body mass scaling of minimum and maximum oxygen consumption rates with body mass within endotherms or ectotherms. For a given body mass, resting rates and maximum rates were 24-fold and 30-fold lower, respectively, in ectotherms than endotherms. Factorial aerobic scope ranged from five to eight in both groups, with scope in endotherms showing a modest body mass-dependence. Finally, maximum consumption rates and aerobic scope were positively correlated with residual heart mass. Together, these results quantify similarities and differences in the potential for aerobic activity among ectotherms and endotherms from diverse environments. They provide insights into the models and mechanisms that may underlie the body mass-dependence of oxygen consumption.

  5. Characterization of Two New Facultative Methanotrophs

    PubMed Central

    Lynch, Martha J.; Wopat, Ann E.; O'Connor, Mary L.

    1980-01-01

    Two new facultative methane-oxidizing bacteria have been isolated from lake water enrichments. The organisms have been characterized in terms of colony types, growth characteristics, the guanine plus cytosine content of their deoxyribonucleic acid, thin sections, oxidation rates, and carbon assimilation pathways. Methane-grown cells of both organisms contained intracytoplasmic membranes similar to those described as type II in other methanotrophic bacteria. Neither organism had such membranes when grown heterotrophically. Both organisms assimilated methane by way of the isocitrate lyase-negative serine pathway for formaldehyde incorporation. The enzymes of this pathway were high in specific activity in cells grown on methane and were at low levels in cells grown either on heterotrophic substrates or on heterotrophic substrates plus methane. It is proposed that both organisms be classified in the genus Methylobacterium as two new species, Methylobacterium ethanolicum and Methylobacterium hypolimneticum. Images PMID:16345617

  6. Reductive dechlorination of trichloroethylene and tetrachloroethylene under aerobic conditions in a sediment column

    SciTech Connect

    Enzien, M.V.; Picardal, F.; Hazen, T.

    1994-06-01

    This study investigated the bioremediation of chlorinated solvents in a sediment column. Biodegradation potentials of trichloroethylene and tetrachloroethylene during aerobic methanotrophic biostimulation were studied at the Savannah River Site. 30 refs., 3 figs., 3 tabs.

  7. Vertebrate blood cell volume increases with temperature: implications for aerobic activity

    PubMed Central

    Zenil-Ferguson, Rosana

    2014-01-01

    Aerobic activity levels increase with body temperature across vertebrates. Differences in these levels, from highly active to sedentary, are reflected in their ecology and behavior. Yet, the changes in the cardiovascular system that allow for greater oxygen supply at higher temperatures, and thus greater aerobic activity, remain unclear. Here we show that the total volume of red blood cells in the body increases exponentially with temperature across vertebrates, after controlling for effects of body size and taxonomy. These changes are accompanied by increases in relative heart mass, an indicator of aerobic activity. The results point to one way vertebrates may increase oxygen supply to meet the demands of greater activity at higher temperatures. PMID:24765580

  8. Associations of Methanotrophs With the Roots and Rhizomes of Aquatic Vegetation

    NASA Technical Reports Server (NTRS)

    King, Gary M.

    1994-01-01

    Results of an in vitro assay revealed that root-associated methane consumption was a common attribute or diverse emergent wetland macrophytes from a variety of habitats. Maximum potential uptake rates (V(sub maxp)) varied between about 1 and 10 micro mol g/ (dry weight) h, with no obvious correlation between rate and gross morphological characteristics of the plants. The V(sub maxp) corresponded to about 2 x 10(exp 18) to 2 x 10(exp 9) methanotrophs g/ (dry weight), assuming that root-associated methanotrophs have cell-specific activities comparable to those of known isolates. V(sub maxp) varied seasonally for an aquatic grass, Calamogrostis canadensis, and for the cattail, Typha latifolia, with highest rates in late summer. V(sub maxp) was well correlated with ambient temperature for C. canadensis but weakly correlated for T. Wifolia. The seasonal changes in V(sub maxp), as well as inferences from apparent half-saturation constants for methane uptake (K(sub app); generally 3 to 6 micro M), indicated that oxygen availability might be more important than methane as a rate determinant. In addition, roots incubated under anoxic conditions showed little or no postanoxia aerobic methane consumption, indicating that root-associated metbanotrophic populations might not tolerate variable oxygen availability. Hybridization of oligodeoxynucleotide probes specific for group 1 or group 2 methylotrophs also varied seasonally. The group 2-specific probe consistently hybridized to a greater extent than the group 1 probe, and the relative amount of group 2 probe hybridization to C. canadensis root extracts was positively correlated with V(sub maxp).

  9. Does increased physical activity in school affect children's executive function and aerobic fitness?

    PubMed

    Kvalø, S E; Bru, E; Brønnick, K; Dyrstad, S M

    2017-02-16

    This study seeks to explore whether increased PA in school affects children's executive function and aerobic fitness. The "Active school" study was a 10-month randomized controlled trial. The sample included 449 children (10-11 years old) in five intervention and four control schools. The weekly interventions were 2×45 minutes physically active academic lessons, 5×10 minutes physically active breaks, and 5×10 minutes physically active homework. Aerobic fitness was measured using a 10-minute interval running test. Executive function was tested using four cognitive tests (Stroop, verbal fluency, digit span, and Trail Making). A composite score for executive function was computed and used in analyses. Mixed ANCOVA repeated measures were performed to analyze changes in scores for aerobic fitness and executive function. Analysis showed a tendency for a time×group interaction on executive function, but the results were non-significant F(1, 344)=3.64, P=.057. There was no significant time×group interaction for aerobic fitness. Results indicate that increased physical activity in school might improve children's executive function, even without improvement in aerobic fitness, but a longer intervention period may be required to find significant effects.

  10. Field measures show methanotroph sensitivity to soil moisture follows precipitation regime of the grassland sites across the US Great Plains

    NASA Astrophysics Data System (ADS)

    Koyama, A.; Webb, C. T.; Johnson, N. G.; Brewer, P. E.; von Fischer, J. C.

    2015-12-01

    Methane uptake rates are known to have temporal variation in response to changing soil moisture levels. However, the relative importance of soil diffusivity vs. methanotroph physiology has not been disentangled to date. Testing methanotroph physiology in the laboratory can lead to misleading results due to changes in the fine-scale habitat where methanotrophs reside. To assay the soil moisture sensitivity of methanotrophs under field conditions, we studied 22 field plots scattered across eight Great Plains grassland sites that differed in precipitation regime and soil moisture, making ca. bi-weekly measures during the growing seasons over three years. Quantification of methanotroph activity was achieved from chamber-based measures of methane uptake coincident with SF6-derived soil diffusivity, and interpretation in a reaction-diffusion model. At each plot, we also measured soil water content (SWC), soil temperature and inorganic nitrogen (N) contents. We also assessed methanotroph community composition via 454 sequencing of the pmoA gene. Statistical analyses showed that methanotroph activity had a parabolic response with SWC (concave down), and significant differences in the shape of this response among sites. Moreover, we found that the SWC at peak methanotroph activity was strongly correlated with mean annual precipitation (MAP) of the site. The sequence data revealed distinct composition patterns, with structure that was associated with variation in MAP and soil texture. These results suggest that local precipitation regime shapes methanotroph community composition, which in turn lead to unique sensitivity of methane uptake rates with soil moisture. Our findings suggest that methanotroph activity may be more accurately modeled when the biological and environmental responses are explicitly described.

  11. A metagenomic study of methanotrophic microorganisms in Coal Oil Point seep sediments

    PubMed Central

    2011-01-01

    Background Methane oxidizing prokaryotes in marine sediments are believed to function as a methane filter reducing the oceanic contribution to the global methane emission. In the anoxic parts of the sediments, oxidation of methane is accomplished by anaerobic methanotrophic archaea (ANME) living in syntrophy with sulphate reducing bacteria. This anaerobic oxidation of methane is assumed to be a coupling of reversed methanogenesis and dissimilatory sulphate reduction. Where oxygen is available aerobic methanotrophs take part in methane oxidation. In this study, we used metagenomics to characterize the taxonomic and metabolic potential for methane oxidation at the Tonya seep in the Coal Oil Point area, California. Two metagenomes from different sediment depth horizons (0-4 cm and 10-15 cm below sea floor) were sequenced by 454 technology. The metagenomes were analysed to characterize the distribution of aerobic and anaerobic methanotrophic taxa at the two sediment depths. To gain insight into the metabolic potential the metagenomes were searched for marker genes associated with methane oxidation. Results Blast searches followed by taxonomic binning in MEGAN revealed aerobic methanotrophs of the genus Methylococcus to be overrepresented in the 0-4 cm metagenome compared to the 10-15 cm metagenome. In the 10-15 cm metagenome, ANME of the ANME-1 clade, were identified as the most abundant methanotrophic taxon with 8.6% of the reads. Searches for particulate methane monooxygenase (pmoA) and methyl-coenzyme M reductase (mcrA), marker genes for aerobic and anaerobic oxidation of methane respectively, identified pmoA in the 0-4 cm metagenome as Methylococcaceae related. The mcrA reads from the 10-15 cm horizon were all classified as originating from the ANME-1 clade. Conclusions Most of the taxa detected were present in both metagenomes and differences in community structure and corresponding metabolic potential between the two samples were mainly due to abundance

  12. Comparative studies of aerobic and anaerobic biodegradation of methylparaben and propylparaben in activated sludge.

    PubMed

    Wu, Yang; Sun, Qian; Wang, Yu-Wen; Deng, Cheng-Xun; Yu, Chang-Ping

    2017-04-01

    The biodegradability of two typical parabens (methylparaben and propylparaben) in activated sludge, at initial concentrations of 1mgL(-1) or 10mgL(-1), was investigated under aerobic and anaerobic conditions. The results showed that microorganisms played a key role in degradation of parabens in WWTPs, especially in aerobic systems. The half-lives of methylparaben and propylparaben under aerobic conditions have been estimated to range between 15.8 and 19.8min, and benzoic acid was found to be one of the major biodegradation products. The calculated biodegradation efficiency of methylparaben and propylparaben in activated sludge under aerobic conditions was significantly higher than that observed under anaerobic (nitrate, sulfate, and Fe (III) reducing) conditions, as methylparaben and propylparaben exhibited comparatively higher persistence in anaerobic systems, with half-lives ≥43.3h and ≥8.6h, respectively. Overall, the results of this study imply that the majority of these parabens can be eliminated by aerobic biodegradation during conventional wastewater treatment processes, whereas minor removal is possible in anaerobic systems if an insufficient hydraulic retention time was maintained.

  13. Change in energy expenditure and physical activity in response to aerobic and resistance exercise programs.

    PubMed

    Drenowatz, Clemens; Grieve, George L; DeMello, Madison M

    2015-01-01

    Exercise is considered an important component of a healthy lifestyle but there remains controversy on effects of exercise on non-exercise physical activity (PA). The present study examined the prospective association of aerobic and resistance exercise with total daily energy expenditure and PA in previously sedentary, young men. Nine men (27.0 ± 3.3 years) completed two 16-week exercise programs (3 exercise sessions per week) of aerobic and resistance exercise separated by a minimum of 6 weeks in random order. Energy expenditure and PA were measured with the SenseWear Mini Armband prior to each intervention as well as during week 1, week 8 and week 16 of the aerobic and resistance exercise program. Body composition was measured via dual x-ray absorptiometry. Body composition did not change in response to either exercise intervention. Total daily energy expenditure on exercise days increased by 443 ± 126 kcal/d and 239 ± 152 kcal/d for aerobic and resistance exercise, respectively (p < 0.01). Non-exercise moderate-to-vigorous PA, however, decreased on aerobic exercise days (-148 ± 161 kcal/d; p = 0.03). There was no change in total daily energy expenditure and PA on non-exercise days with aerobic exercise while resistance exercise was associated with an increase in moderate-to-vigorous PA during non-exercise days (216 ± 178 kcal/d, p = 0.01). Results of the present study suggest a compensatory reduction in PA in response to aerobic exercise. Resistance exercise, on the other hand, appears to facilitate non-exercise PA, particularly on non-exercise days, which may lead to more sustainable adaptations in response to an exercise program.

  14. III. The importance of physical activity and aerobic fitness for cognitive control and memory in children.

    PubMed

    Chaddock-Heyman, Laura; Hillman, Charles H; Cohen, Neal J; Kramer, Arthur F

    2014-12-01

    In this chapter, we review literature that examines the association among physical activity, aerobic fitness, cognition, and the brain in elementary school children (ages 7-10 years). Specifically, physical activity and higher levels of aerobic fitness in children have been found to benefit brain structure, brain function, cognition, and school achievement. For example, higher fit children have larger brain volumes in the basal ganglia and hippocampus, which relate to superior performance on tasks of cognitive control and memory, respectively, when compared to their lower fit peers. Higher fit children also show superior brain function during tasks of cognitive control, better scores on tests of academic achievement, and higher performance on a real-world street crossing task, compared to lower fit and less active children. The cross-sectional findings are strengthened by a few randomized, controlled trials, which demonstrate that children randomly assigned to a physical activity intervention group show greater brain and cognitive benefits compared to a control group. Because these findings suggest that the developing brain is plastic and sensitive to lifestyle factors, we also discuss typical structural and functional brain maturation in children to provide context in which to interpret the effects of physical activity and aerobic fitness on the developing brain. This research is important because children are becoming increasingly sedentary, physically inactive, and unfit. An important goal of this review is to emphasize the importance of physical activity and aerobic fitness for the cognitive and brain health of today's youth.

  15. Relationships Among Goal Contents, Exercise Motivations, Physical Activity, and Aerobic Fitness in University Physical Education Courses.

    PubMed

    Sibley, Benjamin A; Bergman, Shawn M

    2016-04-01

    The current research examined the relationships among exercise goal contents, behavioral regulation, physical activity, and aerobic fitness within the context of eight-week university physical education courses. Participants were undergraduate students (M age = 20.2 year, SD = 2.3) enrolled in activity courses (N = 461) during the 2010 Fall semester. At pretest, participants completed a demographic survey, Behavioral Regulation in Exercise Questionnaire and the Goal Contents in Exercise Questionnaire. At eight-week posttest, participants completed the Physical Activity Questionnaire for Adults and the PACER aerobic fitness test. Relative intrinsic goal content was found to predict physical activity indirectly and aerobic fitness via behavioral regulation. Specific goal contents related to health management and skill development were found to predict physical activity and aerobic fitness via a fully mediated path through identified and intrinsic regulation. Results supported the efficacy of goal contents and self-determination theory in describing physical activity behavior and fitness. Examining specific types of goal contents and behavioral regulations revealed relationships that were masked by the utilization of omnibus scoring protocols.

  16. Aerobic and anaerobic bioprocessing of activated sludge: floc disintegration by enzymes.

    PubMed

    Ayol, Azize; Filibeli, Ayse; Sir, Diclehan; Kuzyaka, Ersan

    2008-11-01

    Hydrolytic enzymes such as glucosidases, lipases, and proteases have an imperative function at the hydrolysis stage of complex organic structures in the degradation of biodegradable particulate organic matter. As a key factor, extracellular polymeric substances (EPS) control the extracellular hydrolytic enzymes in this degradation mechanism. A flocculated matrix of EPS bridging with bacteria holds back the dewaterability properties of the bioprocessed sludges. Disruption of the flocculated matrix leads to improved solubilization of sludge solids by attacking the hydrolytic enzymes to polymeric substances forming enzyme-substrate complexes. To determine the floc disintegration mechanisms by enzymes during aerobic and anaerobic bioprocessing of sludges, experimental data obtained from three aerobic digesters and three anaerobic digesters were evaluated. As part of a broader project examining the overall fate and effects of hydrolytic enzymes in biological sludge stabilization, this paper compares the performances of aerobic and anaerobic reactors used in this study and reports significant improvements in enzymatic treatment of activated sludge.

  17. [Analysis of hydrolytic enzyme activities on sludge aerobic/anoxic digestion after ultrasonic pretreatment].

    PubMed

    Ye, Yun-di; Sun, Shui-yu; Zheng, Li; Liu, Bao-jian; Xu, Yan-bin; Zhan, Xing-xing; Liu, Jing-yong

    2012-08-01

    In order to evaluate the function of sludge aerobic/anoxic digestibility by ultrasonic pretreatment. The SS, VSS and hydrolytic enzyme activities (amylase, glucosidase, protease, phosphatase) were measured before and after ultrasonic pretreatment (28 kHz, 0.15 kW x L(-1), 10 min). The results showed that the performances of aerobic/anoxic were greatly improved after ultrasonic pretreatment, the removal efficiency of VSS went to 44.3%, 7.8% better than of traditional aerobic/anoxic digestion. The variational trend of sludge hydrolytic enzyme activities increased firstly and then fell off during 13d digestion, the maximum of amylase activity and glucosidase activity in ultrasonic sludge, appeared in the 5 d, amylase activity was 0.104 micromol x g(-1) and glucosidase activity was 0.637 (micromol x g(-1). The maximum of intracellular protease activity and extracellular proteases activity in ultrasonic sludge, appeared in the 7 d, intracellular protease activity was 23.68 micromol x g(-1), higher than extracellular proteases activity, and it was playing a leading role in sludge digestion. The acid phosphatase activity of ultrasonic sludge was higher than the control sludge, and the alkaline phosphatase was sensitive to environment. So the alkaline phosphatase activity reduced when the internal properties of sludge was changed.

  18. Effects of an Aerobic Activity Program on the Cholesterol Levels of Adolescents.

    ERIC Educational Resources Information Center

    Looney, Marilyn A.; Rimmer, James H.

    1997-01-01

    Reports a study that examined the effects of a 15-week aerobic activity program on high school students' cholesterol levels. Analysis of control and participating students indicated that there were significant reductions in total cholesterol in the training group. There were no significant differences between groups in high density lipoprotein…

  19. The relation of childhood physical activity and aerobic fitness to brain function and cognition: a review.

    PubMed

    Khan, Naiman A; Hillman, Charles H

    2014-05-01

    Physical inactivity has been shown to increase the risk for several chronic diseases across the lifespan. However, the impact of physical activity and aerobic fitness on childhood cognitive and brain health has only recently gained attention. The purposes of this article are to: 1) highlight the recent emphasis for increasing physical activity and aerobic fitness in children's lives for cognitive and brain health; 2) present aspects of brain development and cognitive function that are susceptible to physical activity intervention; 3) review neuroimaging studies examining the cross-sectional and experimental relationships between aerobic fitness and executive control function; and 4) make recommendations for future research. Given that the human brain is not fully developed until the third decade of life, preadolescence is characterized by changes in brain structure and function underlying aspects of cognition including executive control and relational memory. Achieving adequate physical activity and maintaining aerobic fitness in childhood may be a critical guideline to follow for physical as well as cognitive and brain health.

  20. Studies on bacterial activities in aerobic and anaerobic waste water purification.

    PubMed

    Adamse, A D; Deinema, M H; Zehnder, A J

    1984-01-01

    Some aspects of the bacteriology of aerobic and anaerobic waste water purification are discussed in view of current opinions and recent developments in the technology of waste water treatment. Various contributions of scientific workers attached to the Department of Microbiology of the Agricultural University, Wageningen, during the past 65 years are summarized. Besides, present investigations are described and research activities in future indicated.

  1. Self-efficacy, physical activity, and aerobic fitness in middle school children: examination of a pedometer intervention program.

    PubMed

    Manley, Dana; Cowan, Patricia; Graff, Carolyn; Perlow, Michael; Rice, Pamela; Richey, Phyllis; Sanchez, Zoila

    2014-01-01

    Physical activity in children has been associated with a number of health benefits. Unfortunately, physical inactivity continues to increase. The purpose of this study was to examine the relationships among self-efficacy levels, physical activity, aerobic fitness, and body composition (relative body mass index [RBMI]) and to determine whether a school-based pedometer intervention program would improve those variables. The sample consisted of 116 rural 11- to 13-year-old students. Weakly positive correlations between self-efficacy, physical activity, and aerobic fitness and weakly correlated inverse relationships between self-efficacy, physical activity, aerobic fitness and RBMI were found. There was no statistical significance between the intervention and control group when analyzing outcome variables. These findings suggest that those with optimal RBMI levels have higher self-efficacy, physical activity and aerobic fitness levels. Although not statistically significant, the intervention group had greater improvements in mean self-efficacy scores, aerobic fitness levels, and RBMI.

  2. Recovery of methanotrophs from disturbance: population dynamics, evenness and functioning.

    PubMed

    Ho, Adrian; Lüke, Claudia; Frenzel, Peter

    2011-04-01

    Biodiversity is claimed to be essential for ecosystem functioning, but is threatened by anthropogenic disturbances. Prokaryotes have been assumed to be functionally redundant and virtually inextinguishable. However, recent work indicates that microbes may well be sensitive to environmental disturbance. Focusing on methane-oxidizing bacteria as model organisms, we simulated disturbance-induced mortality by mixing native with sterilized paddy soil in two ratios, 1:4 and 1:40, representing moderate and severe die-offs. Disturbed microcosms were compared with an untreated control. Recovery of activity and populations was followed over 4 months by methane uptake measurements, pmoA-qPCR, pmoA-based terminal restriction fragment length polymorphism and a pmoA-based diagnostic microarray. Diversity and evenness of methanotrophs decreased in disturbed microcosms, but functioning was not compromised. We consistently observed distinctive temporal shifts between type I and type II methanotrophs, and a rapid population growth leading to even higher cell numbers comparing disturbed microcosms with the control. Overcompensating mortality suggested that population size in the control was limited by competition with other bacteria. Overall, methanotrophs showed a remarkable ability to compensate for die-offs.

  3. Physical disturbance to ecological niches created by soil structure alters community composition of methanotrophs.

    PubMed

    Kumaresan, Deepak; Stralis-Pavese, Nancy; Abell, Guy C J; Bodrossy, Levente; Murrell, J Colin

    2011-10-01

    Aggregates of different sizes and stability in soil create a composite of ecological niches differing in terms of physico-chemical and structural characteristics. The aim of this study was to identify, using DNA-SIP and mRNA-based microarray analysis, whether shifts in activity and community composition of methanotrophs occur when ecological niches created by soil structure are physically perturbed. Landfill cover soil was subject to three treatments termed: 'control' (minimal structural disruption), 'sieved' (sieved soil using 2 mm mesh) and 'ground' (grinding using mortar and pestle). 'Sieved' and 'ground' soil treatments exhibited higher methane oxidation potentials compared with the 'control' soil treatment. Analysis of the active community composition revealed an effect of physical disruption on active methanotrophs. Type I methanotrophs were the most active methanotrophs in 'sieved' and 'ground' soil treatments, whereas both Type I and Type II methanotrophs were active in the 'control' soil treatment. The result emphasize that changes to a particular ecological niche may not result in an immediate change to the active bacterial composition and change in composition will depend on the ability of the bacterial communities to respond to the perturbation.

  4. Teaching Aerobic Fitness Concepts.

    ERIC Educational Resources Information Center

    Sander, Allan N.; Ratliffe, Tom

    2002-01-01

    Discusses how to teach aerobic fitness concepts to elementary students. Some of the K-2 activities include location, size, and purpose of the heart and lungs; the exercise pulse; respiration rate; and activities to measure aerobic endurance. Some of the 3-6 activities include: definition of aerobic endurance; heart disease risk factors;…

  5. Aerobic methanotrophy within the pelagic redox-zone of the Gotland Deep (central Baltic Sea)

    NASA Astrophysics Data System (ADS)

    Schmale, O.; Blumenberg, M.; Kießlich, K.; Jakobs, G.; Berndmeyer, C.; Labrenz, M.; Thiel, V.; Rehder, G.

    2012-12-01

    Water column samples taken in summer 2008 from the stratified Gotland Deep (central Baltic Sea) showed a strong gradient in dissolved methane concentrations from high values in the saline deep water (max. 504 nM) to low concentrations in the less dense, brackish surface water (about 4 nM). The steep methane-gradient (between 115 and 135 m water depth) within the redox-zone, which separates the anoxic deep part from the oxygenated surface water (oxygen concentration 0-0.8 mL L-1), implies a methane consumption rate of 0.28 nM d-1. The process of microbial methane oxidation within this zone was evident by a shift of the stable carbon isotope ratio of methane between the bottom water (δ13C CH4 = -82.4‰ and the redox-zone (δ13C CH4 = -38.7‰. Water column samples between 80 and 119 m were studied to identify the microorganisms responsible for the methane turnover in that depth interval. Notably, methane monooxygenase gene expression analyses for water depths covering the whole redox-zone demonstrated that accordant methanotrophic activity was probably due to only one phylotype of the aerobic type I methanotrophic bacteria. An imprint of these organisms on the particular organic matter was revealed by distinctive lipid biomarkers showing bacteriohopanepolyols and lipid fatty acids characteristic for aerobic type I methanotrophs (e.g., 35-aminobacteriohopane-30,31,32,33,34-pentol), corroborating their role in aerobic methane oxidation in the redox-zone of the central Baltic Sea.

  6. Removal of micropollutants from aerobically treated grey water via ozone and activated carbon.

    PubMed

    Hernández-Leal, L; Temmink, H; Zeeman, G; Buisman, C J N

    2011-04-01

    Ozonation and adsorption onto activated carbon were tested for the removal micropollutants of personal care products from aerobically treated grey water. MilliQ water spiked with micropollutants (100-1600 μgL(-1)) was ozonated at a dosing rate of 1.22. In 45 min, this effectively removed (>99%): Four parabens, bisphenol-A, hexylcinnamic aldehyde, 4-methylbenzylidene-camphor (4MBC), benzophenone-3 (BP3), triclosan, galaxolide and ethylhexyl methoxycinnamate. After 60 min, the removal efficiency of benzalkonium chloride was 98%, tonalide and nonylphenol 95%, octocrylene 92% and 2-phenyl-5-benzimidazolesulfonic acid (PBSA) 84%. Ozonation of aerobically treated grey water at an applied ozone dose of 15 mgL(-1), reduced the concentrations of octocrylene, nonylphenol, triclosan, galaxolide, tonalide and 4-methylbenzylidene-camphor to below limits of quantification, with removal efficiencies of at least 79%. Complete adsorption of all studied micropollutants onto powdered activated carbon (PAC) was observed in batch tests with milliQ water spiked with 100-1600 μgL(-1) at a PAC dose of 1.25 gL(-1) and a contact time of 5 min. Three granular activated carbon (GAC) column experiments were operated to treat aerobically treated grey water. The operation of a GAC column with aerobically treated grey water spiked with micropollutants in the range of 0.1-10 μgL(-1) at a flow of 0.5 bed volumes (BV)h(-1) showed micropollutant removal efficiencies higher than 72%. During the operation time of 1728 BV, no breakthrough of TOC or micropollutants was observed. Removal of micropollutants from aerobically treated grey water was tested in a GAC column at a flow of 2 BVh(-1). Bisphenol-A, triclosan, tonalide, BP3, galaxolide, nonylphenol and PBSA were effectively removed even after a stable TOC breakthrough of 65% had been reached. After spiking the aerobically treated effluent with micropollutants to concentrations of 10-100 μgL(-1), efficient removal to below limits of quantification

  7. 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

  8. Bacteriohopanepolyol signatures as markers for methanotrophic bacteria in peat moss

    NASA Astrophysics Data System (ADS)

    van Winden, Julia F.; Talbot, Helen M.; Kip, Nardy; Reichart, Gert-Jan; Pol, Arjan; McNamara, Niall P.; Jetten, Mike S. M.; Op den Camp, Huub J. M.; Sinninghe Damsté, Jaap S.

    2012-01-01

    Bacteriohopanepolyols (BHPs) are bacterial biomarkers with a likely potential to identify present and past methanotrophic communities. To unravel the methanotrophic community in peat bogs, we report the BHP signatures of type I and type II methanotrophs isolated from Sphagnum mosses and of an extreme acidophilic verrucomicrobial methanotroph. A type I Methylovulum-like strain (M200) contains a remarkable combination of BHPs, including a complete suite of mono-unsaturated aminobacteriohopanepentol, -tetrol and -triol. The Methylomonas-like strain (M5) mainly produces aminobacteriohopanepentol, characteristic for type I methanotrophs, and the Methylosinus-like strain (29) contains both aminobacteriohopanetetrol and aminobacteriohopanetriol, typical for a type II methanotroph. The type II methanotroph Methylocella palustris and the verrucomicrobial Methylacidiphilum fumariolicum strain SolV primarily produce aminotriol, which is also produced by many other bacteria. In Sphagnum mosses and underlying peat from a peat bog from Moorhouse, UK, the only detectable BHPs indicative of methanotrophs are aminobacteriohopanepentol (aminopentol) and aminobacteriohopanetetrol (aminotetrol), although both are relatively low in abundance compared to other BHPs. Aminopentol serves as a marker for type I methanotrophs, while aminotetrol may reflect the presence of both type I and type II methanotrophs. The similar quantities of aminotetrol and aminopentol indicate that the methanotrophic community in Sphagnum peat probably consist of a combination of both type I and type II methanotrophs, which is in line with previously published pmoA-based micro-array results.

  9. Aerobic Heterotrophic Bacterial Populations of Sewage and Activated Sludge

    PubMed Central

    Prakasam, T. B. S.; Dondero, N. C.

    1970-01-01

    Two procedures, the confidence interval method and Mountford's index, were tested in analyses of the microbial populations of 11 laboratory activated sludges acclimated to aromatic compounds. The two methods gave somewhat different results but indicated that the populations were quite dissimilar. The activity of seven of the sludges correlated well with the population structure. Some considerations in analysis of microbial population structure are discussed. PMID:5418947

  10. Succession of methanotrophs in oxygen-methane counter-gradients of flooded rice paddies.

    PubMed

    Krause, Sascha; Lüke, Claudia; Frenzel, Peter

    2010-12-01

    Little is known about population dynamics and contribution of specific taxa to methane oxidation in flooded rice paddies. In this article we investigate the succession of methanotrophs in oxygen-methane counter-gradients. We used a gradient microcosm system that simulates oxic-anoxic interfaces of a water-saturated paddy soils, and measured pmoA-based (gene encoding particulate methane monooxygenase) terminal restriction fragment length polymorphism (T-RFLP) profiles at both the transcription (mRNA) and the population (DNA) levels. The DNA T-RFLP profiles indicated that the methanotrophic community present clearly differed from the active methanotrophic community. We observed a succession of the methanotrophic community over time without any direct effect of pore water chemistry on the community structure. Both the total population and the active subpopulation changed with time, whereas methane oxidation rates remained nearly constant. Hence, we suggest that a diverse microbial seed bank of methanotrophs is important in maintaining the function in a dynamic ecosystem.

  11. Methane source strength and energy flow shape methanotrophic communities in oxygen-methane counter-gradients.

    PubMed

    Krause, Sascha; Lüke, Claudia; Frenzel, Peter

    2012-04-01

    The role of microbial diversity for ecosystem functioning has become an important subject in microbial ecology. Recent work indicates that microbial communities and microbial processes can be very sensitive to anthropogenic disturbances. However, to what extent microbial communities may change upon, resist to, or overcome disturbances might differ depending on substrate availability. We used soil from an Italian rice field in gradient microcosms, and analysed the response of methanotrophic communities to an NH4 (+) pulse as a potential disturbance under two different CH4 source strengths. We found a significant influence of source strength, i.e. the energy flow through the methanotrophic community, while NH4 (+) had no effect. Our data suggest that historical contingencies, i.e. nitrogen fertilization, led to an ammonium-tolerant MOB community. Methanotrophs were able to oxidize virtually all CH4 diffusing into the oxic-anoxic boundary layer regardless of NH4 (+) addition. Total and active methanotrophic communities were assessed by a pmoA-specific microarray. From the reservoir of dormant methanotrophs, different species became active with Methylobacter and an environmental cluster affiliated with paddy soils being indicative for high CH4 source strength. Thus, a microbial seed bank is an important prerequisite to maintain functioning in a fluctuating environment.

  12. Changes in Cortical Activation Patterns in Language Areas following an Aerobic Exercise Intervention in Older Adults

    PubMed Central

    Crosson, Bruce; Mammino, Kevin; McGregor, Keith M.

    2017-01-01

    Previous work has shown that older adults who evidence increased right inferior frontal gyrus (IFG) activity during language tasks show decreased sematic verbal fluency performance. The current study sought to evaluate if an aerobic exercise intervention can alter patterns of brain activity during a semantic verbal fluency task assessed by functional magnetic resonance imaging (fMRI). Thirty-two community-dwelling, sedentary older adults were enrolled to a 12-week aerobic “Spin” exercise group or a 12-week nonaerobic exercise control condition (Balance). Thirty participants completed their assigned intervention (16 Spin; 14 Balance) with pre- and postintervention assessments of a semantic verbal fluency task during fMRI and estimated VO2max testing. There was a significant increase in the change scores for estimated VO2max of the Spin group when compared to the Balance group. Semantic verbal fluency output within the scanner was also improved in the Spin group as compared to controls at postassessment. Group fMRI comparisons of IFG activity showed lower activity in the right IFG following the intervention in the aerobic Spin group when compared to the Balance group. Regression analysis of imaging data with change in both estimated VO2max and semantic verbal fluency was negatively correlated with activity in right IFG. The current work is registered as clinical trial with NCT01787292 and NCT02787655. PMID:28367334

  13. Aerobic composting of waste activated sludge: Kinetic analysis for microbiological reaction and oxygen consumption

    SciTech Connect

    Yamada, Y.; Kawase, Y. . E-mail: bckawase@mail.eng.toyo.ac.jp

    2006-07-01

    In order to examine the optimal design and operating parameters, kinetics for microbiological reaction and oxygen consumption in composting of waste activated sludge were quantitatively examined. A series of experiments was conducted to discuss the optimal operating parameters for aerobic composting of waste activated sludge obtained from Kawagoe City Wastewater Treatment Plant (Saitama, Japan) using 4 and 20 L laboratory scale bioreactors. Aeration rate, compositions of compost mixture and height of compost pile were investigated as main design and operating parameters. The optimal aerobic composting of waste activated sludge was found at the aeration rate of 2.0 L/min/kg (initial composting mixture dry weight). A compost pile up to 0.5 m could be operated effectively. A simple model for composting of waste activated sludge in a composting reactor was developed by assuming that a solid phase of compost mixture is well mixed and the kinetics for microbiological reaction is represented by a Monod-type equation. The model predictions could fit the experimental data for decomposition of waste activated sludge with an average deviation of 2.14%. Oxygen consumption during composting was also examined using a simplified model in which the oxygen consumption was represented by a Monod-type equation and the axial distribution of oxygen concentration in the composting pile was described by a plug-flow model. The predictions could satisfactorily simulate the experiment results for the average maximum oxygen consumption rate during aerobic composting with an average deviation of 7.4%.

  14. Long-term aerobic exercise increases redox-active iron through nitric oxide in rat hippocampus.

    PubMed

    Chen, Qian; Xiao, De-Sheng

    2014-01-30

    Adult hippocampus is highly vulnerable to iron-induced oxidative stress. Aerobic exercise has been proposed to reduce oxidative stress but the findings in the hippocampus are conflicting. This study aimed to observe the changes of redox-active iron and concomitant regulation of cellular iron homeostasis in the hippocampus by aerobic exercise, and possible regulatory effect of nitric oxide (NO). A randomized controlled study was designed in the rats with swimming exercise treatment (for 3 months) and/or an unselective inhibitor of NO synthase (NOS) (L-NAME) treatment. The results from the bleomycin-detectable iron assay showed additional redox-active iron in the hippocampus by exercise treatment. The results from nonheme iron content assay, combined with the redox-active iron content, showed increased storage iron content by exercise treatment. NOx (nitrate plus nitrite) assay showed increased NOx content by exercise treatment. The results from the Western blot assay showed decreased ferroportin expression, no changes of TfR1 and DMT1 expressions, increased IRP1 and IRP2 expression, increased expressions of eNOS and nNOS rather than iNOS. In these effects of exercise treatment, the increased redox-active iron content, storage iron content, IRP1 and IRP2 expressions were completely reversed by L-NAME treatment, and decreased ferroportin expression was in part reversed by L-NAME. L-NAME treatment completely inhibited increased NOx and both eNOS and nNOS expression in the hippocampus. Our findings suggest that aerobic exercise could increase the redox-active iron in the hippocampus, indicating an increase in the capacity to generate hydroxyl radicals through the Fenton reactions, and aerobic exercise-induced iron accumulation in the hippocampus might mainly result from the role of the endogenous NO.

  15. Characteristics of dissolved organic matter formed in aerobic and anaerobic digestion of excess activated sludge.

    PubMed

    Du, Haixia; Li, Fusheng

    2017-02-01

    The characteristics of dissolved organic matter (DOM) formed in aerobic and anaerobic digestion of excess activated sludge (EAS) was investigated for three total solid (TS) concentrations (1.2, 2.3 and 5.2%) and three temperatures (5, 20 and 35 °C). The results on the overall concentration of DOM evaluated by TOC showed significantly higher values in anaerobic than aerobic digestion (2.8-6.9 times for TS 1.2-5.2% at 20 °C). Data analysis with a first-order sequential reaction model revealed that higher occurrence of DOM in anaerobic digestion was a result of comparatively faster hydrolysis (1.3-5.5 times for TS 1.2-5.2% at 20 °C; 1.4-49.3 times for temperatures 5-35 °C with TS 1.2%) and slower degradation (0.3-1.0 times for TS 1.2-5.2% at 20 °C; 0.5-8.3 times for temperatures 5-35 °C with TS 1.2%). In aerobic digestion, more humic substances were formed; while, in anaerobic digestion, proteins and aromatic amino acids were the major constituents. For both digestions, except for a few exceptions, proteins and humic substances increased as the TS concentration increased; and increasing the temperature led to a decrease in the content of proteins formed in both aerobic and anaerobic digestion, and an increase in the content of humic substances in the aerobic digestion. The UV-absorbing DOM constituents were highly heterogeneous, and were comparatively larger in anaerobic digestion; and did not change significantly with the TS concentrations and temperatures.

  16. The relationship between human skeletal muscle pyruvate dehydrogenase phosphatase activity and muscle aerobic capacity.

    PubMed

    Love, Lorenzo K; LeBlanc, Paul J; Inglis, J Greig; Bradley, Nicolette S; Choptiany, Jon; Heigenhauser, George J F; Peters, Sandra J

    2011-08-01

    Pyruvate dehydrogenase (PDH) is a mitochondrial enzyme responsible for regulating the conversion of pyruvate to acetyl-CoA for use in the tricarboxylic acid cycle. PDH is regulated through phosphorylation and inactivation by PDH kinase (PDK) and dephosphorylation and activation by PDH phosphatase (PDP). The effect of endurance training on PDK in humans has been investigated; however, to date no study has examined the effect of endurance training on PDP in humans. Therefore, the purpose of this study was to examine differences in PDP activity and PDP1 protein content in human skeletal muscle across a range of muscle aerobic capacities. This association is important as higher PDP activity and protein content will allow for increased activation of PDH, and carbohydrate oxidation. The main findings of this study were that 1) PDP activity (r(2) = 0.399, P = 0.001) and PDP1 protein expression (r(2) = 0.153, P = 0.039) were positively correlated with citrate synthase (CS) activity as a marker for muscle aerobic capacity; 2) E1α (r(2) = 0.310, P = 0.002) and PDK2 protein (r(2) = 0.229, P =0.012) are positively correlated with muscle CS activity; and 3) although it is the most abundant isoform, PDP1 protein content only explained ∼ 18% of the variance in PDP activity (r(2) = 0.184, P = 0.033). In addition, PDP1 in combination with E1α explained ∼ 38% of the variance in PDP activity (r(2) = 0.383, P = 0.005), suggesting that there may be alternative regulatory mechanisms of this enzyme other than protein content. These data suggest that with higher muscle aerobic capacity (CS activity) there is a greater capacity for carbohydrate oxidation (E1α), in concert with higher potential for PDH activation (PDP activity).

  17. Daily physical activity and blood lactate indices of aerobic fitness in children.

    PubMed Central

    Welsman, J R; Armstrong, N

    1992-01-01

    This study examined the relationship between daily physical activity and aerobic fitness in 11-16-year-olds. Habitual physical activity was assessed in 28 boys (mean(s.d.) age 13.6(1.3) years) and 45 girls (mean(s.d) age 13.7(1.3) years) from minute-by-minute heart rate monitoring during 3 school days. Aerobic fitness was assessed by determining the percentage peak VO2 at blood lactate reference values of 2.5 and 4.0 mmol l-1 during incremental treadmill running. The 4.0 mmol l-1 level occurred at a mean(s.d.) value of 89(7)% peak VO2 in both boys and girls and mean(s.d.) values at the 2.5 mmol l-1 level were 82(9)% peak VO2 in girls. Mean(s.d.) percentage time with heart rates at or above 140 beats min-1 was 6(3)% in boys and 5(3)% in girls. Corresponding values for percentage time at or above 160 beats min-1 were 3(2) for boys and 2(1) for girls. The number of 10- and 20-min periods of activity with the heart rate sustained above the 140 and 160 beats min-1 thresholds were also totalled over the 3 days. No significant relationships were identified between percentage peak VO2 at the 2.5 or 4.0 mmol l-1 blood lactate reference levels and either percentage time or number of 10- or 20-min periods above 140 or 160 beats min-1 (P > 0.05). These results support the hypothesis that daily physical activity levels in 11-16-year-old children do not stress aerobic metabolism sufficiently to influence aerobic fitness. PMID:1490213

  18. [Advances in degradation of chlorinated hydrocarbons by obligate and facultative methanotrophs].

    PubMed

    Xing, Zhilin; Zhang, Lijie; Zhao, Tiantao

    2014-04-01

    Bioremediation is one of the most effective ways to treat and dispose of chlorinated hydrocarbons, and methanotrophs are potentially useful to do so. Recent studies found that facultative methanotrophs can use compounds containing C-C bond as sources of carbon and energy, thus overcoming the limitation that obligate methanotrophsone uses only C1 compounds for this process. This is a unique metabolic approach that is becoming increasingly attractive in the field of contaminant biodegradation. Here, we summarized the bioremediation of chlorinated hydrocarbons by obligate and facultative methanotrophs. This process involves the degradation of various chlorinated hydrocarbons by diverse strains, including pure cultures and mixed cultures. We also compare the activity expression and catalytic properties of different types of methane monooxygenases in various substrates. We furthermore summarize the kinetic characteristics of the degradation of chlorinated hydrocarbons using the model strain Methylosinus trichosporium OB3b, and outline the degradation and potential of chlorinated hydrocarbons by facultative methanotrophs. Lastly, we discuss current problems and future research directions for degradation of chlorinated hydrocarbons by methanotrophs.

  19. Top-down control of methanotrophs regulates methane concentrations in a small humic lake

    NASA Astrophysics Data System (ADS)

    Saarenheimo, Jatta; Devlin, Shawn; Syväranta, Jari; Tiirola, Marja; Jones, Roger

    2014-05-01

    Many boreal lakes are known to be significant sources of methane (CH4), as methane production in anaerobic layers of boreal stratified lakes often exceeds oxidation of methane by methanotrophs, leading to methane fluxes to the atmosphere. In order to investigate whether trophic interactions control methanotrophy via regulation of bacterial community dynamics, we experimentally divided a small, humic, and fishless lake with high zooplankton abundance into two treatment basins. We then established either a) equal biomass of juvenile (12 cm) European perch (Perca fluviatilis) or b) adult fish and no fish in the two basins. We hypothesized that differences in predator presence and size would result in cascading trophic interactions, altering the abundance of zooplankton (Daphnia sp.) which are known to graze methanotrophic bacteria. Concurrently with zooplankton abundance and methane concentration measurements, methanotrophic bacterial abundance was assessed by quantitative PCR by targeting specific functional genes (pmoA). Fish presence, regardless of size, exerted high grazing pressure on zooplankton dramatically reducing their biomass. This shift in zooplankton density resulted in corresponding changes in methanotrophic bacterial abundance. We found a clear difference between epilimnetic methane concentrations for each treatment during the experiment, whereas the hypolimnetic methane concentrations showed no differences. The observed variation in epilimnetic methane concentrations was clearly linked to methanotrophic abundance/activity, which, in turn, was regulated by Daphnia biomass. This illustrates that cascading trophic interactions can be important regulators of methane concentration in stratified humic lakes and that previously unrelated ecological properties, fish abundance and atmospheric greenhouse gas concentrations, appear to be linked.

  20. Chromium Isotope Behaviour During Aerobic Microbial Reduction Activities

    NASA Astrophysics Data System (ADS)

    Zhang, Q.; Amor, K.; Porcelli, D.; Thompson, I.

    2014-12-01

    Microbial activity is a very important, and possibly even the dominant, reduction mechanism for many metals in natural water systems. Isotope fractionations during microbial metal reduction can reflect one major mechanism in metal cycling in the environment, and isotopic signatures can be used to identify and quantify reduction processes during biogeochemical cycling in the present environment as well as in the past. There are many Cr (VI)-reducing bacteria that have been discovered and isolated from the environment, and Cr isotopes were found to be fractionated during microbial reduction processes. In this study, Cr reduction experiments have been undertaken to determine the conditions under which Cr is reduced and the corresponding isotope signals that are generated. The experiments have been done with a facultative bacteria Pseudomonas fluorescens LB 300, and several parameters that have potential impact on reduction mechanisms have been investigated. Electron donors are important for bacteria growth and metabolism. One factor that can control the rate of Cr reduction is the nature of the electron donor. The results show that using citrate as an electron donor can stimulate bacteria reduction activity to a large extent; the reduction rate is much higher (15.10 mgˑL-1hour-1) compared with experiments using glucose (6.65 mgˑL-1ˑhour-1), acetate (4.88 mgˑL-1hour-1) or propionate (4.85 mgˑL-1hour-1) as electron donors. Groups with higher electron donor concentrations have higher reduction rates. Chromium is toxic, and when increasing Cr concentrations in the medium, the bacteria reduction rate is also higher, which reflects bacteria adapting to the toxic environment. In the natural environment, under different pH conditions, bacteria may metabolise in different ways. In our experiments with pH, bacteria performed better in reducing Cr (VI) when pH = 8, and there are no significant differences between groups with pH = 4 or pH = 6. To investigate this further, Cr

  1. Fly ash application in nutrient poor agriculture soils: impact on methanotrophs population dynamics and paddy yields.

    PubMed

    Singh, Jay Shankar; Pandey, Vimal Chandra

    2013-03-01

    There are reports that the application of fly ash, compost and press mud or a combination thereof, improves plant growth, soil microbial communities etc. Also, fly ash in combination with farmyard manure or other organic amendments improves soil physico-chemical characteristics, rice yield and microbial processes in paddy fields. However, the knowledge about the impact of fly ash inputs alone or in combination with other organic amendments on soil methanotrophs number in paddy soils is almost lacking. We hypothesized that fly ash application at lower doses in paddy agriculture soil could be a potential amendment to elevate the paddy yields and methanotrophs number. Here we demonstrate the impact of fly ash and press mud inputs on number of methanotrophs, antioxidants, antioxidative enzymatic activities and paddy yields at agriculture farm. The impact of amendments was significant for methanotrophs number, heavy metal concentration, antioxidant contents, antioxidant enzymatic activities and paddy yields. A negative correlation was existed between higher doses of fly ash-treatments and methanotrophs number (R(2)=0.833). The content of antioxidants and enzymatic activities in leaves of higher doses fly ash-treated rice plants increased in response to stresses due to heavy metal toxicity, which was negatively correlated with rice grain yield (R(2)=0.944) and paddy straw yield (R(2)=0.934). A positive correlation was noted between heavy metals concentrations and different antioxidant and enzymatic activities across different fly ash treated plots.The data of this study indicate that heavy metal toxicity of fly ash may cause oxidative stress in the paddy crop and the antioxidants and related enzymes could play a defensive role against phytotoxic damages. We concluded that fly ash at lower doses with press mud seems to offer the potential amendments to improving soil methanotrophs population and paddy crop yields for the nutrient poor agriculture soils.

  2. Acute effects of dynamic stretching, static stretching, and light aerobic activity on muscular performance in women.

    PubMed

    Curry, Brad S; Chengkalath, Devendra; Crouch, Gordon J; Romance, Michelle; Manns, Patricia J

    2009-09-01

    The purpose of this study was to compare three warm-up protocols--static stretching, dynamic stretching, and light aerobic activity--on selected measures of range of motion and power in untrained females and to investigate the sustained effects at 5 and 30 minutes after warm-up. A total of 24 healthy females (ages 23-29 years) attended one familiarization session and three test sessions on nonconsecutive days within 2 weeks. A within-subject design protocol with the testing investigators blinded to the subjects' warm-up was followed. Each session started with 5 minutes of light aerobic cycling followed by pretest baseline measures. Another 5 minutes of light aerobic cycling was completed and followed by one of the three randomly selected warm-up interventions (static stretching, dynamic stretching, or light aerobic activity). The following posttest outcome measures were collected 5 and 30 minutes following the intervention: modified Thomas test, countermovement jump, and isometric time to peak force knee extension measured by dynamometer. Analysis of the data revealed significant time effects on range of motion and countermovement jump changes. No significant differences (p > 0.05) were found between the warm-up conditions on any of the variables. The variation in responses to warm-up conditions emphasizes the unique nature of individual reactions to different warm-ups; however, there was a tendency for warm-ups with an active component to have beneficial effects. The data suggests dynamic stretching has greater applicability to enhance performance on power outcomes compared to static stretching.

  3. Aerobic Tennis.

    ERIC Educational Resources Information Center

    Stewart, Michael J.; Ahlschwede, Robert

    1989-01-01

    Increasing the aerobic nature of tennis drills in the physical education class may be necessary if tennis is to remain a part of the public school curriculum. This article gives two examples of drills that can be modified by teachers to increase activity level. (IAH)

  4. Aerobic activated sludge transformation of methotrexate: identification of biotransformation products.

    PubMed

    Kosjek, Tina; Negreira, Noelia; de Alda, Miren López; Barceló, Damià

    2015-01-01

    This study describes the biotransformation of cytostatic and immunosuppressive pharmaceutical methotrexate. Its susceptibility to microbiological breakdown was studied in a batch biotransformation system, in presence or absence of carbon source and at two activated sludge concentrations. The primary focus of the present study are methotrexate biotransformation products, which were tentatively identified by the ultra-high performance liquid chromatography-quadrupole--Orbitrap-MS. Data-dependent experiments, combining full-scan MS data with product ion spectra were acquired, in order to identify the molecular ions of methotrexate transformation products, to propose the molecular formulae and to elucidate their chemical structures. Among the identified transformation products 2,4-diamino-N10-methyl-pteroic acid is most abundant and persistent. Other biotransformation reactions involve demethylation, oxidative cleavage of amine, cleavage of C-N bond, aldehyde to carboxylate transformation and hydroxylation. Finally, a breakdown pathway is proposed, which shows that most of methotrexate breakdown products retain the diaminopteridine structural segment. In total we propose nine transformation products, among them eight are described as methotrexate transformation products for the first time.

  5. Internal recycle to improve denitrification in a step feed anoxic/aerobic activated sludge system.

    PubMed

    Boyle, C A; McKenzie, C J; Morgan, S

    2009-01-01

    During periods of low load (weekends and holidays) the Mangere wastewater treatment plant effluent has breached the summer consent conditions for total nitrogen. The purpose of this research was to determine if an internal recycle would improve nitrogen removal in the anoxic/aerobic activated sludge reactors sufficient to meet the summer resource consent standard. The recycle returned nitrate rich mixed liquor from the downstream aerobic zone back to the initial anoxic zone, thus potentially improving denitrification. A full scale trial showed that installation of the internal recycle on each RC would have satisfied the resource consent for total nitrogen in most cases over the three summer resource consent periods since the upgrade. However, further modifications of the internal recycle would be required to ensure that consent conditions were satisfied at all times and to improve the consistency of the results.

  6. Issues of Health, Appearance and Physical Activity in Aerobic Classes for Women

    ERIC Educational Resources Information Center

    D'Abundo, Michelle Lee

    2009-01-01

    The purpose of this research was to explore what appearance-focused messages were conveyed by aerobic instructors in aerobic classes for women. This qualitative research was influenced by the concept of wellness and how feminist pedagogy can be applied to promote individuals' well-being in aerobic classes. The practices of five aerobic instructors…

  7. 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

  8. Genes and enzymes of ectoine biosynthesis in halotolerant methanotrophs.

    PubMed

    Reshetnikov, Alexander S; Khmelenina, Valentina N; Mustakhimov, Ildar I; Trotsenko, Yuri A

    2011-01-01

    Ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidine carboxylic acid) is a widely distributed compatible solute accumulated by halophilic and halotolerant microorganisms to prevent osmotic stress in highly saline environments. Ectoine as a highly water keeping compound stabilizing biomolecules and whole cells can be used in scientific work, cosmetics, and medicine. Detailed understanding of the organization/regulation of the ectoine biosynthetic pathway in various producers is an active area of research. Here we review current knowledge on some genetic and enzymatic aspects of ectoine biosynthesis in halophilic and halotolerant methanotrophs. By using PCR methodology, the genes coding for the specific enzymes of ectoine biosynthesis, diaminobutyric acid (DABA) aminotransferase (EctB), DABA acetyltransferase (EctA), and ectoine synthase (EctC), were identified in several methanotrophic species. Organization of these genes in either ectABC or ectABC-ask operons, the latter additionally encoding aspartate kinase isozyme (Ask), correlated well with methanotroph halotolerance and intracellular ectoine level. A new gene, ectR1 encoding the MarR-like transcriptional regulatory protein EctR1, negatively controlling transcription of ectoine biosynthetic genes was found upstream of ectABC-ask operon in Methylomicrobium alcaliphilum 20Z. The ectR-like genes were also found in halotolerant methanol utilizers Methylophaga alcalica and Methylophaga thalassica as well as in several genomes of nonmethylotrophic species. The His(6)-tagged DABA acetyltransferases from Mm. alcaliphilum, M. alcalica, and M. thalassica were purified and the enzyme properties were found to correlate with the ecophysiologies of these bacteria. All these discoveries should be very helpful for better understanding the biosynthetic mechanism of this important natural compound, and for the targeted metabolic engineering of its producers.

  9. Starvation and recovery in the deep-sea methanotroph Methyloprofundus sedimenti.

    PubMed

    Tavormina, Patricia L; Kellermann, Matthias Y; Antony, Chakkiath Paul; Tocheva, Elitza I; Dalleska, Nathan F; Jensen, Ashley J; Valentine, David L; Hinrichs, Kai-Uwe; Jensen, Grant J; Dubilier, Nicole; Orphan, Victoria J

    2017-01-01

    In the deep ocean, the conversion of methane into derived carbon and energy drives the establishment of diverse faunal communities. Yet specific biological mechanisms underlying the introduction of methane-derived carbon into the food web remain poorly described, due to a lack of cultured representative deep-sea methanotrophic prokaryotes. Here, the response of the deep-sea aerobic methanotroph Methyloprofundus sedimenti to methane starvation and recovery was characterized. By combining lipid analysis, RNA analysis, and electron cryotomography, it was shown that M. sedimenti undergoes discrete cellular shifts in response to methane starvation, including changes in headgroup-specific fatty acid saturation levels, and reductions in cytoplasmic storage granules. Methane starvation is associated with a significant increase in the abundance of gene transcripts pertinent to methane oxidation. Methane reintroduction to starved cells stimulates a rapid, transient extracellular accumulation of methanol, revealing a way in which methane-derived carbon may be routed to community members. This study provides new understanding of methanotrophic responses to methane starvation and recovery, and lays the initial groundwork to develop Methyloprofundus as a model chemosynthesizing bacterium from the deep sea.

  10. Accelerometer-measured daily physical activity related to aerobic fitness in children and adolescents.

    PubMed

    Dencker, Magnus; Andersen, Lars B

    2011-06-01

    Maximum oxygen uptake (VO(2PEAK)) is generally considered to be the best single marker for aerobic fitness. While a positive relationship between daily physical activity and aerobic fitness has been established in adults, the relationship appears less clear in children and adolescents. The purpose of this paper is to summarise recently published data on the relationship between daily physical activity, as measured by accelerometers, and VO(2PEAK) in children and adolescents. A PubMed search was performed on 29 October 2010 to identify relevant articles. Studies were considered relevant if they included measurement of daily physical activity by accelerometry and related to a VO(2PEAK) either measured directly at a maximal exercise test or estimated from maximal power output. A total of nine studies were identified, with a total number of 6116 children and adolescents investigated. Most studies reported a low-to-moderate relationship (r = 0.10-0.45) between objectively measured daily physical activity and VO(2PEAK). No conclusive evidence exists that physical activity of higher intensities are more closely related to VO(2PEAK), than lower intensities.

  11. Widespread methanotrophic primary production in lowland chalk rivers.

    PubMed

    Shelley, Felicity; Grey, Jonathan; Trimmer, Mark

    2014-05-22

    Methane is oversaturated relative to the atmosphere in many rivers, yet its cycling and fate is poorly understood. While photosynthesis is the dominant source of autotrophic carbon to rivers, chemosynthesis and particularly methane oxidation could provide alternative sources of primary production where the riverbed is heavily shaded or at depth beneath the sediment surface. Here, we highlight geographically widespread methanotrophic carbon fixation within the gravel riverbeds of over 30 chalk rivers. In 15 of these, the potential for methane oxidation (methanotrophy) was also compared with photosynthesis. In addition, we performed detailed concurrent measurements of photosynthesis and methanotrophy in one large chalk river over a complete annual cycle, where we found methanotrophy to be active to at least 15 cm into the riverbed and to be strongly substrate limited. The seasonal trend in methanotrophic activity reflected that of the riverine methane concentrations, and thus the highest rates were measured in mid-summer. At the sediment surface, photosynthesis was limited by light for most of the year with heavy shading induced by dense beds of aquatic macrophytes. Across 15 rivers, in late summer, we conservatively calculated that net methanotrophy was equivalent to between 1% and 46% of benthic net photosynthetic production within the gravel riverbed, with a median value of 4%. Hence, riverbed chemosynthesis, coupled to the oxidation of methane, is widespread and significant in English chalk rivers.

  12. Preparation of activated carbon from sugarcane bagasse by microwave assisted activation for the remediation of semi-aerobic landfill leachate.

    PubMed

    Foo, K Y; Lee, L K; Hameed, B H

    2013-04-01

    This study evaluates the sugarcane bagasse derived activated carbon (SBAC) prepared by microwave heating for the adsorptive removal of ammonical nitrogen and orthophosphate from the semi-aerobic landfill leachate. The physical and chemical properties of SBAC were examined by pore structural analysis, scanning electron microscopy, Fourier transform infrared spectroscopy and elemental analysis. The effects of adsorbent dosage, contact time and solution pH on the adsorption performance were investigated in a batch mode study at 30°C. Equilibrium data were favorably described by the Langmuir isotherm model, with a maximum monolayer adsorption capacity for ammonical nitrogen and orthophosphate of 138.46 and 12.81 mg/g, respectively, while the adsorption kinetic was best fitted to the pseudo-second-order kinetic model. The results illustrated the potential of sugarcane bagasse derived activated carbon for the adsorptive treatment of semi-aerobic landfill leachate.

  13. Metabolic engineering in methanotrophic bacteria

    SciTech Connect

    Kalyuzhnaya, MG; Puri, AW; Lidstrom, ME

    2015-05-01

    Methane, as natural gas or biogas, is the least expensive source of carbon for (bio)chemical synthesis. Scalable biological upgrading of this simple alkane to chemicals and fuels can bring new sustainable solutions to a number of industries with large environmental footprints, such as natural gas/petroleum production, landfills, wastewater treatment, and livestock. Microbial biocatalysis with methane as a feedstock has been pursued off and on for almost a half century, with little enduring success. Today, biological engineering and systems biology provide new opportunities for metabolic system modulation and give new optimism to the concept of a methane-based bio-industry. Here we present an overview of the most recent advances pertaining to metabolic engineering of microbial methane utilization. Some ideas concerning metabolic improvements for production of acetyl-CoA and pyruvate, two main precursors for bioconversion, are presented. We also discuss main gaps in the current knowledge of aerobic methane utilization, which must be solved in order to release the full potential of methane-based biosystems. (C) 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  14. Relationships Among Two Repeated Activity Tests and Aerobic Fitness of Volleyball Players.

    PubMed

    Meckel, Yoav; May-Rom, Moran; Ekshtien, Aya; Eisenstein, Tamir; Nemet, Dan; Eliakim, Alon

    2015-08-01

    The purpose of the study was to determine performance indices of a repeated sprint test (RST) and to examine their relationships with performance indices of a repeated jump test (RJT) and with aerobic fitness among trained volleyball players. Sixteen male volleyball players performed RST (6 × 30 m sprints), RJT (6 sets of 6 consecutive jumps), and an aerobic power test (20-m Shuttle Run Test). Performance indices for the RST and the RJT were (a) the ideal 30-m run time (IS), the total run time (TS) of the 6 sprints, and the performance decrement (PD) during the test and (b) the ideal jump height (IJ), the total jump height (TJ) of all the jumps, and the PD during the test, respectively. No significant correlations were found between performance indices of the RST and RJT. Significant correlations were found between PD, IS, and TS in the RST protocol and predicted peak V[Combining Dot Above]O2 (r = -0.60, -0.75, -0.77, respectively). No significant correlations were found between performance indices of the RJT (IJ, TJ, and PD) and peak V[Combining Dot Above]O2. The findings suggest that a selection of repeated activity test protocols should acknowledge the specific technique used in the sport, and that a distinct RJT, rather than the classic RST, is more appropriate for assessing the anaerobic capabilities of volleyball players. The findings also suggest that aerobic fitness plays only a minor role in performance maintenance throughout characteristic repeated jumping activity of a volleyball game.

  15. Pharmaceutically active compounds in sludge stabilization treatments: anaerobic and aerobic digestion, wastewater stabilization ponds and composting.

    PubMed

    Martín, Julia; Santos, Juan Luis; Aparicio, Irene; Alonso, Esteban

    2015-01-15

    Sewage sludge disposal onto lands has been stabilized previously but still many pollutants are not efficiently removed. Special interest has been focused on pharmaceutical compounds due to their potential ecotoxicological effects. Nowadays, there is scarce information about their occurrence in different sludge stabilization treatments. In this work, the occurrence of twenty-two pharmaceutically active compounds has been studied in sludge from four sludge stabilization treatments: anaerobic digestion, aerobic digestion, composting and lagooning. The types of sludge evaluated were primary, secondary, anaerobically-digested and dehydrated, composted, mixed, aerobically-digested and dehydrated and lagoon sludge. Nineteen of the twenty-two pharmaceutically active compounds monitored were detected in sewage sludge. The most contaminated samples were primary sludge, secondary sludge and mixed sludge (the average concentrations of studied compounds in these sludges were 179, 310 and 142 μg/kg dm, respectively) while the mean concentrations found in the other types of sewage sludge were 70 μg/kg dm (aerobically-digested sludge), 63 μg/kg dm (lagoon sludge), 12 μg/kg dm (composted sludge) and 8 μg/kg dm (anaerobically-digested sludge). The antibiotics ciprofloxacin and norfloxacin were found at the highest concentration levels in most of the analyzed sludge samples (up to 2660 and 4328 μg/kg dm, respectively). Anaerobic-digestion treatment reduced more considerably the concentration of most of the studied compounds than aerobic-digestion (especially in the case of bezafibrate and fluoroquinolones) and more than anaerobic stabilization ponds (in the case of acetaminophen, atenolol, bezafibrate, carbamazepine, 17α-ethinylestradiol, naproxen and salicylic acid). Ecotoxicological risk assessment, of sludge application onto soils, has also been evaluated. Risk quotients, expressed as the ratio between the predicted environmental concentration and the predicted non

  16. Acidophilic Methanotrophic Communities from Sphagnum Peat Bogs

    PubMed Central

    Dedysh, Svetlana N.; Panikov, Nicolai S.; Tiedje, James M.

    1998-01-01

    Highly enriched methanotrophic communities (>25 serial transfers) were obtained from acidic ombrotrophic peat bogs from four boreal forest sites. The enrichment strategy involved using media conditions that were associated with the highest rates of methane uptake by the original peat samples, namely, the use of diluted mineral medium of low buffering capacity, moderate incubation temperature (20°C), and pH values of 3 to 6. Enriched communities contained a mixture of rod-shaped bacteria arranged in aggregates with a minor contribution of Hyphomicrobium-like cells. The growth stoichiometry of isolates was characteristic of methanotrophic bacteria (CH4/O2/CO2=1:1.1:0.59), with an average apparent yield of 0.41 ± 0.03 g of biomass C/g of CH4-C. DNA from each enrichment yielded a PCR product of the expected size with primers for both mmoX and mmoY genes of soluble methane monooxygenase. Two types of sequences were obtained for PCR-amplified fragments of mmoX. One of them exhibited high identity to the mmoX protein of the Methylocystis-Methylosinus group, whereas the other showed an equal level of divergence from both the Methylosinus-Methylocystis group and Methylococcus capsulatus (Bath) and formed a distinct branch. The pH optimum for growth and for CH4 uptake was 4.5 to 5.5, which is very similar to that for the optimum CH4 uptake observed in the original peat samples. These methanotrophs are moderate acidophiles rather than acidotolerant organisms, since their growth rate and methane uptake were much lower at neutral pH. The growth of the methanotrophic community was enhanced by using media with a very low salt content (20 to 200 mg/liter), more typical of their natural environment. All four enriched communities grew on N-free medium. PMID:9501432

  17. Niche differentiation in nitrogen metabolism among methanotrophs within an operational taxonomic unit

    PubMed Central

    2014-01-01

    Background The currently accepted thesis on nitrogenous fertilizer additions on methane oxidation activity assumes niche partitioning among methanotrophic species, with activity responses to changes in nitrogen content being dependent on the in situ methanotrophic community structure Unfortunately, widely applied tools for microbial community assessment only have a limited phylogenetic resolution mostly restricted to genus level diversity, and not to species level as often mistakenly assumed. As a consequence, intragenus or intraspecies metabolic versatility in nitrogen metabolism was never evaluated nor considered among methanotrophic bacteria as a source of differential responses of methane oxidation to nitrogen amendments. Results We demonstrated that fourteen genotypically different Methylomonas strains, thus distinct below the level at which most techniques assign operational taxonomic units (OTU), show a versatile physiology in their nitrogen metabolism. Differential responses, even among strains with identical 16S rRNA or pmoA gene sequences, were observed for production of nitrite and nitrous oxide from nitrate or ammonium, nitrogen fixation and tolerance to high levels of ammonium, nitrate, and hydroxylamine. Overall, reduction of nitrate to nitrite, nitrogen fixation, higher tolerance to ammonium than nitrate and tolerance and assimilation of nitrite were general features. Conclusions Differential responses among closely related methanotrophic strains to overcome inhibition and toxicity from high nitrogen loads and assimilation of various nitrogen sources yield competitive fitness advantages to individual methane-oxidizing bacteria. Our observations proved that community structure at the deepest phylogenetic resolution potentially influences in situ functioning. PMID:24708438

  18. Activity, distribution, and abundance of methane-oxidizing bacteria in the near surface soils of onshore oil and gas fields.

    PubMed

    Xu, Kewei; Tang, Yuping; Ren, Chun; Zhao, Kebin; Wang, Wanmeng; Sun, Yongge

    2013-09-01

    Methane-oxidizing bacteria (MOB) have long been used as an important biological indicator for oil and gas prospecting, but the ecological characteristics of MOB in hydrocarbon microseep systems are still poorly understood. In this study, the activity, distribution, and abundance of aerobic methanotrophic communities in the surface soils underlying an oil and gas field were investigated using biogeochemical and molecular ecological techniques. Measurements of potential methane oxidation rates and pmoA gene copy numbers showed that soils inside an oil and gas field are hot spots of methane oxidation and MOB abundance. Correspondingly, terminal restriction fragment length polymorphism analyses in combination with cloning and sequencing of pmoA genes also revealed considerable differences in the methanotrophic community composition between oil and gas fields and the surrounding soils. Principal component analysis ordination furthermore indicated a coincidence between elevated CH4 oxidation activity and the methanotrophic community structure with type I methanotrophic Methylococcus and Methylobacter, in particular, as indicator species of oil and gas fields. Collectively, our results show that trace methane migrated from oil and gas reservoirs can considerably influence not only the quantity but also the structure of the methanotrophic community.

  19. Acute effects of aerobic stretching, health and happiness improving movement exercise on cortical activity of children.

    PubMed

    Choi, Hyungsoo; Park, Sangjun; Kim, Kyekyoon Kevin; Lee, Kwanghee; Rhyu, Hyun-Seung

    2016-08-01

    Acute high-intensity physical exercise is known to improve cognitive performance of children, including those with attention-deficit/hyperactivity disorder (ADHD). In this work, we investigated the acute effect of an aerobic stretching and moderate-intensity, health and happiness improving movement (HHIM) exercise on the cortical activity of children with and without ADHD using electroencephalography (EEG). Children aged 12 to 14 yr with combined-type ADHD and age-matched healthy controls participated in the study, performing two individual movements (n=79, 35 controls) and a single exercise bout (n=45, 18 controls). electroencephalographic signals were recorded before and immediately after each movement, and before and after acute exercise under resting conditions, to obtain absolute and relative power estimates for the theta (3.5-8 Hz), alpha (8-12 Hz), sensory motor rhythm (12-16 Hz), and beta (16-25 Hz) bands. After acute HHIM exercise, all children showed significant changes in their relative EEG, mainly in the theta and alpha bands. Individual movements were found to influence relative theta, alpha and beta, and theta-to-beta ratios. He presents aerobic stretching HHIM exercise has demonstrated acute effect on the cortical activity of children.

  20. Analyses of spatial distributions of sulfate-reducing bacteria and their activity in aerobic wastewater biofilms

    SciTech Connect

    Okabe, Satoshi; Itoh, Tsukasa; Satoh, Hisashi; Watanabe, Yoshimasa

    1999-11-01

    The vertical distribution of sulfate-reducing bacteria (SRB) in aerobic wastewater biofilms grown on rotating disk reactors was investigated by fluorescent in situ hybridization (FISH) with 16S rRNA-targeted oligonucleotide probes. To correlate the vertical distribution of SRB populations with their activity, the microprofiles of O{sub 2}, H{sub 2}S, NO{sub 2}{minus}, NH{sub 2}{sup +}, and pH were measured with microelectrodes. In addition, a cross-evaluation of the FISH and microelectrode analyses was performed by comparing them with culture-based approaches and biogeochemical measurements. In situ hybridization revealed that a relatively high abundance of the probe SRB385-stained cells were evenly distributed throughout the biofilm, even in the toxic surface. The probe SRB660-stained Desulfobulbus spp. were found to be numerically important members of SRB populations. The result of microelectrode measurements showed that a high sulfate-reducing activity was found in a narrow anaerobic zone located about 150 to 300 {micro}m below the biofilm surface and above which an intensive sulfide oxidation zone was found. The biogeochemical measurements showed that elemental sulfur (S{degree}) was an important intermediate of the sulfide reoxidation in such thin wastewater biofilms, which accounted for about 75% of the total S pool in the biofilm. The contribution of an internal Fe-sulfur cycle to the overall sulfur cycle in aerobic wastewater biofilms was insignificant (less than 1%) due to the relatively high sulfate reduction rate.

  1. Acid-Tolerant Moderately Thermophilic Methanotrophs of the Class Gammaproteobacteria Isolated From Tropical Topsoil with Methane Seeps

    PubMed Central

    Islam, Tajul; Torsvik, Vigdis; Larsen, Øivind; Bodrossy, Levente; Øvreås, Lise; Birkeland, Nils-Kåre

    2016-01-01

    Terrestrial tropical methane seep habitats are important ecosystems in the methane cycle. Methane oxidizing bacteria play a key role in these ecosystems as they reduce methane emissions to the atmosphere. Here, we describe the isolation and initial characterization of two novel moderately thermophilic and acid-tolerant obligate methanotrophs, assigned BFH1 and BFH2 recovered from a tropical methane seep topsoil habitat. The new isolates were strictly aerobic, non-motile, coccus-shaped and utilized methane and methanol as sole carbon and energy source. Isolates grew at pH range 4.2–7.5 (optimal 5.5–6.0) and at a temperature range of 30–60°C (optimal 51–55°C). 16S rRNA gene phylogeny placed them in a well-separated branch forming a cluster together with the genus Methylocaldum as the closest relatives (93.1–94.1% sequence similarity). The genes pmoA, mxaF, and cbbL were detected, but mmoX was absent. Strains BFH1 and BFH2 are, to our knowledge, the first isolated acid-tolerant moderately thermophilic methane oxidizers of the class Gammaproteobacteria. Each strain probably denotes a novel species and they most likely represent a novel genus within the family Methylococcaceae of type I methanotrophs. Furthermore, the isolates increase our knowledge of acid-tolerant aerobic methanotrophs and signify a previously unrecognized biological methane sink in tropical ecosystems. PMID:27379029

  2. Identification of Methanotrophic Biomarker Lipids in the Symbiont-Containing Gills of Seep Mussels

    NASA Technical Reports Server (NTRS)

    Jahnke, L. L.; Zahiralis, K. D.; Klein, H. P.; Morrison, David (Technical Monitor)

    1994-01-01

    Mussels collected from hydrocarbon seeps in the Gulf of Mexico grow with methane as sole carbon and energy source due to a symbiotic association with methane-oxidizing bacteria. Transmission electron micrographs of mussel gills show cells with stacked intracytoplasmic membranes similar to type I methanotrophic bacteria. Methanotrophs are known to synthesize several types of cyclic triterpenes, hopanoids and methyl sterols, as well as unique monounsaturated fatty acid, double bond positional isomers that serve as biomarkers for this group. Lipid analysis of dissected mussels demonstrated the presence of these biomarkers predominantly in the gill tissue with much smaller amounts in mantle and remaining body tissues. Gill tissue contained 1150 micrograms/g dry wt. of hopanepolyol derivatives and diplopterol while the mantle tissue contained only 17 micrograms/g. The C16 monounsaturated fatty acids (16:1) characteristic of type I methanotrophic membranes dominated the gill tissue making up 53% of the total while only 5% 16:1 was present in the mantle tissue. The methyl sterol distribution was more dispersed. The predominant sterol in all tissues was cholesterol with lesser amounts of other desmethyl and 4-methyl sterols. The gill and mantle tissues contained 3461 micrograms (17% methyl) and 2750 micrograms (5% methyl) sterol per gm dry wt., respectively. Methyl sterol accounted for 44% of the sterol esters isolated from the gill, suggesting active demethylation of the methanotrophic sterols in this tissue. The use of lipid biomarkers could provide an effective means for identifying host-symbiont relationships.

  3. 6:2 fluorotelomer sulfonate aerobic biotransformation in activated sludge of waste water treatment plants.

    PubMed

    Wang, Ning; Liu, Jinxia; Buck, Robert C; Korzeniowski, Stephen H; Wolstenholme, Barry W; Folsom, Patrick W; Sulecki, Lisa M

    2011-02-01

    The aerobic biotransformation of 6:2 FTS salt [F(CF2)6CH2CH2SO3- K+] was determined in closed bottles for 90d in diluted activated sludge from three waste water treatment plants (WWTPs) to compare its biotransformation potential with that of 6:2 FTOH [F(CF2)6CH2CH2OH]. The 6:2 FTS biotransformation was relatively slow, with 63.7% remaining at day 90 and all observed transformation products together accounting for 6.3% of the initial 6:2 FTS applied. The overall mass balance (6:2 FTS plus observed transformation products) at day 90 in live and sterile treatments averaged 70% and 94%, respectively. At day 90, the stable transformation products observed were 5:3 acid [F(CF2)5CH2CH2COOH, 0.12%], PFBA [F(CF2)3COOH, 0.14%], PFPeA [F(CF2)4COOH, 1.5%], and PFHxA [F(CF2)5COOH 1.1%]. In addition, 5:2 ketone [F(CF2)5C(O)CH3] and 5:2 sFTOH [F(CF2)5CH(OH)CH3] together accounted for 3.4% at day 90. The yield of all the stable transformation products noted above (2.9%) was 19 times lower than that of 6:2 FTOH in aerobic soil. Thus 6:2 FTS is not likely to be a major source of PFCAs and polyfluorinated acids in WWTPs. 6:2 FTOH, 6:2 FTA [F(CF2)6CH2COOH], and PFHpA [F(CF2)6COOH] were not observed during the 90-d incubation. 6:2 FTS primary biotransformation bypassed 6:2 FTOH to form 6:2 FTUA [F(CF2)5CF=CHCOOH], which was subsequently degraded via pathways similar to 6:2 FTOH biotransformation. A substantial fraction of initially dosed 6:2 FTS (24%) may be irreversibly bound to diluted activated sludge catalyzed by microbial enzymes. The relatively slow 6:2 FTS degradation in activated sludge may be due to microbial aerobic de-sulfonation of 6:2 FTS, required for 6:2 FTS further biotransformation, being a rate-limiting step in microorganisms of activated sludge in WWTPs.

  4. Aerobic and resistance training do not influence plasma carnosinase content or activity in type 2 diabetes.

    PubMed

    Stegen, Sanne; Sigal, Ronald J; Kenny, Glen P; Khandwala, Farah; Yard, Benito; De Heer, Emile; Baelde, Hans; Peersman, Wim; Derave, Wim

    2015-10-01

    A particular allele of the carnosinase gene (CNDP1) is associated with reduced plasma carnosinase activity and reduced risk for nephropathy in diabetic patients. On the one hand, animal and human data suggest that hyperglycemia increases plasma carnosinase activity. On the other hand, we recently reported lower carnosinase activity levels in elite athletes involved in high-intensity exercise compared with untrained controls. Therefore, this study investigates whether exercise training and the consequent reduction in hyperglycemia can suppress carnosinase activity and content in adults with type 2 diabetes. Plasma samples were taken from 243 males and females with type 2 diabetes (mean age = 54.3 yr, SD = 7.1) without major microvascular complications before and after a 6-mo exercise training program [4 groups: sedentary control (n = 61), aerobic exercise (n = 59), resistance exercise (n = 63), and combined exercise training (n = 60)]. Plasma carnosinase content and activity, hemoglobin (Hb) A1c, lipid profile, and blood pressure were measured. A 6-mo exercise training intervention, irrespective of training modality, did not decrease plasma carnosinase content or activity in type 2 diabetic patients. Plasma carnosinase content and activity showed a high interindividual but very low intraindividual variability over the 6-mo period. Age and sex, but not Hb A1c, were significantly related to the activity or content of this enzyme. It can be concluded that the beneficial effects of exercise training on the incidence of diabetic complications are probably not related to a lowering effect on plasma carnosinase content or activity.

  5. Effect of nitrogen fertilization on methane oxidation, abundance, community structure, and gene expression of methanotrophs in the rice rhizosphere.

    PubMed

    Shrestha, Minita; Shrestha, Pravin Malla; Frenzel, Peter; Conrad, Ralf

    2010-12-01

    Nitrogen, one of the limiting factors for the yield of rice, can also have an important function in methane oxidation, thus affecting its global budget. Rice microcosms, planted in the greenhouse, were treated with the N-fertilizers urea (UPK) and ammonium sulfate (APK) or were only treated with phosphorous and potassium (PK). Methane oxidation rates in PK and UPK treatments were similar during most of the rice-growing season, revealing no effect of urea. However, ammonium sulfate strongly suppressed methanogenesis providing an unfavorable environment for methanotrophs in APK treatment. Roots and rhizospheric soil samples, collected from six different growth stages of the rice plant, were analyzed by terminal restriction fragment length polymorphism (T-RFLP) of the pmoA gene. Assignment of abundant T-RFs to cloned pmoA sequences indicated that the populations on roots were dominated by type-I methanotrophs, whereas the populations in rhizospheric soil were dominated by type-II methanotrophs irrespectively of growth stages and fertilizer treatments. Non-metric multidimensional scaling ordination analysis of T-RFLP profiles revealed that the methanotrophic community was significantly (P<0.001) affected by the different fertilizer treatments; however, the effect was stronger on the roots than in the rhizospheric soil. Contrary to pmoA gene-based analysis, pmoA transcript-based T-RFLP/cloning/sequencing analysis in rhizospheric soil showed type I as the predominant methanotrophs in both PK and UPK treatments. Collectively, our study showed that type-I methanotrophs were dominant and probably active in rhizospheric soil throughout the season irrespective of nitrogen fertilizer used, whereas type-II methanotrophs were relatively more dominant under unfavorable conditions, such as in APK treatment.

  6. High diversity of methanotrophic bacteria in geothermal soils affected by high methane fluxes

    NASA Astrophysics Data System (ADS)

    D'Alessandro, Walter; Gagliano, Antonina Lisa; Quatrini, Paola; Parello, Francesco

    2014-05-01

    Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas 25 times as potent as CO2. Recently, it has been demonstrated that volcanic/geothermal soils act as source, but also as biological filter for methane release to the atmosphere. For long time, volcanic/geothermal soils has been considered inhospitable for methanotrophic microorganisms, but new extremophile methanotrophs belonging to Verrucomicrobia were identified in three different areas (Pozzuoli, Italy; Hell's Gate, New Zealand; Kamchatka, Russia), explaining anomalous behaviours in methane leakages of several geothermal/volcanic sites. Our aim was to increase the knowledge of the relationship between methane emissions from volcanic/geothermal areas and biological methane oxidation, by investigating a geothermal site of Pantelleria island (Italy). Pantelleria Island hosts a high enthalpy geothermal system characterized by high temperature, high CH4 and very low H2S fluxes. Such characteristics are reflected in potentially great supply of methane for methanotrophs and scarce presence of inhibitors of their activity (H2S and NH3) in the Pantelleria soils. Potential methanotrophic activity within these soils was already evidenced by the CH4/CO2 ratio of the flux measurements which was lower than that of the respective fumarolic manifestations indicating a loss of CH4 during the gas travel towards the earth's surface. In this study laboratory incubation experiments using soils sampled at Favara Grande, the main hydrothermal area of Pantelleria, showed very high methane consumption rates (up to 9500 ng CH4 h-1 g-1). Furthermore, microbiological and culture-independent molecular analyses allowed to detect the presence of methanotrophs affiliated to Gamma- and Alpha-Proteobacteria and to the newly discovered acidothermophilic methanotrophs Verrucomicrobia. Culturable methanotrophic Alpha-proteobacteria of the genus Methylocystis were isolated by

  7. The intervention composed of aerobic training and non-exercise physical activity (I-CAN) study: Rationale, design and methods.

    PubMed

    Swift, Damon L; Dover, Sara E; Nevels, Tyara R; Solar, Chelsey A; Brophy, Patricia M; Hall, Tyler R; Houmard, Joseph A; Lutes, Lesley D

    2015-11-01

    Recent data has suggested that prolonged sedentary behavior is independent risk factor for cardiovascular and all-cause mortality independent of adequate amounts of moderate to vigorous physical activity. However, few studies have prospectively evaluated if exercise training and increasing non-exercise physical activity leads to greater reduction in cardiometabolic risk compared to aerobic training alone. The purpose of the Intervention Composed of Aerobic Training and Non-Exercise Physical Activity (I-CAN) study is to determine whether a physical activity program composed of both aerobic training (consistent with public health recommendations) and increasing non-exercise physical activity (3000 steps above baseline levels) leads to enhanced improvements in waist circumference, oral glucose tolerance, systemic inflammation, body composition, and fitness compared to aerobic training alone in obese adults (N=45). Commercially available accelerometers (Fitbits) will be used to monitor physical activity levels and behavioral coaching will be used to develop strategies of how to increase non-exercise physical activity levels. In this manuscript, we describe the design, rationale, and methodology associated with the I-CAN study.

  8. Methanotrophic bacteria and facilitated transport of pollutants in aquifer material

    SciTech Connect

    Jenkins, M.B.; Chen, Jyh-Herng; Kadner, D.J.; Lion, L.W. )

    1994-10-01

    In-situ stimulation of methanotrophic bacteria has been considered for aquifer remediation. Experimental results indicate that both colloidal suspensions containing methanotrophic cells and the soluble extracellular polymers produced by methanotrophic cells have the potential to enhance the transport and removal of other environmental contaminants such as polynuclear aromatic hydrocarbons and transition metals in aquifer material. Three methanotrophic bacteria were used in the experiments: Methylomonas albus BG8, Methylosinus trichosporium OB3b, and Methylocystis parvus OBBP. The distribution coefficients for Cd with extraceullular polymers were of the same order as that obtained with the aquifer sand, indicating polymers from the methanotrophic bacteria could act to increase the transport of Cd in a porous medium. Polymer from BG8 significantly reduced the apparent distribution coefficient for Cd with an aquifer sand. [[sup 14]C]phenanthrene also sorbed to extracellular polymer and to washed, suspended methanotrophic cells. The exopolymer of BG8 and OBBP significantly reduced the apparent distribution coefficient (K[sub d]) for phenanthrene with aquifer sand. The distribution coefficients for phenanthrene with the methanotrophic cells were an order of magnitude greater than those previously reported for other heterotrophic bacteria. Cells of the methanotrophs also significantly reduced the apparent K[sub d] for phenanthrene with an aquifer sand. The three strains of methanotrophs displayed mobility in a column of packed sand, and strain OBBP reduced the retardation coefficient of phenanthrene with an aquifer sand by 27%. These data indicate that both extracellular polymer and mobile cells of methanotrophic bacteria display a capacity to facilitate the mobility of pollutant metals and polynuclear aromatic hydrocarbons in aquifer material. 48 refs., 3 figs., 4 tabs.

  9. Dance--Aerobic and Anaerobic.

    ERIC Educational Resources Information Center

    Cohen, Arlette

    1984-01-01

    This article defines and explains aerobic exercise and its effects on the cardiovascular system. Various studies on dancers are cited indicating that dance is an anaerobic activity with some small degree of aerobic benefit. (DF)

  10. Vigorous, Aerobic Exercise versus General Motor Training Activities: Effects on Maladaptive and Stereotypic Behaviors of Adults with Both Autism and Mental Retardation.

    ERIC Educational Resources Information Center

    Elliott, Reed O., Jr.; And Others

    1994-01-01

    Six adults with both autism and moderate/profound mental retardation were assessed in a controlled environment for changes in frequency of maladaptive and stereotypic behaviors following nonexercise activities, general motor training activities, and aerobic exercise. Although antecedent aerobic exercise reduced undesirable behaviors, general motor…

  11. Effects of active recovery on autonomic and haemodynamic responses after aerobic exercise.

    PubMed

    Soares, Antonio H G; Oliveira, Tiago P; Cavalcante, Bruno R; Farah, Breno Q; Lima, Aluísio H R A; Cucato, Gabriel G; Cardoso, Crivaldo G; Ritti-Dias, Raphael M

    2017-01-01

    The aim of this study was to examine the effect of active recovery on autonomic and haemodynamic responses after exercise in healthy adults. Nineteen healthy young male individuals underwent two experimental sessions: exercise with active recovery (AR) and exercise with passive recovery (PR). The exercise sessions comprised three phases: warm-up (5 min), exercise phase (cycle ergometer, 30 min, intensity between 60 and 70% of the heart rate reserve) and recovery (5 min). In the AR, the subjects remained cycling in the recovery phase at intensity between 30% and 35% of heart rate reserve, while in the PR, the subjects stopped the exercise after finishing the exercise phase. Blood pressure and heart rate were measured before and over the 30 min after the interventions. There were no differences for systolic and diastolic blood pressures, heart rate and rate pressure product between active and passive recovery sessions. Also, all heart rate variability parameters changed similarly after exercise with passive or active recovery sessions. In summary, exercise with active recovery does not affect the autonomic and haemodynamic responses after moderate-intensity aerobic exercise in healthy young male individuals.

  12. Methanotrophic gastropods from a bathyal hydrocarbon seep, Gulf of Mexico

    SciTech Connect

    Anderson, L.C.; Aharon, P.; Gupta, S. )

    1992-01-01

    Two gastropods, Neritina sp. and Truncatella sp., collected live from a Gulf of Mexico active gas seep with the submersible Johnson Sea Link in September 1991, apparently incorporate methane-derived carbon in their soft tissues. Flesh of an individual Neritina sp. had a delta C-13 of [minus]50.92 per mil PDB, and that of two coexisting individuals of Truncatella sp. had values of [minus]45.11 and [minus]49.27 per mil. These isotope values are comparable to those reported for the methanotrophic mytilid bivalve Bathymodiolus sp. from other hydrocarbon seeps on the Gulf of Mexico, and are lighter than published isotopic values of chemosynthetic organisms with sulfur-oxidizing symbionts. The anomalously light carbon-isotopic values of Neritina sp. and Truncatella sp. may steam from one of three causes: (1) these gastropods host symbiotic methanotrophic bacteria, (2) their chief food is methane-oxidizing bacteria present at the seep, or (3) they incorporate some carbon from the periostracum of mussels on which they may graze. The presence of abundant juveniles of Bathymodiolus, reported to settle preferentially in areas of active seepage and high methane release, indicates that methane was abundant and supported a community with multiple trophic levels. Generally, studies of hydrocarbon-seep communities have focused on larger community members, especially bivalves and tube worms. The presence of living Neritina and Truncatella at the authors sampling site, however, draws attention to the fact that these gastropods are integral and significant parts of hydrocarbon-seep communities. Both gastropod species are members of genera that characteristically inhabit shallow marine, intertidal, and semiterrestrial environments. The presence of these genera in bathyal hydrocarbon seeps indicates that they have very broad environmental ranges, thus limiting their utility in paleoecologic reconstructions.

  13. Intercellular wiring enables electron transfer between methanotrophic archaea and bacteria.

    PubMed

    Wegener, Gunter; Krukenberg, Viola; Riedel, Dietmar; Tegetmeyer, Halina E; Boetius, Antje

    2015-10-22

    The anaerobic oxidation of methane (AOM) with sulfate controls the emission of the greenhouse gas methane from the ocean floor. In marine sediments, AOM is performed by dual-species consortia of anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB) inhabiting the methane-sulfate transition zone. The biochemical pathways and biological adaptations enabling this globally relevant process are not fully understood. Here we study the syntrophic interaction in thermophilic AOM (TAOM) between ANME-1 archaea and their consortium partner SRB HotSeep-1 (ref. 6) at 60 °C to test the hypothesis of a direct interspecies exchange of electrons. The activity of TAOM consortia was compared to the first ANME-free culture of an AOM partner bacterium that grows using hydrogen as the sole electron donor. The thermophilic ANME-1 do not produce sufficient hydrogen to sustain the observed growth of the HotSeep-1 partner. Enhancing the growth of the HotSeep-1 partner by hydrogen addition represses methane oxidation and the metabolic activity of ANME-1. Further supporting the hypothesis of direct electron transfer between the partners, we observe that under TAOM conditions, both ANME and the HotSeep-1 bacteria overexpress genes for extracellular cytochrome production and form cell-to-cell connections that resemble the nanowire structures responsible for interspecies electron transfer between syntrophic consortia of Geobacter. HotSeep-1 highly expresses genes for pili production only during consortial growth using methane, and the nanowire-like structures are absent in HotSeep-1 cells isolated with hydrogen. These observations suggest that direct electron transfer is a principal mechanism in TAOM, which may also explain the enigmatic functioning and specificity of other methanotrophic ANME-SRB consortia.

  14. Effect of Cardiorespiratory Training on Aerobic Fitness and Carryover to Activity In Children with Cerebral Palsy: A Systematic Review

    ERIC Educational Resources Information Center

    Butler, Jane M.; Scianni, Aline; Ada, Louise

    2010-01-01

    The question under consideration was does cardiorespiratory training improve aerobic fitness in children with cerebral palsy and is there any carryover into activity? The study design consisted of a systematic review of randomized trials using the Cochrane Collaboration guidelines. Participants were children of school age with cerebral palsy.…

  15. Intraspecific variation in aerobic metabolic rate of fish: relations with organ size and enzyme activity in brown trout.

    PubMed

    Norin, Tommy; Malte, Hans

    2012-01-01

    Highly active animals require a high aerobic capacity (i.e., a high maximum metabolic rate [MMR]) to sustain such activity, and it has been speculated that a greater capacity for aerobic performance is reflected in larger organs, which serve as energy processors but are also expensive to maintain and which increase the minimal cost of living (i.e., the basal or standard metabolic rate [SMR]). In this study, we assessed the extent of intraspecific variation in metabolic rate within a group of brown trout (Salmo trutta L.) and tested whether the observed variation in residual (body-mass-corrected) SMR, MMR, and absolute aerobic scope could be explained by variations in the residual size (mass) of metabolically active internal organs. Residual SMR was found to correlate positively with residual MMR, indicating a link between these two metabolic parameters, but no relationship between organ mass and metabolic rate was found for liver, heart, spleen, intestine, or stomach. Instead, activity in the liver of two aerobic mitochondrial enzymes, cytochrome c oxidase and, to a lesser extent, citrate synthase, was found to correlate with whole-animal metabolic rate, indicating that causes for intraspecific variation in the metabolic rate of fish can be found at a lower organizational level than organ size.

  16. Active Female Maximal and Anaerobic Threshold Cardiorespiratory Responses to Six Different Water Aerobics Exercises

    ERIC Educational Resources Information Center

    Antunes, Amanda H.; Alberton, Cristine L.; Finatto, Paula; Pinto, Stephanie S.; Cadore, Eduardo L.; Zaffari, Paula; Kruel, Luiz F. M.

    2015-01-01

    Purpose: Maximal tests conducted on land are not suitable for the prescription of aquatic exercises, which makes it difficult to optimize the intensity of water aerobics classes. The aim of the present study was to evaluate the maximal and anaerobic threshold cardiorespiratory responses to 6 water aerobics exercises. Volunteers performed 3 of the…

  17. Association of Occupational and Leisure-Time Physical Activity with Aerobic Capacity in a Working Population

    PubMed Central

    Mundwiler, Jonas; Schüpbach, Ulla; Dieterle, Thomas; Leuppi, Jörg Daniel; Schmidt-Trucksäss, Arno; Wolfer, David Paul; Miedinger, David; Brighenti-Zogg, Stefanie

    2017-01-01

    Introduction Objective data on the association of maximal aerobic capacity (VO2max) with work related physical activity are sparse. Thus, it is not clear whether occupational physical activity (OPA) contributes to an increase of VO2max. This study examined the association of VO2max with work and non-work related physical activity in a Swiss working population. Methods In this cross-sectional study, a total of 337 healthy and full-time employed adults were recruited. Demographic data, height, weight and BMI were recorded in all subjects. Participants were classified into nine occupational categories (ISCO-88) and merged into three groups with low, moderate, and high OPA. Physical activity was objectively measured by the SenseWear Mini Armband on seven consecutive days (23 hours per day). Participants were regarded as sufficiently active when accumulating ≥30 min of moderate-to-vigorous physical activity per day. VO2max was evaluated using the multistage 20-meter shuttle run test. Results Data of 303 participants were considered for analysis (63% male, age 33 yrs, SD 12). Multiple linear regression analysis (adjusted R2 = 0.69) revealed significant positive associations of VO2max with leisure-time physical activity (LTPA) at vigorous intensity (β = 0.212) and sufficient moderate-to-vigorous physical activity (β = 0.100) on workdays. Female gender (β = -0.622), age (β = -0.264), BMI (β = -0.220), the ratio of maximum to resting heart rate (β = 0.192), occupational group (low vs. high OPA, β = -0.141), and smoking (β = -0.133) were also identified as independent predictors of VO2max. Conclusions The present results suggest that VO2max is positively associated with LTPA, but not with OPA on workdays. This finding emphasizes the need for employees to engage in sufficient high-intensity physical activity in recreation for maintaining or improving VO2max with regard to health benefits. PMID:28045939

  18. Detection, isolation, and characterization of acidophilic methanotrophs from Sphagnum mosses.

    PubMed

    Kip, Nardy; Ouyang, Wenjing; van Winden, Julia; Raghoebarsing, Ashna; van Niftrik, Laura; Pol, Arjan; Pan, Yao; Bodrossy, Levente; van Donselaar, Elly G; Reichart, Gert-Jan; Jetten, Mike S M; Damsté, Jaap S Sinninghe; Op den Camp, Huub J M

    2011-08-15

    Sphagnum peatlands are important ecosystems in the methane cycle. Methane-oxidizing bacteria in these ecosystems serve as a methane filter and limit methane emissions. Yet little is known about the diversity and identity of the methanotrophs present in and on Sphagnum mosses of peatlands, and only a few isolates are known. The methanotrophic community in Sphagnum mosses, originating from a Dutch peat bog, was investigated using a pmoA microarray. A high biodiversity of both gamma- and alphaproteobacterial methanotrophs was found. With Sphagnum mosses as the inoculum, alpha- and gammaproteobacterial acidophilic methanotrophs were isolated using established and newly designed media. The 16S rRNA, pmoA, pxmA, and mmoX gene sequences showed that the alphaproteobacterial isolates belonged to the Methylocystis and Methylosinus genera. The Methylosinus species isolated are the first acid-tolerant members of this genus. Of the acidophilic gammaproteobacterial strains isolated, strain M5 was affiliated with the Methylomonas genus, and the other strain, M200, may represent a novel genus, most closely related to the genera Methylosoma and Methylovulum. So far, no acidophilic or acid-tolerant methanotrophs in the Gammaproteobacteria class are known. All strains showed the typical features of either type I or II methanotrophs and are, to the best of our knowledge, the first isolated (acidophilic or acid-tolerant) methanotrophs from Sphagnum mosses.

  19. [Abundance and diversity of methanotrophic Gammaproteobacteria in northern wetlands].

    PubMed

    Danilova, O V; Dedysh, S N

    2014-01-01

    Numeric abundance, identity and pH preferences of methanotrophic Gammaproteobacteria (type I methanotrophs) inhabiting the northern acidic wetlands were studied. The rates of methane oxidation by peat samples from six-wetlands of European Northern Russia (pH 3.9-4.7) varied from 0.04 to 0.60 μg CH4 g(-1) peat h(-1). The number of cells revealed by hybridization with fluorochrome-labeled probes M84 + M705 specific for type I methanotrophs was 0.05-2.16 x 10(5) cells g(-1) dry peat, i.e. 0.4-12.5% of the total number of methanotrophs and 0.004-0.39% of the total number of bacteria. Analysis of the fragments of the pmoA gene encoding particulate methane monooxygenase revealed predominance of the genus Methylocystis (92% of the clones) in the studied sample of acidic peat, while the proportion of the pmoA sequences of type I methanotrophs was insignificant (8%). PCR amplification of the 16S rRNA gene fragments of type I methanotrophs with TypeIF-Type IR primers had low specificity, since only three sequences out of 53 analyzed belonged to methanotrophs and exhibited 93-99% similarity to those of Methylovulum, Methylomonas, and Methylobacter species. Isolates of type I methanotrophs obtained from peat (strains SH10 and 83A5) were identified as members of the species Methylomonaspaludis and Methylovulum miyakonense, respectively. Only Methylomonaspaludum SH10 was capable of growth in acidic media (pH range for growth 3.8-7.2 with the optimum at pH 5.8-6.2), while Methylovulum miyakonense 83A5 exhibited the typical growth characteristics of neutrophilic methanotrophs (pH range for growth 5.5-8.0 with the optimum at pH 6.5-7.5).

  20. Weight training, aerobic physical activities, and long-term waist circumference change in men

    PubMed Central

    Mekary, Rania A.; Grøntved, Anders; Despres, Jean-Pierre; De Moura, Leandro Pereira; Asgarzadeh, Morteza; Willett, Walter C.; Rimm, Eric B.; Giovannucci, Edward; Hu, Frank B.

    2014-01-01

    Objective Findings on weight training and waist circumference (WC) change are controversial. This study examined prospectively whether weight training, moderate-to-vigorous aerobic activity (MVAA), and replacement of one activity for another were associated with favorable changes in WC and body weight (BW). Methods Physical activity, WC, and BW were reported in 1996 and 2008 in a cohort of 10,500 healthy U.S. men in the Health Professionals Follow-up Study. We used multiple linear regression models (partition/substitution) to assess these associations. Results After adjusting for potential confounders, we observed a significant inverse dose-response relationship between weight training and WC change (P-trend<0.001). Less age-associated WC increase was seen with a 20 min/day activity increase; this benefit was significantly stronger for weight training (-0.67cm, 95%CI -0.93, -0.41) than for MVAA (-0.33cm, 95%CI -0.40, -0.27), other activities (-0.16cm, 95%CI -0.28, -0.03), or TV watching (0.08cm, 95%CI 0.05, 0.12). Substituting 20 min/day of weight training for any other discretionary activity had the strongest inverse association with WC change. MVAA had the strongest inverse association with BW change (-0.23kg, 95%CI -0.29, -0.17). Conclusions Among various activities, weight training had the strongest association with less WC increase. Studies on frequency /volume of weight training and WC change are warranted. PMID:25530447

  1. [Continuous biosynthesis of epoxypropane in a methanotrophic attached-films reactor].

    PubMed

    Xin, Jia-Ying; Cui, Jun-Ru; Chen, Jian-Bo; Li, Shu-Ben; Xia, Chun-Gu

    2002-01-01

    Using a fluidized bed as immobilization system, mixed culture methanotrophic attached-films were developed on diatomite particles. The Methane Monooxygenase (MMO) activity was found to increase obviously as soon as the lag phase ended. Greater than 90% of the MMO activity in the bed was attached. Biofilm concentration of 3.3-3.7 mg dry weight cell/g DS was observed. Batch experiments were performed to explore the possibility of producing epoxypropane by a cooxidation process. The effect of methane on the oxidation of propene to epoxypropane and the effect of propene on the growth of methanotroph were also studied. In continuous experiments, optimum mixed gaseous substrates (methane: 35%; propene: 20%; oxygen: 45%) were continuously circulated through the fluidized bed reactor to remove product. Initial epoxypropane productivity was 110-150 mumol/d. The bioreactor operated continuously for 25 d without obvious loss of epoxypropane productivity.

  2. Conventional methanotrophs are responsible for atmospheric methane oxidation in paddy soils

    PubMed Central

    Cai, Yuanfeng; Zheng, Yan; Bodelier, Paul L. E.; Conrad, Ralf; Jia, Zhongjun

    2016-01-01

    Soils serve as the biological sink of the potent greenhouse gas methane with exceptionally low concentrations of ∼1.84 p.p.m.v. in the atmosphere. The as-yet-uncultivated methane-consuming bacteria have long been proposed to be responsible for this ‘high-affinity' methane oxidation (HAMO). Here we show an emerging HAMO activity arising from conventional methanotrophs in paddy soil. HAMO activity was quickly induced during the low-affinity oxidation of high-concentration methane. Activity was lost gradually over 2 weeks, but could be repeatedly regained by flush-feeding the soil with elevated methane. The induction of HAMO activity occurred only after the rapid growth of methanotrophic populations, and a metatranscriptome-wide association study suggests that the concurrent high- and low-affinity methane oxidation was catalysed by known methanotrophs rather than by the proposed novel atmospheric methane oxidizers. These results provide evidence of atmospheric methane uptake in periodically drained ecosystems that are typically considered to be a source of atmospheric methane. PMID:27248847

  3. Conventional methanotrophs are responsible for atmospheric methane oxidation in paddy soils

    NASA Astrophysics Data System (ADS)

    Cai, Yuanfeng; Zheng, Yan; Bodelier, Paul L. E.; Conrad, Ralf; Jia, Zhongjun

    2016-06-01

    Soils serve as the biological sink of the potent greenhouse gas methane with exceptionally low concentrations of ~1.84 p.p.m.v. in the atmosphere. The as-yet-uncultivated methane-consuming bacteria have long been proposed to be responsible for this `high-affinity' methane oxidation (HAMO). Here we show an emerging HAMO activity arising from conventional methanotrophs in paddy soil. HAMO activity was quickly induced during the low-affinity oxidation of high-concentration methane. Activity was lost gradually over 2 weeks, but could be repeatedly regained by flush-feeding the soil with elevated methane. The induction of HAMO activity occurred only after the rapid growth of methanotrophic populations, and a metatranscriptome-wide association study suggests that the concurrent high- and low-affinity methane oxidation was catalysed by known methanotrophs rather than by the proposed novel atmospheric methane oxidizers. These results provide evidence of atmospheric methane uptake in periodically drained ecosystems that are typically considered to be a source of atmospheric methane.

  4. Aerobic and anaerobic changes with high-intensity interval training in active college-aged men.

    PubMed

    Ziemann, Ewa; Grzywacz, Tomasz; Łuszczyk, Marcin; Laskowski, Radoslaw; Olek, Robert A; Gibson, Ann L

    2011-04-01

    We investigated the aerobic and anaerobic benefits of high-intensity interval training performed at a work-to-rest ratio of 1:2 because little performance enhancement data exist based on this ratio. Recreationally active male volunteers (21 years, 184 cm, 81.5 kg) were randomly assigned to a training (interval training [IT] n = 10) or control group (n = 11). Baseline assessments were repeated after the last training session. Each participant underwent basic anthropometric assessment and performed a VO2max test on an electronically braked cycle ergometer and a 30-second Wingate test. Venous samples were acquired at the antecubital vein and subsequently processed for lactate (LA); samples were obtained at rest, and 5 and 15-minute post-Wingate test. The interval training used a cycling power output equivalent to 80% of VO2max (80% p VO2max) applied for 6 90-second bouts (each followed by 180-second rest) per session, 3 sessions per week, for 6 weeks. The control group maintained their normal routine for the 6-week period. Group × time repeated-measures analyses of variance revealed that IT improved VO2max (5.5 ml · kg(-1) · min), anaerobic threshold (3.8 ml · kg(-1) · min), work output (12.5 J · kg(-1)), glycolytic work (11.5 J · kg(-1)), mean power (0.3 W · kg), peak power (0.4 W · kg(-1)), and max power (0.4 W · kg(-1)); p < 0.05. Posttesting LA was lower on average for IT at the 5-minute mark but significantly so at the 15-minute mark. Twenty-seven minutes of cycling at 80% p VO2max applied with a work-to-rest ratio of 1:2 and spread over 3 sessions per week for 6 weeks provided sufficient stimulus to significantly improve markers of anaerobic and aerobic performance in recreationally active college-aged men. Inclusion of such a protocol into a training program may rapidly restore or improve a client's or athlete's maximal functional capacity.

  5. Poly-3-hydroxybutyrate metabolism in the type II methanotroph Methylocystis parvus OBBP.

    PubMed

    Pieja, Allison J; Sundstrom, Eric R; Criddle, Craig S

    2011-09-01

    Differences in carbon assimilation pathways and reducing power requirements among organisms are likely to affect the role of the storage polymer poly-3-hydroxybutyrate (PHB). Previous researchers have demonstrated that PHB functions as a sole growth substrate in aerobic cultures enriched on acetate during periods of carbon deficiency, but it is uncertain how C(1) metabolism affects the role of PHB. In the present study, the type II methanotroph Methylocystis parvus OBBP did not replicate using stored PHB in the absence of methane, even when all other nutrients were provided in excess. When PHB-rich cultures of M. parvus OBBP were deprived of carbon and nitrogen for 48 h, they did not utilize significant amounts of stored PHB, and neither cell concentrations nor concentrations of total suspended solids changed significantly. When methane and nitrogen both were present, PHB and methane were consumed simultaneously. Cells with PHB had significantly higher specific growth rates than cells lacking PHB. The addition of formate (a source of reducing power) to PHB-rich cells delayed PHB consumption, but the addition of glyoxylate (a source of C(2) units) did not. This and results from other researchers suggest that methanotrophic PHB metabolism is linked to the supply of reducing power as opposed to the supply of C(2) units for synthesis.

  6. Aerobic and anaerobic enzymatic activity of orange roughy (Hoplostethus atlanticus) and alfonsino (Beryx splendens) from the Juan Fernandez seamounts area.

    PubMed

    Saavedra, L M; Quiñones, R A; Gonzalez-Saldía, R R; Niklitschek, E J

    2016-06-01

    The aerobic and anaerobic enzymatic activity of two important commercial bathypelagic species living in the Juan Fernández seamounts was analyzed: alfonsino (Beryx splendens) and orange roughy (Hoplostethus atlanticus). These seamounts are influenced by the presence of an oxygen minimum zone (OMZ) located between 160 and 250 m depth. Both species have vertical segregation; alfonsino is able to stay in the OMZ, while orange roughy remains at greater depths. In this study, we compare the aerobic and anaerobic capacity of these species, measuring the activity of key metabolic enzymes in different body tissues (muscle, heart, brain and liver). Alfonsino has higher anaerobic potential in its white muscle due to greater lactate dehydrogenase (LDH) activity (190.2 μmol NADH min(-1) g ww(-1)), which is related to its smaller body size, but it is also a feature shared with species that migrate through OMZs. This potential and the higher muscle citrate synthase and electron transport system activities indicate that alfonsino has greater swimming activity level than orange roughy. This species has also a high MDH/LDH ratio in its heart, brain and liver, revealing a potential capacity to conduct aerobic metabolism in these organs under prolonged periods of environmental low oxygen conditions, preventing lactic acid accumulation. With these metabolic characteristics, alfonsino may have increased swimming activity to migrate and also could stay for a period of time in the OMZ. The observed differences between alfonsino and orange roughy with respect to their aerobic and anaerobic enzymatic activity are consistent with their characteristic vertical distributions and feeding behaviors.

  7. Effect of selected monoterpenes on methane oxidation, denitrification, and aerobic metabolism by bacteria in pure culture.

    PubMed

    Amaral, J A; Ekins, A; Richards, S R; Knowles, R

    1998-02-01

    Selected monoterpenes inhibited methane oxidation by methanotrophs (Methylosinus trichosporium OB3b, Methylobacter luteus), denitrification by environmental isolates, and aerobic metabolism by several heterotrophic pure cultures. Inhibition occurred to various extents and was transient. Complete inhibition of methane oxidation by Methylosinus trichosporium OB3b with 1.1 mM (-)-alpha-pinene lasted for more than 2 days with a culture of optical density of 0.05 before activity resumed. Inhibition was greater under conditions under which particulate methane monooxygenase was expressed. No apparent consumption or conversion of monoterpenes by methanotrophs was detected by gas chromatography, and the reason that transient inhibition occurs is not clear. Aerobic metabolism by several heterotrophs was much less sensitive than methanotrophy was; Escherichia coli (optical density, 0.01), for example, was not affected by up to 7.3 mM (-)-alpha-pinene. The degree of inhibition was monoterpene and species dependent. Denitrification by isolates from a polluted sediment was not inhibited by 3.7 mM (-)-alpha-pinene, gamma-terpinene, or beta-myrcene, whereas 50 to 100% inhibition was observed for isolates from a temperate swamp soil. The inhibitory effect of monoterpenes on methane oxidation was greatest with unsaturated, cyclic hydrocarbon forms [e.g., (-)-alpha-pinene, (S)-(-)-limonene, (R)-(+)-limonene, and gamma-terpinene]. Lower levels of inhibition occurred with oxide and alcohol derivatives [(R)-(+)-limonene oxide, alpha-pinene oxide, linalool, alpha-terpineol] and a noncyclic hydrocarbon (beta-myrcene). Isomers of pinene inhibited activity to different extents. Given their natural sources, monoterpenes may be significant factors affecting bacterial activities in nature.

  8. Methanotrophic and Methanogenic Communities in Swiss Alpine Fens Dominated by Carex rostrata and Eriophorum angustifolium.

    PubMed

    Cheema, Simrita; Zeyer, Josef; Henneberger, Ruth

    2015-09-01

    Vascular plants play a key role in controlling CH4 emissions from natural wetlands, because they influence CH4 production, oxidation, and transport to the atmosphere. Here we investigated differences in the abundance and composition of methanotrophic and methanogenic communities in three Swiss alpine fens dominated by different vascular plant species under natural conditions. The sampling locations either were situated at geographically distinct sites with different physicochemical properties but the same dominant plant species (Carex rostrata) or were located within the same site, showing comparable physicochemical pore water properties, but had different plant species (C. rostrata or Eriophorum angustifolium). All three locations were permanently submerged and showed high levels of CH4 emissions (80.3 to 184.4 mg CH4 m(-2) day(-1)). Soil samples were collected from three different depths with different pore water CH4 and O2 concentrations and were analyzed for pmoA and mcrA gene and transcript abundance and community composition, as well as soil structure. The dominant plant species appeared to have a significant influence on the composition of the active methanotrophic communities (transcript level), while the methanogenic communities differed significantly only at the gene level. Yet no plant species-specific microbial taxa were discerned. Moreover, for all communities, differences in composition were more pronounced with the site (i.e., with different physicochemical properties) than with the plant species. Moreover, depth significantly influenced the composition of the active methanotrophic communities. Differences in abundance were generally low, and active methanotrophs and methanogens coexisted at all three locations and depths independently of CH4 and O2 concentrations or plant species.

  9. Characterization of the methanotrophic bacterial community present in a trichloroethylene-contaminated subsurface groundwater site.

    PubMed Central

    Bowman, J P; Jiménez, L; Rosario, I; Hazen, T C; Sayler, G S

    1993-01-01

    Groundwater, contaminated with trichloroethylene (TCE) and tetrachloroethylene (PCE), was collected from 13 monitoring wells at Area M on the U.S. Department of Energy Savannah River Site near Aiken, S.C. Filtered groundwater samples were enriched with methane, leading to the isolation of 25 methanotrophic isolates. The phospholipid fatty acid profiles of all the isolates were dominated by 18:1 omega 8c (60 to 80%), a signature lipid for group II methanotrophs. Subsequent phenotypic testing showed that most of the strains were members of the genus Methylosinus and one isolate was a member of the genus Methylocystis. Most of the methanotroph isolates exhibited soluble methane monooxygenase (sMMO) activity. This was presumptively indicated by the naphthalene oxidation assay and confirmed by hybridization with a gene probe encoding the mmoB gene and by cell extract assays. TCE was degraded at various rates by most of the sMMO-producing isolates, whereas PCE was not degraded. Savannah River Area M and other groundwaters, pristine and polluted, were found to support sMMO activity when supplemented with nutrients and then inoculated with Methylosinus trichosporium OB3b. The maximal sMMO-specific activity obtained in the various groundwaters ranged from 41 to 67% compared with maximal rates obtained in copper-free nitrate mineral salts media. This study partially supports the hypothesis that stimulation of indigenous methanotrophic communities can be efficacious for removal of chlorinated aliphatic hydrocarbons from subsurface sites and that the removal can be mediated by sMMO. PMID:8368829

  10. Methanotrophic and Methanogenic Communities in Swiss Alpine Fens Dominated by Carex rostrata and Eriophorum angustifolium

    PubMed Central

    Cheema, Simrita; Henneberger, Ruth

    2015-01-01

    Vascular plants play a key role in controlling CH4 emissions from natural wetlands, because they influence CH4 production, oxidation, and transport to the atmosphere. Here we investigated differences in the abundance and composition of methanotrophic and methanogenic communities in three Swiss alpine fens dominated by different vascular plant species under natural conditions. The sampling locations either were situated at geographically distinct sites with different physicochemical properties but the same dominant plant species (Carex rostrata) or were located within the same site, showing comparable physicochemical pore water properties, but had different plant species (C. rostrata or Eriophorum angustifolium). All three locations were permanently submerged and showed high levels of CH4 emissions (80.3 to 184.4 mg CH4 m−2 day−1). Soil samples were collected from three different depths with different pore water CH4 and O2 concentrations and were analyzed for pmoA and mcrA gene and transcript abundance and community composition, as well as soil structure. The dominant plant species appeared to have a significant influence on the composition of the active methanotrophic communities (transcript level), while the methanogenic communities differed significantly only at the gene level. Yet no plant species-specific microbial taxa were discerned. Moreover, for all communities, differences in composition were more pronounced with the site (i.e., with different physicochemical properties) than with the plant species. Moreover, depth significantly influenced the composition of the active methanotrophic communities. Differences in abundance were generally low, and active methanotrophs and methanogens coexisted at all three locations and depths independently of CH4 and O2 concentrations or plant species. PMID:26092454

  11. EMERGING TECHNOLOGY BULLETIN - METHANOTROPHIC BIOREACTOR SYSTEM - BIOTROL, INC.

    EPA Science Inventory

    BioTrol's Methanotrophic Bioreactor is an above-ground remedial system for water contaminated with halogenated volatile organic compounds, including trichloroethylene (ICE) and related chemicals. Its design features circumvent problems peculiar to treatment of this unique class o...

  12. Satellite cell activation induced by aerobic muscle adaptation in response to endurance exercise in humans and rodents.

    PubMed

    Abreu, Phablo; Mendes, Sávio Victor Diógenes; Ceccatto, Vânia Marilande; Hirabara, Sandro Massao

    2017-02-01

    Although the requirement of satellite cells activation and expansion following injury, mechanical load or growth stimulus provoked by resistance exercise has been well established, their function in response to aerobic exercise adaptation remains unclear. A clear relationship between satellite cell expansion in fiber-type specific myosin heavy chain and aerobic performance has been related, independent of myonuclear accretion or muscle growth. However, the trigger for this activation process is not fully understood yet and it seems to be a multi-faceted and well-orchestrated process. Emerging in vitro studies suggest a role for metabolic pathways and oxygen availability for satellite cell activation, modulating the self-renewal potential and cell fate control. The goal of this review is to describe and discuss the current knowledge about the satellite cell activation and expansion in response to aerobic exercise adaptation in human and rodent models. Additionally, findings about the in vitro metabolic control, which seems be involved in the satellite cell activation and cell fate control, are presented and discussed.

  13. Locus coeruleus galanin expression is enhanced after exercise in rats selectively bred for high capacity for aerobic activity.

    PubMed

    Murray, Patrick S; Groves, Jessica L; Pettett, Brett J; Britton, Steven L; Koch, Lauren G; Dishman, Rod K; Holmes, Philip V

    2010-12-01

    The neuropeptide galanin extensively coexists with norepinephrine in locus coeruleus (LC) neurons. Previous research in this laboratory has demonstrated that unlimited access to activity wheels in the home cage increases mRNA for galanin (GAL) in the LC, and that GAL mediates some of the beneficial effects of exercise on brain function. To assess whether capacity for aerobic exercise modulates this upregulation in galanin mRNA, three heterogeneous rat models were tested: rats selectively bred for (1) high intrinsic (untrained) aerobic capacity (High Capacity Runners, HCR) and (2) low intrinsic aerobic capacity (Low Capacity Runners, LCR) and (3) unselected Sprague-Dawley (SD) rats with and without free access to running wheels for 3 weeks. Following this exercise protocol, mRNA for tyrosine hydroxylase (TH) and GAL was measured in the LC. The wheel running distances between the three models were significantly different, and age contributed as a significant covariate. Both selection and wheel access condition significantly affected GAL mRNA expression, but not TH mRNA expression. GAL was elevated in exercising HCR and SD rats compared to sedentary rats while LCR rats did not differ between conditions. Overall running distance significantly correlated with GAL mRNA expression, but not with TH mRNA expression. No strain differences in GAL or TH gene expression were observed in sedentary rats. Thus, intrinsic aerobic running capacity influences GAL gene expression in the LC only insofar as actual running behavior is concerned; aerobic capacity does not influence GAL expression in addition to changes associated with running.

  14. Locus coeruleus galanin expression is enhanced after exercise in rats selectively bred for high capacity for aerobic activity

    PubMed Central

    Murray, Patrick S.; Groves, Jessica L.; Pettett, Brett J.; Britton, Steven L.; Koch, Lauren G.; Dishman, Rod K.

    2010-01-01

    The neuropeptide galanin extensively coexists with norepinephrine in locus coeruleus (LC) neurons. Previous research in this laboratory has demonstrated that unlimited access to activity wheels in the home cage increases mRNA for galanin (GAL) in the LC, and that GAL mediates some of the beneficial effects of exercise on brain function. To assess whether capacity for aerobic exercise modulates this upregulation in galanin mRNA, three heterogeneous rat models were tested: rats selectively bred for 1) high intrinsic (untrained) aerobic capacity (High Capacity Runners, HCR) and 2) low intrinsic aerobic capacity (Low Capacity Runners, LCR) and 3) unselected Sprague-Dawley (SD) rats with and without free access to running wheels for three weeks. Following this exercise protocol, mRNA for tyrosine hydroxylase (TH) and GAL was measured in the LC. The wheel-running distances between the three models were significantly different, and age contributed as a significant covariate. Both selection and wheel access condition significantly affected GAL mRNA expression, but not TH mRNA expression. GAL was elevated in exercising HCR and SD rats compared to sedentary rats while LCR rats did not differ between conditions. Overall running distance significantly correlated with GAL mRNA expression, but not with TH mRNA expression. No strain differences in GAL or TH gene expression were observed in sedentary rats. Thus, intrinsic aerobic running capacity influences GAL gene expression in the LC only insofar as actual running behavior is concerned; aerobic capacity does not influence GAL expression in addition to changes associated with running. PMID:20850488

  15. Changes in structure, activity and metabolism of aerobic granules as a microbial response to high phenol loading.

    PubMed

    Jiang, H-L; Tay, J-H; Tay, S T-L

    2004-02-01

    Four column-type sequential aerobic sludge blanket reactors were fed with phenol as the sole carbon and energy source and operated at loading rates of 1.0, 1.5, 2.0 and 2.5 kg phenol m(-3) day(-1). The results indicated that phenol loading exerted a profound influence on the structure, activity and metabolism of the aerobic granules. Compact granules with good settling ability were maintained at loadings up to 2.0 kg phenol m(-3) day(-1), and structurally weakened granules with enhanced production of extracellular polymers and proteins and significantly lower hydrophobicities were observed at the highest loading of 2.5 kg phenol m(-3) day(-1). Specific oxygen uptake rate, catechol 2,3-dioxygenase (C23O) and catechol 1,2-dioxygenase (C12O) activities peaked at a loading of 2.0 kg phenol m(-3) day(-1), and declined thereafter. Granules degraded phenol completely in all four reactors, mainly through the meta cleavage pathway as C23O activities were significantly higher than C12O activities. At the highest loading applied, the anabolism and catabolism of microorganisms were regulated such that phenol degradation proceeded exclusively via the meta pathway, apparently to produce more energy for overstimulation of protein production against phenol toxicity. This work contributes to a better understanding of the ability of aerobic granules to handle high-strength industrial wastewaters containing chemicals that are normally inhibitory to microbial growth.

  16. An Action Research Inquiry into the Relationship Among Aerobic Activities, Memory, and Stress with Students Identified as Gifted

    NASA Astrophysics Data System (ADS)

    Ford, Denise Marie

    Students identified as gifted come from varying socio-economic strata and nationalities with a range of talents and temperaments comprising a diverse community. They may experience stress for a variety of reasons. Although a certain amount of stress can enhance the learning process, too much stress can impede learning, especially memory. Strategies have been offered for relieving stress, yet the benefits of physical activities as stress reducers for the gifted have frequently been overlooked. The purpose of this study was to investigate the relationship among aerobic activity, stress, and memory ability in students in an elementary school gifted program. An exceptional aspect of this research was that the students were an integral part of their own study. As co-researchers they had a vested interest in what they were doing, enhancing the significance of the experience and heightening learning. This action research project conducted in a mid-western school district with fourth and fifth grade students examined the impact of aerobic movement on physical indicators of stress and memory. The study lasted twelve weeks with data collected on physical indicators of stress, memory test scores, parent observations, interviews with students, a parent focus group session, observational data, student comments, and investigator/teacher journal. By infusing regular exercise into curricula, stress levels in students identified as gifted were examined. Students' scores on declarative memory tasks conducted with and without an accompanying aerobic activity were documented. Students learned of the delicate relationship between stress and memory as they studied the physiology of the brain. Twenty-four hour retention rates of declarative memory items were higher when a 20-minute aerobic activity intervention preceded the memory activity. Perceived stress levels were lowered for 14 of the 16 co-researchers. Students indicated a positive attitude toward physical activity and its

  17. The biological effect of metal ions on the granulation of aerobic granular activated sludge.

    PubMed

    Hao, Wen; Li, Yaochen; Lv, Junping; Chen, Lisha; Zhu, Jianrong

    2016-06-01

    As a special biofilm structure, microbial attachment is believed to play an important role in the granulation of aerobic granular activated sludge (AGAS). This experiment was to investigate the biological effect of Ca(2+), Mg(2+), Cu(2+), Fe(2+), Zn(2+), and K(+) which are the most common ions present in biological wastewater treatment systems, on the microbial attachment of AGAS and flocculent activated sludge (FAS), from which AGAS is always derived, in order to provide a new strategy for the rapid cultivation and stability control of AGAS. The result showed that attachment biomass of AGAS was about 300% higher than that of FAS without the addition of metal ions. Different metal ions had different effects on the process of microbial attachment. FAS and AGAS reacted differently to the metal ions as well, and in fact, AGAS was more sensitive to the metal ions. Specifically, Ca(2+), Mg(2+), and K(+) could increase the microbial attachment ability of both AGAS and FAS under appropriate concentrations, Cu(2+), Fe(2+), and Zn(2+) were also beneficial to the microbial attachment of FAS at low concentrations, but Cu(2+), Fe(2+), and Zn(2+) greatly inhibited the attachment process of AGAS even at extremely low concentrations. In addition, the acylated homoserine lactone (AHL)-based quorum sensing system, the content of extracellular polymeric substances and the relative hydrophobicity of the sludges were greatly influenced by metal ions. As all these parameters had close relationships with the microbial attachment process, the microbial attachment may be affected by changes of these parameters.

  18. Physical activity, aerobic fitness, self-perception, and dietary intake in at risk of overweight and normal weight children.

    PubMed

    Ball, Geoff D C; Marshall, J Dru; McCargar, Linda J

    2005-01-01

    Differences in physical activity, aerobic fitness, self-perception, and dietary intake were examined in a sample of six- to ten-year-olds at risk of overweight, and in normal weight boys and girls. Participants (n=20 at risk of overweight [BMI > or =85th percentile]; n=115 normal weight [BMI <85th percentile]; n=68 boys; n=67 girls) had anthropometric, physical activity, aerobic fitness, self-perception, and dietary intake measurements at zero, three, six, and 12 months. Over the 12-month period, normal weight children were more physically active (F=4.1, p<0.05) and aerobically fit (F=14.3, p<0.001), and possessed higher self-perceptions of social acceptance (F=7.3, p<0.01) than their at risk of overweight peers. Fitness differences between the sexes were not apparent at baseline, but emerged over the long term (F=7.9, p<0.01). Overall, boys consumed more total energy, fat, carbohydrate, and protein than did girls, while the entire sample consumed diets low in vegetables and fruits and meat and alternatives, and high in "other" foods. These observations highlight key disparities in lifestyle-related behaviours and perceptions between groups of children according to overweight status and sex. The findings underscore the importance of longitudinal studies in youth because cross-sectional studies may reflect transient differences.

  19. 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

  20. [Methanotrophic bacteria in cold seeps of the floodplains of northern rivers].

    PubMed

    Belova, S É; Oshkin, I Iu; Glagolev, M V; Lapshina, E D; Maksiutov, Sh Sh; Dedysh, S N

    2013-01-01

    Small mud volcanoes (cold seeps), which are common in the floodplains of northern rivers, are a potentially important, although poorly studied sources of atmospheric methane. Field research on the cold seeps of the Mukhrina River (Khanty-Mansiysk Autonomous okrug, Russia) revealed methane fluxes from these structures to be orders of magnitude higher than from equivalent areas of the mid-taiga bogs. Microbial communities developing around the seeps were formed under conditions of high methane concentrations, low temperatures (3-5 degrees C), and near-neutral pH. Molecular identification of methane-oxidizing bacteria from this community by analysis of the pmoA gene encoding particulate methane monooxygenase revealed both type I and type II methanotrophs (classes Gammaproteobacteria and Alphaproteobacteria, respectively), with predomination of type I methanotrophs. Among the latter, microorganisms related to Methylobacterpsychrophilus and Methylobacter tundripaludum, Crenothrix polyspora (a stagnant water dweller), and a number of methanotrophs belonging to unknown taxa were detected. Growth characteristics of two isolates were determined. Methylobactersp. CMS7 exhibited active growth at 4-10 degrees C, while Methylocystis sp. SB12 grew better at 20 degrees C. Experimental results confirmed the major role ofmethanotrophic gammaproteobacteria in controlling the methane emission from cold river seeps.

  1. Molecular characterization of a microbial consortium involved in methane oxidation coupled to denitrification under micro-aerobic conditions

    PubMed Central

    Liu, Jingjing; Sun, Faqian; Wang, Liang; Ju, Xi; Wu, Weixiang; Chen, Yingxu

    2014-01-01

    Methane can be used as an alternative carbon source in biological denitrification because it is nontoxic, widely available and relatively inexpensive. A microbial consortium involved in methane oxidation coupled to denitrification (MOD) was enriched with nitrite and nitrate as electron acceptors under micro-aerobic conditions. The 16S rRNA gene combined with pmoA phylogeny of methanotrophs and nirK phylogeny of denitrifiers were analysed to reveal the dominant microbial populations and functional microorganisms. Real-time quantitative polymerase chain reaction results showed high numbers of methanotrophs and denitrifiers in the enriched consortium. The 16S rRNA gene clone library revealed that Methylococcaceae and Methylophilaceae were the dominant populations in the MOD ecosystem. Phylogenetic analyses of pmoA gene clone libraries indicated that all methanotrophs belonged to Methylococcaceae, a type I methanotroph employing the ribulose monophosphate pathway for methane oxidation. Methylotrophic denitrifiers of the Methylophilaceae that can utilize organic intermediates (i.e. formaldehyde, citrate and acetate) released from the methanotrophs played a vital role in aerobic denitrification. This study is the first report to confirm micro-aerobic denitrification and to make phylogenetic and functional assignments for some members of the microbial assemblages involved in MOD. PMID:24245852

  2. Reverse Methanogenesis and Respiration in Methanotrophic Archaea

    PubMed Central

    Koehorst, Jasper J.; Jetten, Mike S. M.; Stams, Alfons J. M.

    2017-01-01

    Anaerobic oxidation of methane (AOM) is catalyzed by anaerobic methane-oxidizing archaea (ANME) via a reverse and modified methanogenesis pathway. Methanogens can also reverse the methanogenesis pathway to oxidize methane, but only during net methane production (i.e., “trace methane oxidation”). In turn, ANME can produce methane, but only during net methane oxidation (i.e., enzymatic back flux). Net AOM is exergonic when coupled to an external electron acceptor such as sulfate (ANME-1, ANME-2abc, and ANME-3), nitrate (ANME-2d), or metal (oxides). In this review, the reversibility of the methanogenesis pathway and essential differences between ANME and methanogens are described by combining published information with domain based (meta)genome comparison of archaeal methanotrophs and selected archaea. These differences include abundances and special structure of methyl coenzyme M reductase and of multiheme cytochromes and the presence of menaquinones or methanophenazines. ANME-2a and ANME-2d can use electron acceptors other than sulfate or nitrate for AOM, respectively. Environmental studies suggest that ANME-2d are also involved in sulfate-dependent AOM. ANME-1 seem to use a different mechanism for disposal of electrons and possibly are less versatile in electron acceptors use than ANME-2. Future research will shed light on the molecular basis of reversal of the methanogenic pathway and electron transfer in different ANME types. PMID:28154498

  3. 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…

  4. Catalytic epoxidation activity of keplerate polyoxomolybdate nanoball toward aqueous suspension of olefins under mild aerobic conditions.

    PubMed

    Rezaeifard, Abdolreza; Haddad, Reza; Jafarpour, Maasoumeh; Hakimi, Mohammad

    2013-07-10

    Catalytic efficiency of a sphere-shaped nanosized polyoxomolybdate {Mo132} in the aerobic epoxidation of olefins in water at ambient temperature and pressure in the absence of reducing agent is exploited which resulted good-to-high yields and desired selectivity.

  5. Increased aerobic glycolysis is important for the motility of activated VSMC and inhibited by indirubin-3′-monoxime

    PubMed Central

    Heiss, Elke H.; Schachner, Daniel; Donati, Maddalena; Grojer, Christoph S.; Dirsch, Verena M.

    2016-01-01

    Increased aerobic glycolysis is a recognized feature of multiple cellular phenotypes and offers a potential point for drug interference, as pursued by anti-tumor agents targeting the Warburg effect. This study aimed at examining the role of aerobic glycolysis for migration of vascular smooth muscle cells (VSMC) and its susceptibility to the small molecule indirubin-3′-monoxime (I3MO). Activation of VSMC with platelet-derived growth factor (PDGF) resulted in migration and increased glycolytic activity which was accompanied by an increased glucose uptake and hexokinase (HK) 2 expression. Inhibition of glycolysis or hexokinase by pharmacological agents or siRNA-mediated knockdown significantly reduced the migratory behavior in VSMC without affecting cell viability or early actin cytoskeleton rearrangement. I3MO, previously recognized as inhibitor of VSMC migration, was able to counteract the PDGF-activated increase in glycolysis and HK2 abundance. Activation of signal transducer and activator of transcription (STAT) 3 could be identified as crucial event in upregulation of HK2 and glycolytic activity in PDGF-stimulated VSMC and as point of interference for I3MO. I3MO did not inhibit hypoxia-inducible factor (HIF)1α-dependent transcription nor influence miRNA 143 levels, other potential regulators of HK2 levels. Overall, we demonstrate that increased aerobic glycolysis is an important factor for the motility of activated VSMC and that the anti-migratory property of I3MO may partly depend on impairment of glycolysis via a compromised STAT3/HK2 signaling axis. PMID:27185663

  6. Human serum activity of telithromycin, azithromycin and amoxicillin/clavulanate against common aerobic and anaerobic respiratory pathogens.

    PubMed

    Stein, Gary E; Schooley, Sharon; Tyrrell, Kerin L; Citron, Diane M; Goldstein, Ellie J C

    2007-01-01

    Telithromycin is a new ketolide antimicrobial with a good in vitro activity against both aerobic and anaerobic respiratory pathogens. In this study, we evaluated the antibacterial activity over time of telithromycin (800mg), azithromycin (500mg), and amoxicillin/clavulanate (875/125mg) in serum following single oral doses of these agents to 10 healthy subjects. Inhibitory and bactericidal titers were determined at 2, 6, 12, and 24h after each dose and the median titer was used to determine antibacterial activity. Against two azithromycin-resistant strains of Streptococcus pneumoniae, both telithromycin (MIC=0.25 and 0.5 microg/mL) and amoxicillin/clavulanate exhibited inhibitory and cidal activity for at least 6h. All three antibiotics provided prolonged (>or=12h) inhibitory activity against strains of Hemophilus influenzae (telithromycin MIC=4.0 microg/ml). Both telithromycin and amoxicillin/clavulanate exhibited rapid and prolonged inhibitory activity (>or=12h) against each of the anaerobes studied (Finegoldia [Peptostreptococcus] magna Peptostreptococcus micros, Prevotella bivia, and Prevotella melaninogenica). Moreover, both agents provided bactericidal activity against both Prevotella species. In this ex vivo pharmacodynamic study, we found that telithromycin provided rapid and prolonged antibacterial activity in serum against macrolide-resistant strains of S. pneumoniae, beta-lactamase-positive and -negative strains of H. influenzae, and common respiratory anaerobic pathogens. These findings suggest that telithromycin could have clinical utility in the treatment of community-acquired mixed aerobic-anaerobic respiratory tract infections, including chronic sinusitis and aspiration pneumonia.

  7. Between-school variation in physical activity, aerobic fitness, and organized sports participation: a multi-level analysis.

    PubMed

    Kristensen, Peter L; Olesen, Line G; Ried-Larsen, Mathias; Grøntved, Anders; Wedderkopp, Niels; Froberg, Karsten; Andersen, Lars B

    2013-01-01

    A large proportion of a child's day is spent at school interacting with certain physical surroundings, teachers, and school friends. Thus, schools could have a marked impact on establishing physical activity habits. The aim of the present study was to assess between-school variation in physical activity, aerobic fitness, and organized sports participation. Altogether, we tested 1766 nine- and fifteen-year-old children attending 242 school classes at 35 different schools in Denmark in 1997-2003. The intra-class correlation coefficient (ICC) for objectively assessed physical activity ranged between 0.06 and 0.18 depending on the dimension of physical activity and the time considered (i.e. school time vs. leisure time). For aerobic fitness, an ICC of 0.10 was observed, whereas that for organized sports participation ranged between 0.01 and 0.10 depending on the age group. Studying between-school variation in physical activity provides information about the extent to which children adjust their physical activity habits according to the social and environmental circumstances that they share, and helps to plan future school-based physical activity studies, especially in terms of sample size and power calculation.

  8. Activity and growth of anammox biomass on aerobically pre-treated municipal wastewater.

    PubMed

    Laureni, Michele; Weissbrodt, David G; Szivák, Ilona; Robin, Orlane; Nielsen, Jeppe Lund; Morgenroth, Eberhard; Joss, Adriano

    2015-09-01

    Direct treatment of municipal wastewater (MWW) based on anaerobic ammonium oxidizing (anammox) bacteria holds promise to turn the energy balance of wastewater treatment neutral or even positive. Currently, anammox processes are successfully implemented at full scale for the treatment of high-strength wastewaters, whereas the possibility of their mainstream application still needs to be confirmed. In this study, the growth of anammox organisms on aerobically pre-treated municipal wastewater (MWW(pre-treated)), amended with nitrite, was proven in three parallel reactors. The reactors were operated at total N concentrations in the range 5-20 mg(N)∙L(-1), as expected for MWW. Anammox activities up to 465 mg(N)∙L(-1)∙d(-1) were reached at 29 °C, with minimum doubling times of 18 d. Lowering the temperature to 12.5 °C resulted in a marked decrease in activity to 46 mg(N)∙L(-1)∙d(-1) (79 days doubling time), still in a reasonable range for autotrophic nitrogen removal from MWW. During the experiment, the biomass evolved from a suspended growth inoculum to a hybrid system with suspended flocs and wall-attached biofilm. At the same time, MWW(pre-treated) had a direct impact on process performance. Changing the influent from synthetic medium to MWW(pre-treated) resulted in a two-month delay in net anammox growth and a two to three-fold increase in the estimated doubling times of the anammox organisms. Interestingly, anammox remained the primary nitrogen consumption route, and high-throughput 16S rRNA gene-targeted amplicon sequencing analyses revealed that the shift in performance was not associated with a shift in dominant anammox bacteria ("Candidatus Brocadia fulgida"). Furthermore, only limited heterotrophic denitrification was observed in the presence of easily biodegradable organics (acetate, glucose). The observed delays in net anammox growth were thus ascribed to the acclimatization of the initial anammox population or/and the development of a side

  9. Symbioses of methanotrophs and deep-sea mussels (Mytilidae: Bathymodiolinae).

    PubMed

    DeChaine, Eric G; Cavanaugh, Colleen M

    2006-01-01

    The symbioses between invertebrates and chemosynthetic bacteria allow both host and symbiont to colonize and thrive in otherwise inhospitable deep-sea habitats. Given the global distribution of the bathymodioline symbioses, this association is an excellent model for evaluating co-speciation and evolution of symbioses. Thus far, the methanotroph and chemoautotroph endosymbionts of mussels are tightly clustered within two independent clades of gamma Proteobacteria, respectively. Further physiological and genomic studies will elucidate the ecological and evolutionary roles that these bacterial clades play in the symbiosis and chemosynthetic community. Due to the overall abundance of the methanotrophic symbioses at hydrothermal vents and hydrocarbon seeps, they likely play a significant, but as of yet unquantified, role in the biogeochemical cycling of methane. With this in mind, the search for methanotrophic symbioses should not be restricted to these known deep-sea habitats, but rather should be expanded to include methane-rich coastal marine and freshwater environments inhabited by methanotrophs and bivalves. Our current understanding of the bathymodioline symbioses provides a strong foundation for future explorations into the origin, ecology, and evolution of methanotroph symbioses, which are now becoming possible through a combination of classical and advanced molecular techniques.

  10. Investigation of decolorization of textile wastewater in an anaerobic/aerobic biological activated carbon system (A/A BAC).

    PubMed

    Pasukphun, N; Vinitnantharat, S; Gheewala, S

    2010-04-01

    The aim of this study is to investigate the decolorization in anaerobic/aerobic biological activated carbon (A/A BAC) system. The experiment was divided into 2 stages; stage I is batch test for preliminary study of dye removal equilibrium time. The preliminary experiment (stage I) provided the optimal data for experimental design of A/A BAC system in SBR (stage II). Stage II is A/A BAC system imitated Sequencing Batch Reactor (SBR) which consist of 5 main periods; fill, react, settle, draw and idle. React period include anaerobic phase followed by aerobic phase. The BAC main media; Granular Activated Carbon (GAC), Mixed Cultures (MC) and Biological Activated Carbon (BAC) were used for dye and organic substances removal in three different solutions; Desizing Agent Solution (DAS), dye Solution (DS) and Synthetic Textile Wastewater (STW). Results indicate that GAC adsorption plays role in dye removal followed by BAC and MC activities, respectively. In the presence desizing agent, decolorization by MC was improved because desizing agent acts as co-substrates for microorganisms. It was found that 50% of dye removal efficiency was achieved in Fill period by MC. GC/MS analysis was used to identify dye intermediate from decolorization. Dye intermediate containing amine group was found in the solution and on BAC surfaces. The results demonstrated that combination of MC and BAC in the system promotes decolorization and dye intermediate removal. In order to improve dye removal efficiency in an A/A BAC system, replacement of virgin GAC, sufficient co-substrates supply and the appropriate anaerobic: aerobic period should be considered.

  11. Members of the methanotrophic genus Methylomarinum inhabit inland mud pots

    PubMed Central

    Fradet, Danielle T.; Orphan, Victoria J.

    2016-01-01

    Proteobacteria capable of converting the greenhouse gas methane to biomass, energy, and carbon dioxide represent a small but important sink in global methane inventories. Currently, 23 genera of methane oxidizing (methanotrophic) proteobacteria have been described, although many are represented by only a single validly described species. Here we describe a new methanotrophic isolate that shares phenotypic characteristics and phylogenetic relatedness with the marine methanotroph Methylomarinum vadi. However, the new isolate derives from a terrestrial saline mud pot at the northern terminus of the Eastern Pacific Rise (EPR). This new cultivar expands our knowledge of the ecology of Methylomarinum, ultimately towards a fuller understanding of the role of this genus in global methane cycling. PMID:27478692

  12. MAP training: combining meditation and aerobic exercise reduces depression and rumination while enhancing synchronized brain activity.

    PubMed

    Alderman, B L; Olson, R L; Brush, C J; Shors, T J

    2016-02-02

    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.

  13. 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

  14. Warmer and drier conditions and nitrogen fertilizer application altered methanotroph abundance and methane emissions in a vegetable soil.

    PubMed

    Ran, Yu; Xie, Jianli; Xu, Xiaoya; Li, Yong; Liu, Yapeng; Zhang, Qichun; Li, Zheng; Xu, Jianming; Di, Hongjie

    2017-01-01

    Methane (CH4) is a potent greenhouse gas, and soil can both be a source and sink for atmospheric CH4. It is not clear how future climate change may affect soil CH4 emissions and related microbial communities. The aim of this study was to determine the interactive effects of a simulated warmer and drier climate scenarios and the application of different nitrogen (N) sources (urea and manure) on CH4 emissions and related microbial community abundance in a vegetable soil. Greenhouses were used to control simulated climate conditions which gave 2.99 °C warmer and 6.2% lower water content conditions. The field experiment was divided into two phases. At the beginning of phase II, half of the greenhouses were removed to study possible legacy effects of the simulated warmer and drier conditions. The responses in methanogen and methanotroph abundance to a simulated climate change scenario were determined using real-time PCR. The results showed that the simulated warmer and drier conditions in the greenhouses significantly decreased CH4 emissions largely due to the lower soil moisture content. For the same reason, CH4 emissions of treatments in phase I were much lower than the same treatments in phase II. The abundance of methanotrophs showed a more significant response than methanogens to the simulated climate change scenario, increasing under simulated drier conditions. Methanogenic community abundance remained low, except where manure was applied which provided a source of organic C that stimulated methanogen growth. Soil moisture content was a major driver for methanotroph abundance and strongly affected CH4 emissions. The application of N source decreased CH4 emissions probably because of increased methanotrophic activity. CH4 emissions were positively correlated to methanogenic abundance and negatively correlated to methanotrophic abundance. These results demonstrate that projected future climate change conditions can have a feedback impact on CH4 emissions from the

  15. Chemical composition, cytotoxic and antimicrobial activity of essential oils from Cassia bakeriana Craib. against aerobic and anaerobic oral pathogens.

    PubMed

    Cunha, Luís C S; de Morais, Sérgio A L; Martins, Carlos H G; Martins, Mário M; Chang, Roberto; de Aquino, Francisco J T; de Oliveira, Alberto; Moraes, Thaís da S; Machado, Fabrício C; da Silva, Cláudio V; do Nascimento, Evandro A

    2013-04-18

    The chemical composition of the essential oils from leaves, bark and wood of Cassia bakeriana Craib. was determined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Alcohols, aldehydes and fatty acids were the major components in leaf and bark oil, while wood essential oil was rich in fatty acids. Terpenes such as linalool, (E)-nerolidol and phytol were present in low concentrations. The antimicrobial activity against aerobic and anaerobic oral bacteria was evaluated using the microdilution method, as was the cell viability test carried out with Vero cells. The oils from leaves and bark showed high antimicrobial activity, with minimum inhibitory concentrations between 62.5 and 125 µg·mL⁻¹ for most of the tested bacteria, including Streptococcus mutans, the main etiological agent of dental caries. Leaves oil displayed the lowest cytotoxic effect (EC₅₀ of 153 µg·mL⁻¹), while wood oil exhibited the highest toxicity to Vero cells. C. bakeriana oils are thus a source of biologically active compounds against aerobic and anaerobic oral microorganisms. This study is the first report on the chemical composition, antimicrobial activity and cytotoxicity of C. bakeriana.

  16. 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

  17. Effectiveness of Active Packaging on Control of Escherichia Coli O157:H7 and Total Aerobic Bacteria on Iceberg Lettuce.

    PubMed

    Lu, Haixia; Zhu, Junli; Li, Jianrong; Chen, Jinru

    2015-06-01

    Contaminated leafy green vegetables have been linked to several outbreaks of human gastrointestinal infections. Antimicrobial interventions that are adoptable by the fresh produce industry for control of pathogen contamination are in great demand. This study was undertaken to evaluate the efficacy of sustained active packaging on control of Escherichia coli O157:H7 and total aerobic bacteria on lettuce. Commercial Iceberg lettuce was inoculated with a 3-strain mixture of E. coli O157:H7 at 10(2) or 10(4) CFU/g. The contaminated lettuce and un-inoculated controls were placed respectively in 5 different active packaging structures. Traditional, nonactive packaging structure was included as controls. Packaged lettuce was stored at 4, 10, or 22 °C for 3 wk and sampled weekly for the population of E. coli O157:H7 and total aerobic bacteria. Results showed that packaging structures with ClO2 generator, CO2 generator, or one of the O2 scavengers effectively controlled the growth of E. coli O157:H7 and total aerobic bacteria under all storage conditions. Packaging structure with the ClO2 generator was most effective and no E. coli O157:H7 was detected in samples packaged in this structure except for those that were inoculated with 4 log CFU/g of E. coli O157:H7 and stored at 22 °C. Packaging structures with an oxygen scavenger and the allyl isothiocyanate generator were mostly ineffective in control of the growth of the bacteria on Iceberg lettuce. The research suggests that some of the packaging structures evaluated in the study can be used to control the presence of foodborne pathogens on leafy green vegetables.

  18. Methylocapsa palsarum sp. nov., a methanotroph isolated from a subArctic discontinuous permafrost ecosystem.

    PubMed

    Dedysh, Svetlana N; Didriksen, Alena; Danilova, Olga V; Belova, Svetlana E; Liebner, Susanne; Svenning, Mette M

    2015-10-01

    An aerobic methanotrophic bacterium was isolated from a collapsed palsa soil in northern Norway and designated strain NE2T. Cells of this strain were Gram-stain-negative, non-motile, non-pigmented, slightly curved thick rods that multiplied by normal cell division. The cells possessed a particulate methane monooxygenase enzyme (pMMO) and utilized methane and methanol. Strain NE2T grew in a wide pH range of 4.1–8.0 (optimum pH 5.2–6.5) at temperatures between 6 and 32 °C (optimum 18–25 °C), and was capable of atmospheric nitrogen fixation under reduced oxygen tension. The major cellular fatty acids were C18 : 1ω7c, C16 : 0 and C16 : 1ω7c, and the DNA G+C content was 61.7 mol%. The isolate belonged to the family Beijerinckiaceae of the class Alphaproteobacteria and was most closely related to the facultative methanotroph Methylocapsa aurea KYGT (98.3 % 16S rRNA gene sequence similarity and 84 % PmoA sequence identity). However, strain NE2T differed from Methylocapsa aurea KYGT by cell morphology, the absence of pigmentation, inability to grow on acetate, broader pH growth range, and higher tolerance to NaCl. Therefore, strain NE2T represents a novel species of the genus Methylocapsa, for which we propose the name Methylocapsa palsarum sp. nov. The type strain is NE2T ( = LMG 28715T = VKM B-2945T).

  19. Surface-active ionic liquids in catalysis: Impact of structure and concentration on the aerobic oxidation of octanol in water.

    PubMed

    Cognigni, Alice; Kampichler, Sebastian; Bica, Katharina

    2017-04-15

    We present design and synthesis of surface-active ionic liquids for the application in micellar catalysis. A series of 1-methyl-3-dodecylimidazolium based ionic liquids with variable core structures including dicationic and zwitterionic ones was synthesized and characterized. These surface-active ionic liquids where applied in the aerobic oxidation of aliphatic alcohols to carbonyl compounds. A strong dependence on the ionic liquid concentration and structure was identified, which is in accordance with the concepts of micellar catalysis. Optimum conditions for the oxidation of 1-octanol could be identified, and the use of surface-active ionic liquids strongly improved the reaction performance compared to pure water. Under optimized conditions, it was possible to isolate up to 75% of octanoic acid using only small amounts of surface-active ionic liquid in a 0.05mM solution in water without further ligands.

  20. The effects of acute aerobic activity on cognition and cross-domain transfer to eating behavior.

    PubMed

    Lowe, Cassandra J; Hall, Peter A; Vincent, Corita M; Luu, Kimberley

    2014-01-01

    Prior studies have demonstrated that a single session of aerobic exercise can enhance cognitive functioning; specifically, the inhibition facet of executive function (EF). Additionally, previous research has demonstrated that inhibitory abilities are essential for effective dietary self-control. However, it is currently unknown whether exercise induced enhancements in EF also facilitate self-control in the dietary domain. The present study sought to determine whether a single session of aerobic exercise enhances EF, and whether there is a transfer effect to dietary self-control. Thirty four undergraduate students were randomly assigned to one of three exercise conditions: (1) minimal exercise; (2) moderate intensity exercise (30% heart rate reserve); (3) vigorous intensity exercise (50% heart rate reserve). After the exercise bout, participants completed three standardized EF tasks followed by a bogus taste test for three appetitive snack foods (milk chocolate and potato chips) and two control foods (dark chocolate and crackers). The amount of food consumed during the taste test was covertly measured. The results revealed a significant main effect of treatment condition on the Stroop task performance, but not Go-NoGo (GNG) and Stop Signal task performance. Findings with respect to food consumption revealed that EF moderated the treatment effect, such that those with larger exercise effects on Stroop performance in the moderate intensity exercise condition consumed more control foods (but not less appetitive foods). These findings support the contention that a single bout of aerobic exercise enhances EF, and may have transfer effects to the dietary domain, but that such effects may be indirect in nature.

  1. Seasonal and spatial aspects of the eco-distribution of methanotrophic bacteria in floodplain soils

    NASA Astrophysics Data System (ADS)

    Bodelier, P. L. E.; Meima-Franke, M.; Kamst, M.; Bodrossy, L.; Stralis-Pavese, N.; Hefting, M. M.; Laanbroek, R.

    2009-04-01

    METHECO is the acronym of a consortium of research groups funded by the European Science foundation (ESF) within the EuroDIVERSITY program. The consortium investigates the role of microbial diversity in the dynamics and stability of global methane consumption. The consortium covers various habitats (i.e. Landfills, rice paddies, alpine meadows, littoral wetlands, forests, arctic wetlands, peat soils and river floodplains) and assesses the effects of natural environmental perturbation on the function structure relationship of methane-consuming microbial communities. Consortium members follow the same experimental and methodological scheme using DNA and RNA based techniques (i.e. pmoA-based cloning, DGGE, micro arrays, Real Time PCR, stable isotope probing). This paper presents the results obtained in a river floodplain along the river Rhine in the Netherlands, a habitat anticipated to be subjected to major changes in flooding regime due to climate change. Experiments were carried out to assess methanotrophic diversity, methane oxidation kinetics and spatial variability of function and structure of methane-oxidizing communities. Flooding events affected methane consumption negatively on short term. However, the long -term consequences of the flooding regime where the establishment of a distinct maximum methane consumption activity exactly in the part of the floodplain intermediate between permanently and irregularly flooded, where moisture and organic matter content were optimal for methane cycling. The methanotrophic community composition as analysed by pmoA micro array mirrored the result of the activity measurements, demonstrating that the communities differed clearly according to the flooding gradient. Diversity as assessed by micro array and activity components (initial consumption, Vmax, Vmax/Km) were positively correlated. QPCR analyses showed that main types of methanotrophic bacteria were differentially distributed throughout the flooding gradient. Type I

  2. Radioassay for Hydrogenase Activity in Viable Cells and Documentation of Aerobic Hydrogen-Consuming Bacteria Living in Extreme Environments

    PubMed Central

    Schink, Bernhard; Lupton, F. S.; Zeikus, J. G.

    1983-01-01

    An isotopic tracer assay based on the hydrogenase-dependent formation of tritiated water from tritium gas was developed for in life analysis of microbial hydrogen transformation. This method allowed detection of bacterial hydrogen metabolism in pure cultures or in natural samples obtained from aquatic ecosystems. A differentiation between chemical-biological and aerobic-anaerobic hydrogen metabolism was established by variation of the experimental incubation temperature or by addition of selective inhibitors. Hydrogenase activity was shown to be proportional to the consumption or production of hydrogen by cultures of Desulfovibrio vulgaris, Clostridium pasteurianum, and Methanosarcina barkeri. This method was applied, in connection with measurements of free hydrogen and most-probable-number enumerations, in aerobic natural source waters to establish the activity and document the ecology of hydrogen-consuming bacteria in extreme acid, thermal, or saline environments. The utility of the assay is based in part on the ability to quantify bacterial hydrogen transformation at natural hydrogen partial pressures, without the use of artificial electron acceptors. PMID:16346288

  3. Effect of thiamine pyrophosphate on levels of serum lactate, maximum oxygen consumption and heart rate in athletes performing aerobic activity.

    PubMed

    Bautista-Hernández, V M; López-Ascencio, R; Del Toro-Equihua, M; Vásquez, C

    2008-01-01

    The aim of this study was to determine the effect of thiamine pyrophosphate (TPP) on serum lactate levels, maximum oxygen consumption (Vo(2max)) and heart rate in male athletes performing aerobic activity. A double-blind, randomized, crossover study was performed in which lactate levels, Vo(2max) and heart rates in 27 male athletes were compared at rest and after exercise, following administration of placebo (sodium chloride 0.9%) or TPP (1 mg/kg). At rest, serum lactate levels after placebo or TPP were similar; however, after exercise, the levels were lower in the athletes after taking TPP than after placebo. During exercise, Vo(2max) in athletes on TPP was higher than on placebo. At rest, heart rate after taking placebo or TPP was similar but, after exercise, heart rate was lower after taking TPP than after placebo. It is concluded that TPP caused serum lactate levels and heart rate to be lower than placebo and Vo(2max) to be higher in athletes performing aerobic physical activity.

  4. The Transition from Aerobic to Anaerobic Metabolism.

    ERIC Educational Resources Information Center

    Skinner, James S.; McLellan, Thomas H.

    1980-01-01

    The transition from aerobic to anaerobic metabolism is discussed. More research is needed on different kinds of athletes and athletic activities and how they may affect aerobic and anaerobic metabolisms. (CJ)

  5. Skin microvascular reactivity in children and adolescents with type 1 diabetes in relation to levels of physical activity and aerobic fitness.

    PubMed

    Roche, Denise M; Edmunds, Sarah; Cable, Tim; Didi, Mo; Stratton, Gareth

    2008-11-01

    No studies to date have evaluated the relationship between exercise and microvascular function in youth with type 1 diabetes mellitus (T1DM). Twenty-nine complication free children and adolescents with T1DM were assessed for skin microvascular reactivity, aerobic fitness (VO2peak) and physical activity. VO2peak but not physical activity was significantly and independently associated with maximal hyperemia of the skin microcirculation (p < .01). No significant associations were found between venoarteriolar reflex (VAR) vasoconstriction and VO2peak or physical activity. Aerobic fitness may be an important indicator or mediator of effective microvascular endothelial function in youth with T1DM.

  6. 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.

  7. Exercise, Animal Aerobics, and Interpretation?

    ERIC Educational Resources Information Center

    Oliver, Valerie

    1996-01-01

    Describes an aerobic activity set to music for children that mimics animal movements. Example exercises include walking like a penguin or jumping like a cricket. Stresses basic aerobic principles and designing the program at the level of children's motor skills. Benefits include reaching people who normally don't visit nature centers, and bridging…

  8. Extensions to modeling aerobic carbon degradation using combined respirometric-titrimetric measurements in view of activated sludge model calibration.

    PubMed

    Sin, Gürkan; Vanrolleghem, Peter A

    2007-08-01

    Recently a model was introduced to interpret the respirometric (OUR) -titrimetric (Hp) data obtained from aerobic oxidation of different carbon sources in view of calibration of Activated Sludge Model No.1 (ASM1). The model requires, among others, the carbon dioxide transfer rate (CTR) to be relatively constant during aerobic experiments. As CTR is an inherently nonlinear process, this assumption may not hold for certain experimental conditions. Hence, we extended the model to describe the nonlinear CTR behavior. A simple calibration procedure of the CO2 model was developed only using titrimetric data. The identifiable parameter subset of this model when using titrimetric data only contained the first equilibrium constant of the CO2 dissociation, pK1, the initial aqueous CO2 concentration, C(Tinit) and the nitrogen content of biomass, i(NBM). The extended model was then successfully applied to interpret typical data obtained from respirometric-titrimetric measurements with a nonlinear CO2 stripping process. The parameter estimation results using titrimetric data were consistent with the results estimated using respirometric data (OUR) alone or combined OUR and Hp data, thereby supporting the validity of the dynamic CO2 model and its calibration approach. The increased range of applicability and accurate utilization of the titrimetric data are expected to contribute particularly to the improvement of calibration of ASM models using batch experiments.

  9. Methane dynamics in an alpine fen: a field-based study on methanogenic and methanotrophic microbial communities.

    PubMed

    Franchini, Alessandro G; Henneberger, Ruth; Aeppli, Meret; Zeyer, Josef

    2015-03-01

    Wetlands are important sources of the greenhouse gas methane (CH4). We provide an in situ study of CH4 dynamics in the permanently submerged soil of a Swiss alpine fen. Physico-chemical pore water analyses were combined with structural and microbiological analyses of soil cores at high vertical resolution down to 50 cm depth. Methanotrophs and methanogens were active throughout the depth profile, and highest abundance of active methanotrophs and methanogens [6.1 × 10(5) and 1.1 × 10(7) pmoA and mcrA transcripts (g soil)(-1), respectively] was detected in the uppermost 2 cm of the soil. Active methanotrophic communities in the near-surface zone, dominated by viable mosses, varied from the communities in the deeper zones, but further changes with depth were not pronounced. Apart from a distinct active methanogenic community in the uppermost sample, a decrease of acetoclastic Methanosaetaceae with depth was observed in concomitance with decreasing root surface area. Overall, root surface area correlated with mcrA transcript abundance and CH4 pore water concentrations, which peaked (137.1 μM) at 10 to 15 cm depth. Our results suggest that stimulation of methanogenesis by root exudates of vascular plants had a stronger influence on CH4 dynamics than stimulation of CH4 oxidation by O2 input.

  10. Transcriptomic evidence for net methane oxidation and net methane production in putative ANaerobic MEthanotrophic (ANME) archaea

    NASA Astrophysics Data System (ADS)

    Lloyd, K. G.; Alperin, M. J.; Teske, A.

    2010-12-01

    Anaerobic methane oxidation regulates methane emissions in marine sediments and is thought to be mediated by uncultured methanogen-like archaea collectively labeled ANME (for ANaerobic MEthanotrophs). ANME archaea are often assumed to be obligate methanotrophs that are incapable of net methanogenesis, and are therefore used as proxies for anaerobic methane oxidation in many environments in spite of uncertainty regarding their metabolic capabilities. We tested this assumption by detecting and quantifying methanogenic gene transcription of ANME archaea across clearly differentiated zones of methane oxidation vs. methane production in sediments from the White Oak River estuary, NC. ANME-1 archaea (a group of putative obligate methanotrophs) consistently transcribe 16S rRNA and mRNA of methyl coenzyme M reductase (mcrA) the key gene for methanogenesis, up to 45 cm into methanogenic sediments. CARD-FISH shows that ANME-1 archaea exist as single rod-shaped cells or pairs of cells, and in very low numbers. Integrating normalized depth-distributions of 16S rDNA and rRNA (measured with qPCR and RT-qPCR, respectively) shows that 26-77 % of the rDNA proxy for ANME-1 cell numbers, and 18-74 % of the rRNA proxy for ANME-1 activity occurs within methane-producing sediments. mRNA transcripts of dissimilatory sulfite reductase (dsrAB) from sulfate reducing bacteria, the putative syntrophic partners of sulfate-dependent methane oxidation, were amplified consistently from methane-oxidizing sediments, and inconsistently from methane-producing sediments. These results change the perspective from ANME-1 archaea as obligate methane oxidizers to methanogens that are also capable of methane oxidation.

  11. Aerobic exercise plus weight loss improves insulin sensitivity and increases skeletal muscle glycogen synthase activity in older men.

    PubMed

    Ryan, Alice S; Katzel, Leslie I; Prior, Steven J; McLenithan, John C; Goldberg, Andrew P; Ortmeyer, Heidi K

    2014-07-01

    The purpose of this study was to determine the effects of 6-month aerobic exercise training + weight loss (AEX + WL) on basal and insulin activation of glycogen synthase, basal citrate synthase activity, and Akt and AS160 phosphorylation in older, overweight/obese insulin-resistant men (n = 14; 63 ± 2 years; body mass index, 32 ± kg/m(2)). Muscle samples of the vastus lateralis were collected before and during a 3-hour 80 mU/m(2)/min hyperinsulinemic-euglycemic clamp. AEX + WL increased VO2max by 11% (p < .05) and decreased body weight (-9%, p < .001). AEX + WL increased basal citrate synthase activity by 46% (p < .01) and insulin activation of independent (2.9-fold) and fractional (2.3-fold) activities (both p < .001) of glycogen synthase. AEX + WL had no effect on phosphorylation of Akt or AS160. Glucose utilization (M) improved 25% (p < .01), and the change tended to be related to the increase in insulin activation of glycogen synthase fractional activity (r = .50, p = .08) following AEX + WL. In summary, AEX + WL has a robust effect on insulin activation of skeletal muscle glycogen synthase activity that likely contributes to improved glucose utilization in older insulin-resistant men.

  12. Aerobic Exercise Plus Weight Loss Improves Insulin Sensitivity and Increases Skeletal Muscle Glycogen Synthase Activity in Older Men

    PubMed Central

    Katzel, Leslie I.; Prior, Steven J.; McLenithan, John C.; Goldberg, Andrew P.; Ortmeyer, Heidi K.

    2014-01-01

    The purpose of this study was to determine the effects of 6-month aerobic exercise training + weight loss (AEX + WL) on basal and insulin activation of glycogen synthase, basal citrate synthase activity, and Akt and AS160 phosphorylation in older, overweight/obese insulin-resistant men (n = 14; 63 ± 2 years; body mass index, 32 ± kg/m2). Muscle samples of the vastus lateralis were collected before and during a 3-hour 80 mU/m2/min hyperinsulinemic-euglycemic clamp. AEX + WL increased VO2max by 11% (p < .05) and decreased body weight (−9%, p < .001). AEX + WL increased basal citrate synthase activity by 46% (p < .01) and insulin activation of independent (2.9-fold) and fractional (2.3-fold) activities (both p < .001) of glycogen synthase. AEX + WL had no effect on phosphorylation of Akt or AS160. Glucose utilization (M) improved 25% (p < .01), and the change tended to be related to the increase in insulin activation of glycogen synthase fractional activity (r = .50, p = .08) following AEX + WL. In summary, AEX + WL has a robust effect on insulin activation of skeletal muscle glycogen synthase activity that likely contributes to improved glucose utilization in older insulin-resistant men. PMID:24357038

  13. Litter type affects the activity of aerobic decomposers in a boreal peatland more than site nutrient and water table regimes

    NASA Astrophysics Data System (ADS)

    Straková, P.; Niemi, R. M.; Freeman, C.; Peltoniemi, K.; Toberman, H.; Heiskanen, I.; Fritze, H.; Laiho, R.

    2011-09-01

    Peatlands are carbon (C) storage ecosystems sustained by a high water table (WT). High WT creates anoxic conditions that suppress the activity of aerobic decomposers and provide conditions for peat accumulation. Peatland function can be dramatically affected by WT drawdown caused by climate and/or land-use change. Aerobic decomposers are directly affected by WT drawdown through environmental factors such as increased oxygenation and nutrient availability. Additionally, they are indirectly affected via changes in plant community composition and litter quality. We studied the relative importance of direct and indirect effects of WT drawdown on aerobic decomposer activity in plant litter at two stages of decomposition (incubated in the field for 1 or 2 years). We did this by profiling 11 extracellular enzymes involved in the mineralization of organic C, nitrogen (N), phosphorus (P) and sulphur. Our study sites represented a three-stage chronosequence from pristine to short-term (years) and long-term (decades) WT drawdown conditions under two nutrient regimes (bog and fen). The litter types included reflected the prevalent vegetation: Sphagnum mosses, graminoids, shrubs and trees. Litter type was the main factor shaping microbial activity patterns and explained about 30 % of the variation in enzyme activities and activity allocation. Overall, enzyme activities were higher in vascular plant litters compared to Sphagnum litters, and the allocation of enzyme activities towards C or nutrient acquisition was related to the initial litter quality (chemical composition). Direct effects of WT regime, site nutrient regime and litter decomposition stage (length of incubation period) summed to only about 40 % of the litter type effect. WT regime alone explained about 5 % of the variation in enzyme activities and activity allocation. Generally, enzyme activity increased following the long-term WT drawdown and the activity allocation turned from P and N acquisition towards C

  14. Nitrite- and Nitrate-Dependent Methanotrophs - Environmental Detection and Relevance in Freshwater Ecosystems

    NASA Astrophysics Data System (ADS)

    Ettwig, K. F.

    2014-12-01

    Humans continue to have an enormous impact on global C and N cycles. While a clear stimulation of methane emissions through human activities is evident, the role of also increasingly released nitrogenous compounds as electron acceptors for microbial methane oxidation is not well constrained. We have developed diverse methods for environmental detection of nitrate(NO3-)- and - predominantly - nitrite(NO2-)-dependent methanotrophs, which have been applied to several freshwater environments. In contrast to most metabolically flexible heterotrophic denitrifiers, the microorganisms responsible for methane-dependent nitrate/nitrite reduction seem to be specialized to use methane only, grow slowly and employ pathways different from each other and from model organisms, which necessitate new approaches for the assessment of their environmental relevance. Nitrite-dependent methane oxidation is carried out by bacteria of the NC10 phylum, whereas nitrate-dependent methane oxidizers are close relatives of methanogenic archaea and sulfate-dependent anaerobic methanotrophs (ANME-2). Laboratory enrichment cultures of the nitrite-reducing methanotroph Methylomirabilis oxyfera (NC10 phylum) have formed the basis for its genetic and physiological characterization and the development of several independent methods for its sensitive detection. M. oxyfera differs from all known microorganisms by encoding an incomplete denitrification pathway, in which the last 2 steps, the reduction of NO via N2O to N2, apparently is replaced by the dismutation of NO to N2 and O2. The intracellularly produced O2 is used for methane oxidation via a methane monooxygenase, analogously to the phylogenetically unrelated proteobacterial methanotrophs. But unlike in proteobacteria, C is not assimilated from methane, but rather CO2, with important consequences for the interpretation of environmental isotope labelling studies. In addition, M. oxyfera is characterized by a distinct PLFA profile, including

  15. The influence of hydrolysis induced biopolymers from recycled aerobic sludge on specific methanogenic activity and sludge filterability in an anaerobic membrane bioreactor.

    PubMed

    Buntner, D; Spanjers, H; van Lier, J B

    2014-03-15

    The objective of the present study was to evaluate the impact of excess aerobic sludge on the specific methanogenic activity (SMA), in order to establish the maximum allowable aerobic sludge loading. In batch tests, different ratios of aerobic sludge to anaerobic inoculum were used, i.e. 0.03, 0.05, 0.10 and 0.15, showing that low ratios led to an increased SMA. However, the ratio 0.15 caused more than 20% SMA decrease. In addition to the SMA tests, the potential influence of biopolymers and extracellular substances, that are generated as a result of excess aerobic sludge hydrolysis, on membrane performance was determined by assessing the fouling potential of the liquid broth, taking into account parameters such as specific resistance to filtration (SRF) and supernatant filterability (SF). Addition of aerobic sludge to the anaerobic biomass resulted in a high membrane fouling potential. The increase in biopolymers could be ascribed to aerobic sludge hydrolysis. A clear positive correlation between the concentration of the colloidal fraction of biopolymer clusters (cBPC) and the SRF was observed and a negative correlation between the cBPC and the SF measured at the end of the above described SMA tests. The latter implies that sludge filtration resistance increases when more aerobic sludge is hydrolyzed, and thus more cBPC is released. During AnMBR operation, proteins significantly contributed to sludge filterability decrease expressed as SRF and SF, whereas the carbohydrate fraction of SMP was of less importance due to low concentrations. On the contrary, carbohydrates seemed to improve filterability and diminish SRF of the sludge. Albeit, cBPC increase caused an increase in mean TMP during the AnMBR operation, confirming that cBPC is positively correlated to membrane fouling.

  16. Arthritis and Aerobic Exercise: A Review.

    ERIC Educational Resources Information Center

    Ike, Robert W.; And Others

    1989-01-01

    Arthritic patients who regularly do aerobic exercise make significant gains in aerobic and functional status, and in subjective areas like pain tolerance and mood. Still, they are often advised to curtail physical activity. Guidelines are presented for physicians prescribing aerobic exercise. An exercise tolerance test is recommended. (SM)

  17. Characterization of odor emission from alternating aerobic and anoxic activated sludge systems using real-time total reduced sulfur analyzer.

    PubMed

    Kim, Hyunook; Lee, Hyunjoo; Choi, Eunsun; Choi, Il; Shin, Taesub; Im, Hyungjoon; Ahn, Soobin

    2014-12-01

    Anaerobic biodegradation of sulfur-containing compounds always generates volatile sulfur compounds (VSCs) including H2S, methyl mercaptan, and dimethyl sulfide (DMS). VSC emissions from wastewater treatment plants (WWTPs) result in odor complaints from people living nearby. To control odor-causing compounds in WWTPs, it is important to know the odor emission quantity particularly with continuous monitoring. Since modified activated sludge processes always include anaerobic, anoxic and aerobic conditions for nutrient removal, odor emission from these different environmental settings is expected. In this study, continuous monitoring of VSCs from the headspace of an alternating aerobic and anoxic (AAA) activated sludge process via total reduced sulfur (TRS) analyzer was performed. There is clear pattern of the initial TRS peak immediately after the initiation of the aeration in the AAA system and TRS concentration begins to drop through the remaining air-on cycle. On the other hand, during the air-off period, TRS concentrations increase with time. In particular, a clear inflection point in the TRS profile could be observed after complete removal of nitrate during air-off, meaning more VSCs formation. Since the highest odor emission occurs after the initiation of aeration, the future control of exhausted air should only deal with air collected during the initial aeration period (e.g., 30min), a similar concept for the treatment of first flush in combined sewer overflow. In addition, application of a control scheme to initiate aeration immediately after denitrification is completed during air-off should be beneficial in reducing odor emission.

  18. Aerobic capacity correlates to self-assessed physical function but not to overall disease activity or organ damage in women with systemic lupus erythematosus with low-to-moderate disease activity and organ damage.

    PubMed

    Boström, C; Dupré, B; Tengvar, P; Jansson, E; Opava, C H; Lundberg, I E

    2008-02-01

    The present aim is to investigate the relationships between aerobic capacity and disease activity, organ damage, health-related quality of life (HRQL) and physical activity in 34 women with systemic lupus erythematosus (SLE) with low-to-moderate disease activity and organ damage. Mean age was 51 (SD 10) years, disease duration 17 (SD 11) years. Aerobic capacity (maximal oxygen uptake/VO2 max) was measured with a bicycle ergometer exercise test. Overall disease activity was assessed with Systemic Lupus Activity Measure (SLAM) and the modified Systemic Lupus Erythematosus-Disease Activity Index (modified SLE-DAI), overall organ damage with the Systemic Lupus International Collaboration Clinics/American College of Rheumatology-Damage Index, [SLICC/(ACR)-DI], HRQL with the 36-item Short-form health-survey (SF-36) and physical activity with a self-assessed question. The women who were low-to-moderately physically active had 89-92% (P < or = 0.001) of VO2 max predicted for sedentary women. Maximal oxygen uptake (L/min, mL/min/kg) correlated to SF-36 physical function (rs = 0.49, rs = 0.72) (P < or = 0.01), but not (rs < or = 0.25) to other HRQL scales, overall disease activity or organ damage or physical activity. The correlation between aerobic capacity and physical function and the absence of correlation between aerobic capacity and physical activity, suggest a possible disease-related factor behind the low aerobic capacity. However, with no correlation between aerobic capacity and overall disease activity and organ damage, low physical activity may contribute to the low aerobic capacity in our sample.

  19. Comparative in vitro activities of azithromycin, Bay y 3118, levofloxacin, sparfloxacin, and 11 other oral antimicrobial agents against 194 aerobic and anaerobic bite wound isolates.

    PubMed Central

    Goldstein, E J; Nesbit, C A; Citron, D M

    1995-01-01

    The activities of sparfloxacin, levofloxacin, Bay y 3118, azithromycin, cefprozil, loracarbef, and nine other oral antimicrobial agents against 194 aerobic and anaerobic clinical bite wound isolates were determined by the agar dilution method. Sparfloxacin, levofloxacin, and Bay y 3118 were active against all aerobic isolates (MICs at which 90% of the isolates are inhibited [MIC90], < or = 1.0 microgram/ml for sparfloxacin and levofloxacin and 0.1 microgram/ml for Bay y 3118) and many anaerobic isolates, with the exception of the fusobacteria. Azithromycin was more active than erythromycin by 1 to 2 dilutions against many aerobes, including Pasteurella multocida and Eikenella corrodens, and by 2 to 4 dilutions against anaerobic isolates. Cefprozil was more active (MIC90, < or = 1 microgram/ml) than loracarbef (MIC90, < or = 4 micrograms/ml) against aerobic gram-positive isolates, but both had poor activity (MIC90, > or = 16 micrograms/ml) against peptostreptococci. Both cefprozil and loracarbef had MIC90s of < or = 0.5 micrograms/ml against P. multocida. PMID:7625795

  20. Cognitively Engaging Chronic Physical Activity, But Not Aerobic Exercise, Affects Executive Functions in Primary School Children: A Group-Randomized Controlled Trial.

    PubMed

    Schmidt, Mirko; Jäger, Katja; Egger, Fabienne; Roebers, Claudia M; Conzelmann, Achim

    2015-12-01

    Although the positive effects of different kinds of physical activity (PA) on cognitive functioning have already been demonstrated in a variety of studies, the role of cognitive engagement in promoting children's executive functions is still unclear. The aim of the current study was therefore to investigate the effects of two qualitatively different chronic PA interventions on executive functions in primary school children. Children (N = 181) aged between 10 and 12 years were assigned to either a 6-week physical education program with a high level of physical exertion and high cognitive engagement (team games), a physical education program with high physical exertion but low cognitive engagement (aerobic exercise), or to a physical education program with both low physical exertion and low cognitive engagement (control condition). Executive functions (updating, inhibition, shifting) and aerobic fitness (multistage 20-m shuttle run test) were measured before and after the respective condition. Results revealed that both interventions (team games and aerobic exercise) have a positive impact on children's aerobic fitness (4-5% increase in estimated VO2max). Importantly, an improvement in shifting performance was found only in the team games and not in the aerobic exercise or control condition. Thus, the inclusion of cognitive engagement in PA seems to be the most promising type of chronic intervention to enhance executive functions in children, providing further evidence for the importance of the qualitative aspects of PA.

  1. Aerobic Capacity, Physical Activity and Metabolic Risk Factors in Firefighters Compared with Police Officers and Sedentary Clerks

    PubMed Central

    Leischik, Roman; Foshag, Peter; Strauß, Markus; Littwitz, Henning; Garg, Pankaj; Dworrak, Birgit; Horlitz, Marc

    2015-01-01

    Background This study examined the association between the physical work environment and physiological performance measures, physical activity levels and metabolic parameters among German civil servants. A main focus in this study was to examine the group differences rather than measuring the absolute values in an occupational group. Methods We prospectively examined 198 male German civil servants (97 firefighters [FFs], 55 police officers [POs] and 46 sedentary clerks [SCs]). For each parameter, the groups were compared using a linear regression adjusted for age. Results The 97 FFs showed a similar maximal aerobic power (VO2max l/min) of 3.17±0.44 l/min compared with the POs, who had a maximal aerobic power of 3.13±0.62 l/min (estimated difference, POs vs. FFs: 0.05, CI: -0.12-0.23, p=0.553). The maximal aerobic power of the FFs was slightly higher than that of the SCs, who had a maximal aerobic power of 2.85±0.52 l/min (-0.21, CI: -0.39-0.04, p=0.018 vs. FFs). The average physical activity (in metabolic equivalents [METS]/week) of the FFs was 3818.8±2843.5, whereas those of the POs and SCs were 2838.2±2871.9 (-808.2, CI: 1757.6-141.2, p=0.095) and 2212.2±2292.8 (vs. FFs: -1417.1, CI: -2302-531.88, p=0.002; vs. POs: -2974.4, CI: -1611.2-393.5, p=0.232), respectively. For the FFs, the average body fat percentage was 17.7%±6.2, whereas it was 21.4%±5.6 for the POs (vs. FFs: 2.75, CI: 0.92-4.59, p=0.004) and 20.8%±6.5 for the SCs (vs. FFs: 1.98, CI: -0.28-4.25, p=0.086; vs. POs: -0.77, CI: 3.15-1.61, p=0.523). The average waist circumference was 89.8 cm±10.0 for the FFs, 97.8 cm±12.4 (5.63, CI: 2.10-9.15, p=0.002) for the POs, and 97.3±11.7 (vs. FFs: -4.89, CI: 1.24-8.55, p=0.009; vs. POs: -0.73, CI: -5.21-3.74, p=0.747) for the SCs. Conclusions The FFs showed significantly higher physical activity levels compared with the SCs. The PO group had the highest cardiovascular risk of all of the groups because it included more participants with metabolic

  2. Brain activation, affect, and aerobic exercise: an examination of both state-independent and state-dependent relationships.

    PubMed

    Petruzzello, S J; Tate, A K

    1997-09-01

    Resting electroencephalograph (EEG) asymmetry is a biological marker of the propensity to respond affectively to, and a measure of change in affect associated with, acute aerobic exercise. This study examined the EEG-affect-exercise relationship. Twenty participants performed each of three randomly assigned 30-min conditions: (a) a nonexercise control, (b) a cycling exercise at 55% VO2max, and (c) a cycling exercise at 70% VO2max. EEG and affect were assessed pre- and 0, 5, 10, 20, and 30 min postcondition. No significant results were seen in the control or 55% conditions. In the 70% exercise condition, greater relative left frontal activation preexercise predicted increased positive affect and reduced state anxiety postexercise. Participants (n = 7) with extreme relative left frontal activation postexercise reported concomitant decreases in anxiety, whereas participants (n = 7) with extreme relative right frontal activation postexercise reported increases in anxiety. These findings (a) replicate prior work, (b) suggest a dose-response intensity effect, and (c) support the idea that exercise is an emotion-eliciting event. Affective responses seem to be mediated in part by differential resting levels of activation in the anterior brain regions. Ongoing anterior brain activation reflected concurrent postexercise affect.

  3. Genomic Reconstruction of an Uncultured Hydrothermal Vent Gammaproteobacterial Methanotroph (Family Methylothermaceae) Indicates Multiple Adaptations to Oxygen Limitation

    PubMed Central

    Skennerton, Connor T.; Ward, Lewis M.; Michel, Alice; Metcalfe, Kyle; Valiente, Chanel; Mullin, Sean; Chan, Ken Y.; Gradinaru, Viviana; Orphan, Victoria J.

    2015-01-01

    Hydrothermal vents are an important contributor to marine biogeochemistry, producing large volumes of reduced fluids, gasses, and metals and housing unique, productive microbial and animal communities fueled by chemosynthesis. Methane is a common constituent of hydrothermal vent fluid and is frequently consumed at vent sites by methanotrophic bacteria that serve to control escape of this greenhouse gas into the atmosphere. Despite their ecological and geochemical importance, little is known about the ecophysiology of uncultured hydrothermal vent-associated methanotrophic bacteria. Using metagenomic binning techniques, we recovered and analyzed a near-complete genome from a novel gammaproteobacterial methanotroph (B42) associated with a white smoker chimney in the Southern Lau basin. B42 was the dominant methanotroph in the community, at ∼80x coverage, with only four others detected in the metagenome, all on low coverage contigs (7x–12x). Phylogenetic placement of B42 showed it is a member of the Methylothermaceae, a family currently represented by only one sequenced genome. Metabolic inferences based on the presence of known pathways in the genome showed that B42 possesses a branched respiratory chain with A- and B-family heme copper oxidases, cytochrome bd oxidase and a partial denitrification pathway. These genes could allow B42 to respire over a wide range of oxygen concentrations within the highly dynamic vent environment. Phylogenies of the denitrification genes revealed they are the result of separate horizontal gene transfer from other Proteobacteria and suggest that denitrification is a selective advantage in conditions where extremely low oxygen concentrations require all oxygen to be used for methane activation. PMID:26779119

  4. Genomic Reconstruction of an Uncultured Hydrothermal Vent Gammaproteobacterial Methanotroph (Family Methylothermaceae) Indicates Multiple Adaptations to Oxygen Limitation.

    PubMed

    Skennerton, Connor T; Ward, Lewis M; Michel, Alice; Metcalfe, Kyle; Valiente, Chanel; Mullin, Sean; Chan, Ken Y; Gradinaru, Viviana; Orphan, Victoria J

    2015-01-01

    Hydrothermal vents are an important contributor to marine biogeochemistry, producing large volumes of reduced fluids, gasses, and metals and housing unique, productive microbial and animal communities fueled by chemosynthesis. Methane is a common constituent of hydrothermal vent fluid and is frequently consumed at vent sites by methanotrophic bacteria that serve to control escape of this greenhouse gas into the atmosphere. Despite their ecological and geochemical importance, little is known about the ecophysiology of uncultured hydrothermal vent-associated methanotrophic bacteria. Using metagenomic binning techniques, we recovered and analyzed a near-complete genome from a novel gammaproteobacterial methanotroph (B42) associated with a white smoker chimney in the Southern Lau basin. B42 was the dominant methanotroph in the community, at ∼80x coverage, with only four others detected in the metagenome, all on low coverage contigs (7x-12x). Phylogenetic placement of B42 showed it is a member of the Methylothermaceae, a family currently represented by only one sequenced genome. Metabolic inferences based on the presence of known pathways in the genome showed that B42 possesses a branched respiratory chain with A- and B-family heme copper oxidases, cytochrome bd oxidase and a partial denitrification pathway. These genes could allow B42 to respire over a wide range of oxygen concentrations within the highly dynamic vent environment. Phylogenies of the denitrification genes revealed they are the result of separate horizontal gene transfer from other Proteobacteria and suggest that denitrification is a selective advantage in conditions where extremely low oxygen concentrations require all oxygen to be used for methane activation.

  5. Feasibility of atmospheric methane removal using methanotrophic biotrickling filters.

    PubMed

    Yoon, Sukhwan; Carey, Jeffrey N; Semrau, Jeremy D

    2009-07-01

    Methane is a potent greenhouse gas with a global warming potential ~23 times that of carbon dioxide. Here, we describe the modeling of a biotrickling filtration system composed of methane-consuming bacteria, i.e., methanotrophs, to assess the utility of these systems in removing methane from the atmosphere. Model results indicate that assuming the global average atmospheric concentration of methane, 1.7 ppmv, methane removal is ineffective using these methanotrophic biofilters as the methane concentration is too low to enable cell survival. If the concentration is increased to 500-6,000 ppmv, however, similar to that found above landfills and in concentrated animal feeding operations (factory farms), 4.98-35.7 tons of methane can be removed per biofilter per year assuming biotrickling filters of typical size (3.66 m in diameter and 11.5 m in height). Using reported ranges of capital, operational, and maintenance costs, the cost of the equivalent ton of CO(2) removal using these systems is $90-$910 ($2,070-$20,900 per ton of methane), depending on the influent concentration of methane and if heating is required. The use of methanotrophic biofilters for controlling methane emissions is technically feasible and, provided that either the costs of biofilter construction and operation are reduced or the value of CO(2) credits is increased, can also be economically attractive.

  6. Biological Methanol Production by a Type II Methanotroph Methylocystis bryophila.

    PubMed

    Patel, Sanjay K S; Mardina, Primata; Kim, Sang-Yong; Lee, Jung-Kul; Kim, In-Won

    2016-04-28

    Methane (CH₄) is the most abundant component in natural gas. To reduce its harmful environmental effect as a greenhouse gas, CH₄ can be utilized as a low-cost feed for the synthesis of methanol by methanotrophs. In this study, several methanotrophs were examined for their ability to produce methanol from CH₄; including Methylocella silvestris, Methylocystis bryophila, Methyloferula stellata, and Methylomonas methanica. Among these methanotrophs, M. bryophila exhibited the highest methanol production. The optimum process parameters aided in significant enhancement of methanol production up to 4.63 mM. Maximum methanol production was observed at pH 6.8, 30°C, 175 rpm, 100 mM phosphate buffer, 50 mM MgCl₂ as a methanol dehydrogenase inhibitor, 50% CH₄ concentration, 24 h of incubation, and 9 mg of dry cell mass ml(-1) inoculum load, respectively. Optimization of the process parameters, screening of methanol dehydrogenase inhibitors, and supplementation with formate resulted in significant improvements in methanol production using M. bryophila. This report suggests, for the first time, the potential of using M. bryophila for industrial methanol production from CH₄.

  7. Diversity of cultivated and metabolically active aerobic anoxygenic phototrophic bacteria along an oligotrophic gradient in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Jeanthon, C.; Boeuf, D.; Dahan, O.; Le Gall, F.; Garczarek, L.; Bendif, E. M.; Lehours, A.-C.

    2011-07-01

    Aerobic anoxygenic phototrophic (AAP) bacteria play significant roles in the bacterioplankton productivity and biogeochemical cycles of the surface ocean. In this study, we applied both cultivation and mRNA-based molecular methods to explore the diversity of AAP bacteria along an oligotrophic gradient in the Mediterranean Sea in early summer 2008. Colony-forming units obtained on three different agar media were screened for the production of bacteriochlorophyll-a (BChl-a), the light-harvesting pigment of AAP bacteria. BChl-a-containing colonies represented a low part of the cultivable fraction. In total, 54 AAP strains were isolated and the phylogenetic analyses based on their 16S rRNA and pufM genes showed that they were all affiliated to the Alphaproteobacteria. The most frequently isolated strains belonged to Citromicrobium bathyomarinum, and Erythrobacter and Roseovarius species. Most other isolates were related to species not reported to produce BChl-a and/or may represent novel taxa. Direct extraction of RNA from seawater samples enabled the analysis of the expression of pufM, the gene coding for the M subunit of the reaction centre complex of aerobic anoxygenic photosynthesis. Clone libraries of pufM gene transcripts revealed that most phylotypes were highly similar to sequences previously recovered from the Mediterranean Sea and a large majority (~94 %) was affiliated to the Gammaproteobacteria. The most abundantly detected phylotypes occurred in the western and eastern Mediterranean basins. However, some were exclusively detected in the eastern basin, reflecting the highest diversity of pufM transcripts observed in this ultra-oligotrophic region. To our knowledge, this is the first study to document extensively the diversity of AAP isolates and to unveil the active AAP community in an oligotrophic marine environment. By pointing out the discrepancies between culture-based and molecular methods, this study highlights the existing gaps in the understanding

  8. Diversity of cultivated and metabolically active aerobic anoxygenic phototrophic bacteria along an oligotrophic gradient in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Jeanthon, C.; Boeuf, D.; Dahan, O.; Le Gall, F.; Garczarek, L.; Bendif, E. M.; Lehours, A.-C.

    2011-05-01

    Aerobic anoxygenic phototrophic (AAP) bacteria play significant roles in the bacterioplankton productivity and biogeochemical cycles of the surface ocean. In this study, we applied both cultivation and mRNA-based molecular methods to explore the diversity of AAP bacteria along an oligotrophic gradient in the Mediterranean Sea in early summer 2008. Colony-forming units obtained on three different agar media were screened for the production of bacteriochlorophyll-a (BChl-a), the light-harvesting pigment of AAP bacteria. BChl-a-containing colonies represented a low part of the cultivable fraction. In total, 52 AAP strains were isolated and the phylogenetic analyses based on their 16S rRNA and pufM genes showed that they were all affiliated to the Alphaproteobacteria. The most frequently isolated strains belonged to Citromicrobium bathyomarinum, and Erythrobacter and Roseovarius species. Most other isolates were related to species not reported to produce BChl-a and/or may represent novel taxa. Direct extraction of RNA from seawater samples enabled the analysis of the expression of pufM, the gene coding for the M subunit of the reaction centre complex of aerobic anoxygenic photosynthesis. Clone libraries of pufM gene transcripts revealed that most phylotypes were highly similar to sequences previously recovered from the Mediterranean Sea and a large majority (~94%) was affiliated with the Gammaproteobacteria. The most abundantly detected phylotypes occurred in the western and eastern Mediterranean basins. However, some were exclusively detected in the eastern basin, reflecting the highest diversity of pufM transcripts observed in this ultra-oligotrophic region. To our knowledge, this is the first study to document extensively the diversity of AAP isolates and to unveil the active AAP community in an oligotrophic marine environment. By pointing out the discrepancies between culture-based and molecular methods, this study highlights the existing gaps in the understanding

  9. Metaproteomic identification of diazotrophic methanotrophs and their localization in root tissues of field-grown rice plants.

    PubMed

    Bao, Zhihua; Okubo, Takashi; Kubota, Kengo; Kasahara, Yasuhiro; Tsurumaru, Hirohito; Anda, Mizue; Ikeda, Seishi; Minamisawa, Kiwamu

    2014-08-01

    In a previous study by our group, CH4 oxidation and N2 fixation were simultaneously activated in the roots of wild-type rice plants in a paddy field with no N input; both processes are likely controlled by a rice gene for microbial symbiosis. The present study examined which microorganisms in rice roots were responsible for CH4 oxidation and N2 fixation under the field conditions. Metaproteomic analysis of root-associated bacteria from field-grown rice (Oryza sativa Nipponbare) revealed that nitrogenase complex-containing nitrogenase reductase (NifH) and the alpha subunit (NifD) and beta subunit (NifK) of dinitrogenase were mainly derived from type II methanotrophic bacteria of the family Methylocystaceae, including Methylosinus spp. Minor nitrogenase proteins such as Methylocella, Bradyrhizobium, Rhodopseudomonas, and Anaeromyxobacter were also detected. Methane monooxygenase proteins (PmoCBA and MmoXYZCBG) were detected in the same bacterial group of the Methylocystaceae. Because these results indicated that Methylocystaceae members mediate both CH4 oxidation and N2 fixation, we examined their localization in rice tissues by using catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). The methanotrophs were localized around the epidermal cells and vascular cylinder in the root tissues of the field-grown rice plants. Our metaproteomics and CARD-FISH results suggest that CH4 oxidation and N2 fixation are performed mainly by type II methanotrophs of the Methylocystaceae, including Methylosinus spp., inhabiting the vascular bundles and epidermal cells of rice roots.

  10. Preparation and Catalytic Activity for Aerobic Glucose Oxidation of Crown Jewel Structured Pt/Au Bimetallic Nanoclusters.

    PubMed

    Zhang, Haijun; Wang, Liqiong; Lu, Lilin; Toshima, Naoki

    2016-08-01

    Understanding of the "structure-activity" relations for catalysts at an atomic level has been regarded as one of the most important objectives in catalysis studies. Bimetallic nanoclusters (NCs) in its many types, such as core/shell, random alloy, cluster-in-cluster, bi-hemisphere, and crown jewel (one kind of atom locating at the top position of another kind of NC), attract significant attention owing to their excellent optical, electronic, and catalytic properties. PVP-protected crown jewel-structured Pt/Au (CJ-Pt/Au) bimetallic nanoclusters (BNCs) with Au atoms located at active top sites were synthesized via a replacement reaction using 1.4-nm Pt NCs as mother clusters even considering the fact that the replacement reaction between Pt and Au(3+) ions is difficult to be occurred. The prepared CJ-Pt/Au colloidal catalysts characterized by UV-Vis, TEM, HR-TEM and HAADF-STEM-EELS showed a high catalytic activity for aerobic glucose oxidation, and the top Au atoms decorating the Pt NCs were about 15 times more active than the Au atoms of Au NCs with similar particle size.

  11. Effects of a single bout of lower-body aerobic exercise on muscle activation and performance during subsequent lower- and upper-body resistance exercise workouts.

    PubMed

    Tan, Jeremy G; Coburn, Jared W; Brown, Lee E; Judelson, Daniel A

    2014-05-01

    A single bout of lower-body aerobic exercise may negatively affect a subsequent lower-body resistance exercise workout. However, less is known regarding the effects of a lower-body aerobic workout on muscle activation and performance during a subsequent upper-body resistance exercise workout. Therefore, the purpose of this study was to compare muscle activation and performance during lower- and upper-body resistance exercise workouts after a single bout of lower-body aerobic exercise on an elliptical machine. Fourteen men (mean age = 24.1 ± 2.3 years, height = 180.8 ± 6.9 cm, body mass = 91.9 ± 16.4 kg) completed 4 trials in random order. Two trials consisted of 30 minutes on the elliptical machine, using the lower body only, at 70% of age-predicted maximum heart rate before either a back squat or bench press workout, consisting of 3 sets to failure performed at 75% 1 repetition maximum. The other 2 trials consisted of only the back squat or bench press resistance workouts. To quantify muscle activation, bipolar surface electromyography electrodes were placed on the rectus femoris and vastus lateralis or pectoralis major. Acute lower-body aerobic exercise on an elliptical machine significantly reduced the number of repetitions completed for the back squat but not the bench press exercise. There was no significant difference in muscle activation between the elliptical and no elliptical conditions. However, for both exercises and conditions, muscle activation increased significantly between the first and final repetitions for the first 2 sets but not for the third set. These results suggest that to optimize the quality of a lower-body resistance-training workout, the workout should not be preceded by lower-body aerobic exercise.

  12. Preparation and Catalytic Activity for Aerobic Glucose Oxidation of Crown Jewel Structured Pt/Au Bimetallic Nanoclusters

    PubMed Central

    Zhang, Haijun; Wang, Liqiong; Lu, Lilin; Toshima, Naoki

    2016-01-01

    Understanding of the “structure-activity” relations for catalysts at an atomic level has been regarded as one of the most important objectives in catalysis studies. Bimetallic nanoclusters (NCs) in its many types, such as core/shell, random alloy, cluster-in-cluster, bi-hemisphere, and crown jewel (one kind of atom locating at the top position of another kind of NC), attract significant attention owing to their excellent optical, electronic, and catalytic properties. PVP-protected crown jewel-structured Pt/Au (CJ-Pt/Au) bimetallic nanoclusters (BNCs) with Au atoms located at active top sites were synthesized via a replacement reaction using 1.4-nm Pt NCs as mother clusters even considering the fact that the replacement reaction between Pt and Au3+ ions is difficult to be occurred. The prepared CJ-Pt/Au colloidal catalysts characterized by UV-Vis, TEM, HR-TEM and HAADF-STEM-EELS showed a high catalytic activity for aerobic glucose oxidation, and the top Au atoms decorating the Pt NCs were about 15 times more active than the Au atoms of Au NCs with similar particle size. PMID:27476577

  13. Postprandial improvement in insulin sensitivity after a single exercise session in adolescents with low aerobic fitness and physical activity.

    PubMed

    Short, Kevin R; Pratt, Lauren V; Teague, April M; Man, Chiara Dalla; Cobelli, Claudio

    2013-03-01

    The purpose of this study was to determine the acute and residual impact of a single exercise bout on meal glucose control in adolescents with habitually low physical activity. Twelve adolescents (seven females/five males, 14 ± 2 yr) completed three trials. One trial [No Exercise (No Ex)] was completed after refraining from vigorous activity for ≥ 3 d. On the other two trials, a 45-min aerobic exercise bout at 75% peak heart rate was performed either 17-h Prior Day Exercise (Prior Day Ex) trial or 1-h Same Day Exercise (Same Day Ex) trial before consuming the test meal (2803 kJ, 45/40/15% energy as carbohydrate/fat/protein, respectively). Compared to No Ex, insulin sensitivity (SI) (minimal model analysis) was increased by 45% (p < 0.03) and 78% (p < 0.01) on the Prior Day Ex and Same Day Ex trials, respectively. This improvement in glucose control was supported by corresponding reductions in the net area under the curve for glucose, insulin, and c-peptide, although there was no change in postprandial suppression of fatty acids. These results show that SI is improved with a single bout of moderate intensity exercise in adolescents with habitually low physical activity and that the residual beneficial effect of exercise lasts at least 17 h. This finding highlights the plasticity of exercise responses in youth and the importance of daily exercise for metabolic health.

  14. Inhibition of boric acid and sodium borate on the biological activity of microorganisms in an aerobic biofilter.

    PubMed

    Güneş, Y

    2013-01-01

    The aim of this work was to study the inhibition effect of boric acid and sodium borate on the treatment of boron containing synthetic wastewater by a down flow aerobic fixed bed biofilm reactor at various chemical oxygen demand (COD)/boron ratios (0.47-20.54). The inhibitory effect of boron on activated sludge was evaluated on the basis of COD removal during the experimental period. The biofilter (effective volume = 2.5 L) was filled with a ring of plastic material inoculated with acclimated activated sludge. The synthetic wastewater composed of glucose, urea, KH2PO4, MgSO4, Fe2 SO4, ZnSO4 x 7H20, KCl, CaCl2, and di-sodium tetraborate decahydrate or boric acid (B = 100-2000 mg L(-1)). The biological treatment of boron containing wastewater resulted in a low treatment removal rate due to the reduced microbial activity as a result of toxic effects of high boron concentrations. The decrease in the COD removal rate by the presence of either boric acid or sodium borate was practically indistinguishable. It was observed from the experiments that about 90-95% of COD removal was possible at high COD/boron ratios.

  15. Preparation and Catalytic Activity for Aerobic Glucose Oxidation of Crown Jewel Structured Pt/Au Bimetallic Nanoclusters

    NASA Astrophysics Data System (ADS)

    Zhang, Haijun; Wang, Liqiong; Lu, Lilin; Toshima, Naoki

    2016-08-01

    Understanding of the “structure-activity” relations for catalysts at an atomic level has been regarded as one of the most important objectives in catalysis studies. Bimetallic nanoclusters (NCs) in its many types, such as core/shell, random alloy, cluster-in-cluster, bi-hemisphere, and crown jewel (one kind of atom locating at the top position of another kind of NC), attract significant attention owing to their excellent optical, electronic, and catalytic properties. PVP-protected crown jewel-structured Pt/Au (CJ-Pt/Au) bimetallic nanoclusters (BNCs) with Au atoms located at active top sites were synthesized via a replacement reaction using 1.4-nm Pt NCs as mother clusters even considering the fact that the replacement reaction between Pt and Au3+ ions is difficult to be occurred. The prepared CJ-Pt/Au colloidal catalysts characterized by UV-Vis, TEM, HR-TEM and HAADF-STEM-EELS showed a high catalytic activity for aerobic glucose oxidation, and the top Au atoms decorating the Pt NCs were about 15 times more active than the Au atoms of Au NCs with similar particle size.

  16. Autophagic Signaling and Proteolytic Enzyme Activity in Cardiac and Skeletal Muscle of Spontaneously Hypertensive Rats following Chronic Aerobic Exercise

    PubMed Central

    McMillan, Elliott M.; Paré, Marie-France; Baechler, Brittany L.; Graham, Drew A.; Rush, James W. E.; Quadrilatero, Joe

    2015-01-01

    Hypertension is a cardiovascular disease associated with deleterious effects in skeletal and cardiac muscle. Autophagy is a degradative process essential to muscle health. Acute exercise can alter autophagic signaling. Therefore, we aimed to characterize the effects of chronic endurance exercise on autophagy in skeletal and cardiac muscle of normotensive and hypertensive rats. Male Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR) were assigned to a sedentary condition or 6 weeks of treadmill running. White gastrocnemius (WG) of hypertensive rats had higher (p<0.05) caspase-3 and proteasome activity, as well as elevated calpain activity. In addition, skeletal muscle of hypertensive animals had elevated (p<0.05) ATG7 and LC3I protein, LAMP2 mRNA, and cathepsin activity, indicative of enhanced autophagic signaling. Interestingly, chronic exercise training increased (p<0.05) Beclin-1, LC3, and p62 mRNA as well as proteasome activity, but reduced (p<0.05) Beclin-1 and ATG7 protein, as well as decreased (p<0.05) caspase-3, calpain, and cathepsin activity. Left ventricle (LV) of hypertensive rats had reduced (p<0.05) AMPKα and LC3II protein, as well as elevated (p<0.05) p-AKT, p-p70S6K, LC3I and p62 protein, which collectively suggest reduced autophagic signaling. Exercise training had little effect on autophagy-related signaling factors in LV; however, exercise training increased (p<0.05) proteasome activity but reduced (p<0.05) caspase-3 and calpain activity. Our results suggest that autophagic signaling is altered in skeletal and cardiac muscle of hypertensive animals. Regular aerobic exercise can effectively alter the proteolytic environment in both cardiac and skeletal muscle, as well as influence several autophagy-related factors in skeletal muscle of normotensive and hypertensive rats. PMID:25799101

  17. Autophagic signaling and proteolytic enzyme activity in cardiac and skeletal muscle of spontaneously hypertensive rats following chronic aerobic exercise.

    PubMed

    McMillan, Elliott M; Paré, Marie-France; Baechler, Brittany L; Graham, Drew A; Rush, James W E; Quadrilatero, Joe

    2015-01-01

    Hypertension is a cardiovascular disease associated with deleterious effects in skeletal and cardiac muscle. Autophagy is a degradative process essential to muscle health. Acute exercise can alter autophagic signaling. Therefore, we aimed to characterize the effects of chronic endurance exercise on autophagy in skeletal and cardiac muscle of normotensive and hypertensive rats. Male Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR) were assigned to a sedentary condition or 6 weeks of treadmill running. White gastrocnemius (WG) of hypertensive rats had higher (p<0.05) caspase-3 and proteasome activity, as well as elevated calpain activity. In addition, skeletal muscle of hypertensive animals had elevated (p<0.05) ATG7 and LC3I protein, LAMP2 mRNA, and cathepsin activity, indicative of enhanced autophagic signaling. Interestingly, chronic exercise training increased (p<0.05) Beclin-1, LC3, and p62 mRNA as well as proteasome activity, but reduced (p<0.05) Beclin-1 and ATG7 protein, as well as decreased (p<0.05) caspase-3, calpain, and cathepsin activity. Left ventricle (LV) of hypertensive rats had reduced (p<0.05) AMPKα and LC3II protein, as well as elevated (p<0.05) p-AKT, p-p70S6K, LC3I and p62 protein, which collectively suggest reduced autophagic signaling. Exercise training had little effect on autophagy-related signaling factors in LV; however, exercise training increased (p<0.05) proteasome activity but reduced (p<0.05) caspase-3 and calpain activity. Our results suggest that autophagic signaling is altered in skeletal and cardiac muscle of hypertensive animals. Regular aerobic exercise can effectively alter the proteolytic environment in both cardiac and skeletal muscle, as well as influence several autophagy-related factors in skeletal muscle of normotensive and hypertensive rats.

  18. The interrelationship between muscle oxygenation, muscle activation, and pulmonary oxygen uptake to incremental ramp exercise: influence of aerobic fitness.

    PubMed

    Boone, Jan; Barstow, Thomas J; Celie, Bert; Prieur, Fabrice; Bourgois, Jan

    2016-01-01

    We investigated whether muscle and ventilatory responses to incremental ramp exercise would be influenced by aerobic fitness status by means of a cross-sectional study with a large subject population. Sixty-four male students (age: 21.2 ± 3.2 years) with a heterogeneous peak oxygen uptake (51.9 ± 6.3 mL·min(-1)·kg(-1), range 39.7-66.2 mL·min(-1)·kg(-1)) performed an incremental ramp cycle test (20-35 W·min(-1)) to exhaustion. Breath-by-breath gas exchange was recorded, and muscle activation and oxygenation were measured with surface electromyography and near-infrared spectroscopy, respectively. The integrated electromyography (iEMG), mean power frequency (MPF), deoxygenated [hemoglobin and myoglobin] (deoxy[Hb+Mb]), and total[Hb+Mb] responses were set out as functions of work rate and fitted with a double linear function. The respiratory compensation point (RCP) was compared and correlated with the breakpoints (BPs) (as percentage of peak oxygen uptake) in muscle activation and oxygenation. The BP in total[Hb+Mb] (83.2% ± 3.0% peak oxygen uptake) preceded (P < 0.001) the BP in iEMG (86.7% ± 4.0% peak oxygen uptake) and MPF (86.3% ± 4.1% peak oxygen uptake), which in turn preceded (P < 0.01) the BP in deoxy[Hb+Mb] (88.2% ± 4.5% peak oxygen uptake) and RCP (87.4% ± 4.5% peak oxygen uptake). Furthermore, the peak oxygen uptake was significantly (P < 0.001) positively correlated to the BPs and RCP, indicating that the BPs in total[Hb+Mb] (r = 0.66; P < 0.001), deoxy[Hb+Mb] (r = 0.76; P < 0.001), iEMG (r = 0.61; P < 0.001), MPF (r = 0.63; P < 0.001), and RCP (r = 0.75; P < 0.001) occurred at a higher percentage of peak oxygen uptake in subjects with a higher peak oxygen uptake. In this study a close relationship between muscle oxygenation, activation, and pulmonary oxygen uptake was found, occurring in a cascade of events. In subjects with a higher aerobic fitness level this cascade occurred at a higher relative intensity.

  19. The Relation between Aerobic Fitness, Muscular Fitness, and Obesity in Children from Three Countries at Different Stages of the Physical Activity Transition

    PubMed Central

    Héroux, M.; Onywera, V.; Tremblay, M. S.; Adamo, K. B.; Lopez Taylor, J.; Jáuregui Ulloa, E.; Janssen, I.

    2013-01-01

    Background. The physical activity transition is contributing to an increase in childhood obesity and a decrease in fitness worldwide. This study compared body composition and fitness measures in children from three countries and examined intercountry differences in the relationship between these variables. Methods. Participants consisted of 736 Canadian, 193 Mexican, and 179 Kenyan children aged 9–13 years. Body mass index (BMI), waist circumference, triceps skinfolds, aerobic fitness, and muscular fitness were measured. Linear regression was used to examine associations between variables. Results. The prevalence of obesity was the highest in Mexican children (9.2% boys, 8.4% girls) and the lowest in Kenyan children (0.9% boys, 2.8% girls). Aerobic fitness (VO2max in mL/kg/min) was the highest in Kenyan children (50.2 boys, 46.7 girls) and the lowest in Canadian children (41.3 boys, 38.3 girls). Aerobic fitness was negatively associated with body composition measures irrespective of country and sex. Mexican children with low aerobic fitness had higher body composition measures than Canadian and Kenyan children. Muscular fitness was not associated with the body composition measures in Kenyan children but was a weak positive correlate of BMI and waist circumference in Canadian and Mexican children. Conclusion. The current study provides some evidence to support the physical activity transition hypothesis. PMID:24533216

  20. A comparative adsorption study: 17β-estradiol onto aerobic granular sludge and activated sludge.

    PubMed

    Zheng, Xiao-ying; He, Yu-jie; Chen, Wei; Wang, Ming-yang; Cao, Su-lan; Ni, Ming; Chen, Yu

    2016-01-01

    Adsorption plays a significant role in removing hydrophobic 17β-estradiol (E2) from wastewater. Batch experiments were conducted to compare the adsorption of E2 onto activated aerobic granular sludge (AGS) and activated sludge (AS), and features evaluated included the adsorption kinetics, thermodynamics, and influence of other environmental factors. By using a non-chemical wet-heat technique, both AGS and AS were treated to inactivated status. Then, after loading E2, the adsorption equilibrium capacity of the AGS was found to be greater than that of the AS at the same initial concentration of E2. Moreover, both the adsorption processes corresponded to a pseudo-second-order kinetic model; the adsorption rate constant of AGS was found to be higher and the half-adsorption time was shorter than that of AS. Next, evaluations of adsorption isotherms and thermodynamics indicated that the adsorption process was mainly a physical process. Lower temperatures facilitated a higher equilibrium adsorption capacity. However, the adsorption binding sites of AGS were distributed more uniformly at higher temperature, in contrast to the distribution found for AS. Finally, acidic conditions and an appropriate ionic strength (0.4 mol/L) were found to be particularly conducive to the adsorption process. Overall, the results showed that AGS has the potential to adsorb E2 with significant efficiency, thereby offering a new and more efficient means of treating E2 and trace oestrogens in wastewater.

  1. Modeling a bench-scale alternating aerobic/anoxic activated sludge system for nitrogen removal using a modified ASM1.

    PubMed

    Kim, Hyunook; Noh, Soohong; Colosimo, Mark

    2009-07-01

    The Activated Sludge Model No. 1 (ASM1), developed by The International Association of Water Pollution Research and Control, was applied to model dynamics of NH4+, and NO3- in a bench scale alternating aerobic-anoxic (AAA) activated sludge system for nitrogen removal. The model was modified by eliminating inert soluble COD (S(I)) and inert particulate COD (X(I)) from the model's state variables as these two variables are not involved in any biological reaction and are not readily measurable with conventional routine COD analysis. It was assumed that the soluble COD and particulate COD of wastewater represent readily biodegradable COD (S(S)) and slowly biodegradable (X(S)) in the model, respectively. In addition, alkalinity was also removed from the model, since alkalinity of an AAA system remains stable due to the cyclic modes of the system. Even with the elimination of the three state variables and the assumption made, the model could reasonably predict the NH4+ and NO3- dynamics of the AAA system, and effluent NH4+ and NO3- concentrations with adjustment of only a few kinetic parameters. Compared to the original ASM1, it is expected that the modified ASM1 presented in this study can be more easily utilized by engineers in designing or operating an AAA system in practice, since it requires simple characterization of wastewater COD.

  2. Aerobic and resistance exercise reinforcement and discomfort tolerance predict meeting activity guidelines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Understanding individual-differences of those people who do and do not meet physical activity recommendations could inform targets for increasing physical activity. Exercise reinforcement may be one such individual-level determinate, but it is not yet known whether those who meet activi...

  3. 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

  4. Clay enhancement of methane, low molecular weight hydrocarbon and halocarbon conversion by methanotrophic bacteria

    DOEpatents

    Apel, William A.; Dugan, Patrick R.

    1995-04-04

    An apparatus and method for increasing the rate of oxidation of toxic vapors by methanotrophic bacteria. The toxic vapors of interest are methane and trichloroethylene. The apparatus includes a gas phase bioreactor within a closed loop pumping system or a single pass system. The methanotrophic bacteria include Methylomonas methanica, Methylosinus trichosporium, and uncharacterized environmental enrichments.

  5. Clay enhancement of methane, low molecular weight hydrocarbon and halocarbon conversion by methanotrophic bacteria

    DOEpatents

    Apel, William A.; Dugan, Patrick R.

    1995-01-01

    An apparatus and method for increasing the rate of oxidation of toxic vapors by methanotrophic bacteria. The toxic vapors of interest are methane and trichloroethylene. The apparatus includes a gas phase bioreactor within a closed loop pumping system or a single pass system. The methanotrophic bacteria include Methylomonas methanica, Methylosinus trichosporium, and uncharacterized environmental enrichments.

  6. Mitochondrial aerobic respiration is activated during hair follicle stem cell differentiation, and its dysfunction retards hair regeneration

    PubMed Central

    Tang, Yan; Luo, Binping; Deng, Zhili; Wang, Ben; Liu, Fangfen; Li, Jinmao; Shi, Wei; Xie, Hongfu; Hu, Xingwang

    2016-01-01

    Background. Emerging research revealed the essential role of mitochondria in regulating stem/progenitor cell differentiation of neural progenitor cells, mesenchymal stem cells and other stem cells through reactive oxygen species (ROS), Notch or other signaling pathway. Inhibition of mitochondrial protein synthesis results in hair loss upon injury. However, alteration of mitochondrial morphology and metabolic function during hair follicle stem cells (HFSCs) differentiation and how they affect hair regeneration has not been elaborated upon. Methods. We compared the difference in mitochondrial morphology and activity between telogen bulge cells and anagen matrix cells. Expression levels of mitochondrial ROS and superoxide dismutase 2 (SOD2) were measured to evaluate redox balance. In addition, the level of pyruvate dehydrogenase kinase (PDK) and pyruvate dehydrogenase (PDH) were estimated to present the change in energetic metabolism during differentiation. To explore the effect of the mitochondrial metabolism on regulating hair regeneration, hair growth was observed after application of a mitochondrial respiratory inhibitor upon hair plucking. Results. During HFSCs differentiation, mitochondria became elongated with more abundant organized cristae and showed higher activity in differentiated cells. SOD2 was enhanced for redox balance with relatively stable ROS levels in differentiated cells. PDK increased in HFSCs while differentiated cells showed enhanced PDH, indicating that respiration switched from glycolysis to oxidative phosphorylation during differentiation. Inhibiting mitochondrial respiration in differentiated hair follicle cells upon hair plucking repressed hair regeneration in vivo. Conclusions. Upon HFSCs differentiation, mitochondria are elongated with more abundant cristae and show higher activity, accompanying with activated aerobic respiration in differentiated cells for higher energy supply. Also, dysfunction of mitochondrial respiration delays hair

  7. Binding of dicamba to soluble and bound extracellular polymeric substances (EPS) from aerobic activated sludge: a fluorescence quenching study.

    PubMed

    Pan, Xiangliang; Liu, Jing; Zhang, Daoyong; Chen, Xi; Song, Wenjuan; Wu, Fengchang

    2010-05-15

    Binding of dicamba to soluble EPS (SEPS) and bound EPS (BEPS) from aerobic activated sludge was investigated using fluorescence spectroscopy. Two protein-like fluorescence peaks (peak A with Ex/Em=225 nm/342-344 nm and peak B with Ex/Em=275/340-344 nm) were identified in SEPS and BEPS. Humic-like fluorescence peak C (Ex/Em=270-275 nm/450-460 nm) was only found in BEPS. Fluorescence of the peaks A and B for SEPS and peak A for BEPS were markedly quenched by dicamba at all temperatures whereas fluorescence of peaks B and C for BEPS was quenched only at 298 K. A dynamic process dominated the fluorescence quenching of peak A of both SEPS and BEPS. Fluorescence quenching of peak B and C was governed a static process. The effective quenching constants (logK(a)) were 4.725-5.293 for protein-like fluorophores of SEPS and 4.23-5.190 for protein-like fluorophores of BEPS, respectively. LogK(a) for humic-like substances was 3.85. Generally, SEPS had greater binding capacity for dicamba than BEPS, and protein-like substances bound dicamba more strongly than humic-like substances. Binding of dicamba to SEPS and BEPS was spontaneous and exothermic. Electrostatic force and hydrophobic interaction forces play a crucial role in binding of dicamba to EPS.

  8. Modelling aerobic biodegradation in vertical flow sand filters: impact of operational considerations on oxygen transfer and bacterial activity.

    PubMed

    Petitjean, A; Forquet, N; Wanko, A; Laurent, J; Molle, P; Mosé, R; Sadowski, A

    2012-05-01

    Oxygen renewal, as a prominent phenomenon for aerobic bacterial activity, deeply impacts Vertical Flow Constructed Wetland (VFCW) treatment efficiency. We introduce a multiphase model able to simulate multi-component transfer in VFCWs. It is based on a two-phase flow module, and a transport module. The flow module can quantify both water and air velocities throughout the filter during operation. The reactive transport module follows dissolved and gaseous oxygen concentrations, and the transport of solutes such as ammonium and readily biodegradable COD (Chemical Oxygen Demand). The consumption of components is governed by Monod-type kinetics. Heterotrophic and autotrophic bacteria, which are responsible for COD and ammonium degradation respectively, are part of the model components. The kinetics are based on the Constructed Wetlands Model 1. The results from the simulation tool were compared with existing experimental data, and two kinds of operation with VFCWs were investigated. The authors show strong interplay between oxygen renewal and bacterial consumption in case of sequential batch feeding with transient flooding of surface. Oxygen renewal is essentially convection mediated in such operation, while convection is not significant in non-flooding operation. Simulated bacterial patterns are impacted by the operation, both quantitatively and spatially. From a modelling point of view, the authors highlight some limitations of the biological model: the description of bacterial lysis processes needs to be enhanced, as well as ammonium adsorption to organic matter.

  9. Effect of salinity on extracellular polymeric substances of activated sludge from an anoxic-aerobic sequencing batch reactor.

    PubMed

    Wang, Zichao; Gao, Mengchun; Wang, Zhe; She, Zonglian; Chang, Qingbo; Sun, Changqing; Zhang, Jian; Ren, Yun; Yang, Ning

    2013-11-01

    The effect of salinity on extracellular polymeric substances (EPS) of activated sludge was investigated in an anoxic-aerobic sequencing batch reactor (SBR). The contents of loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS) were positively correlated with the salinity. The polysaccharide (PS) and protein (PN) contents in both LB-EPS and TB-EPS increased with the increase of salinity. With the increase of salinity from 0.5% to 6%, the PN/PS ratios in LB-EPS and TB-EPS decreased from 4.8 to 0.9 and from 2.9 to 1.4, respectively. The four fluorescence peaks in both LB-EPS and TB-EPS identified by three-dimensional excitation-emission matrix fluorescence spectroscopy are attributed to PN-like substances and humic acid-like substances. The Fourier transform infrared spectra of the LB-EPS and TB-EPS appeared to be very similar, but the differences across the spectra were apparent in terms of the relative intensity of some bands with the increase of salinity. The sludge volume index showed a linear correlation with LB-EPS (R(2)=0.9479) and TB-EPS (R(2)=0.9355) at different salinities, respectively.

  10. Repeated high-speed activities during youth soccer games in relation to changes in maximal sprinting and aerobic speeds.

    PubMed

    Buchheit, M; Simpson, B M; Mendez-Villanueva, A

    2013-01-01

    The aim of this study was to examine in highly-trained young soccer players whether substantial changes in either maximal sprinting speed (MSS) or maximal aerobic speed (as inferred from peak incremental test speed, V(Vam-Eval)) can affect repeated high-intensity running during games. Data from 33 players (14.5±1.3 years), who presented substantial changes in either MSS or V(Vam-Eval) throughout 2 consecutive testing periods (~3 months) were included in the final analysis. For each player, time-motion analyses were performed using a global positioning system (1-Hz) during 2-10 international club games played within 1-2 months from/to each testing period of interest (n for game analyzed=109, player-games=393, games per player per period=4±2). Sprint activities were defined as at least a 1-s run at intensities higher than 61% of individual MSS. Repeated-sprint sequences (RSS) were defined as a minimum of 2 consecutive sprints interspersed with a maximum of 60 s of recovery. Improvements in both MSS and V(Vam-Eval) were likely associated with a decreased RSS occurrence, but in some positions only (e. g., - 24% vs. - 3% for improvements in MSS in strikers vs. midfielders, respectively). The changes in the number of sprints per RSS were less clear but also position-dependent, e. g., +7 to +12% for full-backs and wingers, - 5 to - 7% for centre-backs and midfielders. In developing soccer players, changes in repeated-sprint activity during games do not necessarily match those in physical fitness. Game tactical and strategic requirements are likely to modulate on-field players' activity patterns independently (at least partially) of players' physical capacities.

  11. Continuous Aerobic Training in Individualized Intensity Avoids Spontaneous Physical Activity Decline and Improves MCT1 Expression in Oxidative Muscle of Swimming Rats

    PubMed Central

    Scariot, Pedro P. M.; Manchado-Gobatto, Fúlvia de Barros; Torsoni, Adriana S.; dos Reis, Ivan G. M.; Beck, Wladimir R.; Gobatto, Claudio A.

    2016-01-01

    Although aerobic training has been shown to affect the lactate transport of skeletal muscle, there is no information concerning the effect of continuous aerobic training on spontaneous physical activity (SPA). Because every movement in daily life (i.e., SPA) is generated by skeletal muscle, we think that it is possible that an improvement of SPA could affect the physiological properties of muscle with regard to lactate transport. The aim of this study was to evaluate the effect of 12 weeks of continuous aerobic training in individualized intensity on SPA of rats and their gene expressions of monocarboxylate transporters (MCT) 1 and 4 in soleus (oxidative) and white gastrocnemius (glycolytic) muscles. We also analyzed the effect of continuous aerobic training on aerobic and anaerobic parameters using the lactate minimum test (LMT). Sixty-day-old rats were randomly divided into three groups: a baseline group in which rats were evaluated prior to initiation of the study; a control group (Co) in which rats were kept without any treatment during 12 weeks; and a chronic exercise group (Tr) in which rats swam for 40 min/day, 5 days/week at 80% of anaerobic threshold during 12 weeks. After the experimental period, SPA of rats was measured using a gravimetric method. Rats had their expression of MCTs determined by RT-PCR analysis. In essence, aerobic training is effective in maintaining SPA, but did not prevent the decline of aerobic capacity and anaerobic performance, leading us to propose that the decline of SPA is not fully attributed to a deterioration of physical properties. Changes in SPA were concomitant with changes in MCT1 expression in the soleus muscle of trained rats, suggestive of an additional adaptive response toward increased lactate clearance. This result is in line with our observation showing a better equilibrium on lactate production-remotion during the continuous exercise (LMT). We propose an approach to combat the decline of SPA of rats in their home

  12. Changes in aerobic performance, body composition, and physical activity in polar explorers during a year-long stay at the polar station in the Arctic

    NASA Astrophysics Data System (ADS)

    Maciejczyk, Marcin; Araźny, Andrzej; Opyrchał, Marta

    2016-09-01

    The aim of this study was to evaluate changes in physical activity, aerobic performance, and body composition in polar explorers during a 1-year stay at the polar station. The study group consisted of 10 people, including 8 men and 2 women. Aerobic performance (maximal oxygen uptake), physical activity, body mass, and composition were evaluated for the polar explores of the Polish Polar Station prior to departure, and then during their stay at the station for a period of 1 year. The measurements were performed every 3 months. Compared to the measurements taken before going to the polar station, aerobic performance significantly (p = 0.02) increased in the first 3 months of residing at the polar station and then remained relatively stable for the following duration of the stay. In the first 3 months of the stay, we also observed the highest level of physical activity in participants. In the polar explorers, no significant (p > 0.05) body fatness changes were noted. Nonetheless, lean body mass, body mass, and BMI significantly increased compared to the measurements taken before departure to the polar station. The greatest changes in aerobic performance, physical activity, and body composition were observed during the first 3 months after arrival to the Arctic and then, despite changing biometeorological conditions, they remained stable for the next months of the stay. We recommend the introduction of a physical preparation program before departing to the polar station to improve explorers' physical fitness, so that they can meet the physical challenges they are faced with immediately after arrival to the polar station.

  13. High catalytic activity of palladium(II)-exchanged mesoporous sodalite and NaA zeolite for bulky aryl coupling reactions: reusability under aerobic conditions.

    PubMed

    Choi, Minkee; Lee, Dong-Hwan; Na, Kyungsu; Yu, Byung-Woo; Ryoo, Ryong

    2009-01-01

    Exchange for the better: Mesoporous sodalite and NaA zeolite exchanged with Pd(2+) exhibit remarkably high activity and reusability in C-C coupling reactions under aerobic atmosphere. It is proposed that the catalytic reactions are mediated by a molecular Pd(0) species generated in situ within the pores (see picture), which is oxidized back to Pd(2+) by O(2), preventing the formation of catalytically inactive Pd(0) agglomerates.

  14. Changes in aerobic performance, body composition, and physical activity in polar explorers during a year-long stay at the polar station in the Arctic.

    PubMed

    Maciejczyk, Marcin; Araźny, Andrzej; Opyrchał, Marta

    2016-09-14

    The aim of this study was to evaluate changes in physical activity, aerobic performance, and body composition in polar explorers during a 1-year stay at the polar station. The study group consisted of 10 people, including 8 men and 2 women. Aerobic performance (maximal oxygen uptake), physical activity, body mass, and composition were evaluated for the polar explores of the Polish Polar Station prior to departure, and then during their stay at the station for a period of 1 year. The measurements were performed every 3 months. Compared to the measurements taken before going to the polar station, aerobic performance significantly (p = 0.02) increased in the first 3 months of residing at the polar station and then remained relatively stable for the following duration of the stay. In the first 3 months of the stay, we also observed the highest level of physical activity in participants. In the polar explorers, no significant (p > 0.05) body fatness changes were noted. Nonetheless, lean body mass, body mass, and BMI significantly increased compared to the measurements taken before departure to the polar station. The greatest changes in aerobic performance, physical activity, and body composition were observed during the first 3 months after arrival to the Arctic and then, despite changing biometeorological conditions, they remained stable for the next months of the stay. We recommend the introduction of a physical preparation program before departing to the polar station to improve explorers' physical fitness, so that they can meet the physical challenges they are faced with immediately after arrival to the polar station.

  15. Resistance Exercise in Already-Active Diabetic Individuals (READI): study rationale, design and methods for a randomized controlled trial of resistance and aerobic exercise in type 1 diabetes.

    PubMed

    Yardley, Jane E; Kenny, Glen P; Perkins, Bruce A; Riddell, Michael C; Goldfield, Gary S; Donovan, Lois; Hadjiyannakis, Stasia; Wells, George A; Phillips, Penny; Sigal, Ronald J

    2015-03-01

    The Resistance Exercise in Already Active Diabetic Individuals (READI) trial aimed to examine whether adding a 6-month resistance training program would improve glycemic control (as reflected in reduced HbA₁c) in individuals with type 1 diabetes who were already engaged in aerobic exercise compared to aerobic training alone. After a 5-week run-in period including optimization of diabetes care and low-intensity exercise, 131 physically active adults with type 1 diabetes were randomized to two groups for 22weeks: resistance training three times weekly, or waiting-list control. Both groups maintained the same volume, duration and intensity of aerobic exercise throughout the study as they did at baseline. HbA₁c, body composition, frequency of hypoglycemia, lipids, blood pressure, apolipoproteins B and A-1 (ApoB and ApoA1), the ApoB-ApoA1 ratio, urinary albumin excretion, serum C-reactive protein, free fatty acids, total daily insulin dose, health-related quality of life, cardiorespiratory fitness and musculoskeletal fitness were recorded at baseline, 3 (for some variables), and 6 months. To our knowledge, READI is the only trial to date assessing the incremental health-related impact of adding resistance training for individuals with type 1 diabetes who are already aerobically active. Few exercise trials have been completed in this population, and even fewer have assessed resistance exercise. With recent improvements in the quality of diabetes care, the READI study will provide conclusive evidence to support or refute a major clinically relevant effect of exercise type in the recommendations for physical activity in patients with type 1 diabetes.

  16. Aerobic biotransformation and fate of N-ethyl perfluorooctane sulfonamidoethanol (N-EtFOSE) in activated sludge.

    PubMed

    Rhoads, Kurt R; Janssen, Elisabeth M L; Luthy, Richard G; Criddle, Craig S

    2008-04-15

    Processes affecting the fate of perfluorinated organics are of increasing concern due to the global dispersal, persistence, and bioaccumulation of these contaminants. The volatile compound N-ethyl perfluorooctane sulfonamidoethanol (N-EtFOSE) and its phosphate esters have been used in protective surface coatings. In this report, we describe the fate of N-EtFOSE in aerobic batch assays. These assays were performed using undiluted activated sludge in serum bottles that were sealed to prevent the escape of N-EtFOSE and volatile transformation products. Separate assays were performed with N-EtFOSE and reported transformation products. N-EtFOSE degraded to N-ethyl perfluorooctane sulfonamido acetic acid (N-EtFOSAA) with an observed first-order rate of 0.99 +/- 0.08 day(-1) and a pseudosecond order rate of 0.26 +/- 0.02 L/mg VSS day(-1). N-EtFOSAA underwent further transformation at a slower rate (0.093 +/- 0.012 day(-1)) to N-ethylperfluorooctane sulfonamide (N-EtFOSA). N-EtFOSA then transformed to perfluorooctane sulfonamide (FOSA). FOSA transformed to perfluorooctane sulfinate (PFOSI), and PFOSI transformed to perfluorooctane sulfonate (PFOS). Perfluorooctanoic acid (PFOA) was not detected as a transformation product of any compound. Using the measured rate of N-EtFOSE biotransformation and literature values for phase partitioning and mass transfer in aeration basins, we modeled the fate of N-EtFOSE in a typical activated sludge aeration basin open to the atmosphere. The model predicts that 76% of the N-EtFOSE is stripped into the atmosphere, 5% sorbs to waste solids, 13% undergoes transformation to N-EtFOSAA, and 6% is discharged in the wastewater effluent.

  17. Carbon isotopic fractionation in lipids from methanotrophic bacteria: relevance for interpretation of the geochemical record of biomarkers

    NASA Technical Reports Server (NTRS)

    Summons, R. E.; Jahnke, L. L.; Roksandic, Z.

    1994-01-01

    Experiments with cultured aerobic methane oxidising bacteria confirm that their biomarker lipids will be significantly depleted in 13C compared to the substrate. The methanotrophic bacteria Methylococcus capsulatus and Methylomonas methanica, grown on methane and using the RuMP cycle for carbon assimilation, show maximum 13C fractionation of approximately 30% in the resultant biomass. In M. capsulatus, the maximum fractionation is observed in the earliest part of the exponential growth stage and decreases to approximately 16% as cells approach stationary phase. This change may be associated with a shift from the particulate form to the soluble form of the methane monooxygenase enzyme. Less than maximum fractionation is observed when cells are grown with reduced methane availability. Biomass of M. capsulatus grown on methanol was depleted by 9% compared to the substrate. Additional strong 13C fractionation takes place during polyisoprenoid biosynthesis in methanotrophs. The delta 13C values of individual hopanoid and steroid biomarkers produced by these organisms were as much as l0% more negative than total biomass. In individual cultures, squalene was 13C-enriched by as much as 14% compared to the triterpane skeleton of bacteriohopaneaminopentol. Much of the isotopic dispersion in lipid metabolites could be attributed to shifts in their relative abundances, combined with an overall reduction in fractionation during the growth cycle. In cells grown on methanol, where there was no apparent effect of growth stage on overall fractionation there were still significant isotopic differences between closely related lipids including a 5.3% difference between the hopane and 3 beta-methylhopane skeletons. Hopane and sterane polyisoprenoids were also 13C-depleted compared to fatty acids. These observations have significant implications for the interpretation of specific compound isotopic signatures now being measured for hydrocarbons and other lipids present in sediments and

  18. Bioconversion of methane to lactate by an obligate methanotrophic bacterium

    SciTech Connect

    Henard, Calvin A.; Smith, Holly; Dowe, Nancy; Kalyuzhnaya, Marina G.; Pienkos, Philip T.; Guarnieri, Michael T.

    2016-02-23

    Methane is the second most abundant greenhouse gas (GHG), with nearly 60% of emissions derived from anthropogenic sources. Microbial conversion of methane to fuels and value-added chemicals offers a means to reduce GHG emissions, while also valorizing this otherwise squandered high-volume, high-energy gas. However, to date, advances in methane biocatalysis have been constrained by the low-productivity and limited genetic tractability of natural methane-consuming microbes. Here, leveraging recent identification of a novel, tractable methanotrophic bacterium, Methylomicrobium buryatense, we demonstrate microbial biocatalysis of methane to lactate, an industrial platform chemical. Heterologous overexpression of a Lactobacillus helveticus L-lactate dehydrogenase in M. buryatense resulted in an initial titer of 0.06 g lactate/L from methane. Cultivation in a 5 L continuously stirred tank bioreactor enabled production of 0.8 g lactate/L, representing a 13-fold improvement compared to the initial titer. The yields (0.05 g lactate/g methane) and productivity (0.008 g lactate/L/h) indicate the need and opportunity for future strain improvement. Additionally, real-time analysis of methane utilization implicated gas-to-liquid transfer and/or microbial methane consumption as process limitations. This work opens the door to develop an array of methanotrophic bacterial strain-engineering strategies currently employed for biocatalytic sugar upgrading to “green” chemicals and fuels.

  19. Bioconversion of methane to lactate by an obligate methanotrophic bacterium

    DOE PAGES

    Henard, Calvin A.; Smith, Holly; Dowe, Nancy; ...

    2016-02-23

    Methane is the second most abundant greenhouse gas (GHG), with nearly 60% of emissions derived from anthropogenic sources. Microbial conversion of methane to fuels and value-added chemicals offers a means to reduce GHG emissions, while also valorizing this otherwise squandered high-volume, high-energy gas. However, to date, advances in methane biocatalysis have been constrained by the low-productivity and limited genetic tractability of natural methane-consuming microbes. Here, leveraging recent identification of a novel, tractable methanotrophic bacterium, Methylomicrobium buryatense, we demonstrate microbial biocatalysis of methane to lactate, an industrial platform chemical. Heterologous overexpression of a Lactobacillus helveticus L-lactate dehydrogenase in M. buryatense resultedmore » in an initial titer of 0.06 g lactate/L from methane. Cultivation in a 5 L continuously stirred tank bioreactor enabled production of 0.8 g lactate/L, representing a 13-fold improvement compared to the initial titer. The yields (0.05 g lactate/g methane) and productivity (0.008 g lactate/L/h) indicate the need and opportunity for future strain improvement. Additionally, real-time analysis of methane utilization implicated gas-to-liquid transfer and/or microbial methane consumption as process limitations. This work opens the door to develop an array of methanotrophic bacterial strain-engineering strategies currently employed for biocatalytic sugar upgrading to “green” chemicals and fuels.« less

  20. Bioconversion of methane to lactate by an obligate methanotrophic bacterium.

    PubMed

    Henard, Calvin A; Smith, Holly; Dowe, Nancy; Kalyuzhnaya, Marina G; Pienkos, Philip T; Guarnieri, Michael T

    2016-02-23

    Methane is the second most abundant greenhouse gas (GHG), with nearly 60% of emissions derived from anthropogenic sources. Microbial conversion of methane to fuels and value-added chemicals offers a means to reduce GHG emissions, while also valorizing this otherwise squandered high-volume, high-energy gas. However, to date, advances in methane biocatalysis have been constrained by the low-productivity and limited genetic tractability of natural methane-consuming microbes. Here, leveraging recent identification of a novel, tractable methanotrophic bacterium, Methylomicrobium buryatense, we demonstrate microbial biocatalysis of methane to lactate, an industrial platform chemical. Heterologous overexpression of a Lactobacillus helveticus L-lactate dehydrogenase in M. buryatense resulted in an initial titer of 0.06 g lactate/L from methane. Cultivation in a 5 L continuously stirred tank bioreactor enabled production of 0.8 g lactate/L, representing a 13-fold improvement compared to the initial titer. The yields (0.05 g lactate/g methane) and productivity (0.008 g lactate/L/h) indicate the need and opportunity for future strain improvement. Additionally, real-time analysis of methane utilization implicated gas-to-liquid transfer and/or microbial methane consumption as process limitations. This work opens the door to develop an array of methanotrophic bacterial strain-engineering strategies currently employed for biocatalytic sugar upgrading to "green" chemicals and fuels.

  1. Bioconversion of methane to lactate by an obligate methanotrophic bacterium

    PubMed Central

    Henard, Calvin A.; Smith, Holly; Dowe, Nancy; Kalyuzhnaya, Marina G.; Pienkos, Philip T.; Guarnieri, Michael T.

    2016-01-01

    Methane is the second most abundant greenhouse gas (GHG), with nearly 60% of emissions derived from anthropogenic sources. Microbial conversion of methane to fuels and value-added chemicals offers a means to reduce GHG emissions, while also valorizing this otherwise squandered high-volume, high-energy gas. However, to date, advances in methane biocatalysis have been constrained by the low-productivity and limited genetic tractability of natural methane-consuming microbes. Here, leveraging recent identification of a novel, tractable methanotrophic bacterium, Methylomicrobium buryatense, we demonstrate microbial biocatalysis of methane to lactate, an industrial platform chemical. Heterologous overexpression of a Lactobacillus helveticus L-lactate dehydrogenase in M. buryatense resulted in an initial titer of 0.06 g lactate/L from methane. Cultivation in a 5 L continuously stirred tank bioreactor enabled production of 0.8 g lactate/L, representing a 13-fold improvement compared to the initial titer. The yields (0.05 g lactate/g methane) and productivity (0.008 g lactate/L/h) indicate the need and opportunity for future strain improvement. Additionally, real-time analysis of methane utilization implicated gas-to-liquid transfer and/or microbial methane consumption as process limitations. This work opens the door to develop an array of methanotrophic bacterial strain-engineering strategies currently employed for biocatalytic sugar upgrading to “green” chemicals and fuels. PMID:26902345

  2. Stability of Trifluoromethane in Forest Soils and Methanotrophic Cultures

    NASA Technical Reports Server (NTRS)

    King, Gary M.

    1997-01-01

    Trifluoromethane (TFM) has been reported as an endproduct of trifluoroacetate degradation under oxic conditions. Although other halomethanes, such as chloroform, methyl bromide, and methyl fluoride, inhibit methane oxidation or are degraded by methanotrophs, the fate of TFM is unknown. TFM had no affect on atmospheric methane consumption when added to forest soils at either 10 ppm or 10,000 ppm. No degradation of TFM was observed at either concentration for incubations of 6 days. Cultures of Methylobacter albus BG8 and Methylosinus trichosporium OB3b grown With and without added copper were also used to assay TFM degradation at 10 10000 ppm levels. TFM did not inhibit methane oxidation under any growth conditions, including those inducing expression of soluble methane monooxygenase, nor was it degraded at measurable rates. In contrast, parallel assays showed that both methyl fluoride and chloroform inhibited methane oxidation in M. trichosporium OB3b. Our results suggest that TFM may be relatively inert with respect to methanotrophic degradition. Although TFM has a negligible ozone depletion potential, it absorbs infrared radiation and has a relatively long atmospheric residence time. Thus, accumulation of TFM in the atmosphere as a consequence of the decomposition of hydrochlorofluorocarbons may have significant unpredicted climate impacts.

  3. Activation of molecular oxygen by infrared laser radiation in pigment-free aerobic systems.

    PubMed

    Krasnovsky, A A; Drozdova, N N; Ivanov, A V; Ambartsumian, R V

    2003-09-01

    With the goal of mimicking the mechanisms of the biological effects of low energy laser irradiation, we have shown that infrared low intensity laser radiation causes oxygenation of the chemical traps of singlet oxygen dissolved in organic media and water saturated by air at normal atmospheric pressure. The photooxygenation rate was directly proportional to the oxygen concentration and strongly inhibited by the singlet oxygen quenchers. The maximum of the photooxygenation action spectrum coincided with the maximum of the oxygen absorption band at 1270 nm. The data provide unambiguous evidence that photooxygenation is determined by the reactive singlet (1)Delta(g )state formed as a result of direct laser excitation of molecular oxygen. Hence, activation of oxygen caused by its direct photoexcitation may occur in natural systems.

  4. Environmental control on aerobic methane oxidation in coastal waters

    NASA Astrophysics Data System (ADS)

    Steinle, Lea; Maltby, Johanna; Engbersen, Nadine; Zopfi, Jakob; Bange, Hermann; Elvert, Marcus; Hinrichs, Kai-Uwe; Kock, Annette; Lehmann, Moritz; Treude, Tina; Niemann, Helge

    2016-04-01

    Large quantities of methane are produced in anoxic sediments of continental margins and may be liberated to the overlying water column, where some of it is consumed by aerobic methane oxidizing bacteria (MOB). Aerobic methane oxidation (MOx) in the water column is consequently the final sink for methane before its release to the atmosphere, where it acts as a potent greenhouse gas. In the context of the ocean's contribution to atmospheric methane, coastal seas are particularly important accounting >75% of global methane emission from marine systems. Coastal oceans are highly dynamic, in particular with regard to the variability of methane and oxygen concentrations as well as temperature and salinity, all of which are potential key environmental factors controlling MOx. To determine important environmental controls on the activity of MOBs in coastal seas, we conducted a two-year time-series study with measurements of physicochemical water column parameters, MOx activity and the composition of the MOB community in a coastal inlet in the Baltic Sea (Boknis Eck Time Series Station, Eckernförde Bay - E-Bay). In addition, we investigated the influence of temperature and oxygen on MOx during controlled laboratory experiments. In E-Bay, hypoxia developed in bottom waters towards the end of the stratification period. Constant methane liberation from sediments resulted in bottom water methane accumulations and supersaturation (with respect to the atmospheric equilibrium) in surface waters. Here, we will discuss the factors impacting MOx the most, which were (i) perturbations of the water column (ii) temperature and (iii) oxygen concentration. (i) Perturbations of the water column caused by storm events or seasonal mixing led to a decrease in MOx, probably caused by replacement of stagnant water with a high standing stock of MOB by 'new' waters with a lower abundance of methanotrophs. b) An increase in temperature generally led to higher MOx rates. c) Even though methane was

  5. Self-reported physical activity and objective aerobic fitness: differential associations with gray matter density in healthy aging

    PubMed Central

    Zlatar, Zvinka Z.; McGregor, Keith M.; Towler, Stephen; Nocera, Joe R.; Dzierzewski, Joseph M.; Crosson, Bruce

    2015-01-01

    Aerobic fitness (AF) and self-reported physical activity (srPA) do not represent the same construct. However, many exercise and brain aging studies interchangeably use AF and srPA measures, which may be problematic with regards to how these metrics are associated with brain outcomes, such as morphology. If AF and PA measures captured the same phenomena, regional brain volumes associated with these measures should directly overlap. This study employed the general linear model to examine the differential association between objectively-measured AF (treadmill assessment) and srPA (questionnaire) with gray matter density (GMd) in 29 cognitively unimpaired community-dwelling older adults using voxel based morphometry. The results show significant regional variance in terms of GMd when comparing AF and srPA as predictors. Higher AF was associated with greater GMd in the cerebellum only, while srPA displayed positive associations with GMd in occipito-temporal, left perisylvian, and frontal regions after correcting for age. Importantly, only AF level, and not srPA, modified the relationship between age and GMd, such that higher levels of AF were associated with increased GMd in older age, while decreased GMd was seen in those with lower AF as a function of age. These results support existing literature suggesting that both AF and PA exert beneficial effects on GMd, but only AF served as a buffer against age-related GMd loss. Furthermore, these results highlight the need for use of objective PA measurement and comparability of tools across studies, since results vary dependent upon the measures used and whether these are objective or subjective in nature. PMID:25691866

  6. Soluble methane monooxygenase component B gene probe for identification of methanotrophs that rapidly degrade trichloroethylene.

    PubMed Central

    Tsien, H C; Hanson, R S

    1992-01-01

    Restriction fragment length polymorphisms, Western blot (immunoblot) analysis, and fluorescence-labelled signature probes were used for the characterization of methanotrophic bacteria as well as for the identification of methanotrophs which contained the soluble methane monooxygenase (MMO) gene and were able to degrade trichloroethylene (TCE). The gene encoding a soluble MMO component B protein from Methylosinus trichosporium OB3b was cloned. It contained a 2.2-kb EcoRI fragment. With this cloned component B gene as probe, methanotroph types I, II, and X and environmental and bioreactor samples were screened for the presence of the gene encoding soluble MMO. Fragments produced by digestion of DNA with rare cutting restriction endonucleases were separated by pulsed-field gel electrophoresis and transferred to Zeta-Probe membrane (Bio-Rad) for Southern blot analysis. Samples were also analyzed for the presence of soluble MMO by Western blot analysis and the ability to degrade TCE. The physiological groups of methanotrophs in each sample were determined by hybridizing cells with fluorescence-labelled signature probes. Among twelve pure or mixed cultures, DNA fragments of seven methanotrophs hybridized with the soluble MMO B gene probe. When grown in media with limited copper, all of these bacteria degraded TCE. All of them are type II methanotrophs. The soluble MMO component B gene of the type X methanotroph, Methylococcus capsulatus Bath, did not hybridize to the M. trichosporium OB3b soluble MMO component B gene probe, although M. capsulatus Bath also produces a soluble MMO. Images PMID:1349468

  7. Detection, Isolation, and Characterization of Acidophilic Methanotrophs from Sphagnum Mosses ▿ †

    PubMed Central

    Kip, Nardy; Ouyang, Wenjing; van Winden, Julia; Raghoebarsing, Ashna; van Niftrik, Laura; Pol, Arjan; Pan, Yao; Bodrossy, Levente; van Donselaar, Elly G.; Reichart, Gert-Jan; Jetten, Mike S. M.; Sinninghe Damsté, Jaap S.; Op den Camp, Huub J. M.

    2011-01-01

    Sphagnum peatlands are important ecosystems in the methane cycle. Methane-oxidizing bacteria in these ecosystems serve as a methane filter and limit methane emissions. Yet little is known about the diversity and identity of the methanotrophs present in and on Sphagnum mosses of peatlands, and only a few isolates are known. The methanotrophic community in Sphagnum mosses, originating from a Dutch peat bog, was investigated using a pmoA microarray. A high biodiversity of both gamma- and alphaproteobacterial methanotrophs was found. With Sphagnum mosses as the inoculum, alpha- and gammaproteobacterial acidophilic methanotrophs were isolated using established and newly designed media. The 16S rRNA, pmoA, pxmA, and mmoX gene sequences showed that the alphaproteobacterial isolates belonged to the Methylocystis and Methylosinus genera. The Methylosinus species isolated are the first acid-tolerant members of this genus. Of the acidophilic gammaproteobacterial strains isolated, strain M5 was affiliated with the Methylomonas genus, and the other strain, M200, may represent a novel genus, most closely related to the genera Methylosoma and Methylovulum. So far, no acidophilic or acid-tolerant methanotrophs in the Gammaproteobacteria class are known. All strains showed the typical features of either type I or II methanotrophs and are, to the best of our knowledge, the first isolated (acidophilic or acid-tolerant) methanotrophs from Sphagnum mosses. PMID:21724892

  8. Soluble Methane Monooxygenase Production and Trichloroethylene Degradation by a Type I Methanotroph, Methylomonas methanica 68-1

    PubMed Central

    Koh, Sung-Cheol; Bowman, John P.; Sayler, Gary S.

    1993-01-01

    A methanotroph (strain 68-1), originally isolated from a trichloroethylene (TCE)-contaminated aquifer, was identified as the type I methanotroph Methylomonas methanica on the basis of intracytoplasmic membrane ultrastructure, phospholipid fatty acid profile, and 16S rRNA signature probe hybridization. Strain 68-1 was found to oxidize naphthalene and TCE via a soluble methane monooxygenase (sMMO) and thus becomes the first type I methanotroph known to be able to produce this enzyme. The specific whole-cell sMMO activity of 68-1, as measured by the naphthalene oxidation assay and by TCE biodegradation, was comparatively higher than sMMO activity levels in Methylosinus trichosporium OB3b grown in the same copper-free conditions. The maximal naphthalene oxidation rates of Methylomonas methanica 68-1 and Methylosinus trichosporium OB3b were 551 ± 27 and 321 ± 16 nmol h-1 mg of protein -1, respectively. The maximal TCE degradation rates of Methylomonas methanica 68-1 and Methylosinus trichosporium OB3b were 2,325 ± 260 and 995 ± 160 nmol h-1 mg of protein-1, respectively. The substrate affinity of 68-1 sMMO to naphthalene (Km, 70 ± 4 μM) and TCE (Km, 225 ± 13 μM), however, was comparatively lower than that of the sMMO of OB3b, which had affinities of 40 ± 3 and 126 ± 8 μM, respectively. Genomic DNA slot and Southern blot analyses with an sMMO gene probe from Methylosinus trichosporium OB3b showed that the sMMO genes of 68-1 have little genetic homology to those of OB3b. This result may indicate the evolutionary diversification of the sMMOs. Images PMID:16348920

  9. Optimization of diagnostic microarray for application in analysing landfill methanotroph communities under different plant covers.

    PubMed

    Stralis-Pavese, Nancy; Sessitsch, Angela; Weilharter, Alexandra; Reichenauer, Thomas; Riesing, Johann; Csontos, József; Murrell, J Colin; Bodrossy, Levente

    2004-04-01

    Landfill sites are responsible for 6-12% of global methane emission. Methanotrophs play a very important role in decreasing landfill site methane emissions. We investigated the methane oxidation capacity and methanotroph diversity in lysimeters simulating landfill sites with different plant vegetations. Methane oxidation rates were 35 g methane m-2 day-1 or higher for planted lysimeters and 18 g methane m-2 day-1 or less for bare soil controls. Best methane oxidation, as displayed by gas depth profiles, was found under a vegetation of grass and alfalfa. Methanotroph communities were analysed at high throughput and resolution using a microbial diagnostic microarray targeting the particulate methane monooxygenase (pmoA) gene of methanotrophs and functionally related bacteria. Members of the genera Methylocystis and Methylocaldum were found to be the dominant members in landfill site simulating lysimeters. Soil bacterial communities in biogas free control lysimeters, which were less abundant in methanotrophs, were dominated by Methylocaldum. Type Ia methanotrophs were found only in the top layers of bare soil lysimeters with relatively high oxygen and low methane concentrations. A competetive advantage of type II methanotrophs over type Ia methanotrophs was indicated under all plant covers investigated. Analysis of average and individual results from parallel samples was used to identify general trends and variations in methanotroph community structures in relation to depth, methane supply and plant cover. The applicability of the technology for the detection of environmental perturbations was proven by an erroneous result, where an unexpected community composition detected with the microarray indicated a potential gas leakage in the lysimeter being investigated.

  10. The effect of aerobic exercise training on growth performance, digestive enzyme activities and postprandial metabolic response in juvenile qingbo (Spinibarbus sinensis).

    PubMed

    Li, Xiu-Ming; Yu, Li-Juan; Wang, Chuan; Zeng, Ling-Qing; Cao, Zhen-Dong; Fu, Shi-Jian; Zhang, Yao-Guang

    2013-09-01

    Continual swimming exercise usually promotes growth in fish at a moderate water velocity. We hypothesized that the improvement in growth in exercise-trained fish may be accompanied by increases in digestive enzyme activity, respiratory capacity and, hence, postprandial metabolism. Juvenile qingbo fish (Spinibarbus sinensis) were subjected to aerobic training for 8weeks at a water velocity of control (3cms(-1)), 1, 2 and 4 body length (bl)s(-1) at a constant temperature of 25°C. The feed intake (FI), food conversion rate (FCR), specific growth rate (SGR), whole-body composition, trypsin and lipase activities, maximal oxygen consumption (M˙O2max) and postprandial M˙O2 response were measured at the end of the training period. Aerobic exercise training induced a significant increase in FI compared with the control group, while the FCR of the 4bls(-1) group was significantly lower than for the other three groups (P<0.05). The 1 and 2bls(-1) groups showed a significantly higher SGR over the control group (P<0.05). The whole-body fat and protein contents were significantly altered after aerobic exercise training (P<0.05). Furthermore, aerobic exercise training elevated the activity of both trypsin and lipase in the hepatopancreas and intestinal tract of juvenile S. sinensis. The M˙O2max of the 4bls(-1) training group was significantly higher than for the control group. The resting M˙O2 (M˙O2rest) and peak postprandial M˙O2 (M˙O2peak) in the three training groups were significantly higher than in the control group (P<0.05). Time to M˙O2peak was significantly shorter in the 1, 2 and 4bls(-1) training groups compared with the control group, while exercise training showed no effect on SDA (specific dynamic action) duration, factorial metabolic scope, energy expended on SDA and the SDA coefficient when compared to the control group. These data suggest that (1) the optimum water velocity for the growth of juvenile S. sinensis occurred at approximately 2.4bls(-1); (2

  11. Effect of nitrogen fertilization on the activity and diversity of methane oxidising bacteria in the littoral zone of a boreal lake

    NASA Astrophysics Data System (ADS)

    Saari, A.; Siljanen, H. M. P.; Hämäläinen, S.; Bodrossy, L.; Martikainen, P. J.

    2009-04-01

    Freshwater lakes are generally net sources of CH4 and in boreal lakes a major part of the CH4 emissions originates from the littoral zone during the ice-free season. Aerobic CH4 oxidising bacteria, methanotrophs, significantly limit the flux of CH4 to the atmosphere from sediments. Increased N load causes eutrophication and subsequent anoxia, which probably enhances CH4 production. In addition, inorganic nitrogen (ammonium and nitrate) can inhibit CH4 oxidation. Our study belongs to the research consortium METHECO (Eurodiversity programme of European Science Foundation), where the activity and diversity of methane oxidising bacteria are studied in various European ecosystems. We studied with in situ manipulation the effects of eutrophication (added nitrogen) on the activity and diversity of methanotrophs in a littoral wetland of a small and shallow hyper-eutrophic lake in east-central Finland. We established in the area growing sedges (7-10 m from the shore line) three sampling plots (1.2 m x 1.2 m), which were irrigated four times (from 4th July to 9th August) with ammonium nitrate solution giving 10 g N m-2for the total additional nitrogen load during the growing season. Three control plots were irrigated with equivalent amount of distilled water. The amount of added ammonium nitrate solution or water did not exceed 10% of the long-term (30 years) average rainfall in the area during the growing season. Sediment samples were taken from the depths of 0-2 cm, 2-10cm, 10-20 cm and 20-30 cm before, during and after the N treatment. Methane oxidation potential was studied in 550-ml flasks with sediment slurries and initial headspace CH4 concentration of 0.1%. The diversity of methanotrophs was studied with pmoA-microarray. Methane oxidation was most active in the organic surface sediment layer of 0-10 cm and the activity decreased with depth. Nitrogen addition in situ did not affect significantly the potential CH4 oxidation rates, although nitrate inhibited CH4

  12. Diversity and phylogeny of the ectoine biosynthesis genes in aerobic, moderately halophilic methylotrophic bacteria.

    PubMed

    Reshetnikov, Alexander S; Khmelenina, Valentina N; Mustakhimov, Ildar I; Kalyuzhnaya, Marina; Lidstrom, Mary; Trotsenko, Yuri A

    2011-11-01

    The genes of ectoine biosynthesis pathway were identified in six species of aerobic, slightly halophilic bacteria utilizing methane, methanol or methylamine. Two types of ectoine gene cluster organization were revealed in the methylotrophs. The gene cluster ectABC coding for diaminobutyric acid (DABA) acetyltransferase (EctA), DABA aminotransferase (EctB) and ectoine synthase (EctC) was found in methanotrophs Methylobacter marinus 7C and Methylomicrobium kenyense AMO1(T). In methanotroph Methylomicrobium alcaliphilum ML1, methanol-utilizers Methylophaga thalassica 33146(T) , Methylophaga alcalica M8 and methylamine-utilizer Methylarcula marina h1(T), the genes forming the ectABC-ask operon are preceded by ectR, encoding a putative transcriptional regulatory protein EctR. Phylogenetic relationships of the Ect proteins do not correlate with phylogenetic affiliation of the strains, thus implying that the ability of methylotrophs to produce ectoine is most likely the result of a horizontal transfer event.

  13. Activation of the FGFR1 signalling pathway by the Epstein-Barr virus-encoded LMP1 promotes aerobic glycolysis and transformation of human nasopharyngeal epithelial cells.

    PubMed

    Lo, Angela Kwok-Fung; Dawson, Christopher W; Young, Lawrence S; Ko, Chuen-Wai; Hau, Pok-Man; Lo, Kwok-Wai

    2015-10-01

    Non-keratinizing nasopharyngeal carcinoma (NPC) is closely associated with Epstein-Barr virus (EBV) infection. The EBV-encoded latent membrane protein 1 (LMP1) is believed to play an important role in NPC pathogenesis by virtue of its ability to activate multiple cell signalling pathways which collectively promote cell proliferation, transformation, angiogenesis, and invasiveness, as well as modulation of energy metabolism. In this study, we report that LMP1 increases cellular uptake of glucose and glutamine, enhances LDHA activity and lactate production, but reduces pyruvate kinase activity and pyruvate concentrations. LMP1 also increases the phosphorylation of PKM2, LDHA, and FGFR1, as well as the expression of PDHK1, FGFR1, c-Myc, and HIF-1α, regardless of oxygen availability. Collectively, these findings suggest that LMP1 promotes aerobic glycolysis. With respect to FGFR1 signalling, LMP1 not only increases FGFR1 expression, but also up-regulates FGF2, leading to constitutive activation of the FGFR1 signalling pathway. Furthermore, two inhibitors of FGFR1 (PD161570 and SU5402) attenuate LMP1-mediated aerobic glycolysis, cellular transformation (proliferation and anchorage-independent growth), cell migration, and invasion in nasopharyngeal epithelial cells, identifying FGFR1 signalling as a key pathway in LMP1-mediated growth transformation. Immunohistochemical staining revealed that high levels of phosphorylated FGFR1 are common in primary NPC specimens and that this correlated with the expression of LMP1. In addition, FGFR1 inhibitors suppress cell proliferation and anchorage-independent growth of NPC cells. Our current findings demonstrate that LMP1-mediated FGFR1 activation contributes to aerobic glycolysis and transformation of epithelial cells, thereby implicating FGF2/FGFR1 signalling activation in the EBV-driven pathogenesis of NPC.

  14. Inactivation of the Kluyveromyces lactis KlPDA1 gene leads to loss of pyruvate dehydrogenase activity, impairs growth on glucose and triggers aerobic alcoholic fermentation.

    PubMed

    Zeeman, A M; Luttik, M A; Thiele, C; van Dijken, J P; Pronk, J T; Steensma, H Y

    1998-12-01

    The KlPDA1 gene, encoding the E1alpha subunit of the mitochondrial pyruvate-dehydrogenase (PDH) complex was isolated from a Kluyveromyces lactis genomic library by screening with a 1.1 kb internal fragment of the Saccharomyces cerevisiae PDA1 gene. The predicted amino acid sequence encoded by KlPDA1 showed 87% similarity and 79% identity to its S. cerevisiae counterpart. Disruption of KIPDA1 resulted in complete absence of PDH activity in cell extracts. The maximum specific growth rate on glucose of null mutants was 3.5-fold lower than that of the wild-type, whereas growth on ethanol was unaffected. Wild-type K. lactis CBS 2359 exhibits a Crabtree-negative phenotype, i.e. no ethanol was produced in aerobic batch cultures grown on glucose. In contrast, substantial amounts of ethanol and acetaldehyde were produced in aerobic cultures of an isogenic Klpda1 null mutant. A wild-type specific growth rate was restored after introduction of an intact KlPDA1 gene but not, as previously found for S. cerevisiae pda1 mutants, by cultivation in the presence of leucine. The occurrence of aerobic fermentation and slow growth of the Klpda1 null mutant indicate that, although present, the enzymes of the PDH bypass (pyruvate decarboxylase, acetaldehyde dehydrogenase and acetyl-CoA synthetase) could not efficiently replace the PDH complex during batch cultivation on glucose. Only at relatively low growth rates (D = 0.10 h(-1)) in aerobic, glucose-limited chemostat cultures, could the PDH bypass completely replace the PDH complex, thus allowing fully respiratory growth. This resulted in a lower biomass yield [g biomass (g glucose)-1] than in the wild-type due to a higher consumption of ATP in the PDH bypass compared to the formation of acetyl-CoA via the PDH complex.

  15. Metaproteomic Identification of Diazotrophic Methanotrophs and Their Localization in Root Tissues of Field-Grown Rice Plants

    PubMed Central

    Bao, Zhihua; Okubo, Takashi; Kubota, Kengo; Kasahara, Yasuhiro; Tsurumaru, Hirohito; Anda, Mizue; Ikeda, Seishi

    2014-01-01

    In a previous study by our group, CH4 oxidation and N2 fixation were simultaneously activated in the roots of wild-type rice plants in a paddy field with no N input; both processes are likely controlled by a rice gene for microbial symbiosis. The present study examined which microorganisms in rice roots were responsible for CH4 oxidation and N2 fixation under the field conditions. Metaproteomic analysis of root-associated bacteria from field-grown rice (Oryza sativa Nipponbare) revealed that nitrogenase complex-containing nitrogenase reductase (NifH) and the alpha subunit (NifD) and beta subunit (NifK) of dinitrogenase were mainly derived from type II methanotrophic bacteria of the family Methylocystaceae, including Methylosinus spp. Minor nitrogenase proteins such as Methylocella, Bradyrhizobium, Rhodopseudomonas, and Anaeromyxobacter were also detected. Methane monooxygenase proteins (PmoCBA and MmoXYZCBG) were detected in the same bacterial group of the Methylocystaceae. Because these results indicated that Methylocystaceae members mediate both CH4 oxidation and N2 fixation, we examined their localization in rice tissues by using catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). The methanotrophs were localized around the epidermal cells and vascular cylinder in the root tissues of the field-grown rice plants. Our metaproteomics and CARD-FISH results suggest that CH4 oxidation and N2 fixation are performed mainly by type II methanotrophs of the Methylocystaceae, including Methylosinus spp., inhabiting the vascular bundles and epidermal cells of rice roots. PMID:24928870

  16. Biological conversion of biogas to methanol using methanotrophs isolated from solid-state anaerobic digestate.

    PubMed

    Sheets, Johnathon P; Ge, Xumeng; Li, Yueh-Fen; Yu, Zhongtang; Li, Yebo

    2016-02-01

    The aim of this work was to isolate methanotrophs (methane oxidizing bacteria) that can directly convert biogas produced at a commercial anaerobic digestion (AD) facility to methanol. A methanotrophic bacterium was isolated from solid-state anaerobic digestate. The isolate had characteristics comparable to obligate methanotrophs from the genus Methylocaldum. This newly isolated methanotroph grew on biogas or purified CH4 and successfully converted biogas from AD to methanol. Methanol production was achieved using several methanol dehydrogenase (MDH) inhibitors and formate as an electron donor. The isolate also produced methanol using phosphate with no electron donor or using formate with no MDH inhibitor. The maximum methanol concentration (0.43±0.00gL(-1)) and 48-h CH4 to methanol conversion (25.5±1.1%) were achieved using biogas as substrate and a growth medium containing 50mM phosphate and 80mM formate.

  17. 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

  18. In vitro and in vivo study of epigallocatechin-3-gallate-induced apoptosis in aerobic glycolytic hepatocellular carcinoma cells involving inhibition of phosphofructokinase activity

    PubMed Central

    Li, Sainan; Wu, Liwei; Feng, Jiao; Li, Jingjing; Liu, Tong; Zhang, Rong; Xu, Shizan; Cheng, Keran; Zhou, Yuqing; Zhou, Shunfeng; Kong, Rui; Chen, Kan; Wang, Fan; Xia, Yujing; Lu, Jie; Zhou, Yingqun; Dai, Weiqi; Guo, Chuanyong

    2016-01-01

    Glycolysis, as an altered cancer cell-intrinsic metabolism, is an essential hallmark of cancer. Phosphofructokinase (PFK) is a metabolic sensor in the glycolytic pathway, and restricting the substrate availability for this enzyme has been researched extensively as a target for chemotherapy. In the present study, we investigated that the effects of epigallocatechin-3-gallate (EGCG), an active component of green tea, on inhibiting cell growth and inducing apoptosis by promoting a metabolic shift away from glycolysis in aerobic glycolytic hepatocellular carcinoma (HCC) cells. EGCG modulated the oligomeric structure of PFK, potentially leading to metabolic stress associated apoptosis and suggesting that EGCG acts by directly suppressing PFK activity. A PFK activity inhibitor enhanced the effect, while the allosteric activator reversed EGCG-induced HCC cell death. PFK siRNA knockdown-induced apoptosis was not reversed by the activator. EGCG enhanced the effect of sorafenib on cell growth inhibition in both aerobic glycolytic HCC cells and in a xenograft mouse model. The present study suggests a potential role for EGCG as an adjuvant in cancer therapy, which merits further investigation at the clinical level. PMID:27349173

  19. Algebra Aerobics

    ERIC Educational Resources Information Center

    Barnes, Julie; Jaqua, Kathy

    2011-01-01

    A kinesthetic approach to developing ideas of function transformations can get students physically and intellectually involved. This article presents low- or no-cost activities which use kinesthetics to support high school students' mathematical understanding of transformations of function graphs. The important point of these activities is to help…

  20. Microbial decolorization of reactive black-5 in a two-stage anaerobic-aerobic reactor using acclimatized activated textile sludge.

    PubMed

    Mohanty, Sagarika; Dafale, Nishant; Rao, Nageswara Neti

    2006-10-01

    A two-stage anaerobic-aerobic treatment process based on mixed culture of bacteria isolated from textile dye effluent was used to degrade reactive black 5 dye (RB-5). The anaerobic step was studied in more detail by varying the dye concentration from 100 to 3000 mg l(-1). The results showed that major decolorization was achieved during the anaerobic process. The time required for decolorization by > 90% increased as the concentration of the dye increased. It was also found that maintaining dissolved oxygen (DO) concentration below 0.5 mg l(-1 )and addition of a co-substrate viz., glucose, facilitates anaerobic decolorization reaction remarkably. An attempt was made to identify the metabolites formed in anaerobic process by using high performance liquid chromatography (HPLC) and UV-VIS spectrophotometry. A plate assay was performed for the detection of dominant decolorizing bacteria. Only a few bacterial colonies with high clearing zones (decolorization zones) were found. The results showed that under anaerobic condition RB-5 molecules were reduced and aromatic amines were generated. The aromatic amine metabolite was partly removed in subsequent aerobic bio-treatment. It was possible to achieve more than 90% decolorization and approximately 46% reduction in amine metabolite concentration through two-stage anaerobic-aerobic treatment after a reaction period of 2 days.

  1. Conditioning and Aerobics for Older Americans.

    ERIC Educational Resources Information Center

    Hansen, Joyce

    1980-01-01

    A class designed for the maintenance and gradual improvement of senior citizens' physical fitness includes relaxation training, flexibility and stretching exercises, interval training activities (designed as a link between less strenuous exercise and more strenuous activities), and aerobic exercises. (CJ)

  2. Aging well: methanotrophic potential and community structure along a paddy soil chronosequence of 2000 years.

    NASA Astrophysics Data System (ADS)

    Ho, Adrian; Frenzel, Peter

    2010-05-01

    Given that rice paddies are anthropogenic methane sources and the inevitable need to increase rice production to sustain human population growth, it is pertinent to identify the effects of long term agriculture on the selection of methanotrophs. Methanotrophs play a crucial role in mitigating methane emission from rice paddies. Therefore, we analyzed the methanotroph community along a chronosequence of paddy soils from China covering recently reclaimed sites to paddies under permanent agriculture since 2000 years (Cheng et al., 2009; doi:10.1016/j.geoderma.2009.03.016). Maximum potential methane oxidation rate (PMOR) increased monotonically with age. Our results also showed that long-term agriculture imposes a selection pressure on different groups of methanotrophs. In contrast to younger soils, type Ib methanotrophs were observed to multiply in correspondence with increasing PMOR in ancient soils, while other groups showed a relatively stable community composition as revealed by pmoA-based fingerprints (T-RFLP) and quantitative PCR. Cloning and sequencing the pmoA (a key gene in methane oxidation), the soils were found to harbour known and putative methanotrophs, ammonium-oxidizing bacteria, and interestingly, sequences affiliated to Crenothrix, a methane oxidizer with an unusual pmoA (Stoecker et al., 2006; doi:10.1073/pnas.0506361103). In summary, long-term agriculture shapes the community and allows for an elevated level of potential methane oxidation.

  3. Preparation and catalytic activity of poly(N-vinyl-2-pyrrolidone)-protected Au nanoparticles for the aerobic oxidation of glucose.

    PubMed

    Zhang, Haijun; Li, Wenqi; Gu, Yajun; Zhang, Shaowei

    2014-08-01

    PVP-protected Au nanoparticles (NPs) for the aerobic oxidation of glucose were prepared by using NaBH4 reduction method. The effects of processing parameters such as Au3+ ion concentration, reaction temperature, ratio of NaBH4 or PVP to Au3+, and solvent composition on their particle sizes and catalytic activities were studied in detail and the synthesis conditions optimized. As-prepared Au NPs possessed a FCC structure, with an average size varying from about 100 to 2.6 nm depending on their preparation conditions. The size changes affected their catalytic activities in the aerobic oxidation of glucose. The Au NPs with the average size of 2.6 nm prepared under the optimal conditions showed a high instantaneous catalytic activity as well as a high long-time stability. Based on the kinetic study on the glucose oxidation over the PVP-protected Au NPs, the corresponding apparent activation energy was determined as 82 kJ mol(-1).

  4. Seasonal Variation in Abundance and Diversity of Bacterial Methanotrophs in Five Temperate Lakes.

    PubMed

    Samad, Md Sainur; Bertilsson, Stefan

    2017-01-01

    Lakes are significant sources of methane (CH4) to the atmosphere. Within these systems, methanotrophs consume CH4 and act as a potential biofilter mitigating the emission of this potent greenhouse gas. However, it is still not well understood how spatial and temporal variation in environmental parameters influence the abundance, diversity, and community structure of methanotrophs in lakes. To address this gap in knowledge, we collected water samples from three depths (surface, middle, and bottom) representing oxic to suboxic or anoxic zones of five different Swedish lakes in winter (ice-covered) and summer. Methanotroph abundance was determined by quantitative real time polymerase chain reaction and a comparison to environmental variables showed that temperature, season as well as depth, phosphate concentration, dissolved oxygen, and CH4 explained the observed variation in methanotroph abundance. Due to minimal differences in methane concentrations (0.19 and 0.29 μM for summer and winter, respectively), only a weak and even negative correlation was observed between CH4 and methanotrophs, which was possibly due to usage of CH4. Methanotrophs were present at concentrations ranging from 10(5) to 10(6) copies/l throughout the oxic (surface) and suboxic/anoxic (bottom) water mass of the lakes, but always contributed less than 1.3% to the total microbial community. Relative methanotroph abundance was significantly higher in winter than in summer and consistently increased with depth in the lakes. Phylogenetic analysis of pmoA genes in two clone libraries from two of the ice-covered lakes (Ekoln and Ramsen) separated the methanotrophs into five distinct clusters of Methylobacter sp. (Type I). Terminal restriction fragment length polymorphism analysis of the pmoA gene further revealed significant differences in methanotrophic communities between lakes as well as between winter and summer while there were no significant differences between water layers. The study provides

  5. Seasonal Variation in Abundance and Diversity of Bacterial Methanotrophs in Five Temperate Lakes

    PubMed Central

    Samad, Md Sainur; Bertilsson, Stefan

    2017-01-01

    Lakes are significant sources of methane (CH4) to the atmosphere. Within these systems, methanotrophs consume CH4 and act as a potential biofilter mitigating the emission of this potent greenhouse gas. However, it is still not well understood how spatial and temporal variation in environmental parameters influence the abundance, diversity, and community structure of methanotrophs in lakes. To address this gap in knowledge, we collected water samples from three depths (surface, middle, and bottom) representing oxic to suboxic or anoxic zones of five different Swedish lakes in winter (ice-covered) and summer. Methanotroph abundance was determined by quantitative real time polymerase chain reaction and a comparison to environmental variables showed that temperature, season as well as depth, phosphate concentration, dissolved oxygen, and CH4 explained the observed variation in methanotroph abundance. Due to minimal differences in methane concentrations (0.19 and 0.29 μM for summer and winter, respectively), only a weak and even negative correlation was observed between CH4 and methanotrophs, which was possibly due to usage of CH4. Methanotrophs were present at concentrations ranging from 105 to 106 copies/l throughout the oxic (surface) and suboxic/anoxic (bottom) water mass of the lakes, but always contributed less than 1.3% to the total microbial community. Relative methanotroph abundance was significantly higher in winter than in summer and consistently increased with depth in the lakes. Phylogenetic analysis of pmoA genes in two clone libraries from two of the ice-covered lakes (Ekoln and Ramsen) separated the methanotrophs into five distinct clusters of Methylobacter sp. (Type I). Terminal restriction fragment length polymorphism analysis of the pmoA gene further revealed significant differences in methanotrophic communities between lakes as well as between winter and summer while there were no significant differences between water layers. The study provides new

  6. Diversity and distribution of methanotrophic archaea at cold seeps.

    PubMed

    Knittel, Katrin; Lösekann, Tina; Boetius, Antje; Kort, Renate; Amann, Rudolf

    2005-01-01

    In this study we investigated by using 16S rRNA-based methods the distribution and biomass of archaea in samples from (i) sediments above outcropping methane hydrate at Hydrate Ridge (Cascadia margin off Oregon) and (ii) massive microbial mats enclosing carbonate reefs (Crimea area, Black Sea). The archaeal diversity was low in both locations; there were only four (Hydrate Ridge) and five (Black Sea) different phylogenetic clusters of sequences, most of which belonged to the methanotrophic archaea (ANME). ANME group 2 (ANME-2) sequences were the most abundant and diverse sequences at Hydrate Ridge, whereas ANME-1 sequences dominated the Black Sea mats. Other seep-specific sequences belonged to the newly defined group ANME-3 (related to Methanococcoides spp.) and to the Crenarchaeota of marine benthic group B. Quantitative analysis of the samples by fluorescence in situ hybridization (FISH) showed that ANME-1 and ANME-2 co-occurred at the cold seep sites investigated. At Hydrate Ridge the surface sediments were dominated by aggregates consisting of ANME-2 and members of the Desulfosarcina-Desulfococcus branch (DSS) (ANME-2/DSS aggregates), which accounted for >90% of the total cell biomass. The numbers of ANME-1 cells increased strongly with depth; these cells accounted 1% of all single cells at the surface and more than 30% of all single cells (5% of the total cells) in 7- to 10-cm sediment horizons that were directly above layers of gas hydrate. In the Black Sea microbial mats ANME-1 accounted for about 50% of all cells. ANME-2/DSS aggregates occurred in microenvironments within the mat but accounted for only 1% of the total cells. FISH probes for the ANME-2a and ANME-2c subclusters were designed based on a comparative 16S rRNA analysis. In Hydrate Ridge sediments ANME-2a/DSS and ANME-2c/DSS aggregates differed significantly in morphology and abundance. The relative abundance values for these subgroups were remarkably different at Beggiatoa sites (80% ANME-2a, 20

  7. Distribution and diversity of Verrucomicrobia methanotrophs in geothermal and acidic environments.

    PubMed

    Sharp, Christine E; Smirnova, Angela V; Graham, Jaime M; Stott, Matthew B; Khadka, Roshan; Moore, Tim R; Grasby, Stephen E; Strack, Maria; Dunfield, Peter F

    2014-06-01

    Recently, methanotrophic members of the phylum Verrucomicrobia have been described, but little is known about their distribution in nature. We surveyed methanotrophic bacteria in geothermal springs and acidic wetlands via pyrosequencing of 16S rRNA gene amplicons. Putative methanotrophic Verrucomicrobia were found in samples covering a broad temperature range (22.5-81.6°C), but only in acidic conditions (pH 1.8-5.0) and only in geothermal environments, not in acidic bogs or fens. Phylogenetically, three 16S rRNA gene sequence clusters of putative methanotrophic Verrucomicrobia were observed. Those detected in high-temperature geothermal samples (44.1-81.6°C) grouped with known thermoacidiphilic 'Methylacidiphilum' isolates. A second group dominated in moderate-temperature geothermal samples (22.5-40.1°C) and a representative mesophilic methanotroph from this group was isolated (strain LP2A). Genome sequencing verified that strain LP2A possessed particulate methane monooxygenase, but its 16S rRNA gene sequence identity to 'Methylacidiphilum infernorum' strain V4 was only 90.6%. A third group clustered distantly with known methanotrophic Verrucomicrobia. Using pmoA-gene targeted quantitative polymerase chain reaction, two geothermal soil profiles showed a dominance of LP2A-like pmoA sequences in the cooler surface layers and 'Methylacidiphilum'-like pmoA sequences in deeper, hotter layers. Based on these results, there appears to be a thermophilic group and a mesophilic group of methanotrophic Verrucomicrobia. However, both were detected only in acidic geothermal environments.

  8. Aerobic rice mechanization: techniques for crop establishment

    NASA Astrophysics Data System (ADS)

    Khusairy, K. M.; Ayob, H.; Chan, C. S.; Fauzi, M. I. Mohamed; Mohamad Fakhrul, Z. O.; Shahril Shah, G. S. M.; Azlan, O.; Rasad, M. A.; Hashim, A. M.; Arshad, Z.; E, E. Ibrahim; Saifulizan, M. N.

    2015-12-01

    Rice being the staple food crops, hundreds of land races in it makes the diversity of rice crops. Aerobic rice production was introduced which requires much less water input to safeguard and sustain the rice production and conserve water due to decreasing water resources, climatic changes and competition from urban and industrial users. Mechanization system plays an important role for the success of aerobic rice cultivation. All farming activities for aerobic rice production are run on aerobic soil conditions. Row seeder mechanization system is developed to replace conventional seeding technique on the aerobic rice field. It is targeted for small and the large scale aerobic rice farmers. The aero - seeder machine is used for the small scale aerobic rice field, while the accord - seeder is used for the large scale aerobic rice field. The use of this mechanization machine can eliminate the tedious and inaccurate seeding operations reduce labour costs and increases work rate. The machine is easy to operate and it can increase crop establishment rate. It reduce missing hill, increasing planting and crop with high yield can be produce. This machine is designed for low costs maintenance and it is easy to dismantle and assemble during maintenance and it is safe to be used.

  9. Methanotrophic symbionts provide carbon for photosynthesis in peat bogs.

    PubMed

    Raghoebarsing, Ashna A; Smolders, Alfons J P; Schmid, Markus C; Rijpstra, W Irene C; Wolters-Arts, Mieke; Derksen, Jan; Jetten, Mike S M; Schouten, Stefan; Sinninghe Damsté, Jaap S; Lamers, Leon P M; Roelofs, Jan G M; Op den Camp, Huub J M; Strous, Marc

    2005-08-25

    Wetlands are the largest natural source of atmospheric methane, the second most important greenhouse gas. Methane flux to the atmosphere depends strongly on the climate; however, by far the largest part of the methane formed in wetland ecosystems is recycled and does not reach the atmosphere. The biogeochemical controls on the efficient oxidation of methane are still poorly understood. Here we show that submerged Sphagnum mosses, the dominant plants in some of these habitats, consume methane through symbiosis with partly endophytic methanotrophic bacteria, leading to highly effective in situ methane recycling. Molecular probes revealed the presence of the bacteria in the hyaline cells of the plant and on stem leaves. Incubation with (13)C-methane showed rapid in situ oxidation by these bacteria to carbon dioxide, which was subsequently fixed by Sphagnum, as shown by incorporation of (13)C-methane into plant sterols. In this way, methane acts as a significant (10-15%) carbon source for Sphagnum. The symbiosis explains both the efficient recycling of methane and the high organic carbon burial in these wetland ecosystems.

  10. Aerobic Production and Utilization of Lactate Satisfy Increased Energy Demands Upon Neuronal Activation in Hippocampal Slices and Provide Neuroprotection Against Oxidative Stress

    PubMed Central

    Schurr, Avital; Gozal, Evelyne

    2012-01-01

    Ever since it was shown for the first time that lactate can support neuronal function in vitro as a sole oxidative energy substrate, investigators in the field of neuroenergetics have been debating the role, if any, of this glycolytic product in cerebral energy metabolism. Our experiments employed the rat hippocampal slice preparation with electrophysiological and biochemical methodologies. The data generated by these experiments (a) support the hypothesis that lactate, not pyruvate, is the end-product of cerebral aerobic glycolysis; (b) indicate that lactate plays a major and crucial role in affording neural tissue to respond adequately to glutamate excitation and to recover unscathed post-excitation; (c) suggest that neural tissue activation is accompanied by aerobic lactate and NADH production, the latter being produced when the former is converted to pyruvate by mitochondrial lactate dehydrogenase (mLDH); (d) imply that NADH can be utilized as an endogenous scavenger of reactive oxygen species (ROS) to provide neuroprotection against ROS-induced neuronal damage. PMID:22275901

  11. Novel Methanotrophs of the Family Methylococcaceae from Different Geographical Regions and Habitats

    PubMed Central

    Islam, Tajul; Larsen, Øivind; Torsvik, Vigdis; Øvreås, Lise; Panosyan, Hovik; Murrell, J. Colin; Birkeland, Nils-Kåre; Bodrossy, Levente

    2015-01-01

    Terrestrial methane seeps and rice paddy fields are important ecosystems in the methane cycle. Methanotrophic bacteria in these ecosystems play a key role in reducing methane emission into the atmosphere. Here, we describe three novel methanotrophs, designated BRS-K6, GFS-K6 and AK-K6, which were recovered from three different habitats in contrasting geographic regions and ecosystems: waterlogged rice-field soil and methane seep pond sediments from Bangladesh; and warm spring sediments from Armenia. All isolates had a temperature range for growth of 8–35 °C (optimal 25–28 °C) and a pH range of 5.0–7.5 (optimal 6.4–7.0). 16S rRNA gene sequences showed that they were new gammaproteobacterial methanotrophs, which form a separate clade in the family Methylococcaceae. They fell into a cluster with thermotolerant and mesophilic growth tendency, comprising the genera Methylocaldum-Methylococcus-Methyloparacoccus-Methylogaea. So far, growth below 15 °C of methanotrophs from this cluster has not been reported. The strains possessed type I intracytoplasmic membranes. The genes pmoA, mxaF, cbbL, nifH were detected, but no mmoX gene was found. Each strain probably represents a novel species either belonging to the same novel genus or each may even represent separate genera. These isolates extend our knowledge of methanotrophic Gammaproteobacteria and their physiology and adaptation to different ecosystems. PMID:27682101

  12. Aerobic Excercise and Research Opportunities to Benefit Impaired Children. (Project AEROBIC). Final Report.

    ERIC Educational Resources Information Center

    Idaho Univ., Moscow.

    The final report summarizes accomplishments of Project AEROBIC (Aerobic Exercise and Research Opportunities to Benefit Impaired Children), which provided a physical education exercise program for severely, profoundly, and multiply handicapped children aged 10-21. Activities are outlined for the 3 year period and include modification of exercise…

  13. Effect of long term anaerobic and intermittent anaerobic/aerobic starvation on aerobic granules.

    PubMed

    Pijuan, Maite; Werner, Ursula; Yuan, Zhiguo

    2009-08-01

    The effect of long term anaerobic and intermittent anaerobic/aerobic starvation on the structure and activity of aerobic granules was studied. Aerobic granular sludge treating abattoir wastewater and achieving high levels of nutrient removal was subjected to 4-5 week starvation under anaerobic and intermittent anaerobic/aerobic conditions. Microscopic pictures of granules at the beginning of the starvation period presented a round and compact surface morphology with a much defined external perimeter. Under both starvation conditions, the morphology changed at the end of starvation with the external border of the granules surrounded by floppy materials. The loss of granular compactness was faster and more pronounced under anaerobic/aerobic starvation conditions. The release of Ca(2+) at the onset of anaerobic/aerobic starvation suggests a degradation of extracellular polymeric substances. The activity of ammonia oxidizing bacteria was reduced by 20 and 36% during anaerobic and intermittent anaerobic/aerobic starvation, respectively. When fresh wastewater was reintroduced, the granules recovered their initial morphology within 1 week of normal operation and the nutrient removal activity recovered fully in 3 weeks. The results show that both anaerobic and intermittent anaerobic/aerobic conditions are suitable for maintaining granule structure and activity during starvation.

  14. WWC Review of the Report "A Randomized Trial Examining the Effects of Aerobic Physical Activity on Attention-Deficit/Hyperactivity Disorder Symptoms in Young Children." What Works Clearinghouse Single Study Review

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2015

    2015-01-01

    For the 2014 study, "A Randomized Trial Examining the Effects of Aerobic Physical Activity on Attention-Deficit/Hyperactivity Disorder Symptoms in Young Children", researchers examined the effect of a daily before-school physical activity program on behavioral outcomes of students in grades K-2. The study sample included 202 students who…

  15. The Bacteriohopanepolyol Inventory of Novel Aerobic Methane Oxidising Bacteria Reveals New Biomarker Signatures of Aerobic Methanotrophy in Marine Systems.

    PubMed

    Rush, Darci; Osborne, Kate A; Birgel, Daniel; Kappler, Andreas; Hirayama, Hisako; Peckmann, Jörn; Poulton, Simon W; Nickel, Julia C; Mangelsdorf, Kai; Kalyuzhnaya, Marina; Sidgwick, Frances R; Talbot, Helen M

    2016-01-01

    Aerobic methane oxidation (AMO) is one of the primary biologic pathways regulating the amount of methane (CH4) released into the environment. AMO acts as a sink of CH4, converting it into carbon dioxide before it reaches the atmosphere. It is of interest for (paleo)climate and carbon cycling studies to identify lipid biomarkers that can be used to trace AMO events, especially at times when the role of methane in the carbon cycle was more pronounced than today. AMO bacteria are known to synthesise bacteriohopanepolyol (BHP) lipids. Preliminary evidence pointed towards 35-aminobacteriohopane-30,31,32,33,34-pentol (aminopentol) being a characteristic biomarker for Type I methanotrophs. Here, the BHP compositions were examined for species of the recently described novel Type I methanotroph bacterial genera Methylomarinum and Methylomarinovum, as well as for a novel species of a Type I Methylomicrobium. Aminopentol was the most abundant BHP only in Methylomarinovum caldicuralii, while Methylomicrobium did not produce aminopentol at all. In addition to the expected regular aminotriol and aminotetrol BHPs, novel structures tentatively identified as methylcarbamate lipids related to C-35 amino-BHPs (MC-BHPs) were found to be synthesised in significant amounts by some AMO cultures. Subsequently, sediments and authigenic carbonates from methane-influenced marine environments were analysed. Most samples also did not contain significant amounts of aminopentol, indicating that aminopentol is not a useful biomarker for marine aerobic methanotophic bacteria. However, the BHP composition of the marine samples do point toward the novel MC-BHPs components being potential new biomarkers for AMO.

  16. The Bacteriohopanepolyol Inventory of Novel Aerobic Methane Oxidising Bacteria Reveals New Biomarker Signatures of Aerobic Methanotrophy in Marine Systems

    PubMed Central

    Birgel, Daniel; Kappler, Andreas; Hirayama, Hisako; Peckmann, Jörn; Poulton, Simon W.; Nickel, Julia C.; Mangelsdorf, Kai; Kalyuzhnaya, Marina; Sidgwick, Frances R.; Talbot, Helen M.

    2016-01-01

    Aerobic methane oxidation (AMO) is one of the primary biologic pathways regulating the amount of methane (CH4) released into the environment. AMO acts as a sink of CH4, converting it into carbon dioxide before it reaches the atmosphere. It is of interest for (paleo)climate and carbon cycling studies to identify lipid biomarkers that can be used to trace AMO events, especially at times when the role of methane in the carbon cycle was more pronounced than today. AMO bacteria are known to synthesise bacteriohopanepolyol (BHP) lipids. Preliminary evidence pointed towards 35-aminobacteriohopane-30,31,32,33,34-pentol (aminopentol) being a characteristic biomarker for Type I methanotrophs. Here, the BHP compositions were examined for species of the recently described novel Type I methanotroph bacterial genera Methylomarinum and Methylomarinovum, as well as for a novel species of a Type I Methylomicrobium. Aminopentol was the most abundant BHP only in Methylomarinovum caldicuralii, while Methylomicrobium did not produce aminopentol at all. In addition to the expected regular aminotriol and aminotetrol BHPs, novel structures tentatively identified as methylcarbamate lipids related to C-35 amino-BHPs (MC-BHPs) were found to be synthesised in significant amounts by some AMO cultures. Subsequently, sediments and authigenic carbonates from methane-influenced marine environments were analysed. Most samples also did not contain significant amounts of aminopentol, indicating that aminopentol is not a useful biomarker for marine aerobic methanotophic bacteria. However, the BHP composition of the marine samples do point toward the novel MC-BHPs components being potential new biomarkers for AMO. PMID:27824887

  17. Genomic insights into the metabolic potential and interactions between marine methanotrophic ANME archaea and associated bacteria

    NASA Astrophysics Data System (ADS)

    Orphan, V. J.; Skennerton, C.; Chadwick, G.; Haroon, F.; Tyson, G. W.; Leu, A.; Hatzenpichler, R.; Woyke, T.; Malmstrom, R.; Yu, H.; Scheller, S.

    2015-12-01

    Cooperative metabolic interactions between multiple groups of methanotrophic 'ANME' archaea and sulfate-reducing bacteria represent the primary sink for methane within continental margin sediments. These syntrophic associations are frequently observed as structured multi-celled consortia in methane seeps, often comprising a substantial proportion of the microbial biomass within near seafloor seep sediments. Since their discovery nearly 15 years ago, a number of distinct ANME groups and multiple sulfate-reducing bacterial partners have been described from seep environments worldwide. Attempts to reconstruct the genomes of some ANME organisms have been reported, however the ecological physiology and metabolic interactions of distinct ANME lineages and their bacterial partners remains poorly understood. Here, we used a fluorescence azide-alkyne click chemistry technique known as BONCAT combined with FAC sorting to examine patterns in microbial membership and the genomes of single, metabolically active ANME-bacterial consortia recovered from methane seep sediments. This targeted consortia-level sequencing approach revealed significant diversity in the ANME-bacterial associations in situ as well as insights into the potential syntrophic mechanisms underpinning these enigmatic methane-fueled partnerships.

  18. Patterns of 15N assimilation and growth of methanotrophic ANME-2 archaea and sulfate-reducing bacteria within structured syntrophic consortia revealed by FISH-SIMS.

    PubMed

    Orphan, Victoria J; Turk, Kendra A; Green, Abigail M; House, Christopher H

    2009-07-01

    Methane release from the oceans is controlled in large part by syntrophic interactions between anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (DSS), frequently found as organized consortia. An understanding of the specifics of this symbiotic relationship and the metabolic heterogeneity existing between and within individual methane-oxidizing aggregates is currently lacking. Here, we use the microanalytical method FISH-SIMS (fluorescence in situ hybridization-secondary ion mass spectrometry) to describe the physiological traits and anabolic activity of individual methanotrophic consortia, specifically tracking (15)N-labelled protein synthesis to examine the effects of organization and size on the metabolic activity of the syntrophic partners. Patterns of (15)N distribution within individual aggregates showed enhanced (15)N assimilation in ANME-2 cells relative to the co-associated DSS revealing a decoupling in anabolic activity between the partners. Protein synthesis in ANME-2 cells was sustained throughout the core of individual ANME-2/DSS consortia ranging in size range from 4 to 20 μm. This indicates that metabolic activity of the methane-oxidizing archaea is not limited to, or noticeably enhanced at the ANME-2/DSS boundary. Overall, the metabolic activity of both syntrophic partners within consortia was greater than activity measured in representatives of the ANME-2 and DSS observed alone, with smaller ANME-2/DSS aggregates displaying a tendency for greater (15)N uptake and doubling times ranging from 3 to 5 months. The combination of (15)N-labelling and FISH-SIMS provides an important perspective on the extent of heterogeneity within methanotrophic aggregates and may aid in constraining predictive models of activity and growth by these syntrophic consortia.

  19. Oxidation of methane in biotrickling filters inoculated with methanotrophic bacteria.

    PubMed

    Cáceres, Manuel; Dorado, Antonio D; Gentina, Juan C; Aroca, Germán

    2016-07-01

    The oxidation of methane (CH4) using biofilters has been proposed as an alternative to mitigate anthropogenic greenhouse gas emissions with a low concentration of CH4 that cannot be used as a source of energy. However, conventional biofilters utilize organic packing materials that have a short lifespan, clogging problems, and are commonly inoculated with non-specific microorganisms leading to unpredictable CH4 elimination capacities (EC) and removal efficiencies (RE). The main objective of this work was to characterize the oxidation of CH4 in two biotrickling filters (BTFs) packed with polyethylene rings and inoculated with two methanotrophic bacteria, Methylomicrobium album and Methylocystis sp., in order to determine EC and CO2 production (pCO2) when using a specific inoculum. The repeatability of the results in both BTFs was determined when they operated at the same inlet load of CH4. A dynamic mathematical model that describes the CH4 abatement in the BTFs was developed and validated using mass transfer and kinetic parameters estimated independently. The results showed that EC and pCO2 of the BTFs are not identical but very similar for all the conditions tested. The use of specific inoculum has shown a faster startup and higher EC per unit area (0.019 gCH4 m(-2) h(-1)) in comparison to most of the previous studies at the same CH4 load rate (23.2 gCH4 m(-3) h(-1)). Global mass balance showed that the maximum reduction of CO2 equivalents was 98.5 gCO2eq m(-3) h(-1). The developed model satisfactorily described CH4 abatement in BTFs for a wide range of conditions.

  20. Gammaproteobacterial methanotrophs dominate cold methane seeps in floodplains of West Siberian rivers.

    PubMed

    Oshkin, Igor Y; Wegner, Carl-Eric; Lüke, Claudia; Glagolev, Mikhail V; Filippov, Illiya V; Pimenov, Nikolay V; Liesack, Werner; Dedysh, Svetlana N

    2014-10-01

    A complex system of muddy fluid-discharging and methane (CH4)-releasing seeps was discovered in a valley of the river Mukhrinskaya, one of the small rivers of the Irtysh Basin, West Siberia. CH4 flux from most (90%) of these gas ebullition sites did not exceed 1.45 g CH4 h(-1), while some seeps emitted up to 5.54 g CH4 h(-1). The δ(13)C value of methane released from these seeps varied between -71.1 and -71.3‰, suggesting its biogenic origin. Although the seeps were characterized by low in situ temperatures (3.5 to 5°C), relatively high rates of methane oxidation (15.5 to 15.9 nmol CH4 ml(-1) day(-1)) were measured in mud samples. Fluorescence in situ hybridization detected 10(7) methanotrophic bacteria (MB) per g of mud (dry weight), which accounted for up to 20.5% of total bacterial cell counts. Most (95.8 to 99.3%) methanotroph cells were type I (gammaproteobacterial) MB. The diversity of methanotrophs in this habitat was further assessed by pyrosequencing of pmoA genes, encoding particulate methane monooxygenase. A total of 53,828 pmoA gene sequences of seep-inhabiting methanotrophs were retrieved and analyzed. Nearly all of these sequences affiliated with type I MB, including the Methylobacter-Methylovulum-Methylosoma group, lake cluster 2, and several as-yet-uncharacterized methanotroph clades. Apparently, microbial communities attenuating methane fluxes from these local but strong CH4 sources in floodplains of high-latitude rivers have a large proportion of potentially novel, psychrotolerant methanotrophs, thereby providing a challenge for future isolation studies.

  1. A new intra-aerobic metabolism in the nitrite-dependent anaerobic methane-oxidizing bacterium Candidatus 'Methylomirabilis oxyfera'.

    PubMed

    Wu, Ming L; Ettwig, Katharina F; Jetten, Mike S M; Strous, Marc; Keltjens, Jan T; van Niftrik, Laura

    2011-01-01

    Biological methane oxidation proceeds either through aerobic or anaerobic pathways. The newly discovered bacterium Candidatus 'Methylomirabilis oxyfera' challenges this dichotomy. This bacterium performs anaerobic methane oxidation coupled to denitrification, but does so in a peculiar way. Instead of scavenging oxygen from the environment, like the aerobic methanotrophs, or driving methane oxidation by reverse methanogenesis, like the methanogenic archaea in sulfate-reducing systems, it produces its own supply of oxygen by metabolizing nitrite via nitric oxide into oxygen and dinitrogen gas. The intracellularly produced oxygen is then used for the oxidation of methane by the classical aerobic methane oxidation pathway involving methane mono-oxygenase. The present mini-review summarizes the current knowledge about this process and the micro-organism responsible for it.

  2. Treatment of high-strength synthetic sewage in a laboratory-scale upflow anaerobic sludge bed (UASB) with aerobic activated sludge (AS) post-treatment.

    PubMed

    Banihani, Qais H; Field, Jim A

    2013-01-01

    Performance of a combined system up-flow anaerobic sludge blanket (UASB) followed by aerobic treatment activated sludge (AS) for removal of carbonaceous and nitrogenous contaminants at an average temperature of 25°C was investigated. The combined system was fed with high strength synthetic sewage having chemical oxygen demand (COD) of 2500 mg L(-1). The organic loading rate (OLR) of the UASB reactor was increased gradually from 1.1 to 3.8 gCOD L(r) (-1) d(-1). At steady state condition, the UASB reactor achieved removal efficiency up to 83.5% of total COD (COD(tot)), 74.0% of volatile fatty acid (VFA) and 94.0% of protein. The combined system performed an excellent organic removal pushing the overall removal efficiency of COD(tot), VFA and protein to 91.0%, 99.9% and 98.2%, respectively. When the OLR of the UASB increased to 4.4 g COD L(r) (-1) d(-1), the UASB was overloaded and; thus, its effluent quality deteriorated. In respect to nitrogen removal, both partial nitrification and complete nitrification took place in aerobic post-treatment. When the dissolved oxygen (DO) concentration was >2.0 mg L(-1), complete nitrification (period B) occurred with an average nitrification efficiency of 96.2%. The partial nitrification occurred due to high OLR to AS during the overloading event (period A) and when DO concentration was <2.0 mg L(-1) (period C). The maximum accumulated nitrite concentration in periods A, B and C were 90.0, 0.9 and 75.8 mg NO(-) (2) -N L(-1), respectively. The nitrogen balance results of periods A and C indicated that there was a discrepancy between the amount of ammonium nitrogen removed and the amount of oxidized nitrogen formed. This suggests the occurrence of simultaneous nitrification/denitrification (SND) in aerobic post-treatment.

  3. The relationship of leg volume (muscle plus bone) to maximal aerobic power output on a bicycle ergometer: the effects of anaemia, malnutrition and physical activity.

    PubMed

    Davies, C T

    1974-01-01

    The relationship of maximal power output (VO2 max) to leg muscle plus bone) volume (LV) has been analysed in African children suffering from malnutrition and severe anaemia and in a group of rural adult Africans engaged in prolonged, active daily work. The results are examined in relation to 'normal' healthy active (but not in training) African ? s and ? s aged 7-35 years. The analysis clearly demonstrates that the association between VO2 max and LV is not causal; the effects of increased habitual activity and anaemia show that the two parameters can be varied independently. The effect of habitual activity on the VO2 max : LV relationship is essentially additive, whereas the effect of anaemia is multiplicative. However in malnutrition, the relationship remains unchanged; VO2 max decreases paripassu with the reduced leg (muscle plus bone) volume. Iron therapy produces an increase in VO2 max) towards normal values without a concomitant change in LV. The results give a clearer understanding of the relationship between 'active' muscle mass and aerobic power output on the bicycle ergometer and could be used as a basis for clinical diagnosis in the industrial and medical fields, particularly for cases of debilitating disease which have an effect on physiological performance and effort intolerance. The data at present cannot be applied to men and women over 35 years of age.

  4. Peer mentoring is associated with positive change in physical activity and aerobic fitness of grades 4, 5, and 6 students in the heart healthy kids program.

    PubMed

    Spencer, Rebecca A; Bower, Jenna; Kirk, Sara F L; Hancock Friesen, Camille

    2014-11-01

    Only 7% of Canadian children achieve activity recommendations, contributing to obesity and preventable disease. The Heart Healthy Kids (H2K) program was designed to test the relationship between peer mentoring, physical activity, and cardiovascular fitness. Participants from 10 schools (5 control, 5 intervention) were enrolled in the program. In control schools, H2K included a physical activity challenge and education sessions. Intervention schools included the addition of a peer-mentoring component. Physical activity was measured through daily pedometer recording. Cardiovascular fitness was evaluated using the PACER (Progressive Aerobic Cardiovascular Endurance Run) protocol to calculate maximal oxygen uptake (VO2 max). Participants included 808 children (average age 9.9 ± 1.0 years). Although control and intervention schools did not differ at baseline, participants with peer mentoring logged significantly more steps per school day, on average, than those in control schools (6,785 ± 3,011 vs. 5,630 ± 2,586; p < .001). Male participants logged significantly more steps per school day than female participants. A significant improvement in VO2 max was also noted in intervention schools, with an average increase of 1.72 ml/mg/min. H2K was associated with positive change in physical activity and cardiovascular fitness, suggesting that peer mentoring shows promise for application in health promotion interventions.

  5. Methylocystis bryophila sp. nov., a facultatively methanotrophic bacterium from acidic Sphagnum peat, and emended description of the genus Methylocystis (ex Whittenbury et al. 1970) Bowman et al. 1993.

    PubMed

    Belova, Svetlana E; Kulichevskaya, Irina S; Bodelier, Paul L E; Dedysh, Svetlana N

    2013-03-01

    A novel species is proposed for two facultatively methanotrophic representatives of the genus Methylocystis, strains H2s(T) and S284, which were isolated from an acidic (pH 4.3) Sphagnum peat-bog lake (Teufelssee, Germany) and an acidic (pH 3.8) peat bog (European North Russia), respectively. Cells of strains H2s(T) and S284 are aerobic, Gram-negative, non-motile, curved coccoids or short rods that contain an intracytoplasmic membrane system typical of type-II methanotrophs. They possess both a soluble and a particulate methane monooxygenase (MMO); the latter is represented by two isozymes, pMMO1 and pMMO2. The preferred growth substrates are methane and methanol. In the absence of C1 substrates, however, these methanotrophs are capable of slow growth on acetate. Atmospheric nitrogen is fixed by means of an aerotolerant nitrogenase. Strains H2s(T) and S284 grow between pH 4.2 and 7.6 (optimum pH 6.0-6.5) and at 8-37 °C (optimum 25-30 °C). The major fatty acids are C18 : 1ω8c, C18 : 1ω7c and C16 : 1ω7c; the major quinone is Q-8. The DNA G+C content is 62.0-62.3 mol%. Strains H2s(T) and S284 share identical 16S rRNA gene sequences, which displayed 96.6-97.3 % similarity to sequences of other taxonomically characterized members of the genus Methylocystis. Therefore, strains H2s(T) and S284 are classified as members of a novel species, for which the name Methylocystis bryophila sp. nov. is proposed; strain H2s(T) ( = DSM 21852(T)  = VKM B-2545(T)) is the type strain.

  6. Activity profile and physiological requirements of junior elite basketball players in relation to aerobic-anaerobic fitness.

    PubMed

    Ben Abdelkrim, Nidhal; Castagna, Carlo; Jabri, Imed; Battikh, Tahar; El Fazaa, Saloua; El Ati, Jalila

    2010-09-01

    The aim of this research was to examine the demands of competitive basketball games and to study the relationship between athletes' physical capability and game performance. Physical and physiological game demands and the association of relevant field test with game performance were examined in 18 male junior basketball players. Computerized time-motion analysis, heart rate (HR), and blood-lactate concentration [BL] measurements were performed during 6 basketball games. Players were also measured for explosive power, speed, agility, and maximal-strength and endurance performance. During the games, players covered 7,558 +/- 575 m, of which 1,743 +/- 317; 1,619 +/- 280; and 2,477 +/- 339 m were performed at high, moderate, and low intensities, respectively. The 19.3 +/- 3.5 and 56.0 +/- 6.3% of the playing time was spent above 95% and at 85-95% of maximal HR, respectively. Average and mean peak [BL] were 5.75 +/- 1.25 and 6.22 +/- 1.34 mmolxL, respectively. Distances covered at maximal- and high-speed running significantly (p < 0.01) decreased during the second half. Game maximal- and high-speed running were significantly correlated with endurance performance (r = 0.52, p < 0.05 and r = 0.49, p < 0.05, respectively). High-intensity shuffling distance resulted in being negatively related with agility (r = -0.68, p < 0.05). This study showed that basketball players experience fatigue as game time progresses and suggests the potential benefit of aerobic and agility conditioning in junior basketball.

  7. Aerobic and anaerobic methane oxidation in terrestrial mud volcanoes in the Northern Apennines

    NASA Astrophysics Data System (ADS)

    Wrede, C.; Brady, S.; Rockstroh, S.; Dreier, A.; Kokoschka, S.; Heinzelmann, S. M.; Heller, C.; Reitner, J.; Taviani, M.; Daniel, R.; Hoppert, M.

    2012-07-01

    Methane oxidizing prokaryotes are ubiquitous in oxic and anoxic habitats wherever C1-compounds are present. Thus, methane saturated mud volcano fluids should be a preferred habitat of methane consuming prokaryotes, using the readily available electron donors. In order to understand the relevance of methane as a carbon and energy source in mud volcano communities, we investigate the diversity of prokaryotic organisms involved in oxidation of methane in fluid samples from the Salse di Nirano mud volcano field situated in the Northern Apennines. Cell counts were at approximately 0.7 × 106 microbial cells/ml. A fraction of the microbial biomass was identified as ANME (anaerobic methanotroph) archaea by fluorescence in situ hybridization (FISH) analysis. They are associated in densely colonized flakes, of some tens of μm in diameter, embedded in a hyaline matrix. Diversity analysis based on the 16S rDNA genes, retrieved from amplified and cloned environmental DNA, revealed a high proportion of archaea, involved in anaerobic oxidation of methane (AOM). Aerobic methane-oxidizing proteobacteria could be highly enriched from mud volcano fluids, indicating the presence of aerobic methanotrophic bacteria, which may contribute to methane oxidation, whenever oxygen is readily available. The results imply that biofilms, dominated by ANME archaea, colonize parts of the mud volcano venting system.

  8. Response of aerobic granular sludge to the long-term presence to nanosilver in sequencing batch reactors: reactor performance, sludge property, microbial activity and community.

    PubMed

    Quan, Xiangchun; Cen, Yan; Lu, Fang; Gu, Lingyun; Ma, Jingyun

    2015-02-15

    The increasing use of silver nanoparticles (Ag NPs) raises concerns about their potential toxic effects on the environment. Granular shape sludge is a special type of microbial aggregate. The response of aerobic granular sludge (AGS) to the long-term presence of Ag NPs has not been well studied. In this study, AGS was exposed to 5 and 50mg/L Ag NPs in sequence batch reactors (SBRs) for 69 days, and its response was evaluated based on the sludge properties, microbial activity and community, and reactor performance. The results showed that Ag NPs caused inhibition to microbial activities of AGS from Day 35. At the end of 69 days of Ag NPs exposure, the microbial activity of AGS was significantly inhibited in terms of inhibitions of the ammonia oxidizing rate (33.0%), respiration rate (17.7% and 45.6%) and denitrification rate (6.8%), as well as decreases in the ammonia mono-oxygenase and nitrate reductase activities. During the long-term exposure, the AGS maintained its granular shape and large granule size (approximately 900 μm); the microbial community of AGS slightly changed, but the dominant microbial population remained. Overall, the AGS tolerated the toxicity of Ag NPs well, but a long-term exposure may produce chronic toxicity to the AGS, which is concerning.

  9. Aerobic microbial enhanced oil recovery

    SciTech Connect

    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 take place. Maximum efficiency was reached at low oxygen concentrations, approximately 1 mg O{sub 2}/liter.

  10. Neuromodulation of Aerobic Exercise—A Review

    PubMed Central

    Heijnen, Saskia; Hommel, Bernhard; Kibele, Armin; Colzato, Lorenza S.

    2016-01-01

    Running, and aerobic exercise in general, is a physical activity that increasingly many people engage in but that also has become popular as a topic for scientific research. Here we review the available studies investigating whether and to which degree aerobic exercise modulates hormones, amino acids, and neurotransmitters levels. In general, it seems that factors such as genes, gender, training status, and hormonal status need to be taken into account to gain a better understanding of the neuromodular underpinnings of aerobic exercise. More research using longitudinal studies and considering individual differences is necessary to determine actual benefits. We suggest that, in order to succeed, aerobic exercise programs should include optimal periodization, prevent overtraining and be tailored to interindividual differences, including neuro-developmental and genetically-based factors. PMID:26779053

  11. Aerobic Metabolism of Streptococcus agalactiae

    PubMed Central

    Mickelson, M. N.

    1967-01-01

    Streptococcus agalactiae cultures possess an aerobic pathway for glucose oxidation that is strongly inhibited by cyanide. The products of glucose oxidation by aerobically grown cells of S. agalactiae 50 are lactic and acetic acids, acetylmethylcarbinol, and carbon dioxide. Glucose degradation products by aerobically grown cells, as percentage of glucose carbon, were 52 to 61% lactic acid, 20 to 23% acetic acid, 5.5 to 6.5% acetylmethylcarbinol, and 14 to 16% carbon dioxide. There was no evidence for a pentose cycle or a tricarboxylic acid cycle. Crude cell-free extracts of S. agalactiae 50 possessed a strong reduced nicotinamide adenine dinucleotide (NADH2) oxidase that is also cyanide-sensitive. Dialysis or ultrafiltration of the crude, cell-free extract resulted in loss of NADH2 oxidase activity. Oxidase activity was restored to the inactive extract by addition of the ultrafiltrate or by addition of menadione or K3Fe(CN)6. Noncytochrome iron-containing pigments were present in cell-free extracts of S. agalactiae. The possible participation of these pigments in the respiration of S. agalactiae is presently being studied. PMID:4291090

  12. Soluble methane monooxygenase gene clusters from trichloroethylene-degrading Methylomonas sp. strains and detection of methanotrophs during in situ bioremediation

    SciTech Connect

    Shigematsu, Toru; Hanada, Satoshi; Eguchi, Masahiro; Kamagata, Yoichi; Kanagawa, Takahiro; Kurane; Ryuichiro

    1999-12-01

    The soluble MMO (sMMO) gene clusters from group 1 methanotrophs were characterized. An 9.1-kb KpmI fragment from Methylomonas sp. strain KSWIII and a 7.5-kb SalI fragment from methylomonas sp. strain KSPIII which contained the sMMO gene clusters were cloned and sequenced. The sequences of these two fragments were almost identical. The sMMO gene clusters in the fragment consisted of six open reading frames which were 52 to 79% similar to the corresponding genes of previously described sMMO gene clusters of the group 2 and group 10 methanotrophs. The phylogenetic analysis of the predicted amino acid sequences of sMMO demonstrated that the sMMOs from these strains were closer to that from M. capsulatus Bath in the group X methanotrophs than to those from Methylosinus trichosporium OB3b and Methylocystis sp. strain M in the group 2 methanotrophs. Based on the sequence data of sMMO genes of the strains and other methanotrophs, the authors designed a new PCR primer to amplify sMMO gene fragments of all the known methanotrophs harboring the mmoX gene. The primer set was successfully used for detecting methanotrophs in the ground-water of trichloroethylene-contaminated sites during in situ-biostimulation treatments.

  13. [Effect of operational modes on community structure of type I methanotroph in the cover soil of municipal solid waste landfill].

    PubMed

    Yu, Ting; He, Pin-Jing; Lü, Fan; Shao, Li-Ming

    2008-10-01

    Type I methanotroph is crucial for methane oxidization and it responses fast to the changes in environment. In this study, 16S rDNA-based denaturing gradient gel electrophoresis (DGGE) gene fingerprint technology was applied to investigate the effect of operational modes, i. e. high-density polyethylene liner (HDPE) isolation or subsurface irrigation of landfill leachate and vegetation, on community structure and diversity of type I methanotroph in soils covering municipal solid waste landfill. 16S rDNA based phylogenetic analysis reveals type I methanotroph in all tested soils belongs to Methylobacter. According to Shannon-Wiener diversity index and principal component analysis, landfill leachate subsurface irrigation and vegetation have more impact on type I methanotroph community structure and diversity than HDPE liner isolation does, and they reduce type I methanotroph diversity. Leachate irrigation is supposed to inhibit the growth of Methylobacter population. Community structure of type I methanotroph in landfill cover soil isolated by HDPE, i.e. invaded by landfill gas, shifts during long-term gas interference. When cover age is 1.5 years old, Shannon-Wiener diversity index of type I methanotroph reaches its maximum.

  14. Draft Genome Sequence of the Methanotrophic Gammaproteobacterium Methyloglobulus morosus DSM 22980 Strain KoM1

    PubMed Central

    Poehlein, Anja; Deutzmann, Jörg S.; Daniel, Rolf

    2013-01-01

    Here, we report the draft genome sequence of the methanotrophic gammaproteobacterium Methyloglobulus morosus DSM 22980 strain KoM1, which is proposed to be the type species for the novel genus Methyloglobulus. The genome (4.143 Mb) consists of a single circular chromosome and harbors genes for 2-aminoethylphosphonate (ciliatine) biosynthesis. PMID:24356841

  15. [Depth Profiles of Methane Oxidation Kinetics and the Related Methanotrophic Community in a Simulated Landfill Cover].

    PubMed

    Xing, Zhi-lin; Zhao, Tian-tao; Gao, Yan-hui; He, Zhi; Yang, Xu; Peng, Xu-ya

    2015-11-01

    Simulated landfill cover with real time online monitoring system was developed using cover soils. Then the system started and the concentrations of bio-gas in various depths were continuously monitored, and it was found that the system ran continually and stably after 2-3 h when methane flux changed. After that, the relationship between regularity of methane oxidation and methane flux in landfill cover was analyzed. The results indicated that concentration of oxygen decreased with increasing methane flux when the depth was deeper than 20 cm, and no obvious correlation between oxygen concentration in landfill cover surface and methane flux, however, methane oxidation rate showed positive correlation with methane flux in various depths (range of R2 was 0.851-0.999). Kinetics of CH4 oxidation in landfill cover was fitted by CH4 -O2 dual-substrate model (range of R2 was 0.902-0.955), the half-saturation constant K(m) increasing with depth was 0.157-0.729 in dynamic condition. Finally, methanotrophs community structure in original cover soil sample and that in simulated landfill cover were investigated by high-throughout sequencing technology, and the statistics indicated that the abundance and species of methanotrophs in simulated landfill cover significantly increased compared with those in original cover soil sample, and type I methanotrophs including Methylobacter and Methylophilaceae and type II methanotrophs Methylocystis were dominant species.

  16. Methanotrophic production of copolymer, poly(hydroxybutyrate-co-hydroxyvalerate), with high hydroxyvalerate content

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Type II methanotrophic bacteria are a promising production platform for PHA biopolymers. These bacteria are known to produce pure poly-3-hydroxybutyrate homopolymer. We describe the production of a wide range of PHB-co-HV co-polymers by the co-feeding of methane and valerate. The ratio of HB to HV m...

  17. What Is Aerobic Dancing?

    MedlinePlus

    ... aerobics can reach up to six times the force of gravity, which is transmitted to each of the 26 bones in the foot. Because of the many side-to-side motions, shoes need an arch design that will compensate ...

  18. All Three Endogenous Quinone Species of Escherichia coli Are Involved in Controlling the Activity of the Aerobic/Anaerobic Response Regulator ArcA

    PubMed Central

    van Beilen, Johan W. A.; Hellingwerf, Klaas J.

    2016-01-01

    The enteron Escherichia coli is equipped with a branched electron transfer chain that mediates chemiosmotic electron transfer, that drives ATP synthesis. The components of this electron transfer chain couple the oxidation of available electron donors from cellular metabolism (e.g., NADH, succinate, lactate, formate, etc.) to the reduction of electron acceptors like oxygen, nitrate, fumarate, di-methyl-sulfoxide, etc. Three different quinones, i.e., ubiquinone, demethyl-menaquinone and menaquinone, couple the transfer of electrons between the dehydrogenases and reductases/oxidases that constitute this electron transfer chain, whereas, the two-component regulation system ArcB/A regulates gene expression, to allow the organism to adapt itself to the ambient conditions of available electron donors and acceptors. Here, we report that E. coli can grow and adjust well to transitions in the availability of oxygen, with any of the three quinones as its single quinone. In all three ‘single-quinone’ E. coli strains transitions in the activity of ArcB are observed, as evidenced by changes in the level of phosphorylation of the response regulator ArcA, upon depletion/readmission of oxygen. These results lead us to conclude that all quinol species of E. coli can reduce (i.e., activate) the sensor ArcB and all three quinones oxidize (i.e., de-activate) it. These results also confirm our earlier conclusion that demethyl-menaquinone can function in aerobic respiration. PMID:27656164

  19. Test Plan for Methanotrophic Bioreactor at Savannah River Site-TNX

    SciTech Connect

    Berry, C.J.

    1994-10-04

    The primary purpose of this project is to demonstrate the feasibility and practicality of operating a methanotrophic mobile trickle filter bioreactor (MMB) unit to effectively reduce or eliminate trichloroethylene (TCE) and associated hydrocarbons from contaminated groundwater. The two-column trickle filter system can process 1.67 gallons per minute (gpm) of contaminated groundwater. During this project, the pilot system will evaluate, optimize, and demonstrate methanotrophic treatment technology (MTT). The mobile system will receive a 1--4% methane to air mixture for stimulating the methanotrophic TCE degrading bacteria, thereby increasing the rates of degradation of these contaminants. This project will also evaluate the efficacy of different bacteria for degrading TCE for use in the system at the laboratory-scale sample groundwater monitoring wells at TNX and set up the system for continued operation. The trickle filter system may be used to inexpensively treat other small-scale organic waste streams at SRS after the initial start-up. The MTT was demonstrated as an effective and efficient method of degrading TCE in the laboratory and during a field-scale in situ demonstration for degrading TCE in a groundwater plume at SRS. The methanotrophic bacteria increase significantly in population numbers and in the production of methane monooxygenase (MMO), an extremely powerful oxidizer. MMO was demonstrated as effective in oxidizing TCE and other recalcitrant compounds in laboratory studies. In the presence of MMO, TCE is oxidized to TCE-epoxide, which breaks down spontaneously into simple, easily degraded, daughter compounds. The system will receive a 1--4% methane to air mixture, which will effectively grow and maintain the methanotrophic bacteria that will degrade TCE. This demonstration will have broad applications to bioremediating contaminated groundwater systems where in situ bioremediation is not practical.

  20. Bacterial community structure across environmental gradients in permafrost thaw ponds: methanotroph-rich ecosystems.

    PubMed

    Crevecoeur, Sophie; Vincent, Warwick F; Comte, Jérôme; Lovejoy, Connie

    2015-01-01

    Permafrost thawing leads to the formation of thermokarst ponds that potentially emit CO2 and CH4 to the atmosphere. In the Nunavik subarctic region (northern Québec, Canada), these numerous, shallow ponds become well-stratified during summer. This creates a physico-chemical gradient of temperature and oxygen, with an upper oxic layer and a bottom low oxygen or anoxic layer. Our objective was to determine the influence of stratification and related limnological and landscape properties on the community structure of potentially active bacteria in these waters. Samples for RNA analysis were taken from ponds in three contrasting valleys across a gradient of permafrost degradation. A total of 1296 operational taxonomic units were identified by high throughput amplicon sequencing, targeting bacterial 16S rRNA that was reverse transcribed to cDNA. β-proteobacteria were the dominant group in all ponds, with highest representation by the genera Variovorax and Polynucleobacter. Methanotrophs were also among the most abundant sequences at most sites. They accounted for up to 27% of the total sequences (median of 4.9% for all samples), indicating the importance of methane as a bacterial energy source in these waters. Both oxygenic (cyanobacteria) and anoxygenic (Chlorobi) phototrophs were also well-represented, the latter in the low oxygen bottom waters. Ordination analyses showed that the communities clustered according to valley and depth, with significant effects attributed to dissolved oxygen, pH, dissolved organic carbon, and total suspended solids. These results indicate that the bacterial assemblages of permafrost thaw ponds are filtered by environmental gradients, and are complex consortia of functionally diverse taxa that likely affect the composition as well as magnitude of greenhouse gas emissions from these abundant waters.

  1. Bacterial community structure across environmental gradients in permafrost thaw ponds: methanotroph-rich ecosystems

    PubMed Central

    Crevecoeur, Sophie; Vincent, Warwick F.; Comte, Jérôme; Lovejoy, Connie

    2015-01-01

    Permafrost thawing leads to the formation of thermokarst ponds that potentially emit CO2 and CH4 to the atmosphere. In the Nunavik subarctic region (northern Québec, Canada), these numerous, shallow ponds become well-stratified during summer. This creates a physico-chemical gradient of temperature and oxygen, with an upper oxic layer and a bottom low oxygen or anoxic layer. Our objective was to determine the influence of stratification and related limnological and landscape properties on the community structure of potentially active bacteria in these waters. Samples for RNA analysis were taken from ponds in three contrasting valleys across a gradient of permafrost degradation. A total of 1296 operational taxonomic units were identified by high throughput amplicon sequencing, targeting bacterial 16S rRNA that was reverse transcribed to cDNA. β-proteobacteria were the dominant group in all ponds, with highest representation by the genera Variovorax and Polynucleobacter. Methanotrophs were also among the most abundant sequences at most sites. They accounted for up to 27% of the total sequences (median of 4.9% for all samples), indicating the importance of methane as a bacterial energy source in these waters. Both oxygenic (cyanobacteria) and anoxygenic (Chlorobi) phototrophs were also well-represented, the latter in the low oxygen bottom waters. Ordination analyses showed that the communities clustered according to valley and depth, with significant effects attributed to dissolved oxygen, pH, dissolved organic carbon, and total suspended solids. These results indicate that the bacterial assemblages of permafrost thaw ponds are filtered by environmental gradients, and are complex consortia of functionally diverse taxa that likely affect the composition as well as magnitude of greenhouse gas emissions from these abundant waters. PMID:25926816

  2. Genome Sequence of the Arctic Methanotroph Methylobacter tundripaludum SV96

    SciTech Connect

    Svenning, Mette M; Hestnes, Anne Grethe; Wartiainen, Ingvild; Stein, Lisa Y.; Klotz, Martin G; Kalyuzhnaya, Marina G.; Spang, Anja; Bringel, Francoise O.; Vuilleumier, Stephane; Lajus, Aurelie; Cheng, Jan-Fang; Goodwin, Lynne A.; Ivanova, N; Han, James; Han, Cliff; Hauser, Loren John; Held, Brittany; Land, Miriam L; Lapidus, Alla L.; Lucas, Susan; Nolan, Matt; Pitluck, Sam; Woyke, Tanja

    2011-01-01

    Methylobacter tundripaludum SV96(T) (ATCC BAA-1195) is a psychrotolerant aerobic methane-oxidizing gammaproteobacterium (Methylococcales, Methylococcaceae) living in High Arctic wetland soil. The strain was isolated from soil harvested in July 1996 close to the settlement Ny-Alesund, Svalbard, Norway (78 degrees 56'N, 11 degrees 53'E), and described as a novel species in 2006. The genome includes pmo and pxm operons encoding copper membrane monooxygenases (Cu-MMOs), genes required for nitrogen fixation, and the nirS gene implicated in dissimilatory nitrite reduction to NO but no identifiable inventory for further processing of nitrogen oxides. These genome data provide the basis to investigate M. tundripaludum SV96, identified as a major player in the biogeochemistry of Arctic environments.

  3. ENZYME ACTIVITY PROBE AND GEOCHEMICAL ASSESSMENT FOR POTENTIAL AEROBIC COMETABOLISM OF TRICHLOROETHENE IN GROUNDWATER OF THE NORTHWEST PLUME, PADUCAH GASEOUS DIFFUSION PLANT, KENTUCKY

    SciTech Connect

    Looney, B; M. Hope Lee, M; S. K. Hampson, S

    2008-06-27

    The overarching objective of the Paducah Gaseous Diffusion Plant (PGDP) enzyme activity probe (EAP) effort is to determine if aerobic cometabolism is contributing to the attenuation of trichloroethene (TCE) and other chlorinated solvents in the contaminated groundwater beneath PGDP. The site-specific objective for the EAP assessment is to identify if key metabolic pathways are present and expressed in the microbial community--namely the pathways that are responsible for degradation of methane and aromatic (e.g. toluene, benzene, phenol) substrates. The enzymes produced to degrade methane and aromatic compounds also break down TCE through a process known as cometabolism. EAPs directly measure if methane and/or aromatic enzyme production pathways are operating and, for the aromatic pathways, provide an estimate of the number of active organisms in the sampled groundwater. This study in the groundwater plumes at PGDP is a major part of a larger scientific effort being conducted by Interstate Technology and Regulatory Council (ITRC), U.S. Department of Energy (DOE) Office of Environmental Management (EM), Savannah River National Laboratory (SRNL), and North Wind Inc. in which EAPs are being applied to contaminated groundwater from diverse hydrogeologic and plume settings throughout the U.S. to help standardize their application as well as their interpretation. While EAP data provide key information to support the site specific objective for PGDP, several additional lines of evidence are being evaluated to increase confidence in the determination of the occurrence of biodegradation and the rate and sustainability of aerobic cometabolism. These complementary efforts include: (1) Examination of plume flowpaths and comparison of TCE behavior to 'conservative' tracers in the plume (e.g., {sup 99}Tc); (2) Evaluation of geochemical conditions throughout the plume; and (3) Evaluation of stable isotopes in the contaminants and their daughter products throughout the plume. If

  4. Quantifying the Presence and Activity of Aerobic, Vinyl Chloride-Degrading Microorganisms in Dilute Groundwater Plumes by Using Real-Time PCR

    DTIC Science & Technology

    2013-07-01

    natural attenuation of VC and will thus support existing anaerobic bioremediation technologies that generate VC as a metabolic intermediate and...Defense (DoD). Anaerobic reductive dechlorination is a promising biotechnology for remediation of PCE- and TCE-contaminated groundwater, but the...water source zones. At some sites, VC will escape the anaerobic zone and enter aerobic groundwater, forming dilute plumes. Aerobic groundwater

  5. Low energy emulsion-based fermentation enabling accelerated methane mass transfer and growth of poly(3-hydroxybutyrate)-accumulating methanotrophs.

    PubMed

    Myung, Jaewook; Kim, Minkyu; Pan, Ming; Criddle, Craig S; Tang, Sindy K Y

    2016-05-01

    Methane is a low-cost feedstock for the production of polyhydroxyalkanoate biopolymers, but methanotroph fermentations are limited by the low solubility of methane in water. To enhance mass transfer of methane to water, vigorous mixing or agitation is typically used, which inevitably increases power demand and operational costs. This work presents a method for accelerating methane mass transfer without agitation by growing methanotrophs in water-in-oil emulsions, where the oil has a higher solubility for methane than water does. In systems without agitation, the growth rate of methanotrophs in emulsions is five to six times that of methanotrophs in the medium-alone incubations. Within seven days, cells within the emulsions accumulate up to 67 times more P3HB than cells in the medium-alone incubations. This is achieved due to the increased interfacial area of the aqueous phase, and accelerated methane diffusion through the oil phase.

  6. Cardiometabolic Biomarkers in Young Black Girls: Relations to Body Fatness and Aerobic Fitness, and Effects of a Randomized Physical Activity Trial

    PubMed Central

    Gutin, Bernard; Harris, Ryan A.; Howe, Cheryl A.; Johnson, Maribeth H.; Zhu, Haidong; Dong, Yanbin

    2011-01-01

    There is little evidence from randomized trials showing that physical activity alone influences biomarker profiles in youths. This study tested two hypotheses: (i) that elevated body fatness and poor fitness would be associated with unfavorable levels of cardiometabolic biomarkers in 8–12-y-old black girls (n = 242) and (ii) that a 10-mo PA intervention would have favorable effects on the fatness-related cardiometabolic biomarkers. At baseline, all fatness indices (i.e., percent body fat, visceral adipose tissue, BMI, and waist circumference) were significantly (P < 0.05) associated with unfavorable levels of insulin, glucose, systolic BP, diastolic BP, triglycerides, C-reactive protein (CRP), and fibrinogen. Aerobic fitness was significantly (P < 0.05) associated with favorable levels of insulin, CRP, fibrinogen, and HDL2. The PA intervention had significant and favorable effects on fitness, fatness, and two biomarkers—resting heart rate and LDL cholesterol. More research is needed to clarify what types of interventions can enhance the cardiometabolic health of youths. PMID:22007244

  7. Voltammetric characterization of the aerobic energy-dissipating nitrate reductase of Paracoccus pantotrophus: exploring the activity of a redox-balancing enzyme as a function of electrochemical potential.

    PubMed

    Gates, Andrew J; Richardson, David J; Butt, Julea N

    2008-01-01

    Paracoccus pantotrophus expresses two nitrate reductases associated with respiratory electron transport, termed NapABC and NarGHI. Both enzymes derive electrons from ubiquinol to reduce nitrate to nitrite. However, while NarGHI harnesses the energy of the quinol/nitrate couple to generate a transmembrane proton gradient, NapABC dissipates the energy associated with these reducing equivalents. In the present paper we explore the nitrate reductase activity of purified NapAB as a function of electrochemical potential, substrate concentration and pH using protein film voltammetry. Nitrate reduction by NapAB is shown to occur at potentials below approx. 0.1 V at pH 7. These are lower potentials than required for NarGH nitrate reduction. The potentials required for Nap nitrate reduction are also likely to require ubiquinol/ubiquinone ratios higher than are needed to activate the H(+)-pumping oxidases expressed during aerobic growth where Nap levels are maximal. Thus the operational potentials of P. pantotrophus NapAB are consistent with a productive role in redox balancing. A Michaelis constant (K(M)) of approx. 45 muM was determined for NapAB nitrate reduction at pH 7. This is in line with studies on intact cells where nitrate reduction by Nap was described by a Monod constant (K(S)) of less than 15 muM. The voltammetric studies also disclosed maximal NapAB activity in a narrow window of potential. This behaviour is resistant to change of pH, nitrate concentration and inhibitor concentration and its possible mechanistic origins are discussed.

  8. Relations of sex, age, perceived fitness, and aerobic activity with social physique anxiety in adults sixty years and older.

    PubMed

    Lanning, Beth A; Bowden, Rodney G; Owens, Robin; Massey-Stokes, Marilyn

    2004-12-01

    Self-reported physical activity, and perceived fitness were examined to assess their effects on social physique anxiety in a sample of older individuals (N= 249; M age=70.4 yr., SD=8.2). Participants reported their fitness as "average" to "above average." There were no significant effects of perceived fitness or age on social physique anxiety scores. The women had significantly higher social physique anxiety scores than the men.

  9. A methanotroph-based biorefinery: Potential scenarios for generating multiple products from a single fermentation.

    PubMed

    Strong, P J; Kalyuzhnaya, M; Silverman, J; Clarke, W P

    2016-09-01

    Methane, a carbon source for methanotrophic bacteria, is the principal component of natural gas and is produced during anaerobic digestion of organic matter (biogas). Methanotrophs are a viable source of single cell protein (feed supplement) and can produce various products, since they accumulate osmolytes (e.g. ectoine, sucrose), phospholipids (potential biofuels) and biopolymers (polyhydroxybutyrate, glycogen), among others. Other cell components, such as surface layers, metal chelating proteins (methanobactin), enzymes (methane monooxygenase) or heterologous proteins hold promise as future products. Here, scenarios are presented where ectoine, polyhydroxybutyrate or protein G are synthesised as the primary product, in conjunction with a variety of ancillary products that could enhance process viability. Single or dual-stage processes and volumetric requirements for bioreactors are discussed, in terms of an annual biomass output of 1000 tonnesyear(-1). Product yields are discussed in relation to methane and oxygen consumption and organic waste generation.

  10. Cyclic, alternating methane and nitrogen limitation increases PHB production in a methanotrophic community.

    PubMed

    Pieja, Allison J; Sundstrom, Eric R; Criddle, Craig S

    2012-03-01

    To identify feast-famine strategies that favor PHB accumulation in Type II methanotrophic proteobacteria, three sequencing batch reactors seeded with a defined inoculum of Type II methanotrophs were subjected to 24-h cycles consisting of (1) repeated nitrogen limitation, (2) repeated nitrogen and oxygen limitation, and (3) repeated nitrogen and methane limitation. PHB levels within each reactor and capacity to produce PHB in offline batch incubations were monitored over 11 cycles. PHB content increased only in the reactor limited by both nitrogen and methane. This reactor became dominated by Methylocystis parvus OBBP with no detectable minority populations. It was concluded that repeated nitrogen and methane limitations favored PHB accumulation in strain OBBP and provided it with a competitive advantage under the conditions imposed.

  11. Comparative effects of three 48-week community-based physical activity and exercise interventions on aerobic capacity, total cholesterol and mean arterial blood pressure

    PubMed Central

    Mann, Steven; Jimenez, Alfonso; Domone, Sarah; Beedie, Chris

    2016-01-01

    Aim Insufficient research examines the treatment effectiveness of real-world physical activity (PA) interventions. Purpose We investigated the effects of 3 interventions on directly measured cardiovascular variables. All treatments and measures were administered in community settings by fitness centre staff. Methods Participants were sedentary individuals receiving no medication to reduce cardiovascular disease (CVD) risk (n=369, age 43 ±5 years). In a semirandomised design, participants were allocated to a structured gym exercise programme (STRUC), unstructured gym exercise (FREE), physical activity counselling (PAC) or a measurement-only control condition (CONT). Measures were: predicted aerobic capacity (VO2: mL kg min), mean arterial blood pressure (MAP: mm Hg) and total cholesterol (TC: mmol/L), and were taken at baseline and 48 weeks. Results Data analysis indicated a statistically significant deterioration in TC in CONT (0.8%, SD=0.5, p=0.005), and a statistically significant improvement in MAP in STRUC (2.5%, SD=8.3, p=0.004). Following a median split by baseline VO2, paired-sample t tests indicated significant improvements in VO2 among low-fit participants in STRUC (3.5%, SD=4.8, p=0.003), PAC (3.3%, SD=7.7, p=0.050) and FREE (2.6%, SD=4.8, p=0.006), and significant deterioration of VO2 among high-fit participants in FREE (−2.0%, SD=5.6, p=0.037), and PAC (−3.2%, SD=6.4, p=0.031). Conclusions Several forms of PA may offset increased cholesterol resulting from inactivity. Structured PA (exercise) might be more effective than either unstructured PA or counselling in improving blood pressure, and community-based PA interventions might be more effective in improving VO2 among low-fit than among high-fit participants. PMID:27900172

  12. Physical Activity Differentially Affects the Cecal Microbiota of Ovariectomized Female Rats Selectively Bred for High and Low Aerobic Capacity.

    PubMed

    Liu, Tzu-Wen; Park, Young-Min; Holscher, Hannah D; Padilla, Jaume; Scroggins, Rebecca J; Welly, Rebecca; Britton, Steven L; Koch, Lauren G; Vieira-Potter, Victoria J; Swanson, Kelly S

    2015-01-01

    The gut microbiota is considered a relevant factor in obesity and associated metabolic diseases, for which postmenopausal women are particularly at risk. Increasing physical activity has been recognized as an efficacious approach to prevent or treat obesity, yet the impact of physical activity on the microbiota remains under-investigated. We examined the impacts of voluntary exercise on host metabolism and gut microbiota in ovariectomized (OVX) high capacity (HCR) and low capacity running (LCR) rats. HCR and LCR rats (age = 27 wk) were OVX and fed a high-fat diet (45% kcal fat) ad libitum and housed in cages equipped with (exercise, EX) or without (sedentary, SED) running wheels for 11 wk (n = 7-8/group). We hypothesized that increased physical activity would hinder weight gain, increase metabolic health and shift the microbiota of LCR rats, resulting in populations more similar to that of HCR rats. Animals were compared for characteristic metabolic parameters including body composition, lipid profile and energy expenditure; whereas cecal digesta were collected for DNA extraction. 16S rRNA gene-based amplicon Illumina MiSeq sequencing was performed, followed by analysis using QIIME 1.8.0 to assess cecal microbiota. Voluntary exercise decreased body and fat mass, and normalized fasting NEFA concentrations of LCR rats, despite only running one-third the distance of HCR rats. Exercise, however, increased food intake, weight gain and fat mass of HCR rats. Exercise clustered the gut microbial community of LCR rats, which separated them from the other groups. Assessments of specific taxa revealed significant (p<0.05) line by exercise interactions including shifts in the abundances of Firmicutes, Proteobacteria, and Cyanobacteria. Relative abundance of Christensenellaceae family was higher (p = 0.026) in HCR than LCR rats, and positively correlated (p<0.05) with food intake, body weight and running distance. These findings demonstrate that exercise differentially impacts

  13. Potential of pmoA amplicon pyrosequencing for methanotroph diversity studies.

    PubMed

    Lüke, Claudia; Frenzel, Peter

    2011-09-01

    We analyzed the potential of pmoA amplicon pyrosequencing compared to that of Sanger sequencing with paddy soils as a model environment. We defined operational taxonomic unit (OTU) cutoff values of 7% and 18%, reflecting methanotrophic species and major phylogenetic pmoA lineages, respectively. Major lineages were already well covered by clone libraries; nevertheless, pyrosequencing provided a higher level of diversity at the species level.

  14. High-affinity methane oxidation by a soil enrichment culture containing a type II methanotroph

    SciTech Connect

    Dunfield, P.F. |; Liesack, W.; Henckel, T.; Conrad, R.; Knowles, R.

    1999-03-01

    Methanotrophic bacteria in an organic soil were enriched on gaseous mixing ratios of <275 parts per million of volume (ppmv) of methane (CH{sub 4}). After 4 years of growth and periodic dilution, a mixed culture was obtained which displayed an apparent half-saturation constant [K{sub m(app)}] for CH{sub 4} of 56 to 186 nM (40 to 132 ppmv). This value was the same as that measured in the soil itself and about 1 order of magnitude lower than reported values for pure cultures of methane oxidizers. However, the K{sub m(app)} increased when the culture was transferred to higher mixing ratios of CH{sub 4}. Denaturing gradient gel electrophoresis of the enrichment grown on <275 ppmv of CH{sub 4} revealed a single gene product of pmoA, which codes for a subunit of particulate methane monooxygenase. This suggested that only one methanotroph species was present. This organism was isolated from a sample of the enrichment culture grown on 1% CH{sub 4} and phylogenetically positioned based on its 16S rRNA, pmoA, and mxaF gene sequences as a type II strain of the Methlocystis/Methylosinus group. A coculture of this strain with a Variovorax sp., when grown on <275 ppmv of CH{sub 4}, had a K{sub m(app)} similar to that of the initial enrichment culture. The data suggest that the affinity of methanotrophic bacteria for CH{sub 4} varies with growth conditions and that the oxidation of atmospheric CH{sub 4} observed in this soil is carried out by type II methanotrophic bacteria which are similar to characterized species.

  15. Electrolytic methanogenic-methanotrophic coupling for tetrachloroethylene bioremediation: proof of concept.

    PubMed

    Guiot, Serge R; Cimpoia, Ruxandra; Kuhn, Ramona; Alaplantive, Aude

    2008-04-15

    Coupling of methanogenic and methanotrophic catabolisms was performed in a single-stage technology equipped with a water electrolysis cell placed in the effluent recirculation loop. The electrolysis-generated hydrogen served as an electron donor for both bicarbonate reduction into CH4 and reductive dechlorination, while the O2 and CH4, supported the cometabolic oxidation of chlorinated intermediates left over by the tetrachloroethylene (PCE) transformation. The electrolytical methanogenic/methanotrophic coupled (eMaMoC) process was tested in a laboratory-scale setup at PCE loads ranging from 5 to 50 micromol/L(rx) x d (inlet concentrations from 4 to 11 mg/L), and at various hydraulic residence times (HRT). Degradation followed essentially a reductive dechlorination pathway from PCE to cis-1,2-dichloroethene (DCE), and an oxidative pathway from DCE to CO2. PCE reductive dechlorination to DCE was consistently over 98% while a maximum oxidative DCE mineralization of 89% was obtained at a load of 4.3 micromol PCE/ L(rx) x d and an HRT of 6 days. Controlling dissolved oxygen concentrations within a relatively low range (2-3 mg/L) seemed instrumental to sustain the overall degradation capacity. Degradation kinetics were further evaluated: the apparent half-saturation constant (K(s)) had to be set relatively high (29 microM) for the simulated data to best fit the experimental ones. In spite of such kinetic limitations, the eMaMoC system, while fueled by water electrolysis, was effective in building and sustaining a functional methanogenic/methanotrophic consortium capable of significant PCE mineralization in a single-stage process. Hence, degradation standards are within reach so long as the methanotrophic DCE-oxidizing potential, including substrate affinity, are optimized and HRT accordingly adjusted.

  16. Clay enhancement of methane, low molecular weight hydrocarbon and halocarbon conversion by methanotrophic bacteria

    SciTech Connect

    Apel, W.A.; Dugan, P.R.

    1991-12-31

    The invention described in this report relates to a combined system of an apparatus and a method of increasing the rates of oxidation of gases and hazardous vapors by methanotrophic and other bacteria. The gases of interest are methane and trichlorethylene and other hazardous vapors. In a preferred embodiment, the oxidation rate of methane is improved by the addition of clays, e.g., kaolin, sometimes called ``China clay.``

  17. Expanding the verrucomicrobial methanotrophic world: description of three novel species of Methylacidimicrobium gen. nov.

    PubMed

    van Teeseling, Muriel C F; Pol, Arjan; Harhangi, Harry R; van der Zwart, Sietse; Jetten, Mike S M; Op den Camp, Huub J M; van Niftrik, Laura

    2014-11-01

    Methanotrophic Verrucomicrobia have been found in geothermal environments characterized by high temperatures and low pH values. However, it has recently been hypothesized that methanotrophic Verrucomicrobia could be present under a broader range of environmental conditions. Here we describe the isolation and characterization of three new species of mesophilic acidophilic verrucomicrobial methanotrophs from a volcanic soil in Italy. The three new species showed 97% to 98% 16S rRNA gene identity to each other but were related only distantly (89% to 90% on the 16S rRNA level) to the thermophilic genus Methylacidiphilum. We propose the new genus Methylacidimicrobium, including the novel species Methylacidimicrobium fagopyrum, Methylacidimicrobium tartarophylax, and Methylacidimicrobium cyclopophantes. These mesophilic Methylacidimicrobium spp. were more acid tolerant than their thermophilic relatives; the most tolerant species, M. tartarophylax, still grew at pH 0.5. The variation in growth temperature optima (35 to 44°C) and maximum growth rates (µmax; 0.013 to 0.040 h(-1)) suggested that all species were adapted to a specific niche within the geothermal environment. All three species grew autotrophically using the Calvin cycle. The cells of all species contained glycogen particles and electron-dense particles in their cytoplasm as visualized by electron microscopy. In addition, the cells of one of the species (M. fagopyrum) contained intracytoplasmic membrane stacks. The discovery of these three new species and their growth characteristics expands the known diversity of verrucomicrobial methanotrophs and shows that they are present in many more ecosystems than previously assumed.

  18. The Acute Effect of Aerobic Exercise on Measures of Stress.

    ERIC Educational Resources Information Center

    Fort, Inza L.; And Others

    The immediate response of stress to aerobic exercise was measured by utilizing the Palmar Sweat Index (PSI) and the State-Trait Anxiety Inventory (STAI). Forty subjects (20 male and 20 female) from the ages of 18-30 sustained a single bout of aerobic activity for 30 minutes at 60 percent of their maximum heart rate. Pre-treatment procedures…

  19. Aerobic Fitness Thresholds Associated with Fifth Grade Academic Achievement

    ERIC Educational Resources Information Center

    Wittberg, Richard; Cottrell, Lesley A.; Davis, Catherine L.; Northrup, Karen L.

    2010-01-01

    Background: Whereas effects of physical fitness and physical activity on cognitive function have been documented, little is known about how they are related. Purpose: This study assessed student aerobic fitness measured by FITNESSGRAM Mile times and/or Pacer circuits and whether the nature of the association between aerobic fitness and…

  20. Implementation of Aerobic Programs.

    ERIC Educational Resources Information Center

    American Alliance for Health, Physical Education, Recreation and Dance (AAHPERD).

    This information is intended for health professionals interested in implementing aerobic exercise programs in public schools, institutions of higher learning, and business and industry workplaces. The papers are divided into three general sections. The introductory section presents a basis for adhering to a health fitness lifestyle, using…

  1. Aerobic Anoxygenic Phototrophic Bacteria

    PubMed Central

    Yurkov, Vladimir V.; Beatty, J. Thomas

    1998-01-01

    The aerobic anoxygenic phototrophic bacteria are a relatively recently discovered bacterial group. Although taxonomically and phylogenetically heterogeneous, these bacteria share the following distinguishing features: the presence of bacteriochlorophyll a incorporated into reaction center and light-harvesting complexes, low levels of the photosynthetic unit in cells, an abundance of carotenoids, a strong inhibition by light of bacteriochlorophyll synthesis, and the inability to grow photosynthetically under anaerobic conditions. Aerobic anoxygenic phototrophic bacteria are classified in two marine (Erythrobacter and Roseobacter) and six freshwater (Acidiphilium, Erythromicrobium, Erythromonas, Porphyrobacter, Roseococcus, and Sandaracinobacter) genera, which phylogenetically belong to the α-1, α-3, and α-4 subclasses of the class Proteobacteria. Despite this phylogenetic information, the evolution and ancestry of their photosynthetic properties are unclear. We discuss several current proposals for the evolutionary origin of aerobic phototrophic bacteria. The closest phylogenetic relatives of aerobic phototrophic bacteria include facultatively anaerobic purple nonsulfur phototrophic bacteria. Since these two bacterial groups share many properties, yet have significant differences, we compare and contrast their physiology, with an emphasis on morphology and photosynthetic and other metabolic processes. PMID:9729607

  2. Aerobic Dance in Public Schools.

    ERIC Educational Resources Information Center

    Chiles, Barbara Ann; Moore, Suzanne

    1981-01-01

    Aerobic dance offers a challenging workout in a social atmosphere. Though some physical education instructors tend to exclude dance units from the curriculum, most could teach aerobic dance if they had a basic knowledge of aerobic routines. The outline for a unit to be used in the class is presented. (JN)

  3. Analyses of Methanobactin, a Novel Copper-Binding Compound, or Chalkophore, from Methanotrophs

    NASA Astrophysics Data System (ADS)

    Semrau, J. D.; Yoon, S.; Dispirito, A.; Kraemer, S.

    2009-12-01

    Methanotrophs, cells that utilize methane as their sole carbon and energy source are known to have high requirements for copper. Many of these cells are known to synthesize a copper-chelating agent, or chalkophore, termed methanobactin that appears integral to copper uptake. Structural analyses indicate that methanobactin is a small chromopeptide that binds copper utilizing two alkylidene oxazolone rings. Using a suite of spectrophotemetric and calorimetry analyses, it was discovered that methanobactin preferentially binds copper, but also binds other metals, including gold, forming gold nanoparticles. To screen methanobactin production by methanotrophs, as well as to determine if other cells make chalkophores, a plate assay developed from the Chromo Azurol S (CAS) assay for siderophore production, was modified. In the standard CAS assay, a color change in CAS plate is observed as iron (III) ion weakly bound to CAS is taken up by siderophores. In our modified assay, iron (III) chloride of the initial CAS solution was substituted with copper(II) chloride. Assay results indicated that of the four tested methanotrophs (Methylomicrobium album BG8, Methylosinus trichosporium OB3b, Methylococcus capsulatus Bath, and Methylocystis parvus OBBP), only M. album BG8, M. trichosporium OB3b, and M. capsulatus produced methanobactin, while M. parvus OBBP did not. The assay can be easily adopted for detection of chalkophores in other microorganisms and detection as well as for screening of putative mutants of chalkophore synthesis.

  4. Are Symbiotic Methanotrophs Key Microbes for N Acquisition in Paddy Rice Root?

    PubMed Central

    Minamisawa, Kiwamu; Imaizumi-Anraku, Haruko; Bao, Zhihua; Shinoda, Ryo; Okubo, Takashi; Ikeda, Seishi

    2016-01-01

    The relationships between biogeochemical processes and microbial functions in rice (Oryza sativa) paddies have been the focus of a large number of studies. A mechanistic understanding of methane–nitrogen (CH4–N) cycle interactions is a key unresolved issue in research on rice paddies. This minireview is an opinion paper for highlighting the mechanisms underlying the interactions between biogeochemical processes and plant-associated microbes based on recent metagenomic, metaproteomic, and isotope analyses. A rice symbiotic gene, relevant to rhizobial nodulation and mycorrhization in plants, likely accommodates diazotrophic methanotrophs or the associated bacterial community in root tissues under low-N fertilizer management, which may permit rice plants to acquire N via N2 fixation. The amount of N fixed in rice roots was previously estimated to be approximately 12% of plant N based on measurements of 15N natural abundance in a paddy field experiment. Community analyses also indicate that methanotroph populations in rice roots are susceptible to environmental conditions such as the microclimate of rice paddies. Therefore, CH4 oxidation by methanotrophs is a driving force in shaping bacterial communities in rice roots grown in CH4-rich environments. Based on these findings, we propose a hypothesis with unanswered questions to describe the interplay between rice plants, root microbiomes, and their biogeochemical functions (CH4 oxidation and N2 fixation). PMID:26960961

  5. Improving the performance of an aerobic membrane bioreactor (MBR) treating pharmaceutical wastewater with powdered activated carbon (PAC) addition.

    PubMed

    Kaya, Yasemin; Bacaksiz, A Murat; Golebatmaz, Ugur; Vergili, Ilda; Gönder, Z Beril; Yilmaz, Gulsum

    2016-04-01

    In this study, the effects of organic loading rate (OLR) and the addition of powdered activated carbon (PAC) on the performance and membrane fouling of MBR were conducted to treat real pharmaceutical process wastewater. Over 145 days of operation, the MBR system was operated at OLRs ranging from 1 to 2 kg COD m(-3) day(-1) without sludge wasting. The addition of PAC provided an improvement in the flux, despite an increase in the OLR:PAC ratio. The results demonstrated that the hybrid PAC-MBR system maintained a reduced amount of membrane fouling and steadily increased the removal performance of etodolac. PAC addition reduced the deposition of extracellular polymeric substance and organic matter on the membrane surface and resulted an increase in COD removal even at higher OLRs with low PAC addition. Membrane fouling mechanisms were investigated using combined adsorption fouling models. Modified fouling index values and normalized mass transfer coefficient values indicated that predominant fouling mechanism was cake adsorption.

  6. Deciphering Community Structure of Methanotrophs Dwelling in Rice Rhizospheres of an Indian Rice Field Using Cultivation and Cultivation-Independent Approaches.

    PubMed

    Pandit, Pranitha S; Rahalkar, Monali C; Dhakephalkar, Prashant K; Ranade, Dilip R; Pore, Soham; Arora, Preeti; Kapse, Neelam

    2016-04-01

    Methanotrophs play a crucial role in filtering out methane from habitats, such as flooded rice fields. India has the largest area under rice cultivation in the world; however, to the best of our knowledge, methanotrophs have not been isolated and characterized from Indian rice fields. A cultivation strategy composing of a modified medium, longer incubation time, and serial dilutions in microtiter plates was used to cultivate methanotrophs from a rice rhizosphere sample from a flooded rice field in Western India. We compared the cultured members with the uncultured community as revealed by three culture-independent methods. A novel type Ia methanotroph (Sn10-6), at the rank of a genus, and a putative novel species of a type II methanotroph (Sn-Cys) were cultivated from the terminal positive dilution (10(-6)). From lower dilution (10(-4)), a strain of Methylomonas spp. was cultivated. All the three culture-independent analyses, i.e., pmoA clone library, terminal restriction fragment length polymorphism (T-RFLP), and metagenomics approach, revealed the dominance of type I methanotrophs. Only metagenomic analysis showed significant presence of type II methanotrophs, albeit in lower proportion (37 %). All the three isolates showed relevance to the methanotrophic community as depicted by uncultured methods; however, the cultivated members might not be the most dominant ones. In conclusion, a combined cultivation and cultivation-independent strategy yielded us a broader picture of the methanotrophic community from rice rhizospheres of a flooded rice field in India.

  7. Exposure to high glutamate concentration activates aerobic glycolysis but inhibits ATP-linked respiration in cultured cortical astrocytes.

    PubMed

    Shen, Yao; Tian, Yueyang; Shi, Xiaojie; Yang, Jianbo; Ouyang, Li; Gao, Jieqiong; Lu, Jianxin

    2014-08-01

    Astrocytes play a key role in removing the synaptically released glutamate from the extracellular space and maintaining the glutamate below neurotoxic level in the brain. However, high concentration of glutamate leads to toxicity in astrocytes, and the underlying mechanisms are unclear. The purpose of this study was to investigate whether energy metabolism disorder, especially impairment of mitochondrial respiration, is involved in the glutamate-induced gliotoxicity. Exposure to 10-mM glutamate for 48 h stimulated glycolysis and respiration in astrocytes. However, the increased oxygen consumption was used for proton leak and non-mitochondrial respiration, but not for oxidative phosphorylation and ATP generation. When the exposure time extended to 72 h, glycolysis was still activated for ATP generation, but the mitochondrial ATP-linked respiration of astrocytes was reduced. The glutamate-induced astrocyte damage can be mimicked by the non-metabolized substrate d-aspartate but reversed by the non-selective glutamate transporter inhibitor TBOA. In addition, the glutamate toxicity can be partially reversed by vitamin E. These findings demonstrate that changes of bioenergetic profile occur in cultured cortical astrocytes exposed to high concentration of glutamate and highlight the role of mitochondria respiration in glutamate-induced gliotoxicity in cortical astrocytes.

  8. A Randomized Trial Examining the Effects of Aerobic Physical Activity on Attention-Deficit/Hyperactivity Disorder Symptoms in Young Children

    PubMed Central

    Hoza, Betsy; Smith, Alan L.; Shoulberg, Erin K.; Linnea, Kate S.; Dorsch, Travis E.; Blazo, Jordan A.; Alerding, Caitlin M.; McCabe, George P.

    2014-01-01

    The goal of this study was to compare the effects of before school physical activity (PA) and sedentary classroom-based (SC) interventions on the symptoms, behavior, moodiness and peer functioning of young children (Mage = 6.83) at risk for attention-deficit/hyperactivity disorder (ADHD-risk; n = 94) and typically developing children (TD; n = 108). Children were randomly assigned to either PA or SC and participated in the assigned intervention 31 minutes per day, each school day, over the course of 12 weeks. Parent and teacher ratings of ADHD symptoms (inattention, hyperactivity/impulsivity), oppositional behavior, moodiness, behavior toward peers, and reputation with peers, were used as dependent variables. Primary analyses indicate that the PA intervention was more effective than the SC intervention at reducing inattention and moodiness in the home context. Less conservative follow-up analyses within ADHD status and intervention groups suggest that a PA intervention may reduce impairment associated with ADHD-risk in both home and school domains; interpretive caution is warranted, however, given the liberal approach to these analyses. Unexpectedly, these findings also indicate the potential utility of a before school SC intervention as a tool for managing ADHD symptoms. Inclusion of a no treatment control group in future studies will enable further understanding of PA as an alternative management strategy for ADHD symptoms. PMID:25201345

  9. Partial oxidative conversion of methane to methanol through selective inhibition of methanol dehydrogenase in methanotrophic consortium from landfill cover soil.

    PubMed

    Han, Ji-Sun; Ahn, Chang-Min; Mahanty, Biswanath; Kim, Chang-Gyun

    2013-11-01

    Using a methanotrophic consortium (that includes Methylosinus sporium NCIMB 11126, Methylosinus trichosporium OB3b, and Methylococcus capsulatus Bath) isolated from a landfill site, the potential for partial oxidation of methane into methanol through selective inhibition of methanol dehydrogenase (MDH) over soluble methane monooxygenase (sMMO) with some selected MDH inhibitors at varied concentration range, was evaluated in batch serum bottle and bioreactor experiments. Our result suggests that MDH activity could effectively be inhibited either at 40 mM of phosphate, 100 mM of NaCl, 40 mM of NH4Cl or 50 μM of EDTA with conversion ratios (moles of CH3OH produced per mole CH4 consumed) of 58, 80, 80, and 43 %, respectively. The difference between extent of inhibition in MDH activity and sMMO activity was significantly correlated (n = 6, p < 0.05) with resultant methane to methanol conversion ratio. In bioreactor study with 100 mM of NaCl, a maximum specific methanol production rate of 9 μmol/mg h was detected. A further insight with qPCR analysis of MDH and sMMO coding genes revealed that the gene copy number continued to increase along with biomass during reactor operation irrespective of presence or absence of inhibitor, and differential inhibition among two enzymes was rather the key for methanol production.

  10. Effects of ingesting JavaFit Energy Extreme functional coffee on aerobic and anaerobic fitness markers in recreationally-active coffee consumers.

    PubMed

    Roberts, Michael D; Taylor, Lemuel W; Wismann, Jennifer A; Wilborn, Colin D; Kreider, Richard B; Willoughby, Darryn S

    2007-12-08

    The purpose of this study was to examine the effects of ingesting JavaFittrade mark Energy Extreme (JEE) on aerobic and anaerobic performance measures in recreationally-active male and female coffee drinkers. Five male (27.6 +/- 4.2 yrs, 93.2 +/- 11.7 kg, 181.6 +/- 6.9 cm) and five female (29 +/- 4.6 yrs, 61.5 +/- 9.2 kg, 167.6 +/- 6.9 cm) regular coffee drinkers (i.e., 223.9 +/- 62.7 mg.d-1 of caffeine) participated in this study. In a cross-over, randomized design, participants performed a baseline (BASELINE) graded treadmill test (GXT) for peak VO2 assessment and a Wingate test for peak power. Approximately 3-4 d following BASELINE testing, participants returned to the lab for the first trial and ingested 354 ml of either JEE or decaffeinated coffee (DECAF), after which they performed a GXT and Wingate test. Criterion measures during the GXT included an assessment of peakVO2 at maximal exercise, as well as VO2 at 3 minutes and 10 minutes post-exercise. Additionally, time-to-exhaustion (TTE), maximal RPE, mean heart rate (HR), mean systolic pressure (SBP), and mean diastolic blood pressure (DBP) were measured during each condition. Criterion measures for the Wingate included mean HR, SBP, DBP, peak power, and time to peak power (TTP). Participants then returned to the lab approximately one week later to perform the second trial under the same conditions as the first, except consuming the remaining coffee. Data were analyzed using a one way ANOVA (p < 0.05). Our results indicate that JEE significantly increased VO2 at 3 minutes post-exercise when compared to BASELINE (p = 0.04) and DECAF (p = 0.02) values, which may be beneficial in enhancing post-exercise fat metabolism.

  11. Effects of ingesting JavaFit Energy Extreme functional coffee on aerobic and anaerobic fitness markers in recreationally-active coffee consumers

    PubMed Central

    Roberts, Michael D; Taylor, Lemuel W; Wismann, Jennifer A; Wilborn, Colin D; Kreider, Richard B; Willoughby, Darryn S

    2007-01-01

    The purpose of this study was to examine the effects of ingesting JavaFit™ Energy Extreme (JEE) on aerobic and anaerobic performance measures in recreationally-active male and female coffee drinkers. Five male (27.6 ± 4.2 yrs, 93.2 ± 11.7 kg, 181.6 ± 6.9 cm) and five female (29 ± 4.6 yrs, 61.5 ± 9.2 kg, 167.6 ± 6.9 cm) regular coffee drinkers (i.e., 223.9 ± 62.7 mg·d-1 of caffeine) participated in this study. In a cross-over, randomized design, participants performed a baseline (BASELINE) graded treadmill test (GXT) for peak VO2 assessment and a Wingate test for peak power. Approximately 3–4 d following BASELINE testing, participants returned to the lab for the first trial and ingested 354 ml of either JEE or decaffeinated coffee (DECAF), after which they performed a GXT and Wingate test. Criterion measures during the GXT included an assessment of peakVO2 at maximal exercise, as well as VO2 at 3 minutes and 10 minutes post-exercise. Additionally, time-to-exhaustion (TTE), maximal RPE, mean heart rate (HR), mean systolic pressure (SBP), and mean diastolic blood pressure (DBP) were measured during each condition. Criterion measures for the Wingate included mean HR, SBP, DBP, peak power, and time to peak power (TTP). Participants then returned to the lab approximately one week later to perform the second trial under the same conditions as the first, except consuming the remaining coffee. Data were analyzed using a one way ANOVA (p < 0.05). Our results indicate that JEE significantly increased VO2 at 3 minutes post-exercise when compared to BASELINE (p = 0.04) and DECAF (p = 0.02) values, which may be beneficial in enhancing post-exercise fat metabolism. PMID:18067677

  12. Novel [NiFe]- and [FeFe]-hydrogenase gene transcripts indicative of active facultative aerobes and obligate anaerobes in earthworm gut contents.

    PubMed

    Schmidt, Oliver; Wüst, Pia K; Hellmuth, Susanne; Borst, Katharina; Horn, Marcus A; Drake, Harold L

    2011-09-01

    The concomitant occurrence of molecular hydrogen (H(2)) and organic acids along the alimentary canal of the earthworm is indicative of ongoing fermentation during gut passage. Fermentative H(2) production is catalyzed by [FeFe]-hydrogenases and group 4 [NiFe]-hydrogenases in obligate anaerobes (e.g., Clostridiales) and facultative aerobes (e.g., Enterobacteriaceae), respectively, functional groups that might respond differently to contrasting redox conditions. Thus, the objectives of this study were to assess the redox potentials of the alimentary canal of Lumbricus terrestris and analyze the hydrogenase transcript diversities of H(2) producers in glucose-supplemented gut content microcosms. Although redox potentials in the core of the alimentary canal were variable on an individual worm basis, average redox potentials were similar. The lowest redox potentials occurred in the foregut and midgut regions, averaging 40 and 110 mV, respectively. Correlation plots between hydrogenase amino acid sequences and 16S rRNA gene sequences indicated that closely related hydrogenases belonged to closely related taxa, whereas distantly related hydrogenases did not necessarily belong to distantly related taxa. Of 178 [FeFe]-hydrogenase gene transcripts, 177 clustered in 12 Clostridiales-affiliated operational taxonomic units, the majority of which were indicative of heretofore unknown hydrogenases. Of 86 group 4 [NiFe]-hydrogenase gene transcripts, 79% and 21% were affiliated with organisms in the Enterobacteriaceae and Aeromonadaceae, respectively. The collective results (i) suggest that fermenters must cope with variable and moderately oxidative redox conditions along the alimentary canal, (ii) demonstrate that heretofore undetected hydrogenases are present in the earthworm gut, and (iii) corroborate previous findings implicating Clostridiaceae and Enterobacteriaceae as active fermentative taxa in earthworm gut content.

  13. Effect of trichloroethylene and tetrachloroethylene on methane oxidation and community structure of methanotrophic consortium.

    PubMed

    Choi, Sun-Ah; Lee, Eun-Hee; Cho, Kyung-Suk

    2013-01-01

    The methane oxidation rate and community structure of a methanotrophic consortium were analyzed to determine the effects of trichloroethylene (TCE) and tetrachloroethylene (PCE) on methane oxidation. The maximum methane oxidation rate (Vmax ) of the consortium was 326.8 μmol·g-dry biomass(-1)·h(-1), and it had a half-saturation constant (Km ) of 143.8 μM. The addition of TCE or PCE resulted in decreased methane oxidation rates, which were decreased from 101.73 to 5.47-24.64 μmol·g-dry biomass(-1)·h(-1) with an increase in the TCE-to-methane ratio, and to 61.95-67.43 μmol·g-dry biomass(-1)·h(-1) with an increase in the PCE-to-methane ratio. TCE and PCE were non-competitive inhibitors for methane oxidation, and their inhibition constants (Ki ) were 33.4 and 132.0 μM, respectively. When the methanotrophic community was analyzed based on pmoA using quantitative real-time PCR (qRT-PCR), the pmoA gene copy numbers were shown to decrease from 7.3 ± 0.7 × 10(8) to 2.1-5.0 × 10(7) pmoA gene copy number · g-dry biomass(-1) with an increase in the TCE-to-methane ratio and to 2.5-7.0 × 10(7) pmoA gene copy number · g-dry biomass(-1) with an increase in the PCE-to-methane ratio. Community analysis by microarray demonstrated that Methylocystis (type II methanotrophs) were the most abundant in the methanotrophic community composition in the presence of TCE. These results suggest that toxic effects caused by TCE and PCE change not only methane oxidation rates but also the community structure of the methanotrophic consortium.

  14. Factors associated with low levels of aerobic fitness among adolescents

    PubMed Central

    Gonçalves, Eliane Cristina de Andrade; Silva, Diego Augusto Santos

    2016-01-01

    Abstract Objective: To evaluate the prevalence of low aerobic fitness levels and to analyze the association with sociodemographic factors, lifestyle and excess body fatness among adolescents of southern Brazil. Methods: The study included 879 adolescents aged 14-19 years the city of São José/SC, Brazil. The aerobic fitness was assessed by Canadian modified test of aerobic fitness. Sociodemographic variables (skin color, age, sex, study turn, economic level), sexual maturation and lifestyle (eating habits, screen time, physical activity, consumption of alcohol and tobacco) were assessed by a self-administered questionnaire. Excess body fatness was evaluated by sum of skinfolds triceps and subscapular. We used logistic regression to estimate odds ratios and 95% confidence intervals. Results: Prevalence of low aerobic fitness level was 87.5%. The girls who spent two hours or more in front screen, consumed less than one glass of milk by day, did not smoke and had an excess of body fatness had a higher chance of having lower levels of aerobic fitness. White boys with low physical activity had had a higher chance of having lower levels of aerobic fitness. Conclusions: Eight out of ten adolescents were with low fitness levels aerobic. Modifiable lifestyle factors were associated with low levels of aerobic fitness. Interventions that emphasize behavior change are needed. PMID:26743851

  15. Multiple roads lead to Rome: combined high-intensity aerobic and strength training vs. gross motor activities leads to equivalent improvement in executive functions in a cohort of healthy older adults.

    PubMed

    Berryman, Nicolas; Bherer, Louis; Nadeau, Sylvie; Lauzière, Séléna; Lehr, Lora; Bobeuf, Florian; Lussier, Maxime; Kergoat, Marie Jeanne; Vu, Thien Tuong Minh; Bosquet, Laurent

    2014-01-01

    The effects of physical activity on cognition in older adults have been extensively investigated in the last decade. Different interventions such as aerobic, strength, and gross motor training programs have resulted in improvements in cognitive functions. However, the mechanisms underlying the relationship between physical activity and cognition are still poorly understood. Recently, it was shown that acute bouts of exercise resulted in reduced executive control at higher relative exercise intensities. Considering that aging is characterized by a reduction in potential energy ([Formula: see text] max - energy cost of walking), which leads to higher relative walking intensity for the same absolute speed, it could be argued that any intervention aimed at reducing the relative intensity of the locomotive task would improve executive control while walking. The objective of the present study was to determine the effects of a short-term (8 weeks) high-intensity strength and aerobic training program on executive functions (single and dual task) in a cohort of healthy older adults. Fifty-one participants were included and 47 (age, 70.7 ± 5.6) completed the study which compared the effects of three interventions: lower body strength + aerobic training (LBS-A), upper body strength + aerobic training (UBS-A), and gross motor activities (GMA). Training sessions were held 3 times every week. Both physical fitness (aerobic, neuromuscular, and body composition) and cognitive functions (RNG) during a dual task were assessed before and after the intervention. Even though the LBS-A and UBS-A interventions increased potential energy to a higher level (Effect size: LBS-A-moderate, UBS-A-small, GMA-trivial), all groups showed equivalent improvement in cognitive function, with inhibition being more sensitive to the intervention. These findings suggest that different exercise programs targeting physical fitness and/or gross motor skills may lead to equivalent improvement in

  16. The relative contribution of methanotrophs to microbial communities and carbon cycling in soil overlying a coal-bed methane seep

    USGS Publications Warehouse

    Mills, Christopher T.; Slater, Gregory F.; Dias, Robert F.; Carr, Stephanie A.; Reddy, Christopher M.; Schmidt, Raleigh; Mandernack, Kevin W.

    2013-01-01

    Seepage of coal-bed methane (CBM) through soils is a potential source of atmospheric CH4 and also a likely source of ancient (i.e. 14C-dead) carbon to soil microbial communities. Natural abundance 13C and 14C compositions of bacterial membrane phospholipid fatty acids (PLFAs) and soil gas CO2 and CH4 were used to assess the incorporation of CBM-derived carbon into methanotrophs and other members of the soil microbial community. Concentrations of type I and type II methanotroph PLFA biomarkers (16:1ω8c and 18:1ω8c, respectively) were elevated in CBM-impacted soils compared with a control site. Comparison of PLFA and 16s rDNA data suggested type I and II methanotroph populations were well estimated and overestimated by their PLFA biomarkers, respectively. The δ13C values of PLFAs common in type I and II methanotrophs were as negative as −67‰ and consistent with the assimilation of CBM. PLFAs more indicative of nonmethanotrophic bacteria had δ13C values that were intermediate indicating assimilation of both plant- and CBM-derived carbon. Δ14C values of select PLFAs (−351 to −936‰) indicated similar patterns of CBM assimilation by methanotrophs and nonmethanotrophs and were used to estimate that 35–91% of carbon assimilated by nonmethanotrophs was derived from CBM depending on time of sampling and soil depth.

  17. The relative contribution of methanotrophs to microbial communities and carbon cycling in soil overlying a coal-bed methane seep.

    PubMed

    Mills, Christopher T; Slater, Gregory F; Dias, Robert F; Carr, Stephanie A; Reddy, Christopher M; Schmidt, Raleigh; Mandernack, Kevin W

    2013-06-01

    Seepage of coal-bed methane (CBM) through soils is a potential source of atmospheric CH4 and also a likely source of ancient (i.e. (14) C-dead) carbon to soil microbial communities. Natural abundance (13) C and (14) C compositions of bacterial membrane phospholipid fatty acids (PLFAs) and soil gas CO2 and CH4 were used to assess the incorporation of CBM-derived carbon into methanotrophs and other members of the soil microbial community. Concentrations of type I and type II methanotroph PLFA biomarkers (16:1ω8c and 18:1ω8c, respectively) were elevated in CBM-impacted soils compared with a control site. Comparison of PLFA and 16s rDNA data suggested type I and II methanotroph populations were well estimated and overestimated by their PLFA biomarkers, respectively. The δ(13) C values of PLFAs common in type I and II methanotrophs were as negative as -67‰ and consistent with the assimilation of CBM. PLFAs more indicative of nonmethanotrophic bacteria had δ(13) C values that were intermediate indicating assimilation of both plant- and CBM-derived carbon. Δ(14) C values of select PLFAs (-351 to -936‰) indicated similar patterns of CBM assimilation by methanotrophs and nonmethanotrophs and were used to estimate that 35-91% of carbon assimilated by nonmethanotrophs was derived from CBM depending on time of sampling and soil depth.

  18. Inflammatory cytokine kinetics to single bouts of acute moderate and intense aerobic exercise in women with active and inactive systemic lupus erythematosus.

    PubMed

    Perandini, L A; Sales-de-Oliveira, D; Mello, Sbv; Camara, N O; Benatti, F B; Lima, F R; Borba, E; Bonfa, E; Roschel, H; Sá-Pinto, A L; Gualano, B

    2015-01-01

    the end of exercise and at the 30th minute of recovery (P<0.05). The SLE(ACTIVE) group also showed higher levels of TNF-α at all time points when compared with the HC group (P<0.05), (except after 90 min, 120 min and 24 hours of recovery) (P>0.05). Importantly, the levels of all cytokine and soluble TNF receptors returned to baseline 24 hours after the end of acute exercise, irrespective of its intensity, in all three groups (P>0.05). This study demonstrated that both the single bouts of acute moderate and intense exercise induced mild and transient changes in cytokine levels in both SLE(INACTIVE) and SLE(ACTIVE) women, providing novel evidence that acute aerobic exercise does not trigger inflammation in patients with this disease.

  19. NADPH:cytochrome c (P450) reductase activates tirapazamine (SR4233) to restore hypoxic and oxic cytotoxicity in an aerobic resistant derivative of the A549 lung cancer cell line

    PubMed Central

    Saunders, M P; Patterson, A V; Chinje, E C; Harris, A L; Stratford, I J

    2000-01-01

    Tirapazamine (TPZ, SR4233, WIN 59075) is a bioreductive drug that is activated in regions of low oxygen tension to a cytotoxic radical intermediate. This labile metabolite shows high selective toxicity towards hypoxic cells, such as those found in solid tumours. Under aerobic conditions, redox cycling occurs with subsequent generation of superoxide radicals, which are also cytotoxic. NADPH:cytochrome c (P450) reductase (P450R) is a one-electron reducing enzyme that efficiently activates TPZ. Recently a derivative of the A549 non-small cell lung cancer cell line (A549c50) was generated that showed substantially reduced P450R activity compared to its parental line (Elwell et al (1997) Biochem Pharmacol54: 249–257). Here, it is demonstrated that the A549c50 cells are markedly more resistant to TPZ under both aerobic and hypoxic conditions. In addition, these cells have a dramatically impaired ability to metabolize TPZ to its two-electron reduction product, SR4317, under hypoxic conditions when compared to wild-type cells. P450R activity in the A549c50 cells was reintroduced to similar levels as that seen in the parental A549 cells by transfection of the full-length cDNA for human P450R. These P450R over-expressing cells exhibit restored sensitivity to TPZ under both aerobic and hypoxic conditions, comparable to that found in the original parental A549 cells. Further, the ability of the transfected cells to metabolize TPZ to SR4317 under hypoxic conditions is also shown to be restored. This provides further evidence that P450R can play an important role in the activation, metabolism and toxicity of this lead bioreductive drug. © 2000 Cancer Research Campaign PMID:10682679

  20. Effects of Long-Term CO2 Enrichment on Soil-Atmosphere CH4 Fluxes and the Spatial Micro-Distribution of Methanotrophic Bacteria

    PubMed Central

    Karbin, Saeed; Guillet, Cécile; Kammann, Claudia I.; Niklaus, Pascal A.

    2015-01-01

    Background Effects of elevated atmospheric CO2 concentrations on plant growth and associated C cycling have intensively been studied, but less is known about effects on the fluxes of radiatively active trace gases other than CO2. Net soil-atmosphere CH4 fluxes are determined by the balance of soil microbially-driven methane (CH4) oxidation and methanogenesis, and both might change under elevated CO2. Methods and Results Here, we studied CH4 dynamics in a permanent grassland exposed to elevated CO2 for 14 years. Soil-atmosphere fluxes of CH4 were measured using large static chambers, over a period of four years. The ecosystem was a net sink for atmospheric CH4 for most of the time except summer to fall when net CH4 emissions occurred. We did not detect any elevated CO2 effects on CH4 fluxes, but emissions were difficult to quantify due to their discontinuous nature, most likely because of ebullition from the saturated zone. Potential methanotrophic activity, determined by incubation of fresh sieved soil under standardized conditions, also did not reveal any effect of the CO2 treatment. Finally, we determined the spatial micro-distribution of methanotrophic activity at less than 5× atmospheric (10 ppm) and elevated (10000 ppm) CH4 concentrations, using a novel auto-radiographic technique. These analyses indicated that domains of net CH4 assimilation were distributed throughout the analyzed top 15 cm of soils, with no dependence on CH4 concentration or CO2 treatment. Conclusions Our investigations suggest that elevated CO2 exerts no or only minor effects on CH4 fluxes in the type of ecosystem we studied, at least as long as soil moisture differences are small or absent as was the case here. The autoradiographic analyses further indicate that the spatial niche of CH4 oxidation does not shift in response to CO2 enrichment or CH4 concentration, and that the same type of methanotrophs may oxidize CH4 from atmospheric and soil-internal sources. PMID:26147694

  1. Variable carbon isotope fractionation expressed by aerobic CH 4-oxidizing bacteria

    NASA Astrophysics Data System (ADS)

    Templeton, Alexis S.; Chu, Kung-Hui; Alvarez-Cohen, Lisa; Conrad, Mark E.

    2006-04-01

    Carbon isotope fractionation factors reported for aerobic bacterial oxidation of CH 4(α) range from 1.003 to 1.039. In a series of experiments designed to monitor changes in the carbon isotopic fractionation of CH 4 by Type I and Type II methanotrophic bacteria, we found that the magnitude of fractionation was largely due to the first oxidation step catalyzed by methane monooxygenase (MMO). The most important factor that modulates the (α) is the fraction of the total CH 4 oxidized per unit time, which strongly correlates to the cell density of the growth cultures under constant flow conditions. At cell densities of less than 0.1 g/L, fractionation factors greater than 1.03 were observed, whereas at cell densities greater than 0.5 g/L the fractionation factors decreased to as low as 1.002. At low cell densities, low concentrations of MMO limit the amount of CH 4 oxidized, while at higher cell densities, the overall rates of CH 4 oxidation increase sufficiently that diffusion of CH 4 from the gaseous to dissolved state and into the cells is likely the rate-determining step. Thus, the residual CH 4 is more fractionated at low cell densities, when only a small fraction of the total CH 4 has been oxidized, than at high cell densities, when up to 40% of the influent CH 4 has been utilized. Therefore, since Rayleigh distillation behavior is not observed, δ 13C values of the residual CH 4 cannot be used to infer the amount oxidized in either laboratory or field-studies. The measured (α) was the same for both Type I and Type II methanotrophs expressing particulate or soluble MMO. However, large differences in the δ 13C values of biomass produced by the two types of methanotrophs were observed. Methylosinus trichosporium OB3b (Type II) produced biomass with δ 13C values about 15‰ higher than the dissimilated CO 2, whereas Methylomonas methanica (Type I) produced biomass with δ 13C values only about 6‰ higher than the CO 2. These effects were independent of the

  2. Physical activity, aerobic fitness and parental socio-economic position among adolescents: the German Health Interview and Examination Survey for Children and Adolescents 2003–2006 (KiGGS)

    PubMed Central

    2014-01-01

    Background The positive association between parental socio-economic position (PSEP) and health among adolescents may be partly explained by physical activity behaviour. We investigated the associations between physical activity, aerobic fitness and PSEP in a population based sample of German adolescents. Methods 5,251 participants, aged 11–17 years, in the German Health Interview and Examination Survey for Children and Adolescents 2003–2006 (KiGGS) underwent a sub-maximal cycle ergometer test and completed a questionnaire obtaining information on physical activity and media use. The associations between physical activity, media use, aerobic fitness and PSEP were analysed with multivariate logistic regression models for boys and girls separately. Odds ratios (ORs) of PSEP (education, occupation and income) on the outcomes were calculated adjusted for age, region, and other influencing factors. Results Parental education was more strongly associated with the outcome variables than parental occupation and income. After adjusting for age and region, a higher parental education level was associated with better aerobic fitness – with an OR of 1.5 (95% CI 1.2-1.9) for girls whose parents had secondary education and 1.9 (1.4-2.5) for girls whose parents had tertiary education compared to girls whose parents had primary education. The corresponding ORs for boys were 1.3 (1.0-1.6) and 1.6 (1.2-2.1), respectively. Higher parental education level was associated with lower media use: an OR of 2.1 (1.5-3.0) for girls whose parents had secondary education and 2.7 (1.8-4.1) for girls whose parents had primary education compared to girls whose parents had tertiary education. The corresponding ORs for boys were 1.5 (1.2-1.9) and 1.9 (1.5-2.5), respectively. Higher parental education level was associated with a higher physical activity level only among girls: an OR of 1.3 (1.0-1.6) for girls whose parents had secondary education and 1.2 (0.9-1.5) for girls whose parents had

  3. 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.

  4. Identification of Methanotrophic Lipid Biomarkers in Cold-Seep Mussel Gills: Chemical and Isotopic Analysis

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda L.; Summons, Roger E.; Dowling, Lesley M.; Zahiralis, Karen D.

    1995-01-01

    A lipid analysis of the tissues of a cold-seep mytilid mussel collected from the Louisiana slope of the Gulf of Mexico was used in conjunction with a compound-specific isotope analysis to demonstrate the presence of methanotrophic symbionts in the mussel gill tissue and to demonstrate the host's dependence on bacterially synthesized metabolic intermediates. The gill tissue contained large amounts of group-specific methanotrophic biomarkers, bacteriohopanoids, 4-methylsterols, lipopolysaccharide-associated hydroxy fatty acids, and type I-specific 16:1 fatty acid isomers with bond positions at delta-8, delta-10, and delta-ll. Only small amounts of these compounds were detected in the mantle or other tissues of the host animal. A variety of cholesterol and 4-methylsterol isomers were identified as both free and steryl esters, and the sterol double bond positions suggested that the major bacterially derived gill sterol(11.0% 4(alpha)-methyl-cholesta-8(14), 24-dien-3(beta)-ol) was converted to host cholesterol (64.2% of the gill sterol was cholest-5-en-3(beta)-ol). The stable carbon isotope values for gill and mantle preparations were, respectively, -59.0 and -60.4 per thousand for total tissue, -60.6 and -62.4 per thousand for total lipids, -60.2 and -63.9 per thousand for phospholipid fatty acids, and -71.8 and -73.8 per thousand for sterols. These stable carbon isotope values revealed that the relative fractionation pattern was similar to the patterns obtained in pure culture experiments with methanotrophic bacteria further supporting the conversion of the bacterial methyl-sterol pool.

  5. Phosphoketolase overexpression increases biomass and lipid yield from methane in an obligate methanotrophic biocatalyst.

    PubMed

    Henard, Calvin A; Smith, Holly K; Guarnieri, Michael T

    2017-04-01

    Microbial conversion of methane to high-value bio-based chemicals and materials offers a path to mitigate GHG emissions and valorize this abundant-yet -underutilized carbon source. In addition to fermentation optimization strategies, rational methanotrophic bacterial strain engineering offers a means to reach industrially relevant titers, carbon yields, and productivities of target products. The phosphoketolase pathway functions in heterofermentative bacteria where carbon flux through two sugar catabolic pathways to mixed acids (lactic acid and acetic acid) increases cellular ATP production. Importantly, this pathway also serves as an alternative route to produce acetyl-CoA that bypasses the CO2 lost through pyruvate decarboxylation in the Embden-Meyerhof-Parnas pathway. Thus, the phosphoketolase pathway can be leveraged for carbon efficient biocatalysis to acetyl-CoA-derived intermediates and products. Here, we show that the industrially promising methane biocatalyst, Methylomicrobium buryatense, encodes two phosphoketolase isoforms that are expressed in methanol- and methane-grown cells. Overexpression of the PktB isoform led to a 2-fold increase in intracellular acetyl-CoA concentration, and a 2.6-fold yield enhancement from methane to microbial biomass and lipids compared to wild-type, increasing the potential for methanotroph lipid-based fuel production. Off-gas analysis and metabolite profiling indicated that global metabolic rearrangements, including significant increases in post-translational protein acetylation and gene expression of the tetrahydromethanopterin-linked pathway, along with decreases in several excreted products, coincided with the superior biomass and lipid yield observed in the engineered strain. Further, these data suggest that phosphoketolase may play a key regulatory role in methanotrophic bacterial metabolism. Given that acetyl-CoA is a key intermediate in several biosynthetic pathways, phosphoketolase overexpression offers a viable

  6. Bioreactor Performance Parameters for an Industrially-Promising Methanotroph Methylomicrobium buryatense 5GB1

    DOE PAGES

    Gilman, Alexey; Laurens, Lieve M.; Puri, Aaron W.; ...

    2015-11-16

    Methane is a feedstock of interest for the future, both from natural gas and from renewable biogas sources. Methanotrophic bacteria have the potential to enable commercial methane bioconversion to value-added products such as fuels and chemicals. A strain of interest for such applications is Methylomicrobium buryatense 5GB1, due to its robust growth characteristics. But, to take advantage of the potential of this methanotroph, it is important to generate comprehensive bioreactor-based datasets for different growth conditions to compare bioprocess parameters. The datasets of growth parameters, gas utilization rates, and products (total biomass, extracted fatty acids, glycogen, excreted acids) were obtained formore » cultures of M. buryatense 5GB1 grown in continuous culture under methane limitation and O2 limitation conditions. Additionally, experiments were performed involving unrestricted batch growth conditions with both methane and methanol as substrate. All four growth conditions show significant differences. The most notable changes are the high glycogen content and high formate excretion for cells grown on methanol (batch), and high O2:CH4 utilization ratio for cells grown under methane limitation. The results presented here represent the most comprehensive published bioreactor datasets for a gamma-proteobacterial methanotroph. This information shows that metabolism by M. buryatense 5GB1 differs significantly for each of the four conditions tested. O2 limitation resulted in the lowest relative O2 demand and fed-batch growth on methane the highest. Future studies are needed to understand the metabolic basis of these differences. However, these results suggest that both batch and continuous culture conditions have specific advantages, depending on the product of interest.« less

  7. Bioreactor Performance Parameters for an Industrially-Promising Methanotroph Methylomicrobium buryatense 5GB1

    SciTech Connect

    Gilman, Alexey; Laurens, Lieve M.; Puri, Aaron W.; Chu, Frances; Pienkos, Philip T.; Lidstrom, Mary E.

    2015-11-16

    Methane is a feedstock of interest for the future, both from natural gas and from renewable biogas sources. Methanotrophic bacteria have the potential to enable commercial methane bioconversion to value-added products such as fuels and chemicals. A strain of interest for such applications is Methylomicrobium buryatense 5GB1, due to its robust growth characteristics. But, to take advantage of the potential of this methanotroph, it is important to generate comprehensive bioreactor-based datasets for different growth conditions to compare bioprocess parameters. The datasets of growth parameters, gas utilization rates, and products (total biomass, extracted fatty acids, glycogen, excreted acids) were obtained for cultures of M. buryatense 5GB1 grown in continuous culture under methane limitation and O2 limitation conditions. Additionally, experiments were performed involving unrestricted batch growth conditions with both methane and methanol as substrate. All four growth conditions show significant differences. The most notable changes are the high glycogen content and high formate excretion for cells grown on methanol (batch), and high O2:CH4 utilization ratio for cells grown under methane limitation. The results presented here represent the most comprehensive published bioreactor datasets for a gamma-proteobacterial methanotroph. This information shows that metabolism by M. buryatense 5GB1 differs significantly for each of the four conditions tested. O2 limitation resulted in the lowest relative O2 demand and fed-batch growth on methane the highest. Future studies are needed to understand the metabolic basis of these differences. However, these results suggest that both batch and continuous culture conditions have specific advantages, depending on the product of interest.

  8. Use of gene probes to assess the impact and effectiveness of aerobic in situ bioremediation of TCE

    SciTech Connect

    Hazen, Terry C.; Chakraborty, Romy; Fleming, James M.; Gregory, Ingrid R.; Bowman, John P.; Jimenez, Luis; Zhang, Dai; Pfiffner, Susan M.; Brockman, Fred J.; Sayler, Gary S.

    2009-03-15

    Gene probe hybridization was used to determine distribution and expression of co-metabolic genes at a contaminated site as it underwent in situ methanotrophic bioremediation of trichloroethylene (TCE). The bioremediation strategies tested included a series of air, air:methane, and air:methane:nutrient pulses of the test plot using horizontal injection wells. During the test period, the levels of TCE reduced drastically in almost all test samples. Sediment core samples (n = 367) taken from 0 m (surface)-43 m depth were probed for gene coding for methanotrophic soluble methane monooxygenase (sMMO) and heterotrophic toluene dioxygenase (TOD), which are known to co-metabolize TCE. The same sediment samples were also probed for genes coding for methanol dehydrogenase (MDH) (catalyzing the oxidation of methanol to formaldehyde) to assess specifically changes in methylotrophic bacterial populations in the site. Gene hybridization results showed that the frequency of detection of sMMO genes were stimulated approximately 250% following 1% methane:air (v/v) injection. Subsequent injection of 4% methane:air (v/v) resulted in an 85% decline probably due to nutrient limitations, since addition of nutrients (gaseous nitrogen and phosphorus) thereafter caused an increase in the frequency of detection of sMMO genes. Detection of TOD genes declined during the process, and eventually they were non-detectable by the final treatment, suggesting that methanotrophs displaced the TOD gene containing heterotrophs. Active transcription of sMMO and TOD was evidenced by hybridization to mRNA. These analyses combined with results showing the concomitant decline in TCE concentrations, increases in chloride concentration and increases in methanotroph viable counts, provide multiple lines of evidence that TCE remediation was caused specifically by methanotrophs. Our results suggest that sMMO genes are responsible for most, if not all, of the observed biodegradation of TCE. This study

  9. Aerobic landfill bioreactor

    SciTech Connect

    Hudgins, Mark P; Bessette, Bernard J; March, John; McComb, Scott T.

    2000-01-01

    The present invention includes a method of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120.degree. F. and 140.degree. F. in steady state.

  10. Aerobic landfill bioreactor

    SciTech Connect

    Hudgins, Mark P; Bessette, Bernard J; March, John C; McComb, Scott T.

    2002-01-01

    The present invention includes a system of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120.degree. F. and 140.degree. F. in steady state.

  11. Aerobic landfill bioreactor

    SciTech Connect

    Hudgins, M.P.; Bessette, B.J.; March, J.; McComb, S.T.

    2000-02-15

    The present invention includes a method of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120 F and 140 F in steady state.

  12. Aerobic fitness testing: an update.

    PubMed

    Stevens, N; Sykes, K

    1996-12-01

    This study confirms that all three tests are reliable tools for the assessment of cardiorespiratory fitness and the prediction of aerobic capacity. While this particular study consisted of active, youthful subjects, subsequent studies at University College Chester have found similar findings with larger databases and a wider cross-section of subjects. The Astrand cycle test and Chester step test are submaximal tests with error margins of 5-15 per cent and therefore, not as precise as maximal testing. However, they still give a reasonably accurate reflection of an individual's fitness without the cost, time, effort and risk on the part of the subject. The bleep test is a low-cost maximal test designed for well-motivated, active individuals who are used to running to physical exhaustion. Used on other groups, results will not accurately reflect cardiorespiratory fitness values. While all three tests have inherent advantages and disadvantages, perhaps the most important factors are the knowledge and skills of the tester. Without a sound understanding of the physiological principles underlying these tests, and the ability to conduct an accurate assessment and evaluation of results in a knowledgeable and meaningful way, then the credibility of the tests and the results become suspect. However, used correctly, aerobic capacity tests can provide valuable baseline data about the fitness levels of individuals and data from which exercise programmes may be developed. The tests also enable fitness improvements to be monitored, help to motivate participants by establishing reasonable and achievable goals, assist in risk stratification and facilitate participants' education about the importance of physical fitness for work and for life. Since this study was completed, further tests have been repeated on 140 subjects of a wider age and ability range. This large database confirms the results found in this study.

  13. Variants of the obligate methanotroph isolate 761M capable of growth on glucose in the absence of methane

    SciTech Connect

    Zhao, S.J.; Hanson, R.S.

    1984-10-01

    Isolate 761M is an unusual type I methanotroph that possess a complete tricarboxylic acid cycle. Variants of this methanotroph that were capable of growth with methanol (isolate 761AR) or glucose (isolate 761H) have been isolated. Cultures of isolate 761H grown with glucose and casein hydrolysate as the sole carbon and energy sources retained the ability to grow on methane, contained methane monooxygenase and 3-hexulose phosphate synthase, and possessed intracytoplasmic membranes similar to those found in thin sections of isolate 761M grown on methane. Methane monooxygenase was also present in cultures of isolate 761AR grown on methanol and casein hydrolysate. 18 references, 4 figures, 2 tables.

  14. Physiology, biochemistry, and specific inhibitors of CH4, NH4+, and CO oxidation by methanotrophs and nitrifiers.

    PubMed Central

    Bédard, C; Knowles, R

    1989-01-01

    Ammonia oxidizers (family Nitrobacteraceae) and methanotrophs (family Methylococcaceae) oxidize CO and CH4 to CO2 and NH4+ to NO2-. However, the relative contributions of the two groups of organisms to the metabolism of CO, CH4, and NH4+ in various environments are not known. In the ammonia oxidizers, ammonia monooxygenase, the enzyme responsible for the conversion of NH4+ to NH2OH, also catalyzes the oxidation of CH4 to CH3OH. Ammonia monooxygenase also mediates the transformation of CH3OH to CO2 and cell carbon, but the pathway by which this is done is not known. At least one species of ammonia oxidizer, Nitrosococcus oceanus, exhibits a Km for CH4 oxidation similar to that of methanotrophs. However, the highest rate of CH4 oxidation recorded in an ammonia oxidizer is still five times lower than rates in methanotrophs, and ammonia oxidizers are apparently unable to grow on CH4. Methanotrophs oxidize NH4+ to NH2OH via methane monooxygenase and NH4+ to NH2OH via methane monooxygenase and NH2OH to NO2- via an NH2OH oxidase which may resemble the enzyme found in ammonia oxidizers. Maximum rates of NH4+ oxidation are considerably lower than in ammonia oxidizers, and the affinity for NH4+ is generally lower than in ammonia oxidizers. NH4+ does not apparently support growth in methanotrophs. Both ammonia monooxygenase and methane monooxygenase oxidize CO to CO2, but CO cannot support growth in either ammonia oxidizers or methanotrophs. These organisms have affinities for CO which are comparable to those for their growth substrates and often higher than those in carboxydobacteria. The methane monooxygenases of methanotrophs exist in two forms: a soluble form and a particulate form. The soluble form is well characterized and appears unrelated to the particulate. Ammonia monooxygenase and the particulate methane monooxygenase share a number of similarities. Both enzymes contain copper and are membrane bound. They oxidize a variety of inorganic and organic compounds, and

  15. Methanotrophic diversity in high arctic wetlands on the islands of Svalbard (Norway)--denaturing gradient gel electrophoresis analysis of soil DNA and enrichment cultures.

    PubMed

    Wartiainen, Ingvild; Hestnes, Anne Grethe; Svenning, Mette M

    2003-10-01

    The methanotrophic community in arctic soil from the islands of Svalbard, Norway (78 degrees N) was analysed by combining group-specific PCR with PCR of the highly variable V3 region of the 16S rRNA gene and then by denaturing gradient gel electrophoresis (DGGE). Selected bands were sequenced for identification. The analyses were performed with DNA extracted directly from soil and from enrichment cultures at 10 and 20 degrees C. The two genera Methylobacter and Methylosinus were found in all localities studied. The DGGE band patterns were simple, and DNA fragments with single base differences were separated. The arctic tundra is a potential source of extensive methane emission due to climatic warming because of its large reservoirs of stored organic carbon. Higher temperatures due to climatic warming can cause increased methane production, and the abundance and activity of methane-oxidizing bacteria in the arctic soil may be important regulators for methane emission to the atmosphere.

  16. Aerobic and two-stage anaerobic-aerobic sludge digestion with pure oxygen and air aeration.

    PubMed

    Zupancic, Gregor D; Ros, Milenko

    2008-01-01

    The degradability of excess activated sludge from a wastewater treatment plant was studied. The objective was establishing the degree of degradation using either air or pure oxygen at different temperatures. Sludge treated with pure oxygen was degraded at temperatures from 22 degrees C to 50 degrees C while samples treated with air were degraded between 32 degrees C and 65 degrees C. Using air, sludge is efficiently degraded at 37 degrees C and at 50-55 degrees C. With oxygen, sludge was most effectively degraded at 38 degrees C or at 25-30 degrees C. Two-stage anaerobic-aerobic processes were studied. The first anaerobic stage was always operated for 5 days HRT, and the second stage involved aeration with pure oxygen and an HRT between 5 and 10 days. Under these conditions, there is 53.5% VSS removal and 55.4% COD degradation at 15 days HRT - 5 days anaerobic, 10 days aerobic. Sludge digested with pure oxygen at 25 degrees C in a batch reactor converted 48% of sludge total Kjeldahl nitrogen to nitrate. Addition of an aerobic stage with pure oxygen aeration to the anaerobic digestion enhances ammonium nitrogen removal. In a two-stage anaerobic-aerobic sludge digestion process within 8 days HRT of the aerobic stage, the removal of ammonium nitrogen was 85%.

  17. Considerations in prescribing preflight aerobic exercise for astronauts

    NASA Technical Reports Server (NTRS)

    Frey, Mary Anne Bassett

    1987-01-01

    The physiological effects of prolonged exposure to weightlessness are discussed together with the effects of aerobic exercise on human characteristics affected by weightlessness. It is noted that, although early data on orthostatic intolerance after spaceflight led to a belief that a high level of aerobic fitness for astronauts was detrimental to orthostatic tolerance on return to earth, most of the data available today do not suport this contention. Aerobic fitness was found to be beneficial to cardiovascular function and to mental performance; therefore, it may be important in performing extravehicular activities during flight.

  18. Sludge minimization using aerobic/anoxic treatment technology

    SciTech Connect

    Mines, R.O. Jr.; Kalch, R.S.

    1999-07-01

    The objective of this investigation was to demonstrate through a bench-scale study that using an aerobic/anoxic sequence to treat wastewater and biosolids could significantly reduce the production of biosolids (sludge). A bench-scale activated sludge reactor and anoxic digester were operated for approximately three months. The process train consisted of a completely-mixed aerobic reactor with wasting of biosolids to an anoxic digester for stabilization. The system was operated such that biomass produced in the aerobic activated sludge process was wasted to the anoxic digester; and biomass produced in the anoxic digester was wasted back to the activated sludge process. A synthetic wastewater consisting of bacto-peptone nutrient broth was fed to the liquid process train. Influent and effluent to the aerobic biological process train were analytically tested, as were the contents of mixed liquor in the aerobic reactor and anoxic digester. Overall removal efficiencies for the activated sludge process with regard to COD, TKN, NH{sub 3}-N, and alkalinity averaged 91, 89, 98, and 38%, respectively. The overall average sludge production for the aerobic/anoxic process was 24% less than the overall average sludge production from a conventional activated sludge bench-scale system fed the same substrate and operated under similar mean cell residence times.

  19. Effects of nutrient dosing on subsurface methanotrophic populations and trichloroethylene degradation.

    PubMed

    Pfiffner, S M; Palumbo, A V; Phelps, T J; Hazen, T C

    1997-01-01

    In in situ bioremediation demonstration at the Savannah River Site in Aiken, South Carolina, trichloroethyle degrading microorganisms were stimulated by delivering nutrients to the TCE-contaminated subsurface via horizontal injection wells. Microbial and chemical monitoring of groundwater from 12 vertical wells was used to examine the effects of methane and nutrient (nitrogen and phosphorus) dosing on the methanotrophic populations and on the potential of the subsurface microbial communities to degrade TCE. Densities of methanotrophs increased 3-5 orders of magnitude during the methane- and nutrient-injection phases; this increase coinclded with the higher methane levels observed in the monitoring wells. TCE degradation capacity, although not directly tied to methane concentration, responded to the methane injection, and responded more dramatically to the multiple-nutrient injection. tion. These results support the crucial role of methane, nitrogen, and phosphorus as amended nutrients in TCE bioremediation. The enhancing effects of nutrient dosing on microbial abundance and degradative potentials, coupled with increased chloride concentrations, provided multiple lines of evidence substantiating the effectiveness of this integrated in situ bioremediation process.

  20. Diversity of functional genes of methanogens, methanotrophs and sulfate reducers in deep-sea hydrothermal environments.

    PubMed

    Nercessian, Olivier; Bienvenu, Nadège; Moreira, David; Prieur, Daniel; Jeanthon, Christian

    2005-01-01

    To contribute to the identification of methanogens, methanotrophs and sulfate-reducing bacteria (SRB) in microbial communities from the 13 degrees N (East Pacific Rise) and Rainbow (Mid-Atlantic Ridge) hydrothermal vent fields, we investigated the diversity of mcrA, pmoA and dsrAB genes sequences. Clone libraries were obtained using DNA isolated from fragments of diffuse vents, sediment and in situ samplers. The clones were categorized by restriction fragment length polymorphism, and representatives of each group were sequenced. Sequences were related to that of hyperthermophilic (order Methanopyrales and family Methanocaldococcaceae), thermophilic and mesophilic (family Methanococcaceae) methanogens, thermophilic (proposed genus 'Methylothermus') and mesophilic type I methanotrophs, and hyperthermophilic (order Archaeoglobales), thermophilic (order Thermodesulfobacteriales) and mesophilic (family Desulfobulbaceae) SRB. Several of the obtained sequences were distantly related to the genes of cultivated organisms, providing evidence of the existence of novel lineages in the three functional groups. This study provides for the first time an insight into the diversity of several functional genes of deep-sea hydrothermal system microorganisms.

  1. Characterization and phylogeny of a novel methanotroph, Methyloglobulus morosus gen. nov., spec. nov.

    PubMed

    Deutzmann, J S; Hoppert, M; Schink, B

    2014-05-01

    A novel methanotrophic gammaproteobacterium, strain KoM1, was isolated from the profundal sediment of Lake Constance after initial enrichment in opposing gradients of methane and oxygen. Strain KoM1 grows on methane or methanol as its sole source of carbon and energy. It is a Gram-negative methanotroph, often expressing red pigmentation. Cells are short rods and occur sometimes in pairs or short chains. Strain KoM1 grows preferably at reduced oxygen concentrations (pO2=0.05-0.1bar). It can fix nitrogen, and grows at neutral pH and at temperatures between 4 and 30°C. Phylogenetically, the closest relatives are Methylovulum miyakonense and Methylosoma difficile showing 91% 16S rRNA gene sequence identity. The only respiratory quinone is ubiquinone Q8; the main polar lipids are phosphatidyl ethanolamine and phosphatidyl glycerol. The major cellular fatty acids are summed feature 3 (presumably C16:1ω7c) and C16:1ω5c, and the G+C content of the DNA is 47.7mol%. Strain KoM1 is described as the type strain of a novel species within a new genus, Methyloglobulus morosus gen. nov., sp. nov.

  2. Effects of toxicity, aeration, and reductant supply on trichloroethylene transformation by a mixed methanotrophic culture

    SciTech Connect

    Alvarez-Cohen, L. ); McCarty, P.L. )

    1991-01-01

    The trichloroethylene (TCE) transformation rate and capacity of a mixed methanotrophic culture at room temperature were measured to determine the effects of time without methane (resting), use of an alternative energy source (formate), aeration, and toxicity of TCE and its transformation products. The initial specific TCE transformation rate of resting cells was 0.6 mg of TCE per mg of cells per day, and they had a finite TCE transformation capacity of 0.036 mg of TCE per mg of cells. Formate addition resulted in increased initial specific TCE transformation rates (2.1 mg/mg of cells per day) and elevated transformation capacity (0.073 mg of TCE per mg of cells). Significant declines in methane conversion rates following exposure to TCE were observed for both resting and formate-fed cells, suggesting toxic effects caused by TCE or its transformation products. TCE transformation and methane consumption rates of resting cells decreased with time much more rapidly when cells were shaken and aerated than when they remained dormant, suggesting that the transformation ability of methanotrophs is best preserved by storage under anoxic conditions.

  3. Assimilation of Inorganic Nitrogen by Marine Invertebrates and Their Chemoautotrophic and Methanotrophic Symbionts

    PubMed Central

    Lee, Raymond W.; Childress, James J.

    1994-01-01

    Symbioses between marine invertebrates and their chemoautotrophic and methanotrophic symbionts are now known to exist in a variety of habitats where reduced chemical species are present. The utilization of chemical energy and reliance on C1 compounds by these symbioses are well documented. Much less is known about their metabolism of nitrogen. Earlier work has shown that the tissues of organisms in these associations are depleted of 15N compared with those of other marine organisms, indicating that local sources of nitrogen are assimilated and that novel mechanisms of nitrogen metabolism may be involved. Although these symbioses have access to rich sources of ammonium (NH4+ and NH3) and/or nitrate, several investigators have proposed that N2 fixation may account for some of these isotope values. Here we report that [15N]ammonium and, to a lesser degree, [15N]nitrate are assimilated into organic compounds by Solemya reidi, a gutless clam containing S-oxidizing bacteria, and seep mussel Ia, an undescribed mytilid containing methanotrophic bacteria. In contrast, Riftia pachyptila, the giant hydrothermal vent tube worm symbiotic with S-oxidizing bacteria, assimilated nitrate but not exogenous ammonium. The rates of assimilation of these sources are sufficient to at least partially support C1 compound metabolism. N2 assimilation was not exhibited by the symbionts tested. PMID:16349279

  4. Rare earth metals are essential for methanotrophic life in volcanic mudpots.

    PubMed

    Pol, Arjan; Barends, Thomas R M; Dietl, Andreas; Khadem, Ahmad F; Eygensteyn, Jelle; Jetten, Mike S M; Op den Camp, Huub J M

    2014-01-01

    Growth of Methylacidiphilum fumariolicum SolV, an extremely acidophilic methanotrophic microbe isolated from an Italian volcanic mudpot, is shown to be strictly dependent on the presence of lanthanides, a group of rare earth elements (REEs) such as lanthanum (Ln), cerium (Ce), praseodymium (Pr) and neodymium (Nd). After fractionation of the bacterial cells and crystallization of the methanol dehydrogenase (MDH), it was shown that lanthanides were essential as cofactor in a homodimeric MDH comparable with one of the MDHs of Methylobacterium extorquens AM1. We hypothesize that the lanthanides provide superior catalytic properties to pyrroloquinoline quinone (PQQ)-dependent MDH, which is a key enzyme for both methanotrophs and methylotrophs. Thus far, all isolated MxaF-type MDHs contain calcium as a catalytic cofactor. The gene encoding the MDH of strain SolV was identified to be a xoxF-ortholog, phylogenetically closely related to mxaF. Analysis of the protein structure and alignment of amino acids showed potential REE-binding motifs in XoxF enzymes of many methylotrophs, suggesting that these may also be lanthanide-dependent MDHs. Our findings will have major environmental implications as metagenome studies showed (lanthanide-containing) XoxF-type MDH is much more prominent in nature than MxaF-type enzymes.

  5. Earthworm cast as a promising filter bed material and its methanotrophic contribution to methane removal.

    PubMed

    Moon, Kyung-Eun; Lee, Soo-Yeon; Lee, Sang Hyon; Ryu, Hee Wook; Cho, Kyung-Suk

    2010-04-15

    The use of biocovers is a promising strategy toward mitigating CH(4) emission from smaller and/or older landfills. In this study, a filter bed material consisting of a mixture of earthworm cast and rice paddy soil in a biocover was evaluated. Although the CH(4) oxidation rate of the enriched paddy soil was 4.9 microg g-dry soil(-1) h(-1), it was enhanced to 25.1 microg g-dry soil(-1) h(-1) by adding an earthworm cast with a 3:7 ratio of earthworm cast:soil (wet weight). CO(2) was found as the final oxidation product of CH(4), and the mole ratio of CO(2) production to CH(4) consumption was 0.27. At a moisture content range of 15-40% and a temperature range of 20-40 degrees C, the CH(4) oxidation rates of the enriched mixture were more than 57% of the maximum rate obtained at 25% moisture content and 25 degrees C. By denaturing gradient gel electrophoresis analysis employing primers for the universal bacterial 16S rRNA gene, and terminal-restriction fragment length polymorphism analysis using primers for the pmoA gene, the bacterial and methanotrophic communities in the enriched mixture were mainly originate from paddy soil and earthworm cast, respectively. Both type I (mainly Methylocaldum) and type II methanotrophs (mainly Methylocystis) played important roles in CH(4) oxidation in the enriched mixture.

  6. Molecular characterization of a deep-sea methanotrophic mussel symbiont that carries a RuBisCO gene.

    PubMed

    Elsaied, Hosam Easa; Kaneko, Ryo; Naganuma, Takeshi

    2006-01-01

    In our previous investigation on the genes of 1,5-ribulose bisphosphate carboxylase/oxygenase (RuBisCO; EC 4.1.1.39) in deep-sea chemoautotrophic and methanotrophic endosymbioses, the gene encoding the large subunit of RuBisCO form I (cbbL) had been detected in the gill of a mussel belonging to the genus Bathymodiolus from a western Pacific back-arc hydrothermal vent. This study further examined the symbiont source of the RuBisCO cbbL gene along with the genes of 16S ribosomal RNA (16S rDNA) and particulate methane monooxygenase (EC 1.14.13.25; pmoA) and probed for the presence of the ATP sulfurylase gene (EC 2.7.7.4; sopT). The 16S rDNA sequence analysis indicated that the mussel harbors a monospecific methanotrophic Gammaproteobacterium. This was confirmed by amplification and sequencing of the methanotrophic pmoA, while thiotrophic sopT was not amplified from the same symbiotic genome DNA. Fluorescence in situ hybridization demonstrated simultaneous occurrence of the symbiont-specific 16S rDNA, cbbL and pmoA, but not sopT, in the mussel gill. This is the first molecular and visual evidence for a methanotrophic bacterial endosymbiont that bears the RuBisCO cbbL gene relevant to autotrophic CO(2) fixation.

  7. Selection of Type I and Type II Methanotrophic Proteobacteria in a Fluidized Bed Reactor under Non-Sterile Conditions

    DTIC Science & Technology

    2011-08-01

    2009). Polyhydroxyalkanoates (PHAs), which can be used as bioplastics (Reddy et al., 2003), are intracellular granules that accumulate in some bacteria...of methanotrophs in lake sediments. Appl. Environ. Microb. 65, 5066–5074. DiGregorio, B., 2009. Biobased performance bioplastic : mirel. Chem. Biol

  8. EMERGING TECHNOLOGY SUMMARY: PILOT-SCALE DEMONSTRATION OF A TWO-STAGE METHANOTROPHIC BIOREACTOR FOR BIODEGRADATION OF TRICHLOROETHENE IN GROUNDWATER

    EPA Science Inventory

    BioTrol, Inc., developed a two-stage, methanotrophic, bioreactor system for remediation of water contaminated with trichloroethylene (TCE) and other chlorinated, volatile, aliphatic hydrocarbons. The first stage was a suspended-growth culture vessel with a bubbleless methane tran...

  9. Isolation of methanotrophic bacteria from a london landfill: a preliminary study using molecular and stable isotopic techniques.

    NASA Astrophysics Data System (ADS)

    Sriskantharajah, S.; Cutting, S.; Lowry, D.; Grassineau, N.; Nisbet, E.

    2003-04-01

    Methane emissions from landfills are an important source of European greenhouse emissions, and could be reduced by a biological management program that used methanotrophs in landfill cover soils. Topsoil samples taken from a London Landfill were incubated on Nitrate Mineral Salts medium in the presence of methane. The resulting colonies were probed for methanotrophic DNA using PCR amplification. DNA from methanotroph positive colonies was cloned and sequenced for identification. Isolates belonging to the genera Methylocaldum, Methylomonas and Methylosinus were detected. Phylogenetic analysis suggests the presence of possible new species. In addition dried samples of the isolates were analysed for their stable carbon isotope (δ 13C) composition. The results were δ 13C values of -27 per mil and -25 per mil for Methylomonas isolates, -35 per mil and -44 per mil for Methylosinus isolates, -58 per mil and -60 per mil for some of the Methylocaldum isolates and -35 per mil and -45 per mil for the others. This isotopic variation is reflected in a phylogenetic tree of the isolates. The differences shown in the δ 13C analysis could be due to differing biochemical properties, and if the technique is further developed, it may be used for rapid identification of bacteria useful in landfill management for reducing methane emissions. The results suggest that useful reductions in methane emissions could be achieved by a careful design of landfill cover to culture methanotrophs.

  10. On the relationship between methane production and oxidation by anaerobic methanotrophic communities from cold seeps of the Gulf of Mexico.

    PubMed

    Orcutt, Beth; Samarkin, Vladimir; Boetius, Antje; Joye, Samantha

    2008-05-01

    The anaerobic oxidation of methane (AOM) in the marine subsurface is a significant sink for methane in the environment, yet our understanding of its regulation and dynamics is still incomplete. Relatively few groups of microorganisms consume methane in subsurface environments--namely the anaerobic methanotrophic archaea (ANME clades 1, 2 and 3), which are phylogenetically related to methanogenic archaea. Anaerobic oxidation of methane presumably proceeds via a 'reversed' methanogenic pathway. The ANME are generally associated with sulfate-reducing bacteria (SRB) and sulfate is the only documented final electron acceptor for AOM in marine sediments. Our comparative study explored the coupling of AOM with sulfate reduction (SR) and methane generation (MOG) in microbial communities from Gulf of Mexico cold seep sediments that were naturally enriched with methane and other hydrocarbons. These sediments harbour a variety of ANME clades and SRB. Following enrichment under an atmosphere of methane, AOM fuelled 50-100% of SR, even in sediment slurries containing petroleum-associated hydrocarbons and organic matter. In the presence of methane and sulfate, the investigated microbial communities produce methane at a small fraction ( approximately 10%) of the AOM rate. Anaerobic oxidation of methane, MOG and SR rates decreased significantly with decreasing concentration of methane, and in the presence of the SR inhibitor molybdate, but reacted differently to the MOG inhibitor 2-bromoethanesulfonate (BES). The addition of acetate, a possible breakdown product of petroleum in situ and a potential intermediate in AOM/SR syntrophy, did not suppress AOM activity; rather acetate stimulated microbial activity in oily sediment slurries.

  11. Development of Aerobic Fitness in Young Team Sport Athletes.

    PubMed

    Harrison, Craig B; Gill, Nicholas D; Kinugasa, Taisuke; Kilding, Andrew E

    2015-07-01

    The importance of a high level of aerobic fitness for team sport players is well known. Previous research suggests that aerobic fitness can be effectively increased in adults using traditional aerobic conditioning methods, including high-intensity interval and moderate-intensity continuous training, or more recent game-based conditioning that involves movement and skill-specific tasks, e.g. small-sided games. However, aerobic fitness training for youth team sport players has received limited attention and is likely to differ from that for adults due to changes in maturation. Given young athletes experience different rates of maturation and technical skill development, the most appropriate aerobic fitness training modes and loading parameters are likely to be specific to the developmental stage of a player. Therefore, we analysed studies that investigated exercise protocols to enhance aerobic fitness in young athletes, relative to growth and maturation, to determine current best practice and limitations. Findings were subsequently used to guide an evidence-based model for aerobic fitness development. During the sampling stage (exploration of multiple sports), regular participation in moderate-intensity aerobic fitness training, integrated into sport-specific drills, activities and skill-based games, is recommended. During the specialisation stage (increased commitment to a chosen sport), high-intensity small-sided games should be prioritised to provide the simultaneous development of aerobic fitness and technical skills. Once players enter the investment stage (pursuit of proficiency in a chosen sport), a combination of small-sided games and high-intensity interval training is recommended.

  12. Unexpected DNA-fingerprinting pattern in a deep peat bog: evidence for methanotrophs at the bottom?

    NASA Astrophysics Data System (ADS)

    Steinmann, P.; Rossi, P.; Huon, S.; Eilrich, B.; Casati, S.

    2003-04-01

    With the goal of a better understanding of the fate of methane in the deep layers of peat bogs, we analysed the microbial 16S rDNA gene pool and measured the stable carbon isotope composition of bulk peat of a deep (6 m) peat bog profile (Etang de la Gruyère, Switzerland). Both Bacterial and Archaean communities were assessed using respectively TTGE (Temporal Temperature Gradient Electrophoresis) and SSCP (Single Strand Conformation Polymorphism), with fragments of the V1-V3 region of the 16S rDNA gene. The "relative diversity" shown in the TTGE AND SSCP gel patterns is presented using indices and band numbers per sample (Simpson evenness). PCA was calculated on the basis of the intensities of all bands found in the TTGE and SSCP fingerprinting profiles. These DNA fingerprinting patterns reveal the presence of a structured microbial community throughout the whole depth profile. Clear differences can be observed between the communities found in the near surface layers and those found at depth. Surprisingly, for both Archaean and Bacterial communities, the deepest samples display a high similarity level with those found in the first 20 centimeters. The δ13C values of the peat are relatively constant from the surface of the bog down to a depth of 5 m (values between 25.5 ppm and 26.5 ppm). Below 5 m the values decrease considerably with depth ( 28.5 ppm). As a working hypothesis to explain the two observations, we consider the possibility of the presence of methanotrophs in the deepest parts of the bogs. The electron acceptors needed for methane oxidation could be derived from lateral advection of less reducing groundwater. However, available pore water analyses suggest that neither molecular oxygen, nor sulfate or nitrate are present. One possible oxidising agent would be trivalent iron (solid or colloidal). Indeed are the iron concentrations in the deeper pore waters are elevated. Such deep methanotrophic microbial community could be similar to those found near

  13. Physiological and functional diversity of phenol degraders isolated from phenol-grown aerobic granules: Phenol degradation kinetics and trichloroethylene co-metabolic activities.

    PubMed

    Zhang, Yi; Tay, Joo Hwa

    2016-03-15

    Aerobic granule is a novel form of microbial aggregate capable of degrading toxic and recalcitrant substances. Aerobic granules have been formed on phenol as the growth substrate, and used to co-metabolically degrade trichloroethylene (TCE), a synthetic solvent not supporting aerobic microbial growth. Granule formation process, rate limiting factors and the comprehensive toxic effects of phenol and TCE had been systematically studied. To further explore their potential at the level of microbial population and functions, phenol degraders were isolated and purified from mature granules in this study. Phenol and TCE degradation kinetics of 15 strains were determined, together with their TCE transformation capacities and other physiological characteristics. Isolation in the presence of phenol and TCE exerted stress on microbial populations, but the procedure was able to preserve their diversity. Wide variation was found with the isolates' kinetic behaviors, with the parameters often spanning 3 orders of magnitude. Haldane kinetics described phenol degradation well, and the isolates exhibited actual maximum phenol-dependent oxygen utilization rates of 9-449 mg DO g DW(-1) h(-1), in phenol concentration range of 4.8-406 mg L(-1). Both Michaelis-Menten and Haldane types were observed for TCE transformation, with the actual maximum rate of 1.04-21.1 mg TCE g DW(-1) h(-1) occurring between TCE concentrations of 0.42-4.90 mg L(-1). The TCE transformation capacities and growth yields on phenol ranged from 20-115 mg TCE g DW(-1) and 0.46-1.22 g DW g phenol(-1), respectively, resulting in TCE transformation yields of 10-70 mg TCE g phenol(-1). Contact angles of the isolates were between 34° and 82°, suggesting both hydrophobic and hydrophilic cell surface. The diversity in the isolates is a great advantage, as it enables granules to be versatile and adaptive under different operational conditions.

  14. Successful treatment of high azo dye concentration wastewater using combined anaerobic/aerobic granular activated carbon-sequencing batch biofilm reactor (GAC-SBBR): simultaneous adsorption and biodegradation processes.

    PubMed

    Hosseini Koupaie, E; Alavi Moghaddam, M R; Hashemi, S H

    2013-01-01

    The application of a granular activated carbon-sequencing batch biofilm reactor (GAC-SBBR) for treatment of wastewater containing 1,000 mg/L Acid Red 18 (AR18) was investigated in this research. The treatment system consisted of a sequencing batch reactor equipped with moving GAC as biofilm support. Each treatment cycle consisted of two successive anaerobic (14 h) and aerobic (8 h) reaction phases. Removal of more than 91% chemical oxygen demand (COD) and 97% AR18 was achieved in this study. Investigation of dye decolorization kinetics showed that the dye removal was stimulated by the adsorption capacity of the GAC at the beginning of the anaerobic phase and then progressed following a first-order reaction. Based on COD analysis results, at least 77.8% of the dye total metabolites were mineralized during the applied treatment system. High-performance liquid chromatography analysis revealed that more than 97% of 1-naphthyalamine-4-sulfonate as one of the main sulfonated aromatic constituents of AR18 was removed during the aerobic reaction phase. According to the scanning electron microscopic analysis, the microbial biofilms grew in most cavities and pores of the GAC, but not on the external surfaces of the GAC.

  15. The metatranscriptome of a deep-sea hydrothermal plume is dominated by water column methanotrophs and lithotrophs

    PubMed Central

    Lesniewski, Ryan A; Jain, Sunit; Anantharaman, Karthik; Schloss, Patrick D; Dick, Gregory J

    2012-01-01

    Microorganisms mediate geochemical processes in deep-sea hydrothermal vent plumes, which are a conduit for transfer of elements and energy from the subsurface to the oceans. Despite this important microbial influence on marine geochemistry, the ecology and activity of microbial communities in hydrothermal plumes is largely unexplored. Here, we use a coordinated metagenomic and metatranscriptomic approach to compare microbial communities in Guaymas Basin hydrothermal plumes to background waters above the plume and in the adjacent Carmen Basin. Despite marked increases in plume total RNA concentrations (3–4 times) and microbially mediated manganese oxidation rates (15–125 times), plume and background metatranscriptomes were dominated by the same groups of methanotrophs and chemolithoautotrophs. Abundant community members of Guaymas Basin seafloor environments (hydrothermal sediments and chimneys) were not prevalent in the plume metatranscriptome. De novo metagenomic assembly was used to reconstruct genomes of abundant populations, including Marine Group I archaea, Methylococcaceae, SAR324 Deltaproteobacteria and SUP05 Gammaproteobacteria. Mapping transcripts to these genomes revealed abundant expression of genes involved in the chemolithotrophic oxidation of ammonia (amo), methane (pmo) and sulfur (sox). Whereas amo and pmo gene transcripts were abundant in both plume and background, transcripts of sox genes for sulfur oxidation from SUP05 groups displayed a 10–20-fold increase in plumes. We conclude that the biogeochemistry of Guaymas Basin hydrothermal plumes is mediated by microorganisms that are derived from seawater rather than from seafloor hydrothermal environments such as chimneys or sediments, and that hydrothermal inputs serve as important electron donors for primary production in the deep Gulf of California. PMID:22695860

  16. A Highly Active System for the Metal-Free Aerobic Photocyanation of Tertiary Amines with Visible Light: Application to the Synthesis of Tetraponerines and Crispine A.

    PubMed

    Orejarena Pacheco, Julio Cesar; Lipp, Alexander; Nauth, Alexander M; Acke, Fabian; Dietz, Jule-Philipp; Opatz, Till

    2016-04-04

    A highly efficient metal-free catalytic system for the aerobic photocyanation of tertiary amines with visible light is reported. The use of air as terminal oxidant offers an improved safety profile compared with pure oxygen, the used compact fluorescent lamp (CFL) light sources are highly economical, and no halogenated solvents are required. This system not only proves to be effective for a wide variety of trialkylamines, pharmaceuticals, and alkaloids but remarkably also allows the lowest catalyst loading (0.00001 mol% or 0.1 ppm) ever reported for an organic dye. Bruylants reactions and C-alkylation/decyanations were performed on the obtained α-aminonitriles to demonstrate the postfunctionalization of complex molecules. The catalytic system is furthermore applied in the short and effective syntheses of the alkaloids (±)-crispine A and the tetraponerines T7 and T8.

  17. Project Summary. IN-SITU AQUIFER RESTORATION OF CHLORINATED ALIPHATICS BY METHANOTROPHIC BACTERIA

    EPA Science Inventory

    This project evaluated the potential of an innovative approach to aquifer restoration: enhanced in-situ biotransformation of chlorinated aliphatic solvents by a bacterial community grown on methane under aerobic conditions. The target chlorinated compounds were trichloroethene (...

  18. Toxic and inhibitory effects of trichloroethylene aerobic co-metabolism on phenol-grown aerobic granules.

    PubMed

    Zhang, Yi; Tay, JooHwa

    2015-04-09

    Aerobic granule, a form of microbial aggregate, exhibits good potential in degrading toxic and recalcitrant substances. In this study, the inhibitory and toxic effects of trichloroethylene (TCE), a model compound for aerobic co-metabolism, on phenol-grown aerobic granules were systematically studied, using respiratory activities after exposure to TCE as indicators. High TCE concentration did not exert positive or negative effects on the subsequent endogenous respiration rate or phenol dependent specific oxygen utilization rate (SOUR), indicating the absence of solvent stress and induction effect on phenol-hydroxylase. Phenol-grown aerobic granules exhibited a unique response to TCE transformation product toxicity, that small amount of TCE transformation enhanced the subsequent phenol SOUR. Granules that had transformed between 1.3 and 3.7 mg TCE gSS(-1) showed at most 53% increase in the subsequent phenol SOUR, and only when the transformation exceeded 6.6 mg TCE gSS(-1) did the SOUR dropped below that of the control. This enhancing effect was found to sustain throughout several phenol dosages, and TCE transformation below the toxicity threshold also lessened the granules' sensitivity to higher phenol concentration. The unique toxic effect was possibly caused by the granule's compact structure as a protection barrier against the diffusive transformation product(s) of TCE co-metabolism.

  19. Use of Temperature and Surface Gas Flux as Novel Measures of Microbial Activity at a Crude Oil Spill Site

    NASA Astrophysics Data System (ADS)

    Bekins, B. A.; Warren, E.; Sihota, N. J.; Hostettler, F. D.

    2012-12-01

    Degradation of crude oil in the subsurface has been studied for over 30 years at a spill site located near Bemidji, Minnesota, USA. The well-characterized site is being used to experiment with the use of surface gas flux and temperature measurements as novel methods for quantifying microbial activity. In the largest subsurface oil body, a 2-m-thick smear zone spans the water table 6-8 m below the surface. Methane produced from degradation of the oil diffuses upward and mixes with oxygen from the surface supporting aerobic methanotrophy at 2-4 m depth. The methane oxidation produces CO2 and heat at rates which are hypothetically proportional to other measures of subsurface microbial activity. To test this hypothesis, vertical profiles of temperature and microbial populations, surface CO2 flux, and oil degradation state were measured at three sites in the oil body and one background site. Temperature increases in the oil zone near the water table were 1-4°C above the background site. The site with the highest temperature increase at the water table also had the highest concentrations of gene copy numbers for methanogens (mcrA) and methanotrophs (pmoA) along with the most degraded oil. Surface CO2 flux over the oil sites averaged more than twice that at the background site but was not consistently highest over the site with the highest activity by other measures. One possible explanation for this discrepancy is variation in the effective diffusion coefficient of the vadose zone between the methanotrophic zone and the surface. At the level of the methanotrophic zone, temperatures were elevated 2-6°C over the background values but again the site with greatest average annual temperature increase was not at the most active site. This may be due to enhanced recharge at the most active site, which lies at the center of a local topographic depression where focused recharge occurs. Overall, the temperature and flux data showed significant increases at the oil sites compared

  20. Responses of soil methanogens, methanotrophs, and methane fluxes to land-use conversion and fertilization in a hilly red soil region of southern China.

    PubMed

    Liu, Huifeng; Wu, Xing; Li, Zongshan; Wang, Qing; Liu, Dan; Liu, Guohua

    2017-03-01

    Changes in land-uses and fertilization are important factors regulating methane (CH4) emissions from paddy soils. However, the responses of soil CH4 emissions to these factors and the underlying mechanisms remain unclear. The objective of this study was to explore the effects of land-use conversion from paddies to orchards and fertilization on soil CH4 fluxes, and the abundance and community compositions of methanogens and methanotrophs. Soil CH4 fluxes were quantified by static chamber and gas chromatography technology. Abundance and community structures of methanogens and methanotrophs (based on mcrA and pmoA genes, respectively) were determined by quantitative real-time PCR (qPCR), and terminal restriction fragment length polymorphism (TRFLP), cloning and sequence analysis, respectively. Results showed that land-use conversion from paddies to orchards dramatically decreased soil CH4 fluxes, whereas fertilization did not distinctly affect soil CH4 fluxes. Furthermore, abundance of methanogens and methanotrophs were decreased after converting paddies to orchards. Fertilization decreased the abundance of these microorganisms, but the values were not statistically significant. Moreover, land-use conversion had fatal effects on some members of the methanogenic archaea (Methanoregula and Methanosaeta), increased type II methanotrophs (Methylocystis and Methylosinus), and decreased type I methanotrophs (Methylobacter and Methylococcus). However, fertilization could only significantly affect type I methanotrophs in the orchard plots. In addition, CH4 fluxes from paddy soils were positively correlated with soil dissolved organic carbon contents and methanogens abundance, whereas CH4 fluxes in orchard plots were negatively related to methanotroph abundance. Therefore, our results suggested that land-use conversion from paddies to orchards could change the abundance and community compositions of methanogens and methanotrophs, and ultimately alter the soil CH4 fluxes

  1. Dissimilatory perchlorate reduction linked to aerobic methane oxidation via chlorite dismutase

    NASA Astrophysics Data System (ADS)

    Oremland, R. S.; Baesman, S. M.; Miller, L. G.

    2013-12-01

    The presence of methane (CH4) in the atmosphere of Mars is controversial yet the evidence has aroused scientific interest, as CH4 could be a harbinger of extant or extinct microbial life. There are various oxidized compounds present on the surface of Mars that could serve as electron acceptors for the anaerobic oxidation of CH4, including perchlorate (ClO4-). We examined the role of perchlorate, chlorate (ClO3-) and chlorite (ClO2-) as oxidants linked to CH4 oxidation. Dissimilatory perchlorate reduction begins with reduction of ClO4- to ClO2- and ends with dismutation of chlorite to yield chloride (Cl-) and molecular oxygen (O2). We explored the potential for aerobic CH4 oxidizing bacteria to couple with oxygen derived from chlorite dismutation during dissimilatory perchlorate reduction. Methane (0.2 kPa) was completely removed within several days from the N2-flushed headspace above cell suspensions of methanotrophs (Methylobacter albus strain BG8) and perchlorate reducing bacteria (Dechloromonas agitata strain CKB) in the presence of 5 mM ClO2-. Similar rates of CH4 consumption were observed for these mixed cultures whether they were co-mingled or segregated under a common headspace, indicating that direct contact of cells was not required for methane consumption to occur. We also observed complete removal of 0.2 kPa CH4 in bottles containing dried soil (enriched in methanotrophs by CH4 additions over several weeks) and D. agitata CKB and in the presence of 10 mM ClO2-. This soil (seasonally exposed sediment) collected from the shoreline of a freshwater lake (Searsville Lake, CA) demonstrated endogenous CH4 uptake as well as perchlorate, chlorate and chlorite reduction/dismutation. However, these experiments required physical separation of soil from the aqueous bacterial culture to allow for the partitioning of O2 liberated from chlorite dismutation into the shared headspace. Although dissimilatory reduction of ClO4- and ClO3- could be inferred from the

  2. Relating subsurface temperature changes to microbial activity at a crude oil-contaminated site

    NASA Astrophysics Data System (ADS)

    Warren, Ean; Bekins, Barbara A.

    2015-11-01

    Crude oil at a spill site near Bemidji, Minnesota has been undergoing aerobic and anaerobic biodegradation for over 30 years, creating a 150-200 m plume of primary and secondary contaminants. Microbial degradation generates heat that should be measurable under the right conditions. To measure this heat, thermistors were installed in wells in the saturated zone and in water-filled monitoring tubes in the unsaturated zone. In the saturated zone, a thermal groundwater plume originates near the residual oil body with temperatures ranging from 2.9 °C above background near the oil to 1.2 °C down gradient. Temperatures in the unsaturated zone above the oil body were up to 2.7 °C more than background temperatures. Previous work at this site has shown that methane produced from biodegradation of the oil migrates upward and is oxidized in a methanotrophic zone midway between the water table and the surface. Enthalpy calculations and observations demonstrate that the temperature increases primarily result from aerobic methane oxidation in the unsaturated zone above the oil. Methane oxidation rates at the site independently estimated from surface CO2 efflux data are comparable to rates estimated from the observed temperature increases. The results indicate that temperature may be useful as a low-cost measure of activity but care is required to account for the correct heat-generating reactions, other heat sources and the effects of focused recharge.

  3. Relating subsurface temperature changes to microbial activity at a crude oil-contaminated site.

    PubMed

    Warren, Ean; Bekins, Barbara A

    2015-11-01

    Crude oil at a spill site near Bemidji, Minnesota has been undergoing aerobic and anaerobic biodegradation for over 30 years, creating a 150-200 m plume of primary and secondary contaminants. Microbial degradation generates heat that should be measurable under the right conditions. To measure this heat, thermistors were installed in wells in the saturated zone and in water-filled monitoring tubes in the unsaturated zone. In the saturated zone, a thermal groundwater plume originates near the residual oil body with temperatures ranging from 2.9°C above background near the oil to 1.2°C down gradient. Temperatures in the unsaturated zone above the oil body were up to 2.7°C more than background temperatures. Previous work at this site has shown that methane produced from biodegradation of the oil migrates upward and is oxidized in a methanotrophic zone midway between the water table and the surface. Enthalpy calculations and observations demonstrate that the temperature increases primarily result from aerobic methane oxidation in the unsaturated zone above the oil. Methane oxidation rates at the site independently estimated from surface CO2 efflux data are comparable to rates estimated from the observed temperature increases. The results indicate that temperature may be useful as a low-cost measure of activity but care is required to account for the correct heat-generating reactions, other heat sources and the effects of focused recharge.

  4. Relating subsurface temperature changes to microbial activity at a crude oil-contaminated site

    USGS Publications Warehouse

    Warren, Ean; Bekins, Barbara A.

    2015-01-01

    Crude oil at a spill site near Bemidji, Minnesota has been undergoing aerobic and anaerobic biodegradation for over 30 years, creating a 150–200 m plume of primary and secondary contaminants. Microbial degradation generates heat that should be measurable under the right conditions. To measure this heat, thermistors were installed in wells in the saturated zone and in water-filled monitoring tubes in the unsaturated zone. In the saturated zone, a thermal groundwater plume originates near the residual oil body with temperatures ranging from 2.9 °C above background near the oil to 1.2 °C down gradient. Temperatures in the unsaturated zone above the oil body were up to 2.7 °C more than background temperatures. Previous work at this site has shown that methane produced from biodegradation of the oil migrates upward and is oxidized in a methanotrophic zone midway between the water table and the surface. Enthalpy calculations and observations demonstrate that the temperature increases primarily result from aerobic methane oxidation in the unsaturated zone above the oil. Methane oxidation rates at the site independently estimated from surface CO2 efflux data are comparable to rates estimated from the observed temperature increases. The results indicate that temperature may be useful as a low-cost measure of activity but care is required to account for the correct heat-generating reactions, other heat sources and the effects of focused recharge.

  5. We Huff and Puff: The Parameters and the Program of Aerobics for Children under Five.

    ERIC Educational Resources Information Center

    Eastman, Wayne

    In today's society, young children have few experiences with aerobic activities, a pattern of exercise traditionally reserved for adults. This paper discusses how aerobic exercises can be used in a preschool environment, arguing that such activities are best presented using a thematic approach so that young children can form impressions about…

  6. Structure and function of methanotrophic communities in a landfill-cover soil.

    PubMed

    Henneberger, Ruth; Lüke, Claudia; Mosberger, Lona; Schroth, Martin H

    2012-07-01

    In landfill-cover soils, aerobic methane-oxidizing bacteria (MOB) convert CH(4) to CO(2), mitigating emissions of the greenhouse gas CH(4) to the atmosphere. We investigated overall MOB community structure and assessed spatial differences in MOB diversity, abundance and activity in a Swiss landfill-cover soil. Molecular cloning, terminal restriction-fragment length polymorphism (T-RFLP) and quantitative PCR of pmoA genes were applied to soil collected from 16 locations at three different depths to study MOB community structure, diversity and abundance; MOB activity was measured in the field using gas push-pull tests. The MOB community was highly diverse but dominated by Type Ia MOB, with novel pmoA sequences present. Type II MOB were detected mainly in deeper soil with lower nutrient and higher CH(4) concentrations. Substantial differences in MOB community structure were observed between one high- and one low-activity location. MOB abundance was highly variable across the site [4.0 × 10(4) to 1.1 × 10(7) (g soil dry weight)(-1)]. Potential CH(4) oxidation rates were high [1.8-58.2 mmol CH(4) (L soil air)(-1) day(-1) ] but showed significant lateral variation and were positively correlated with mean CH(4) concentrations (P < 0.01), MOB abundance (P < 0.05) and MOB diversity (weak correlation, P < 0.17). Our findings indicate that Methylosarcina and closely related MOB are key players and that MOB abundance and community structure are driving factors in CH(4) oxidation at this landfill.

  7. Microbial Removal of Atmospheric Carbon Tetrachloride in Bulk Aerobic Soils▿

    PubMed Central

    Mendoza, Y.; Goodwin, K. D.; Happell, J. D.

    2011-01-01

    Atmospheric concentrations of carbon tetrachloride (CCl4) were removed by bulk aerobic soils from tropical, subtropical, and boreal environments. Removal was observed in all tested soil types, indicating that the process was widespread. The flux measured in field chamber experiments was 0.24 ± 0.10 nmol CCl4 (m2 day)−1 (average ± standard deviation [SD]; n = 282). Removal of CCl4 and removal of methane (CH4) were compared to explore whether the two processes were linked. Removal of both gases was halted in laboratory samples that were autoclaved, dry heated, or incubated in the presence of mercuric chloride (HgCl2). In marl soils, treatment with antibiotics such as tetracycline and streptomycin caused partial inhibition of CCl4 (50%) and CH4 (76%) removal, but removal was not affected in soils treated with nystatin or myxothiazol. These data indicated that bacteria contributed to the soil removal of CCl4 and that microeukaryotes may not have played a significant role. Amendments of methanol, acetate, and succinate to soil samples enhanced CCl4 removal by 59%, 293%, and 72%, respectively. Additions of a variety of inhibitors and substrates indicated that nitrification, methanogenesis, or biological reduction of nitrate, nitrous oxide, or sulfate (e.g., occurring in possible anoxic microzones) did not play a significant role in the removal of CCl4. Methyl fluoride inhibited removal of CH4 but not CCl4, indicating that CH4 and CCl4 removals were not directly linked. Furthermore, CCl4 removal was not affected in soils amended with copper sulfate or methane, supporting the results with MeF and suggesting that the observed CCl4 removal was not significantly mediated by methanotrophs. PMID:21724884

  8. Aerobic Capacity and Postprandial Flow Mediated Dilation.

    PubMed

    Ballard, Kevin D; Miller, James J; Robinson, James H; Olive, Jennifer L

    The consumption of a high-fat meal induces transient vascular dysfunction. Aerobic exercise enhances vascular function in healthy individuals. Our purpose was to determine if different levels of aerobic capacity impact vascular function, as measured by flow mediated dilation, following a high-fat meal. Flow mediated dilation of the brachial artery was determined before, two- and four-hours postprandial a high-fat meal in young males classified as highly trained (n = 10; VO2max = 74.6 ± 5.2 ml·kg·min(-1)) or moderately active (n = 10; VO2max = 47.3 ± 7.1 ml·kg·min(-1)). Flow mediated dilation was reduced at two- (p < 0.001) and four-hours (p < 0.001) compared to baseline for both groups but was not different between groups at any time point (p = 0.108). Triglycerides and insulin increased at two- (p < 0.001) and four-hours (p < 0.05) in both groups. LDL-C was reduced at four-hours (p = 0.05) in highly trained subjects, and two- and four-hours (p ≤ 0.01) in moderately active subjects. HDL-C decreased at two- (p = 0.024) and four-hours (p = 0.014) in both groups. Glucose increased at two-hours postprandial for both groups (p = 0.003). Our results indicate that a high-fat meal results in reduced endothelium-dependent vasodilation in highly trained and moderately active individuals with no difference between groups. Thus, high aerobic capacity does not protect against transient reductions in vascular function after the ingestion of a single high-fat meal compared to individuals who are moderately active.

  9. Responses of Methanogenic and Methanotrophic Communities to Elevated Atmospheric CO2 and Temperature in a Paddy Field.

    PubMed

    Liu, Yuan; Liu, Xiaoyu; Cheng, Kun; Li, Lianqing; Zhang, Xuhui; Zheng, Jufeng; Zheng, Jinwei; Pan, Genxing

    2016-01-01

    Although climate change is predicted to affect methane (CH4) emissions in paddy soil, the dynamics of methanogens and methanotrophs in paddy fields under climate change have not yet been fully investigated. To address this issue, a multifactor climate change experiment was conducted in a Chinese paddy field using the following experimental treatments: (1) enrichment of atmospheric CO2 concentrations (500 ppm, CE), (2) canopy air warming (2°C above the ambient, WA), (3) combined CO2 enrichment and warming (CW), and (4) ambient conditions (CK). We analyzed the abundance of methanogens and methanotrophs, community structures, CH4 production and oxidation potentials, in situ CH4 emissions using real-time PCR, T-RFLP, and clone library techniques, as well as biochemical assays. Compared to the control under CE and CW treatments, CH4 production potential, methanogenic gene abundance and soil microbial biomass carbon significantly increased; the methanogenic community, however, remained stable. The canopy air warming treatment only had an effect on CH4 oxidation potential at the ripening stage. Phylogenic analysis indicated that methanogens in the rhizosphere were dominated by Methanosarcina, Methanocellales, Methanobacteriales, and Methanomicrobiales, while methanotrophic sequences were classified as Methylococcus, Methylocaldum, Methylomonas, Methylosarcina (Type I) and Methylocystis (Type II). However, the relative abundance of Methylococcus (Type I) decreased under CE and CW treatments and the relative abundance of Methylocystis (Type II) increased. The in situ CH4 fluxes indicated similar seasonal patterns between treatments; both CE and CW increased CH4 emissions. In conclusion results suggest that methanogens and methanotrophs respond differently to elevated atmospheric CO2 concentrations and warming, thus adding insights into the effects of simulated global climate change on CH4 emissions in paddy fields.

  10. Responses of Methanogenic and Methanotrophic Communities to Elevated Atmospheric CO2 and Temperature in a Paddy Field

    PubMed Central

    Liu, Yuan; Liu, Xiaoyu; Cheng, Kun; Li, Lianqing; Zhang, Xuhui; Zheng, Jufeng; Zheng, Jinwei; Pan, Genxing

    2016-01-01

    Although climate change is predicted to affect methane (CH4) emissions in paddy soil, the dynamics of methanogens and methanotrophs in paddy fields under climate change have not yet been fully investigated. To address this issue, a multifactor climate change experiment was conducted in a Chinese paddy field using the following experimental treatments: (1) enrichment of atmospheric CO2 concentrations (500 ppm, CE), (2) canopy air warming (2°C above the ambient, WA), (3) combined CO2 enrichment and warming (CW), and (4) ambient conditions (CK). We analyzed the abundance of methanogens and methanotrophs, community structures, CH4 production and oxidation potentials, in situ CH4 emissions using real-time PCR, T-RFLP, and clone library techniques, as well as biochemical assays. Compared to the control under CE and CW treatments, CH4 production potential, methanogenic gene abundance and soil microbial biomass carbon significantly increased; the methanogenic community, however, remained stable. The canopy air warming treatment only had an effect on CH4 oxidation potential at the ripening stage. Phylogenic analysis indicated that methanogens in the rhizosphere were dominated by Methanosarcina, Methanocellales, Methanobacteriales, and Methanomicrobiales, while methanotrophic sequences were classified as Methylococcus, Methylocaldum, Methylomonas, Methylosarcina (Type I) and Methylocystis (Type II). However, the relative abundance of Methylococcus (Type I) decreased under CE and CW treatments and the relative abundance of Methylocystis (Type II) increased. The in situ CH4 fluxes indicated similar seasonal patterns between treatments; both CE and CW increased CH4 emissions. In conclusion results suggest that methanogens and methanotrophs respond differently to elevated atmospheric CO2 concentrations and warming, thus adding insights into the effects of simulated global climate change on CH4 emissions in paddy fields. PMID:27933055

  11. Mood alterations in mindful versus aerobic exercise modes.

    PubMed

    Netz, Yael; Lidor, Ronnie

    2003-09-01

    The results of most recent studies have generally indicated an improvement in mood after participation in aerobic exercise. However, only a few researchers have compared mindful modes of exercise with aerobic exercise to examine the effect of 1 single session of exercise on mood. In the present study, the authors assessed state anxiety, depressive mood, and subjective well-being prior to and following 1 class of 1 of 4 exercise modes: yoga, Feldenkrais (awareness through movement), aerobic dance, and swimming; a computer class served as a control. Participants were 147 female general curriculum and physical education teachers (mean age = 40.15, SD = 0.2) voluntarily enrolled in a 1-year enrichment program at a physical education college. Analyses of variance for repeated measures revealed mood improvement following Feldenkrais, swimming, and yoga but not following aerobic dance and computer lessons. Mindful low-exertion activities as well as aerobic activities enhanced mood in 1 single session of exercise. The authors suggest that more studies assessing the mood-enhancing benefits of mindful activities such as Feldenkrais and yoga are needed.

  12. Copper-Catalyzed Aerobic Oxidations of Organic Molecules: Pathways for Two-Electron Oxidation with a Four-Electron Oxidant and a One-Electron Redox-Active Catalyst.

    PubMed

    McCann, Scott D; Stahl, Shannon S

    2015-06-16

    Selective oxidation reactions have extraordinary value in organic chemistry, ranging from the conversion of petrochemical feedstocks into industrial chemicals and polymer precursors to the introduction of heteroatom functional groups into pharmaceutical and agrochemical intermediates. Molecular oxygen (O2) would be the ideal oxidant for these transformations. Whereas many commodity-scale oxidations of simple hydrocarbon feedstocks employ O2 as an oxidant, methods for selective oxidation of more complex molecules bearing diverse functional groups are often incompatible with existing aerobic oxidation methods. The latter limitation provides the basis for our interest in the development of new catalytic transformations and the elucidation of mechanistic principles that underlie selective aerobic oxidation reactions. One challenge inherent in such methods is the incommensurate redox stoichiometry associated with the use of O2, a four-electron oxidant, in reactions that achieve two-electron oxidation of organic molecules. This issue is further complicated by the use of first-row transition-metal catalysts, which tend to undergo facile one-electron redox steps. In recent years, we have been investigating Cu-catalyzed aerobic oxidation reactions wherein the complexities just noted are clearly evident. This Account surveys our work in this area, which has emphasized three general classes of reactions: (1) single-electron-transfer reactions for oxidative functionalization of electron-rich substrates, such as arenes and heterocycles; (2) oxidative carbon-heteroatom bond-forming reactions, including C-H oxidations, that proceed via organocopper(III) intermediates; and (3) methods for aerobic oxidation of alcohols and amines that use Cu(II) in combination with an organic redox-active cocatalyst to dehydrogenate the carbon-heteroatom bond. These reaction classes demonstrate three different pathways to achieve two-electron oxidation of organic molecules via the cooperative

  13. Use of gene probes to assess the impact and effectiveness of aerobic In situ bioremediation of TCE.

    SciTech Connect

    Hazen, Terry C.; Chakraborty, Romy; Fleming, James M.; Gregory, Ingrid R.; Bowman, John P.; Jimenez, Luis; Zhang, Dai; Pfiffner, Susan M.; Brockman, Fred J.; Sayler, Gary S.

    2009-03-01

    Gene probe hybridization was used to determine distribution and expression of co-metabolic genes at a contaminated site as it underwent in situ methanotrophic bioremediation of trichloroethylene (TCE). The bioremediation strategies tested consisted of a series of air, air:methane, and air:methane:nutrient pulses using a horizontal injection well. Sediment core samples (n=367) taken from 0 (surface)-43m depth were probed for genes coding for soluble methane monooxygenase (sMMO) and toluene dioxygenase (TOD), which are known to cometabolize TCE. The same samples were also probed for genes coding for methanol dehydrogenase (MDH) to access changes in methylotrophic bacterial populations. Hybridization results showed that the frequency of detection of sMMO genes were stimulated approximately 250% following 1% methane:air (v/v) injection. Subsequent 4% methane:air (v/v) injection resulted in an 85% decline probably due to nutrient limitations, since subsequent addition of nutrients (gaseous nitrogen and phosphorus) caused an increase in the frequency of detection of sMMO genes. Detection of TOD genes declined during the process becoming non-detectable by the final treatment. These patterns indicate methanotrophs displaced heterotrophs containing TOD genes. Active transcription of sMMO and TOD was evidenced by hybridization to mRNA. These analyses combined with studies showing the concomitant decline in TCE concentrations, increases in methanotroph viable counts, increased mineralization rates of TCE, and increases in chloride inventories provide multiple lines of evidence that TCE remediation was caused specifically by methanotrophs. This work suggests that sMMO genes are responsible for most, if not all, of the biodegradation of TCE observed. This study demonstrated that the use of nucleic acid analytical methods provided a gene specific assessment of the effects of in situ treatment technologies.

  14. Methanotrophic bacteria associated to rice roots: the cultivar effect assessed by T-RFLP and microarray analysis.

    PubMed

    Lüke, Claudia; Bodrossy, Levente; Lupotto, Elisabetta; Frenzel, Peter

    2011-10-01

    Rice plants play a key role in regulating methane emissions from paddy fields by affecting both underlying processes: methane production and oxidation. Specific differences were reported for methane oxidation rates; however, studies on the bacterial communities involved are rare. Here, we analysed the methanotrophic community on the roots of 18 different rice cultivars by pmoA-based terminal restriction fragment length polymorphism (T-RFLP) and microarray analysis. Both techniques showed comparable and consistent results revealing a high diversity dominated by type II and type Ib methanotrophs. pmoA microarrays have been successfully used to study methane-oxidizing bacteria in various environments. However, the microarray's full potential resolving community structure has not been exploited yet. Here, we provide an example on how to include this information into multivariate statistics. The analysis revealed a rice cultivar effect on the methanotroph community composition that could be affiliated to the plant genotype. This effect became only significant by including the specific phylogenetic resolution provided by the microarray into the statistical analysis.

  15. Stable carbon isotope fractionation of trans-1,2-dichloroethylene during co-metabolic degradation by methanotrophic bacteria

    USGS Publications Warehouse

    Brungard, Karen L.; Munakata-Marr, Junko; Johnson, Craig A.; Mandernack, Kevin W.

    2003-01-01

    Changes in the carbon isotope ratio (δ13C) of trans-1,2-dichloroethylene (t-DCE) were measured during its co-metabolic degradation by Methylomonas methanica, a type I methanotroph, and Methylosinus trichosporium OB3b, a type II methanotroph. In closed-vessel incubation experiments with each bacterium, the residual t-DCE became progressively enriched in 13C, indicating isotopic fractionation. From these experiments, the biological fractionation during t-DCE co-metabolism, expressed as ε, was measured to be -3.50/00 for the type I culture and -6.70/00 for the type II culture. This fractionation effect and subsequent enrichment in the δ13C of the residual t-DCE can thus be applied to determine the extent of biodegradation of DCE by these organisms. Based on these results, isotopic fractionation clearly warrants further study, as measured changes in the δ13C values of chlorinated solvents could ultimately be used to monitor the extent of biodegradation in laboratory or field settings where co-metabolism by methanotrophs occurs.

  16. Methylomonas scandinavica sp. nov., a new methanotrophic psychrotrophic bacterium isolated from deep igneous rock ground water of Sweden.

    PubMed

    Kalyuzhnaya, M G; Khmelenina, V N; Kotelnikova, S; Holmquist, L; Pedersen, K; Trotsenko, Y A

    1999-12-01

    Methane-utilizing bacteria were enriched from deep igneous rock environments and affiliated by amplification of functional and phylogenetic gene probes. Type I methanotrophs belonging to the genera Methylomonas and Methylobacter dominated in enrichment cultures from depths below 400 m. A pure culture of an obligate methanotroph (strain SR5) was isolated and characterized. Pink-pigmented motile rods of the new isolate contained intracytoplasmic membranes as stacks of vesicles, assimilated methane via the ribulose monophosphate pathway and had an incomplete tricarboxylic acid cycle. Phosphatidyl glycerol, methylene ubiquinone and cytochrome c552 were prevailing. The DNA G+C content is 53.3 mol %. Strain SR5 grew at temperatures between 5 and 30 degrees C with optimum at 15 degrees C, close to its in situ temperature. Analyses of 16S rRNA gene, whole cell protein, enzymatic and physiological analyses of strain SR-5 revealed significant differences compared to the other representatives of Type I methanotrophs. Based on pheno- and genotypic characteristics we propose to refer the strain SR5 as to a new species, Methylomonas scandinavica.

  17. Methanotrophs, Methylosinus trichosporium OB3b, sMMO, and their application to bioremediation.

    PubMed

    Sullivan, J P; Dickinson, D; Chase, H A

    1998-01-01

    One of the most problematic groups of the USEPA and EU priority pollutants are the halogenated organic compounds. These substances have a wide range of industrial applications, such as solvents and cleaners. Inadequate disposal techniques and accidental spillages have led to their detection in soil, groundwater, and river sediments. Persistence of these compounds in the environment has resulted from low levels of biodegradation due to chemical structural features that preclude or retard biological attack. Research has indicated the idea that treatment systems based on methanotrophic co-metabolic transformation may be a cost-effective and efficient alternative to physical methods because of the potential for high transformation rates, the possibility of complete compound degradation without the formation of toxic metabolites, applicability to a broad spectrum of compounds, and the use of a widely available and inexpensive growth substrate. A substantial amount of work concerning methanotrophic cometabolic transformations has been carried out using the soluble form of methane monooxygenase (sMMO) from the obligate methanotroph Methylosinus trichosporium OB3b. This NADH-dependent monooxygenase is derepressed when cells are grown under copper stress. sMMO has a wider specificity than the particulate form. sMMO has been shown to degrade trichloroethylene (TCE) at a rate of at least one order of magnitude faster than obtained with other mixed and pure cultures, suggesting it has a wider application to bioremediation. Furthermore, sMMO catalyzes an unusually wide range of oxidation reactions, including the hydroxylation of alkanes, epoxidation of alkenes, ethers, halogenated methanes, cyclic and aromatic compounds including compounds, that are resistant to degradation in the environment. However, the practical application of methantrophs and Methylosinus trichosporium OB3b to the treatment of chlorinated organics has met with mixed success. Although oxidation rates are

  18. Relative importance of aerobic versus resistance training for healthy aging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This review will focus on the importance of aerobic and resistance modes of physical activity for healthy aging as supported by findings in 2007. In line with public health recommendations, several studies in 2007 employed an exercise paradigm that combined both modes of physical activity. While a...

  19. Die aerobe Glykolyse der Tumorzelle

    NASA Astrophysics Data System (ADS)

    Schneider, Friedhelm

    1981-01-01

    A high aerobic glycolysis (aerobic lactate production) is the most significant feature of the energy metabolism of rapidly growing tumor cells. Several mechanisms, which may be different in different cell lines, seem to be involved in this characteristic of energy metabolism of the tumor cell. Changes in the cell membrane leading to increased uptake and utilization of glucose, a high level of fetal types of isoenzymes, a decreased number of mitochondria and a reduced capacity to metabolize pyruvate are some factors which must be taken into consideration. It is not possible to favour one of them at the present time.

  20. Screening and identification of aerobic denitrifiers

    NASA Astrophysics Data System (ADS)

    Shao, K.; Deng, H. M.; Chen, Y. T.; Zhou, H. J.; Yan, G. X.

    2016-08-01

    With the standards of the effluent quality more stringent, it becomes a quite serious problem for municipalities and industries to remove nitrogen from wastewater. Bioremediation is a potential method for the removal of nitrogen and other pollutants because of its high efficiency and low cost. Seven predominant aerobic denitrifiers were screened and characterized from the activated sludge in the CAST unit. Some of these strains remov