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Sample records for aerobic bacterial counts

  1. Improved Aerobic Colony Count Technique for Hydrophobic Grid Membrane Filters

    PubMed Central

    Parrington, Lorna J.; Sharpe, Anthony N.; Peterkin, Pearl I.

    1993-01-01

    The AOAC International official action procedure for performing aerobic colony counts on hydrophobic grid membrane filters (HGMFs) uses Trypticase soy-fast green FCF agar (FGA) incubated for 48 h. Microbial growths are various shades of green on a pale green background, which can cause problems for automated as well as manual counting. HGMFs which had been incubated 24 or 48 h at 35°C on Trypticase soy agar were flooded underneath with 1 to 2 ml of 0.1% triphenyltetrazolium chloride (TTC) solution by simply lifting one corner of the filter while it was still on the agar and adding the reagent. Microbial growths on HGMFs were counted after color had been allowed to develop for 15 min at room temperature. With representative foods, virtually all colonies stained pink to red. Automated electronic counts made by using the MI-100 HGMF Interpreter were easier and more reliable than control HGMF counts made by the AOAC International official action procedure. Manual counting was easier as well because of increased visibility of the microbial growths. Except in the case of dairy products, 24-h TTC counts did not differ significantly from 48-h FGA counts, whereas the FGA counts at 24 h were always significantly lower, indicating that for many food products the HGMF TTC flooding method permits aerobic colony counts to be made after 24 h. PMID:16349033

  2. Aerobic and anaerobic cecal bacterial flora of commercially processed broilers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Differences in the bacterial flora of aerobic and anaerobic cultures of broiler ceca collected from a commercial poultry processing facility were determined. Bacterial isolates from cecal cultures were selected based on the ability of the bacteria to grow in media supplemented with lactate and succ...

  3. Bacterial colony counting by Convolutional Neural Networks.

    PubMed

    Ferrari, Alessandro; Lombardi, Stefano; Signoroni, Alberto

    2015-08-01

    Counting bacterial colonies on microbiological culture plates is a time-consuming, error-prone, nevertheless fundamental task in microbiology. Computer vision based approaches can increase the efficiency and the reliability of the process, but accurate counting is challenging, due to the high degree of variability of agglomerated colonies. In this paper, we propose a solution which adopts Convolutional Neural Networks (CNN) for counting the number of colonies contained in confluent agglomerates, that scored an overall accuracy of the 92.8% on a large challenging dataset. The proposed CNN-based technique for estimating the cardinality of colony aggregates outperforms traditional image processing approaches, becoming a promising approach to many related applications. PMID:26738016

  4. Comparison of epifluorescent viable bacterial count methods

    NASA Technical Reports Server (NTRS)

    Rodgers, E. B.; Huff, T. L.

    1992-01-01

    Two methods, the 2-(4-Iodophenyl) 3-(4-nitrophenyl) 5-phenyltetrazolium chloride (INT) method and the direct viable count (DVC), were tested and compared for their efficiency for the determination of the viability of bacterial populations. Use of the INT method results in the formation of a dark spot within each respiring cell. The DVC method results in elongation or swelling of growing cells that are rendered incapable of cell division. Although both methods are subjective and can result in false positive results, the DVC method is best suited to analysis of waters in which the number of different types of organisms present in the same sample is assumed to be small, such as processed waters. The advantages and disadvantages of each method are discussed.

  5. Automatic counting and classification of bacterial colonies using hyperspectral imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Detection and counting of bacterial colonies on agar plates is a routine microbiology practice to get a rough estimate of the number of viable cells in a sample. There have been a variety of different automatic colony counting systems and software algorithms mainly based on color or gray-scale pictu...

  6. Comparative study of normal and sensitive skin aerobic bacterial populations

    PubMed Central

    Hillion, Mélanie; Mijouin, Lily; Jaouen, Thomas; Barreau, Magalie; Meunier, Pauline; Lefeuvre, Luc; Lati, Elian; Chevalier, Sylvie; Feuilloley, Marc G J

    2013-01-01

    The purpose of this study was to investigate if the sensitive skin syndrome, a frequent skin disorder characterized by abnormal painful reactions to environmental factors in the absence of visible inflammatory response, could be linked to a modification in the skin bacterial population. A total of 1706 bacterial isolates was collected at the levels of the forehead, cheekbone, inner elbow, and lower area of the scapula on the skin of normal and sensitive skin syndrome-suffering volunteers of both sexes and of different ages. Among these isolates, 21 strains were randomly selected to validate in a first step the Matrix-Assisted Laser Desorption/Ionization (MALDI)-Biotyper process as an efficient identification tool at the group and genus levels, by comparison to API® strips and 16S ribosomal RNA gene sequencing identification techniques. In a second step, identification of the skin microbiota isolates by the MALDI-Biotyper tool allowed to pinpoint some differences in terms of bacterial diversity with regard to the collection area, and the volunteer's age and gender. Finally, comparison of the skin microbiota from normal and sensitive skin syndrome-suffering volunteers pointed out gender-related variations but no detectable correlation between a phylum, a genus or a dominant bacterial species and the sensitive skin phenotype. This study reveals that there is no dysbiosis of aerobic cultivable bacteria associated with the sensitive skin syndrome and further demonstrates that the MALDI-Biotyper is a powerful technique that can be efficiently employed to the study of cultivable human skin bacteria. To our knowledge, this is the first study focusing on bacteria in the sensitive skin syndrome. These results are of potential importance for pharmaceutical and cosmetic industries, which are looking for new strategies to treat this multiparametric disorder. PMID:24151137

  7. Comparative study of normal and sensitive skin aerobic bacterial populations.

    PubMed

    Hillion, Mélanie; Mijouin, Lily; Jaouen, Thomas; Barreau, Magalie; Meunier, Pauline; Lefeuvre, Luc; Lati, Elian; Chevalier, Sylvie; Feuilloley, Marc G J

    2013-12-01

    The purpose of this study was to investigate if the sensitive skin syndrome, a frequent skin disorder characterized by abnormal painful reactions to environmental factors in the absence of visible inflammatory response, could be linked to a modification in the skin bacterial population. A total of 1706 bacterial isolates was collected at the levels of the forehead, cheekbone, inner elbow, and lower area of the scapula on the skin of normal and sensitive skin syndrome-suffering volunteers of both sexes and of different ages. Among these isolates, 21 strains were randomly selected to validate in a first step the Matrix-Assisted Laser Desorption/Ionization (MALDI)-Biotyper process as an efficient identification tool at the group and genus levels, by comparison to API(®) strips and 16S ribosomal RNA gene sequencing identification techniques. In a second step, identification of the skin microbiota isolates by the MALDI-Biotyper tool allowed to pinpoint some differences in terms of bacterial diversity with regard to the collection area, and the volunteer's age and gender. Finally, comparison of the skin microbiota from normal and sensitive skin syndrome-suffering volunteers pointed out gender-related variations but no detectable correlation between a phylum, a genus or a dominant bacterial species and the sensitive skin phenotype. This study reveals that there is no dysbiosis of aerobic cultivable bacteria associated with the sensitive skin syndrome and further demonstrates that the MALDI-Biotyper is a powerful technique that can be efficiently employed to the study of cultivable human skin bacteria. To our knowledge, this is the first study focusing on bacteria in the sensitive skin syndrome. These results are of potential importance for pharmaceutical and cosmetic industries, which are looking for new strategies to treat this multiparametric disorder. PMID:24151137

  8. Evaluation of the petrifilm aerobic count plate for enumeration of aerobic marine bacteria from seawater and Caulerpa lentillifera.

    PubMed

    Kudaka, Jun; Horii, Toru; Tamanaha, Koji; Itokazu, Kiyomasa; Nakamura, Masaji; Taira, Katsuya; Nidaira, Minoru; Okano, Sho; Kitahara, Akio

    2010-08-01

    The enumeration and evaluation of the activity of marine bacteria are important in the food industry. However, detection of marine bacteria in seawater or seafood has not been easy. The Petrifilm aerobic count plate (ACP) is a ready-to-use alternative to the traditional enumeration media used for bacteria associated with food. The purpose of this study was to evaluate the usefulness of a simple detection and enumeration method utilizing the Petrifilm ACP for enumeration of aerobic marine bacteria from seawater and an edible seaweed, Caulerpa lentillifera. The efficiency of enumeration of total aerobic marine bacteria on Petrifilm ACP was compared with that using the spread plate method on marine agar with 80 seawater and 64 C. lentillifera samples. With sterile seawater as the diluent, a close correlation was observed between the method utilizing Petrifilm ACP and that utilizing the conventional marine agar (r=0.98 for seawater and 0.91 for C. lentillifera). The Petrifilm ACP method was simpler and less time-consuming than the conventional method. These results indicate that Petrifilm ACP is a suitable alternative to conventional marine agar for enumeration of marine microorganisms in seawater and C. lentillifera samples. PMID:20819367

  9. Aerobic cyanide degradation by bacterial isolates from cassava factory wastewater

    PubMed Central

    Kandasamy, Sujatha; Dananjeyan, Balachandar; Krishnamurthy, Kumar; Benckiser, Gero

    2015-01-01

    Ten bacterial strains that utilize cyanide (CN) as a nitrogen source were isolated from cassava factory wastewater after enrichment in a liquid media containing sodium cyanide (1 mM) and glucose (0.2% w/v). The strains could tolerate and grow in cyanide concentrations of up to 5 mM. Increased cyanide levels in the media caused an extension of lag phase in the bacterial growth indicating that they need some period of acclimatisation. The rate of cyanide removal by the strains depends on the initial cyanide and glucose concentrations. When initial cyanide and glucose concentrations were increased up to 5 mM, cyanide removal rate increased up to 63 and 61 per cent by Bacillus pumilus and Pseudomonas putida. Metabolic products such as ammonia and formate were detected in culture supernatants, suggesting a direct hydrolytic pathway without an intermediate formamide. The study clearly demonstrates the potential of aerobic treatment with cyanide degrading bacteria for cyanide removal in cassava factory wastewaters. PMID:26413045

  10. Site-specific mouth rinsing can improve oral odor by altering bacterial counts

    PubMed Central

    Alqumber, Mohammed A.; Arafa, Khaled A.

    2014-01-01

    Objectives: To determine whether site-specific mouth rinsing with oral disinfectants can improve oral odor beyond the traditional panoral mouth disinfection with mouth rinses by targeting specifically oral malodor implicated anaerobic bacteria Methods: Twenty healthy fasting subjects volunteered for a blinded prospective, descriptive correlational crossover cross-section clinical trial conducted during the month of Ramadan between July and August 2013 in Albaha province in Saudi Arabia involving the application of Listerine® Cool Mint® mouth rinse by either the traditional panoral rinsing method, or a site-specific disinfection method targeting the subgingival and supragingival plaque and the posterior third of the tongue dorsum, while avoiding the remaining locations within the oral cavity. The viable anaerobic and aerobic bacterial counts, volatile sulfur compounds (VSCs) levels, organoleptic assessment of oral odor, and the tongue-coating index were compared at baseline, one, 5, and 9 hours after the treatment. Results: The site-specific disinfection method reduced the VSCs and anaerobic bacterial loads while keeping the aerobic bacterial numbers higher than the traditional panoral rinsing method. Conclusion: Site-specific disinfection can more effectively maintain a healthy oral cavity by predominantly disinfecting the niches of anaerobic bacteria within the oral cavity. PMID:25399224

  11. Automated counting of bacterial colonies by image analysis.

    PubMed

    Chiang, Pei-Ju; Tseng, Min-Jen; He, Zong-Sian; Li, Chia-Hsun

    2015-01-01

    Research on microorganisms often involves culturing as a means to determine the survival and proliferation of bacteria. The number of colonies in a culture is counted to calculate the concentration of bacteria in the original broth; however, manual counting can be time-consuming and imprecise. To save time and prevent inconsistencies, this study proposes a fully automated counting system using image processing methods. To accurately estimate the number of viable bacteria in a known volume of suspension, colonies distributing over the whole surface area of a plate, including the central and rim areas of a Petri dish are taken into account. The performance of the proposed system is compared with verified manual counts, as well as with two freely available counting software programs. Comparisons show that the proposed system is an effective method with excellent accuracy with mean value of absolute percentage error of 3.37%. A user-friendly graphical user interface is also developed and freely available for download, providing researchers in biomedicine with a more convenient instrument for the enumeration of bacterial colonies. PMID:25451456

  12. Reduced Bacterial Colony Count of Anaerobic Bacteria Is Associated with a Worsening in Lung Clearance Index and Inflammation in Cystic Fibrosis

    PubMed Central

    Bradley, Judy M.; Johnston, Elinor; McGrath, Stephanie; McIlreavey, Leanne; Rowan, Stephen; Reid, Alastair; Bradbury, Ian; Einarsson, Gisli

    2015-01-01

    Anaerobic bacteria have been identified in abundance in the airways of cystic fibrosis (CF) subjects. The impact their presence and abundance has on lung function and inflammation is unclear. The aim of this study was to investigate the relationship between the colony count of aerobic and anaerobic bacteria, lung clearance index (LCI), spirometry and C-Reactive Protein (CRP) in patients with CF. Sputum and blood were collected from CF patients at a single cross-sectional visit when clinically stable. Community composition and bacterial colony counts were analysed using extended aerobic and anaerobic culture. Patients completed spirometry and a multiple breath washout (MBW) test to obtain LCI. An inverse correlation between colony count of aerobic bacteria (n = 41, r = -0.35; p = 0.02), anaerobic bacteria (n = 41, r = -0.44, p = 0.004) and LCI was observed. There was an inverse correlation between colony count of anaerobic bacteria and CRP (n = 25, r = -0.44, p = 0.03) only. The results of this study demonstrate that a lower colony count of aerobic and anaerobic bacteria correlated with a worse LCI. A lower colony count of anaerobic bacteria also correlated with higher CRP levels. These results indicate that lower abundance of aerobic and anaerobic bacteria may reflect microbiota disruption and disease progression in the CF lung. PMID:25992575

  13. New evidence for Cu-decorated binary-oxides mediating bacterial inactivation/mineralization in aerobic media.

    PubMed

    Rtimi, S; Pulgarin, C; Bensimon, M; Kiwi, J

    2016-08-01

    Binary oxide semiconductors TiO2-ZrO2 and Cu-decorated TiO2-ZrO2 (TiO2-ZrO2-Cu) uniform films were sputtered on polyester (PES). These films were irradiated under low intensity solar simulated light and led to bacterial inactivation in aerobic and anaerobic media as evaluated by CFU-plate counting. But bacterial mineralization was only induced by TiO2-ZrO2-Cu in aerobic media. The highly oxidative radicals generated on the films surface under light were identified by the use of appropriate scavengers. The hole generated on the TiO2-ZrO2 films is shown to be the main specie leading to bacterial inactivation. TiO2-ZrO2 and Cu-decorated TiO2-ZrO2 films release Zr and Ti <1ppb and Cu 4.6ppb/cm(2) as determined by inductively coupled plasma mass spectrometry (ICP-MS) This level is far below the citotoxicity permitted level allowed for mammalian cells suggesting that bacterial disinfection proceeds through an oligodynamic effect. By Fourier transform attenuated infrared spectroscopy (ATR-FTIR) the systematic shift of the predominating νs(CH2) vibrational-rotational peak making up most of the bacterial cell-wall content in C was monitored. Based on this evidence a mechanism suggested leading to CH bond stretching followed by cell lysis and cell death. Bacterial inactivation cycling was observed on TiO2-ZrO2-Cu showing the stability of these films leading to bacterial inactivation. PMID:27088192

  14. Aerobic bacterial catabolism of persistent organic pollutants - potential impact of biotic and abiotic interaction.

    PubMed

    Jeon, Jong-Rok; Murugesan, Kumarasamy; Baldrian, Petr; Schmidt, Stefan; Chang, Yoon-Seok

    2016-04-01

    Several aerobic bacteria possess unique catabolic pathways enabling them to degrade persistent organic pollutants (POPs), including polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polybrominated diphenylethers (PBDEs), and polychlorinated biphenyls (PCBs). The catabolic activity of aerobic bacteria employed for removal of POPs in the environment may be modulated by several biotic (i.e. fungi, plants, algae, earthworms, and other bacteria) and abiotic (i.e. zero-valent iron, advanced oxidation, and electricity) agents. This review describes the basic biochemistry of the aerobic bacterial catabolism of selected POPs and discusses how biotic and abiotic agents enhance or inhibit the process. Solutions allowing biotic and abiotic agents to exert physical and chemical assistance to aerobic bacterial catabolism of POPs are also discussed. PMID:26851837

  15. Evaluation of the 3M™ Petrifilm™ Rapid Aerobic Count Plate for the Enumeration of Aerobic Bacteria: Collaborative Study, First Action 2015.13.

    PubMed

    Bird, Patrick; Flannery, Jonathan; Crowley, Erin; Agin, James; Goins, David; Jechorek, Robert

    2016-05-01

    The 3M™ Petrifilm™ Rapid Aerobic Count (RAC) Plate is a sample-ready culture medium system containing dual-sensor indicator technology for the rapid quantification of aerobic bacteria in food products. The 3M Petrifilm RAC Plate was compared to the U.S. Food and Drug Administration Bacteriological Analytical Manual (FDA BAM) Chapter 3 (Aerobic Plate Count) for the enumeration of aerobic bacteria in raw easy-peel shrimp and the Standard Methods for the Examination of Dairy Products (SMEDP) Chapter 6 (Standard Plate Count Method) for the enumeration of aerobic bacteria in pasteurized skim milk and instant nonfat dry milk (instant NFDM). The 3M Petrifilm RAC Plate was evaluated using a paired study design in a multilaboratory collaborative study following current AOAC validation guidelines. Three target contamination levels (low, 10-100 CFU/g; medium, 100-1000 CFU/g; and high 1000-10 000 CFU/g) were evaluated for naturally occurring aerobic microflora for each matrix. For raw easy-peel shrimp, duplicate 3M Petrifilm RAC Plates were enumerated after 24 ± 2 h incubation at both 32 and 35°C. Pasteurized skim milk 3M Petrifilm RAC Plates were enumerated after 24 ± 2 h incubation at 32°C, and instant NFDM 3M Petrifilm RAC Plates were enumerated after 48 ± 3 h incubation at 32°C. No statistical difference was observed between 3M Petrifilm RAC Plate and FDA BAM or SMEDP reference methods for each contamination level. PMID:27297837

  16. Bacterial population dynamics in diary waste during aerobic and anaerobic treatment and subsequent storage.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to model a typical dairy waste stream and monitor the chemical and bacterial population dynamics that occur during aerobic or anaerobic treatment and subsequent storage in a simulated lagoon, and compare them to waste held without treatment in a simulated lagoon. Both...

  17. The Influence of Time Spent in Outdoor Play on Daily and Aerobic Step Count in Costa Rican Children

    ERIC Educational Resources Information Center

    Morera Castro, Maria del Rocio

    2011-01-01

    The purpose of this study is to examine the influence of time spent in outdoor play (i.e., on weekday and weekend days) on daily (i.e., average step count) and aerobic step count (i.e., average moderate to vigorous physical activity [MVPA] during the weekdays and weekend days) in fifth grade Costa Rican children. It was hypothesized that: (a)…

  18. Aerobic biotransformation of polybrominated diphenyl ethers (PBDEs) by bacterial isolates

    PubMed Central

    Robrock, Kristin R.; Coelhan, Mehmet; Sedlak, David; Alvarez-Cohen, Lisa

    2009-01-01

    Polybrominated diphenyl ethers (PBDEs) are flame retardants that have been used in consumer products and furniture for three decades. Currently, very little is known about their fate in the environment and specifically about their susceptibility to aerobic biotransformation. Here, we investigated the ability of the polychlorinated biphenyl (PCB) degrading bacteria Rhodococcus jostii RHA1 and Burkholderia xenovorans LB400 to transform mono- through hexa-BDEs at ppb levels. We also tested the PBDE transforming abilities of related strain Rhodococcus sp. RR1 and the ether-degrading Pseudonocardia dioxanivorans CB1190. The two PCB-degrading strains transformed all of the mono- through penta-BDEs and strain LB400 transformed one of the hexa-BDEs. The extent of transformation was inversely proportional to the degree of bromination. Strains RR1 and CB1190 were only able to transform the less brominated mono- and di- BDE congeners. RHA1 released stoichiometric quantities of bromide while transforming mono- and tetra-BDE congeners. LB400 instead converted most of a mono-BDE to a hydroxylated mono-BDE. This is the first report of aerobic transformation of tetra-, penta- and hexa-BDEs as well as the first report of stoichiometric release of bromide during PBDE transformation. PMID:19731666

  19. Enhancement of aerobic biodegradability potential of municipal waste activated sludge by ultrasonic aided bacterial disintegration.

    PubMed

    Kavitha, S; Jessin Brindha, G M; Sally Gloriana, A; Rajashankar, K; Yeom, Ick Tae; Rajesh Banu, J

    2016-01-01

    An investigation was performed to study the influence of ultrasonic aided bacterial disintegration on the aerobic degradability of sludge. In first phase of the study, effective floc disruption was achieved at an ultrasonic specific energy input of 2.45kJ/kg TS with 44.5mg/L of Extracellular Polymeric Substance (EPS) release including 0.035U/mL and 0.025U/mL protease and amylase activity respectively. In second phase, experimental outcomes revealed bacterial disintegration of floc disrupted-sludge showing a maximum solubilization of about 23% and was observed to be superior to bacterially disintegrated (11%) and control (6%), respectively. The result of aerobic biodegradability of ultrasonic aided bacterially pretreated sludge showed volatile solids (VS) degradation of about 40.2%. The kinetic study of aerobic biodegradability through non linear regression modelling reveals that floc disrupted sludge showed better biodegradability with decay constant of about 0.19d(-1) relatively higher than the control (0.14d(-1)) and bacterially disintegrated (0.17d(-1)) sludges. PMID:26479431

  20. Response of the jejunal mucosa of dogs with aerobic and anaerobic bacterial overgrowth to antibiotic therapy.

    PubMed Central

    Batt, R M; McLean, L; Riley, J E

    1988-01-01

    Dogs with naturally occurring aerobic or anaerobic bacterial overgrowth have been examined before and after antibiotic therapy in order to assess reversibility of damage to the jejunal mucosa. Histological changes in peroral jejunal biopsies were relatively minor before and after treatment, but sucrose density gradient centrifugation revealed specific biochemical abnormalities that responded to antibiotic therapy. Aerobic overgrowth was initially associated with a marked loss of the main brush border component of alkaline phosphatase activity; this recovered following treatment, suggesting that aerobic bacteria may cause reversible damage to the hydrophobic region of the brush border membrane. In contrast, anaerobic overgrowth was initially associated with a marked reduction in brush border density, indicative of a considerable fall in the glycoprotein-to-lipid ratio of the membrane. Density increased from 1.17 to 1.21 g/ml after antibiotic therapy, consistent with recovery from this relatively severe damage to the brush border caused by anaerobic bacteria. Reductions in soluble and peroxisomal catalase activities which could compromise mucosal protection against free radicals in dogs with aerobic overgrowth, and a loss of particulate malate dehydrogenase activity indicative of mitochondrial disruption in dogs with anaerobic overgrowth, were also reversed after treatment. These findings indicate that aerobic and anaerobic bacterial overgrowth can result in contrasting but potentially reversible damage to the jejunal mucosa which would not be detected by conventional investigative procedures. PMID:3371716

  1. Broiler carcass bacterial counts after immersion chilling using either a low or high volume of water.

    PubMed

    Northcutt, J K; Cason, J A; Smith, D P; Buhr, R J; Fletcher, D L

    2006-10-01

    A study was conducted to investigate the bacteriological impact of using different volumes of water during immersion chilling of broiler carcasses. Market-aged broilers were processed, and carcasses were cut into left and right halves along the keel bone immediately after the final bird wash. One half of each carcass pair was individually chilled at 4 degrees C in a separate bag containing either 2.1 L/kg (low) or 16.8 L/kg (high) of distilled water. Carcass halves were submersed in a secondary chill tank containing approximately 150 L of an ice-water mix (0.6 degrees C). After chilling for 45 min, carcass halves were rinsed with 100 mL of sterile water for 1 min. Rinses and chill water were analyzed for total aerobic bacteria (APC), Escherichia coli, Enterobacteriaceae, and Campylobacter. After chilling with a low volume of water, counts were 3.7, 2.5, 2.6, and 2.1 log(10) cfu/mL of rinse for APC, E. coli, Enterobacteriaceae, and Campylobacter, respectively. When a high volume of chill water was used, counts were 3.2, 1.7, 1.6, and 1.8 log(10) cfu/mL of rinse for APC, E. coli, Enterobacteriaceae, and Campylobacter, respectively. There was no difference in bacterial counts per milliliter of chill water among treatments. These results show that using additional water during immersion chilling of inoculated broilers will remove more bacteria from the carcass surfaces, but numbers of bacteria per milliliter in the chiller water will remain constant. The bacteriological impact of using more water during commercial immersion chilling may not be enough to offset economic costs. PMID:17012173

  2. Evaluation of a Novel Dry Sheet Culture Method for Rapid Enumeration of Total Aerobic Count in Foods.

    PubMed

    Teramura, Hajime; Iwasaki, Mihoko; Ushiyama, Masashi; Ogihara, Hirokazu

    2015-10-01

    A novel dry sheet culture method (Sanita-kun ACplus; SkACp) for rapid enumeration of total viable count has been developed. This rehydrated plate system comprises an adhesive sheet, nonwoven fabric coated with nutrients, and two types of water absorption polymers. In addition, SkACp facilitates methods for both rapid count (rapid mode: 24-h incubation) and accurate enumeration (standard mode: 48-h incubation) because it not only contains conventional 2,3,5-triphenyltetrazolium chloride but also contains two kinds of new tetrazolium salts for rapid and accurate enumeration of total aerobic count. When SkACp was assessed with 91 microorganisms, 87 strains (95.6%), excluding lactic acid and psychrotrophic bacteria, formed red-colored colonies within 24 h, whereas all microorganisms tested formed colonies within 48 h. The SkACp method, with both 24 and 48 h of incubation, was compared with plate count agar (PCA) and 3M Petrifilm AC (PAC) by using 107 naturally contaminated foods. For all foods tested (n = 107), the linear correlation coefficients of 48-h counts on SkACp compared with PCA and PAC were 0.98 and 0.75, respectively, while the 24-h counts on SkACp compared with PCA and PAC were 0.77 and 0.96, respectively. For foods tested, excluding yogurt and lactic beverages ( n = 101), the linear correlation coefficients of 48-h counts on SkACp compared with PCA and PAC were 0.98 and 0.96, respectively, while the 24-h counts on SkACp compared with PCA and PAC were 0.96 and 0.95, respectively. These results demonstrated that SkACp (48 h) is a useful alternative for the enumeration of the total aerobic count for all foods, whereas SkACp (24 h) was also an effective method for rapid enumeration in foods, excluding yogurt and lactic beverages. PMID:26408139

  3. Hyper-thermophilic aerobic bacterial ecology for space agriculture

    NASA Astrophysics Data System (ADS)

    Oshima, T.; Kanazawa, S.; Moriya, T.; Ishikawa, Y.; Hashimoto, H.; Yamashita, M.; Space Agriculture Task Force, J.

    A material recycling is one of core issues in engineering for habitation on extraterrestrial bodies such as Mars A new composting system has been developed in Japan which utilizes some thermophilic bacteria to attain higher temperature than normally expected in the ordinary composting system Dead body of rat was found to be eaten up by the thermophilic bacteria under aerated condition and oxidized to carbon dioxide and few other inorganics within two hours Ecology of these composting bacteria is structured on the intensive symbiotic interactions among various species that participate in various reaction networks in a concert Complexity in the composting bacteria might be based on multiple interaction and interdependency among participating species and organisms Species identification and phylogeny of symbiotic bacteria and understanding of their ecology have been made Those bacterial systems are active and durable under temperature high in a range of 80 to 100 r C Biological combustion release heat and temperature goes up when air is fed through the reaction bed Since microbial activity decreases at exceeding temperature and release of heat decreases as well temperature in the reacting bed itself-regulated in the range Even though it should be verified composting bacteria themselves are presumed to be safe for human agricultural plant and animal species Their activity is restricted only to the condition under elevated temperature Their activities depend greatly on their symbiotic partners and extreme environment created by them The

  4. [Study of the aerobic bacterial flora of onycolysis and paronychia caused by Candida].

    PubMed

    Robles, A M; Negroni, R; De Hardie, N

    1976-01-01

    The aerobic bacterial flora of 63 cases of onicolysis 78 of paronychis and 5 of onicomadesis produced by yeast-like fungus were studied. Bacterial isolation was carried out in nutrient agar with a concentration of 10 mug/ml of nystatin. These microorganisms were identified following the Otto Bier and Bailey & Scott's techniques (3, 1). Bacterial contamination was very frequent. One species or more were isolated from 93,6% of onicolysis and 97% of paronychis. The onicolysis presented the following flora: "Staphylococcus aureus" in 22 cases, "Staphylococcus epidermidis" in 21, Gram positive sporulated bacilli in 17, "Enterobacteriaceae" in 13, and "Pseudomona aeruginosa" in 6. The paronychial lesions showed the following flora: "Staphylococcus aureus" in 21 cases, "Staphylococcus epidermidis" in 26, Gram positive sporulated bacilli in 17, "Enterobacteriaceae" in 17 and "Pseudomona aeruginosa" in 3. It is important to emphasize that "Pseudomona aeruginosa" was isolated in a few cases of both types of candidal onixis, contrary to usual reports (2, 4, 9). No significant difference between the aerobic bacterial flora of the onicolysis and paronychia was found, that would give an explanation of the existence of these two clinical forms of candidal nails infection. PMID:1035392

  5. Steps Counts among Middle School Students Vary with Aerobic Fitness Level

    ERIC Educational Resources Information Center

    Le Masurier, Guy C.; Corbin, Charles B.

    2006-01-01

    The purpose of this study was to examine if steps/day taken by middle school students varied based on aerobic fitness classification. Middle school students (N = 223; 112 girls, 111 boys) were assigned to three aerobic fitness categories (HIGH, MOD, LOW) based on results of the FITNESSGRAM PACER test. Four weekdays of pedometer monitoring…

  6. Effect of 12-week-long aerobic training programme on body composition, aerobic capacity, complete blood count and blood lipid profile among young women

    PubMed Central

    Nowak, Robert; Jastrzębski, Zbigniew; Zarębska, Aleksandra; Bichowska, Marta; Drobnik-Kozakiewicz, Izabela; Radzimiński, Łukasz; Leońska-Duniec, Agata; Ficek, Krzysztof; Cięszczyk, Paweł

    2015-01-01

    Background Numerous data suggest that aerobic-type exercise improves lipoprotein-lipid profiles, cardiorespiratory fitness and body composition in young women. The aim of this study was to evaluate the biological response to high-low impact aerobic fitness among young women. Materials and methods Thirty-four young women aged 22 (19-24) years were divided into three groups: underweight (N = 10), normal weight (N = 12) and overweight (N = 12). Aerobic capacity, anthropometry and body composition together with complete blood count and lipid profile were determined before and after completion of a 12-week-long training period. Results The training programme caused a significant decrease in weight (by 4.3 kg, P = 0.003), body mass index (by 1.3 kg/m2, P = 0.003), free fat mass (by 2.1 kg, P = 0.002), total body water (by 0.4 kg, P = 0.036), percentage of fat (by 3 percent points, P = 0.002), all analyzed skinfolds thicknesses, as well as the lipid profile in overweight group, and no changes in normal weight group. Significant changes in weight (by 4.2 kg, P = 0.005), body mass index (by 0.9 kg/m2, P = 0.005), crus skinfold thickness (by 3.3 mm, P = 0.028), and in maximum oxygen uptake (by 2.49 mL/kg/min; P = 0.047) were observed among underweight women. No change in total blood count was observed in all groups. Conclusion Twelve-week-long fitness training programme of two alternating styles (low and high impact) has a beneficial effect on overweight young women. PMID:25672474

  7. Developmental hazard assessment with FETAX: Aerobic metabolites in bacterial transformation of naphthalene

    SciTech Connect

    Schultz, T.W.; Dawson, D.A.

    1995-05-01

    The underlying principle of bioremediation is the capability of microorganisms to biodegrade pollutants. When a contaminated site is biotreated, it is usually assumed that the disappearance of the pollutant means a reduction in the toxic effects of the contaminants. However, pollutants can undergo partial biodegradation or biotransformation. Microbial-mediated transformations play a critical role in the toxic effects of pollutants, as any alteration in structure can result in a change in physicochemical properties which influence toxicity. Therefore, a relevant question is; what is the toxicity of accumulative metabolites relative to the parent chemical? One class of chemicals that consistently appears at Superfund hazard waste sites is aromatic hydrocarbons. Studies of the aerobic bacterial metabolism of representative compounds, including benzene, naphthalene, and phenanthrene, have revealed similar oxidative pathways. Bacterial degradation of these aromatic hydrocarbons was initiated by the addition of two molecules of oxygen via a dioxygenase enzyme, with the resulting intermediate being converted to a catechol-like compound. From a biotransformation standpoint, one of the more thoroughly studied aromatic hydrocarbons has been naphthalene. Cerniglia (1984) has identified five major intermediates, 1,2-dihydroxynaphthalene, salicylaldehyde, salicylic acid, gentisic acid and catechol in the aerobic bacterial degradation of naphthalene. In vitro test systems such as the Frog Embryo Teratogenesis Assay - Xenopus (FETAX) provide a time- and resource-effective means for assessing developmental toxicity on a preliminary basis. FETAX is a 96-hr static-renewal system that uses early embryos of the frog Xenopus laevis. The purpose of this investigation was to determine the developmental hazard, using FETAX, of exposure to the model aromatic hydrocarbon, naphthalene, and it`s known major aerobic metabolites from bacterial transformation. 18 refs., 2 tabs.

  8. INTERRELATIONSHIP OF BACTERIAL COUNTS WITH OTHER FINISHED WATER QUALITY PARAMETERS WITHIN DISTRIBUTION SYSTEMS

    EPA Science Inventory

    The objective of this research program was to obtain realistic information concerning the interrelationships between temperature, chlorine, turbidity, coliforms, and Standard Plate Count (SPC) densities present in finished water after treatment and distribution. Bacterial identif...

  9. Biodegradation and detoxification of textile azo dyes by bacterial consortium under sequential microaerophilic/aerobic processes.

    PubMed

    Lade, Harshad; Kadam, Avinash; Paul, Diby; Govindwar, Sanjay

    2015-01-01

    Release of textile azo dyes to the environment is an issue of health concern while the use of microorganisms has proved to be the best option for remediation. Thus, in the present study, a bacterial consortium consisting of Providencia rettgeri strain HSL1 and Pseudomonas sp. SUK1 has been investigated for degradation and detoxification of structurally different azo dyes. The consortium showed 98-99 % decolorization of all the selected azo dyes viz. Reactive Black 5 (RB 5), Reactive Orange 16 (RO 16), Disperse Red 78 (DR 78) and Direct Red 81 (DR 81) within 12 to 30 h at 100 mg L(-1) concentration at 30 ± 0.2 °C under microaerophilic, sequential aerobic/microaerophilic and microaerophilic/aerobic processes. However, decolorization under microaerophilic conditions viz. RB 5 (0.26 mM), RO 16 (0.18 mM), DR 78 (0.20 mM) and DR 81 (0.23 mM) and sequential aerobic/microaerophilic processes viz. RB 5 (0.08 mM), RO 16 (0.06 mM), DR 78 (0.07 mM) and DR 81 (0.09 mM) resulted into the formation of aromatic amines. In distinction, sequential microaerophilic/ aerobic process doesn't show the formation of amines. Additionally, 62-72 % reduction in total organic carbon content was observed in all the dyes decolorized broths under sequential microaerophilic/aerobic processes suggesting the efficacy of method in mineralization of dyes. Notable induction within the levels of azoreductase and NADH-DCIP reductase (97 and 229 % for RB 5, 55 and 160 % for RO 16, 63 and 196 % for DR 78, 108 and 258 % for DR 81) observed under sequential microaerophilic/aerobic processes suggested their critical involvements in the initial breakdown of azo bonds, whereas, a slight increase in the levels of laccase and veratryl alcohol oxidase confirmed subsequent oxidation of formed amines. Also, the acute toxicity assay with Daphnia magna revealed the nontoxic nature of the dye-degraded metabolites under sequential microaerophilic/aerobic processes. As biodegradation under sequential microaerophilic/aerobic

  10. Biodegradation and detoxification of textile azo dyes by bacterial consortium under sequential microaerophilic/aerobic processes

    PubMed Central

    Lade, Harshad; Kadam, Avinash; Paul, Diby; Govindwar, Sanjay

    2015-01-01

    Release of textile azo dyes to the environment is an issue of health concern while the use of microorganisms has proved to be the best option for remediation. Thus, in the present study, a bacterial consortium consisting of Providencia rettgeri strain HSL1 and Pseudomonas sp. SUK1 has been investigated for degradation and detoxification of structurally different azo dyes. The consortium showed 98-99 % decolorization of all the selected azo dyes viz. Reactive Black 5 (RB 5), Reactive Orange 16 (RO 16), Disperse Red 78 (DR 78) and Direct Red 81 (DR 81) within 12 to 30 h at 100 mg L-1 concentration at 30 ± 0.2 °C under microaerophilic, sequential aerobic/microaerophilic and microaerophilic/aerobic processes. However, decolorization under microaerophilic conditions viz. RB 5 (0.26 mM), RO 16 (0.18 mM), DR 78 (0.20 mM) and DR 81 (0.23 mM) and sequential aerobic/microaerophilic processes viz. RB 5 (0.08 mM), RO 16 (0.06 mM), DR 78 (0.07 mM) and DR 81 (0.09 mM) resulted into the formation of aromatic amines. In distinction, sequential microaerophilic/ aerobic process doesn’t show the formation of amines. Additionally, 62-72 % reduction in total organic carbon content was observed in all the dyes decolorized broths under sequential microaerophilic/aerobic processes suggesting the efficacy of method in mineralization of dyes. Notable induction within the levels of azoreductase and NADH-DCIP reductase (97 and 229 % for RB 5, 55 and 160 % for RO 16, 63 and 196 % for DR 78, 108 and 258 % for DR 81) observed under sequential microaerophilic/aerobic processes suggested their critical involvements in the initial breakdown of azo bonds, whereas, a slight increase in the levels of laccase and veratryl alcohol oxidase confirmed subsequent oxidation of formed amines. Also, the acute toxicity assay with Daphnia magna revealed the nontoxic nature of the dye-degraded metabolites under sequential microaerophilic/aerobic processes. As biodegradation under sequential microaerophilic/aerobic

  11. Different binarization processes validated against manual counts of fluorescent bacterial cells.

    PubMed

    Tamminga, Gerrit G; Paulitsch-Fuchs, Astrid H; Jansen, Gijsbert J; Euverink, Gert-Jan W

    2016-09-01

    State of the art software methods (such as fixed value approaches or statistical approaches) to create a binary image of fluorescent bacterial cells are not as accurate and precise as they should be for counting bacteria and measuring their area. To overcome these bottlenecks, we introduce biological significance to obtain a binary image from a greyscale microscopic image. Using our biological significance approach we are able to automatically count about the same number of cells as an individual researcher would do by manual/visual counting. Using the fixed value or statistical approach to obtain a binary image leads to about 20% less cells in automatic counting. In our procedure we included the area measurements of the bacterial cells to determine the right parameters for background subtraction and threshold values. In an iterative process the threshold and background subtraction values were incremented until the number of particles smaller than a typical bacterial cell is less than the number of bacterial cells with a certain area. This research also shows that every image has a specific threshold with respect to the optical system, magnification and staining procedure as well as the exposure time. The biological significance approach shows that automatic counting can be performed with the same accuracy, precision and reproducibility as manual counting. The same approach can be used to count bacterial cells using different optical systems (Leica, Olympus and Navitar), magnification factors (200× and 400×), staining procedures (DNA (Propidium Iodide) and RNA (FISH)) and substrates (polycarbonate filter or glass). PMID:27380963

  12. Effects of Gaseous Ozone Exposure on Bacterial Counts and Oxidative Properties in Chicken and Duck Breast Meat.

    PubMed

    Muhlisin, Muhlisin; Utama, Dicky Tri; Lee, Jae Ho; Choi, Ji Hye; Lee, Sung Ki

    2016-01-01

    The effects of gaseous ozone exposure on the bacterial counts and oxidative properties were evaluated in duck and chicken breast fillets, which were stored under a continuous flux of gaseous ozone (10×10(-6) kg O3/m(3)/h) at 4±1℃ for 4 d. The ozone generator was set to on for 15 min and off for 105 min, and this cyclic timer was set during storage. Ozone effectively reduced the growth of coliform, aerobic and anaerobic bacteria in both chicken and duck breast. However, lipid oxidation occurred faster in duck breast than chicken breast with higher degree of discoloration, TBARS value, and antioxidant enzyme (glutathione peroxidase and catalase) activity decline rates. It is concluded that ozone effectively controlled the growth of bacteria in both chicken and duck breast with less effects on oxidative deterioration in chicken breast. PMID:27433112

  13. Effects of Gaseous Ozone Exposure on Bacterial Counts and Oxidative Properties in Chicken and Duck Breast Meat

    PubMed Central

    Muhlisin, Muhlisin; Utama, Dicky Tri; Lee, Jae Ho; Choi, Ji Hye; Lee, Sung Ki

    2016-01-01

    The effects of gaseous ozone exposure on the bacterial counts and oxidative properties were evaluated in duck and chicken breast fillets, which were stored under a continuous flux of gaseous ozone (10×10−6 kg O3/m3/h) at 4±1℃ for 4 d. The ozone generator was set to on for 15 min and off for 105 min, and this cyclic timer was set during storage. Ozone effectively reduced the growth of coliform, aerobic and anaerobic bacteria in both chicken and duck breast. However, lipid oxidation occurred faster in duck breast than chicken breast with higher degree of discoloration, TBARS value, and antioxidant enzyme (glutathione peroxidase and catalase) activity decline rates. It is concluded that ozone effectively controlled the growth of bacteria in both chicken and duck breast with less effects on oxidative deterioration in chicken breast. PMID:27433112

  14. Effects of Ensiling Fermentation and Aerobic Deterioration on the Bacterial Community in Italian Ryegrass, Guinea Grass, and Whole-crop Maize Silages Stored at High Moisture Content

    PubMed Central

    Li, Yanbing; Nishino, Naoki

    2013-01-01

    The effects of storage period and aerobic deterioration on the bacterial community were examined in Italian ryegrass (IR), guinea grass (GG), and whole-crop maize (WM) silages. Direct-cut forages were stored in a laboratory silo for 3, 7, 14, 28, 56, and 120 d without any additives; live counts, content of fermentation products, and characteristics of the bacterial community were determined. 2,3-Butanediol, acetic acid, and lactic acid were the dominant fermentation products in the IR, GG, and WM silages, respectively. The acetic acid content increased as a result of prolonged ensiling, regardless of the type of silage crop, and the changes were distinctively visible from the beginning of GG ensiling. Pantoea agglomerans, Rahnella aquatilis, and Enterobacter sp. were the major bacteria in the IR silage, indicating that alcoholic fermentation may be due to the activity of enterobacteria. Staphylococcus sciuri and Bacillus pumilus were detected when IR silage was spoiled, whereas between aerobically stable and unstable silages, no differences were seen in the bacterial community at silo opening. Lactococcus lactis was a representative bacterium, although acetic acid was the major fermentation product in the GG silage. Lactobacillus plantarum, Lactobacillus brevis, and Morganella morganii were suggested to be associated with the increase in acetic acid due to prolonged storage. Enterobacter cloacae appeared when the GG silage was spoiled. In the WM silage, no distinctive changes due to prolonged ensiling were seen in the bacterial community. Throughout the ensiling, Weissella paramesenteroides, Weissella confusa, and Klebsiella pneumoniae were present in addition to L. plantarum, L. brevis, and L. lactis. Upon deterioration, Acetobacter pasteurianus, Klebsiella variicola, Enterobacter hormaechei, and Bacillus gibsonii were detected. These results demonstrate the diverse bacterial community that evolves during ensiling and aerobic spoilage of IR, GG, and WM silages

  15. Effects of Ensiling Fermentation and Aerobic Deterioration on the Bacterial Community in Italian Ryegrass, Guinea Grass, and Whole-crop Maize Silages Stored at High Moisture Content.

    PubMed

    Li, Yanbing; Nishino, Naoki

    2013-09-01

    The effects of storage period and aerobic deterioration on the bacterial community were examined in Italian ryegrass (IR), guinea grass (GG), and whole-crop maize (WM) silages. Direct-cut forages were stored in a laboratory silo for 3, 7, 14, 28, 56, and 120 d without any additives; live counts, content of fermentation products, and characteristics of the bacterial community were determined. 2,3-Butanediol, acetic acid, and lactic acid were the dominant fermentation products in the IR, GG, and WM silages, respectively. The acetic acid content increased as a result of prolonged ensiling, regardless of the type of silage crop, and the changes were distinctively visible from the beginning of GG ensiling. Pantoea agglomerans, Rahnella aquatilis, and Enterobacter sp. were the major bacteria in the IR silage, indicating that alcoholic fermentation may be due to the activity of enterobacteria. Staphylococcus sciuri and Bacillus pumilus were detected when IR silage was spoiled, whereas between aerobically stable and unstable silages, no differences were seen in the bacterial community at silo opening. Lactococcus lactis was a representative bacterium, although acetic acid was the major fermentation product in the GG silage. Lactobacillus plantarum, Lactobacillus brevis, and Morganella morganii were suggested to be associated with the increase in acetic acid due to prolonged storage. Enterobacter cloacae appeared when the GG silage was spoiled. In the WM silage, no distinctive changes due to prolonged ensiling were seen in the bacterial community. Throughout the ensiling, Weissella paramesenteroides, Weissella confusa, and Klebsiella pneumoniae were present in addition to L. plantarum, L. brevis, and L. lactis. Upon deterioration, Acetobacter pasteurianus, Klebsiella variicola, Enterobacter hormaechei, and Bacillus gibsonii were detected. These results demonstrate the diverse bacterial community that evolves during ensiling and aerobic spoilage of IR, GG, and WM silages

  16. Characterisation of the aerobic bacterial flora of boid snakes: application of MALDI-TOF mass spectrometry.

    PubMed

    Plenz, Bastian; Schmidt, Volker; Grosse-Herrenthey, Anke; Krüger, Monika; Pees, Michael

    2015-03-14

    The aim of this study was to identify aerobic bacterial isolates from the respiratory tract of boids with matrix-assisted laser desorption ionisation-time-of-flight mass spectrometry (MALDI-TOF MS). From 47 boid snakes, swabs from the oral cavity, tracheal wash samples and, in cases in which postmortem examination was performed, pulmonary tissue samples were taken. Each snake was classified as having inflammation of the respiratory tract and/or oral cavity, or without evidence of inflammation based on combination of clinical, cytological and histopathological findings. Samples collected from the respiratory tract and oral cavity were inoculated onto routine media and bacteria were cultured aerobically. All morphologically distinct individual colonies obtained were analysed using MALDI-TOF MS. Unidentified isolates detected in more than three snakes were selected for further 16S rDNA PCR and sequencing. Among all examined isolates (n=243), 49 per cent (n=119) could be sufficiently speciated using MALDI-TOF MS. Molecular biology revealed several bacterial species that have not been previously described in reptiles. With an average of 6.3 different isolates from the respiratory tract and/or oral cavity, boids with inflammatory disease harboured significantly more bacterial species than boids without inflammatory disease (average 2.8 isolates). PMID:25487809

  17. Biodegradation of Free Phytol by Bacterial Communities Isolated from Marine Sediments under Aerobic and Denitrifying Conditions

    PubMed Central

    Rontani, Jean-François; Bonin, Patricia C.; Volkman, John K.

    1999-01-01

    Biodegradation of (E)-phytol [3,7,11,15-tetramethylhexadec-2(E)-en-1-ol] by two bacterial communities isolated from recent marine sediments under aerobic and denitrifying conditions was studied at 20°C. This isoprenoid alcohol is metabolized efficiently by these two bacterial communities via 6,10,14-trimethylpentadecan-2-one and (E)-phytenic acid. The first step in both aerobic and anaerobic bacterial degradation of (E)-phytol involves the transient production of (E)-phytenal, which in turn can be abiotically converted to 6,10,14-trimethylpentadecan-2-one. Most of the isoprenoid metabolites identified in vitro could be detected in a fresh sediment core collected at the same site as the sediments used for the incubations. Since (E)-phytenal is less sensitive to abiotic degradation at the temperature of the sediments (15°C), the major part of (E)-phytol appeared to be biodegraded in situ via (E)-phytenic acid. (Z)- and (E)-phytenic acids are present in particularly large quantities in the upper section of the core, and their concentrations quickly decrease with depth in the core. This degradation (which takes place without significant production of phytanic acid) is attributed to the involvement of alternating β-decarboxymethylation and β-oxidation reaction sequences induced by denitrifiers. Despite the low nitrate concentration of marine sediments, denitrifying bacteria seem to play a significant role in the mineralization of (E)-phytol. PMID:10584007

  18. A fast molecular nondestructive protocol for evaluating aerobic bacterial load on fresh-cut lettuce.

    PubMed

    Gómez, P; Pagnon, M; Egea-Cortines, M; Artés, F; Weiss, J

    2010-10-01

    Elaboration of minimally processed or fresh-cut vegetables requires a quick and reliable method for detection of bacterial contamination over the recommended limits. PCR-based methods fulfil these requirements, but amplification from DNA preparations of the food product is often hampered due to inhibiting substances. The purpose of this study was to develop a fast quantitative PCR (qPCR)-based method for aerobic bacterial enumeration in fresh-cut lettuce, using as reference the centrifugation water (CW) that comes up during processing instead of the food matrix itself. Comparisons between bacterial numbers on lettuce leaves before processing and bacterial numbers in the CW both for naturally occurring bacterial populations and for artificially inoculated lettuce were performed. On an average, 35% of the natural bacterial population and 64% of inoculated bacteria were recovered in the CW. Bacterial number in CW was proportional to initial lettuce contamination suggesting that measures on CW allow a narrow estimation of lettuce contamination. In qPCR, a 23S rDNA region was amplified from bacterial DNA present in the CW, followed by melting peak analyses and quantification. Enumeration of cell number by qPCR did not differ significantly from plate assay and might therefore replace it. The proposed protocol, which includes sample taking, DNA extraction and qPCR from the CW can be performed within less than 5 h. The resulting quantification might be used as a proxy of initial lettuce contamination, allowing direct intervention measures before fresh-cut commodity is shipped from the factory. PMID:21339159

  19. Aerobic bacterial flora of nesting green turtles (Chelonia mydas) from Tortuguero National Park, Costa Rica.

    PubMed

    Santoro, Mario; Hernández, Giovanna; Caballero, Magaly

    2006-12-01

    Bacteriological examination of 70 nesting green turtles (Chelonia mydas) from Tortuguero National Park, Costa Rica was performed to investigate nasal and cloacal aerobic bacteria. A total of 325 bacterial isolates were obtained, including 10 Gram-negative and three Gram-positive genera. Two hundred thirty-nine were Gram-negative and 86 were Gram-positive isolates. Klebsiella pneumoniae was the most common microbe identified in turtle samples: 27/70 (38.5%) in cloacal, and 33/70 (47.1%) in nasal samples. The Enterobacteriaceae family, including Enterobacter agglomerans, E. cloacae, Escherichia coli, Klebsiella oxytoca, K. pneumoniae, and Serratia marcescens, was the largest Gram-negative group of bacteria recovered and comprised 127 of 239 (53.1%) of the Gram-negative isolates. Staphylococcus species was the largest Gram-positive bacteria group, including S. aureus, S. cromogenes, S. epidermis, and S. intermedius, and made up 63 of 86 (73.2%) of the Gram-positive isolates recovered. The results of this study demonstrate that the aerobic bacterial flora of nesting green turtles at Tortuguero National Park is composed of a very wide spectrum of bacteria, including several potential pathogens. PMID:17315444

  20. Real-time bacterial microcolony counting using on-chip microscopy

    NASA Astrophysics Data System (ADS)

    Jung, Jae Hee; Lee, Jung Eun

    2016-02-01

    Observing microbial colonies is the standard method for determining the microbe titer and investigating the behaviors of microbes. Here, we report an automated, real-time bacterial microcolony-counting system implemented on a wide field-of-view (FOV), on-chip microscopy platform, termed ePetri. Using sub-pixel sweeping microscopy (SPSM) with a super-resolution algorithm, this system offers the ability to dynamically track individual bacterial microcolonies over a wide FOV of 5.7 mm × 4.3 mm without requiring a moving stage or lens. As a demonstration, we obtained high-resolution time-series images of S. epidermidis at 20-min intervals. We implemented an image-processing algorithm to analyze the spatiotemporal distribution of microcolonies, the development of which could be observed from a single bacterial cell. Test bacterial colonies with a minimum diameter of 20 μm could be enumerated within 6 h. We showed that our approach not only provides results that are comparable to conventional colony-counting assays but also can be used to monitor the dynamics of colony formation and growth. This microcolony-counting system using on-chip microscopy represents a new platform that substantially reduces the detection time for bacterial colony counting. It uses chip-scale image acquisition and is a simple and compact solution for the automation of colony-counting assays and microbe behavior analysis with applications in antibacterial drug discovery.

  1. Real-time bacterial microcolony counting using on-chip microscopy

    PubMed Central

    Jung, Jae Hee; Lee, Jung Eun

    2016-01-01

    Observing microbial colonies is the standard method for determining the microbe titer and investigating the behaviors of microbes. Here, we report an automated, real-time bacterial microcolony-counting system implemented on a wide field-of-view (FOV), on-chip microscopy platform, termed ePetri. Using sub-pixel sweeping microscopy (SPSM) with a super-resolution algorithm, this system offers the ability to dynamically track individual bacterial microcolonies over a wide FOV of 5.7 mm × 4.3 mm without requiring a moving stage or lens. As a demonstration, we obtained high-resolution time-series images of S. epidermidis at 20-min intervals. We implemented an image-processing algorithm to analyze the spatiotemporal distribution of microcolonies, the development of which could be observed from a single bacterial cell. Test bacterial colonies with a minimum diameter of 20 μm could be enumerated within 6 h. We showed that our approach not only provides results that are comparable to conventional colony-counting assays but also can be used to monitor the dynamics of colony formation and growth. This microcolony-counting system using on-chip microscopy represents a new platform that substantially reduces the detection time for bacterial colony counting. It uses chip-scale image acquisition and is a simple and compact solution for the automation of colony-counting assays and microbe behavior analysis with applications in antibacterial drug discovery. PMID:26902822

  2. Neutrophil left shift and white blood cell count as markers of bacterial infection.

    PubMed

    Honda, Takayuki; Uehara, Takeshi; Matsumoto, Go; Arai, Shinpei; Sugano, Mitsutoshi

    2016-06-01

    Neutrophil left shift and white blood cell (WBC) count are routine laboratory tests used to assess neutrophil state, which depends on supply from the bone marrow and consumption in the tissues. If WBC count is constant, the presence of left shift indicates an increase of neutrophil consumption that is equal to an increase of production. A decrease in WBC count indicates that neutrophil consumption surpasses supply. During a bacterial infection, large numbers of neutrophils are consumed. Thus, from onset of infection to recovery, dynamic changes occur in WBC count and left shift data, reflecting the mild to serious condition of the bacterial infection. Although various stimuli in healthy and pathological conditions also cause left shift, a change as sudden and significant is only seen in bacterial infection. Left shift does not occur in the extremely early or late phases of infection; therefore, assessing data from a single time point is unsuitable for diagnosing a bacterial infection. We argue that time-series data of left shift and WBC count reflect real-time neutrophil consumption during the course of a bacterial infection, allowing more accurate evaluation of patient condition. PMID:27034055

  3. Antimicrobial susceptibility testing in 90 min by bacterial cell count monitoring

    PubMed Central

    Broeren, M A C; Maas, Y; Retera, E; Arents, N L A

    2013-01-01

    The rise in antimicrobial resistance has become a serious global health problem. Restrictive use of antibiotics seems the only option to temper this accession since research in new antibiotics has halted. Antimicrobial stewardship programmes rely on quick access to susceptibility data. This study evaluated the concept of bacterial cell count monitoring as a fast method to determine susceptibility. Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus strains were tested for amoxicillin/piperacillin and gentamicin by three conventional methods (VITEK2®, Etest® and broth-macrodilution). Bacterial cell count monitoring reliably predicted susceptibility after 90 min for Escherichia coli and after 120 min for Pseudomonas aeruginosa and Staphylococcus aureus without any minor, major or very major discrepancies. Time-to-result was reduced by 74%, 83% and 76%, respectively. Bacterial cell count monitoring shows great potential for rapid susceptibility testing. PMID:22390723

  4. Antimicrobial susceptibility testing in 90 min by bacterial cell count monitoring.

    PubMed

    Broeren, M A C; Maas, Y; Retera, E; Arents, N L A

    2013-03-01

    The rise in antimicrobial resistance has become a serious global health problem. Restrictive use of antibiotics seems the only option to temper this accession since research in new antibiotics has halted. Antimicrobial stewardship programmes rely on quick access to susceptibility data. This study evaluated the concept of bacterial cell count monitoring as a fast method to determine susceptibility. Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus strains were tested for amoxicillin/piperacillin and gentamicin by three conventional methods (VITEK2(®) , Etest(®) and broth-macrodilution). Bacterial cell count monitoring reliably predicted susceptibility after 90 min for Escherichia coli and after 120 min for Pseudomonas aeruginosa and Staphylococcus aureus without any minor, major or very major discrepancies. Time-to-result was reduced by 74%, 83% and 76%, respectively. Bacterial cell count monitoring shows great potential for rapid susceptibility testing. PMID:22390723

  5. Effects of high-energy electron irradiation of chicken meat on Salmonella and aerobic plate count

    SciTech Connect

    Heath, J.L.; Owens, S.L.; Tesch, S.; Hannah, K.W. )

    1990-01-01

    Four experiments were used to determine the effects of high-energy irradiation on the number of aerobic microorganisms and Salmonella on broiler breasts and thighs. Irradiation ranging from 100 to 700 kilorads (krads) was provided by a commercial-scale, electron-beam accelerator. Irradiation of broiler breast and thigh pieces with electron beams at levels of 100, 200, 300, 400, 500, and 600 krads showed that levels as low as 100 krads would eliminate Salmonella. When 33 thighs were tested after irradiation at 200 krads, only one thigh tested presumptive positive. The total number of aerobic organisms was reduced by 2 to 3 log10 cycles at irradiation levels of 100, 200, 300, 400, 500, 600, and 700 krads. Increasing the dose above 100 krads gave little if any additional benefit.

  6. Pyrosequence analysis of bacterial communities in aerobic bioreactors treating polycyclic aromatic hydrocarbon-contaminated soil

    PubMed Central

    Richardson, Stephen D.; Aitken, Michael D.

    2011-01-01

    Two aerobic, lab-scale, slurry-phase bioreactors were used to examine the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil and the associated bacterial communities. The two bioreactors were operated under semi-continuous (draw-and-fill) conditions at a residence time of 35 days, but one was fed weekly and the other monthly. Most of the quantified PAHs, including high-molecular-weight compounds, were removed to a greater extent in the weekly-fed bioreactor, which achieved total PAH removal of 76%. Molecular analyses, including pyrosequencing of 16S rRNA genes, revealed significant shifts in the soil bacterial communities after introduction to the bioreactors and differences in the abundance and types of bacteria in each of the bioreactors. The weekly-fed bioreactor displayed a more stable bacterial community with gradual changes over time, whereas the monthly-fed bioreactor community was less consistent and may have been more strongly influenced by the influx of untreated soil during feeding. Phylogenetic groups containing known PAH-degrading bacteria previously identified through stable-isotope probing of the untreated soil were differentially affected by bioreactor conditions. Sequences from members of the Acidovorax and Sphingomonas genera, as well as the uncultivated ‘‘Pyrene Group 2’’ were abundant in the bioreactors. However, the relative abundances of sequences from the Pseudomonas, Sphingobium, and Pseudoxanthomonas genera, as well as from a group of unclassified anthracene degraders, were much lower in the bioreactors compared to the untreated soil. PMID:21369833

  7. Pyrosequencing analysis of aerobic anoxygenic phototrophic bacterial community structure in the oligotrophic western Pacific Ocean.

    PubMed

    Zheng, Qiang; Liu, Yanting; Steindler, Laura; Jiao, Nianzhi

    2015-04-01

    Aerobic anoxygenic phototrophic bacteria (AAPB) represent a widespread functional bacterial group defined by their obligate aerobic and facultative photoheterotrophic abilities. They are an active part of the marine microbial community as revealed by a large number of previous investigations. Here, we made an in-depth comparison of AAPB community structures in the subsurface water and the upper twilight zone of the western Pacific Ocean using high-throughput sequencing based on the pufM gene. Approximately, 100 000 sequences, grouped into 159 OTUs (94% cut-off value), included 44 and 24 OTUs unique to the subsurface and the upper twilight zone, respectively; 92 OTUs were common to both subsurface and twilight zone, and 3 OTUs were found in all samples. Consistent with previous studies, AAPB belonging to the Gammaproteobacteria were the dominant group in the whole water column, followed by the alphaproteobacterial AAPB. Comparing the relative abundance distribution patterns of different clades, an obvious community-structure separation according to deeper or shallower environment could be observed. Sulfitobacter-like, Loktanella-like, Erythrobacter-like, Dinoroseobacter-like and Gamma-HIMB55-like AAPB preferred the high-light subsurface water, while Methylobacterium-like, 'Citromicrobium'-like, Roseovarius-like and Bradyrhizobium-like AAPB, the dim light environment. PMID:25724533

  8. Bioremediation of textile azo dyes by an aerobic bacterial consortium using a rotating biological contactor.

    PubMed

    Abraham, T Emilia; Senan, Resmi C; Shaffiqu, T S; Roy, Jegan J; Poulose, T P; Thomas, P P

    2003-01-01

    The degradation of an azo dye mixture by an aerobic bacterial consortium was studied in a rotating biological reactor. Laterite pebbles of particle size 850 microm to 1.44 mm were fixed on gramophone records using an epoxy resin on which the developed consortium was immobilized. Rate of degradation, BOD, biomass determination, enzymes involved, and fish bioassay were studied. The RBC has a high efficiency for dye degradation even at high dye concentrations (100 microg/mL) and high flow rate (36 L/h) at alkaline pH and salinity conditions normally encountered in the textile effluents. Bioassays (LD-50) using Thilapia fish in treated effluent showed that the percentage mortality was zero over a period of 96 h, whereas the mortality was 100% in untreated dye water within 26 h. Fish bioassay confirms that the effluent from RBC can be discharged safely to the environment. PMID:12892505

  9. Aerobic digestion of tannery wastewater in a sequential batch reactor by salt-tolerant bacterial strains

    NASA Astrophysics Data System (ADS)

    Durai, G.; Rajasimman, M.; Rajamohan, N.

    2011-09-01

    Among the industries generating hyper saline effluents, tanneries are prominent in India. Hyper saline wastewater is difficult to treat by conventional biological treatment methods. Salt-tolerant microbes can adapt to these conditions and degrade the organics in hyper saline wastewater. In this study, the performance of a bench scale aerobic sequencing batch reactor (SBR) was investigated to treat the tannery wastewater by the salt-tolerant bacterial strains namely Pseudomonas aeruginosa, Bacillus flexus, Exiguobacterium homiense and Styphylococcus aureus. The study was carried out under different operating conditions by changing the hydraulic retention time, organic loading rate and initial substrate concentration. From the results it was found that a maximum COD reduction of 90.4% and colour removal of 78.6% was attained. From this study it was found that the salt-tolerant microorganisms could improve the reduction efficiency of COD and colour of the tannery wastewater.

  10. Intradialytic aerobic cycling exercise alleviates inflammation and improves endothelial progenitor cell count and bone density in hemodialysis patients.

    PubMed

    Liao, Min-Tser; Liu, Wen-Chih; Lin, Fu-Huang; Huang, Ching-Feng; Chen, Shao-Yuan; Liu, Chuan-Chieh; Lin, Shih-Hua; Lu, Kuo-Cheng; Wu, Chia-Chao

    2016-07-01

    Inflammation, endothelial dysfunction, and mineral bone disease are critical factors contributing to morbidity and mortality in hemodialysis (HD) patients. Physical exercise alleviates inflammation and increases bone density. Here, we investigated the effects of intradialytic aerobic cycling exercise on HD patients. Forty end-stage renal disease patients undergoing HD were randomly assigned to either an exercise or control group. The patients in the exercise group performed a cycling program consisting of a 5-minute warm-up, 20 minutes of cycling at the desired workload, and a 5-minute cool down during 3 HD sessions per week for 3 months. Biochemical markers, inflammatory cytokines, nutritional status, the serum endothelial progenitor cell (EPC) count, bone mineral density, and functional capacity were analyzed. After 3 months of exercise, the patients in the exercise group showed significant improvements in serum albumin levels, the body mass index, inflammatory cytokine levels, and the number of cells positive for CD133, CD34, and kinase insert domain-conjugating receptor. Compared with the exercise group, the patients in the control group showed a loss of bone density at the femoral neck and no increases in EPCs. The patients in the exercise group also had a significantly greater 6-minute walk distance after completing the exercise program. Furthermore, the number of EPCs significantly correlated with the 6-minute walk distance both before and after the 3-month program. Intradialytic aerobic cycling exercise programs can effectively alleviate inflammation and improve nutrition, bone mineral density, and exercise tolerance in HD patients. PMID:27399127

  11. 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

  12. Comparison of the biochemical changes in the jejunal mucosa of dogs with aerobic and anaerobic bacterial overgrowth.

    PubMed

    Batt, R M; McLean, L

    1987-11-01

    Subcellular biochemical changes in the jejunal mucosa have been compared in dogs with either aerobic or anaerobic bacterial overgrowth to explore relationships between composition of the flora and mucosal damage. Affected animals comprised 17 German shepherd dogs with chronic diarrhea or weight loss, or both. Analysis of duodenal juice demonstrated aerobic overgrowth in 10 cases, most frequently comprising enterococci and Escherichia coli, and obligate anaerobic overgrowth in 7 cases, most frequently including Clostridia spp. Histologic changes were minimal; however, examination of peroral jejunal biopsy specimens by sucrose density gradient centrifugation revealed specific biochemical abnormalities. In the dogs with aerobic overgrowth, there was a selective loss of brush border alkaline phosphatase activity, and gamma-glutamyl transferase activity was increased, whereas activities of disaccharidases and aminopeptidase N were unaltered. In contrast, anaerobic overgrowth was associated with a reduction in brush border density, indicative of a considerable fall in the glycoprotein-to-lipid ratio of the brush border membrane, whereas brush border enzyme activities were unaltered. There was a loss of peroxisomal catalase activity in dogs with aerobic overgrowth, and an indication of mitochondrial disruption in dogs with anaerobic overgrowth, but little evidence for damage to other subcellular organelles. These findings demonstrate that aerobic and anaerobic overgrowth may be associated with distinct but different mucosal abnormalities particularly affecting the brush border membrane. PMID:2888701

  13. Pectinolytic systems of two aerobic sporogenous bacterial strains with high activity on pectin.

    PubMed

    Soriano, Margarita; Diaz, Pilar; Pastor, F I Javier

    2005-02-01

    Strains Paenibacillus sp. BP-23 and Bacillus sp. BP-7, previously isolated from soil from a rice field, secreted high levels of pectinase activity in media supplemented with pectin. Production of pectinases in strain Paenibacillus sp. BP-23 showed catabolite repression, while in Bacillus sp. BP-7 production of pectin degrading enzymes was not negatively affected by glucose. The two strains showed lyase activities as the predominant pectinases, while hydrolase activity was very low. Analysis of Paenibacillus sp. BP-23 in SDS-polyacrylamide gels and zymograms showed five pectinase activity bands. The strict requirement of Ca(2+) for lyase activity of the strain indicates that correspond to pectate lyases. For Bacillus sp. BP-7, zymograms showed four bands of different size. The strain showed a Ca(2+) requirement for lyase activity on pectate but not on pectin, indicating that the pectinolytic system of Bacillus sp. BP-7 is comprised of pectate lyases and pectin lyases. The results show differences in pectin degrading systems between the two aerobic sporogenous bacterial strains studied. PMID:15717229

  14. Lessons from the organization of a proficiency testing program in food microbiology by interlaboratory comparison: analytical methods in use, impact of methods on bacterial counts and measurement uncertainty of bacterial counts.

    PubMed

    Augustin, Jean-Christophe; Carlier, Vincent

    2006-02-01

    The proficiency testing program in food microbiology RAEMA (Réseau d'Analyses et d'Echanges en Microbiologie des Aliments), created in 1988, currently includes 450 participating laboratories. This interlaboratory comparison establishes proficiency in detection of Salmonella and Listeria monocytogenes, as well as enumeration of aerobic micro-organisms, Enterobacteriaceae, coliforms, beta-glucuronidase-positive Escherichia coli, anaerobic sulfito-reducing bacteria, Clostridium perfringens, coagulase-positive staphylococci, and L. monocytogenes. Twice a year, five units samples are sent to participants to assess their precision and trueness for enumeration and detection of micro-organisms. Most of participating laboratories use standard or validated alternative methods, they were 50-70% in 1994 and, for 5 years, they are 95%. An increasing use of alternative methods was also observed. This phenomenon is all the more significant as standard methods are laborious and time consuming; thus, 50% of the laboratories use alternative methods for the detection of Salmonella and L. monocytogenes. More and more laboratories use ready-to-use media and although the percentage is variable according to the microflora, we can consider that, today, 50-60% of the laboratories participating to the proficiency program only use ready-to-use media. The internal quality assurance programs lead also to an increasing use of media quality controls. The impact of analytical methods on bacterial counts was assessed by grouping together the results obtained by participating laboratories during the 10 last testing schemes from 1999 to 2003. The identified significant factors influencing enumeration results are variable from one microflora to another. Some of them significantly influence many microflora: the plating method (spiral plating or not) is influential for aerobic micro-organisms, Enterobacteriaceae, coliforms, and staphylococci, the type of culture medium and the medium manufacturer is

  15. Disposable bioluminescence-based biosensor for detection of bacterial count in food.

    PubMed

    Luo, Jinping; Liu, Xiaohong; Tian, Qing; Yue, Weiwei; Zeng, Jing; Chen, Guangquan; Cai, Xinxia

    2009-11-01

    A biosensor for rapid detection of bacterial count based on adenosine 5'-triphosphate (ATP) bioluminescence has been developed. The biosensor is composed of a key sensitive element and a photomultiplier tube used as a detector element. The disposable sensitive element consists of a sampler, a cartridge where intracellular ATP is chemically extracted from bacteria, and a microtube where the extracted ATP reacts with the luciferin-luciferase reagent to produce bioluminescence. The bioluminescence signal is transformed into relevant electrical signal by the detector and further measured with a homemade luminometer. Parameters affecting the amount of the extracted ATP, including the types of ATP extractants, the concentrations of ATP extractant, and the relevant neutralizing reagent, were optimized. Under the optimal experimental conditions, the biosensor showed a linear response to standard bacteria in a concentration range from 10(3) to 10(8) colony-forming units (CFU) per milliliter with a correlation coefficient of 0.925 (n=22) within 5min. Moreover, the bacterial count of real food samples obtained by the biosensor correlated well with those by the conventional plate count method. The proposed biosensor, with characteristics of low cost, easy operation, and fast response, provides potential application to rapid evaluation of bacterial contamination in the food industry, environment monitoring, and other fields. PMID:19464252

  16. A THUMBNAIL HISTORY OF HETEROTROPHIC PLATE COUNT (HPC) METHODOLOGY IN THE UNITED STATES

    EPA Science Inventory

    Over the past 100 years, the method of determining the number of bacteria in water, foods or other materials has been termed variously as: bacterial plate count, total plate count, total viable plate count, aerobic plate count, standard plate cound and more recently, heterotrophi...

  17. Bacterial counts associated with sawdust and recycled manure bedding treated with commercial conditioners.

    PubMed

    Hogan, J S; Bogacz, V L; Thompson, L M; Romig, S; Schoenberger, P S; Weiss, W P; Smith, K L

    1999-08-01

    Bacteria counts associated with untreated organic bedding materials were compared with those of bedding treated with either an alkaline commercial bedding conditioner, acidic commercial bedding conditioner, or hydrated lime. Bedding materials were recycled manure and kiln-dried sawdust. The effects of bedding treatments on bacteria counts differed between bedding types. Each of the bedding treatments significantly reduced bacteria in recycled manure prior to use. The alkaline conditioner and hydrated lime effectively inhibited bacteria in recycled manure for 1 d. Bedding counts and teat swabs of cows housed on recycled manure treated with the alkaline conditioner were reduced on d 2. The use of the acid conditioner in recycled manure had little effect on bacteria in bedding. Sawdust differed from recycled manure in that bacteria in untreated sawdust prior to use were minimal, and populations increased rapidly during the first 2 d after use as bedding. The acid conditioner had a bacteriostatic effect in sawdust, evident by the reduction of bacteria on d 2. The alkaline conditioner and hydrated lime did not alter bacteria counts in sawdust compared with untreated sawdust. Antibacterial activity of each conditioner deteriorated between d 2 and d 6 in both beddings. The antibacterial activities of conditioners were related to the pH of bedding materials. The use of commercial bedding conditioners initially reduced bacterial counts; however, the antibacterial effects had diminished between d 2 and 6 after use in bedding. PMID:10480094

  18. Variable effects of oxytetracycline on antibiotic resistance gene abundance and the bacterial community during aerobic composting of cow manure.

    PubMed

    Qian, Xun; Sun, Wei; Gu, Jie; Wang, Xiao-Juan; Sun, Jia-Jun; Yin, Ya-Nan; Duan, Man-Li

    2016-09-01

    Livestock manure is often subjected to aerobic composting but little is known about the variation in antibiotic resistance genes (ARGs) during the composting process under different concentrations of antibiotics. This study compared the effects of three concentrations of oxytetracycline (OTC; 10, 60, and 200mg/kg) on ARGs and the succession of the bacterial community during composting. Very similar trends were observed in the relative abundances (RAs) of each ARG among the OTC treatments and the control during composting. After composting, the RAs of tetC, tetX, sul1, sul2, and intI1 increased 2-43 times, whereas those of tetQ, tetM, and tetW declined by 44-99%. OTC addition significantly increased the absolute abundances and RAs of tetC and intI1, while 200mg/kg OTC also enhanced those of tetM, tetQ, and drfA7. The bacterial community could be grouped according to the composting time under different treatments. The highest concentration of OTC had a more persistent effect on the bacterial community. In the present study, the succession of the bacterial community appeared to have a greater influence on the variation of ARGs during composting than the presence of antibiotics. Aerobic composting was not effective in reducing most of the ARGs, and thus the compost product should be considered as an important reservoir for ARGs. PMID:27179201

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

    PubMed

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

    2015-02-01

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

  20. Multicenter Evaluation of the Bruker MALDI Biotyper CA System for the Identification of Clinical Aerobic Gram-Negative Bacterial Isolates

    PubMed Central

    Faron, Matthew L.; Buchan, Blake W.; Hyke, Josh; Madisen, Neil; Lillie, Jennifer L.; Granato, Paul A.; Wilson, Deborah A.; Procop, Gary W.; Novak-Weekley, Susan; Marlowe, Elizabeth; Cumpio, Joven; Griego-Fullbright, Christen; Kindig, Sandra; Timm, Karen; Young, Stephen; Ledeboer, Nathan A.

    2015-01-01

    The prompt and accurate identification of bacterial pathogens is fundamental to patient health and outcome. Recent advances in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) have revolutionized bacterial identification in the clinical laboratory, but uniform incorporation of this technology in the U.S. market has been delayed by a lack of FDA-cleared systems. In this study, we conducted a multicenter evaluation of the MALDI Biotyper CA (MBT-CA) System (Bruker Daltonics Inc, Billerica, MA) for the identification of aerobic gram-negative bacteria as part of a 510(k) submission to the FDA. A total of 2,263 aerobic gram negative bacterial isolates were tested representing 23 genera and 61 species. Isolates were collected from various clinical sources and results obtained from the MBT-CA System were compared to DNA sequencing and/or biochemical testing. Isolates that failed to report as a "high confidence species ID" [log(score) ≥2.00] were re-tested using an extraction method. The MBT-CA System identified 96.8% and 3.1% of isolates with either a "high confidence" or a "low confidence" [log(score) value between 1.70 and <2.00] species ID, respectively. Two isolates did not produce acceptable confidence scores after extraction. The MBT-CA System correctly identified 99.8% (2,258/2,263) to genus and 98.2% (2,222/2,263) to species level. These data demonstrate that the MBT-CA System provides accurate results for the identification of aerobic gram-negative bacteria. PMID:26529504

  1. Bacterial vaginosis, aerobic vaginitis, vaginal inflammation and major Pap smear abnormalities.

    PubMed

    Vieira-Baptista, P; Lima-Silva, J; Pinto, C; Saldanha, C; Beires, J; Martinez-de-Oliveira, J; Donders, G

    2016-04-01

    The purpose of this investigation was to evaluate the impact of the vaginal milieu on the presence of abnormal Pap smears and a positive human papilloma virus (HPV) test. A cross-sectional study was conducted between June 2014 and May 2015, evaluating the vaginal discharge by fresh wet mount microscopy and comparing these data with Pap smear findings. Wet mount slides were scored for bacterial vaginosis (BV), aerobic vaginitis (AV), presence of Candida and Trichomonas vaginalis. Cytologic evaluation was done on all Pap smears according to the Bethesda criteria. The cobas© HPV Test (Roche) was performed for HPV detection. A total of 622 cases were evaluated. The mean age of the patients was 41.6 ± 10.65 years (range 21-75). Eighty-three women (13.3 %) had a cytology result worse than low-grade squamous intraepithelial lesion (LSIL). When comparing this group with the one with normal or minor [atypical squamous cells of undetermined significance (ASC-US) or LSIL] Pap smear abnormalities, there were no differences in the presence of Candida (32.5 % vs. 33.2 %, p = 1.0), absence of lactobacilli (38.6 % vs. 32.5 %, p = 0.32) or BV (20.5 % vs. 13.2 %, p = 0.09). On the other hand, moderate or severe inflammation (msI) (41.0 % vs. 28.8 %, p = 0,04), moderate or severe AV (msAV) (16.9 % vs. 7.2 %, p = 0.009) and msAV/BV (37.3 % vs. 20.0 %, p = 0.001) were more common in women with such major cervical abnormalities. No significant association was found between deviations of the vaginal milieu and high-risk HPV infection. The presence of msI or msAV, but not BV, is independently associated with an increased risk of major cervical cytological abnormalities, but not with HPV infection. PMID:26810061

  2. Culturable Aerobic and Facultative Anaerobic Intestinal Bacterial Flora of Black Cobra (Naja naja karachiensis) in Southern Pakistan

    PubMed Central

    Iqbal, Junaid; Sagheer, Mehwish; Tabassum, Nazneen; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

    2014-01-01

    Using morphological analysis and biochemical testing, here for the first time, we determined the culturable gut bacterial flora (aerobes and facultative anaerobes) in the venomous Black Cobra (Naja naja karachiensis) from South Asia. The findings revealed that these snakes inhabit potentially pathogenic bacteria including Serratia marcescens, Pseudomonas aeruginosa, Shewanella putrefaciens, Aeromonas hydrophila, Salmonella sp., Moraxella sp., Bacillus sp., Ochrobactrum anthropi, and Providencia rettgeri. These findings are of concern, as injury from snake bite can result in wound infections and tissue necrosis leading to sepsis/necrotizing fasciitis and/or expose consumers of snake meat/medicine in the community to infections. PMID:25002979

  3. Culturable Aerobic and Facultative Anaerobic Intestinal Bacterial Flora of Black Cobra (Naja naja karachiensis) in Southern Pakistan.

    PubMed

    Iqbal, Junaid; Sagheer, Mehwish; Tabassum, Nazneen; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

    2014-01-01

    Using morphological analysis and biochemical testing, here for the first time, we determined the culturable gut bacterial flora (aerobes and facultative anaerobes) in the venomous Black Cobra (Naja naja karachiensis) from South Asia. The findings revealed that these snakes inhabit potentially pathogenic bacteria including Serratia marcescens, Pseudomonas aeruginosa, Shewanella putrefaciens, Aeromonas hydrophila, Salmonella sp., Moraxella sp., Bacillus sp., Ochrobactrum anthropi, and Providencia rettgeri. These findings are of concern, as injury from snake bite can result in wound infections and tissue necrosis leading to sepsis/necrotizing fasciitis and/or expose consumers of snake meat/medicine in the community to infections. PMID:25002979

  4. Enhancement of Bacterial Transport in Aerobic and Anaerobic Environments: Assessing the Effect of Metal Oxide Chemical Heterogeneities

    SciTech Connect

    T.C. Onstott

    2005-09-30

    The goal of our research was to understand the fundamental processes that control microbial transport in physically and chemically heterogeneous aquifers and from this enhanced understanding determine the requirements for successful, field-scale delivery of microorganisms to metal contaminated subsurface sites. Our specific research goals were to determine; (1) the circumstances under which the preferential adsorption of bacteria to Fe, Mn, and Al oxyhydroxides influences field-scale bacterial transport, (2) the extent to which the adhesion properties of bacterial cells affect field-scale bacterial transport, (3) whether microbial Fe(III) reduction can enhance field-scale transport of Fe reducing bacteria (IRB) and other microorganisms and (4) the effect of field-scale physical and chemical heterogeneity on all three processes. Some of the spin-offs from this basic research that can improve biostimulation and bioaugmentation remediation efforts at contaminated DOE sites have included; (1) new bacterial tracking tools for viable bacteria; (2) an integrated protocol which combines subsurface characterization, laboratory-scale experimentation, and scale-up techniques to accurately predict field-scale bacterial transport; and (3) innovative and inexpensive field equipment and methods that can be employed to enhance Fe(III) reduction and microbial transport and to target microbial deposition under both aerobic and anaerobic conditions.

  5. Assessing carbon and nitrogen removal in a novel anoxic-aerobic cyanobacterial-bacterial photobioreactor configuration with enhanced biomass sedimentation.

    PubMed

    de Godos, I; Vargas, V A; Guzmán, H O; Soto, R; García, B; García, P A; Muñoz, R

    2014-09-15

    The carbon and nitrogen removal potential of an innovative anoxic-aerobic photobioreactor configuration operated with both internal and external recyclings was evaluated under different cyanobacterial-bacterial sludge residence times (9-31 days) during the treatment of wastewaters with low C/N ratios. Under optimal operating conditions, the two-stage photobioreactor was capable of providing organic carbon and nitrogen removals over 95% and 90%, respectively. The continuous biomass recycling from the settler resulted in the enrichment and predominance of rapidly-settling cyanobacterial-bacterial flocs and effluent suspended solid concentrations lower than 35 mg VSS L(-1). These flocs exhibited sedimentation rates of 0.28-0.42 m h(-1) but sludge volumetric indexes of 333-430 ml/g. The decoupling between the hydraulic retention time and sludge retention time mediated by the external recycling also avoided the washout of nitrifying bacteria and supported process operation at biomass concentrations of 1000-1500 mg VSS L(-1). The addition of additional NaHCO3 to the process overcame the CO2 limitation resulting from the intense competition for inorganic carbon between cyanobacteria and nitrifying bacteria in the photobioreactor, which supported the successful implementation of a nitrification-denitrification process. Unexpectedly, this nitrification-denitrification process occurred both simultaneously in the photobioreactor alone (as a result of the negligible dissolved oxygen concentrations) and sequentially in the two-stage anoxic-aerobic configuration with internal NO3(-)/NO2(-) recycling. PMID:24880959

  6. A novel denitrifying bacterial isolate that degrades trimethylamine both aerobically and anaerobically via two different pathways.

    PubMed

    Kim, S G; Bae, H S; Lee, S T

    2001-10-01

    The aerobic and anaerobic degradation of trimethylamine by a newly isolated denitrifying bacterium from an enrichment culture with trimethylamine inoculated with activated sludge was studied. Based on 16S rDNA analysis, this strain was identified as a Paracoccus sp. The isolate, strain T231, aerobically degraded trimethylamine, dimethylamine and methylamine and released a stoichiometric amount of ammonium ion into the culture fluid as a metabolic product, indicating that these methylated amines were completely degraded to formaldehyde and ammonia. The strain degraded trimethylamine also under denitrifying conditions and consumed a stoichiometric amount of nitrate, demonstrating that complete degradation of trimethylamine was coupled with nitrate reduction. Cell-free extract prepared from cells grown aerobically on trimethylamine exhibited activities of trimethylamine mono-oxygenase, trimethylamine N-oxide demethylase, dimethylamine mono-oxygenase, and methylamine mono-oxygenase. Cell-free extract from cells grown anaerobically on trimethylamine and nitrate exhibited activities of trimethylamine dehydrogenase and dimethylamine dehydrogenase. These results indicate that strain T231 had two different pathways for aerobic and anaerobic degradation of trimethylamine. This is a new feature for trimethylamine metabolism in denitrifying bacteria. PMID:11685371

  7. The Influence of Pumping on Observed Bacterial Counts in Groundwater Samples: Implications for Sampling Protocol and Water Quality Interpretation

    NASA Astrophysics Data System (ADS)

    Kozuskanich, J.; Novakowski, K.; Anderson, B.

    2008-12-01

    Drinking water quality has become an important issue in Ontario following the events in Walkerton in 2000. Many rural communities are reliant on private groundwater wells for drinking water, and it is the responsibility of the owner to have the water tested to make sure it is safe for human consumption. Homeowners can usually take a sample to the local health unit for total coliform and E. Coli analysis at no charge to determine if the water supply is being tainted by surface water or fecal matter, both of which could indicate the potential for negative impacts on human health. However, is the sample coming out of the tap representative of what is going on the aquifer? The goal of this study is to observe how bacterial counts may vary during the course of well pumping, and how those changing results influence the assessment of water quality. Multiple tests were conducted in bedrock monitoring wells to examine the influence of pumping rate and pumped volume on observed counts of total coliform, E. Coli, fecal streptococcus, fecal coliform and heterotrophic plate count. Bacterial samples were collected frequently during the course of continuous purging events lasting up to 8 hours. Typical field parameters (temperature, salinity, pH, dissolved oxygen and ORP) were also continuously monitored during the course of each test. Common practice in groundwater studies is to wait until these parameters have stabilized or three well volumes have been removed prior to sampling, to ensure the sample is taken from new water entering the well from the aquifer, rather than the original water stored in the borehole prior to the test. In general, most bacterial counts were low, but did go above the drinking water standard of 0 counts/100mL (total coliform and E. Coli) at times during the tests. Results show the greatest variability in the observed bacterial counts at the onset of pumping prior to the removal of three well volumes. Samples taken after the removal of three well

  8. Effect of cleaning procedure and hygienic condition of milking equipment on bacterial count of bulk tank milk.

    PubMed

    Bava, Luciana; Zucali, Maddalena; Sandrucci, Anna; Brasca, Milena; Vanoni, Laura; Zanini, Lucio; Tamburini, Alberto

    2011-05-01

    The aim of the study was to describe the characteristics of cleaning procedures for milking equipment applied in intensive dairy farms in Lombardy (Italy) and to study their relationships with bacterial count of bulk milk and hygienic condition of milking machine components. A group of 22 dairy farms was visited twice (winter and summer) in order to collect bulk tank milk and post-rinse water samples and swabs from liners and milk receiver. Samples were analysed to determine: standard plate count (SPC), laboratory pasteurization count (LPC), psychrotrophic bacteria count (PBC), coliform count (CC) and Escherichia coli. Cleaning procedures were monitored using electronic milk flow meters with specific software for the measurement of the duration of each cleaning phase, circulating solution temperature and electrical conductivity, turbulence and water filling percentage of pipelines. The results showed that farms classified as high and low milk total bacteria count significantly differed both in terms of liners and receiver bacterial contamination and in terms of water temperature reached during the detergent phase of cleaning milking equipment. Significant positive correlations were found among total bacteria count in milk and bacterial contamination of the liners. Maximum water temperature reached during the cleaning cycle of milking equipment was very low (34.4±8.9°C on average); most of the observations (88.6%) corresponded to water temperatures <45°C. Cleaning temperature was related to psychrotrophic bacteria count of milk and post-rinse water and coliform count in liners. Routine check and regulation of water temperature during the washing phase of the milking machine can be a simple and effective way to control one of the main risk factors for bacteriological quality of bulk tank milk. PMID:21371358

  9. Relationship between polymorphonuclear leukocyte count in bronchoalveolar lavage fluid and bacterial content in Gram's stain and bacterial content in final microbiological report.

    PubMed

    Cavrić, Gordana; Mihalić, Slavica Naumovski; Tesanović, Sanda Janković; Dvorsćak, Matea Bogdanović; Erceg, Gorjana; Krkusek, Marijana Rehorić; Bartolek, Dubravka; Jurić, Klara; Nassabain, Khaled; Budimir, Ivan

    2010-03-01

    Eighty samples of bronchoalveolar lavage fluid (BALF) were obtained from the total of 48 patients (22 females and 26 males) and analyzed. Eighteen of those patients were organ transplant recipients. The relationship between polymorphonuclear leukocyte (PMN) count in direct sample and semi quantitative Gram-positive and Gram-negative bacterial content were analyzed in BALF samples. PMN count in direct sample and Gram-positive and Gram-negative bacterial content of the final microbiological report was compared as well. On the total number of samples PMN count in direct samples of BALF was statistically significant regarding the presence of Gram-positive bacteria in the same sample; it was nearly significant regarding the presence of Gram-negative bacteria; and it was statistically significant for the total bacterial content. If BALF samples are divided into those obtained from organ-transplant and those obtained from non-organ-transplant patients, positive, statistically significant relationship is found in the organ-transplant group, more specifically for the relationship between PMNs and total bacterial content. When PMN count in direct microbiological sample was compared with the results of the final microbiological report, statistically significant relationship was found neither with respect to all BALF samples, nor after dividing them into "organ-transplant" and "non-organ-transplant" group. We did not find differences caused by gender. PMID:20437633

  10. Incomplete aerobic degradation of the antidiabetic drug Metformin and identification of the bacterial dead-end transformation product Guanylurea.

    PubMed

    Trautwein, Christoph; Kümmerer, Klaus

    2011-10-01

    Active pharmaceutical ingredients as well as personal care products are detected in increasing prevalence in different environmental compartments such as surface water, groundwater and soil. Still little is known about the environmental fate of these substances. The type II antidiabetic drug Metformin has already been detected in different surface waters worldwide, but concentrations were significantly lower than the corresponding predicted environmental concentration (PEC). In human and mammal metabolism so far no metabolites of Metformin have been identified, so the expected environmental concentrations should be very high. To assess the aerobic biodegradability of Metformin and the possible formation of degradation products, three Organisation of Economic Cooperation and Development (OECD) test series were performed in the present study. In the Closed Bottle test (OECD 301 D), a screening test that simulates the conditions of an environmental surface water compartment, Metformin was classified as not readily biodegradable (no biodegradation). In the Manometric Respiratory test (OEDC 301 F) working with high bacterial density, Metformin was biodegraded in one of three test bottles to 48.7% and in the toxicity control bottle to 57.5%. In the Zahn-Wellens test (OECD 302 B) using activated sludge, Metformin was biodegraded in both test vessels to an extent of 51.3% and 49.9%, respectively. Analysis of test samples by high performance liquid chromatography coupled to multiple stage mass spectrometry (HPLC-MS(n)) showed in the tests vessels were biodegradation was observed full elimination of Metformin and revealed Guanylurea (Amidinourea, Dicyandiamidine) as single and stable aerobic bacterial degradation product. In another Manometric Respiratory test Guanylurea showed no more transformation. Photodegradation of Guanylurea was also negative. A first screening in one of the greatest sewage treatment plant in southern Germany found Metformin with high concentrations

  11. Supramolecular organization of bacterial aerobic respiratory chains: From cells and back.

    PubMed

    Melo, Ana M P; Teixeira, Miguel

    2016-03-01

    Aerobic respiratory chains from all life kingdoms are composed by several complexes that have been deeply characterized in their isolated form. These membranous complexes link the oxidation of reducing substrates to the reduction of molecular oxygen, in a process that conserves energy by ion translocation between both sides of the mitochondrial or prokaryotic cytoplasmatic membranes. In recent years there has been increasing evidence that those complexes are organized as supramolecular structures, the so-called supercomplexes and respirasomes, being available for eukaryotes strong data namely obtained by electron microscopy and single particle analysis. A parallel study has been developed for prokaryotes, based on blue native gels and mass spectrometry analysis, showing that in these more simple unicellular organisms such supercomplexes also exist, involving not only typical aerobic-respiration associated complexes, but also anaerobic-linked enzymes. After a short overview of the data on eukaryotic supercomplexes, we will analyse comprehensively the different types of prokaryotic aerobic respiratory supercomplexes that have been thus far suggested, in both bacteria and archaea. This article is part of a Special Issue entitled Organization and dynamics of bioenergetic systems in bacteria, edited by Prof Conrad Mullineaux. PMID:26546715

  12. AromaDeg, a novel database for phylogenomics of aerobic bacterial degradation of aromatics

    PubMed Central

    Duarte, Márcia; Jauregui, Ruy; Vilchez-Vargas, Ramiro; Junca, Howard; Pieper, Dietmar H.

    2014-01-01

    Understanding prokaryotic transformation of recalcitrant pollutants and the in-situ metabolic nets require the integration of massive amounts of biological data. Decades of biochemical studies together with novel next-generation sequencing data have exponentially increased information on aerobic aromatic degradation pathways. However, the majority of protein sequences in public databases have not been experimentally characterized and homology-based methods are still the most routinely used approach to assign protein function, allowing the propagation of misannotations. AromaDeg is a web-based resource targeting aerobic degradation of aromatics that comprises recently updated (September 2013) and manually curated databases constructed based on a phylogenomic approach. Grounded in phylogenetic analyses of protein sequences of key catabolic protein families and of proteins of documented function, AromaDeg allows query and data mining of novel genomic, metagenomic or metatranscriptomic data sets. Essentially, each query sequence that match a given protein family of AromaDeg is associated to a specific cluster of a given phylogenetic tree and further function annotation and/or substrate specificity may be inferred from the neighboring cluster members with experimentally validated function. This allows a detailed characterization of individual protein superfamilies as well as high-throughput functional classifications. Thus, AromaDeg addresses the deficiencies of homology-based protein function prediction, combining phylogenetic tree construction and integration of experimental data to obtain more accurate annotations of new biological data related to aerobic aromatic biodegradation pathways. We pursue in future the expansion of AromaDeg to other enzyme families involved in aromatic degradation and its regular update. Database URL: http://aromadeg.siona.helmholtz-hzi.de PMID:25468931

  13. Aerobic bacterial pyrite oxidation and acid rock drainage during the Great Oxidation Event.

    PubMed

    Konhauser, Kurt O; Lalonde, Stefan V; Planavsky, Noah J; Pecoits, Ernesto; Lyons, Timothy W; Mojzsis, Stephen J; Rouxel, Olivier J; Barley, Mark E; Rosìere, Carlos; Fralick, Phillip W; Kump, Lee R; Bekker, Andrey

    2011-10-20

    The enrichment of redox-sensitive trace metals in ancient marine sedimentary rocks has been used to determine the timing of the oxidation of the Earth's land surface. Chromium (Cr) is among the emerging proxies for tracking the effects of atmospheric oxygenation on continental weathering; this is because its supply to the oceans is dominated by terrestrial processes that can be recorded in the Cr isotope composition of Precambrian iron formations. However, the factors controlling past and present seawater Cr isotope composition are poorly understood. Here we provide an independent and complementary record of marine Cr supply, in the form of Cr concentrations and authigenic enrichment in iron-rich sedimentary rocks. Our data suggest that Cr was largely immobile on land until around 2.48 Gyr ago, but within the 160 Myr that followed--and synchronous with independent evidence for oxygenation associated with the Great Oxidation Event (see, for example, refs 4-6)--marked excursions in Cr content and Cr/Ti ratios indicate that Cr was solubilized at a scale unrivalled in history. As Cr isotope fractionations at that time were muted, Cr must have been mobilized predominantly in reduced, Cr(III), form. We demonstrate that only the oxidation of an abundant and previously stable crustal pyrite reservoir by aerobic-respiring, chemolithoautotrophic bacteria could have generated the degree of acidity required to solubilize Cr(III) from ultramafic source rocks and residual soils. This profound shift in weathering regimes beginning at 2.48 Gyr ago constitutes the earliest known geochemical evidence for acidophilic aerobes and the resulting acid rock drainage, and accounts for independent evidence of an increased supply of dissolved sulphate and sulphide-hosted trace elements to the oceans around that time. Our model adds to amassing evidence that the Archaean-Palaeoproterozoic boundary was marked by a substantial shift in terrestrial geochemistry and biology. PMID:22012395

  14. Adequacy of Petrifilm™ Aerobic Count plates supplemented with de Man, Rogosa & Sharpe broth and chlorophenol red for enumeration of lactic acid bacteria in salami.

    PubMed

    de Castilho, Natália Parma Augusto; Okamura, Vivian Tiemi; Camargo, Anderson Carlos; Pieri, Fábio Alessandro; Nero, Luís Augusto

    2015-12-01

    The present study aimed to assess the performance of alternative protocols to enumerate lactic acid bacteria (LAB) in salami. Fourteen cultures and two mixed starter cultures were plated using six protocols: 1) Petrifilm™ Aerobic Count (AC) with MRS broth and chlorophenol red (CR), incubated under aerobiosis or 2) under anaerobiosis, 3) MRS agar with CR, 4) MRS agar with bromocresol purple, 5) MRS agar at pH5.7, and 6) All Purpose Tween agar. Samples of salami were obtained and the LAB microbiota was enumerated by plating according protocols 1, 2, 3 and 5. Regression analysis showed a significant correlation between the tested protocols, based on culture counts (p<0.05). Similar results were observed for salami, and no significant differences of mean LAB counts between selected protocols (ANOVA, p>0.05). Colonies were confirmed as LAB, indicating proper selectivity of the protocols. The results showed the adequacy of Petrifilm™ AC supplemented with CR for the enumeration of LAB in salami. PMID:26291606

  15. Biosorption behavior and mechanism of lead (II) from aqueous solution by aerobic granules (AG) and bacterial alginate (BA)

    NASA Astrophysics Data System (ADS)

    Wang, Lin; Li, Yu

    2012-12-01

    Lead (Pb) and its compounds are common pollutants in industrial wastewaters. To develop appropriate Pb2+ treatment technologies, aerobic granules (AG) and bacterial alginates (BA) were studied as alternative biosorbents to remove Pb2+ from aqueous solutions. The biosorption mechanism of AG and BA were further analyzed to determine which functional groups in AG and BA are active in Pb2+ biosorption. In this paper, the Pb2+ biosorption behavior of AG and BA was respectively investigated in batch experiments from the perspectives of the initial pH, contact time, and initial Pb2+ concentration. The results showed that biosorption of Pb2+ by AG and BA occurred within 60min at the initial Pb2+ concentrations (0-150 mg L-1). The actual saturated Pb2+ biosorption capability of AG was 101.97 mg g-1 (dry weight of aerobic granular biomass). When the initial pH was 5, the biosorption capability of AG and BA was highest at the initial Pb2+ concentrations (0-20mg L-1). During the process of Pb2+ biosorption, K+, Ca2+, and Mg2+ were released. The Ion Chromatography (IC) and Fourier Transform Infrared Spectroscopy (FTIR) further highlighted the main role of ion exchange between Ca2+ and Pb2+ and sequestration of Pb2+ with carboxyl (-COO-) of AG and BA. This analogical analysis verifies that BA is responsible for biosorption of Pb2+ by AG. At the same optimal pH, AG cultivated with different carbon source has different Pb2+ biosorption capacity. The Pb2+ biosorption by AG with sodium acetate as the sole carbon source is higher than AG with glucose as carbon source.

  16. Phosphogypsum biotransformation by aerobic bacterial flora and isolated Trichoderma asperellum from Tunisian storage piles.

    PubMed

    Jalali, Jihen; Magdich, Salwa; Jarboui, Raja; Loungou, Mouna; Ammar, Emna

    2016-05-01

    Aerobic microorganisms able to grow on phosphogypsum (PG), characterized by heavy metals accumulation and high acidity were investigated by enrichment cultures. The PG was used at different concentrations, varying from 20 to 200g/L in the enrichment culture medium supplemented with compost and Tamarix roots. This treatment reduced COD and heavy metals PG concentration. An efficient isolated fungus, identified by molecular approach as Trichoderma asperellum, was able to grow on PG as the sole carbon and energy sources at the different experimented concentrations, and to increase the culture media pH of the different PG concentrations used to 8.13. This fact would be the result of alkaline compound released during the fungus PG solubilization. Besides, the heavy metals and COD removal exceeded 52% after 7 days culture. At 200g/LPG concentration, the experimented strain was able to reduce COD by 52.32% and metals concentrations by 73% for zinc, 63.75% for iron and 50% for cadmium. This exhibited the T. asperellum efficiency for heavy metals accumulation and for phosphogypsum bioremediation. PMID:26855183

  17. Robustness of an aerobic metabolically vinyl chloride degrading bacterial enrichment culture.

    PubMed

    Zhao, He-Ping; Schmidt, Kathrin R; Lohner, Svenja; Tiehm, Andreas

    2011-01-01

    Degradation of the lower chlorinated ethenes is crucial to the application of natural attenuation or in situ bioremediation on chlorinated ethene contaminated sites. Recently, within mixtures of several chloroethenes as they can occur in contaminated groundwater inhibiting effects on aerobic chloroethene degradation have been shown. The current study demonstrated that metabolic vinyl chloride (VC) degradation by an enrichment culture originating from groundwater was not affected by an equimolar concentration (50 μM) of cis-1,2-dichloroethene (cDCE). Only cDCE concentrations at a ratio of 2.4:1 (initial cDCE to VC concentration) caused minor inhibition of VC degradation. Furthermore, the degradation of VC was not affected by the presence of trans-1,2-dichloroethene (tDCE), 1,1-dichloroethene (1,1-DCE), trichloroethene (TCE), and tetrachloroethene (PCE) in equimolar concentrations (50 μM). Only cDCE and tDCE were cometabolically degraded in small amounts. The VC-degrading culture demonstrated a broad pH tolerance from 5 to 9 with an optimum between 6 and 7. Results also showed that the culture could degrade VC concentrations up to 1,800 μM (110 mg/L). PMID:22020471

  18. Aerobic Bacterial Community of American Cockroach Periplaneta americana,a Step toward Finding Suitable Paratransgenesis Candidates

    PubMed Central

    Akbari, Sanaz; Oshaghi, Mohammad Ali; Hashemi-Aghdam, Saedeh Sadat; Hajikhani, Sara; Oshaghi, Ghazaleh; Shirazi, Mohammad Hasan

    2015-01-01

    Background: Cockroaches mechanically spread pathogenic agents, however, little is known about their gut microbiota. Identification of midgut microbial community helps targeting novel biological control strategies such as paratransgenesis. Here the bacterial microbiota of Periplaneta americana midgut, were identified and evaluated for finding proper paratransgenesis candidate. Methods: Midgut of specimens were dissected and cultivated in different media. The bacterial isolates were then identified using the phenotypic and 16S-rRNA sequencing methods. Results: The analytical profile index (API) kit showed presence of 11 bacterial species including: Escherichia coli, Shigella flexineri, Citrobacter freundii, E. vulneris, Enterobacter cloacae, Yersinia pseudotuberculosis, Y. intermedia, Leclericia adecarboxylata, Klebsiella oxytoca, K. planticola, and Rahnella aquatilis in the cockroach midguts. The first three species are potentially symbiotic whereas others are transient. The conventional plating method revealed presence of only four isolates of Salmonella, E. coli, and Proteus which in three cases mismatched with API and 16S-rRNA genotyping. The API correctly identified the four isolates as Shigella flexneri, Citrobacter freundii, and E. coli (n= 2). 16S-rRNA sequence analysis confirmed the API results; however the C. freundii sequence was identical with C. murliniae indicating lack of genetic variation in the gene between these two closely related species. Conclusion: A low number of potentially symbiotic bacteria were found in the American cockroach midguts. Among them Enterobacter cloacae is a potential candidate for paratransgenesis approach whereas other bacteria are pathogens and are not useful for the approach. Data analysis showed that identification levels increase from the conventional to API and to genotyping respectively. PMID:26114142

  19. Identification and Quantification of Volatile Chemical Spoilage Indexes Associated with Bacterial Growth Dynamics in Aerobically Stored Chicken.

    PubMed

    Mikš-Krajnik, Marta; Yoon, Yong-Jin; Ukuku, Dike O; Yuk, Hyun-Gyun

    2016-08-01

    Volatile organic compounds (VOCs) as chemical spoilage indexes (CSIs) of raw chicken breast stored aerobically at 4, 10, and 21 °C were identified and quantified using solid phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS). The growth dynamics of total viable count (TVC), psychrotrophs, Pseudomonas spp., lactic acid bacteria (LAB), Brochothrix thermosphacta and H2 S producing bacteria were characterized based on maximum growth rates (μmax ), maximal microbial concentration (Nmax ) and at the moment of microbial shelf life (Svalues ), calculated from Gompertz-fitted growth curves. Pseudomonas spp. was predominant species, while B. thermosphacta was characterized by the highest μmax . The microbiological and sensory shelf lives were estimated based on TVC, Pseudomonas spp., and B. thermosphacta counts and sensory evaluation, respectively. Among 27 VOCs identified by GC-MS in spoiled chicken samples, ethanol (EtOH), 1-butanol-3-methyl (1But-3M), and acetic acid (C2 ) achieved the highest Pearson's correlation coefficients of 0.66, 0.61, and 0.59, respectively, with TVC, regardless of storage temperature. Partial least squares (PLS) regression revealed that the synthesis of 1But-3M and C2 was most likely induced by the metabolic activity of B. thermosphacta and LAB, while EtOH was attributed to Pseudomonas spp. The increase in concentration of selected volatile spoilage markers (EtOH, 1But-3M, and C2 ) in the headspace over spoiled chicken breast was found to be statistically significant (P < 0.05) with TVC growth. These findings highlight the possibility of analyzing the combination of 3 selected spoilage markers: EtOH, 1But-3M, and C2 as rapid evaluation for poultry quality testing using SPME-GC-MS. PMID:27332555

  20. Statistical Evaluation of Electronic and Plate Counts for Estimating Bacterial Populations

    PubMed Central

    Mountney, G. J.; O'malley, J.

    1966-01-01

    Bacteria from cultures of Staphylococcus aureus, Pseudomonas geniculata, and Rhodotorula glutenis were counted by use of an electronic counter and by plate counts from broth cultures at selected periods from 0 to 24 hr. Variations in the two methods were noted, and the results were compared after calculating correlations, coefficients of variation, and nested analyses of variance. It was not possible to determine the absolute accuracy of the two methods; however, the precision of the results obtained with an electronic counter was better than that obtained with plate counting. It appears that electronic counting, because of ease and convenience, provides better comparative counts at a particular stage of growth, especially during the early stages of the growth period, whereas plate counting yields the best results in determining growth curves. PMID:16349683

  1. Aerobic degradation of ibuprofen in batch and continuous reactors by an indigenous bacterial community.

    PubMed

    Fortunato, María Susana; Fuentes Abril, Nancy Piedad; Martinefski, Manuela; Trípodi, Valeria; Papalia, Mariana; Rádice, Marcela; Gutkind, Gabriel; Gallego, Alfredo; Korol, Sonia Edith

    2016-10-01

    Water from six points from the Riachuelo-Matanza basin was analyzed in order to assess ibuprofen biodegradability. In four of them biodegradation of ibuprofen was proved and degrading bacterial communities were isolated. Biodegradation in each point could not be correlated with sewage pollution. The indigenous bacterial community isolated from the point localized in the La Noria Bridge showed the highest degradative capacity and was selected to perform batch and continuous degradation assays. The partial 16S rRNA gene sequence showed that the community consisted of Comamonas aquatica and Bacillus sp. In batch assays the community was capable of degrading 100 mg L(-1) of ibuprofen in 33 h, with a specific growth rate (μ) of 0.21 h(-1). The removal of the compound, as determined by High performance liquid chromatography (HPLC), exceeded 99% of the initial concentration, with a 92.3% removal of Chemical Oxygen Demand (COD). In a down-flow fixed-bed continuous reactor, the community shows a removal efficiency of 95.9% of ibuprofen and 92.3% of COD for an average inlet concentration of 110.4 mg. The reactor was kept in operation for 70 days. The maximal removal rate for the compound was 17.4 g m(-3) d(-1). Scanning electron microscopy was employed to observe biofilm development in the reactor. The ability of the isolated indigenous community can be exploited to improve the treatment of wastewaters containing ibuprofen. PMID:26905769

  2. Effects of topical erythromycin on ecology of aerobic cutaneous bacterial flora.

    PubMed Central

    Vowels, B R; Feingold, D S; Sloughfy, C; Foglia, A N; Konnikov, N; Ordoukhanian, E; Starkey, P; Leyden, J J

    1996-01-01

    We have demonstrated previously that application of topical erythromycin, an antibiotic commonly used for the treatment of acne, results in an increased density of cutaneous erythromycin-resistant (Emr) coagulase-negative staphylococci; however, it is unknown if this increase results in an overall higher density of total cutaneous staphylococci or if upon cessation of erythromycin use, Emr coagulase-negative staphylococci remain at an increased density compared with the pretreatment density. To investigate this, 2% erythromycin or vehicle was applied to each subject's forehead (n = 225) twice a day by laboratory personnel for a period of 6 weeks. Samples were obtained for culture from the forehead, anterior nares, and back of the subjects at baseline and at weeks 6, 9, and 12 of the study. Cultures were performed on differential media. Plates into which erythromycin was incorporated (8 micrograms/ml) were used to identify Emr coagulase-negative staphylococci. The species of all Emr coagulase-negative staphylococci were determined, and an antibiogram for 16 antibiotics was obtained. The baseline prevalence of Emr coagulase-negative staphylococci on the forehead and nose was about 80% at the two study sites, whereas that on the back was 50%. The baseline density of Emr coagulase-negative staphylococci on the forehead, nose, and back was approximately 20% of the total flora. Following 6 weeks of erythromycin treatment, the prevalence of Emr coagulase-negative staphylococci on the forehead and nose was nearly 100% and the densities were 73 and 62%, respectively; the prevalence and density for the back were 78 and 42%, respectively. The most prevalent erythromycin resistance gene expressed by the Emr coagulase-negative staphylococci was ermC. There was no increase in the numbers of Staphylococcus aureus, gram-negative rods, or yeasts, nor was there increased resistance to any other antibiotic except clindamycin. The density of total aerobic organisms also remained

  3. Clinical Characteristics of Aerobic Vaginitis and Its Association to Vaginal Candidiasis, Trichomonas Vaginitis and Bacterial Vaginosis

    PubMed Central

    Jahic, Mahira; Mulavdic, Mirsada; Nurkic, Jasmina; Jahic, Elmir; Nurkic, Midhat

    2013-01-01

    ABSTRACT Aim of the work: Examine clinical characteristics of aerobic vaginitis and mixed infection for the purpose of better diagnostic accuracy and treatment efficiency. Materials and methods: Prospective research has been conducted at Clinic for Gynecology and Obstetrics, Department for Microbiology and Pathology at Polyclinic for laboratory diagnostic and Gynecology and Obstetrics Department at Health Center Sapna. Examination included 100 examinees with the signs of vaginitis. Examination consisted of: anamnesis, clinical, gynecological and microbiological examination of vaginal smear. Results: The average age of the examinees was 32,62±2,6. Examining vaginal smears of the examinees with signs of vaginitis in 96% (N-96) different microorganisms have been isolated, while in 4% (N-4) findings were normal. AV has been found in 51% (N-51) of the examinees, Candida albicans in 17% (N-17), BV in 15% (N-15), Trichomonas vaginalis in 13% (N-13). In 21% (N-21) AV was diagnosed alone while associated with other agents in 30% (N-30). Most common causes of AV are E. coli (N-55) and E. faecalis (N-52). AV and Candida albicanis have been found in (13/30, 43%), Trichomonas vaginalis in (9/30, 30%) and BV (8/30, 26%). Vaginal secretion is in 70,05% (N-36) yellow coloured, red vagina wall is recorded in 31,13% (N-16) and pruritus in 72,54% (N-37). Increased pH value of vagina found in 94,10% (N-48). The average pH value of vaginal environment was 5,15±0,54 and in associated presence of AV and VVC, TV and BV was 5,29±0,56 which is higher value considering presence of AV alone but that is not statistically significant difference (p>0,05). Amino-odor test was positive in 29,94% (N-15) of associated infections. Lactobacilli are absent, while leukocytes are increased in 100% (N-51) of the examinees with AV. Conclusion: AV is vaginal infection similar to other vaginal infections. It is important to be careful while diagnosing because the treatment of AV differentiates from

  4. Bacterially Induced Dolomite Formation in the Presence of Sulfate Ions under Aerobic Conditions

    NASA Astrophysics Data System (ADS)

    Sanchez-Roman, M.; McKenzie, J. A.; Vasconcelos, C.; Rivadeneyra, M.

    2005-12-01

    The origin of dolomite remains a long-standing enigma in sedimentary geology because, although thermodynamically favorable, precipitation of dolomite from modern seawater does not occur. Experiments conducted at elevated temperatures (200 oC) indicated that the presence of small concentrations of sulfate ions inhibits the transformation of calcite to dolomite [1]. Indeed, sulfate ions appeared to inhibit dolomite formation above 2 mM concentration (versus 28 mM in modern seawater). Recently, culture experiments have demonstrated that sulfate-reducing bacteria mediate the precipitation of dolomite at Earth surface conditions in the presence of sustained sulfate ion concentrations [2,3]. Additionally, in a number of modern hypersaline environments, dolomite forms from solutions with high sulfate ion concentrations (2 to 70 times seawater). These observations suggest that the experimentally observed sulfate-ion inhibition [1] may not apply to all ancient dolomite formation. Here, we report aerobic culture experiments conducted at low temperatures (25 and 35 oC) and variable sulfate ion concentrations (0, 0.5, 1 and 2 x seawater values) using moderately halophilic bacteria, Halomonas meridiana. After an incubation period of 15 days, experiments at 35 oC with variable sulfate ion concentrations (0, 0.5 x and seawater values) contained crystals of Ca-dolomite and stochiometric dolomite. The experiment at 35 oC with 2 x seawater sulfate ion concentration produced dolomite crystals after 20 days of incubation. In a parallel set of experiments at 25 oC, precipitation of dolomite was observed after 25 days of incubation in cultures with variable sulfate ion concentrations (0, 0.5 x and seawater values). In the culture with 2 x seawater sulfate ion concentration, dolomite crystals were observed after 30 days. Our study demonstrates that halophilic bacteria (or heterotrophic microorganisms), which do not require sulfate ions for metabolism, can mediate dolomite precipitation

  5. Aerobic degradation of dinitrotoluenes and pathway for bacterial degradation of 2,6-dinitrotoluene

    SciTech Connect

    Nishino, S.F.; Paoli, G.C.; Spain, J.C.

    2000-05-01

    An oxidative pathway for the mineralization of 2,4-dinitrotoluene (2,4-DNT) by Burkholderia sp. strain DNT has been reported previously. The authors report here the isolation of additional strains with the ability to mineralize 2,4-DNT by the same pathway and the isolation and characterization of bacterial strains that mineralize 2,6-dinitrotoluene (2,6-DNT) by a different pathway. Burkholderia cepacia strain JS850 and Hydrogenophaga palleronii strain JS863 grew on 2,6-DNT as the sole source of carbon and nitrogen. The initial steps in the pathway for degradation of 2,6-DNT were determined by simultaneous induction, enzyme assays, and identification of metabolites through mass spectroscopy and nuclear magnetic resonance. 2,6-DNT was converted to 3-methyl-4-nitrocatechol by a dioxygenation reaction accompanied by the release of nitrite. 3-Methyl-4-nitrocatechol was the substrate for extradiol ring cleavage yielding 2-hydroxy-5-nitro-6-oxohepta-2,4-dienoic acid. 2,4-DNT-degrading strains also converted 2,6-DNT to 3-methyl-4-nitrocatechol but did not metabolize the 3-methyl-4-nitrocatechol. Although 2,6-DNT prevented the degradation of 2,4-DNT by 2,4-DNT-degrading strains, the effect was not the result of inhibition of 2,4-DNT dioxygenase by 2,6-DNT or of 4-methyl-5-nitrocatechol monooxygenase by 3-methyl-4-nitrocatechol.

  6. Cloacal aerobic bacterial flora and absence of viruses in free-living slow worms (Anguis fragilis), grass snakes (Natrix natrix) and European Adders (Vipera berus) from Germany.

    PubMed

    Schmidt, Volker; Mock, Ronja; Burgkhardt, Eileen; Junghanns, Anja; Ortlieb, Falk; Szabo, Istvan; Marschang, Rachel; Blindow, Irmgard; Krautwald-Junghanns, Maria-Elisabeth

    2014-12-01

    Disease problems caused by viral or bacterial pathogens are common in reptiles kept in captivity. There is no information available on the incidence of viral pathogens or the physiological cloacal bacterial flora of common free-living reptiles in Germany. Therefore, 56 free-living reptiles including 23 European adders (Vipera berus), 12 grass snakes (Natrix natrix) and 21 slow worms (Anguis fragilis) were investigated on the island Hiddensee in northeastern Germany. Pharyngeal and cloacal swabs were taken immediately after capture. Bacteriological examination was performed from the cloacal swabs to study the aerobic cloacal flora. Molecular biological examination included amplification of DNA or RNA from adeno-, rana- and ferlaviruses as well as culturing on Russell's viper heart cells for virus isolation. Salmonella spp. were isolated from European adders but not from the other reptiles examined. The minimal inhibitory concentration was determined from the isolated Salmonella spp. However, some potentially human pathogenic bacteria, such as Proteus vulgaris, Aeromonas hydrophila, Klebsiella pneumoniae and Escherichia coli were isolated. Viruses were not detected in any of the examined reptiles. To the authors' best knowledge, the present study is the first survey of viral pathogens in free-living snakes and slow worms in Germany and the first survey of cloacal aerobic bacterial flora of slow worms. PMID:24866333

  7. Changes in Aerobic Plate and Escherichia coli-Coliform Counts and in Populations of Inoculated Foodborne Pathogens on Inshell Walnuts during Storage.

    PubMed

    Frelka, John C; Davidson, Gordon R; Harris, Linda J

    2016-07-01

    After harvest, inshell walnuts are dried using low-temperature forced air and are then stored in bins or silos for up to 1 year. To better understand the survival of bacteria on inshell walnuts, aerobic plate counts (APCs) and Escherichia coli?coliform counts (ECCs) were evaluated during commercial storage (10 to 12°C and 63 to 65% relative humidity) over 9 months. APCs decreased by 1.4 to 2.0 log CFU per nut during the first 5 months of storage, and ECCs decreased by 1.3 to 2.2 log CFU per nut in the first month of storage. Through the remaining 4 to 8 months of storage, APCs and ECCs remained unchanged (P > 0.05) or decreased by <0.15 log CFU per nut per month. Similar trends were observed on kernels extracted from the inshell walnuts. APCs and ECCs were consistently and often significantly higher on kernels extracted from visibly broken inshell walnuts than on kernels extracted from visibly intact inshell walnuts. Parameters measured in this study were used to determine the survival of five-strain cocktails of E. coli O157:H7, Listeria monocytogenes, and Salmonella inoculated onto freshly hulled inshell walnuts (∼8 log CFU/g) after simulated commercial drying (10 to 12 h; 40°C) and simulated commercial storage (12 months at 10°C and 65% relative humidity). Populations declined by 2.86, 5.01, and 4.40 log CFU per nut for E. coli O157:H7, L. monocytogenes, and Salmonella, respectively, after drying and during the first 8 days of storage. Salmonella populations changed at a rate of -0.33 log CFU per nut per month between days 8 and 360, to final levels of 2.83 ± 0.79 log CFU per nut. E. coli and L. monocytogenes populations changed by -0.17 log CFU per nut per month and -0.26 log CFU per nut per month between days 8 and 360, respectively. For some samples, E. coli or L. monocytogenes populations were below the limit of detection by plating (0.60 log CFU per nut) by day 183 or 148, respectively; at least one of the six samples was positive at each subsequent

  8. Management of aerobic vaginitis.

    PubMed

    Tempera, Gianna; Furneri, Pio Maria

    2010-01-01

    Aerobic vaginitis is a new nonclassifiable pathology that is neither specific vaginitis nor bacterial vaginosis. The diversity of this microbiological peculiarity could also explain several therapeutic failures when patients were treated for infections identified as bacterial vaginosis. The diagnosis 'aerobic vaginitis' is essentially based on microscopic examinations using a phase-contrast microscope (at ×400 magnification). The therapeutic choice for 'aerobic vaginitis' should take into consideration an antibiotic characterized by an intrinsic activity against the majority of bacteria of fecal origin, bactericidal effect and poor/absent interference with the vaginal microbiota. Regarding the therapy for aerobic vaginitis when antimicrobial agents are prescribed, not only the antimicrobial spectrum but also the presumed ecological disturbance on the anaerobic and aerobic vaginal and rectal microbiota should be taken into a consideration. Because of their very low impact on the vaginal microbiota, kanamycin or quinolones are to be considered a good choice for therapy. PMID:21051843

  9. Variations of both bacterial community and extracellular polymers: the inducements of increase of cell hydrophobicity from biofloc to aerobic granule sludge.

    PubMed

    Guo, Feng; Zhang, Sheng-Hua; Yu, Xin; Wei, Bo

    2011-06-01

    To investigate the inducements of increase of cell hydrophobicity from aerobic biofloc (ABF) and granular sludge (AGS), in this study, as the first time the hydrophilic and hydrophobic bacterial communities were analyzed independently. Meanwhile, the effect of extracellular polymers (EPS) on the cell hydrophobicity is also studied. Few Bacteroidetes were detected (1.35% in ABF and 3.84% in AGS) in hydrophilic bacteria, whereas they are abundant in the hydrophobic cells (47.8% and 43% for ABF and AGS, respectively). The main species of Bacteroidetes changed from class Sphingobacteria to Flavobacteria in AGS. On the other hand, EPS is directly responsible to cell hydrophobicity. For AGS, cell hydrophobicity was sharply decreased after EPS extraction. Both quantity and property of the extracellular protein are related to hydrophobicity. Our results showed the variation of cell hydrophobicity was resulted from variations of both bacterial population and EPS. PMID:21482465

  10. Bacterial Selection during the Formation of Early-Stage Aerobic Granules in Wastewater Treatment Systems Operated Under Wash-Out Dynamics

    PubMed Central

    Weissbrodt, David G.; Lochmatter, Samuel; Ebrahimi, Sirous; Rossi, Pierre; Maillard, Julien; Holliger, Christof

    2012-01-01

    Aerobic granular sludge is attractive for high-rate biological wastewater treatment. Biomass wash-out conditions stimulate the formation of aerobic granules. Deteriorated performances in biomass settling and nutrient removal during start-up have however often been reported. The effect of wash-out dynamics was investigated on bacterial selection, biomass settling behavior, and metabolic activities during the formation of early-stage granules from activated sludge of two wastewater treatment plants (WWTP) over start-up periods of maximum 60 days. Five bubble-column sequencing batch reactors were operated with feast-famine regimes consisting of rapid pulse or slow anaerobic feeding followed by aerobic starvation. Slow-settling fluffy granules were formed when an insufficient superficial air velocity (SAV; 1.8 cm s−1) was applied, when the inoculation sludge was taken from a WWTP removing organic matter only, or when reactors were operated at 30°C. Fast-settling dense granules were obtained with 4.0 cm s−1 SAV, or when the inoculation sludge was taken from a WWTP removing all nutrients biologically. However, only carbon was aerobically removed during start-up. Fluffy granules and dense granules were displaying distinct predominant phylotypes, namely filamentous Burkholderiales affiliates and Zoogloea relatives, respectively. The latter were predominant in dense granules independently from the feeding regime. A combination of insufficient solid retention time and of leakage of acetate into the aeration phase during intensive biomass wash-out was the cause for the proliferation of Zoogloea spp. in dense granules, and for the deterioration of BNR performances. It is however not certain that Zoogloea-like organisms are essential in granule formation. Optimal operation conditions should be elucidated for maintaining a balance between organisms with granulation propensity and nutrient removing organisms in order to form granules with BNR activities in short

  11. Effect of TiO2 nanoparticles on aerobic granulation of algal-bacterial symbiosis system and nutrients removal from synthetic wastewater.

    PubMed

    Li, Bing; Huang, Wenli; Zhang, Chao; Feng, Sisi; Zhang, Zhenya; Lei, Zhongfang; Sugiura, Norio

    2015-01-01

    The influence of TiO2 nanoparticles (TiO2-NPs) (10-50mg/L) on aerobic granulation of algal-bacterial symbiosis system was investigated by using two identical sequencing batch reactors (SBRs). Although little adverse effect was observed on their nitritation efficiency (98-100% in both reactors), algal-bacterial granules in the control SBR (Rc) gradually lost stability mainly brought about by algae growth. TiO2-NPs addition to RT was found to enhance the granulation process achieving stable and compact algal-bacterial granules with remarkably improved nitratation thus little nitrite accumulation in RT when influent TiO2-NPs⩾30mg/L. Despite almost similar organics and phosphorus removals obtained in both reactors, the stably high nitratation efficiency in addition to much stable granular structure in RT suggests that TiO2-NPs addition might be a promising remedy for the long-term operation of algal-bacterial granular system, most probably attributable to the stimulated excretion of extracellular polymeric substances and less filamentous TM7. PMID:25855527

  12. Effect of omeprazole on intragastric bacterial counts, nitrates, nitrites, and N-nitroso compounds.

    PubMed Central

    Verdu, E; Viani, F; Armstrong, D; Fraser, R; Siegrist, H H; Pignatelli, B; Idström, J P; Cederberg, C; Blum, A L; Fried, M

    1994-01-01

    Previous studies have suggested that profound inhibition of gastric acid secretion may increase exposure to potentially carcinogenic N-nitroso compounds. The aim of this study was to find out if the proton pump inhibitor omeprazole (20 mg daily) is associated with increased concentrations of potentially carcinogenic N-nitroso compounds in gastric juice. The volume of gastric contents, number of bacteria, and concentrations of nitrates, nitrites, and N-nitroso compounds was determined in gastric aspirates obtained after an overnight fast in 14 healthy volunteers (7M:7F) after one week of treatment with placebo, and one and two weeks' treatment with omeprazole. Median bacterial concentrations were 1.0 x 10(4) (range 5.0 x 10(3)-5.0 x 10(6)) colony forming units (CFU)/ml after one weeks' treatment with placebo and increased significantly to 4.0 x 10(5) (0-3.3 x 10(7)) CFU/ml after two weeks' treatment with omeprazole (p < 0.05). A similar increase was seen in the concentration of nitrate reducing bacteria. There was no difference in the volume of gastric aspirates after treatment with omeprazole when compared with placebo (65 (29-155) ml v 42 (19-194) ml). The concentration of N-nitroso compounds was 0.13 (0-1.0) mumol/l after two weeks of omeprazole, which was not significantly different from that seen with placebo (0.15 (0-0.61) mumol/l). There was also no increase in the concentrations of nitrates or nitrites. It is concluded that omeprazole (20 mg once daily) for two weeks in healthy volunteers is associated with gastric bacterial proliferation but does not increase concentrations of N-nitroso compounds. PMID:8174980

  13. Water quality parameters and total aerobic bacterial and vibrionaceae loads in eastern oysters (Crassostrea virginica) from oyster gardening sites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oyster gardening is a practice designed to restore habitat for marine life and to improve water quality. This study determined physical and chemical water quality parameters at two oyster gardening sites in the Delaware Inland Bays and compared them with total aerobic bacteria and Vibrionaceae conc...

  14. Farm management factors associated with bulk tank total bacterial count in Irish dairy herds during 2006/07

    PubMed Central

    2009-01-01

    Research has shown that total bacterial count (TBC), which is the bacterial growth per ml of milk over a fixed period of time, can be decreased by good hygiene and farm management practices. The objective of the current study was to quantify the associations between herd management factors and bulk tank TBC in Irish spring calving, grass-based dairy herds. The relationship between bulk tank TBC and farm management and infrastructure was examined using data from 400 randomly selected Irish dairy farms where the basal diet was grazed grass. Herd management factors associated with bulk tank TBC were identified using linear models with herd annual total bacterial score (i.e., arithmetic mean of the natural logarithm of bulk tank TBC) included as the dependent variable. All herd management factors were individually analysed in a separate regression model, that included an adjustment for geographical location of the farm. A multiple stepwise regression model was subsequently developed. Median bulk tank TBC for the sample herds was 18,483 cells/ml ranging from 10,441 to 130,458 cells/ml. Results from the multivariate analysis indicated that the following management practices were associated with low TBC; use of heated water in the milking parlour; participation in a milk recording scheme; and tail clipping of cows at a frequency greater than once per year. Increased level of hygiene of the parlour and cubicles were also associated with lower TBC. Herd management factors associated with bulk tank TBC in Irish grazing herds were generally in agreement with most previous studies from confinement systems of milk production. PMID:21851723

  15. Risk factors for bulk milk somatic cell counts and total bacterial counts in smallholder dairy farms in the 10th region of Chile.

    PubMed

    van Schaik, G; Green, L E; Guzmán, D; Esparza, H; Tadich, N

    2005-01-01

    We investigated the principal management factors that influenced bulk milk somatic cell count (BMSCC) and total bacterial count (TBC) of smallholder dairy farms in the 10th region of Chile. One hundred and fifty smallholder milk producers were selected randomly from 42 milk collection centres (MCCs). In April and May of 2002, all farms were visited and a detailed interview questionnaire on dairy-cow management related to milk quality was conducted. In addition, the BMSCC and TBC results from the previous 2 months' fortnightly tests were obtained from the MCCs. The mean BMSCC and TBC were used as the dependent variables in the analyses and were normalised by a natural-logarithm transformation (LN). All independent management variables were categorised into binary outcomes and present (=1) was compared with absent (=0). Biserial correlations were calculated between the LNBMSCC or LNTBC and the management factors of the smallholder farms. Management factors with correlations with P0.05) factors. A random MCC effect was included in the models to investigate the importance of clustering of herds within MCC. In the null model for mean LNTBC, the random effect of MCCs was highly significant. It was explained by: milk collected once a day or less compared with collection twice a day, not cleaning the bucket after milking mastitic cows versus cleaning the bucket and cooling milk in a vat of water versus not cooling milk or using ice or a bulk tank to cool milk. Other factors that increased the LNTBC were a waiting yard with a soil or gravel floor versus concrete, use of plastic buckets for milking instead of metal, not feeding California mastitis test (CMT)-positive milk to calves and cows of dual-purpose breed. The final model explained 35% of the variance. The model predicted that a herd that complied with all the management practices had a mean

  16. The effect of anaerobic-aerobic and feast-famine cultivation pattern on bacterial diversity during poly-β-hydroxybutyrate production from domestic sewage sludge.

    PubMed

    Liu, Changli; Liu, Di; Qi, Yingjie; Zhang, Ying; Liu, Xi; Zhao, Min

    2016-07-01

    The main objective of this work was to investigate the influence of different oxygen supply patterns on poly-β-hydroxybutyrate (PHB) yield and bacterial community diversity. The anaerobic-aerobic (A/O) sequencing batch reactors (SBR1) and feast-famine (F/F) SBR2 were used to cultivate activated sludge to produce PHB. The mixed microbial communities were collected and analyzed after 3 months cultivation. The PHB maximum yield was 64 wt% in SBR1 and 53 wt% in SBR2. Pyrosequencing analysis 16S rRNA gene of two microbial communities indicated there were nine and four bacterial phyla in SBR1 and SBR2, respectively. Specifically, Proteobacteria (36.4 % of the total bacterial community), Actinobacteria (19.7 %), Acidobacteria (14.1 %), Firmicutes (4.4 %), Bacteroidetes (1.7 %), Cyanobacteria/Chloroplast (1.5 %), TM7 (0.8 %), Gemmatimonadetes (0.2 %), and Nitrospirae (0.1 %) were present in SBR1. Proteobacteria (94.2 %), Bacteroidetes (2.9 %), Firmicutes (1.9 %), and Actinobacteria (0.7 %) were present in SBR2. Our results indicated the SBR1 fermentation system was more stable than that of SBR2 for PHB accumulation. PMID:26996908

  17. Culture-Independent Analysis of Bacterial Fuel Contamination Provides Insight into the Level of Concordance with the Standard Industry Practice of Aerobic Cultivation ▿ †

    PubMed Central

    White, Judith; Gilbert, Jack; Hill, Graham; Hill, Edward; Huse, Susan M.; Weightman, Andrew J.; Mahenthiralingam, Eshwar

    2011-01-01

    Bacterial diversity in contaminated fuels has not been systematically investigated using cultivation-independent methods. The fuel industry relies on phenotypic cultivation-based contaminant identification, which may lack accuracy and neglect difficult-to-culture taxa. By the use of industry practice aerobic cultivation, 16S rRNA gene sequencing, and strain genotyping, a collection of 152 unique contaminant isolates from 54 fuel samples was assembled, and a dominance of Pseudomonas (21%), Burkholderia (7%), and Bacillus (7%) was demonstrated. Denaturing gradient gel electrophoresis (DGGE) of 15 samples revealed Proteobacteria and Firmicutes to be the most abundant phyla. When 16S rRNA V6 gene pyrosequencing of four selected fuel samples (indicated by “JW”) was performed, Betaproteobacteria (42.8%) and Gammaproteobacteria (30.6%) formed the largest proportion of reads; the most abundant genera were Marinobacter (15.4%; JW57), Achromobacter (41.6%; JW63), Burkholderia (80.7%; JW76), and Halomonas (66.2%; JW78), all of which were also observed by DGGE. However, the Clostridia (38.5%) and Deltaproteobacteria (11.1%) identified by pyrosequencing in sample JW57 were not observed by DGGE or aerobic culture. Genotyping revealed three instances where identical strains were found: (i) a Pseudomonas sp. strain recovered from 2 different diesel fuel tanks at a single industrial site; (ii) a Mangroveibacter sp. strain isolated from 3 biodiesel tanks at a single refinery site; and (iii) a Burkholderia vietnamiensis strain present in two unrelated automotive diesel samples. Overall, aerobic cultivation of fuel contaminants recovered isolates broadly representative of the phyla and classes present but lacked accuracy by overrepresenting members of certain groups such as Pseudomonas. PMID:21602386

  18. Culture-independent analysis of bacterial fuel contamination provides insight into the level of concordance with the standard industry practice of aerobic cultivation.

    PubMed

    White, Judith; Gilbert, Jack; Hill, Graham; Hill, Edward; Huse, Susan M; Weightman, Andrew J; Mahenthiralingam, Eshwar

    2011-07-01

    Bacterial diversity in contaminated fuels has not been systematically investigated using cultivation-independent methods. The fuel industry relies on phenotypic cultivation-based contaminant identification, which may lack accuracy and neglect difficult-to-culture taxa. By the use of industry practice aerobic cultivation, 16S rRNA gene sequencing, and strain genotyping, a collection of 152 unique contaminant isolates from 54 fuel samples was assembled, and a dominance of Pseudomonas (21%), Burkholderia (7%), and Bacillus (7%) was demonstrated. Denaturing gradient gel electrophoresis (DGGE) of 15 samples revealed Proteobacteria and Firmicutes to be the most abundant phyla. When 16S rRNA V6 gene pyrosequencing of four selected fuel samples (indicated by "JW") was performed, Betaproteobacteria (42.8%) and Gammaproteobacteria (30.6%) formed the largest proportion of reads; the most abundant genera were Marinobacter (15.4%; JW57), Achromobacter (41.6%; JW63), Burkholderia (80.7%; JW76), and Halomonas (66.2%; JW78), all of which were also observed by DGGE. However, the Clostridia (38.5%) and Deltaproteobacteria (11.1%) identified by pyrosequencing in sample JW57 were not observed by DGGE or aerobic culture. Genotyping revealed three instances where identical strains were found: (i) a Pseudomonas sp. strain recovered from 2 different diesel fuel tanks at a single industrial site; (ii) a Mangroveibacter sp. strain isolated from 3 biodiesel tanks at a single refinery site; and (iii) a Burkholderia vietnamiensis strain present in two unrelated automotive diesel samples. Overall, aerobic cultivation of fuel contaminants recovered isolates broadly representative of the phyla and classes present but lacked accuracy by overrepresenting members of certain groups such as Pseudomonas. PMID:21602386

  19. Vertical and Horizontal Variations in the Physiological Diversity of the Aerobic Chemoheterotrophic Bacterial Microflora in Deep Southeast Coastal Plain Subsurface Sediments

    PubMed Central

    Balkwill, D. L.; Fredrickson, J. K.; Thomas, J. M.

    1989-01-01

    Aerobic chemoheterotrophic bacteria were isolated from surface soils and coastal plain subsurface (including deep aquifer) sediments (depths to 265 m) at a study site near Aiken, S.C., by plating on concentrated and dilute media. Morphologically distinct colonies were purified, and their responses to 21 selected physiological tests were determined. These isolates were quite diverse; 626 physiologically distinct types (i.e., types with a unique pattern of responses to the 21 tests) were detected among the 1,112 isolates obtained. Physiologically distinct types were isolated on concentrated and dilute media (only 11% overlap between the groups); isolates from surface soils and subsurface sediments were also quite different (only 3% overlap). The surface soil isolates more readily utilized all but 1 of 12 carbon sources offered, and a significantly larger proportion of them hydrolyzed esculin and gelatin. Only 4% of the subsurface isolates fermented glucose, even though 82% of them could use it aerobically. l-Malate and d-gluconate were utilized by at least 75% of the subsurface isolates, and seven other carbon sources were used by at least 40% of them. Subsurface isolates from different geological formations (depths) and, to a lesser extent, from the same geological formation at different boreholes differed distinctly in their group responses to certain physiological tests. Moreover, sediments from different depths and boreholes contained physiologically distinct types of bacteria. Thus, considerable bacterial diversity was observed in coastal plain subsurface sediments, even within defined geological formations. PMID:16347902

  20. Evaluation of wastewater treatment in a novel anoxic-aerobic algal-bacterial photobioreactor with biomass recycling through carbon and nitrogen mass balances.

    PubMed

    Alcántara, Cynthia; Domínguez, Jesús M; García, Dimas; Blanco, Saúl; Pérez, Rebeca; García-Encina, Pedro A; Muñoz, Raúl

    2015-09-01

    Algal-bacterial symbiosis, implemented in an innovative anoxic-aerobic photobioreactor configuration with biomass recycling, supported an efficient removal of total organic carbon (86-90%), inorganic carbon (57-98%) and total nitrogen (68-79%) during synthetic wastewater treatment at a hydraulic and sludge retention times of 2 days and 20 days, respectively. The availability of inorganic carbon in the photobioreactor, determined by its supply in the wastewater and microalgae activity, governed the extent of nitrogen removal by assimilation or nitrification-denitrification. Unexpectedly, nitrate production was negligible despite the high dissolved oxygen concentrations, denitrification being only based on nitrite reduction. Biomass recycling resulted in the enrichment of rapidly settling algal flocs, which supported effluent total suspended solid concentrations below the European Union maximum discharge limits. Finally, the maximum nitrous oxide emissions recorded were far below the emission factors reported for wastewater treatment plants, confirming the environmental sustainability of this innovative photobioreactor in terms of global warming impact. PMID:25989093

  1. Solubilization and bio-conjugation of quantum dots and bacterial toxicity assays by growth curve and plate count.

    PubMed

    Park, Soonhyang; Chibli, Hicham; Nadeau, Jay

    2012-01-01

    previous study, we showed that coupling of antibiotics to CdTe can increase toxicity to bacteria but decrease toxicity to mammalian cells, due to decreased production of reactive oxygen species from the conjugates. Although it is unlikely that cadmium-containing compounds will be approved for use in humans, such preparations could be used for disinfection of surfaces or sterilization of water. In this protocol, we give a straightforward approach to solubilizing CdTe QDs with mercaptopropionic acid (MPA). The QDs are ready to use within an hour. We then demonstrate coupling to an antimicrobial agent. The second part of the protocol demonstrates a 96-well bacterial inhibition assay using the conjugated and unconjugated QDs. The optical density is read over many hours, permitting the effects of QD addition and light exposure to be evaluated immediately as well as after a recovery period. We also illustrate a colony count for quantifying bacterial survival. PMID:22824953

  2. The Campylobacter jejuni MarR-like transcriptional regulators RrpA and RrpB both influence bacterial responses to oxidative and aerobic stresses

    PubMed Central

    Gundogdu, Ozan; da Silva, Daiani T.; Mohammad, Banaz; Elmi, Abdi; Mills, Dominic C.; Wren, Brendan W.; Dorrell, Nick

    2015-01-01

    The ability of the human intestinal pathogen Campylobacter jejuni to respond to oxidative stress is central to bacterial survival both in vivo during infection and in the environment. Re-annotation of the C. jejuni NCTC11168 genome revealed the presence of two MarR-type transcriptional regulators Cj1546 and Cj1556, originally annotated as hypothetical proteins, which we have designated RrpA and RrpB (regulator of response to peroxide) respectively. Previously we demonstrated a role for RrpB in both oxidative and aerobic (O2) stress and that RrpB was a DNA binding protein with auto-regulatory activity, typical of MarR-type transcriptional regulators. In this study, we show that RrpA is also a DNA binding protein and that a rrpA mutant in strain 11168H exhibits increased sensitivity to hydrogen peroxide oxidative stress. Mutation of either rrpA or rrpB reduces catalase (KatA) expression. However, a rrpAB double mutant exhibits higher levels of resistance to hydrogen peroxide oxidative stress, with levels of KatA expression similar to the wild-type strain. Mutation of either rrpA or rrpB also results in a reduction in the level of katA expression, but this reduction was not observed in the rrpAB double mutant. Neither the rrpA nor rrpB mutant exhibits any significant difference in sensitivity to either cumene hydroperoxide or menadione oxidative stresses, but both mutants exhibit a reduced ability to survive aerobic (O2) stress, enhanced biofilm formation and reduced virulence in the Galleria mellonella infection model. The rrpAB double mutant exhibits wild-type levels of biofilm formation and wild-type levels of virulence in the G mellonella infection model. Together these data indicate a role for both RrpA and RrpB in the C. jejuni peroxide oxidative and aerobic (O2) stress responses, enhancing bacterial survival in vivo and in the environment. PMID:26257713

  3. Flow Cytometry Analysis Using Sysmex UF-1000i Classifies Uropathogens Based on Bacterial, Leukocyte, and Erythrocyte Counts in Urine Specimens among Patients with Urinary Tract Infections

    PubMed Central

    Rydén, Patrik

    2014-01-01

    Urinary tract infections (UTIs) are the second most common bacterial infection. Urine culture is the gold standard for diagnosis, but new techniques, such as flow cytometry analysis (FCA), have been introduced. The aim of the present study was to evaluate FCA characteristics regarding bacteriuria, leukocyturia, and erythrocyturia in relation to cultured uropathogens in specimens from patients with a suspected UTI. We also wanted to evaluate whether the FCA characteristics can identify uropathogens prior to culture. From a prospective study, 1,587 consecutive urine specimens underwent FCA prior to culture during January and February 2012. Outpatients and inpatients (79.6% and 19.4%, respectively) were included, of whom women represented 67.5%. In total, 620 specimens yielded growth, of which Escherichia coli represented 65%, Enterococcus spp. 8%, Klebsiella spp. 7%, and Staphylococcus spp. 5%. For the uropathogens, the outcome of FCA was compared against the results for specimens with E. coli and those with a negative culture. E. coli had high bacterial (median, 17,914/μl), leukocyte (median, 348/μl), and erythrocyte (median, 23/μl) counts. With the exception of Klebsiella spp., the majority of the uropathogens had considerable or significantly lower bacterial counts than that of E. coli. High leukocyte counts were found in specimens with Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa, and group C streptococci. Elevated erythrocyte counts were found for P. vulgaris, P. aeruginosa, and group C streptococci, as well as for Staphylococcus saprophyticus. In essence, FCA adds new information about the bacterial, leukocyte, and erythrocyte counts in urine specimens for different uropathogens. Based on FCA characteristics, uropathogens can be classified and identified prior to culture. E. coli and Klebsiella spp. have similar FCA characteristics. PMID:25472486

  4. Flow cytometry analysis using sysmex UF-1000i classifies uropathogens based on bacterial, leukocyte, and erythrocyte counts in urine specimens among patients with urinary tract infections.

    PubMed

    Monsen, Tor; Rydén, Patrik

    2015-02-01

    Urinary tract infections (UTIs) are the second most common bacterial infection. Urine culture is the gold standard for diagnosis, but new techniques, such as flow cytometry analysis (FCA), have been introduced. The aim of the present study was to evaluate FCA characteristics regarding bacteriuria, leukocyturia, and erythrocyturia in relation to cultured uropathogens in specimens from patients with a suspected UTI. We also wanted to evaluate whether the FCA characteristics can identify uropathogens prior to culture. From a prospective study, 1,587 consecutive urine specimens underwent FCA prior to culture during January and February 2012. Outpatients and inpatients (79.6% and 19.4%, respectively) were included, of whom women represented 67.5%. In total, 620 specimens yielded growth, of which Escherichia coli represented 65%, Enterococcus spp. 8%, Klebsiella spp. 7%, and Staphylococcus spp. 5%. For the uropathogens, the outcome of FCA was compared against the results for specimens with E. coli and those with a negative culture. E. coli had high bacterial (median, 17,914/μl), leukocyte (median, 348/μl), and erythrocyte (median, 23/μl) counts. With the exception of Klebsiella spp., the majority of the uropathogens had considerable or significantly lower bacterial counts than that of E. coli. High leukocyte counts were found in specimens with Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa, and group C streptococci. Elevated erythrocyte counts were found for P. vulgaris, P. aeruginosa, and group C streptococci, as well as for Staphylococcus saprophyticus. In essence, FCA adds new information about the bacterial, leukocyte, and erythrocyte counts in urine specimens for different uropathogens. Based on FCA characteristics, uropathogens can be classified and identified prior to culture. E. coli and Klebsiella spp. have similar FCA characteristics. PMID:25472486

  5. Isolation of high-salinity-tolerant bacterial strains, Enterobacter sp., Serratia sp., Yersinia sp., for nitrification and aerobic denitrification under cyanogenic conditions.

    PubMed

    Mpongwana, N; Ntwampe, S K O; Mekuto, L; Akinpelu, E A; Dyantyi, S; Mpentshu, Y

    2016-01-01

    Cyanides (CN(-)) and soluble salts could potentially inhibit biological processes in wastewater treatment plants (WWTPs), such as nitrification and denitrification. Cyanide in wastewater can alter metabolic functions of microbial populations in WWTPs, thus significantly inhibiting nitrifier and denitrifier metabolic processes, rendering the water treatment processes ineffective. In this study, bacterial isolates that are tolerant to high salinity conditions, which are capable of nitrification and aerobic denitrification under cyanogenic conditions, were isolated from a poultry slaughterhouse effluent. Three of the bacterial isolates were found to be able to oxidise NH(4)-N in the presence of 65.91 mg/L of free cyanide (CN(-)) under saline conditions, i.e. 4.5% (w/v) NaCl. The isolates I, H and G, were identified as Enterobacter sp., Yersinia sp. and Serratia sp., respectively. Results showed that 81% (I), 71% (G) and 75% (H) of 400 mg/L NH(4)-N was biodegraded (nitrification) within 72 h, with the rates of biodegradation being suitably described by first order reactions, with rate constants being: 4.19 h(-1) (I), 4.21 h(-1) (H) and 3.79 h(-1) (G), respectively, with correlation coefficients ranging between 0.82 and 0.89. Chemical oxygen demand (COD) removal rates were 38% (I), 42% (H) and 48% (G), over a period of 168 h with COD reduction being highest at near neutral pH. PMID:27148718

  6. Fate of Escherichia coli O26 in Corn Silage Experimentally Contaminated at Ensiling, at Silo Opening, or after Aerobic Exposure, and Protective Effect of Various Bacterial Inoculants▿

    PubMed Central

    Dunière, Lysiane; Gleizal, Audrey; Chaucheyras-Durand, Frédérique; Chevallier, Isabelle; Thévenot-Sergentet, Delphine

    2011-01-01

    Shiga toxin-producing Escherichia coli (STEC) strains are responsible for human illness. Ruminants are recognized as a major reservoir of STEC, and animal feeds, such as silages, have been pointed out as a possible vehicle for the spread of STEC. The present study aimed to monitor the fate of pathogenic E. coli O26 strains in corn material experimentally inoculated (105 CFU/g) during ensiling, just after silo opening, and after several days of aerobic exposure. The addition of 3 bacterial inoculants, Propionibacterium sp., Lactobacillus buchneri, and Leuconostoc mesenteroides (106 CFU/g), was evaluated for their abilities to control these pathogens. The results showed that E. coli O26 could not survive in corn silage 5 days postensiling, and the 3 inoculants tested did not modify the fate of pathogen survival during ensiling. In the case of direct contamination at silo opening, E. coli O26 could be totally eradicated from corn silage previously inoculated with Leuconostoc mesenteroides. The combination of proper ensiling techniques and the utilization of selected bacterial inoculants appears to represent a good strategy to guarantee nutritional qualities of cattle feed while at the same time limiting the entry of pathogenic E. coli into the epidemiological cycle to improve the microbial safety of the food chain. PMID:21984243

  7. Aerobic bacterial oral flora of garter snakes: development of normal flora and pathogenic potential for snakes and humans.

    PubMed Central

    Goldstein, E J; Agyare, E O; Vagvolgyi, A E; Halpern, M

    1981-01-01

    Garter snakes that are used for scientific laboratory studies or kept as exotic pets often become ill and die early in captivity. They may also act as reservoirs of potential human pathogens or transmit infection to man. A total of 126 strains of aerobic and facultative bacteria, most potential human and snake pathogens, were isolated from 82 garter snake oropharyngeal cultures. Coagulase-negative Staphylococcus species were the most common species isolated. Acinetobacter calcoaceticus var. anitratus, Hafnia alvei, Arizona hinshawii, Salmonella species, Shigella species, Klebsiella oxytoca, and Pseudomonas aeruginosa were among the potential pathogens isolated. The spectrum of bacteria with potential for causing oral and pulmonary infections in garter snakes is greater than has been previously appreciated. Garter snakes should also be considered reservoirs of human pathogens, and appropriate precautions should be taken by laboratory personnel and pet owners. PMID:7240404

  8. Enzymes Involved in the Aerobic Bacterial Degradation of N-Heteroaromatic Compounds: Molybdenum Hydroxylases and Ring-Opening 2,4-Dioxygenases

    NASA Astrophysics Data System (ADS)

    Fetzner, S.

    Many N-heteroaromatic compounds are utilized by micro-organisms as a source of carbon (and nitrogen) and energy. The aerobic bacterial degradation of these growth substrates frequently involves several hydroxylation steps and subsequent dioxygenolytic cleavage of (di)hydroxy-substituted heteroaromatic intermediates to aliphatic metabolites which finally are channeled into central metabolic pathways. As a rule, the initial bacterial hydroxylation of a N-heteroaromatic compound is catalyzed by a molybdenum hydroxylase, which uses a water molecule as source of the incorporated oxygen. The enzyme's redox-active centers - the active site molybdenum ion coordinated to a distinct pyranopterin cofactor, two different [2Fe2S] centers, and in most cases, flavin adenine dinucleotide - transfer electrons from the N-heterocyclic substrate to an electron acceptor, which for many molybdenum hydroxylases is still unknown. Ring-opening 2,4-dioxygenases involved in the bacterial degradation of quinaldine and 1H-4-oxoquinoline catalyze the cleavage of two carbon-carbon bonds with concomitant formation of carbon monoxide. Since they contain neither a metal center nor an organic cofactor, and since they do not show any sequence similarity to known oxygenases, these unique dioxygenases form a separate enzyme family. Quite surprisingly, however, they appear to be structurally and mechanistically related to enzymes of the α/β hydrolase fold superfamily. Microbial enzymes are a great resource for biotechnological applications. Microbial strains or their enzymes may be used for degradative (bioremediation) or synthetic (biotransformation) purposes. Modern bioremediation or biotransformation strategies may even involve microbial catalysts or strains designed by protein engineering or pathway engineering. Prerequisite for developing such modern tools of biotechnology is a comprehensive understanding of microbial metabolic pathways, of the structure and function of enzymes, and of the

  9. Comprehensive Proteomic and Metabolomic Signatures of Nontypeable Haemophilus influenzae-Induced Acute Otitis Media Reveal Bacterial Aerobic Respiration in an Immunosuppressed Environment.

    PubMed

    Harrison, Alistair; Dubois, Laura G; St John-Williams, Lisa; Moseley, M Arthur; Hardison, Rachael L; Heimlich, Derek R; Stoddard, Alexander; Kerschner, Joseph E; Justice, Sheryl S; Thompson, J Will; Mason, Kevin M

    2016-03-01

    A thorough understanding of the molecular details of the interactions between bacteria and host are critical to ultimately prevent disease. Recent technological advances allow simultaneous analysis of host and bacterial protein and metabolic profiles from a single small tissue sample to provide insight into pathogenesis. We used the chinchilla model of human otitis media to determine, for the first time, the most expansive delineation of global changes in protein and metabolite profiles during an experimentally induced disease. After 48 h of infection with nontypeable Haemophilus influenzae, middle ear tissue lysates were analyzed by high-resolution quantitative two-dimensional liquid chromatography-tandem mass spectrometry. Dynamic changes in 105 chinchilla proteins and 66 metabolites define the early proteomic and metabolomic signature of otitis media. Our studies indicate that establishment of disease coincides with actin morphogenesis, suppression of inflammatory mediators, and bacterial aerobic respiration. We validated the observed increase in the actin-remodeling complex, Arp2/3, and experimentally showed a role for Arp2/3 in nontypeable Haemophilus influenzae invasion. Direct inhibition of actin branch morphology altered bacterial invasion into host epithelial cells, and is supportive of our efforts to use the information gathered to modify outcomes of disease. The twenty-eight nontypeable Haemophilus influenzae proteins identified participate in carbohydrate and amino acid metabolism, redox homeostasis, and include cell wall-associated metabolic proteins. Quantitative characterization of the molecular signatures of infection will redefine our understanding of host response driven developmental changes during pathogenesis. These data represent the first comprehensive study of host protein and metabolite profiles in vivo in response to infection and show the feasibility of extensive characterization of host protein profiles during disease. Identification of

  10. Biodegradation and detoxification of melanoidin from distillery effluent using an aerobic bacterial strain SAG5 of Alcaligenes faecalis.

    PubMed

    Santal, Anita Rani; Singh, N P; Saharan, Baljeet Singh

    2011-10-15

    Distillery effluent retains very dark brown color even after anaerobic treatment due to presence of various water soluble, recalcitrant and coloring compounds mainly melanoidins. In laboratory conditions, melanoidin decolorizing bacteria was isolated and optimized the cultural conditions at various incubation temperatures, pH, carbon sources, nitrogen sources and combined effect of both carbon and nitrogen sources. The optimum decolorization (72.6 ± 0.56%) of melanoidins was achieved at pH 7.5 and temperature 37 °C on 5th day of cultivation. The toxicity evaluation with mung bean (Vigna radiata) revealed that the raw distillery effluent was environmentally highly toxic as compared to biologically treated distillery effluent, which indicated that the effluent after bacterial treatment is environmentally safe. This proves to be novel biological treatment technique for biodegradation and detoxification of melanoidin from distillery effluent using the bacterial strain SAG(5). PMID:21880418

  11. [Identification of a high ammonia nitrogen tolerant and heterotrophic nitrification-aerobic denitrification bacterial strain TN-14 and its nitrogen removal capabilities].

    PubMed

    Xin, Xin; Yao, Li; Lu, Lei; Leng, Lu; Zhou, Ying-Qin; Guo, Jun-Yuan

    2014-10-01

    A new strain of high ammonia nitrogen tolerant and heterotrophic nitrification-aerobic denitrification bacterium TN-14 was isolated from the environment. Its physiological and biochemical characteristics and molecular identification, performences of heterotrophic nitrification-aerobic, the abilities of resistance to ammonia nitrogen as well as the decontamination abilities were studied, respectively. It was preliminary identified as Acinetobacter sp. according to its physiological and biochemical characteristics and molecular identification results. In heterotrophic nitrification system, the ammonia nitrogen and total nitrogen removal rate of the bacterial strain TN-14 could reach 97.13% and 93.53% within 24 h. In nitrates denitrification system, the nitrate concentration could decline from 94.24 mg · L(-1) to 39.32 mg · L(-1) within 24 h, where the removal rate was 58.28% and the denitrification rate was 2.28 mg · (L · h)(-1); In nitrite denitrification systems, the initial concentration of nitrite could be declined from 97.78 mg · L(-1) to 21.30 mg x L(-1), with a nitrite nitrogen removal rate of 78.22%, and a denitrification rate of 2.55 mg · (L· h)(-1). Meanwhile, strain TN-14 had the capability of flocculant production, and the flocculating rate could reach 94.74% when its fermentation liquid was used to treat 0.4% kaolin suspension. Strain TN-14 could grow at an ammonia nitrogen concentration as high as 1200 mg · L(-1). In the aspect of actual piggery wastewater treatment by strain TN-14, the removal rate of COD, ammonia nitrogen, TN and TP cloud reached 85.30%, 65.72%, 64.86% and 79.41%, respectively. Strain TN-14 has a good application prospect in biological treatment of real high- ammonia wastewater. PMID:25693403

  12. The association between bedding material and the bacterial counts of Staphylococcus aureus, Streptococcus uberis and coliform bacteria on teat skin and in teat canals in lactating dairy cattle.

    PubMed

    Paduch, Jan-Hendrik; Mohr, Elmar; Krömker, Volker

    2013-05-01

    Several mastitis-causing pathogens are able to colonize the bovine teat canal. The objective of this study was to investigate the association between the treatment of sawdust bedding with a commercial alkaline conditioner and the bacterial counts on teat skin and in the teat canal. The study used a crossover design. Ten lactating Holstein cows that were free of udder infections and mastitis were included in the study. The animals were bedded on either untreated sawdust or sawdust that had been treated with a hydrated lime-based conditioner. Once a day, fresh bedding material was added. After 3 weeks, the bedding material was removed from the cubicles, fresh bedding material was provided, and the cows were rotated between the two bedding material groups. Teat skin and teat canals were sampled using the wet and dry swab technique after weeks 1, 2, 3, 4, 5 and 6. Staphylococcus aureus, Streptococcus uberis, Escherichia coli and other coliform bacteria were detected in the resulting agar plate cultures. The treatment of the bedding material was associated with the teat skin bacterial counts of Str. uberis, Esch. coli and other coliform bacteria. An association was also found between the bedding material and the teat canal bacterial counts of coliform bacteria other than Esch. coli. For Staph. aureus, no associations with the bedding material were found. In general, the addition of a hydrated lime-based conditioner to sawdust reduces the population sizes of environmental pathogens on teat skin and in teat canals. PMID:23445624

  13. Effect of 2 different premilking teat sanitation routines on reduction of bacterial counts on teat skin of cows on commercial dairy farms.

    PubMed

    Baumberger, C; Guarín, J F; Ruegg, P L

    2016-04-01

    Premilking teat sanitation reduces the load of bacteria on teat skin before milking and it is a fundamental practice used to ensure collection of high-quality milk. The objective of this study was to compare reduction in bacterial populations of teat skin after premilking preparation using either predipping with 0.5% iodine followed by drying (conventional; CONV) or using a semiautomated teat scrubber that uses chlorine dioxide (TS; FutureCow, Longwood, FL). Ten farms currently using a commercial teat scrubber system were enrolled. Cows (n=40 per farm) were assigned to CONV (n=198) or TS (n=196) premilking udder preparation. Teat skin swabs were collected before and after udder preparation and analyzed for total bacterial count (TBC), Streptococcus spp., Staphylococcus spp., and gram-negative bacteria (GNB). Reduction (RED) of each bacterial group was defined as the difference in the number of bacteria measured before and after udder preparation. Before udder preparation, Staphylococcus spp. (15,036 cfu/mL) and Streptococcus spp. (12,621 cfu/mL) were the most numerous microflora. Gram-negative bacteria were less numerous (1,538 cfu/mL). A significant treatment by farm interaction was identified for RED of all bacterial counts. Compared with teats prepared using TS, teats prepared using CONV preparation had greater RED of TBC on 3 farms, of Streptococcus spp. on 2 farms, and of Staphylococcus spp. on 1 farm. On all other farms, RED in TBC, Streptococcus spp., and Staphylococcus spp. did not differ based on teat preparation method. Use of TS resulted in greater RED of GNB of teats on 3 farms, but RED in GNB was greater for teats cleaned by CONV on 1 farm; for the other 6 farms, RED of GNB did not differ between methods. For all bacterial counts, an effect of chlorine dioxide concentration used in the teat scrubber was observed. Results from this study suggest both CONV and TS can effectively reduce bacterial counts, but farm conditions and management practices can

  14. Comparison of the TEMPO® System, Petrifilm® , and Cultural MPN Procedure for Enumeration of E. coli, Coliforms and Total Aerobic Plate Counts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Recent innovations in microbiological methods for analysis of food products have been in methods for detection of bacterial pathogens. Petrifilm dehydrated plates are the only significant addition to cultural procedures for indicator organisms in the last 20 years. An automated most...

  15. Comparison of bacterial counts in expressed breast milk following standard or strict infection control regimens in neonatal intensive care units: compliance of mothers does matter.

    PubMed

    Haiden, N; Pimpel, B; Assadian, O; Binder, C; Kreissl, A; Repa, A; Thanhäuser, M; Roberts, C D; Berger, A

    2016-03-01

    Bacterial counts in 1466 expressed breast milk (EBM) samples from women following one of two infection control regimens (standard vs strict) were investigated. Overall, 12% of samples yielded Gram-negative bacteria, with no significant differences between the standard [11.9% (94/788)] and strict [12.1% (82/678)] regimens (P = 0.92). Significantly more samples were contaminated when expressed at home (standard regimen home/hospital: 17.9% vs 6.1%; strict regimen home/hospital: 19.6% vs 3.4%; P < 0.001). Bacterial contamination of EBM was not associated with the regimen, but was associated with the location of breast milk expression. Attempts to improve personal hygiene during milk collection seem to be of limited value. Good hygiene of collection and storage equipment is likely to be the most important way to ensure the microbiological quality of EBM. PMID:26850928

  16. Bacterial counts on teat skin and in new sand, recycled sand, and recycled manure solids used as bedding in freestalls.

    PubMed

    Rowbotham, R F; Ruegg, P L

    2016-08-01

    10(3) cfu/swab) and greatest for cows bedded with RS (5.1×10(4) cfu/swab) or SBMS (1.6×10(5) cfu/swab). The numbers of all types of measured bacteria (total gram-negative, coliforms, Klebsiella spp., SSLO) on postpreparation teat swabs were reduced by up to 2.6 logs from numbers of bacteria on prepreparation swabs, verifying effective preparation procedures. Significant correlations between bacterial counts of bedding samples and teat skin swabs were observed for several types of bacteria. As compared with other bedding types, the least amount of gram-negative bacteria were recovered from NES and may indicate that cows on NES have a reduced risk of exposure to pathogens that are typically a cause of clinical mastitis. In contrast, exposure to large numbers of SSLO was consistent across all bedding types and may indicate that risk of subclinical mastitis typically associated with streptococci is not as influenced by bedding type; however, significantly greater numbers of SSLO were found in SBMS than in other bedding types. These findings indicate that use of different bedding types results in exposure to different distributions of mastitis pathogens that may alter the proportion of etiologies of clinical mastitis, although the incidence rate of clinical mastitis did not differ among bedding types. PMID:27265163

  17. Long-term exposure of bacterial and protozoan communities to TiO2 nanoparticles in an aerobic-sequencing batch reactor

    NASA Astrophysics Data System (ADS)

    Supha, Chitpisud; Boonto, Yuphada; Jindakaraked, Manee; Ananpattarachai, Jirapat; Kajitvichyanukul, Puangrat

    2015-06-01

    Titanium dioxide (TiO2) nanopowders at different concentrations (0-50 mg L-1) were injected into an aerobic-sequencing batch reactor (SBR) to investigate the effects of long-term exposure to nanoparticles on bacterial and protozoan communities. The detection of nanoparticles in the bioflocs was analyzed by scanning electron microscopy, transmission electron microscopy, and energy-dispersive x-ray spectroscopy. The SBR wastewater experiments were conducted under the influence of ultraviolet light with photocatalytic TiO2. The intrusion of TiO2 nanoparticles was found both on the surface and inside of the bioflocs. The change of microbial population in terms of mixed liquor-suspended solids and the sludge volume index was monitored. The TiO2 nanoparticles tentatively exerted an adverse effect on the microbial population, causing the reduction of microorganisms (both bacteria and protozoa) in the SBR. The respiration inhibition rate of the bacteria was increased, and the viability of the microbial population was reduced at the high concentration (50 mg L-1) of TiO2. The decreasing number of protozoa in the presence of TiO2 nanoparticles during 20 days of treatment with 0.5 and 1.0 mg L-1 TiO2 is clearly demonstrated. The measured chemical oxygen demand (COD) in the effluent tends to increase with a long-term operation. The increase of COD in the system suggests a decrease in the efficiency of the wastewater treatment plant. However, the SBR can effectively remove the TiO2 nanoparticles (up to 50 mg L-1) from the effluent.

  18. Enumeration of total aerobic bacteria and Escherichia coli in minced meat and on carcass surface samples with an automated most-probable-number method compared with colony count protocols.

    PubMed

    Paulsen, P; Schopf, E; Smulders, F J M

    2006-10-01

    An automated most-probable-number (MPN) system for the enumeration of total bacterial flora and Escherichia coli was compared with plate count agar and tryptone-bile-glucuronide (TBX) and ColiID (in-house method) agar methodology. The MPN partitioning of sample aliquots was done automatically on a disposable card containing 48 wells of 3 different volumes, i.e., 16 replicates per volume. Bacterial growth was detected by the formation of fluorescent 4-methylumbilliferone. After incubation, the number of fluorescent wells was read with a separate device, and the MPN was calculated automatically. A total of 180 naturally contaminated samples were tested (pig and cattle carcass surfaces, n = 63; frozen minced meat, n = 62; and refrigerated minced meat, n = 55). Plate count agar results and MPN were highly correlated (r = 0.99), with log MPN = -0.25 + 1.05 x log CFU (plate count agar) (n = 163; range, 2.2 to 7.5 log CFU/g or cm2). Only a few discrepancies were recorded. In two samples (1.1%), the differences were > or = 1.0 log; in three samples (1.7%), the differences were > or = 0.5 log. For E. coli, regression analysis was done for all three methods for 80 minced meat samples, which were above the limit of detection (1.0 log CFU/g): log MPN = 0.18 + 0.98 x log CFU (TBX), r = 0.96, and log MPN = -0.02 + 0.99 x log CFU (ColiID), r = 0.99 (range, 1.0 to 4.2 log CFU/g). Four discrepant results were recorded, with differences of > 0.5 but < 1.0 log unit. These results suggest that the automated MPN method described is a suitable and labor-saving alternative to colony count techniques for total bacterial flora and E. coli determination in minced meat or on carcass surfaces. PMID:17066934

  19. 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

  20. Effectiveness of Polyvalent Bacterial Lysate and Autovaccines Against Upper Respiratory Tract Bacterial Colonization by Potential Pathogens: A Randomized Study

    PubMed Central

    Zagólski, Olaf; Stręk, Paweł; Kasprowicz, Andrzej; Białecka, Anna

    2015-01-01

    Background Polyvalent bacterial lysate (PBL) is an oral immunostimulating vaccine consisting of bacterial standardized lysates obtained by lysis of different strains of bacteria. Autovaccines are individually prepared based on the results of smears obtained from the patient. Both types of vaccine can be used to treat an ongoing chronic infection. This study sought to determine which method is more effective against nasal colonization by potential respiratory tract pathogens. Material/Methods We enrolled 150 patients with aerobic Gram stain culture and count results indicating bacterial colonization of the nose and/or throat by potential pathogens. The participants were randomly assigned to each of the following groups: 1. administration of PBL, 2. administration of autovaccine, and 3. no intervention (controls). Results Reduction of the bacterial count in Streptococcus pneumoniae-colonized participants was significant after the autovaccine (p<0.001) and PBL (p<0.01). Reduction of the bacterial count of other β-hemolytic streptococcal strains after treatment with the autovaccine was significant (p<0.01) and was non-significant after PBL. In Haemophilus influenzae colonization, significant reduction in the bacterial count was noted in the PBL group (p<0.01). Methicillin-resistant Staphylococcus aureus colonization did not respond to either treatment. Conclusions The autovaccine is more effective than PBL for reducing bacterial count of Streptococcus pneumoniae and β-hemolytic streptococci, while PBL was more effective against Haemophilus influenzae colonization. PMID:26434686

  1. Development of a selective culture medium for bifidobacteria, Raffinose-Propionate Lithium Mupirocin (RP-MUP) and assessment of its usage with Petrifilm™ Aerobic Count plates.

    PubMed

    Miranda, Rodrigo Otávio; de Carvalho, Antonio Fernandes; Nero, Luís Augusto

    2014-05-01

    This study aimed to develop a selective culture media to enumerate bifidobacteria in fermented milk and to assess this medium when used with Petrifilm™ AC plates. For this purpose, Bifidobacterium spp., Lactobacillus spp. and Streptococcus thermophilus strains were tested to verify their fermentation patterns for different carbohydrates. All bifidobacteria strains were able to use raffinose. Based on these characteristic, a selective culture medium was proposed (Raffinose-Propionate Lithium Mupirocin, RP-MUP), used with Petrifilm™ AC plates, and was used to enumerate bifidobacteria in fermented milk. RP-MUP performance was assessed by comparing the results with this medium to reference protocols and culture media for bifidobacteria enumeration. RP-MUP, whether used or not with Petrifilm™ AC, presented similar performance to TOS-MUP (ISO 29981), with no significant differences between the mean bifidobacteria counts (p < 0.05) and with high correlation indices (r = 0.99, p < 0.05). As an advantage, reliable results were obtained after just 48 h of incubation when RP-MUP was used with Petrifilm™ AC, instead of the 72 h described in the ISO 29981 protocol. PMID:24387858

  2. Preliminary stochastic model for managing Vibrio parahaemolyticus and total viable bacterial counts in a Pacific oyster (Crassostrea gigas) supply chain.

    PubMed

    Fernandez-Piquer, Judith; Bowman, John P; Ross, Tom; Estrada-Flores, Silvia; Tamplin, Mark L

    2013-07-01

    Vibrio parahaemolyticus can accumulate and grow in oysters stored without refrigeration, representing a potential food safety risk. High temperatures during oyster storage can lead to an increase in total viable bacteria counts, decreasing product shelf life. Therefore, a predictive tool that allows the estimation of both V. parahaemolyticus populations and total viable bacteria counts in parallel is needed. A stochastic model was developed to quantitatively assess the populations of V. parahaemolyticus and total viable bacteria in Pacific oysters for six different supply chain scenarios. The stochastic model encompassed operations from oyster farms through consumers and was built using risk analysis software. Probabilistic distributions and predictions for the percentage of Pacific oysters containing V. parahaemolyticus and high levels of viable bacteria at the point of consumption were generated for each simulated scenario. This tool can provide valuable information about V. parahaemolyticus exposure and potential control measures and can help oyster companies and regulatory agencies evaluate the impact of product quality and safety during cold chain management. If coupled with suitable monitoring systems, such models could enable preemptive action to be taken to counteract unfavorable supply chain conditions. PMID:23834791

  3. Development of Microelectrode Arrays Using Electroless Plating for CMOS-Based Direct Counting of Bacterial and HeLa Cells.

    PubMed

    Niitsu, Kiichi; Ota, Shoko; Gamo, Kohei; Kondo, Hiroki; Hori, Masaru; Nakazato, Kazuo

    2015-10-01

    The development of two new types of high-density, electroless plated microelectrode arrays for CMOS-based high-sensitivity direct bacteria and HeLa cell counting are presented. For emerging high-sensitivity direct pathogen counting, two technical challenges must be addressed. One is the formation of a bacteria-sized microelectrode, and the other is the development of a high-sensitivity and high-speed amperometry circuit. The requirement for microelectrode formation is that the gold microelectrodes are required to be as small as the target cell. By improving a self-aligned electroless plating technique, the dimensions of the microelectrodes on a CMOS sensor chip in this work were successfully reduced to 1.2 μm × 2.05 μm. This is 1/20th of the smallest size reported in the literature. Since a bacteria-sized microelectrode has a severe limitation on the current flow, the amperometry circuit has to have a high sensitivity and high speed with low noise. In this work, a current buffer was inserted to mitigate the potential fluctuation. Three test chips were fabricated using a 0.6- μm CMOS process: two with 1.2 μm × 2.05 μm (1024 × 1024 and 4 × 4) sensor arrays and one with 6- μm square (16 × 16) sensor arrays; and the microelectrodes were formed on them using electroless plating. The uniformity among the 1024 × 1024 electrodes arranged with a pitch of 3.6 μm × 4.45 μm was optically verified. For improving sensitivity, the trenches on each microelectrode were developed and verified optically and electrochemically for the first time. Higher sensitivity can be achieved by introducing a trench structure than by using a conventional microelectrode formed by contact photolithography. Cyclic voltammetry (CV) measurements obtained using the 1.2 μm × 2.05 μm 4 × 4 and 6- μm square 16 × 16 sensor array with electroless-plated microelectrodes successfully demonstrated direct counting of the bacteria-sized microbeads and HeLa cells. PMID:26561481

  4. Leukocyte-subset counts in idiopathic parkinsonism provide clues to a pathogenic pathway involving small intestinal bacterial overgrowth. A surveillance study

    PubMed Central

    2012-01-01

    Background Following Helicobacter pylori eradication in idiopathic parkinsonism (IP), hypokinesia improved but flexor-rigidity increased. Small intestinal bacterial-overgrowth (SIBO) is a candidate driver of the rigidity: hydrogen-breath-test-positivity is common in IP and case histories suggest that Helicobacter keeps SIBO at bay. Methods In a surveillance study, we explore relationships of IP-facets to peripheral immune/inflammatory-activation, in light of presence/absence of Helicobacter infection (urea-breath- and/or stool-antigen-test: positivity confirmed by gastric-biopsy) and hydrogen-breath-test status for SIBO (positivity: >20 ppm increment, 2 consecutive 15-min readings, within 2h of 25G lactulose). We question whether any relationships found between facets and blood leukocyte subset counts stand in patients free from anti-parkinsonian drugs, and are robust enough to defy fluctuations in performance consequent on short t½ therapy. Results Of 51 IP-probands, 36 had current or past Helicobacter infection on entry, 25 having undergone successful eradication (median 3.4 years before). Thirty-four were hydrogen-breath-test-positive initially, 42 at sometime (343 tests) during surveillance (2.8 years). Hydrogen-breath-test-positivity was associated inversely with Helicobacter-positivity (OR 0.20 (95% CI 0.04, 0.99), p<0.05). In 38 patients (untreated (17) or on stable long-t½ IP-medication), the higher the natural-killer count, the shorter stride, slower gait and greater flexor-rigidity (by mean 49 (14, 85) mm, 54 (3, 104) mm.s-1, 89 (2, 177) Nm.10-3, per 100 cells.μl-1 increment, p=0.007, 0.04 & 0.04 respectively, adjusted for patient characteristics). T-helper count was inversely associated with flexor-rigidity before (p=0.01) and after adjustment for natural-killer count (-36(-63, -10) Nm.10-3 per 100 cells.μl-1, p=0.007). Neutrophil count was inversely associated with tremor (visual analogue scale, p=0.01). Effect-sizes were independent of IP

  5. Impact of Bifidobacterium animalis subsp. lactis BB-12 and, Lactobacillus acidophilus LA-5-containing yoghurt, on fecal bacterial counts of healthy adults.

    PubMed

    Savard, Patricia; Lamarche, Benoît; Paradis, Marie-Eve; Thiboutot, Hélène; Laurin, Émilie; Roy, Denis

    2011-09-01

    This randomized, placebo-controlled, double blind, parallel dose-response study investigated the impact of 4-week commercial yoghurt consumption supplemented with Bifidobacterium animalis subsp. lactis (BB-12) and Lactobacillus acidophilus (LA-5) on fecal bacterial counts of healthy adults. Fifty-eight volunteers were randomly assigned to three different groups: 1. placebo (no probiotic, no starter and no green tea extract); 2. Yoptimal (10(9)cfu/100g of BB-12 and LA-5 and 40mg of green tea extract) and 3. Yoptimal-10 (10(10)cfu/100g of BB-12, 10(9)cfu/100g of LA-5 and 40mg of green tea extract). These yoghurt products also contained Lactobacillus delbrueckii subsp. bulgaricus (10(7)cfu/100g) and Streptococcus thermophilus (10(10)cfu/100g). The quantitative PCR (qPCR) results showed that there were significant increases (P=0.02) in bifidobacteria counts with the Yoptimal treatment as compared to baseline. The fecal numbers of B. animalis subsp. lactis and LA-5 significantly increased in the two probiotic treatments compared to the placebo treatment. Viable counts of fecal lactobacilli were significantly higher (P=0.05) and those of enterococci were significantly lower (P=0.04) after the intervention when compared to placebo. No significant difference was observed between treatments in volunteers' weight, waist girth, blood pressure, fasting plasma triglyceride and HDL-C concentrations, as well as cholesterol/HDL-cholesterol ratio. However, a significant increase in plasma cholesterol levels was observed in the placebo group (P=0.0018) but the levels remained stable in the two probiotic yoghurt groups. These results show that probiotic strains supplemented in the form of yoghurt remain active during gut transit and are associated with an increase in beneficial bacteria and a reduction in potentially pathogenic bacteria. This trial was registered at clinicaltrials.gov as NCT00730626. PMID:21296446

  6. In Vitro Activities of Doripenem and Six Comparator Drugs against 423 Aerobic and Anaerobic Bacterial Isolates from Infected Diabetic Foot Wounds▿

    PubMed Central

    Goldstein, Ellie J. C.; Citron, Diane M.; Merriam, C. Vreni; Warren, Yumi A.; Tyrrell, Kerin L.; Fernandez, Helen T.

    2008-01-01

    Against 182 anaerobe and 241 aerobe strains obtained from diabetic foot infections, doripenem was the most active carbapenem against Pseudomonas aeruginosa (MIC90, 2 μg/ml), more active than imipenem against Proteus mirabilis, and ertapenem was more active against Escherichia coli and Klebsiella spp. The MIC50 and MIC90 values were ≤0.125 μg/ml for methicillin-sensitive Staphylococcus aureus and all streptococci and 0.25/1 for Bacteroides fragilis. PMID:18070958

  7. Aerobic bacterial microflora of Broad-snouted caiman (Caiman latirostris) oral cavity and cloaca, originating from parque Zoológico Arruda Câmara, Paraíba, Brazil.

    PubMed

    Silva, J S A; Mota, R A; Pinheiro Júnior, J W; Almeida, M C S; Silva, D R; Ferreira, D R A; Azevedo, J C N

    2009-01-01

    The objective of this study was to isolate and identify the aerobic bacterial microflora from the oral cavity mucosa and cloaca's samples, collected from Broad-snouted caiman (Caiman latirostris), born and bred in captivity at Parque Zoológico Arruda Câmara, João Pessoa, Paraíba, Brazil. The most common bacteria were Staphylococcus sp. (14.74%), Corynebacterium sp. (13.68%), Escherichia coli (13.68%) and Shigella sp.(11.58%), and the less common were Citrobacter sp. (1.05%), Klebsiella pneumoniae (1.05%) and Salmonella sp. (1.05%).This emphasizes the importance of these microorganisms' participation in infectious processes (sepsis) and injuries caused by crocodilians. PMID:24031343

  8. Bacterial Wound Culture

    MedlinePlus

    ... Home Visit Global Sites Search Help? Bacterial Wound Culture Share this page: Was this page helpful? Also known as: Aerobic Wound Culture; Anaerobic Wound Culture Formal name: Culture, wound Related ...

  9. Biodiversity of aerobic endospore-forming bacterial species occurring in Yanyanku and Ikpiru, fermented seeds of Hibiscus sabdariffa used to produce food condiments in Benin.

    PubMed

    Agbobatinkpo, Pélagie B; Thorsen, Line; Nielsen, Dennis S; Azokpota, Paulin; Akissoe, Noèl; Hounhouigan, Joseph D; Jakobsen, Mogens

    2013-05-15

    Yanyanku and Ikpiru made by the fermentation of Malcavene bean (Hibiscus sabdariffa) are used as functional additives for Parkia biglobosa seed fermentations in Benin. A total of 355 aerobic endospore-forming bacteria (AEFB) isolated from Yanyanku and Ikpiru produced in northern and southern Benin were identified using phenotypic and genotypic methods, including GTG5-PCR, M13-PCR, 16S rRNA, gyrA and gyrB gene sequencing. Generally, the same 5-6 species of the genus Bacillus predominated: Bacillus subtilis (17-41% of isolates), Bacillus cereus (8-39%), Bacillus amyloliquefaciens (9-22%), Bacillus licheniformis (3-26%), Bacillus safensis (8-19%) and Bacillus altitudinis (0-19%). Bacillus aryabhattai, Bacillus flexus, and Bacillus circulans (0-2%), and species of the genera Lysinibacillus (0-14%), Paenibacillus (0-13%), Brevibacillus (0-4%), and Aneurinibacillus (0-3%) occurred sporadically. The diarrheal toxin encoding genes cytK-1, cytK-2, hblA, hblC, and hblD were present in 0%, 91% 15%, 34% and 35% of B. cereus isolates, respectively. 9% of them harbored the emetic toxin genetic determinant, cesB. This study is the first to identify the AEFB of Yanyanku and Ikpiru to species level and perform a safety evaluation based on toxin gene detections. We further suggest, that the gyrA gene can be used for differentiating the closely related species Bacillus pumilus and B. safensis. PMID:23571124

  10. Water-quality parameters and total aerobic bacterial and Vibrionaceae loads in Eastern oysters (Crassostrea virginica) from oyster-gardening sites.

    PubMed

    Fay, Johnna P; Richards, Gary P; Ozbay, Gulnihal

    2012-05-01

    Oyster gardening is a practice designed to restore habitat for marine life and to improve water quality. This study determined physical and chemical water-quality parameters at two oyster gardening sites in the Delaware Inland Bays and compared them with total aerobic bacteria and Vibrionaceae concentrations in Eastern oysters (Crassostrea virginica). One site was located at the end of a man-made canal, whereas the other was located in an open bay. Measured water parameters included temperature, dissolved oxygen (DO), salinity, pH, total nitrogen, nitrate, nitrite, total phosphorus, and total suspended solids. The highest Vibrionaceae levels, as determined by the colony overlay procedure for peptidases, were at the canal site in September (3.5 × 10(5) g(-1)) and at the bay site in August (1.9 × 10(5) g(-1)). Vibrionaceae levels were significantly greater during the duration of the study at the canal site (P = 0.01). This study provides the first baseline levels for total Vibrionaceae in the Delaware Inland Bays. Minimum DO readings at the bay and canal sites were 3.0 and 2.3 mg l(-1), respectively, far less than the state-targeted minimum threshold of 5.0 mg l(-1). Total phosphorus levels exceeded recommendations of ≤0.1 mg l(-1) at the bay and canal sites for all monthly samplings, with mean monthly highs at both sites ≥0.68 mg l(-1) in August. Nitrogen occasionally exceeded the recommended level of 1.0 mg l(-1) at both sites. Overall, waters were highly degraded from high phosphates, nitrogen, and total suspended solids as well as low DO. PMID:22183874

  11. Analysis of bacterial diversity during the fermentation of inyu, a high-temperature fermented soy sauce, using nested PCR-denaturing gradient gel electrophoresis and the plate count method.

    PubMed

    Wei, Chia-Li; Chao, Shiou-Huei; Tsai, Wen-Bin; Lee, Pei-Shan; Tsau, Nai-Hung; Chen, Jhih-Shan; Lai, Wen-Lin; Tu, James Ching-Yueh; Tsai, Ying-Chieh

    2013-04-01

    The diversity of bacteria associated with the fermentation of inyu, also known as black soy sauce, was studied through the nested PCR-denaturing gradient gel electrophoresis (DGGE) of samples collected from the fermentation stages of the inyu production process. The DGGE profiles targeted the bacterial 16S rDNA and revealed the presence of Citrobacter farmeri, Enterobacter cloacae, Enterobacter hormaechei, Enterococcus faecium, Klebsiella pneumoniae, Pantoea agglomerans, Salmonella enterica, Serratia marcescens, Staphylococcus sciuri and Weissella confusa. The bacterial compositions of 4 fermented samples were further elucidated using the plate count method. The bacteria isolated from the koji-making stage exhibited the highest diversity; Brachybacterium rhamnosum, E. hormaechei, K. pneumoniae, Kurthia gibsonii, Pantoea dispersa, Staphylococcus gallinarum, Staphylococcus kloosii and S. sciuri were identified. Koji collected during the preincubation stage presented the largest cell counts, and E. hormaechei, K. pneumoniae, E. cloacae and Enterobacter pulveris were identified. In brine samples aged for 7 and 31 days, the majority of the bacteria isolated belonged to 4 Bacillus species, but 4 Staphylococcus species and Delftia tsuruhatensis were also detected. This study demonstrates the benefits of using a combined approach to obtain a more complete picture of microbial populations and provides useful information for the control or development of bacterial flora during inyu fermentation. PMID:23200659

  12. Cell counting.

    PubMed

    Phelan, M C; Lawler, G

    2001-05-01

    This unit presents protocols for counting cells using either a hemacytometer or electronically using a Coulter counter. Cell counting with a hemacytometer permits effective discrimination of live from dead cells using trypan blue exclusion. In addition, the procedure is less subject to errors arising from cell clumping or size heterogeneity. Counting cells is more quickly and easily performed using an electronic counter, but live-dead discrimination is unreliable. Cell populations containing large numbers of dead cells and/or cell clumps are difficult to count accurately. In addition, electronic counting requires resetting of the instrument for cell populations of different sizes; heterogeneous populations can give rise to inaccurate counts, and resting and activated cells may require counting at separate settings. In general, electronic cell counting is best performed on fresh peripheral blood cells. PMID:18770655

  13. Potential of a nisin-containing bacterial cellulose film to inhibit Listeria monocytogenes on processed meats.

    PubMed

    Nguyen, V T; Gidley, M J; Dykes, G A

    2008-05-01

    A bacterially produced cellulose film containing nisin was developed and used in a proof-of-concept study to control Listeria monocytogenes and total aerobic bacteria on the surface of vacuum-packaged frankfurters. Bacterial cellulose pellicles were produced by Gluconacetobacter xylinus K3 in Corn Steep Liquor-Mannitol Medium and were subsequently purified before nisin was incorporated into them. Investigations into the effect of nisin concentrations and contact times on incorporation of nisin into cellulose films showed that the lowest nisin concentration and shortest time needed for production of an effective antimicrobial cellulose film were 625IUml(-1) and 6h, respectively. The active cellulose films produced under these conditions did not, however, significantly reduce L. monocytogenes populations on frankfurters (P>0.05) during refrigerated storage for 14 days as compared to the controls. Films produced using a higher concentration of nisin (2500IUml(-1)) with the same exposure time (6h) resulted in a significant (P<0.05) decrease in L. monocytogenes counts on frankfurters of approximately 2logCFUg(-1) after 14 days of storage as compared to the control. Both the above-mentioned films showed a similar effectiveness in reducing total aerobic bacterial populations as measured by total aerobic plate counts on frankfurters. For both films, total aerobic bacterial levels were significantly (P>0.05) reduced by approximately 3.3logCFUg(-1) after 14 days of storage as compared to control samples. Bacterial cellulose films were demonstrated in this study to have potential applicability as antimicrobial packaging films or inserts for processed meat products. PMID:18355672

  14. 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;…

  15. Chthonomonas calidirosea gen. nov., sp. nov., an aerobic, pigmented, thermophilic micro-organism of a novel bacterial class, Chthonomonadetes classis nov., of the newly described phylum Armatimonadetes originally designated candidate division OP10.

    PubMed

    Lee, Kevin C-Y; Dunfield, Peter F; Morgan, Xochitl C; Crowe, Michelle A; Houghton, Karen M; Vyssotski, Mikhail; Ryan, Jason L J; Lagutin, Kirill; McDonald, Ian R; Stott, Matthew B

    2011-10-01

    An aerobic, saccharolytic, obligately thermophilic, motile, non-spore-forming bacterium, strain T49(T), was isolated from geothermally heated soil at Hell's Gate, Tikitere, New Zealand. On the basis of 16S rRNA gene sequence similarity, T49(T) is the first representative of a new class in the newly described phylum Armatimonadetes, formerly known as candidate division OP10. Cells of strain T49(T) stained Gram-negative and were catalase-positive and oxidase-negative. Cells possessed a highly corrugated outer membrane. The major fatty acids were 16 : 0, i17 : 0 and ai17 : 0. The G+C content of the genomic DNA was 54.6 mol%. Strain T49(T) grew at 50-73 °C with an optimum temperature of 68 °C, and at pH 4.7-5.8 with an optimum growth pH of 5.3. A growth rate of 0.012 h(-1) was observed under optimal temperature and pH conditions. The primary respiratory quinone was MK-8. Optimal growth was achieved in the absence of NaCl, although growth was observed at NaCl concentrations as high as 2 % (w/v). Strain T49(T) was able to utilize mono- and disaccharides such as cellobiose, lactose, mannose and glucose, as well as branched or amorphous polysaccharides such as starch, CM-cellulose, xylan and glycogen, but not highly linear polysaccharides such as crystalline cellulose or cotton. On the basis of its phylogenetic position and phenotypic characteristics, we propose that strain T49(T) represents a novel bacterial genus and species within the new class Chthonomonadetes classis nov. of the phylum Armatimonadetes. The type strain of Chthonomonas calidirosea gen. nov., sp. nov. is T49(T) ( = DSM 23976(T) = ICMP 18418(T)). PMID:21097641

  16. Record keeping, genetic selection, educational experience and farm management effects on average milk yield per cow, milk fat percentage, bacterial score and bulk tank somatic cell count of dairy farms in the Central region of Thailand.

    PubMed

    Rhone, J A; Koonawootrittriron, S; Elzo, M A

    2008-12-01

    A study was conducted to estimate the record keeping, genetic selection, educational, and farm management effects on average milk yield per cow (AYC), milk fat percentage, bacterial score, and bulk tank somatic cell count (BTSCC) of dairy farms in the central region of Thailand. Farms were located in the provinces of Saraburi and Nakhon Ratchisima and were members of the Muaklek dairy cooperative. Records from individual animals were unavailable. Thus, farm records of milk yield, milk fat percentage, bacterial score, and BTCCC were collected from July 1, 2003 through June 30, 2006. Additional record keeping, genetic selection, education, and farm management information was collected through a questionnaire in May of 2006. Data from the Muaklek dairy cooperative and the questionnaire were then merged by a farm identification number. A single trait mixed model was used to analyze AYC, milk fat percentage, and BTSCC, while a log linear model was used to analyze bacterial score. Results showed that farms that kept records on individual animals had higher (P < 0.05) milk fat percentages and lower bacterial scores than farms that did not. Farms that used genetic information (EBV) and phenotypes when selecting sires were higher (P < 0.05) for milk fat percentage than farms that used only phenotypes and personal opinion. Farms milking cows with a single unit milking machine and by hand, had higher (P < 0.05) bacterial scores and BTSCC than farms using only a single or multi unit machine. Overall farms that kept individual animal records, used EBV when selecting sires, used a single method for collecting milk, and used family labor achieved higher performance from their herds than farms that did not. PMID:18975127

  17. Sexual dimorphism in primate aerobic capacity: a phylogenetic test.

    PubMed

    Lindenfors, Patrik; Revell, L J; Nunn, C L

    2010-06-01

    Male intrasexual competition should favour increased male physical prowess. This should in turn result in greater aerobic capacity in males than in females (i.e. sexual dimorphism) and a correlation between sexual dimorphism in aerobic capacity and the strength of sexual selection among species. However, physiological scaling laws predict that aerobic capacity should be lower per unit body mass in larger than in smaller animals, potentially reducing or reversing the sex difference and its association with measures of sexual selection. We used measures of haematocrit and red blood cell (RBC) counts from 45 species of primates to test four predictions related to sexual selection and body mass: (i) on average, males should have higher aerobic capacity than females, (ii) aerobic capacity should be higher in adult than juvenile males, (iii) aerobic capacity should increase with increasing sexual selection, but also that (iv) measures of aerobic capacity should co-vary negatively with body mass. For the first two predictions, we used a phylogenetic paired t-test developed for this study. We found support for predictions (i) and (ii). For prediction (iii), however, we found a negative correlation between the degree of sexual selection and aerobic capacity, which was opposite to our prediction. Prediction (iv) was generally supported. We also investigated whether substrate use, basal metabolic rate and agility influenced physiological measures of oxygen transport, but we found only weak evidence for a correlation between RBC count and agility. PMID:20406346

  18. Multiplicity Counting

    SciTech Connect

    Geist, William H.

    2015-12-01

    This set of slides begins by giving background and a review of neutron counting; three attributes of a verification item are discussed: 240Pueff mass; α, the ratio of (α,n) neutrons to spontaneous fission neutrons; and leakage multiplication. It then takes up neutron detector systems – theory & concepts (coincidence counting, moderation, die-away time); detector systems – some important details (deadtime, corrections); introduction to multiplicity counting; multiplicity electronics and example distributions; singles, doubles, and triples from measured multiplicity distributions; and the point model: multiplicity mathematics.

  19. Examination of the Aerobic Microflora of Swine Feces and Stored Swine Manure.

    PubMed

    Whitehead, Terence R; Cotta, Michael A

    2016-03-01

    Understanding antibiotic resistance in agricultural ecosystems is critical for determining the effects of subtherapeutic and therapeutic uses of antibiotics for domestic animals. This study was conducted to ascertain the relative levels of antibiotic resistance in the aerobic bacterial population to tetracycline, tylosin, and erythromycin. Swine feces and manure samples were plated onto various agar media with and without antibiotics and incubated at 37°C. Colonies were counted daily. Randomly selected colonies were isolated and characterized by 16S rRNA sequence analyses and additional antibiotic resistance and biochemical analyses. Colonies were recovered at levels of 10 to 10 CFU mL for swine slurry and 10 to 10 CFU g swine feces, approximately 100-fold lower than numbers obtained under anaerobic conditions. Addition of antibiotics to the media resulted in counts that were 60 to 80% of those in control media without added antibiotics. Polymerase chain reaction analyses for antibiotic resistance genes demonstrated the presence of a number of different resistance genes from the isolates. The recoverable aerobic microflora of swine feces and manure contain high percentages of antibiotic-resistant bacteria, which include both known and novel genera and species, and a variety of antibiotic resistance genes. Further analyses of these and additional isolates should provide additional information on these organisms as potential reservoirs of antibiotic resistance genes in these ecosystems. PMID:27065407

  20. Basic vaginal pH, bacterial vaginosis and aerobic vaginitis: prevalence in early pregnancy and risk of spontaneous preterm delivery, a prospective study in a low socioeconomic and multiethnic South American population

    PubMed Central

    2014-01-01

    Background Bacterial vaginosis (BV) increases the risk of spontaneous preterm deliveries (PD) in developed countries. Its prevalence varies with ethnicity, socioeconomic conditions and gestational age. Aerobic vaginitis (AV) has also been implicated with spontaneous PD. The present study aimed to estimate the prevalence of asymptomatic BV, the accuracy of vaginal pH level to predict BV and to estimate the risk of spontaneous PD <34 and <37 weeks’ gestation of BV and AV. Methods Women attending prenatal public services in Rio de Janeiro were screened to select asymptomatic pregnant women, < 20 weeks’ gestation, with no indication for elective PD and without risk factors of spontaneous PD. Vaginal smears of women with vaginal pH > = 4.5 were collected to determine the Nugent score; a sample of those smears was also classified according to a modified Donders’ score. Primary outcomes were spontaneous PD < 34 and <37 weeks’ gestation and abortion. Results Prevalence of asymptomatic BV was estimated in 28.1% (n = 1699); 42.4% of the smears were collected before 14 weeks’ gestation. After an 8-week follow up, nearly 40% of the initially BV positive women became BV negative. The prevalence of BV among white and black women was 28.1% (95% CI: 24.6%-32.0%) and 32.5% (95% CI: 28.2%-37.2%), respectively. The sensitivity of vaginal pH= > 4.5 and = > 5.0 to predict BV status was 100% and 82%, correspondingly; the 5.0 cutoff value doubled the specificity, from 41% to 84%. The incidence of < 37 weeks’ spontaneous PDs among BV pregnant women with a pH= > 4.5 was 3.8%. The RR of spontaneous PD < 34 and <37 weeks among BV women with pH > =4.5, as compared with those with intermediate state, were 1.24 and 1.86, respectively (Fisher’s exact test, p value = 1; 0.52, respectively, both ns). No spontaneous case of PD or abortion was associated with severe or moderate AV. Conclusions A high prevalence of asymptomatic BV was

  1. Aerobic biodegradation of trichloroethene without auxiliary substrates.

    PubMed

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

    2014-08-01

    Trichloroethene (TCE) represents a priority pollutant and is among the most frequently detected contaminants in groundwater. The current bioremediation measures have certain drawbacks like e.g. the need for auxiliary substrates. Here, the aerobic biodegradation of TCE as the sole growth substrate is demonstrated. This new process of metabolic TCE degradation was first detected in groundwater samples. TCE degradation was stable in an enriched mixed bacterial culture in mineral salts medium for over five years and repeated transfers of the culture resulting in a 10(10) times dilution of the original groundwater. Aerobic TCE degradation resulted in stoichiometric chloride formation. Stable carbon isotope fractionation was observed providing a reliable analytical tool to assess this new biodegradation process at field sites. The results suggest that aerobic biodegradation of TCE without auxiliary substrate could be considered as an option for natural attenuation or engineered bioremediation of contaminated sites. PMID:24793109

  2. Effect of temperature-controlled fermentation on physico-chemical properties and lactic acid bacterial count of durian (Durio zibethinus Murr.) pulp.

    PubMed

    Wasnin, Ramdiah M; Karim, Muhammad Shahrim Abdul; Ghazali, Hasanah Mohd

    2014-11-01

    Effects of controlled-temperature fermentation on several physico-chemical properties, lactic acid bacteria (LAB) counts and aroma of durian pulp were examined by storing fresh durian pulp was mixed with 2 % (w/w) salt and stored at 15 °C, 27 °C and 40 °C for 10 days. Storage at 15 °C did not affect the properties of the pulp much. However, at 27 °C and 40 °C, pH and total soluble solids decreased up to 60 % and 52 %, respectively, with greater losses at 27 °C. Titratable acidity, which increased at 27 °C, was due to lactic and acetic acids formation. Loss of sucrose and increases in glucose were greater at 27 °C. LAB population increased up to Day 3 of storage, and then decreased slightly. Principal component analysis based on aroma examination using a zNose(TM) showed better retention of aroma profile at 27 °C. Overall, durian fermented at 27 °C was more acceptable than the one prepared at 40 °C, and it is ready to be consumed between Day 4 and 6. PMID:26396291

  3. Evaluation of the limulus amoebocyte lysate test in conjunction with a gram negative bacterial plate count for detecting irradiation of chicken

    NASA Astrophysics Data System (ADS)

    Scotter, Susan L.; Wood, Roger; McWeeny, David J.

    A study to evaluate the potential of the Limulus amoebocyte lysate (LAL) test in conjuction with a Gram negative bacteria (GNB) plate count for detecting the irradiation of chicken is described. Preliminary studies demonstrated that chickens irradiated at an absorbed dose of 2.5 kGy could be differentiated from unirradiated birds by measuring levels of endotoxin and of numbers of GNB on chicken skin. Irradiated birds were found to have endotoxin levels similar to those found in unirradiated birds but significantly lower numbers of GNB. In a limited study the test was found to be applicable to birds from different processors. The effect of temperature abuse on the microbiological profile, and thus the efficacy of the test, was also investigated. After temperature abuse, the irradiated birds were identifiable at worst up to 3 days after irradiation treatment at the 2.5 kGy level and at best some 13 days after irradiation. Temperature abuse at 15°C resulted in rapid recovery of surviving micro-organisms which made differentiation of irradiated and unirradiated birds using this test unreliable. The microbiological quality of the bird prior to irradiation treatment also affected the test as large numbers of GNB present on the bird prior to irradiation treatment resulted in larger numbers of survivors. In addition, monitoring the developing flora after irradiation treatment and during subsequent chilled storage also aided differentiation of irradiated and unirradiated birds. Large numbers of yeasts and Gram positive cocci were isolated from irradiated carcasses whereas Gram negative oxidative rods were the predominant spoilage flora on unirradiated birds.

  4. Bacterial contamination in Saeng-go-gi, a ready-to-eat fresh raw beef dish sold in restaurants in South Korea.

    PubMed

    Park, Myoung Su; Moon, Jin San; Todd, Ewen C D; Bahk, Gyung Jin

    2015-03-01

    This study investigated the bacterial contamination levels in ready-to-eat fresh raw beef, Saeng-go-gi in Korean, sold in restaurants. A total of 462 samples were analyzed by performing an aerobic bacterial plate count, a coliform count, and an Escherichia coli O157:H7 count. Aerobic bacterial plate counts of fresh raw beef obtained from Seoul, Cheonan, Daegu, Gunsan, and Gwangju retail store restaurants were 6.46, 6.89, 6.39, 6.58, and 6.67 log CFU/g, respectively, and coliforms were 4.05, 4.97, 4.76, 3.62, and 3.32 log CFU/g, respectively. Among the 462 assessed samples, suspected E. coli O157:H7 colonies were found in 32, 24, 20, 22, and 16 samples obtained from Seoul, Cheonan, Daegu, Gunsan, and Gwangju, respectively. The identity of these isolated colonies was further assessed by using a latex agglutination kit. The agglutination assay data showed that the isolates were not E. coli O157:H7. The data from this study could be used to design better food handling practices for reducing foodborne illnesses linked to fresh raw beef consumption. PMID:25719891

  5. Counting Penguins.

    ERIC Educational Resources Information Center

    Perry, Mike; Kader, Gary

    1998-01-01

    Presents an activity on the simplification of penguin counting by employing the basic ideas and principles of sampling to teach students to understand and recognize its role in statistical claims. Emphasizes estimation, data analysis and interpretation, and central limit theorem. Includes a list of items for classroom discussion. (ASK)

  6. RBC count

    MedlinePlus

    ... Drugs that can increase the RBC count include: Gentamicin Methyldopa Lower-than-normal numbers of RBCs may be due to: Anemia Bleeding Bone marrow failure (for example, from radiation, toxins, or tumor) Deficiency of a hormone called erythropoietin (caused by ...

  7. Counting Populations

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    Scientists use sampling to get an estimate of things they cannot easily count. A population is made up of all the organisms of one species living together in one place at the same time. All of the people living together in one town are considered a population. All of the grasshoppers living in a field are a population. Scientists keep track of the…

  8. Petrifilm plates for enumeration of bacteria counts in goat milk

    Technology Transfer Automated Retrieval System (TEKTRAN)

    PetrifilmTM Aerobic Count (AC) and Coliform Count (CC) plates were validated against standard methods for enumeration of coliforms, total bacteria, and psychrotrophic bacteria in raw (n = 39) and pasteurized goat milk (n = 17) samples. All microbiological data were transformed into log form and sta...

  9. Teaching Aerobic Lifestyles: New Perspectives.

    ERIC Educational Resources Information Center

    Goodrick, G. Ken; Iammarino, Nicholas K.

    1982-01-01

    New approaches to teaching aerobic life-styles in secondary schools are suggested, focusing on three components: (1) the psychological benefits of aerobic activity; (2) alternative aerobic programs at nonschool locations; and (3) the development of an aerobics curriculum to help maintain an active life-style after graduation. (JN)

  10. Aerobic Conditioning Class.

    ERIC Educational Resources Information Center

    Johnson, Neil R.

    1980-01-01

    An aerobic exercise class that focuses on the conditioning of the cardiovascular and muscular systems is presented. Students complete data cards on heart rate, pulse, and exercises to be completed during the forty minute course. (CJ)

  11. [Research advances in aerobic denitrifiers].

    PubMed

    Wang, Wei; Cai, Zu-cong; Zhong, Wen-hui; Wang, Guo-xiang

    2007-11-01

    This paper reviewed the varieties and characteristics of aerobic denitrifiers, their action mechanisms, and the factors affecting aerobic denitrification. Aerobic denitrifiers mainly include Pseudomonas, Alcaligenes, Paracoccus and Bacillus, which are either aerobic or facultative aerobic, and heterotrophic. They can denitrify under aerobic conditions, with the main product being N2O. They can also convert NH4+ -N to gas product. The nitrate reductase which catalyzes the denitrification is periplasmic nitrate reductase rather than membrane-bound nitrate reductase. Dissolved oxygen concentration and C/N ratio are the main factors affecting aerobic denitrification. The main methods for screening aerobic denitrifiers, such as intermittent aeration and selected culture, were also introduced. The research advances in the application of aerobic denitrifiers in aquaculture, waste water processing, and bio-degradation of organic pollutants, as well as the contributions of aerobic denitrifiers to soil nitrogen emission were summarized. PMID:18260473

  12. Reticulocyte Count Test

    MedlinePlus

    ... Reticulocyte Count Related tests: Red Blood Cell Count ; Hemoglobin ; Hematocrit ; Complete Blood Count ; Blood Smear ; Erythropoietin ; Vitamin ... on a complete blood count (CBC) , RBC count , hemoglobin or hematocrit , to help determine the cause To ...

  13. White Blood Cell Count

    MedlinePlus

    ... Home Visit Global Sites Search Help? White Blood Cell Count Share this page: Was this page helpful? Also ... Leukocyte Count; White Count Formal name: White Blood Cell Count Related tests: Complete Blood Count , Blood Smear , White ...

  14. [Bacterial vaginosis].

    PubMed

    Romero Herrero, Daniel; Andreu Domingo, Antonia

    2016-07-01

    Bacterial vaginosis (BV) is the main cause of vaginal dysbacteriosis in the women during the reproductive age. It is an entity in which many studies have focused for years and which is still open for discussion topics. This is due to the diversity of microorganisms that cause it and therefore, its difficult treatment. Bacterial vaginosis is probably the result of vaginal colonization by complex bacterial communities, many of them non-cultivable and with interdependent metabolism where anaerobic populations most likely play an important role in its pathogenesis. The main symptoms are an increase of vaginal discharge and the unpleasant smell of it. It can lead to serious consequences for women, such as an increased risk of contracting sexually transmitted infections including human immunodeficiency virus and upper genital tract and pregnancy complications. Gram stain is the gold standard for microbiological diagnosis of BV, but can also be diagnosed using the Amsel clinical criteria. It should not be considered a sexually transmitted disease but it is highly related to sex. Recurrence is the main problem of medical treatment. Apart from BV, there are other dysbacteriosis less characterized like aerobic vaginitis of which further studies are coming slowly but are achieving more attention and consensus among specialists. PMID:27474242

  15. Interaction of Cadmium With the Aerobic Bacterium Pseudomonas Mendocina

    NASA Astrophysics Data System (ADS)

    Schramm, P. J.; Haack, E. A.; Maurice, P. A.

    2006-05-01

    The fate of toxic metals in the environment can be heavily influenced by interaction with bacteria in the vadose zone. This research focuses on the interactions of cadmium with the strict aerobe Pseudomonas mendocina. P. mendocina is a gram-negative bacterium that has shown potential in the bioremediation of recalcitrant organic compounds. Cadmium is a common environmental contaminant of wide-spread ecological consequence. In batch experiments P. mendocina shows typical bacterial growth curves, with an initial lag phase followed by an exponential phase and a stationary to death phase; concomitant with growth was an increase in pH from initial values of 7 to final values at 96 hours of 8.8. Cd both delays the onset of the exponential phase and decreases the maximum population size, as quantified by optical density and microscopic cell counts (DAPI). The total amount of Cd removed from solution increases over time, as does the amount of Cd removed from solution normalized per bacterial cell. Images obtained with transmission electron microscopy (TEM) showed the production of a cadmium, phosphorus, and iron containing precipitate that was similar in form and composition to precipitates formed abiotically at elevated pH. However, by late stationary phase, the precipitate had been re-dissolved, perhaps by biotic processes in order to obtain Fe. Stressed conditions are suggested by TEM images showing the formation of pili, or nanowires, when 20ppm Cd was present and a marked decrease in exopolysaccharide and biofilm material in comparison to control cells (no cadmium added).

  16. Method of detecting and counting bacteria

    NASA Technical Reports Server (NTRS)

    Picciolo, G. L.; Chappelle, E. W. (Inventor)

    1976-01-01

    An improved method is provided for determining bacterial levels, especially in samples of aqueous physiological fluids. The method depends on the quantitative determination of bacterial adenosine triphosphate (ATP) in the presence of nonbacterial ATP. The bacterial ATP is released by cell rupture and is measured by an enzymatic bioluminescent assay. A concentration technique is included to make the method more sensitive. It is particularly useful where the fluid to be measured contains an unknown or low bacteria count.

  17. HETEROTROPHIC PLATE COUNT (HPC) METHODOLOGY IN THE UNITED STATES

    EPA Science Inventory

    ABSTRACT

    In the United States (U.S.), the history of bacterial plate counting methods used for water can be traced largely through Standard Methods for the Examination of Water and Wastewater (Standard Methods). The bacterial count method has evolved from the original St...

  18. 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)

  19. Comparative study of seasonal variation in bacterial flora concomitant with farm raised fingerlings of Cyprinus carpio at tarai region of Uttarakhand.

    PubMed

    Bisht, A; Singh, U P; Pandey, N N

    2014-03-01

    The bacterial infection is an important economic and limiting factor in intensive fish production. The present study focuses on investigation of the bacterial population associated with farmed common carp fingerlings, its environment and limnological quality of pond, during winter and summer season. It was found that the bacterial count in the pond sediment (6.40 cfu x 10(4)) was about 10 times higher in comparison of pond water (6.93 cfu x 10(3)). Further, the intestinal bacterial count was about 100 times higher (6.67 cfu x 10(5)) during winter and 1000 times higher (2.33 cfu x 10(6)) during summer season in comparison to the surfacial skin of fish during winter and summer (3.39 and 8.87 cfu x 10(3)), respectively. The isolated bacteria were both Gram negative and Gram positive, mostly aerobic rods. Furthermore, the temperature showed a significant relation with the bacterial counts of pond water. In the summer season, higher bacterial counts (8.72 cfu x 10(3)) were recorded as compared to winter (5.13 cfu x 10(3)). The dominant bacteria isolated from the sample of pond water, pond sediment and fish were identified as Aeromonas hydrophila, Pseudomonas fluorescens, Pseudomonas sp., Flavobacter sp., Bacillus sp., Micrococcus sp., Corynebacterium sp. Moreover, the bacterial density was dependent on C:N values, and the optimum range of C: N ratio was found between 16-23, for the carp culture ponds. Among the isolated bacterial flora, the presence of strains which were well known for their probiotic properties suggested an autochthonous source for use in aquaculture. Further, analysis of various physico-chemical parameters of pond water revealed that they were within the suitable range for the freshwater fish culture throughout farming phase. PMID:24665763

  20. 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)

  1. Managing for Improved Aerobic Stability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aerobic deterioration or spoilage of silage is the result of aerobic microorganisms metabolizing components of the silage using oxygen. In the almost 40 years over which these silage conferences have been held, we have come to recognize the typical pattern of aerobic microbial development by which s...

  2. Kinetic Behavior of Salmonella on Low NaNO2 Sausages during Aerobic and Vacuum Storage

    PubMed Central

    Ha, Jimyeong; Gwak, Eunji; Oh, Mi-Hwa; Park, Beomyoung; Lee, Jeeyeon; Kim, Sejeong; Lee, Heeyoung; Lee, Soomin; Yoon, Yohan; Choi, Kyoung-Hee

    2016-01-01

    This study evaluated the growth kinetics of Salmonella spp. in processed meat products formulated with low sodium nitrite (NaNO2). A 5-strain mixture of Salmonella spp. was inoculated on 25-g samples of sausages formulated with sodium chloride (NaCl) (1.0%, 1.25%, and 1.5%) and NaNO2 (0 and 10 ppm) followed by aerobic or vacuum storage at 10℃ and 15℃ for up to 816 h or 408 h, respectively. The bacterial cell counts were enumerated on xylose lysine deoxycholate agar, and the modified Gompertz model was fitted to the Salmonella cell counts to calculate the kinetic parameters as a function of NaCl concentration on the growth rate (GR; Log CFU/g/h) and lag phase duration (LPD; h). A linear equation was then fitted to the parameters to evaluate the effect of NaCl concentration on the kinetic parameters. The GR values of Salmonella on sausages were higher (p<0.05) with 10 ppm NaNO2 concentration than with 0 ppm NaNO2. The GR values of Salmonella decreased (p<0.05) as NaCl concentration increased, especially at 10℃. This result indicates that 10 ppm NaNO2 may increase Salmonella growth at low NaCl concentrations, and that NaCl plays an important role in inhibiting Salmonella growth in sausages with low NaNO2. PMID:27194936

  3. Kinetic Behavior of Salmonella on Low NaNO2 Sausages during Aerobic and Vacuum Storage.

    PubMed

    Ha, Jimyeong; Gwak, Eunji; Oh, Mi-Hwa; Park, Beomyoung; Lee, Jeeyeon; Kim, Sejeong; Lee, Heeyoung; Lee, Soomin; Yoon, Yohan; Choi, Kyoung-Hee

    2016-01-01

    This study evaluated the growth kinetics of Salmonella spp. in processed meat products formulated with low sodium nitrite (NaNO2). A 5-strain mixture of Salmonella spp. was inoculated on 25-g samples of sausages formulated with sodium chloride (NaCl) (1.0%, 1.25%, and 1.5%) and NaNO2 (0 and 10 ppm) followed by aerobic or vacuum storage at 10℃ and 15℃ for up to 816 h or 408 h, respectively. The bacterial cell counts were enumerated on xylose lysine deoxycholate agar, and the modified Gompertz model was fitted to the Salmonella cell counts to calculate the kinetic parameters as a function of NaCl concentration on the growth rate (GR; Log CFU/g/h) and lag phase duration (LPD; h). A linear equation was then fitted to the parameters to evaluate the effect of NaCl concentration on the kinetic parameters. The GR values of Salmonella on sausages were higher (p<0.05) with 10 ppm NaNO2 concentration than with 0 ppm NaNO2. The GR values of Salmonella decreased (p<0.05) as NaCl concentration increased, especially at 10℃. This result indicates that 10 ppm NaNO2 may increase Salmonella growth at low NaCl concentrations, and that NaCl plays an important role in inhibiting Salmonella growth in sausages with low NaNO2. PMID:27194936

  4. Biology of Moderately Halophilic Aerobic Bacteria

    PubMed Central

    Ventosa, Antonio; Nieto, Joaquín J.; Oren, Aharon

    1998-01-01

    The moderately halophilic heterotrophic aerobic bacteria form a diverse group of microorganisms. The property of halophilism is widespread within the bacterial domain. Bacterial halophiles are abundant in environments such as salt lakes, saline soils, and salted food products. Most species keep their intracellular ionic concentrations at low levels while synthesizing or accumulating organic solutes to provide osmotic equilibrium of the cytoplasm with the surrounding medium. Complex mechanisms of adjustment of the intracellular environments and the properties of the cytoplasmic membrane enable rapid adaptation to changes in the salt concentration of the environment. Approaches to the study of genetic processes have recently been developed for several moderate halophiles, opening the way toward an understanding of haloadaptation at the molecular level. The new information obtained is also expected to contribute to the development of novel biotechnological uses for these organisms. PMID:9618450

  5. Eosinophil count - absolute

    MedlinePlus

    Eosinophils; Absolute eosinophil count ... the white blood cell count to give the absolute eosinophil count. ... than 500 cells per microliter (cells/mcL). Normal value ranges may vary slightly among different laboratories. Talk ...

  6. Aerobic landfill bioreactor

    DOEpatents

    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.

  7. Aerobic landfill bioreactor

    DOEpatents

    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.

  8. First Comprehensive Evaluation of the M.I.C. Evaluator Device Compared to Etest and CLSI Broth Microdilution for MIC Testing of Aerobic Gram-Positive and Gram-Negative Bacterial Species

    PubMed Central

    Turnbull, L.; Brosnikoff, C.; Cloke, J.

    2012-01-01

    The M.I.C. Evaluator strip (Thermo Fisher Scientific, Basingstoke, United Kingdom) uses a methodology similar to that of Etest. In this first assessment of the M.I.C. Evaluator device, 409 strains of aerobic Gram-positive bacteria (staphylococci, streptococci, and enterococci) and 325 strains of Enterobacteriaceae, Pseudomonas species, and Acinetobacter species were tested by M.I.C. Evaluator strip, Etest, and broth microdilution as a reference standard. The Gram-positive bacteria included staphylococci (methicillin-resistant Staphylococcus aureus, methicillin-susceptible S. aureus, and coagulase-negative staphylococci), Streptococcus pneumoniae, beta-hemolytic streptococci and viridians group strains, vancomycin-resistant enterococci, and other enterococci. The Gram-negative bacteria included 250 strains of 60 Enterobacteriaceae species plus 50 Pseudomonas and 25 Acinetobacter species. A total of 14 antimicrobial agents (depending on the species) were included. The same methodology and reading format were used for M.I.C. Evaluator strips and Etest. Broth microdilution methodology was performed according to CLSI document M07-A8. For the clinical strains, >95% of results were plus or minus one doubling dilution for all species. There were fewer than 5% minor errors, fewer than 3% major errors, and fewer than 1% very major errors. M.I.C. Evaluator strips and Etest often reported higher MICs than the reference broth microdilution method. The M.I.C. Evaluator strips provided results comparable to those of the predicate Etest device and are of value for the accurate testing of MICs for these important pathogens. PMID:22238441

  9. Aerobic Fitness and School Children.

    ERIC Educational Resources Information Center

    Hinkle, J. Scott

    1997-01-01

    Provides school counselors with information on aerobic exercise (specifically running) and the psychological, behavioral, and physical benefits children obtained by participating in fitness programs. Recommends collaboration between school counselors and physical education teachers and gives a preliminary discussion of aerobic running and its…

  10. Aerobic Fitness and School Children.

    ERIC Educational Resources Information Center

    Hinkle, J. Scott

    1992-01-01

    Provides school counselors with information regarding aerobic exercise (specifically running), and the psychological, behavioral, and physical benefits children obtain by participating in fitness programs. Presents methods of collaboration between school counselors and physical education teachers. Offers preliminary discussion of aerobic running…

  11. 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…

  12. Changes in bacterial flora of Japanese cabbage during growth and potential source of flora.

    PubMed

    Izumi, Hidemi; Sera, Kaori

    2011-04-01

    Bacterial flora of cabbage were identified and enumerated during various stages of growth, and the potential sources of contamination in the field were determined. Bacterial counts increased from below the level of detection (2.4 log CFU/g) on seeds to 2.5 to 5.7 log CFU/g on seedlings. After transplanting, the counts of mesophilic aerobic bacteria on leaves decreased and then increased to 5.7 log CFU/g on outer leaves, 5.0 log CFU/g on middle leaves, and 3.0 log CFU/g on inner leaves at the harvesting stage. Counts of coliforms were below the level of detection during the growing period of the leaves. Bacteria isolated from cabbage seeds, seedlings, and leaves were soilborne organisms such as Bacillus, Curtobacterium, and Delftia and phytopathogenic organisms such as Pseudomonas, Pantoea, and Stenotrophomonas. These bacteria were found frequently in seeding machines, potting soil mix, soil, agricultural water, pesticide solutions mixed with the agricultural water, liquid fertilizers, and chemical fertilizers. Contamination from these environmental sites occurred throughout the cabbage growing period rather than only at the harvesting stage. These results indicate that use of clean water for irrigation and for mixing with pesticides and amendments from seeding to the harvesting stage is an important part of a good agricultural practices program for cabbage in Japan. PMID:21477482

  13. Aerobic and anaerobic microbiology of infections after trauma in children.

    PubMed Central

    Brook, I

    1998-01-01

    OBJECTIVE: To review the recovery of aerobic and anaerobic bacteria from infections after trauma in children over a 20 year period. METHODS: Only specimens that were studied for both aerobic and anaerobic bacteria were included in the analysis. They were collected from seven separate centres in which the microbiology laboratories only accepted specimens that were properly collected without contamination and were submitted in appropriate transport media. Anaerobes and aerobic bacteria were cultured and identified using standard techniques. Clinical records were reviewed to identify post-trauma patients. RESULTS: From 1974 to 1994, 175 specimens obtained from 166 children with trauma showed bacterial growth. The trauma included blunt trauma (71), lacerations (48), bites (42), and open fractures (5). Anaerobic bacteria only were isolated in 38 specimens (22%), aerobic bacteria only in 51 (29%), and mixed aerobic-anaerobic flora in 86 (49%); 363 anaerobic (2.1/specimen) and 158 aerobic or facultative isolates (0.9/specimen) were recovered. The predominant anaerobic bacteria included Peptostreptococcus spp (115 isolates), Prevotella spp (68), Fusobacterium spp (52), B fragilis group (42), and Clostridium spp (21). The predominant aerobic bacteria included Staph aureus (51), E coli (13), Ps aeruginosa (12), Str pyogenes (11) and Klebsiella pneumoniae (9). Principal infections were: abscesses (52), bacteraemia (3), pulmonary infections (30, including aspiration pneumonia, tracheostomy associated pneumonia, empyema, and ventilator associated pneumonia), wounds (36, including cellulitis, post-traumatic wounds, decubitus ulcers, myositis, gastrostomy and tracheostomy site wounds, and fasciitis), bites (42, including 23 animal and 19 human), peritonitis (4), osteomyelitis (5), and sinusitis (3). Staph aureus and Str pyogenes were isolated at all sites. However, organisms of the oropharyngeal flora predominated in infections that originated from head and neck wounds and

  14. Small-Scale Vertical Distribution of Bacterial Biomass and Diversity in Biological Soil Crusts from Arid Lands in the Colorado Plateau

    USGS Publications Warehouse

    Garcia-Pichel, F.; Johnson, S.L.; Youngkin, D.; Belnap, J.

    2003-01-01

    We characterized, at millimeter resolution, bacterial biomass, diversity, and vertical stratification of biological soil crusts in arid lands from the Colorado Plateau. Microscopic counts, extractable DNA, and plate counts of viable aerobic copiotrophs (VAC) revealed that the top centimeter of crusted soils contained atypically large bacterial populations, tenfold larger than those in uncrusted, deeper soils. The plate counts were not always consistent with more direct estimates of microbial biomass. Bacterial populations peaked at the immediate subsurface (1-2 mm) in light-appearing, young crusts, and at the surface (0-1 mm) in well-developed, dark crusts, which corresponds to the location of cyanobacterial populations. Bacterial abundance decreased with depth below these horizons. Spatially resolved DGGE fingerprints of Bacterial 16S rRNA genes demonstrated the presence of highly diverse natural communities, but we could detect neither trends with depth in bacterial richness or diversity, nor a difference in diversity indices between crust types. Fingerprints, however, revealed the presence of marked stratification in the structure of the microbial communities, probably a result of vertical gradients in physicochemical parameters. Sequencing and phylogenetic analyses indicated that most of the naturally occurring bacteria are novel types, with low sequence similarity (83-93%) to those available in public databases. DGGE analyses of the VAC populations indicated communities of lower diversity, with most types having sequences more than 94% similar to those in public databases. Our study indicates that soil crusts represent small-scale mantles of fertility in arid ecosystems, harboring vertically structured, little-known bacterial populations that are not well represented by standard cultivation methods.

  15. Efficiency of ciprofloxacin for bacterial control, post-thaw quality, and in vivo fertility of buffalo spermatozoa.

    PubMed

    Akhter, S; Ansari, M S; Rakha, B A; Andrabi, S M H; Qadeer, S; Iqbal, R; Ullah, N

    2013-09-01

    Ciprofloxacin (CP) was evaluated for bacterial control, post-thaw quality, and fertility of buffalo semen. Pseudomonas aeruginosa, Escherichia coli, Proteus sp., Corynebacterium sp., Micrococcus sp., and Staphylococcus sp. were isolated from buffalo semen. Pseudomonas aeruginosa, Corynebacterium sp., and Micrococcus sp. were resistant to streptomycin, whereas P. aeruginosa and Proteus sp. were resistant to penicillin. All bacteria were susceptible to CP. In vitro dose toxicity was assessed in sodium citrate buffer containing 0, 200 to 2000 μg/mL of CP. CP up to 1000 μg/mL was found nontoxic to motility and viability of buffalo sperm. For post-thaw quality, buffalo semen was frozen in Tris-citric acid extender containing streptomycin-penicillin (SP; 1000 μg/mL-1000 IU/mL) or CP 600 μg/mL and was assessed for total aerobic bacterial count (post-thaw), motility, plasma membrane integrity, viability at 0, 2, and 4 hours post-thaw. At 4 hours post-thaw, plasma membrane integrity (%) was higher (P < 0.05) in extender containing CP than SP. Total aerobic bacterial count was 0.00 in extender containing CP compared with 0.07 × 10(4) cfu/mL with SP. To assess the in vivo fertility rate, semen (two bulls) frozen in Tris-citric acid extender containing SP or CP was used to inseminate, and 400 inseminations (200/group) were recorded. Higher (P ≤ 0.05) fertility rate was recorded with CP (55%) compared with SP (41%). In conclusion, use of CP in extender was efficient to control the bacterial contamination without compromising the post-thaw quality and fertility of cryopreserved water buffalo bull semen. PMID:23746693

  16. Microbial Dynamics during Aerobic Exposure of Corn Silage Stored under Oxygen Barrier or Polyethylene Films▿

    PubMed Central

    Dolci, Paola; Tabacco, Ernesto; Cocolin, Luca; Borreani, Giorgio

    2011-01-01

    The aims of this study were to compare the effects of sealing forage corn with a new oxygen barrier film with those obtained by using a conventional polyethylene film. This comparison was made during both ensilage and subsequent exposure of silage to air and included chemical, microbiological, and molecular (DNA and RNA) assessments. The forage was inoculated with a mixture of Lactobacillus buchneri, Lactobacillus plantarum, and Enterococcus faecium and ensiled in polyethylene (PE) and oxygen barrier (OB) plastic bags. The oxygen permeability of the PE and OB films was 1,480 and 70 cm3 m−2 per 24 h at 23°C, respectively. The silages were sampled after 110 days of ensilage and after 2, 5, 7, 9, and 14 days of air exposure and analyzed for fermentation characteristics, conventional microbial enumeration, and bacterial and fungal community fingerprinting via PCR-denaturing gradient gel electrophoresis (DGGE) and reverse transcription (RT)-PCR-DGGE. The yeast counts in the PE and OB silages were 3.12 and 1.17 log10 CFU g−1, respectively, with corresponding aerobic stabilities of 65 and 152 h. Acetobacter pasteurianus was present at both the DNA and RNA levels in the PE silage samples after 2 days of air exposure, whereas it was found only after 7 days in the OB silages. RT-PCR-DGGE revealed the activity of Aspergillus fumigatus in the PE samples from the day 7 of air exposure, whereas it appeared only after 14 days in the OB silages. It has been shown that the use of an oxygen barrier film can ensure a longer shelf life of silage after aerobic exposure. PMID:21821764

  17. Microbial dynamics during aerobic exposure of corn silage stored under oxygen barrier or polyethylene films.

    PubMed

    Dolci, Paola; Tabacco, Ernesto; Cocolin, Luca; Borreani, Giorgio

    2011-11-01

    The aims of this study were to compare the effects of sealing forage corn with a new oxygen barrier film with those obtained by using a conventional polyethylene film. This comparison was made during both ensilage and subsequent exposure of silage to air and included chemical, microbiological, and molecular (DNA and RNA) assessments. The forage was inoculated with a mixture of Lactobacillus buchneri, Lactobacillus plantarum, and Enterococcus faecium and ensiled in polyethylene (PE) and oxygen barrier (OB) plastic bags. The oxygen permeability of the PE and OB films was 1,480 and 70 cm³ m⁻² per 24 h at 23°C, respectively. The silages were sampled after 110 days of ensilage and after 2, 5, 7, 9, and 14 days of air exposure and analyzed for fermentation characteristics, conventional microbial enumeration, and bacterial and fungal community fingerprinting via PCR-denaturing gradient gel electrophoresis (DGGE) and reverse transcription (RT)-PCR-DGGE. The yeast counts in the PE and OB silages were 3.12 and 1.17 log₁₀ CFU g⁻¹, respectively, with corresponding aerobic stabilities of 65 and 152 h. Acetobacter pasteurianus was present at both the DNA and RNA levels in the PE silage samples after 2 days of air exposure, whereas it was found only after 7 days in the OB silages. RT-PCR-DGGE revealed the activity of Aspergillus fumigatus in the PE samples from the day 7 of air exposure, whereas it appeared only after 14 days in the OB silages. It has been shown that the use of an oxygen barrier film can ensure a longer shelf life of silage after aerobic exposure. PMID:21821764

  18. Effect of chlorine, sodium chloride, trisodium phosphate, and ultraviolet radiation on the reduction of Yersinia enterocolitica and mesophilic aerobic bacteria from eggshell surface.

    PubMed

    Favier, G L; Escudero, M E; de Guzman, A M

    2001-10-01

    Eggshell sanitizing practices are necessary to improve microbiological safety of fresh hen eggs and their products. In this work, the effects of 100 mg/liter free chlorine (chl), 3% sodium chloride (NaCl), 1, 5, and 12% trisodium phosphate (TSP) in wash solutions, and UVR (ultraviolet radiation; 4.573 microW/cm2) were studied at different times on uninoculated and Yersinia enterocolitica-inoculated eggs. On uninoculated eggs, the best results were obtained with 100 mg/liter chlorine and UV exposure for >25 min, with reductions of 1.28 and 1.60 log cycles, respectively, compared to the average bacterial count (4.55 log CFU/egg) on the control (untreated eggs). On Y. enterocolitica-inoculated eggs, highest reductions of the average bacterial count (7.35 log CFU/egg) were obtained with 5 and 12% TSP and 100 mg/liter chl. The decrease obtained with 12% TSP (3.74-log reduction) was significantly higher (P < 0.05) than those obtained with the remaining treatments. Y. enterocolitica was more resistant to UVR than the eggshell natural mesophilic aerobic microflora, except when low inoculum (4.39 log CFU/egg) was assayed. Changes in eggshell microstructure were measured by the blue lake staining method. The presence of Yersinia and Salmonella in eggshell natural flora was also investigated. PMID:11601717

  19. The Big Pumpkin Count.

    ERIC Educational Resources Information Center

    Coplestone-Loomis, Lenny

    1981-01-01

    Pumpkin seeds are counted after students convert pumpkins to jack-o-lanterns. Among the activities involved, pupils learn to count by 10s, make estimates, and to construct a visual representation of 1,000. (MP)

  20. Bistability and Bacterial Infections

    PubMed Central

    Malka, Roy; Shochat, Eliezer; Rom-Kedar, Vered

    2010-01-01

    Bacterial infections occur when the natural host defenses are overwhelmed by invading bacteria. The main component of the host defense is impaired when neutrophil count or function is too low, putting the host at great risk of developing an acute infection. In people with intact immune systems, neutrophil count increases during bacterial infection. However, there are two important clinical cases in which they remain constant: a) in patients with neutropenic-associated conditions, such as those undergoing chemotherapy at the nadir (the minimum clinically observable neutrophil level); b) in ex vivo examination of the patient's neutrophil bactericidal activity. Here we study bacterial population dynamics under fixed neutrophil levels by mathematical modelling. We show that under reasonable biological assumptions, there are only two possible scenarios: 1) Bacterial behavior is monostable: it always converges to a stable equilibrium of bacterial concentration which only depends, in a gradual manner, on the neutrophil level (and not on the initial bacterial level). We call such a behavior type I dynamics. 2) The bacterial dynamics is bistable for some range of neutrophil levels. We call such a behavior type II dynamics. In the bistable case (type II), one equilibrium corresponds to a healthy state whereas the other corresponds to a fulminant bacterial infection. We demonstrate that published data of in vitro Staphylococcus epidermidis bactericidal experiments are inconsistent with both the type I dynamics and the commonly used linear model and are consistent with type II dynamics. We argue that type II dynamics is a plausible mechanism for the development of a fulminant infection. PMID:20463954

  1. Fate of classical faecal bacterial markers and ampicillin-resistant bacteria in agricultural soils under Mediterranean climate after urban sludge amendment.

    PubMed

    Gondim-Porto, Clarissa; Platero, Leticia; Nadal, Ignacio; Navarro-García, Federico

    2016-09-15

    The use of sewage sludge or biosolids as agricultural amendments may pose environmental and human health risks related to pathogen or antibiotic-resistant microorganism transmission from soils to vegetables or to water through runoff. Since the survival of those microorganisms in amended soils has been poorly studied under Mediterranean climatic conditions, we followed the variation of soil fecal bacterial markers and ampicillin-resistant bacteria for two years with samplings every four months in a split block design with three replica in a crop soil where two different types of biosolids (aerobically or anaerobically digested) at three doses (low, 40; intermediate, 80; and high, 160Mg·ha(-1)) were applied. Low amounts of biosolids produced similar decay rates of coliform populations than in control soil (-0.19 and -0.27log10CFUs·g(-1)drysoilmonth(-1) versus -0.22) while in the case of intermediate and high doses were close to zero and their populations remained 24months later in the range of 4-5log10CFUs·g(-1)ds. Enterococci populations decayed at different rates when using aerobic than anaerobic biosolids although high doses had higher rates than control (-0.09 and -0.13log10CFUs·g(-1)dsmonth(-1) for aerobic and anaerobic, respectively, vs -0.07). At the end of the experiment, counts in high aerobic and low and intermediate anaerobic plots were 1 log10 higher than in control (4.21, 4.03, 4.2 and 3.11log10CFUs·g(-1) ds, respectively). Biosolid application increased the number of Clostridium spores in all plots at least 1 log10 with respect to control with a different dynamic of decay for low and intermediate doses of aerobic and anaerobic sludge. Ampicillin-resistant bacteria increased in amended soils 4months after amendment and remained at least 1 log10 higher 24months later, especially in aerobic and low and intermediate anaerobic plots due to small rates of decay (in the range of -0.001 to -0.008log10CFUs·g(-1)dsmonth(-1) vs -0.016 for control). Aerobic

  2. Bacterial quality and safety of packaged fresh leafy vegetables at the retail level in Finland.

    PubMed

    Nousiainen, L-L; Joutsen, S; Lunden, J; Hänninen, M-L; Fredriksson-Ahomaa, M

    2016-09-01

    Consumption of packaged fresh leafy vegetables, which are convenient ready-to-eat products, has increased during the last decade. The number of foodborne outbreaks associated with these products has concurrently increased. In our study, (1) label information, (2) O2/CO2 composition, (3) bacterial quality and (4) safety of 100 fresh leafy vegetables at the retail level were studied in Finland during 2013. Bacterial quality was studied using aerobic bacteria (AB) and coliform bacteria (CB) counts, and searching for the presence of Escherichia coli, Listeria and Yersinia. The safety was studied by the presence of Salmonella, ail-positive Yersinia, stx-positive E. coli (STEC) and Listeria monocytogenes using PCR and culturing. Important label information was unavailable on several packages originating from different companies. The packaging date was missing on all packages and the date of durability on 83% of the packages. Storage temperature was declared on 62% of the packages and 73% of the packages contained information about prewashing. The batch/lot number was missing on 29% of the packages. Very low oxygen (O2) (<1%) and elevated carbon dioxide (CO2) (2-22%) concentrations were measured in all packages labelled to contain a protective atmosphere. O2 and CO2 concentrations varied widely in the rest of the packages. AB and CB counts were high in the leafy vegetable samples varying between 6.2 and 10.6 and 4.2-8.3logcfu/g, respectively. In most of the samples, the AB and CB counts exceeded 10(8) and 10(6)cfu/g, respectively. A positive correlation was observed between the AB and CB counts. E. coli was isolated from 15% of the samples and Yersinia from 33%. L. monocytogenes was isolated from two samples and ail-positive Y. enterocolitica in one. Using PCR, STEC was detected in seven samples, and Salmonella and ail-positive Y. enterocolitica in two samples each. The AB and CB mean values of products originating from different companies varied widely. High AB and CB

  3. Counting Sheep in Basque

    ERIC Educational Resources Information Center

    Araujo, Frank P.

    1975-01-01

    Demonstrates the interplay of a cognitive system, the Basque numerative system, and a behavioral one, counting sheep. The significant features of the Basque numerative system are analyzed; then it is shown how use of these features facilitates the counting of sheep on open ranges by Basque sheep farmers in California. (Author/RM)

  4. The Makah Counting Workbook.

    ERIC Educational Resources Information Center

    Flinn, Arlington A., Jr.

    The first edition of the counting workbook centers around the numbers from 1 to 100 and focuses on number and set concepts. The workbook introduces the Makah spelling of each number and reinforces the spelling with exercises such as matching words to numbers, writing the words, counting symbols, and circling the correct number. Spaced throughout…

  5. Complexities of Counting.

    ERIC Educational Resources Information Center

    Stake, Bernadine Evans

    This document focuses on one child's skip counting methods. The pupil, a second grade student at Steuben School, in Kankakee, Illinois, was interviewed as she made several attempts at counting twenty-five poker chips on a circular piece of paper. The interview was part of a larger study of "Children's Conceptions of Number and Numeral," funded by…

  6. Inhibition of Salmonella Typhimurium by Cultures of Cecal Bacteria during Aerobic Incubation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two trials were conducted to examine the ability of cecal bacterial cultures from broilers to inhibit growth of Salmonella Typhimurium during aerobic incubation. Cecal broth media was inoculated with 10 µl of cecal contents from 6 week old broilers taken from 2 separate flocks. Cultures were incubat...

  7. Bacterial Diversity in a Nonsaline Alkaline Environment: Heterotrophic Aerobic Populations

    PubMed Central

    Tiago, Igor; Chung, Ana Paula; Veríssimo, António

    2004-01-01

    Heterotrophic populations were isolated and characterized from an alkaline groundwater environment generated by active serpentinization, which results in a Ca(OH)2-enriched, extremely diluted groundwater with pH 11.4. One hundred eighty-five strains were isolated in different media at different pH values during two sampling periods. To assess the degree of diversity present in the environment and to select representative strains for further characterization of the populations, we screened the isolates by using random amplified polymorphic DNA-PCR profiles and grouped them based on similarities determined by fatty acid methyl ester analysis. Phenotypic characterization, determinations of G+C content, phylogenetic analyses by direct sequencing of 16S rRNA genes, and determinations of pH tolerance were performed with the selected isolates. Although 38 different populations were identified and characterized, the vast majority of the isolates were gram positive with high G+C contents and were affiliated with three distinct groups, namely, strains closely related to the species Dietzia natrolimnae (32% of the isolates), to Frigoribacterium/Clavibacter lineages (29% of the isolates), and to the type strain of Microbacterium kitamiense (20% of the isolates). Other isolates were phylogenetically related to strains of the genera Agrococcus, Leifsonia, Kytococcus, Janibacter, Kocuria, Rothia, Nesterenkonia, Citrococcus, Micrococcus, Actinomyces, Rhodococcus, Bacillus, and Staphylococcus. Only five isolates were gram negative: one was related to the Sphingobacteria lineage and the other four were related to the α-Proteobacteria lineage. Despite the pH of the environment, the vast majority of the populations were alkali tolerant, and only two strains were able to grow at pH 11. PMID:15574939

  8. Bacterial population dynamics of aerobic and anaerobic dairy waste treatment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background and Aims: Modern high intensity dairy farms generate large amounts of waste (manure and urine) that is stored in lagoons until it is disposed of by land application on crop fields. This practice has resulted in nutrients leaching into ground and surface waters, poor air quality from volat...

  9. Antibacterial Action of Nitric Oxide-Releasing Chitosan Oligosaccharides against Pseudomonas aeruginosa under Aerobic and Anaerobic Conditions

    PubMed Central

    Reighard, Katelyn P.

    2015-01-01

    Chitosan oligosaccharides were modified with N-diazeniumdiolates to yield biocompatible nitric oxide (NO) donor scaffolds. The minimum bactericidal concentrations and MICs of the NO donors against Pseudomonas aeruginosa were compared under aerobic and anaerobic conditions. Differential antibacterial activities were primarily the result of NO scavenging by oxygen under aerobic environments and not changes in bacterial physiology. Bacterial killing was also tested against nonmucoid and mucoid biofilms and compared to that of tobramycin. Smaller NO payloads were required to eradicate P. aeruginosa biofilms under anaerobic versus aerobic conditions. Under oxygen-free environments, the NO treatment was 10-fold more effective at killing biofilms than tobramycin. These results demonstrate the potential utility of NO-releasing chitosan oligosaccharides under both aerobic and anaerobic environments. PMID:26239983

  10. Characterization of a marine origin aerobic nitrifying-denitrifying bacterium.

    PubMed

    Zheng, Hai-Yan; Liu, Ying; Gao, Xi-Yan; Ai, Guo-Min; Miao, Li-Li; Liu, Zhi-Pei

    2012-07-01

    The bacterial strain F6 was isolated from a biological aerated filter that is used for purifying recirculating water in a marine aquaculture system and was identified as Marinobacter sp. based on the analysis of its 16S rRNA gene sequence. Strain F6 showed efficient aerobic denitrifying ability. One hundred percent of nitrates and 73.10% of nitrites were removed, and the total nitrogen (TN) removal rates reached 50.08% and 33.03% under a high nitrate and nitrite concentration in the medium, respectively. N(2)O and (15)N(2), as revealed by GC-MS and GC-IRMS, were the products of aerobic denitrification. Factors affecting the growth and aerobic denitrifying performance of strain F6 were investigated. The results showed that the optimum aerobic denitrification conditions for strain F6 were the presence of sodium succinate as a carbon source, a C/N ratio of 15, salinity ranging from 32-35 g/L of NaCl, incubation temperature of 30°C, an initial pH of 7.5, and rotation speed of 150 rpm [dissolved oxygen (DO) 6.75 mg/L]. In addition, strain F6 was confirmed to be a heterotrophic nitrifier through its NO(2)(-) generation and 25.96% TN removal when NH(4)(+) was used as the sole N source. Therefore, strain F6, the first reported member of genus Marinobacter with aerobic heterotrophic nitrifying-denitrifying ability, is an excellent candidate for facilitating simultaneous nitrification and denitrification (SND) in industry and aquaculture wastewater. PMID:22578593

  11. 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)

  12. HETEROTROPHIC PLATE COUNT BACTERIA IN POTABLE WATER: MONITORING METHODS AND APPLICATION

    EPA Science Inventory

    The heterotrophic plate count (HPC), formerly known as the standard plate count, is a useful tool for enumerating bacteria in potable water. his chapter briefly reviews the development of the heterotrophic bacterial plate count for use in water quality measurements in the United ...

  13. Kibdelomycin Is a Bactericidal Broad-Spectrum Aerobic Antibacterial Agent

    PubMed Central

    Dayananth, Priya; Balibar, Carl J.; Garlisi, Charles G.; Lu, Jun; Kishii, Ryuta; Takei, Masaya; Fukuda, Yasumichi; Ha, Sookhee; Young, Katherine

    2015-01-01

    Bacterial resistance to antibiotics continues to grow and pose serious challenges, while the discovery rate for new antibiotics declines. Kibdelomycin is a recently discovered natural-product antibiotic that inhibits bacterial growth by inhibiting the bacterial DNA replication enzymes DNA gyrase and topoisomerase IV. It was reported to be a broad-spectrum aerobic Gram-positive agent with selective inhibition of the anaerobic bacterium Clostridium difficile. We have extended the profiling of kibdelomycin by using over 196 strains of Gram-positive and Gram-negative aerobic pathogens recovered from worldwide patient populations. We report the MIC50s, MIC90s, and bactericidal activities of kibdelomycin. We confirm the Gram-positive spectrum and report for the first time that kibdelomycin shows strong activity (MIC90, 0.125 μg/ml) against clinical strains of the Gram-negative nonfermenter Acinetobacter baumannii but only weak activity against Pseudomonas aeruginosa. We confirm that well-characterized resistant strains of Staphylococcus aureus and Streptococcus pneumoniae show no cross-resistance to kibdelomycin and quinolones and coumarin antibiotics. We also show that kibdelomycin is not subject to efflux in Pseudomonas, though it is in Escherichia coli, and it is generally affected by the outer membrane permeability entry barrier in the nonfermenters P. aeruginosa and A. baumannii, which may be addressable by structure-based chemical modification. PMID:25845866

  14. Comparison of fluorescence microscopy and solid-phase cytometry methods for counting bacteria in water

    USGS Publications Warehouse

    Lisle, John T.; Hamilton, Martin A.; Willse, Alan R.; McFeters, Gordon A.

    2004-01-01

    Total direct counts of bacterial abundance are central in assessing the biomass and bacteriological quality of water in ecological and industrial applications. Several factors have been identified that contribute to the variability in bacterial abundance counts when using fluorescent microscopy, the most significant of which is retaining an adequate number of cells per filter to ensure an acceptable level of statistical confidence in the resulting data. Previous studies that have assessed the components of total-direct-count methods that contribute to this variance have attempted to maintain a bacterial cell abundance value per filter of approximately 106 cells filter-1. In this study we have established the lower limit for the number of bacterial cells per filter at which the statistical reliability of the abundance estimate is no longer acceptable. Our results indicate that when the numbers of bacterial cells per filter were progressively reduced below 105, the microscopic methods increasingly overestimated the true bacterial abundance (range, 15.0 to 99.3%). The solid-phase cytometer only slightly overestimated the true bacterial abundances and was more consistent over the same range of bacterial abundances per filter (range, 8.9 to 12.5%). The solid-phase cytometer method for conducting total direct counts of bacteria was less biased and performed significantly better than any of the microscope methods. It was also found that microscopic count data from counting 5 fields on three separate filters were statistically equivalent to data from counting 20 fields on a single filter.

  15. "Aerobic" Writing: A Writing Practice Model.

    ERIC Educational Resources Information Center

    Crisp, Sally Chandler

    "Aerobic writing" is a writing center strategy designed to keep students in writing "shape." Like aerobic exercise, aerobic writing is sustained for a certain length of time and done on a regular basis at prescribed time intervals. The program requires students to write at least two times a week for approximately an hour each time. Students write,…

  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. Bacterial concentration and diversity in fresh tropical shrimps (Penaeus notialis) and the surrounding brackish waters and sediment.

    PubMed

    Dabadé, D Sylvain; Wolkers-Rooijackers, Judith C M; Azokpota, Paulin; Hounhouigan, D Joseph; Zwietering, Marcel H; Nout, M J Rob; den Besten, Heidy M W

    2016-02-01

    This study aimed at determining bacterial concentration and diversity in fresh tropical shrimps (Penaeus notialis) and their surrounding brackish waters and sediment. Freshly caught shrimp, water and sediment samples were collected in Lakes Nokoue and Aheme in Benin (West Africa) during two periods with different water salinity and temperature. We used complementary culture-dependent and culture-independent methods for microbiota analysis. During both sampling periods, total mesophilic aerobic counts in shrimp samples ranged between 4.4 and 5.9 log CFU/g and were significantly higher than in water or sediment samples. In contrast, bacterial diversity was higher in sediment or water than in shrimps. The dominant phyla were Firmicutes and Proteobacteria in shrimps, Firmicutes, Proteobacteria, and Actinobacteria in water, and Proteobacteria and Chloroflexi in sediment. At species level, distinct bacterial communities were associated with sediment, water and shrimps sampled at the same site the same day. The study suggests that the bacterial community of tropical brackish water shrimps cannot be predicted from the microbiota of their aquatic environment. Thus, monitoring of microbiological quality of aquatic environments might not reflect shrimp microbiological quality. PMID:26656527

  18. Sublattice counting and orbifolds

    NASA Astrophysics Data System (ADS)

    Hanany, Amihay; Orlando, Domenico; Reffert, Susanne

    2010-06-01

    Abelian orbifolds of mathbb{C}3 are known to be encoded by hexagonal brane tilings. To date it is not known how to count all such orbifolds. We fill this gap by employing number theoretic techniques from crystallography, and by making use of Polya's Enumeration Theorem. The results turn out to be beautifully encoded in terms of partition functions and Dirichlet series. The same methods apply to counting orbifolds of any toric non-compact Calabi-Yau singularity. As additional examples, we count the orbifolds of the conifold, of the L aba theories, and of mathbb{C}4.

  19. Inventory count strategies.

    PubMed

    Springer, W H

    1996-02-01

    An important principle of accounting is that asset inventory needs to be correctly valued to ensure that the financial statements of the institution are accurate. Errors is recording the value of ending inventory in one fiscal year result in errors to published financial statements for that year as well as the subsequent fiscal year. Therefore, it is important that accurate physical counts be periodically taken. It is equally important that any system being used to generate inventory valuation, reordering or management reports be based on consistently accurate on-hand balances. At the foundation of conducting an accurate physical count of an inventory is a comprehensive understanding of the process coupled with a written plan. This article presents a guideline of the physical count processes involved in a traditional double-count approach. PMID:10165241

  20. Calorie count - Alcoholic beverages

    MedlinePlus

    ... want to watch how much you drink. Cocktails mixed with soda, cream, or ice cream can have especially high calorie counts. If you find you are having trouble cutting back on alcohol , talk with your doctor. Here is a list ...

  1. Blood Count Tests

    MedlinePlus

    Your blood contains red blood cells (RBC), white blood cells (WBC), and platelets. Blood count tests measure the number and types of cells in your blood. This helps doctors check on your overall health. ...

  2. Blood Count Tests

    MedlinePlus

    ... white blood cells (WBC), and platelets. Blood count tests measure the number and types of cells in ... helps doctors check on your overall health. The tests can also help to diagnose diseases and conditions ...

  3. Counting Knights and Knaves

    ERIC Educational Resources Information Center

    Levin,Oscar; Roberts, Gerri M.

    2013-01-01

    To understand better some of the classic knights and knaves puzzles, we count them. Doing so reveals a surprising connection between puzzles and solutions, and highlights some beautiful combinatorial identities.

  4. The effectiveness of peppermint and thyme essential oil mist in reducing bacterial contamination in broiler houses.

    PubMed

    Witkowska, D; Sowinska, J

    2013-11-01

    The antimicrobial properties of essential oils have been demonstrated by various in vitro studies, whereas their effect on poultry farm hygiene has not been thoroughly investigated, in particular with reference to aerial treatment. The present study aims to assess the antibacterial effects of natural essential oils in broiler houses. Two experimental rooms were fogged with aqueous solutions of peppermint and thyme oils. The control room was sprayed with pure water. The experiment was conducted on broilers aged 1 to 42 d. The rooms were fogged every 3 d. One day after fogging, the total counts of mesophilic aerobic bacteria, Enterobacteriaceae, and mannitol-positive staphylococci were determined. Samples were collected from the air, litter, walls, and drinkers. The results of the study demonstrate that essential oil mist may improve hygiene standards in broiler farms. During broiler growth, the mean total counts of mesophilic bacteria in the rooms treated with essential oils were lower (P < 0.01 or P < 0.05) in comparison with the control. Enterobacteriaceae and staphylococci counts were also higher in the control group. A single exception was noted in a litter sample where the mean count of Enterobacteriaceae in the room fogged with peppermint oil was higher than in the control. Both oils reduced bacterial counts, but thyme oil was more effective in reducing coliform bacteria, whereas peppermint oil had a higher inhibitory effect on the proliferation of staphylococci. These promising results encourage further research to determine the optimal doses and the effects of essential oils and their combinations on the living conditions and health status of broiler chickens. PMID:24135585

  5. Bacterial Sialidase

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Data shows that elevated sialidase in bacterial vaginosis patients correlates to premature births in women. Bacterial sialidase also plays a significant role in the unusual colonization of Pseudomonas aeruginosa in cystic fibrosis patients. Crystals of Salmonella sialidase have been reproduced and are used for studying the inhibitor-enzyme complexes. These inhibitors may also be used to inhibit a trans-sialidase of Trypanosome cruzi, a very similar enzyme to bacterial sialidase, therefore preventing T. cruzi infection, the causitive agent of Chagas' disease. The Center for Macromolecular Crystallography suggests that inhibitors of bacterial sialidases can be used as prophylactic drugs to prevent bacterial infections in these critical cases.

  6. Maximal aerobic exercise following prolonged sleep deprivation.

    PubMed

    Goodman, J; Radomski, M; Hart, L; Plyley, M; Shephard, R J

    1989-12-01

    The effect of 60 h without sleep upon maximal oxygen intake was examined in 12 young women, using a cycle ergometer protocol. The arousal of the subjects was maintained by requiring the performance of a sequence of cognitive tasks throughout the experimental period. Well-defined oxygen intake plateaus were obtained both before and after sleep deprivation, and no change of maximal oxygen intake was observed immediately following sleep deprivation. The endurance time for exhausting exercise also remained unchanged, as did such markers of aerobic performance as peak exercise ventilation, peak heart rate, peak respiratory gas exchange ratio, and peak blood lactate. However, as in an earlier study of sleep deprivation with male subjects (in which a decrease of treadmill maximal oxygen intake was observed), the formula of Dill and Costill (4) indicated the development of a substantial (11.6%) increase of estimated plasma volume percentage with corresponding decreases in hematocrit and red cell count. Possible factors sustaining maximal oxygen intake under the conditions of the present experiment include (1) maintained arousal of the subjects with no decrease in peak exercise ventilation or the related respiratory work and (2) use of a cycle ergometer rather than a treadmill test with possible concurrent differences in the impact of hematocrit levels and plasma volume expansion upon peak cardiac output and thus oxygen delivery to the working muscles. PMID:2628360

  7. Somatic cells count in cow's bulk tank milk.

    PubMed

    Olechnowicz, Jan; Jaśkowski, Jedrzej M

    2012-06-01

    The objective of this study was therefore to present factors affecting somatic cell counts in bovine bulk milk as a result of intramammary infections as well as non-infectious factors. The paper presents also the impact of on-farm management practices on the level of bulk milk somatic cell counts and presents quality indicators in bulk tank milk. At the farm level bulk milk bacterial infection takes place through three main sources: bacterial contamination from the external surface of the udder and teats, from the surface of the milking equipment, and from mastitis microorganisms within the udder. The threshold of 200,000 cells/ml identifies bacteriological negative quarters of the udder. The counts of mammary pathogens in bulk tank milk are relatively low, on average not exceeding 1,000 cfu/ml. Environmental pathogens predominate in bulk tank milk samples with somatic cells count <300 × 10(3) ml. PMID:22230979

  8. 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.

  9. Comparison of two transport systems available in Japan (TERUMO kenkiporter II and BBL Port-A-Cul) for maintenance of aerobic and anaerobic bacteria.

    PubMed

    Fujimoto, Daichi; Takegawa, Hiroshi; Doi, Asako; Sakizono, Kenji; Kotani, Yoko; Miki, Kanji; Naito, Takuya; Niki, Marie; Miyamoto, Junko; Tamai, Koji; Nagata, Kazuma; Nakagawa, Atsushi; Tachikawa, Ryo; Otsuka, Kojiro; Katakami, Nobuyuki; Tomii, Keisuke

    2014-01-01

    The kenkiporter II (KP II) transport system is commonly used in many hospitals in Japan for transporting bacterial specimens to microbiology laboratories. Recently, the BBL Port-A-Cul (PAC) fluid vial became available. However, no reports thus far have compared the effectiveness of these two transport systems. We chose 4 aerobic and facultative anaerobic bacteria as well as 8 anaerobic organisms, and prepared three strains of each bacterium in culture media for placement into PAC and KP II containers. We compared the effectiveness of each transport system for preserving each organism at 6, 24, and 48 h after inoculation at room temperature. Thirty-six strains out of 12 bacteria were used in this study. The PAC system yielded better recovery in quantity of organisms than the KP II system at 6, 24 and 48 h. More strains were significantly recovered with the PAC system than with the KP II at 24 h (36/36 vs. 23/36, P < 0.001) and 48 h (30/36 vs. 12/36, P < 0.001). The PAC system was better in the recovery of viable organisms counted at 24 and 48 h after inoculation compared with the KP II system. The PAC system may be recommended for the transfer of bacterial specimens in clinical settings. PMID:24462420

  10. 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

  11. Characteristics of a Novel Aerobic Denitrifying Bacterium, Enterobacter cloacae Strain HNR.

    PubMed

    Guo, Long-Jie; Zhao, Bin; An, Qiang; Tian, Meng

    2016-03-01

    A novel aerobic denitrifier strain HNR, isolated from activated sludge, was identified as Enterobacter cloacae by16S rRNA sequencing analysis. Glucose was considered as the most favorable C-source for strain HNR. The logistic equation well described the bacterial growth, yielding a maximum growth rate (μmax) of 0.283 h(-1) with an initial NO3 (-)-N concentration of 110 mg/L. Almost all NO3 (-)-N was removed aerobically within 30 h with an average removal rate of 4.58 mg N L(-1) h(-1). Nitrogen balance analysis revealed that proximately 70.8 % of NO3 (-)-N was removed as gas products and only 20.7 % was transformed into biomass. GC-MS result indicates that N2 was the end product of aerobic denitrification. The enzyme activities of nitrate reductase and nitrite reductase, which are related to the process of aerobic denitrification, were 0.0688 and 0.0054 U/mg protein, respectively. Thus, the aerobic denitrification of reducing NO3 (-) to N2 by strain HNR was demonstrated. The optimal conditions for nitrate removal were C/N ratio 13, pH value 8, shaking speed 127 rpm and temperature 30 °C. These findings show that E. cloacae strain HNR has a potential application on wastewater treatment to achieve nitrate removal under aerobic conditions. PMID:26573667

  12. Use of aerobic spores as a surrogate for cryptosporidium oocysts in drinking water supplies.

    PubMed

    Headd, Brendan; Bradford, Scott A

    2016-03-01

    Waterborne illnesses are a growing concern among health and regulatory agencies worldwide. The United States Environmental Protection Agency has established several rules to combat the contamination of water supplies by cryptosporidium oocysts, however, the detection and study of cryptosporidium oocysts is hampered by methodological and financial constraints. As a result, numerous surrogates for cryptosporidium oocysts have been proposed by the scientific community and efforts are underway to evaluate many of the proposed surrogates. The purpose of this review is to evaluate the suitability of aerobic bacterial spores to serve as a surrogate for cryptosporidium oocysts in identifying contaminated drinking waters. To accomplish this we present a comparison of the biology and life cycles of aerobic spores and oocysts and compare their physical properties. An analysis of their surface properties is presented along with a review of the literature in regards to the transport, survival, and prevalence of aerobic spores and oocysts in the saturated subsurface environment. Aerobic spores and oocysts share many commonalities with regard to biology and survivability, and the environmental prevalence and ease of detection make aerobic spores a promising surrogate for cryptosporidium oocysts in surface and groundwater. However, the long-term transport and release of aerobic spores still needs to be further studied, and compared with available oocyst information. In addition, the surface properties and environmental interactions of spores are known to be highly dependent on the spore taxa and purification procedures, and additional research is needed to address these issues in the context of transport. PMID:26734779

  13. Fast counting electronics for neutron coincidence counting

    DOEpatents

    Swansen, James E.

    1987-01-01

    An amplifier-discriminator is tailored to output a very short pulse upon an above-threshold input from a detector which may be a .sup.3 He detector. The short pulse output is stretched and energizes a light emitting diode (LED) to provide a visual output of operation and pulse detection. The short pulse is further fed to a digital section for processing and possible ORing with other like generated pulses. Finally, the output (or ORed output ) is fed to a derandomizing buffer which converts the rapidly and randomly occurring pulses into synchronized and periodically spaced-apart pulses for the accurate counting thereof. Provision is also made for the internal and external disabling of each individual channel of amplifier-discriminators in an ORed plurality of same.

  14. Fast counting electronics for neutron coincidence counting

    DOEpatents

    Swansen, J.E.

    1985-03-05

    An amplifier-discriminator is tailored to output a very short pulse upon an above-threshold input from a detector which may be a /sup 3/He detector. The short pulse output is stretched and energizes a light emitting diode (LED) to provide a visual output of operation and pulse detection. The short pulse is further fed to a digital section for processing and possible ORing with other like generated pulses. Finally, the output (or ORed output) is fed to a derandomizing buffer which converts the rapidly and randomly occurring pulses into synchronized and periodically spaced-apart pulses for the accurate counting thereof. Provision is also made for the internal and external disabling of each individual channel of amplifier-discriminators in an ORed plurality of same.

  15. Quantification, Distribution, and Possible Source of Bacterial Biofilm in Mouse Automated Watering Systems

    PubMed Central

    Meier, Thomas R; Maute, Carrie J; Cadillac, Joan M; Lee, Ji Young; Righter, Daniel J; Hugunin, Kelly MS; Deininger, Rolf A; Dysko, Robert C

    2008-01-01

    The use of automated watering systems for providing drinking water to rodents has become commonplace in the research setting. Little is known regarding bacterial biofilm growth within the water piping attached to the racks (manifolds). The purposes of this project were to determine whether the mouse oral flora contributed to the aerobic bacterial component of the rack biofilm, quantify bacterial growth in rack manifolds over 6 mo, assess our rack sanitation practices, and quantify bacterial biofilm development within sections of the manifold. By using standard methods of bacterial identification, the aerobic oral flora of 8 strains and stocks of mice were determined on their arrival at our animal facility. Ten rack manifolds were sampled before, during, and after sanitation and monthly for 6 mo. Manifolds were evaluated for aerobic bacterial growth by culture on R2A and trypticase soy agar, in addition to bacterial ATP quantification by bioluminescence. In addition, 6 racks were sampled at 32 accessible sites for evaluation of biofilm distribution within the watering manifold. The identified aerobic bacteria in the oral flora were inconsistent with the bacteria from the manifold, suggesting that the mice do not contribute to the biofilm bacteria. Bacterial growth in manifolds increased while they were in service, with exponential growth of the biofilm from months 3 to 6 and a significant decrease after sanitization. Bacterial biofilm distribution was not significantly different across location quartiles of the rack manifold, but bacterial levels differed between the shelf pipe and connecting elbow pipes. PMID:18351724

  16. Prevention of Bacterial Biofilms Formation on Urinary Catheter by Selected Plant Extracts.

    PubMed

    Adesina, T D; Nwinyi, O C; Olugbuyiro, J A O

    2015-02-01

    In this study, we investigated the feasibility of using Psidium guajava, Mangifera indica and Ocimum gratissimum leaf extracts in preventing Escherichia coli biofilm formation. The plants extractions were done with methanol under cold extraction. The various concentrations 5.0, 10.0 and 20.0 mg mL(-1) were used to coat 63 catheters under mild heat from water bath. Biofilm formation on the catheter was induced using cultures of E. coli. Biofilm formation was evaluated using aerobic plate count and turbidity at 600 nm. From the obtained results, Psidium guajava, Mangifera indica and Ocimum gratissimum delayed the onset of biofilm formation for a week. Ocimum gratissimum coated catheter had the highest inhibitory effect at 5.0, 10.0 and 20.0 mg mL(-1) with bacterial count ranging from 2.2 x 10(5)-7.0 x 10(4) and 5.7 x 10(5)-3.7 x10(5) for 120 and 128 h, respectively. The Psidium guajava coated catheter had the lowest inhibitory effect at 5.0, 10.0 and 20.0 mg mL(-1), with bacterial count ranging between 4.3 x 10(5)-1.9 x 10(3) and 7.7 x 10(5)-3.8 x 10(5) for 120 and 128 h, respectively. Despite the antimicrobial activities, the differences in the activity of these plant extracts were statistically not significant (p < 0.05). PMID:26364356

  17. Methods to determine aerobic endurance.

    PubMed

    Bosquet, Laurent; Léger, Luc; Legros, Patrick

    2002-01-01

    Physiological testing of elite athletes requires the correct identification and assessment of sports-specific underlying factors. It is now recognised that performance in long-distance events is determined by maximal oxygen uptake (V(2 max)), energy cost of exercise and the maximal fractional utilisation of V(2 max) in any realised performance or as a corollary a set percentage of V(2 max) that could be endured as long as possible. This later ability is defined as endurance, and more precisely aerobic endurance, since V(2 max) sets the upper limit of aerobic pathway. It should be distinguished from endurance ability or endurance performance, which are synonymous with performance in long-distance events. The present review examines methods available in the literature to assess aerobic endurance. They are numerous and can be classified into two categories, namely direct and indirect methods. Direct methods bring together all indices that allow either a complete or a partial representation of the power-duration relationship, while indirect methods revolve around the determination of the so-called anaerobic threshold (AT). With regard to direct methods, performance in a series of tests provides a more complete and presumably more valid description of the power-duration relationship than performance in a single test, even if both approaches are well correlated with each other. However, the question remains open to determine which systems model should be employed among the several available in the literature, and how to use them in the prescription of training intensities. As for indirect methods, there is quantitative accumulation of data supporting the utilisation of the AT to assess aerobic endurance and to prescribe training intensities. However, it appears that: there is no unique intensity corresponding to the AT, since criteria available in the literature provide inconsistent results; and the non-invasive determination of the AT using ventilatory and heart rate

  18. Whose interests count?

    PubMed

    Brudney, Daniel; Lantos, John D

    2014-10-01

    Whose interests should count and how should various interests be balanced at the pediatric patient's bedside? The interests of the child patient clearly count. Recently, however, many authors have argued that the family's interests also count. But how should we think about the interests of others? What does it mean to talk about "the family" in this context? Does it really just mean the interests of each individual family member? Or is the family itself a moral entity that has interests of its own independent of the interests of each of its members? Are such interests important only as they affect the patient's interest or also for their own sake? In this special supplement to Pediatrics, a group of pediatricians, philosophers, and lawyers grapple with these questions. They examine these issues from different angles and reach different conclusions. Jointly, they demonstrate the ethical importance and, above all, the ethical complexity of the family's role at the bedside. PMID:25274878

  19. Photon counting digital holography

    NASA Astrophysics Data System (ADS)

    Demoli, Nazif; Skenderović, Hrvoje; Stipčević, Mario; Pavičić, Mladen

    2016-05-01

    Digital holography uses electronic sensors for hologram recording and numerical method for hologram reconstruction enabling thus the development of advanced holography applications. However, in some cases, the useful information is concealed in a very wide dynamic range of illumination intensities and successful recording requires an appropriate dynamic range of the sensor. An effective solution to this problem is the use of a photon-counting detector. Such detectors possess counting rates of the order of tens to hundreds of millions counts per second, but conditions of recording holograms have to be investigated in greater detail. Here, we summarize our main findings on this problem. First, conditions for optimum recording of digital holograms for detecting a signal significantly below detector's noise are analyzed in terms of the most important holographic measures. Second, for time-averaged digital holograms, optimum recordings were investigated for exposures shorter than the vibration cycle. In both cases, these conditions are studied by simulations and experiments.

  20. On-farm and postharvest processing sources of bacterial contamination to melon rinds.

    PubMed

    Gagliardi, J V; Millner, P D; Lester, G; Ingram, D

    2003-01-01

    Multistate and international foodborne illness outbreaks, particularly involving cantaloupe and often involving rare Salmonella spp., have increased dramatically over the past 13 years. This study assessed the sources and extent of melon rind contamination in production fields and at processing and packing facilities. In the spring of 1999, cantaloupe (Cucumis melo L. [reticulatus group] cv. Cruiser) sampled from two sites in the Rio Grande River Valley showed that postharvest-processed melon rinds often had greater plate counts of bacterial contaminants than field-fresh melons. Cantaloupe in the field had 2.5 to 3.5 log CFU g(-1) rind total coliforms by aerobic plate counts, whereas washed melons had 4.0 to 5.0 log CFU g(-1). In the fall of 1999, coliforms on honeydew melons (C. melo [inodorous group] cv. Honey Brew) ranged from 2.6 to 3.7 log CFU g(-1) after processing, and total and fecal coliforms and enterococci never fell below 2.5 log CFU g(-1). A hydrocooler at another site contaminated cantaloupe rinds with up to 3.4 log CFU g(-1) total and fecal enterococci; a secondary rinse with chlorinated water incompletely removed these bacteria. Sources of coliforms and enterococci were at high levels in melon production soils, especially in furrows that were flood irrigated, in standing water at one field, and in irrigation water at both sites. At one processing facility, wash water pumped from the Rio Grande River may not have been sufficiently disinfected prior to use. Because soil, irrigation water, and process water were potential sources of bacterial contamination, monitoring and management on-farm and at processing and packing facilities should focus on water quality as an important control point for growers and packers to reduce bacterial contamination on melon rinds. PMID:12540185

  1. Bacterial Proteasomes

    PubMed Central

    Jastrab, Jordan B.; Darwin, K. Heran

    2015-01-01

    Interest in bacterial proteasomes was sparked by the discovery that proteasomal degradation is required for the pathogenesis of Mycobacterium tuberculosis, one of the world's deadliest pathogens. Although bacterial proteasomes are structurally similar to their eukaryotic and archaeal homologs, there are key differences in their mechanisms of assembly, activation, and substrate targeting for degradation. In this article, we compare and contrast bacterial proteasomes with their archaeal and eukaryotic counterparts, and we discuss recent advances in our understanding of how bacterial proteasomes function to influence microbial physiology. PMID:26488274

  2. Aerobic granular processes: Current research trends.

    PubMed

    Zhang, Quanguo; Hu, Jianjun; Lee, Duu-Jong

    2016-06-01

    Aerobic granules are large biological aggregates with compact interiors that can be used in efficient wastewater treatment. This mini-review presents new researches on the development of aerobic granular processes, extended treatments for complicated pollutants, granulation mechanisms and enhancements of granule stability in long-term operation or storage, and the reuse of waste biomass as renewable resources. A discussion on the challenges of, and prospects for, the commercialization of aerobic granular process is provided. PMID:26873285

  3. Accounting for What Counts

    ERIC Educational Resources Information Center

    Milner, Joseph O.; Ferran, Joan E.; Martin, Katharine Y.

    2003-01-01

    No Child Left Behind legislation makes it clear that outside evaluators determine what gets taught in the classroom. It is important to ensure they measure what truly counts in school. This fact is poignantly and sadly true for the under funded, poorly resourced, "low performing" schools that may be hammered by administration accountants in the…

  4. Making Research Count

    ERIC Educational Resources Information Center

    Appleby, Yvon; Kerwin, Marie; McCulloch, Sue

    2008-01-01

    Making research count in the education sector is often difficult to achieve as people, quite properly, question its relevance, purpose and impact. One of the significant barriers to research supporting practice in the lifelong learning sector is that funded research carried out in higher education institutions is frequently privileged above…

  5. LOW ENERGY COUNTING CHAMBERS

    DOEpatents

    Hayes, P.M.

    1960-02-16

    A beta particle counter adapted to use an end window made of polyethylene terephthalate was designed. The extreme thinness of the film results in a correspondingly high transmission of incident low-energy beta particles by the window. As a consequence, the counting efficiency of the present counter is over 40% greater than counters using conventional mica end windows.

  6. Counting digital filters

    NASA Technical Reports Server (NTRS)

    Zohar, S. (Inventor)

    1973-01-01

    Several embodiments of a counting digital filter of the non-recursive type are disclosed. In each embodiment two registers, at least one of which is a shift register, are included. The shift register received j sub x-bit data input words bit by bit. The kth data word is represented by the integer.

  7. What Counts as Evidence?

    ERIC Educational Resources Information Center

    Dougherty Stahl, Katherine A.

    2014-01-01

    Each disciplinary community has its own criteria for determining what counts as evidence of knowledge in their academic field. The criteria influence the ways that a community's knowledge is created, communicated, and evaluated. Situating reading, writing, and language instruction within the content areas enables teachers to explicitly…

  8. Dynamics Associated with Prolonged Ensiling and Aerobic Deterioration of Total Mixed Ration Silage Containing Whole Crop Corn

    PubMed Central

    Wang, Huili; Ning, Tingting; Hao, Wei; Zheng, Mingli; Xu, Chuncheng

    2016-01-01

    This study investigated the dynamics associated with prolonged ensiling and aerobic deterioration of whole crop corn (WCC) silages and total mixed ration (TMR) silages containing WCC (C-TMR silages) to clarify the differences that account for the enhanced aerobic stability of TMR silages. Laboratory-scale barrel silos were randomly opened after 7, 14, 28, and 56 d of ensiling and were subjected to analyses of fermentation quality, microbial and temperature dynamics during aerobic exposure. WCC and C-TMR silages were both well preserved and microorganisms were inhibited with prolonged ensiling, including lactic acid bacteria. Yeast were inhibited to below the detection limit of 500 cfu/g fresh matter within 28 d of ensiling. Aerobic stability of both silages was enhanced with prolonged ensiling, whereas C-TMR silages were more aerobically stable than WCC silages for the same ensiling period. Besides the high moisture content, the weak aerobic stability of WCC silage is likely attributable to the higher lactic acid content and yeast count, which result from the high water-soluble carbohydrates content in WCC. After silo opening, yeast were the first to propagate and the increase in yeast levels is greater than that of other microorganisms in silages before deterioration. Besides, increased levels of aerobic bacteria were also detected before heating of WCC silages. The temperature dynamics also indicated that yeast are closely associated with the onset of the aerobic deterioration of C-TMR silage, whereas for WCC silages, besides yeast, aerobic bacteria also function in the aerobic deterioration. Therefore, the inclusion of WCC might contribute to the survival of yeast during ensiling but not influence the role of yeast in deterioration of C-TMR silages. PMID:26732329

  9. Dynamics Associated with Prolonged Ensiling and Aerobic Deterioration of Total Mixed Ration Silage Containing Whole Crop Corn.

    PubMed

    Wang, Huili; Ning, Tingting; Hao, Wei; Zheng, Mingli; Xu, Chuncheng

    2016-01-01

    This study investigated the dynamics associated with prolonged ensiling and aerobic deterioration of whole crop corn (WCC) silages and total mixed ration (TMR) silages containing WCC (C-TMR silages) to clarify the differences that account for the enhanced aerobic stability of TMR silages. Laboratory-scale barrel silos were randomly opened after 7, 14, 28, and 56 d of ensiling and were subjected to analyses of fermentation quality, microbial and temperature dynamics during aerobic exposure. WCC and C-TMR silages were both well preserved and microorganisms were inhibited with prolonged ensiling, including lactic acid bacteria. Yeast were inhibited to below the detection limit of 500 cfu/g fresh matter within 28 d of ensiling. Aerobic stability of both silages was enhanced with prolonged ensiling, whereas C-TMR silages were more aerobically stable than WCC silages for the same ensiling period. Besides the high moisture content, the weak aerobic stability of WCC silage is likely attributable to the higher lactic acid content and yeast count, which result from the high water-soluble carbohydrates content in WCC. After silo opening, yeast were the first to propagate and the increase in yeast levels is greater than that of other microorganisms in silages before deterioration. Besides, increased levels of aerobic bacteria were also detected before heating of WCC silages. The temperature dynamics also indicated that yeast are closely associated with the onset of the aerobic deterioration of C-TMR silage, whereas for WCC silages, besides yeast, aerobic bacteria also function in the aerobic deterioration. Therefore, the inclusion of WCC might contribute to the survival of yeast during ensiling but not influence the role of yeast in deterioration of C-TMR silages. PMID:26732329

  10. Binary Interactions of Antagonistic Bacteria with Candida albicans Under Aerobic and Anaerobic Conditions.

    PubMed

    Benadé, Eliska; Stone, Wendy; Mouton, Marnel; Postma, Ferdinand; Wilsenach, Jac; Botha, Alfred

    2016-04-01

    We used both aerobic and anaerobic liquid co-cultures, prepared with Luria Bertani broth, to study the effect of bacteria on the survival of Candida albicans in the external environment, away from an animal host. The bacteria were represented by Aeromonas hydrophila, Bacillus cereus, Bacillus subtilis, Clostridium, Enterobacter, Klebsiella pneumoniae, Kluyvera ascorbata and Serratia marcescens. Under aerobic conditions, the yeast's growth was inhibited in the presence of bacterial growth; however, under anaerobic conditions, yeast and bacterial growth in co-cultures was similar to that observed for pure cultures. Subsequent assays revealed that the majority of bacterial strains aerobically produced extracellular hydrolytic enzymes capable of yeast cell wall hydrolysis, including chitinases and mannan-degrading enzymes. In contrast, except for the A. hydrophila strain, these enzymes were not detected in anaerobic bacterial cultures, nor was the antimicrobial compound prodigiosin found in anaerobic cultures of S. marcescens. When we suspended C. albicans cells in crude extracellular enzyme preparations from K. pneumoniae and S. marcescens, we detected no negative effect on yeast viability. However, we found that these preparations enhance the toxicity of prodigiosin towards the yeast, especially in combination with mannan-degrading enzymes. Analyses of the chitin and mannan content of yeast cell walls revealed that less chitin was produced under anaerobic than aerobic conditions; however, the levels of mannan, known for its low permeability, remained the same. The latter phenomenon, as well as reduced production of the bacterial enzymes and prodigiosin, may contribute to anaerobic growth and survival of C. albicans in the presence of bacteria. PMID:26566932

  11. Laboratory Study of Chemical Speciation of Mercury in Lake Sediment and Water under Aerobic and Anaerobic Conditions

    PubMed Central

    Regnell, Olof; Tunlid, Anders

    1991-01-01

    Chemical speciation and partitioning of radiolabeled HgCl2 were studied in model aquatic systems consisting of undisturbed eutrophic lake sediment and water in plastic cylinders. The cylinders were either gradually made anaerobic by a gentle flow of N2-CO2 or kept aerobic by air flow. The proportion of methylated 203Hg was significantly higher, in both water and sediment, in the anaerobic systems than in the aerobic systems. The composition and total concentration of fatty acids originating from bacterial phospholipids, as well as the concentration of vitamin B12, including related cobalamins, were similar in sediments from the anaerobic and aerobic systems. Bacterial cell numbers were, on average, 3.6 times higher in the anaerobic water columns than in the aerobic ones. Volatilization of 203Hg occurred in all systems except in an autoclaved control and was of similar magnitudes in the anaerobic and aerobic systems. Incorporation of 203Hg into the sediment was significantly faster in the aerobic systems than in the anaerobic systems. These results suggest that episodes of anoxia in bottom waters and sediment cause an increase in net mercury methylation and, hence, an increase in bioavailable mercury. PMID:16348444

  12. Bacterial flora of the schistosome vector snail Biomphalaria glabrata.

    PubMed Central

    Ducklow, H W; Boyle, P J; Maugel, P W; Strong, C; Mitchell, R

    1979-01-01

    The aerobic heterotrophic bacterial flora in over 200 individuals from 10 wild populations and 3 laboratory colonies of the schistosome vector snail Biomphalaria glabrata was examined. Internal bacterial densities were inversely proportional to snail size and were higher in stressed and laboratory-reared snails. The numerically predominant bacterial genera in individual snails included Pseudomonas, Acinetobacter, Aeromonas, Vibrio, and several members of the Enterobacteriaceae. Enterobacteriaceae seldom predominated in laboratory colonies. Our data suggest that Vibrio extorquens and a Pasteurella sp. tend to predominate in high-bacterial-density snails. These snails may be compromised and may harbor opportunistic snail pathogens. PMID:539821

  13. Bacterial flora of the schistosome vector snail Biomphalaria glabrata.

    PubMed

    Ducklow, H W; Boyle, P J; Maugel, P W; Strong, C; Mitchell, R

    1979-10-01

    The aerobic heterotrophic bacterial flora in over 200 individuals from 10 wild populations and 3 laboratory colonies of the schistosome vector snail Biomphalaria glabrata was examined. Internal bacterial densities were inversely proportional to snail size and were higher in stressed and laboratory-reared snails. The numerically predominant bacterial genera in individual snails included Pseudomonas, Acinetobacter, Aeromonas, Vibrio, and several members of the Enterobacteriaceae. Enterobacteriaceae seldom predominated in laboratory colonies. Our data suggest that Vibrio extorquens and a Pasteurella sp. tend to predominate in high-bacterial-density snails. These snails may be compromised and may harbor opportunistic snail pathogens. PMID:539821

  14. Experimental determination of carbon dioxide evolution during aerobic composting of agro-wastes.

    PubMed

    Tripathi, Shilpa; Srivastava, J K

    2012-10-01

    This work aims at optimal composting of agro-wastes like sugarcane bagasse, wood straw and soya husk. A mixture of these substances along with small quantity of food waste as the seed was composted aerobically and carbon dioxide evolved was determined experimentally using a composting system comprising aerobic digester, operating in near-optimal conditions with regard to adequacy of oxygen and temperature in the system. During aerobic composting of agro-waste carbon dioxide is produced due to degradation of different carbon fractions in the substrate. Carbon dioxide production rate, which is a measure of bacterial/fungal activity in composting systems, can be related to various process parameters like different carbon fractions present in the substrate and their reaction rates, progress and termination of compost phenomenon and stabilization of organic matter. This gives a balanced compromise between complexity of mathematical model and extensive experimentation, and can be used for determining optimum conditions for composting. PMID:25151714

  15. Survival of anaerobic and aerobic bacteria in a nonsupportive gassed transport system.

    PubMed Central

    Chow, A W; Cunningham, P J; Guze, L B

    1976-01-01

    Survival of anaerobic and aerobic bacteria in a commercially available, non-supportive, gassed (oxygen-free) transport container (Anaport) was evaluated quantitatively. Saline-suspended obligate anaerobes survived significantly better in the gassed container in aerobic control tubes (P less than 0.025, t test), and counts were virtually unchanged after 8 h of holding. Similarly, initial counts and relative proportions of a mixture of Bacteroides fragilis and Staphylococcus aureus were maintained for 72 h. The value of the gassed transport system was less apparent when microorganisms were suspended in nutrient broth. The major advantage of the gassed transport system appears to be for holding of specimens collected by saline irrigation. PMID:1254710

  16. Characterization of bacterial communities and functions of two submerged soils from San Vitale park (Italy)

    NASA Astrophysics Data System (ADS)

    Mocali, Stefano; Chiellini, Carolina; Lagomarsino, Alessandra; Ferronato, Chiara; Vittori Antisari, Livia; Vianello, Gilmo

    2015-04-01

    Subaqueous soils has been introduced in the last edition of the Keys to Soil Taxonomy (Soil surveystaff, 2014), to describe soils covered by a water column of up to 2.5 m where different pedogenetic processes can be recognized. However, the role of bacterial community structure and function in such environments and its potential use as pedogenetic indicator is still largely unknown. Two submerged soils (WAS-2 and WAS-4) were collected from San Vitale park (Italy), a site where the evolution of the landscape from subaqueous wetland to interdunal and dunal system, and the interfacing of freshwater with saltwater, made this site particularly suitable for examining the pedogenetic indicators which can characterize and predict the soil hydromorphism in trasitional ecosystems. The two soils were classified and their physicochemical and morphological features were investigated. Selective media were used to isolate both culturable aerobic and anaerobic (microaerophilic) bacteria associated with each horizon. In WAS-2 seven horizons were identified (depths 4-0, 0-6, 6-13, 13-20, 20-36, 36-59/60, and 59/60-83 cm) while in WAS-4, five horizons were identified (depths 0-14, 14-20, 20-40, 40-45, 45-100 cm) for a total of 12 horizons (samples). For each sample, aerobic bacterial plate count was performed on solid LB medium, coupled with microaerophilic bacterial plate count either on SA500 minimal medium and AYE medium (0.5% soft agar each). Molecular identification (16S rRNA gene sequencing) of ~100 strains isolated from each of the three used medium was performed, for a total of ~300 strains for each sample. To complete the characterization of the microbial communities in all horizons, Next Generation Sequencing (NGS) analysis was carried out with 454 platform on each of the 12 samples. Moreover, the N2O and CH4 emissions were determined from each pedon. All the parameters were used to highlight the similarities and the differences between and within the pedons. The results

  17. Mixed response in bacterial and biochemical variables to simulated sand mining in placer-rich beach sediments, Ratnagiri, West coast of India.

    PubMed

    Fernandes, Christabelle E G; Das, Anindita; Nath, B N; Faria, Daphne G; Loka Bharathi, P A

    2012-05-01

    We investigated the influence on bacterial community and biochemical variables through mechanical disturbance of sediment-akin to small-scale mining in Kalbadevi beach, Ratnagiri, a placer-rich beach ecosystem which is a potential mining site. Changes were investigated by comparing three periods, namely phase I before disturbance, phase II just after disturbance, and phase III 24 h after disturbance as the bacterial generation time is ≤7 h. Cores from dune, berm, high-, mid-, and low-tide were examined for changes in distribution of total bacterial abundance, total direct viability (counts under aerobic and anaerobic conditions), culturability and biochemical parameters up to 40 cm depth. Results showed that bacterial abundance decreased by an order from 10(6) cells g(-1) sediment, while, viability reduced marginally. Culturability on different-strength nutrient broth increased by 155% during phase II. Changes in sedimentary proteins, carbohydrates, and lipids were marked at berm and dune and masked at other levels by tidal influence. Sedimentary ATP reduced drastically. During phase III, Pearson's correlation between these variables evolved from non-significant to significant level. Thus, simulated disturbance had a mixed effect on bacterial and biochemical variables of the sediments. It had a negative impact on bacterial abundance, viability and ATP but positive impact on culturability. Viability, culturability, and ATP could act as important indicators reflecting the disturbance in the system at short time intervals. Culturability, which improved by an order, could perhaps be a fraction that contributes to restoration of the system at bacterial level. This baseline information about the potential mining site could help in developing rational approach towards sustainable harnessing of resources with minimum damage to the ecosystem. PMID:21713495

  18. Bacterial pathogen indicators regrowth and reduced sulphur compounds' emissions during storage of electro-dewatered biosolids.

    PubMed

    Navab-Daneshmand, Tala; Enayet, Samia; Gehr, Ronald; Frigon, Dominic

    2014-10-01

    Electro-dewatering (ED) increases biosolids dryness from 10-15 to 30-50%, which helps wastewater treatment facilities control disposal costs. Previous work showed that high temperatures due to Joule heating during ED inactivate total coliforms to meet USEPA Class A biosolids requirements. This allows biosolids land application if the requirements are still met after the storage period between production and application. In this study, we examined bacterial regrowth and odour emissions during the storage of ED biosolids. No regrowth of total coliforms was observed in ED biosolids over 7d under aerobic or anaerobic incubations. To mimic on-site contamination during storage or transport, ED samples were seeded with untreated sludge. Total coliform counts decreased to detection limits after 4d in inoculated samples. Olfactometric analysis of ED biosolids odours showed that odour concentrations were lower compared to the untreated and heat-treated control biosolids. Furthermore, under anaerobic conditions, odorous reduced sulphur compounds (methanethiol, dimethyl sulphide and dimethyl disulphide) were produced by untreated and heat-treated biosolids, but were not detected in the headspaces above ED samples. The data demonstrate that ED provides advantages not only as a dewatering technique, but also for producing biosolids with lower microbial counts and odour levels. PMID:25065797

  19. Effect of Gaseous Ozone Exposure on the Bacteria Counts and Oxidative Properties of Ground Hanwoo Beef at Refrigeration Temperature

    PubMed Central

    Cho, Youngjae; Hahn, Tae-Wook

    2014-01-01

    This study was designed to elucidate the effect of ozone exposure on the bacteria counts and oxidative properties of ground Hanwoo beef contaminated with Escherichia coli O157:H7 at refrigeration temperature. Ground beef was inoculated with 7 Log CFU/g of E. coli O157:H7 isolated from domestic pigs and was then subjected to ozone exposure (10×10−6 kg O3 h−1) at 4℃ for 3 d. E. coli O157:H7, total aerobic and anaerobic bacterial growth and oxidative properties including instrumental color changes, TBARS, catalase (CAT) and glutathione peroxidase (GPx) activity were evaluated. Ozone exposure significantly prohibited (p<0.05) the growths of E. coli O157:H7, total aerobic and anaerobic bacteria in ground beef samples during storage. Ozone exposure reduced (p<0.05) the CIE a* value of samples over storage time. The CIE L* and CIE b* values of the samples fluctuated over storage time, and ozone had no clear effect. Ozone exposure increased the TBARS values during 1 to 3 d of storage (p<0.05). The CAT and GPx enzyme activities were not affected by ozone exposure until 2 and 3 d of storage, respectively. This study provides information about the use of ozone exposure as an antimicrobial agent for meat under refrigerated storage. The results of this study provide a foundation for the further application of ozone exposure by integrating an ozone generator inside a refrigerator. Further studies regarding the ozone concentrations and exposure times are needed. PMID:26761291

  20. Effect of Gaseous Ozone Exposure on the Bacteria Counts and Oxidative Properties of Ground Hanwoo Beef at Refrigeration Temperature.

    PubMed

    Cho, Youngjae; Muhlisin; Choi, Ji Hye; Hahn, Tae-Wook; Lee, Sung Ki

    2014-01-01

    This study was designed to elucidate the effect of ozone exposure on the bacteria counts and oxidative properties of ground Hanwoo beef contaminated with Escherichia coli O157:H7 at refrigeration temperature. Ground beef was inoculated with 7 Log CFU/g of E. coli O157:H7 isolated from domestic pigs and was then subjected to ozone exposure (10×10(-6) kg O3 h(-1)) at 4℃ for 3 d. E. coli O157:H7, total aerobic and anaerobic bacterial growth and oxidative properties including instrumental color changes, TBARS, catalase (CAT) and glutathione peroxidase (GPx) activity were evaluated. Ozone exposure significantly prohibited (p<0.05) the growths of E. coli O157:H7, total aerobic and anaerobic bacteria in ground beef samples during storage. Ozone exposure reduced (p<0.05) the CIE a* value of samples over storage time. The CIE L* and CIE b* values of the samples fluctuated over storage time, and ozone had no clear effect. Ozone exposure increased the TBARS values during 1 to 3 d of storage (p<0.05). The CAT and GPx enzyme activities were not affected by ozone exposure until 2 and 3 d of storage, respectively. This study provides information about the use of ozone exposure as an antimicrobial agent for meat under refrigerated storage. The results of this study provide a foundation for the further application of ozone exposure by integrating an ozone generator inside a refrigerator. Further studies regarding the ozone concentrations and exposure times are needed. PMID:26761291

  1. Comparison of Leachate Quality from Aerobic and Anaerobic Municipal Solid Waste Bioreactors

    NASA Astrophysics Data System (ADS)

    Borglin, S. E.; Hazen, T. C.; Oldenburg, C. M.

    2002-12-01

    Municipal solid waste landfills are becoming a drain on the resources of local municipalities as the requirements for stabilization and containment become increasingly stringent. Current regulations limit the moisture in the landfill to minimize leachate production and lower the potential for release of leachate to the environment. Recent research has shown that addition and recycling of moisture in the waste optimizes the biodegradation of stabilization and also provides a means for leachate treatment. This study compares the characteristics of leachate produced from aerobic and anaerobic laboratory bioreactors, and leachate collected from a full-scale anaerobic bioreactor. The laboratory reactors consisted of 200-liter tanks filled with fresh waste materials with the following conditions: (a) aerobic (air injection with leachate recirculation), (b) anaerobic (leachate recirculation). The leachate from the reactors was monitored for metals, nutrients, organic carbon, and microbiological activity for up to 500 days. Leachate from the aerobic tank had significantly lower concentrations of all potential contaminants, both organic and metal, after only a few weeks of operation. Metals leaching was low throughout the test period for the aerobic tanks, and decreased over time for the anaerobic tanks. Organic carbon as measured by BOD, COD, TOC, and COD were an order of magnitude higher in the leachate from the anaerobic system. Microbiological assessment by lipid analysis, enzyme activity assays, and cell counts showed high biomass and diversity in both the aerobic and anaerobic bioreactors, with higher activity in the anaerobic leachate. Results from the full-scale anaerobic bioreactor were not significantly different from those of the laboratory anaerobic bioreactor. The reduction in noxious odors was a significant advantage of the aerobic system. These results suggest that aerobic management of landfills could reduce or eliminate the need for leachate treatment

  2. Effect of aerobic exercise on premenstrual symptoms, haematological and hormonal parameters in young women.

    PubMed

    El-Lithy, A; El-Mazny, A; Sabbour, A; El-Deeb, A

    2015-05-01

    The objective of this study was to investigate the effect of aerobic exercise on premenstrual symptoms, haematological and hormonal parameters in young women. A total of 30 participants aged 16-20 years and complaining of premenstrual syndrome (PMS) were randomly assigned into two groups: a control group received vitamin B6 and Ca supplements once daily and a study group received the same medical treatment and participated in treadmill training three times per week for 3 months. A premenstrual syndrome questionnaire (MSQ), complete blood picture and hormone assays were performed for the assessment of all participants at the start and after the end of the treatment course. The study group showed a significant decrease in all post-treatment subscale symptoms, scores and total score. Haemoglobin, haematocrit, red cell count and platelet count were significantly increased, while mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) and white blood cell count showed no significant differences. There was also a significant decrease in prolactin, oestradiol and progesterone levels. In conclusion, aerobic exercise increases haemoglobin, haematocrit, red cell count and platelet count, and decreases levels of prolactin, oestradiol and progesterone, resulting in improvement of fatigue, impaired concentration, confusion and most premenstrual symptoms. PMID:25279689

  3. Counting every quantum

    PubMed Central

    Sakitt, B.

    1972-01-01

    1. Human subjects were asked to rate both blanks and very dim flashes of light under conditions of complete dark adaptation at 7° in the periphery. The ratings used were 0, 1, 2, 3, 4, 5, and 6. 2. For one subject (B.S.) the distributions of ratings were approximately Poisson distributions. The data were consistent with each rating being the actual number of effective quantal absorptions plus the number of noise events. This subject was presumably able to count every rod signal (effective absorptions plus noise). 3. For two other subjects, the data were consistent with the ratings being one less (L.F.) and two less (K.D.) than the number of effective absorptions plus noise. They were able to count every rod signal beginning with 2 and 3 respectively. A fourth subject's erratic data could not be fitted. 4. The fraction of quanta incident at the cornea that resulted in a rod signal was estimated to be about 0·03 which is consistent with physical estimates of effective absorption for that retinal region. 5. A simulated forced choice experiment leads to an absolute threshold about 0·40 log units below the normal yes-no absolute threshold. This and other results indicate that subjects can use the sensory information they receive even when only 1, 2 or 3 quanta are effectively absorbed, depending on the individual. Humans may be able to count every action potential or every discrete burst of action potentials in some critical neurone. PMID:5046137

  4. Peroxide test strips detect added hydrogen peroxide in raw milk at levels affecting bacterial load.

    PubMed

    Martin, Nicole H; Friedlander, Adam; Mok, Allen; Kent, David; Wiedmann, Martin; Boor, Kathryn J

    2014-10-01

    Hydrogen peroxide (H2O2) has a long-established history of use as a preservative in milk worldwide. The use of H2O2 to activate the inherent lactoperoxidase enzyme system has dramatically improved the quality of raw dairy products in areas in which cooling is not widely available. In the United States, however, where refrigeration is widely available, the addition of H2O2 to milk is not permitted, with the exception of certain applications prior to cheesemaking and during the preparation of modified whey. Due to the relatively quick deterioration of H2O2 in fluid milk, the detection of raw milk adulterated with the compound can be challenging. In this study we evaluated (i) total aerobic bacterial counts and (ii) ability of peroxide test strips to detect H2O2 in raw milk with various concentrations (0, 100, 300, 500, 700, and 900 ppm) of added H2O2, incubated at both 6 and 21°C for 0, 24, and 48 h. Results showed that at both 6 and 21°C the H2O2 concentration and time had a significant effect on bacterial loads in raw milk. Additionally, commercially available test strips were able to detect H2O2 in raw milk, with predicted probability of >90%, immediately after addition and after 24 and 48 h for the higher concentrations used, offering a viable method for detecting raw milk adulteration with H2O2. PMID:25285503

  5. Bacterial communities in an ultrapure water containing storage tank of a power plant.

    PubMed

    Bohus, Veronika; Kéki, Zsuzsa; Márialigeti, Károly; Baranyi, Krisztián; Patek, Gábor; Schunk, János; Tóth, Erika M

    2011-12-01

    Ultrapure waters (UPWs) containing low levels of organic and inorganic compounds provide extreme environment. On contrary to that microbes occur in such waters and form biofilms on surfaces, thus may induce corrosion processes in many industrial applications. In our study, refined saltless water (UPW) produced for the boiler of a Hungarian power plant was examined before and after storage (sampling the inlet [TKE] and outlet [TKU] waters of a storage tank) with cultivation and culture independent methods. Our results showed increased CFU and direct cell counts after the storage. Cultivation results showed the dominance of aerobic, chemoorganotrophic α-Proteobacteria in both samples. In case of TKU sample, a more complex bacterial community structure could be detected. The applied molecular method (T-RFLP) indicated the presence of a complex microbial community structure with changes in the taxon composition: while in the inlet water sample (TKE) α-Proteobacteria (Sphingomonas sp., Novosphingobium hassiacum) dominated, in the outlet water sample (TKU) the bacterial community shifted towards the dominance of α-Proteobacteria (Rhodoferax sp., Polynucleobacter sp., Sterolibacter sp.), CFB (Bacteroidetes, formerly Cytophaga-Flavobacterium-Bacteroides group) and Firmicutes. This shift to the direction of fermentative communities suggests that storage could help the development of communities with an increased tendency toward corrosion. PMID:22207294

  6. Aerobic granular sludge mediated biodegradation of an organophosphorous ester, dibutyl phosphite.

    PubMed

    Kiran Kumar Reddy, G; Nancharaiah, Yarlagadda Venkata; Venugopalan, Vayalam Purath

    2014-10-01

    Dibutyl phosphite, an organophosphorous compound, finds applications in different chemical industries and processes. Here, we report an efficient approach of biodegradation to be eventually used in bioremediation of dibutyl phosphite. Aerobic granules capable of dibutyl phosphite biodegradation were cultivated in a sequencing batch reactor (SBR). The SBR was operated with a 24-h cycle by feeding with dibutyl phosphite as a cosubstrate along with acetate. During the course of the SBR operation, aerobic granules of 0.9 ± 0.3 mm size were developed. Complete biodegradation of 1.4, 2 and 3 mM of dibutyl phosphite was achieved in 4, 5 and 8 h, respectively, accompanied by stoichiometric release of phosphite (H3 PO3). Phosphatase activity in the dibutyl phosphite-degrading granular biomass was 3- and 1.5-fold higher as compared to the activated sludge (seed biomass) and acetate-fed aerobic granules, respectively, indicating involvement in the hydrolysis of dibutyl phosphite. Microbial community analysis by t-RFLP showed the presence of 12 different bacterial types. Two bacterial strains capable of growth on dibutyl phosphite as sole carbon source were isolated and characterized as Acidovorax sp. and Sphingobium sp. The results show that aerobic microbial granules based process is suitable for the treatment of dibutyl phosphite contaminated water. PMID:25135363

  7. Aerobic granulation strategy for bioaugmentation of a sequencing batch reactor (SBR) treating high strength pyridine wastewater.

    PubMed

    Liu, Xiaodong; Chen, Yan; Zhang, Xin; Jiang, Xinbai; Wu, Shijing; Shen, Jinyou; Sun, Xiuyun; Li, Jiansheng; Lu, Lude; Wang, Lianjun

    2015-09-15

    Aerobic granules were successfully cultivated in a sequencing batch reactor (SBR), using a single bacterial strain Rhizobium sp. NJUST18 as the inoculum. NJUST18 presented as both a good pyridine degrader and an efficient autoaggregator. Stable granules with diameter of 0.5-1 mm, sludge volume index of 25.6 ± 3.6 mL g(-1) and settling velocity of 37.2 ± 2.7 m h(-1), were formed in SBR following 120-day cultivation. These granules exhibited excellent pyridine degradation performance, with maximum volumetric degradation rate (Vmax) varied between 1164.5 mg L(-1) h(-1) and 1867.4 mg L(-1) h(-1). High-throughput sequencing analysis exhibited a large shift in microbial community structure, since the SBR was operated under open condition. Paracoccus and Comamonas were found to be the most predominant species in the aerobic granule system after the system had stabilized. The initially inoculated Rhizobium sp. lost its dominance during aerobic granulation. However, the inoculation of Rhizobium sp. played a key role in the start-up process of this bioaugmentation system. This study demonstrated that, in addition to the hydraulic selection pressure during settling and effluent discharge, the selection of aggregating bacterial inocula is equally important for the formation of the aerobic granule. PMID:25897697

  8. Aerobic Fitness for the Moderately Retarded.

    ERIC Educational Resources Information Center

    Bauer, Dan

    1981-01-01

    Intended for physical education teachers, the booklet offers ideas for incorporating aerobic conditioning into programs for moderately mentally retarded students. An explanation of aerobic fitness and its benefits is followed by information on initiating a fitness program with evaluation of height, weight, body fat, resting heart rate, and…

  9. 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.

  10. Skeletal Muscle Hypertrophy after Aerobic Exercise Training

    PubMed Central

    Konopka, Adam R.; Harber, Matthew P.

    2014-01-01

    Current dogma suggests aerobic exercise training has minimal effect on skeletal muscle size. We and others have demonstrated that aerobic exercise acutely and chronically alters protein metabolism and induces skeletal muscle hypertrophy. These findings promote an antithesis to the status quo by providing novel perspective on skeletal muscle mass regulation and insight into exercise-countermeasures for populations prone to muscle loss. PMID:24508740

  11. Aerobic Dancing--A Rhythmic Sport.

    ERIC Educational Resources Information Center

    Sorensen, Jacki

    Fitness programs now and in the future must offer built-in cardiovascular conditioning, variety, novelty, and change to meet the physical, mental, and emotional needs of our society. Aerobic dancing (dancing designed to train and strengthen the heart, lungs, and vascular system) is one of the first indoor group Aerobic exercise programs designed…

  12. Corticosteroids for Bacterial Keratitis

    PubMed Central

    Srinivasan, Muthiah; Mascarenhas, Jeena; Rajaraman, Revathi; Ravindran, Meenakshi; Lalitha, Prajna; Glidden, David V.; Ray, Kathryn J.; Hong, Kevin C.; Oldenburg, Catherine E.; Lee, Salena M.; Zegans, Michael E.; McLeod, Stephen D.; Lietman, Thomas M.; Acharya, Nisha R.

    2013-01-01

    Objective To determine whether there is a benefit in clinical outcomes with the use of topical corticosteroids as adjunctive therapy in the treatment of bacterial corneal ulcers. Methods Randomized, placebo-controlled, double-masked, multicenter clinical trial comparing prednisolone sodium phosphate, 1.0%, to placebo as adjunctive therapy for the treatment of bacterial corneal ulcers. Eligible patients had a culture-positive bacterial corneal ulcer and received topical moxifloxacin for at least 48 hours before randomization. Main Outcome Measures The primary outcome was best spectacle-corrected visual acuity (BSCVA) at 3 months from enrollment. Secondary outcomes included infiltrate/scar size, reepithelialization, and corneal perforation. Results Between September 1, 2006, and February 22, 2010, 1769 patients were screened for the trial and 500 patients were enrolled. No significant difference was observed in the 3-month BSCVA (−0.009 logarithm of the minimum angle of resolution [logMAR]; 95% CI, −0.085 to 0.068; P = .82), infiltrate/scar size (P = .40), time to reepithelialization (P = .44), or corneal perforation (P > .99). A significant effect of corticosteroids was observed in subgroups of baseline BSCVA (P = .03) and ulcer location (P = .04). At 3 months, patients with vision of counting fingers or worse at baseline had 0.17 logMAR better visual acuity with corticosteroids (95% CI, −0.31 to −0.02; P = .03) compared with placebo, and patients with ulcers that were completely central at baseline had 0.20 logMAR better visual acuity with corticosteroids (−0.37 to −0.04; P = .02). Conclusions We found no overall difference in 3-month BSCVA and no safety concerns with adjunctive corticosteroid therapy for bacterial corneal ulcers. Application to Clinical Practice Adjunctive topical corticosteroid use does not improve 3-month vision in patients with bacterial corneal ulcers. PMID:21987582

  13. Pedometers and aerobic capacity: evaluating an elementary after-school running program.

    PubMed

    Wanless, Elizabeth; Judge, Lawrence W; Dieringer, Shannon T; Bellar, David; Johnson, James; Plummer, Sheli

    2014-01-01

    Childhood obesity affects 1 of every 6 youth in the United States. One contributing factor to this statistic is a lack of physical activity (PA). Demands related to accountability which are placed on educators to demonstrate academic achievement often result in resistance to allocating time during the school day for PA. One possible solution is to consider utilizing time after school to integrate PA programs. The purpose of this study was to assess the impact of a 12-week after-school pedometer-focused PA program on aerobic capacity and to examine the relationship between step count and aerobic capacity in elementary school aged children. A group of elementary students (n = 24; 9.5 ± 0.9 years) participated in a 12-week pedometer-focused PA program that included pretraining and posttraining fitness testing via the 20-meter version of the PACER test. Paired sample t-tests revealed significant differences between the pretest (M = 21.0 laps, SD = 9.9) and posttest (M = 25.2 laps, SD = 12.2) scores (t = 4.04, P ≤ 0.001). A Pearson correlation revealed no significant relationship between individual step count and the difference between PACER pre- and posttest (r = 0.318, P = 0.130). The program improved aerobic capacity, but an increase in pedometer-calculated step count was not a predictor. PMID:24723803

  14. Validation of the Peel Plate™ AC for Detection of Total Aerobic Bacteria in Dairy and Nondairy Products.

    PubMed

    Salter, Robert S; Durbin, Gregory W; Bird, Patrick; Fisher, Kiel; Crowley, Erin; Hammack, Thomas; Chen, Yi; Clark, Dorn; Ziemer, Wayne

    2016-01-01

    Peel Plate™ AC (aerobic count) is a low-profile plastic 47 mm culture dish with adhesive top that contains a dried standard plate count medium with oxidation/reduction indicator triphenyl tetrazolium chloride (TTC) that turns red with dehydrogenase enzyme activity of growing aerobic bacteria. The method provides a conventional quantitative count with simple rehydration and incubation for 48 ± 3 h at 35 ± 1°C for most food matrixes and 32 ± 1°C for 48 ± 3 h for dairy products. Dairy matrixes claimed and supported with total aerobic count data are whole milk, skim milk, chocolate milk (2% fat), light cream (20% fat), pasteurized whole goat milk, ultra-high temperature pasteurized milk, nonfat dried milk, lactose-reduced milk, strawberry milk, raw cow milk, raw goat milk, raw sheep milk, condensed skim milk, and vanilla ice cream. Food matrixes claimed for aerobic count detection are raw ground beef, environmental sponge of stainless steel, raw ground turkey, dry dog food, liquid whole pasteurized eggs, milk chocolate, poultry carcass rinse, and large animal carcass sponge. The method has been independently evaluated for aerobic count in dairy products: whole milk, skim milk, chocolate milk, and light cream. The method was also independently evaluated for aerobic count in food matrixes: ground beef and sponge rinse from stainless steel surfaces. In the matrix study, each matrix was assessed separately at each contamination level in comparison to an appropriate reference method. Colony counts were determined for each level and then log10-transformed. The transformed data were evaluated for repeatability, mean comparison between methods with 95% confidence interval (CI), and r(2). A CI range of (-0.5, 0.5) on the mean difference was used as the acceptance criterion to establish significant statistical differences between methods. The evaluations demonstrate that the Peel Plate AC provides no statistical differences across most of the matrixes with r(2) > 0

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

    PubMed Central

    2011-01-01

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

  16. Bacterial Keratitis

    MedlinePlus

    ... very quickly, and if left untreated, can cause blindness. The bacteria usually responsible for this type of ... to intense ultraviolet radiation exposure, e.g. snow blindness or welder's arc eye). Next Bacterial Keratitis Symptoms ...

  17. Antibiotic Susceptibility Pattern of Aerobic and Anaerobic Bacteria Isolated From Surgical Site Infection of Hospitalized Patients

    PubMed Central

    Akhi, Mohammad Taghi; Ghotaslou, Reza; Beheshtirouy, Samad; Asgharzadeh, Mohammad; Pirzadeh, Tahereh; Asghari, Babak; Alizadeh, Naser; Toloue Ostadgavahi, Ali; Sorayaei Somesaraei, Vida; Memar, Mohammad Yousef

    2015-01-01

    Background: Surgical Site Infections (SSIs) are infections of incision or deep tissue at operation sites. These infections prolong hospitalization, delay wound healing, and increase the overall cost and morbidity. Objectives: This study aimed to investigate anaerobic and aerobic bacteria prevalence in surgical site infections and determinate antibiotic susceptibility pattern in these isolates. Materials and Methods: One hundred SSIs specimens were obtained by needle aspiration from purulent material in depth of infected site. These specimens were cultured and incubated in both aerobic and anaerobic condition. For detection of antibiotic susceptibility pattern in aerobic and anaerobic bacteria, we used disk diffusion, agar dilution, and E-test methods. Results: A total of 194 bacterial strains were isolated from 100 samples of surgical sites. Predominant aerobic and facultative anaerobic bacteria isolated from these specimens were the members of Enterobacteriaceae family (66, 34.03%) followed by Pseudomonas aeruginosa (26, 13.4%), Staphylococcus aureus (24, 12.37%), Acinetobacter spp. (18, 9.28%), Enterococcus spp. (16, 8.24%), coagulase negative Staphylococcus spp. (14, 7.22%) and nonhemolytic streptococci (2, 1.03%). Bacteroides fragilis (26, 13.4%), and Clostridium perfringens (2, 1.03%) were isolated as anaerobic bacteria. The most resistant bacteria among anaerobic isolates were B. fragilis. All Gram-positive isolates were susceptible to vancomycin and linezolid while most of Enterobacteriaceae showed sensitivity to imipenem. Conclusions: Most SSIs specimens were polymicrobial and predominant anaerobic isolate was B. fragilis. Isolated aerobic and anaerobic strains showed high level of resistance to antibiotics. PMID:26421133

  18. Dependence of structure stability and integrity of aerobic granules on ATP and cell communication.

    PubMed

    Jiang, Bo; Liu, Yu

    2013-06-01

    Aerobic granules are dense and compact microbial aggregates with various bacterial species. Recently, aerobic granulation technology has been extensively explored for treatment of municipal and industrial wastewaters. However, little information is currently available with regard to their structure stability and integrity at levels of energy metabolism and cell communication. In the present study, a typical chemical uncoupler, 3,3',4',5-tetrachlorosalicylanilide with the power to dissipate proton motive force and subsequently inhibit adenosine triphosphate (ATP) generation, was used to investigate possible roles of ATP and cell communication in maintaining the structure stability and integrity of aerobic granules. It was found that inhibited ATP synthesis resulted in the reduced production of autoinducer-2 and N-acylhomoserine lactones essential for cell communication, while lowered extracellular polymeric substance (EPS) production was also observed. As a consequence, aerobic granules appeared to break up. This study showed that ATP-dependent quorum sensing and EPS were essential for sustaining the structure stability and integrity of aerobic granules. PMID:23011346

  19. Counting single photoactivatable fluorescent molecules by photoactivated localization microscopy (PALM).

    PubMed

    Lee, Sang-Hyuk; Shin, Jae Yen; Lee, Antony; Bustamante, Carlos

    2012-10-23

    We present a single molecule method for counting proteins within a diffraction-limited area when using photoactivated localization microscopy. The intrinsic blinking of photoactivatable fluorescent proteins mEos2 and Dendra2 leads to an overcounting error, which constitutes a major obstacle for their use as molecular counting tags. Here, we introduce a kinetic model to describe blinking and show that Dendra2 photobleaches three times faster and blinks seven times less than mEos2, making Dendra2 a better photoactivated localization microscopy tag than mEos2 for molecular counting. The simultaneous activation of multiple molecules is another source of error, but it leads to molecular undercounting instead. We propose a photoactivation scheme that maximally separates the activation of different molecules, thus helping to overcome undercounting. We also present a method that quantifies the total counting error and minimizes it by balancing over- and undercounting. This unique method establishes that Dendra2 is better for counting purposes than mEos2, allowing us to count in vitro up to 200 molecules in a diffraction-limited spot with a bias smaller than 2% and an uncertainty less than 6% within 10 min. Finally, we demonstrate that this counting method can be applied to protein quantification in vivo by counting the bacterial flagellar motor protein FliM fused to Dendra2. PMID:23045631

  20. Exploring the Bacterial Diversity of Belgian Steak Tartare Using Metagenetics and Quantitative Real-Time PCR Analysis.

    PubMed

    Delhalle, L; Korsak, N; Taminiau, B; Nezer, C; Burteau, S; Delcenserie, V; Poullet, J B; Daube, G

    2016-02-01

    Steak tartare is a popular meat dish in Belgium. It is prepared with raw minced beef and is eaten with sauce, vegetables, and spices. Because it contains raw meat, steak tartare is highly prone to bacterial spoilage. The objective of this study was to explore the diversity of bacterial flora in steak tartare in Belgium according to the source and to determine which bacteria are able to grow during shelf life. A total of 58 samples from butchers' shops, restaurants, sandwich shops, and supermarkets were collected. These samples were analyzed using 16S rDNA metagenetics, a classical microbiological technique, and quantitative real-time PCR (qPCR) targeting the Lactobacillus genus. Samples were analyzed at the beginning and at the end of their shelf life, except for those from restaurants and sandwich shops, which were analyzed only on the purchase date. Metagenetic analysis identified up to 180 bacterial species and 90 genera in some samples. But only seven bacterial species were predominant in the samples, depending on the source: Brochothrix thermosphacta, Lactobacillus algidus, Lactococcus piscium, Leuconostoc gelidum, Photobacterium kishitani, Pseudomonas spp., and Xanthomonas oryzae. With this work, an alternative method is proposed to evaluate the total flora in food samples based on the number of reads from metagenetic analysis and the results of qPCR. The degree of underestimation of aerobic plate counts at 30°C estimated with the classical microbiology method was demonstrated in comparison with the proposed culture-independent method. Compared with culture-based methods, metagenetic analysis combined with qPCR targeting Lactobacillus provides valuable information for characterizing the bacterial flora of raw meat. PMID:26818982

  1. Counting supersymmetric branes

    NASA Astrophysics Data System (ADS)

    Kleinschmidt, Axel

    2011-10-01

    Maximal supergravity solutions are revisited and classified, with particular emphasis on objects of co-dimension at most two. This class of solutions includes branes whose tension scales with xxxx. We present a group theory derivation of the counting of these objects based on the corresponding tensor hierarchies derived from E 11 and discrete T- and U-duality transformations. This provides a rationale for the wrapping rules that were recently discussed for σ ≤ 3 in the literature and extends them. Explicit supergravity solutions that give rise to co-dimension two branes are constructed and analysed.

  2. Contribution of particle counting in assessment of exposure to airborne microorganisms

    NASA Astrophysics Data System (ADS)

    Parat, Sylvie; Perdrix, Alain; Mann, Sylvie; Baconnier, Pierre

    The aim of the study was to determine the relationship between airborne bacterial concentrations and particle counts measured simultaneously at different sites. Andersen single stage viable particle samplers were used for microbial measurements while a Laser particle counter gave the cumulated counts of particles larger than 0.5 μm diameter. The first phase of the study was performed in two experimental rooms where the basic level of microbial contamination was low. Peaks of concentrations were generated by human activity and both bacterial and particle counts were monitored over 1 h. In the second phase, measurements were run for several days in three different buildings normally occupied. Natural variations of bacterial and particle counts were monitored: microbial measurements were performed each hour while particle counts were started with a 10 min frequency. Statistics revealed strong positive correlations between bacterial and particle counts in four sites out of five. Analyses of covariance used to compare the regression lines obtained in each area showed that except for two natural sites, the regression lines were significantly different, indicating that no absolute relationship can be established between the two parameters. Therefore, particle counting should, of course, not take the place of microorganism measurements, but combining particle counting with bioaerosols measurements may allow detection of rapid variations instantaneously and indicate further microbial measurements. This strategy should improve the assessment of people"s real exposure to airborne microorganisms.

  3. Temperature and bacterial profile of post chill poultry carcasses stored in processing combo held at room temperature.

    PubMed

    Handley, John A; Hanning, Irene; Ricke, Steven C; Johnson, Michael G; Jones, Frank T; Apple, Robert O

    2010-10-01

    Post chill whole poultry carcasses from a commercial processing plant were stored in a processing combo at room temperature (70 °F/21 °C) for 54 h to mimic the scenario of temperature abuse before further processing. Temperature data were collected in 1-min intervals and averaged each hour by 9 temperature data loggers. Two linear regressions were developed for the combo and internal breast temperature and slopes were nearly identical. Microbial data was collected by performing whole bird carcass rinses that were enumerated for aerobic plate count (APC), Enterobacteriaceae, Escherichia coli, and total coliform. Samples were collected from the chiller chute at time zero for initial bacterial counts. Carcass sampling continued once the internal breast temperature achieved 45 °F (7 °C 10 h) and continued every 2 h until the final internal breast temperature was 63 °F (17 °C 54 h). Linear regressions were developed for the first 26 h, which exhibited no statistically significant growth except for Enterobacteriaceae. A 2nd linear regression (28 to 54 h) exhibited significant growth for all analyses. Overall, APC increased from a log(10) colony forming unit (CFU)/mL count of 2.86 to 7.02, Enterobacteriaceae increased from 0.66 to 6.64, coliform increased from 0.72 to 4.81, and E. coli increased from 0.53 to 4.45. Denaturing gradient gel electrophoresis was performed to detect changes in the bacterial populations, which indicated 95% similarity within sampled groups, but the overall percent similarity among samples collected over 54 h was 8%. From the data, microbial growth demonstrates a period of 26 h for minimal growth; therefore, the product could be further processed rather than designated as waste. PMID:21535507

  4. Fit women are not able to use the whole aerobic capacity during aerobic dance.

    PubMed

    Edvardsen, Elisabeth; Ingjer, Frank; Bø, Kari

    2011-12-01

    Edvardsen, E, Ingjer, F, and Bø, K. Fit women are not able to use the whole aerobic capacity during aerobic dance. J Strength Cond Res 25(12): 3479-3485, 2011-This study compared the aerobic capacity during maximal aerobic dance and treadmill running in fit women. Thirteen well-trained female aerobic dance instructors aged 30 ± 8.17 years (mean ± SD) exercised to exhaustion by running on a treadmill for measurement of maximal oxygen uptake (VO(2)max) and peak heart rate (HRpeak). Additionally, all subjects performed aerobic dancing until exhaustion after a choreographed videotaped routine trying to reach the same HRpeak as during maximal running. The p value for statistical significance between running and aerobic dance was set to ≤0.05. The results (mean ± SD) showed a lower VO(2)max in aerobic dance (52.2 ± 4.02 ml·kg·min) compared with treadmill running (55.9 ± 5.03 ml·kg·min) (p = 0.0003). Further, the mean ± SD HRpeak was 182 ± 9.15 b·min in aerobic dance and 192 ± 9.62 b·min in treadmill running, giving no difference in oxygen pulse between the 2 exercise forms (p = 0.32). There was no difference in peak ventilation (aerobic dance: 108 ± 10.81 L·min vs. running: 113 ± 11.49 L·min). In conclusion, aerobic dance does not seem to be able to use the whole aerobic capacity as in running. For well endurance-trained women, this may result in a lower total workload at maximal intensities. Aerobic dance may therefore not be as suitable as running during maximal intensities in well-trained females. PMID:22080322

  5. Bacterial adenosine triphosphate as a measure of urinary tract infection

    NASA Technical Reports Server (NTRS)

    Chappelle, E. W.; Picciolo, G. L.

    1971-01-01

    Procedure detects and counts bacteria present in urine samples. Method also determines bacterial levels in other aqueous body fluids including lymph fluid, plasma, blood, spinal fluid, saliva and mucous.

  6. High background photon counting lidar

    NASA Technical Reports Server (NTRS)

    Lentz, W. J.

    1992-01-01

    Photon counting with lidar returns is usually limited to low light levels, while wide dynamic range is achieved by counting for long times. The broad emission spectrum of inexpensive high-power semiconductor lasers makes receiver filters pass too much background light for traditional photon counting in daylight. Very high speed photon counting is possible, however, at more than 500 MHz which allows the construction of eyesafe lidar operating in the presence of bright clouds. Detector improvements are possible to count to 20 GHz producing a single shot dynamic range of ten decades.

  7. Ecology of aerobic anoxygenic phototrophs in aquatic environments.

    PubMed

    Koblížek, Michal

    2015-11-01

    Recognition of the environmental role of photoheterotrophic bacteria has been one of the main themes of aquatic microbiology over the last 15 years. Aside from cyanobacteria and proteorhodopsin-containing bacteria, aerobic anoxygenic phototrophic (AAP) bacteria are the third most numerous group of phototrophic prokaryotes in the ocean. This functional group represents a diverse assembly of species which taxonomically belong to various subgroups of Alpha-, Beta- and Gammaproteobacteria. AAP bacteria are facultative photoheterotrophs which use bacteriochlorophyll-containing reaction centers to harvest light energy. The light-derived energy increases their bacterial growth efficiency, which provides a competitive advantage over heterotrophic species. Thanks to their enzymatic machinery AAP bacteria are active, rapidly growing organisms which contribute significantly to the recycling of organic matter. This chapter summarizes the current knowledge of the ecology of AAP bacteria in aquatic environments, implying their specific role in the microbial loop. PMID:26139241

  8. Heterotrophic plate count methodology in the United States.

    PubMed

    Reasoner, Donald J

    2004-05-01

    In the United States (US), the history of bacterial plate counting (BPC) methods used for water can be traced largely through Standard Methods for the Examination of Water and Wastewater (Standard Methods). The bacterial count method has evolved from the original Standard Methods (1st edition, 1905) plate count which used nutrient gelatin and incubation at 20 degrees C for 48 h, to the HPC method options in the latest edition of Standard Methods that provide greater flexibility of application, depending on the data needs of the water analyst. The use of agar-agar as a gelling agent, replacing gelatin, allowed the use of higher incubation temperatures and resulted in the "body temperature count" (37 degrees C) found in the 3rd through the 8th edition of Standard Methods. The change from 37 degrees C incubation to 35+/-0.5 degrees C accommodated laboratories that did both milk and water analyses. By using a single temperature, fewer incubators were needed. The term "standard plate count" (SPC) first appeared in 1960 (11th edition) along with plate count agar. Incubation at 20 degrees C for the plate count was dropped from the 13th to 15th editions and few changes were made in the SPC method from the 11th edition through the 13th editions. Plate count analysis of bottled waters was included in the 14th edition (1975), calling for incubation at 35+/-0.5 degrees C for 72+/-4 h. Perhaps the most significant changes in plate count methods occurred with the 16th edition (1985). The term heterotrophic plate count replaced the standard plate count, and the spread plate (SP) and membrane filter (MF) methods were added along with new media for pour and spread plates (R2A agar and NWRI agar, both low nutrient) and for the membrane filter method (mHPC medium). The use of low nutrient media, lower incubation temperature, and longer incubation times, results in higher plate count results for most water samples. The options currently available, including low and high nutrient media

  9. The Energetics of Aerobic versus Anaerobic Respiration.

    ERIC Educational Resources Information Center

    Champion, Timothy D.; Schwenz, Richard W.

    1990-01-01

    Background information, laboratory procedures, and a discussion of the results of an experiment designed to investigate the difference in energy gained from the aerobic and anaerobic oxidation of glucose are presented. Sample experimental and calculated data are included. (CW)

  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 Dance for Children: Resources and Recommendations.

    ERIC Educational Resources Information Center

    Wood, Denise A.

    1986-01-01

    Aerobic dance classes may be safe for older children, but are inappropriate for children in the fourth grade and under. Programs for these children should emphasize creativity. Resources for program development are given. (MT)

  12. 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)

  13. Aerobic dynamic feeding as a strategy for in situ accumulation of polyhydroxyalkanoate in aerobic granules.

    PubMed

    Gobi, K; Vadivelu, V M

    2014-06-01

    Aerobic dynamic feeding (ADF) strategy was applied in sequencing batch reactor (SBR) to accumulate polyhydroxyalkanoate (PHA) in aerobic granules. The aerobic granules were able to remove 90% of the COD from palm oil mill effluent (POME). The volatile fatty acids (VFAs) in the POME are the sole source of the PHA accumulation. In this work, 100% removal of propionic and butyric acids in the POME were observed. The highest amount of PHA produced in aerobic granules was 0.6833mgPHA/mgbiomass. The PHA formed was identified as a P (hydroxybutyrate-co-hydroxyvalerate) P (HB-co-HV). PMID:24725384

  14. Physiological responses during aerobic dance of individuals grouped by aerobic capacity and dance experience.

    PubMed

    Thomsen, D; Ballor, D L

    1991-03-01

    This study examined the effects of aerobic capacity (peak oxygen uptake) and aerobic dance experience on the physiological responses to an aerobic dance routine. The heart rate (HR) and VO2 responses to three levels (intensities) of aerobic dance were measured in 27 women. Experienced aerobic dancers (AD) (mean peak VO2 = 42 ml.kg-1.min-1) were compared to subjects with limited aerobic dance experience of high (HI) (peak VO2 greater than 35 ml.kg-1.min-1) and low (LO) (peak VO2 less than 35 ml.kg-1.min-1) aerobic capacities. The results indicated the LO group exercised at a higher percentage of peak heart rate and peak VO2 at all three dance levels than did either the HI or AD groups (HI = AD). Design of aerobic dance routines must consider the exercise tolerance of the intended audience. In mixed groups, individuals with low aerobic capacities should be shown how and encouraged to modify the activity to reduce the level of exertion. PMID:2028095

  15. Enrichment of anodic biofilm inoculated with anaerobic or aerobic sludge in single chambered air-cathode microbial fuel cells.

    PubMed

    Gao, Chongyang; Wang, Aijie; Wu, Wei-Min; Yin, Yalin; Zhao, Yang-Guo

    2014-09-01

    Aerobic sludge after anaerobic pretreatment and anaerobic sludge were separately used as inoculum to start up air-cathode single-chamber MFCs. Aerobic sludge-inoculated MFCs arrived at 0.27 V with a maximum power density of 5.79 W m(-3), while anaerobic sludge-inoculated MFCs reached 0.21 V with 3.66 W m(-3). Microbial analysis with DGGE profiling and high-throughput sequencing indicated that aerobic sludge contained more diverse bacterial populations than anaerobic sludge. Nitrospira species dominated in aerobic sludge, while anaerobic sludge was dominated by Desulfurella and Acidithiobacillus species. Microbial community structure and composition in anodic biofilms enriched, respectively from aerobic and anaerobic sludges tended gradually to be similar. Potentially exoelectrogenic Geobacter and Anaeromusa species, biofilm-forming Zoogloea and Acinetobacter species were abundant in both anodic biofilms. This study indicated that aerobic sludge performed better for MFCs startup, and the enrichment of anodic microbial consortium with different inocula but same substrate resulted in uniformity of functional microbial communities. PMID:24973773

  16. Bacterial Immunity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A variety of bacterial agents reside in and around the environment that can cause illness and death in a poultry flock. Many cause disseminated disease while others exert more local effects such as the respiratory or gastrointestinal tract. The host, for our current purposes the laying hen, has de...

  17. Some special problems in the determination of viable counts of groundwater microorganisms.

    PubMed

    Hirsch, P; Rades-Rohkohl, E

    1988-07-01

    Factors affecting viable cell counts in groundwater or sediments were studied with samples from the Segeberg Forest test area in northern Germany. There was very little variation in results with the season (April, August, November) or depth of sampling; generally there were 10(3)-10(4) aerobic cells per ml or g sediment. Long incubation times resulted in higher cell counts; groundwater samples required 4-5 weeks, and sediment extracts had to be cultured for 7 weeks. Total cell counts in sediment were 10(2)-10(4) cell/g higher than viable cell counts of aerobes. This was explained partly by the additional presence of anaerobes and partly by the observation that some morphotypes may not have grown under our conditions. Viable cell counts were not influenced by cell extraction from the sediment with either Na-pyrophosphate or groundwater extracts. However, iron-precipitating or manganese-oxidizing bacteria were better extracted with sterile groundwater. The microflora of wells was more numerous than that of the free aquifer; consequently it was better to pump off all well water before aquifer water was sampled. The diameter of the well was also important; thinner tubes had higher cell counts than those with wider diameter. For sampling, wells should be at least 1 year old, since young wells contain higher numbers of microorganisms due to underground disturbances from the drilling. Turbid water samples could be clarified by filtration, but this reduced the viable counts by 1-2 orders of magnitude. Two different media inoculated with a sample dilution resulted in the same cell counts, but their microbial diversity was different. Storage of groundwater samples before processing resulted in up to 17-fold increases in cell counts and loss of diversity in the first 24 hours. Cell numbers decreased slowly during longer storage. PMID:24201536

  18. Microbial diversity differences within aerobic granular sludge and activated sludge flocs.

    PubMed

    Winkler, M-K H; Kleerebezem, R; de Bruin, L M M; Verheijen, P J T; Abbas, B; Habermacher, J; van Loosdrecht, M C M

    2013-08-01

    In this study, we investigated during 400 days the microbial community variations as observed from 16S DNA gene DGGE banding patterns from an aerobic granular sludge pilot plant as well as the from a full-scale activated sludge treatment plant in Epe, the Netherlands. Both plants obtained the same wastewater and had the same relative hydraulic variations and run stable over time. For the total bacterial population, a similarity analysis was conducted showing that the community composition of both sludge types was very dissimilar. Despite this difference, general bacterial population of both systems had on average comparable species richness, entropy, and evenness, suggesting that different bacteria were sharing the same functionality. Moreover, multi-dimensional scaling analysis revealed that the microbial populations of the flocculent sludge system moved closely around the initial population, whereas the bacterial population in the aerobic granular sludge moved away from its initial population representing a permanent change. In addition, the ammonium-oxidizing community of both sludge systems was studied in detail showing more unevenness than the general bacterial community. Nitrosomonas was the dominant AOB in flocculent sludge, whereas in granular sludge, Nitrosomonas and Nitrosospira were present in equal amounts. A correlation analysis of process data and microbial data from DGGE gels showed that the microbial diversity shift in ammonium-oxidizing bacteria clearly correlated with fluctuations in temperature. PMID:23064482

  19. Aerobic exercise protects retinal function and structure from light-induced retinal degeneration.

    PubMed

    Lawson, Eric C; Han, Moon K; Sellers, Jana T; Chrenek, Micah A; Hanif, Adam; Gogniat, Marissa A; Boatright, Jeffrey H; Pardue, Machelle T

    2014-02-12

    Aerobic exercise is a common intervention for rehabilitation of motor, and more recently, cognitive function (Intlekofer and Cotman, 2013; Wood et al., 2012). While the underlying mechanisms are complex, BDNF may mediate much of the beneficial effects of exercise to these neurons (Ploughman et al., 2007; Griffin et al., 2011; Real et al., 2013). We studied the effects of aerobic exercise on retinal neurons undergoing degeneration. We exercised wild-type BALB/c mice on a treadmill (10 m/min for 1 h) for 5 d/week or placed control mice on static treadmills. After 2 weeks of exercise, mice were exposed to either toxic bright light (10,000 lux) for 4 h to induce photoreceptor degeneration or maintenance dim light (25 lux). Bright light caused 75% loss of both retinal function and photoreceptor numbers. However, exercised mice exposed to bright light had 2 times greater retinal function and photoreceptor nuclei than inactive mice exposed to bright light. In addition, exercise increased retinal BDNF protein levels by 20% compared with inactive mice. Systemic injections of a BDNF tropomyosin-receptor-kinase (TrkB) receptor antagonist reduced retinal function and photoreceptor nuclei counts in exercised mice to inactive levels, effectively blocking the protective effects seen with aerobic exercise. The data suggest that aerobic exercise is neuroprotective for retinal degeneration and that this effect is mediated by BDNF signaling. PMID:24523530

  20. Effects of a Chlorhexidine Gluconate-Containing Mouthwash on the Vitality and Antimicrobial Susceptibility of In Vitro Oral Bacterial Ecosystems

    PubMed Central

    McBain, Andrew J.; Bartolo, Robert G.; Catrenich, Carl E.; Charbonneau, Duane; Ledder, Ruth G.; Gilbert, Peter

    2003-01-01

    Oral bacterial microcosms, established using saliva inocula from three individuals, were maintained under a feast-famine regime within constant-depth film fermenters. Steady-state communities were exposed four times daily, postfeeding, to a chlorhexidine (CHX) gluconate-containing mouthwash (CHXM) diluted to 0.06% (wt/vol) antimicrobial content. The microcosms were characterized by heterotrophic plate counts and PCR-denaturing gradient gel electrophoresis (DGGE). CHXM caused significant decreases in both total anaerobe and total aerobe/facultative anaerobe counts (P < 0.05), together with lesser decreases in gram-negative anaerobes. The degree of streptococcal and actinomycete inhibition varied considerably among individuals. DGGE showed that CHXM exposure caused considerable decreases in microbial diversity, including marked reductions in Prevotella sp. and Selenomonas infelix. Pure-culture studies of 10 oral bacteria (eight genera) showed that Actinomyces naeslundii, Veillonella dispar, Prevotella nigrescens, and the streptococci were highly susceptible to CHX, while Lactobacillus rhamnosus, Fusobacterium nucleatum, and Neisseria subflava were the least susceptible. Determination of the MICs of triclosan, CHX, erythromycin, penicillin V, vancomycin, and metronidazole for microcosm isolates, before and after 5 days of CHXM exposure, showed that CHXM exposure altered the distribution of isolates toward those that were less susceptible to CHX (P < 0.05). Changes in susceptibility distributions for the other test agents were not statistically significant. In conclusion, population changes in plaque microcosms following repeated exposure to CHXM represented an inhibition of the most susceptible flora with a clonal expansion of less susceptible species. PMID:12902270

  1. Effects of a chlorhexidine gluconate-containing mouthwash on the vitality and antimicrobial susceptibility of in vitro oral bacterial ecosystems.

    PubMed

    McBain, Andrew J; Bartolo, Robert G; Catrenich, Carl E; Charbonneau, Duane; Ledder, Ruth G; Gilbert, Peter

    2003-08-01

    Oral bacterial microcosms, established using saliva inocula from three individuals, were maintained under a feast-famine regime within constant-depth film fermenters. Steady-state communities were exposed four times daily, postfeeding, to a chlorhexidine (CHX) gluconate-containing mouthwash (CHXM) diluted to 0.06% (wt/vol) antimicrobial content. The microcosms were characterized by heterotrophic plate counts and PCR-denaturing gradient gel electrophoresis (DGGE). CHXM caused significant decreases in both total anaerobe and total aerobe/facultative anaerobe counts (P < 0.05), together with lesser decreases in gram-negative anaerobes. The degree of streptococcal and actinomycete inhibition varied considerably among individuals. DGGE showed that CHXM exposure caused considerable decreases in microbial diversity, including marked reductions in Prevotella sp. and Selenomonas infelix. Pure-culture studies of 10 oral bacteria (eight genera) showed that Actinomyces naeslundii, Veillonella dispar, Prevotella nigrescens, and the streptococci were highly susceptible to CHX, while Lactobacillus rhamnosus, Fusobacterium nucleatum, and Neisseria subflava were the least susceptible. Determination of the MICs of triclosan, CHX, erythromycin, penicillin V, vancomycin, and metronidazole for microcosm isolates, before and after 5 days of CHXM exposure, showed that CHXM exposure altered the distribution of isolates toward those that were less susceptible to CHX (P < 0.05). Changes in susceptibility distributions for the other test agents were not statistically significant. In conclusion, population changes in plaque microcosms following repeated exposure to CHXM represented an inhibition of the most susceptible flora with a clonal expansion of less susceptible species. PMID:12902270

  2. Making environmental DNA count.

    PubMed

    Kelly, Ryan P

    2016-01-01

    The arc of reception for a new technology or method--like the reception of new information itself--can pass through predictable stages, with audiences' responses evolving from 'I don't believe it', through 'well, maybe' to 'yes, everyone knows that' to, finally, 'old news'. The idea that one can sample a volume of water, sequence DNA out of it, and report what species are living nearby has experienced roughly this series of responses among biologists, beginning with the microbial biologists who developed genetic techniques to reveal the unseen microbiome. 'Macrobial' biologists and ecologists--those accustomed to dealing with species they can see and count--have been slower to adopt such molecular survey techniques, in part because of the uncertain relationship between the number of recovered DNA sequences and the abundance of whole organisms in the sampled environment. In this issue of Molecular Ecology Resources, Evans et al. (2015) quantify this relationship for a suite of nine vertebrate species consisting of eight fish and one amphibian. Having detected all of the species present with a molecular toolbox of six primer sets, they consistently find DNA abundances are associated with species' biomasses. The strength and slope of this association vary for each species and each primer set--further evidence that there is no universal parameter linking recovered DNA to species abundance--but Evans and colleagues take a significant step towards being able to answer the next question audiences tend to ask: 'Yes, but how many are there?' PMID:26768195

  3. Compton suppression gamma-counting: The effect of count rate

    USGS Publications Warehouse

    Millard, H.T., Jr.

    1984-01-01

    Past research has shown that anti-coincidence shielded Ge(Li) spectrometers enhanced the signal-to-background ratios for gamma-photopeaks, which are situated on high Compton backgrounds. Ordinarily, an anti- or non-coincidence spectrum (A) and a coincidence spectrum (C) are collected simultaneously with these systems. To be useful in neutron activation analysis (NAA), the fractions of the photopeak counts routed to the two spectra must be constant from sample to sample to variations must be corrected quantitatively. Most Compton suppression counting has been done at low count rate, but in NAA applications, count rates may be much higher. To operate over the wider dynamic range, the effect of count rate on the ratio of the photopeak counts in the two spectra (A/C) was studied. It was found that as the count rate increases, A/C decreases for gammas not coincident with other gammas from the same decay. For gammas coincident with other gammas, A/C increases to a maximum and then decreases. These results suggest that calibration curves are required to correct photopeak areas so quantitative data can be obtained at higher count rates. ?? 1984.

  4. Taxonomy of Aerobic Marine Eubacteria

    PubMed Central

    Baumann, Linda; Baumann, Paul; Mandel, M.; Allen, Richard D.

    1972-01-01

    Two hundred and eighteen strains of nonfermentative marine bacteria were submitted to an extensive morphological, physiological, and nutritional characterization. All the strains were gram-negative, straight or curved rods which were motile by means of polar or peritrichous flagella. A wide variety of organic substrates served as sole sources of carbon and energy. The strains differed extensively in their nutritional versatility, being able to utilize from 11 to 85 carbon compounds. Some strains had an extracellular amylase, gelatinase, lipase, or chitinase and were able to utilize n-hexadecane and to denitrify. None of the strains had a yellow, cell-associated pigment or a constitutive arginine dihydrolase system, nor were they able to hydrolyze cellulose or agar. The results of the physiological and nutritional characterization were submitted to a numerical analysis which clustered the strains into 22 groups on the basis of phenotypic similarities. The majority of these groups were separable by a large number of unrelated phenotypic traits. Analysis of the moles per cent guanine plus cytosine (GC) content in the deoxyribonucleic acid of representative strains indicated that the peritrichously flagellated groups had a GC content of 53.7 to 67.8 moles%; polarly flagellated strains had a GC content of 30.5 to 64.7 moles%. The peritrichously flagellated groups were assigned to the genus Alcaligenes. The polarly flagellated groups, which had a GC content of 43.2 to 48.0 moles%, were placed into a newly created genus, Alteromonas; groups which had a GC content of 57.8 to 64.7 moles% were placed into the genus Pseudomonas; and the remaining groups were left unassigned. Twelve groups were given the following designations: Alteromonas communis, A. vaga, A. macleodii, A. marinopraesens, Pseudomonas doudoroffi, P. marina, P. nautica, Alcaligenes pacificus, A. cupidus, A. venustus, and A. aestus. The problems of assigning species of aerobic marine bacteria to genera are

  5. Taxonomy of aerobic marine eubacteria.

    PubMed

    Baumann, L; Baumann, P; Mandel, M; Allen, R D

    1972-04-01

    Two hundred and eighteen strains of nonfermentative marine bacteria were submitted to an extensive morphological, physiological, and nutritional characterization. All the strains were gram-negative, straight or curved rods which were motile by means of polar or peritrichous flagella. A wide variety of organic substrates served as sole sources of carbon and energy. The strains differed extensively in their nutritional versatility, being able to utilize from 11 to 85 carbon compounds. Some strains had an extracellular amylase, gelatinase, lipase, or chitinase and were able to utilize n-hexadecane and to denitrify. None of the strains had a yellow, cell-associated pigment or a constitutive arginine dihydrolase system, nor were they able to hydrolyze cellulose or agar. The results of the physiological and nutritional characterization were submitted to a numerical analysis which clustered the strains into 22 groups on the basis of phenotypic similarities. The majority of these groups were separable by a large number of unrelated phenotypic traits. Analysis of the moles per cent guanine plus cytosine (GC) content in the deoxyribonucleic acid of representative strains indicated that the peritrichously flagellated groups had a GC content of 53.7 to 67.8 moles%; polarly flagellated strains had a GC content of 30.5 to 64.7 moles%. The peritrichously flagellated groups were assigned to the genus Alcaligenes. The polarly flagellated groups, which had a GC content of 43.2 to 48.0 moles%, were placed into a newly created genus, Alteromonas; groups which had a GC content of 57.8 to 64.7 moles% were placed into the genus Pseudomonas; and the remaining groups were left unassigned. Twelve groups were given the following designations: Alteromonas communis, A. vaga, A. macleodii, A. marinopraesens, Pseudomonas doudoroffi, P. marina, P. nautica, Alcaligenes pacificus, A. cupidus, A. venustus, and A. aestus. The problems of assigning species of aerobic marine bacteria to genera are

  6. 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…

  7. Bioaugmentation and enhanced formation of microbial granules used in aerobic wastewater treatment.

    PubMed

    Ivanov, Volodymyr; Wang, Xiao-Hui; Tay, Stephen Tiong-Lee; Tay, Joo-Hwa

    2006-04-01

    Microbial aggregates of an aerobic granular sludge can be used for the treatment of industrial or municipal wastewater, but their formation from a microbial activated sludge requires several weeks. Therefore, the aim of this research was the selection of microbial cultures to shorten the granule-forming period from several weeks to a few days. An enrichment culture with the ability to accelerate granulation was obtained by repeating the selection and batch cultivation of fast-settling microbial aggregates isolated from the aerobic granular sludge. Bacterial cultures of Klebsiella pneumoniae strain B and Pseudomonas veronii strain F, with self-aggregation indexes of 65 and 51%, respectively, and a coaggregation index of 58%, were isolated from the enrichment culture. A mixture of these strains with the activated sludge was used as an inoculum in an experimental sequencing batch reactor to start up an aerobic granulation process. Aerobic granules with a mean diameter of 446+/-76 microm were formed in an experiment after 8 days of cultivation, but microbial granules were absent in controls. Considering biosafety issues, K. pneumoniae strain B was excluded from further studies, but P. veronii strain F was selected for larger-scale testing. PMID:16091930

  8. Enteral nutrient solutions. Limiting bacterial growth.

    PubMed

    Paauw, J D; Fagerman, K E; McCamish, M A; Dean, R E

    1984-06-01

    Bacterial contamination of enteral nutrient solutions ( ENS ) in FFcess of food product standards is known to occur in the hospital setting. The large amounts of bacteria often given with ENS have been shown to create a reservoir for nosocomial infections, and nonpathogenic bacteria have been implicated. Patient tolerance is dependent on immune status and the bacterial load delivered to the gut. The purpose of this study was to evaluate the bacterial growth-sustaining properties of various ENS and to devise methods to limit bacterial growth. Five commercial products were prepared under sterile conditions. After inoculation with approximately 5 X 10(3) organisms/cm3 of Enterobacter cloacae, each solution was hung at room temperature for 24 hours with samples drawn at fixed intervals and plated for bacterial counts. Bacterial growth rates in Ensure, Travasorb , and Vital were markedly higher than those in Precision and Vivonex. Vivonex was noted to contain potassium sorbate (KS) used as a fungistatic agent. Recent studies have identified KS as a broad-spectrum bacteriostatic food preservative that is federally approved for this use. KS (0.03%) was added to Travasorb inoculated with 5 X 10(3) organisms/cm(3) of E. cloacae. The bacterial growth rate was reduced by 75 per cent, and the final count of 2-3 X 10(4) organisms/ml was within the federally regulated limit for milk. This study suggests that initial inoculum, growth rate, and hang time can be altered to provide a significant reduction in final bacterial counts in ENS . PMID:6428286

  9. Biodegradation of tributyl phosphate, an organosphate triester, by aerobic granular biofilms.

    PubMed

    Nancharaiah, Y V; Kiran Kumar Reddy, G; Krishna Mohan, T V; Venugopalan, V P

    2015-01-01

    Tributyl phosphate (TBP) is commercially used in large volumes for reprocessing of spent nuclear fuel. TBP is a very stable compound and persistent in natural environments and it is not removed in conventional wastewater treatment plants. In this study, cultivation of aerobic granular biofilms in a sequencing batch reactor was investigated for efficient biodegradation of TBP. Enrichment of TBP-degrading strains resulted in efficient degradation of TBP as sole carbon or along with acetate. Complete biodegradation of 2mM of TBP was achieved within 5h with a degradation rate of 0.4 μmol mL(-1) h(-1). TBP biodegradation was accompanied by release of inorganic phosphate in stoichiometric amounts. n-Butanol, hydrolysed product of TBP was rapidly biodegraded. But, dibutyl phosphate, a putative intermediate of TBP degradation was only partially degraded pointing to an alternative degradation pathway. Phosphatase activity was 22- and 7.5-fold higher in TBP-degrading biofilms as compared to bioflocs and acetate-fed aerobic granules. Community analysis by terminal restriction length polymorphism revealed presence of 30 different bacterial strains. Seven bacterial stains, including Sphingobium sp. a known TBP degrader were isolated. The results show that aerobic granular biofilms are promising for treatment of TBP-bearing wastes or ex situ bioremediation of TBP-contaminated sites. PMID:25464313

  10. Young Children Counting at Home

    ERIC Educational Resources Information Center

    Griffiths, Rose

    2007-01-01

    Learning to count is something that most children start to do by the time they are about two, and parents know from first-hand experience that family members play a big part in helping with this complex process. In this article, the author describes a project involving families sharing effective counting activities. The project called "Getting…

  11. Preschooler's Counting in Peer Interaction.

    ERIC Educational Resources Information Center

    Curtis, Reagan P.

    For this experiment, part of a larger study on preschoolers' counting competence, 3-, 4-, and 5-year-olds played a counting game with their peers after becoming familiar with the game during structured interviews with an adult. It was expected that the symmetrical nature of peer interaction would allow children to display quantitative knowledge in…

  12. Bacterial oxidation of methyl bromide in fumigated agricultural soils

    USGS Publications Warehouse

    Miller, L.G.; Connell, T.L.; Guidetti, J.R.; Oremland, R.S.

    1997-01-01

    The oxidation of [14C]methyl bromide ([14C]MeBr) to 14CO2 was measured in field experiments with soils collected from two strawberry plots fumigated with mixtures of MeBr and chloropicrin (CCI3NO2). Although these fumigants are considered potent biocides, we found that the highest rates of MeBr oxidation occurred 1 to 2 days after injection when the fields were tarped, rather than before or several days after injection. No oxidation of MeBr occurred in heat-killed soils, indicating that microbes were the causative agents of the oxidation. Degradation of MeBr by chemical and/or biological processes accounted for 20 to 50% of the loss of MeBr during fumigation, with evasion to the atmosphere inferred to comprise the remainder. In laboratory incubations, complete removal of [14C]MeBr occurred within a few days, with 47 to 67% of the added MeBr oxidized to 14CO2 and the remainder of counts associated with the solid phase. Chloropicrin inhibited the oxidation of MeBr, implying that use of this substance constrains the extent of microbial degradation of MeBr during fumigation. Oxidation was by direct bacterial attack of MeBr and not of methanol, a product of the chemical hydrolysis of MeBr. Neither nitrifying nor methane-oxidizing bacteria were sufficiently active in these soils to account for the observed oxidation of MeBr, nor could the microbial degradation of MeBr be linked to cooxidation with exogenously supplied electron donors. However, repeated addition of MeBr to live soils resulted in higher rates of its removal, suggesting that soil bacteria used MeBr as an electron donor for growth. To support this interpretation, we isolated a gram-negative, aerobic bacterium from these soils which grew with MeBr as a sole source of carbon and energy.

  13. Controlling the catalytic aerobic oxidation of phenols.

    PubMed

    Esguerra, Kenneth Virgel N; Fall, Yacoub; Petitjean, Laurène; Lumb, Jean-Philip

    2014-05-28

    The oxidation of phenols is the subject of extensive investigation, but there are few catalytic aerobic examples that are chemo- and regioselective. Here we describe conditions for the ortho-oxygenation or oxidative coupling of phenols under copper (Cu)-catalyzed aerobic conditions that give rise to ortho-quinones, biphenols or benzoxepines. We demonstrate that each product class can be accessed selectively by the appropriate choice of Cu(I) salt, amine ligand, desiccant and reaction temperature. In addition, we evaluate the effects of substituents on the phenol and demonstrate their influence on selectivity between ortho-oxygenation and oxidative coupling pathways. These results create an important precedent of catalyst control in the catalytic aerobic oxidation of phenols and set the stage for future development of catalytic systems and mechanistic investigations. PMID:24784319

  14. [Anaerobic-aerobic infection in acute appendicitis].

    PubMed

    Mamchich, V I; Ulitovskiĭ, I V; Savich, E I; Znamenskiĭ, V A; Beliaeva, O A

    1998-01-01

    362 patients with acute appendicitis (AA) were examined. For microbiological diagnosis of aerobic and anaerobic nonclostridial microflora we used complex accelerated methods (including evaluation of gram-negative microorganisms in comparison with tinctorial-fermentative method of differential staining according to oxygen sensitivity of catalasopositive together with aerobic and cathalasonegative anaerobic microorganisms) as well as complete bacteriologic examination with determination of sensitivity of the above microorganism to antimicrobial remedies. High rate of aerobic-anaerobic microbial associations and substantial identity of microflora from appendicis and exudate from abdominal cavity was revealed, which evidenced the leading role of endogenous microorganisms in etiology and pathogenesis of AA and peritonitis i. e. autoinfection. In patients with destructive forms of AA, complicated by peritonitis it is recommended to use the accelerated method of examination of pathologic material as well as the complete scheme of examination with the identification of the isolated microorganisms and the correction of antibiotic treatment. PMID:9511291

  15. Drying and recovery of aerobic granules.

    PubMed

    Hu, Jianjun; Zhang, Quanguo; Chen, Yu-You; Lee, Duu-Jong

    2016-10-01

    To dehydrate aerobic granules to bone-dry form was proposed as a promising option for long-term storage of aerobic granules. This study cultivated aerobic granules with high proteins/polysaccharide ratio and then dried these granules using seven protocols: drying at 37°C, 60°C, 4°C, under sunlight, in dark, in a flowing air stream or in concentrated acetone solutions. All dried granules experienced volume shrinkage of over 80% without major structural breakdown. After three recovery batches, although with loss of part of the volatile suspended solids, all dried granules were restored most of their original size and organic matter degradation capabilities. The strains that can survive over the drying and storage periods were also identified. Once the granules were dried, they can be stored over long period of time, with minimal impact yielded by the applied drying protocols. PMID:27392096

  16. Organic micropollutants in aerobic and anaerobic membrane bioreactors: Changes in microbial communities and gene expression.

    PubMed

    Harb, Moustapha; Wei, Chun-Hai; Wang, Nan; Amy, Gary; Hong, Pei-Ying

    2016-10-01

    Organic micro-pollutants (OMPs) are contaminants of emerging concern in wastewater treatment due to the risk of their proliferation into the environment, but their impact on the biological treatment process is not well understood. The purpose of this study is to examine the effects of the presence of OMPs on the core microbial populations of wastewater treatment. Two nanofiltration-coupled membrane bioreactors (aerobic and anaerobic) were subjected to the same operating conditions while treating synthetic municipal wastewater spiked with OMPs. Microbial community dynamics, gene expression levels, and antibiotic resistance genes were analyzed using molecular-based approaches. Results showed that presence of OMPs in the wastewater feed had a clear effect on keystone bacterial populations in both the aerobic and anaerobic sludge while also significantly impacting biodegradation-associated gene expression levels. Finally, multiple antibiotic-type OMPs were found to have higher removal rates in the anaerobic MBR, while associated antibiotic resistance genes were lower. PMID:27441825

  17. Effective control of dental chair unit waterline biofilm and marked reduction of bacterial contamination of output water using two peroxide-based disinfectants.

    PubMed

    Tuttlebee, C M; O'Donnell, M J; Keane, C T; Russell, R J; Sullivan, D J; Falkiner, F; Coleman, D C

    2002-11-01

    Bacterial biofilm in dental unit waterlines (DUWs) is a widespread problem, and poses a potentially significant risk of infection to dental staff and patients, particularly those who are medically compromised or immunocompromised. The purpose of the present study was to investigate the level of bacterial contamination of dental chair unit output water in the Dublin Dental Hospital, and to investigate the efficacy of two hydrogen peroxide-based disinfectants in reducing bacterial loads to < or =200 cfu/mL as recommended by the American Dental Association. The chemical quality of dental chair unit input and output water was well within the limits recommended for potable water. Water supplied to the units yielded an average aerobic heterotrophic bacterial cell density of 184 cfu/mL. However, the corresponding density in output water was considerably higher; the average cell density in water from the three-in-one air/water syringes and cup fillers in 12 chairs was 8200 and 4300 cfu/mL, respectively. Dental unit water obtained from 18 separate reservoir-supplied units in general practices in the Dublin area yielded an average of 66000 cfu/mL. The bacterial species found were predominantly environmental organisms, which were also present at low levels in the input water. Some of the species identified (e.g., Burkholderia cepacia and Pseudomonas fluorescens) are known opportunistic pathogens. The capacity of two disinfectants, Sterilex Ultra and Sanosil, to reduce bacterial contamination to safe levels was compared. In a controlled study, once weekly overnight (15 h) disinfection using either agent reduced the bacterial density to below the American Dental Association recommended level of 200 cfu/mL. However, once disinfection ceased the bacterial loads increased to unacceptably high levels within three weeks. Electron microscopic analysis showed that both disinfectants markedly reduced biofilm in the DUWs, but the biofilm rapidly became extensive again when once weekly

  18. Occurrence of Potential Bacterial Pathogens and Their Antimicrobial Susceptibility Patterns Isolated from Herbal Medicinal Products Sold in Different Markets of Gondar Town, Northwest Ethiopia

    PubMed Central

    Yesuf, Abdela; Wondimeneh, Yitayih; Gebrecherkos, Teklay; Moges, Feleke

    2016-01-01

    Background. The World Health Organization estimates that about 80% of the world's population uses herbal medicine to treat various illnesses as means of primary healthcare. However, during preparation, herbal plants may be exposed to contamination by potential pathogens, and this may lead to infections. The aim of this study was to determine bacterial contamination of herbal medicinal products and to assess the antibiotic susceptibility pattern of the isolated bacteria. Methods. A cross-sectional study was conducted from January 1 to May 25, 2013, at Gondar Town. A total of 55 samples used as oral, local, and intranasal routes of administration were collected from the herbalists. Results. In the present study the total aerobic bacterial count ranges from zero to 2.41 × 109 CFU/g with mean count of 1.99 × 108 CFU/g or mL while the total coliform count showed an average of 1.05 × 108 CFU/g or mL with a range of zero to 2.1 × 109 CFU/g. The most common bacteria isolated were Bacillus spp. followed by Enterobacter spp., Shigella dysenteriae, and Salmonella spp. Multiple drug resistance was not uncommon and it was found that 125 (83.4%) of the isolates were resistant to two or more antibiotics. Conclusion. Herbal medicinal preparations were highly contaminated with pathogenic microorganisms with high microbial load. Most of the isolates have multiple drug resistance. Using those contaminated herbal medicines may lead to infection of other health related risks. Therefore, this warrants urgent training of herbalists and management scale-up for quality and safety of medicinal plants. PMID:27299154

  19. Occurrence of Potential Bacterial Pathogens and Their Antimicrobial Susceptibility Patterns Isolated from Herbal Medicinal Products Sold in Different Markets of Gondar Town, Northwest Ethiopia.

    PubMed

    Yesuf, Abdela; Wondimeneh, Yitayih; Gebrecherkos, Teklay; Moges, Feleke

    2016-01-01

    Background. The World Health Organization estimates that about 80% of the world's population uses herbal medicine to treat various illnesses as means of primary healthcare. However, during preparation, herbal plants may be exposed to contamination by potential pathogens, and this may lead to infections. The aim of this study was to determine bacterial contamination of herbal medicinal products and to assess the antibiotic susceptibility pattern of the isolated bacteria. Methods. A cross-sectional study was conducted from January 1 to May 25, 2013, at Gondar Town. A total of 55 samples used as oral, local, and intranasal routes of administration were collected from the herbalists. Results. In the present study the total aerobic bacterial count ranges from zero to 2.41 × 10(9) CFU/g with mean count of 1.99 × 10(8) CFU/g or mL while the total coliform count showed an average of 1.05 × 10(8) CFU/g or mL with a range of zero to 2.1 × 10(9) CFU/g. The most common bacteria isolated were Bacillus spp. followed by Enterobacter spp., Shigella dysenteriae, and Salmonella spp. Multiple drug resistance was not uncommon and it was found that 125 (83.4%) of the isolates were resistant to two or more antibiotics. Conclusion. Herbal medicinal preparations were highly contaminated with pathogenic microorganisms with high microbial load. Most of the isolates have multiple drug resistance. Using those contaminated herbal medicines may lead to infection of other health related risks. Therefore, this warrants urgent training of herbalists and management scale-up for quality and safety of medicinal plants. PMID:27299154

  20. Experimental Disturbance of Foraminiferal-Bacterial Interactions

    NASA Astrophysics Data System (ADS)

    Langezaal, A. M.; van Bergen, P. F.; van der Zwaan, G. J.

    2003-04-01

    In experiments with living foraminifera, sediment is often sieved prior to incubation in microcosms. This is done to get rid of larger predators, which disturb the sediment and destroy the meiofaunal assemblage. However, the actual sieving results in a sudden disturbance of the obligate anaerobic bacteria. While sieved, they are subjected to aerobe conditions. But also the strictly aerobic bacteria are at a disadvantage when loading the homogenized sediment in microcosms. Normally, their population occurs abundantly in the top oxygenated layer with a thickness of a couple of mm. At the onset of the experiment, however, the aerobe population is mixed through the sediment to become relatively reduced in the top layer. The effects of these disturbances are ill known but might affect the outcome of the experimental foraminiferal and biogeochemical studies substantially. Benthic foraminifera migrate to their natural in-sediment position within three weeks after disturbance. The geochemistry is restored even quicker to the natural situation and it is assumed generally that equilibrium in the sediment has re-established after three weeks (Ernst et al., 2000, Duijnstee et al., 2001). However, some studies suggest that bacterial activity does not recover from the sieving process (Federly et al., 1986; Findley et al., 1990; Gilbert et al., 1995; Schafer et al., 2001) and our data indicate that the bacterial population suffers greatly. We tested an experimental design that has less influence on the bacterial standing stock. The sieving procedure was avoided, intact sediment columns were retrieved from the sea floor and macrofauna was removed by flushing the cores with Argon. In this way the structure of the sediment was kept intact, and no specific groups of bacteria are advantaged at the start of the experiment. The impact of the experimental designs on the outcome of foraminiferal studies is discussed.

  1. Uncertainty in measurements by counting

    NASA Astrophysics Data System (ADS)

    Bich, Walter; Pennecchi, Francesca

    2012-02-01

    Counting is at the base of many high-level measurements, such as, for example, frequency measurements. In some instances the measurand itself is a number of events, such as spontaneous decays in activity measurements, or objects, such as colonies of bacteria in microbiology. Countings also play a fundamental role in everyday life. In any case, a counting is a measurement. A measurement result, according to its present definition, as given in the 'International Vocabulary of Metrology—Basic and general concepts and associated terms (VIM)', must include a specification concerning the estimated uncertainty. As concerns measurements by counting, this specification is not easy to encompass in the well-known framework of the 'Guide to the Expression of Uncertainty in Measurement', known as GUM, in which there is no guidance on the topic. Furthermore, the issue of uncertainty in countings has received little or no attention in the literature, so that it is commonly accepted that this category of measurements constitutes an exception in which the concept of uncertainty is not applicable, or, alternatively, that results of measurements by counting have essentially no uncertainty. In this paper we propose a general model for measurements by counting which allows an uncertainty evaluation compliant with the general framework of the GUM.

  2. A comparison of the distribution of extracellular proteins produced by the protease-secreting organism Aeromonas salmonicida during aerobic and anaerobic growth.

    PubMed

    Fyfe, L; Coleman, G; Munro, A L

    1986-01-01

    Aeromonas salmonicida was grown aerobically and anaerobically in supplemented 3% (w/v) tryptone soya broth medium for 24 h at 25 degrees C. Although the bacterial density achieved was 4.9 times higher in the aerobic culture, the exoprotein produced per unit of bacterial dry weight was only 1.9 times higher than in the anaerobic culture. However, the protease activity of the exoprotein showed a marked reduction anaerobically, being only one-tenth of that of the exoprotein produced aerobically. This finding was consistent with the differing SDS-PAGE patterns of the extracellular proteins from the two cultures, which also showed marked loss and reinforcement of other, as yet unidentified extracellular products. PMID:3322167

  3. Mice can count and optimize count-based decisions.

    PubMed

    Çavdaroğlu, Bilgehan; Balcı, Fuat

    2016-06-01

    Previous studies showed that rats and pigeons can count their responses, and the resultant count-based judgments exhibit the scalar property (also known as Weber's Law), a psychophysical property that also characterizes interval-timing behavior. Animals were found to take a nearly normative account of these well-established endogenous uncertainty characteristics in their time-based decision-making. On the other hand, no study has yet tested the implications of scalar property of numerosity representations for reward-rate maximization in count-based decision-making. The current study tested mice on a task that required them to press one lever for a minimum number of times before pressing the second lever to collect the armed reward (fixed consecutive number schedule, FCN). Fewer than necessary number of responses reset the response count without reinforcement, whereas emitting responses at least for the minimum number of times reset the response counter with reinforcement. Each mouse was tested with three different FCN schedules (FCN10, FCN20, FCN40). The number of responses emitted on the first lever before pressing the second lever constituted the main unit of analysis. Our findings for the first time showed that mice count their responses with scalar property. We then defined the reward-rate maximizing numerical decision strategies in this task based on the subject-based estimates of the endogenous counting uncertainty. Our results showed that mice learn to maximize the reward-rate by incorporating the uncertainty in their numerosity judgments into their count-based decisions. Our findings extend the scope of optimal temporal risk-assessment to the domain of count-based decision-making. PMID:26463617

  4. Bacterial Games

    NASA Astrophysics Data System (ADS)

    Frey, Erwin; Reichenbach, Tobias

    Microbial laboratory communities have become model systems for studying the complex interplay between nonlinear dynamics of evolutionary selection forces, stochastic fluctuations arising from the probabilistic nature of interactions, and spatial organization. Major research goals are to identify and understand mechanisms that ensure viability of microbial colonies by allowing for species diversity, cooperative behavior and other kinds of "social" behavior. A synthesis of evolutionary game theory, nonlinear dynamics, and the theory of stochastic processes provides the mathematical tools and conceptual framework for a deeper understanding of these ecological systems. We give an introduction to the modern formulation of these theories and illustrate their effectiveness, focusing on selected examples of microbial systems. Intrinsic fluctuations, stemming from the discreteness of individuals, are ubiquitous, and can have important impact on the stability of ecosystems. In the absence of speciation, extinction of species is unavoidable, may, however, take very long times. We provide a general concept for defining survival and extinction on ecological time scales. Spatial degrees of freedom come with a certain mobility of individuals. When the latter is sufficiently high, bacterial community structures can be understood through mapping individual-based models, in a continuum approach, onto stochastic partial differential equations. These allow progress using methods of nonlinear dynamics such as bifurcation analysis and invariant manifolds. We conclude with a perspective on the current challenges in quantifying bacterial pattern formation, and how this might have an impact on fundamental research in nonequilibrium physics .

  5. White blood cell counting system

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The design, fabrication, and tests of a prototype white blood cell counting system for use in the Skylab IMSS are presented. The counting system consists of a sample collection subsystem, sample dilution and fluid containment subsystem, and a cell counter. Preliminary test results show the sample collection and the dilution subsystems are functional and fulfill design goals. Results for the fluid containment subsystem show the handling bags cause counting errors due to: (1) adsorption of cells to the walls of the container, and (2) inadequate cleaning of the plastic bag material before fabrication. It was recommended that another bag material be selected.

  6. Big Soda Lake (Nevada). 1. Pelagic bacterial heterotrophy and biomass

    USGS Publications Warehouse

    Zehr, Jon P.; Harvey, Ronald W.; Oremland, Ronald S.; Cloern, James E.; George, Leah H.; Lane, Judith L.

    1987-01-01

    Bacterial activities and abundance were measured seasonally in the water column of meromictic Big Soda Lake which is divided into three chemically distinct zones: aerobic mixolimnion, anaerobic mixolimnion, and anaerobic monimolimnion. Bacterial abundance ranged between 5 and 52 x 106 cells ml−1, with highest biomass at the interfaces between these zones: 2–4 mg C liter−1 in the photosynthetic bacterial layer (oxycline) and 0.8–2.0 mg C liter−1 in the chemocline. Bacterial cell size and morphology also varied with depth: small coccoid cells were dominant in the aerobic mixolimnion, whereas the monimolimnion had a more diverse population that included cocci, rods, and large filaments. Heterotrophic activity was measured by [methyl-3H]thymidine incorporation and [14C]glutamate uptake. Highest uptake rates were at or just below the photosynthetic bacterial layer and were attributable to small (<1 µm) heterotrophs rather than the larger photosynthetic bacteria. These high rates of heterotrophic uptake were apparently linked with fermentation; rates of other mineralization processes (e.g. sulfate reduction, methanogenesis, denitrification) in the anoxic mixolimnion were insignificant. Heterotrophic activity in the highly reduced monimolimnion was generally much lower than elsewhere in the water column. Therefore, although the monimolimnion contained most of the bacterial abundance and biomass (∼60%), most of the cells there were inactive.

  7. Parallel pathways of ethoxylated alcohol biodegradation under aerobic conditions.

    PubMed

    Zembrzuska, Joanna; Budnik, Irena; Lukaszewski, Zenon

    2016-07-01

    Non-ionic surfactants (NS) are a major component of the surfactant flux discharged into surface water, and alcohol ethoxylates (AE) are the major component of this flux. Therefore, biodegradation pathways of AE deserve more thorough investigation. The aim of this work was to investigate the stages of biodegradation of homogeneous oxyethylated dodecanol C12E9 having 9 oxyethylene subunits, under aerobic conditions. Enterobacter strain Z3 bacteria were chosen as biodegrading organisms under conditions with C12E9 as the sole source of organic carbon. Bacterial consortia of river water were used in a parallel test as an inoculum for comparison. The LC-MS technique was used to identify the products of biodegradation. Liquid-liquid extraction with ethyl acetate was selected for the isolation of C12E9 and metabolites from the biodegradation broth. The LC-MS/MS technique operating in the multiple reaction monitoring (MRM) mode was used for quantitative determination of C12E9, C12E8, C12E7 and C12E6. Apart from the substrate, the homologues C12E8, C12E7 and C12E6, being metabolites of C12E9 biodegradation by shortening of the oxyethylene chain, as well as intermediate metabolites having a carboxyl end group in the oxyethylene chain (C12E8COOH, C12E7COOH, C12E6COOH and C12E5COOH), were identified. Poly(ethylene glycols) (E) having 9, 8 and 7 oxyethylene subunits were also identified, indicating parallel central fission of C12E9 and its metabolites. Similar results were obtained with river water as inoculum. It is concluded that AE, under aerobic conditions, are biodegraded via two parallel pathways: by central fission with the formation of PEG, and by Ω-oxidation of the oxyethylene chain with the formation of carboxylated AE and subsequent shortening of the oxyethylene chain by a single unit. PMID:27037882

  8. Microbial degradation of 4-monobrominated diphenyl ether in an aerobic sludge and the DGGE analysis of diversity.

    PubMed

    Chen, Chun-Yao; Wang, Chun-Kang; Shih, Yang-Hsin

    2010-07-01

    Polybrominated diphenyl ethers (PBDEs) were applied as flame retardant additives in polymers for many plastic and electronic products. Due to their ubiquitous distribution in the environment, potential toxicity to human and tendency for bioaccumulation, PBDEs have raised public safety concern. In this study we examined the degradation of 4-monobrominated diphenyl ether (4-BDE) in aerobic sludge, as a model for PBDE biodegradation. Degradation of 4-BDE was observed in aerobic sludge. Co-metabolism with toluene or diphenyl ether facilitated 4-BDE biodegradation in terms of kinetics and efficiency. Diphenyl ether seems to perform slightly better as an auxiliary carbon source than toluene in facilitating 4-BDE degradation. During the experiment we identified diphenyl ether by gas chromatography/mass spectrometry(GC/MS), which indicates that an anaerobic debromination has occurred. Bacterial community composition was monitored with denaturing gradient gel electrophoresis. The fragments enriched in 4-BDE-degrading aerobic sludge samples belong to presumably a novel anaerobic Clostridiales species distantly related to all known debrominating microbes. This suggests that 4-BDE biodegradation can occur in anaerobic micro-niche in an apparently aerobic environment, by a previously unknown bacterial species. These findings can provide better understandings of biodegradation of brominated diphenyl ethers and can facilitate the prediction of the fate of PBDEs in the environment. PMID:20512728

  9. Bacterial enteropathogens in Malaysian shellfish.

    PubMed

    Jegathesan, M; Wah, L T; Soon, L E; Su Har, D; Boo Liat, L

    1976-06-01

    Three species of commonly eaten shellfish found in Malaysian coastal waters were examined for the presence of common bacterial enteropathogens. Vibrio parahaemolyticus, non-agglutinating vibrios, and various serotypes of enteropathogenic E. coli were isolated from a large proportion of them. Salmonella were isolated in two instances. High colony counts with evidence of faecal contamination indicated the strong possibility of pulltion being the cause for the presence of these enteropathogens. Methods of cooking and eating these shellfish enhance their likelihood of acting as vehicles of diarrhoeal disease. PMID:788266

  10. Tracing organic compounds in aerobically altered methane-derived carbonate pipes (Gulf of Cadiz, SW Iberia)

    NASA Astrophysics Data System (ADS)

    Merinero, Raúl; Ruiz-Bermejo, Marta; Menor-Salván, César; Lunar, Rosario; Martínez-Frías, Jesús

    2012-07-01

    The primary geochemical process at methane seeps is anaerobic oxidation of methane (AOM), performed by methanotrophic archaea and sulfate-reducing bacteria (SRB). The molecular fingerprints (biomarkers) of these chemosynthetic microorganisms can be preserved in carbonates formed through AOM. However, thermal maturity and aerobic degradation can change the original preserved compounds, making it difficult to establish the relation between AOM and carbonate precipitation. Here we report a study of amino acid and lipid abundances in carbonate matrices of aerobically altered pipes recovered from the seafloor of the Gulf of Cadiz (SW Iberian Peninsula). This area is characterized by a complex tectonic regime that supports numerous cold seeps. Studies so far have not determined whether the precipitation of carbonate pipes in the Gulf of Cadiz is a purely chemical process or whether microbial communities are involved. Samples from this site show signs of exposure to oxygenated waters and of aerobic alteration, such as oxidation of authigenic iron sulfides. In addition, the degradation index, calculated from the relative abundance of preserved amino acids, indicates aerobic degradation of organic matter. Although crocetane was the only lipid identified from methanotrophic archaea, the organic compounds detected (n-alkanes, regular isoprenoids and alcohols) are compatible with an origin from AOM coupled with bacterial sulfate reduction (BSR) and subsequent aerobic degradation. We establish a relation among AOM, BSR and pipe formation in the Gulf of Cadiz through three types of analysis: (1) stable carbon and oxygen isotopic composition of carbonate minerals; (2) carbonate microfabrics; and (3) mineralogical composition. Our results suggest that carbonate pipes may form through a process similar to the precipitation of vast amounts of carbonate pavements often found at cold seeps. Our approach suggests that some organic compound patterns, in combination with additional

  11. Aerobic and anaerobic microbial degradation of crude (4-methylcyclohexyl)methanol in river sediments.

    PubMed

    Yuan, Li; Zhi, Wei; Liu, Yangsheng; Smiley, Elizabeth; Gallagher, Daniel; Chen, Xi; Dietrich, Andrea; Zhang, Husen

    2016-03-15

    Cyclohexane and some of its derivatives have been a major concern because of their significant adverse human health effects and widespread occurrence in the environment. The 2014 West Virginia chemical spill has raised public attention to (4-methylcyclohexyl)methanol (4-MCHM), one cyclohexane derivative, which is widely used in coal processing but largely ignored. In particular, the environmental fate of its primary components, cis- and trans-4-MCHM, remains largely unexplored. This study aimed to investigate the degradation kinetics and mineralization of cis- and trans-4-MCHM by sediment microorganisms under aerobic and anaerobic conditions. We found the removal of cis- and trans-4-MCHM was mainly attributed to biodegradation with little contribution from sorption. A nearly complete aerobic degradation of 4-MCHM occurred within 14 days, whereas the anaerobic degradation was reluctant with residual percentages of 62.6% of cis-4-MCHM and 85.0% of trans-4-MCHM after 16-day incubation. The cis-4-MCHM was degraded faster than the trans under both aerobic and anaerobic conditions, indicating an isomer-specific degradation could occur during the 4-MCHM degradation. Nitrate addition enhanced 4-MCHM mineralization by about 50% under both aerobic and anaerobic conditions. Both cis- and trans-4-MCHM fit well with the first-order kinetic model with respective degradation rates of 0.46-0.52 and 0.19-0.31 day(-)(1) under aerobic condition. Respective degradation rates of 0.041-0.095 and 0.013-0.052 day(-)(1) occurred under anaerobic condition. One bacterial strain capable of effectively degrading 4-MCHM isomers was isolated from river sediments and identified as Bacillus pumilus at the species level based on 16S rRNA gene sequence and 97% identity. Our findings will provide critical information for improving the prediction of the environmental fate of 4-MCHM and other cyclohexane derivatives with similar structure as well as enhancing the development of feasible treatment

  12. INACTIVATION OF ENTERIC PATHOGENS DURING AEROBIC DIGESTION OF WASTEWATER SLUDGE

    EPA Science Inventory

    The effects of aerobic and anaerobic digestion on enteric viruses, enteric bacteria, total aerobic bacteria, and intestinal parasites were studied under laboratory and field conditions. Under laboratory conditions, the temperature of the sludge digestion was the major factor infl...

  13. ANAEROBIC AND AEROBIC TREATMENT OF CHLORINATED ALIPHATIC COMPOUNDS

    EPA Science Inventory

    Biological degradation of 12 chlorinated aliphatic compounds (CACs) was assessed in bench-top reactors and in serum bottle tests. Three continuously mixed daily batch-fed reactor systems were evaluated: anaerobic, aerobic, and sequential-anaerobic-aerobic (sequential). Glucose,...

  14. Space agriculture for habitation on Mars with hyper-thermophilic aerobic composting bacteria

    NASA Astrophysics Data System (ADS)

    Kanazawa, S.; Ishikawa, Y.; Tomita-Yokotani, K.; Hashimoto, H.; Kitaya, Y.; Yamashita, M.; Nagatomo, M.; Oshima, T.; Wada, H.; Space Agriculture Task Force, J.

    Manned Mars exploration requires recycle of materials to support human life A conceptual design is developed for space agriculture which is driven by the biologically regenerative function Hyper-thermophilic aerobic composting bacterial ecology is the core of materials recycling system to process human metabolic waste and inedible biomass and convert them to fertilizer for plants cultivation A photosynthetic reaction of plants will be driven by solar energy Water will be recycled by cultivation of plants and passing it through plant bodies Sub-surface water and atmospheric carbon dioxide are the natural resource available on Mars and these resources will be converted to oxygen and foods We envision that the agricultural system will be scaled up by importing materials from Martian environment Excess oxygen will be obtained from growing trees for structural and other components Minor elements including N P K and other traces will be introduced as fertilizers or nutrients into the agricultural materials circulation Nitrogen will be collected from Martian atmosphere We will assess biological fixation of nitrogen using micro-organisms responsible in Earth biosphere Hyper-thermophilic aerobic bacterial ecology is effective to convert waste materials into useful forms to plants This microbial technology has been well established on ground for processing sewage and waste materials For instance the hyper-thermophilic bacterial system is applied to a composting machine in a size of a trash box in home kitchen Since such a home electronics

  15. Aerobic Mercury-resistant bacteria alter Mercury speciation and retention in the Tagus Estuary (Portugal).

    PubMed

    Figueiredo, Neusa L; Canário, João; O'Driscoll, Nelson J; Duarte, Aida; Carvalho, Cristina

    2016-02-01

    Aerobic mercury-resistant bacteria were isolated from the sediments of two highly mercury-polluted areas of the Tagus Estuary (Barreiro and Cala do Norte) and one natural reserve area (Alcochete) in order to test their capacity to transform mercury. Bacterial species were identified using 16S rRNA amplification and sequencing techniques and the results indicate the prevalence of Bacillus sp. Resistance patterns to mercurial compounds were established by the determination of minimal inhibitory concentrations. Representative Hg-resistant bacteria were further tested for transformation pathways (reduction, volatilization and methylation) in cultures containing mercury chloride. Bacterial Hg-methylation was carried out by Vibrio fluvialis, Bacillus megaterium and Serratia marcescens that transformed 2-8% of total mercury into methylmercury in 48h. In addition, most of the HgR bacterial isolates showed Hg(2+)-reduction andHg(0)-volatilization resulting 6-50% mercury loss from the culture media. In summary, the results obtained under controlled laboratory conditions indicate that aerobic Hg-resistant bacteria from the Tagus Estuary significantly affect both the methylation and reduction of mercury and may have a dual face by providing a pathway for pollution dispersion while forming methylmercury, which is highly toxic for living organisms. PMID:26461264

  16. Evaluation of nitrate removal by continuous culturing of an aerobic denitrifying bacterium, Paracoccus pantotrophus.

    PubMed

    Hasegawa-Kurisu, K; Otani, Y; Hanaki, K

    2006-01-01

    Nitrate removal under aerobic conditions was investigated using pure cultures of Paracoccus pantotrophus, which is a well-known aerobic-denitrifying (AD) bacterium. When a high concentration of cultures with a high carbon/nitrogen (C/N) ratio was preserved at the beginning of batch experiments, subsequently added nitrate was completely removed. When continuous culturing was perpetuated, a high nitrate removal rate (66.5%) was observed on day 4 post-culture, although gradual decreases in AD ability with time were observed. The attenuation in AD ability was probably caused by carbon limitation, because when carbon concentration of inflow water was doubled, nitrate removal efficiency improved from 18.1% to 59.6%. Bacterial community analysis using the polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method showed that P. pantotrophus disappeared in the suspended medium on day 8 post-culture, whereas other bacterial communities dominated by Acidovorax sp. appeared. Interestingly, this replaced bacterial community also showed AD ability. As P. pantotrophus was detected as attached colonies around the membrane and bottom of the reactor, this bacterium can therefore be introduced in a fixed form for treatment of wastewater containing nitrate with a high C/N ratio. PMID:17163031

  17. Treatment of phenolics, aromatic hydrocarbons, and cyanide-bearing wastewater in individual and combined anaerobic, aerobic, and anoxic bioreactors.

    PubMed

    Sharma, Naresh K; Philip, Ligy

    2015-01-01

    Studies were conducted on a mixture of pollutants commonly found in coke oven wastewater (CWW) to evaluate the biodegradation of various pollutants under anaerobic, aerobic, and anoxic conditions. The removal of the pollutants was monitored during individual bioreactor operation and using a combination of bioreactors operating in anaerobic-aerobic-anoxic sequence. While studying the performance of individual reactors, it was observed that cyanide removal (83.3 %) was predominant in the aerobic bioreactor, while much of the chemical oxygen demand (COD) (69 %) was consumed in the anoxic bioreactor. With the addition of cyanide, the COD removal efficiency was affected in all the bioreactors, and several intermediates were detected. While treating synthetic CWW using the combined bioreactor system, the overall COD removal efficiency was 86.79 % at an OLR of 2.4 g COD/L/day and an HRT of 96 h. The removal efficiency of 3,5-xylenol and cyanide, with inlet concentration of 150 and 10 mg/L, was found to be 91.8 and 93.6 % respectively. It was found that the impact of xylenol on the performance of the bioreactors was less than cyanide toxicity. Molecular analysis using T-RFLP revealed the dominance of strictly aerobic, mesophilic proteobacterium, Bosea minatitlanensis, in the aerobic bioreactor. The anoxic bioreactor was dominant with Rhodococcus pyridinivorans, known for its remarkable aromatic decomposing activity, while an unclassified Myxococcales bacterium was identified as the predominant bacterial species in the anaerobic bioreactor. PMID:25267355

  18. Complete Blood Count (For Parents)

    MedlinePlus

    ... KidsHealth in the Classroom What Other Parents Are Reading Upsetting News Reports? What to Say Vaccines: Which ... Metabolic Panel (BMP) Blood Test: Hemoglobin Basic Blood Chemistry Tests Word! Complete Blood Count (CBC) Medical Tests ...

  19. Counting Triangles to Sum Squares

    ERIC Educational Resources Information Center

    DeMaio, Joe

    2012-01-01

    Counting complete subgraphs of three vertices in complete graphs, yields combinatorial arguments for identities for sums of squares of integers, odd integers, even integers and sums of the triangular numbers.

  20. Counting on Using a Number Game

    ERIC Educational Resources Information Center

    Betts, Paul

    2015-01-01

    Counting all and counting on are distinct counting strategies that can be used to compute such quantities as the total number of objects in two sets (Wright, Martland, and Stafford 2010). Given five objects and three more objects, for example, children who use counting all to determine quantity will count both collections; that is, they count…

  1. Bacterial contamination of automotive fuels in a tropical region: the case of Costa Rica.

    PubMed

    Rodríguez-Rodríguez, Carlos E; Rodríguez-Cavallini, Evelyn; Blanco, Rigoberto

    2009-09-01

    Microbial contamination of fuel has been the cause of several problems in transportation and storage of these products. Due to the lack of previous studies related to these problems in Costa Rica, bacterial quality was evaluated biannually in automotive fuels stored in the four oil distribution facilities of the Costa Rican Petroleum Refinery (RECOPE). In 12 oil storage tanks, for a total of 96 samples, mesophilic, heterotrophic aerobic/facultative counts (ASTM D6974-04) and identification of bacteria presented in regular gas, premium gas and diesel from the bottom and superior part of the tanks were done; in the samples containing an aqueous phase, sulfate reducing bacteria (SRB) were also quantified by the most probable number technique (MPN), according to the ASTM D4412-84 standard. The higher contamination was shown at the bottom of the tanks (populations up to 10(4) UFC/l), especially if there was accumulated water, in which case populations reached 10(8) UFC/l. The most contaminated fuel was diesel (counts up to 10(4) UFC/l), whereas the less contaminated was premium gas. The less contaminated fuels were from the facilities of La Garita and Barranca, whereas the most contaminated were from Ochomogo. Nevertheless, the quantified populations did not cause significant alteration in quality physicochemical parameters in the samples analyzed. A total of 149 bacterial strains were isolated, 136 (91.3%) Gram positive and 13 (8.7%) Gram negative. The most frequent genera were Staphylococcus (24.0%), Micrococcus (21.9%), Bacillus (18.8%) and Kocuria (11.5%) among Gram positive bacteria and Pseudomonas (7.3%) among Gram negative bacteria. The majority of these genera have been found as fuel contaminants or even as degraders of this kind of products; nevertheless, some species for which their appearance or growth in hydrocarbons have not been described were found with low frequencies. SRB were present in counts up to 10(5) MPN/l in 42.9% of water containing samples

  2. Bacterial Hydrodynamics

    NASA Astrophysics Data System (ADS)

    Lauga, Eric

    2016-01-01

    Bacteria predate plants and animals by billions of years. Today, they are the world's smallest cells, yet they represent the bulk of the world's biomass and the main reservoir of nutrients for higher organisms. Most bacteria can move on their own, and the majority of motile bacteria are able to swim in viscous fluids using slender helical appendages called flagella. Low-Reynolds number hydrodynamics is at the heart of the ability of flagella to generate propulsion at the micrometer scale. In fact, fluid dynamic forces impact many aspects of bacteriology, ranging from the ability of cells to reorient and search their surroundings to their interactions within mechanically and chemically complex environments. Using hydrodynamics as an organizing framework, I review the biomechanics of bacterial motility and look ahead to future challenges.

  3. Reflections on Psychotherapy and Aerobic Exercise.

    ERIC Educational Resources Information Center

    Silverman, Wade

    This document provides a series of reflections by a practicing psychologist on the uses of aerobic workouts in psychotherapy. Two case histories are cited to illustrate the contention that the mode of exercise, rather than simply its presence or absence, is the significant indicator of a patient's emotional well-being or psychopathology. The first…

  4. Aerobic Exercise Prescription for Rheumatoid Arthritics.

    ERIC Educational Resources Information Center

    Evans, Blanche W.; Williams, Hilda L.

    The use of exercise as a general treatment for rheumatoid arthritics (RA) has included range of motion, muscular strength, water exercise and rest therapy while virtually ignoring possible benefits of aerobic exercise. The purposes of this project were to examine the guidelines for exercise prescription in relation to this special population and…

  5. Response of aerobic rice to Piriformospora indica.

    PubMed

    Das, Joy; Ramesh, K V; Maithri, U; Mutangana, D; Suresh, C K

    2014-03-01

    Rice cultivation under aerobic condition not only saves water but also opens up a splendid scope for effective application of beneficial root symbionts in rice crop unlike conventional puddled rice cultivation where water logged condition acts as constraint for easy proliferation of various beneficial soil microorganisms like arbuscular mycorrhizal (AM) fungi. Keeping these in view, an in silico investigation were carried out to explore the interaction of hydrogen phosphate with phosphate transporter protein (PTP) from P. indica. This was followed by greenhouse investigation to study the response of aerobic rice to Glomusfasciculatum, a conventional P biofertilizer and P. indica, an alternative to AM fungi. Computational studies using ClustalW tool revealed several conserved motifs between the phosphate transporters from Piriformospora indica and 8 other Glomus species. The 3D model of PTP from P. indica resembling "Mayan temple" was successfully docked onto hydrogen phosphate, indicating the affinity of this protein for inorganic phosphorus. Greenhouse studies revealed inoculation of aerobic rice either with P. indica, G. fasciculatum or both significantly enhanced the plant growth, biomass and yield with higher NPK, chlorophyll and sugar compared to uninoculated ones, P. indica inoculated plants being superior. A significantly enhanced activity of acid phosphatase and alkaline phosphatase were noticed in the rhizosphere soil of rice plants inoculated either with P. indica, G. fasciculatum or both, contributing to higher P uptake. Further, inoculation of aerobic rice plants with P. indica proved to be a better choice as a potential biofertilizer over mycorrhiza. PMID:24669667

  6. Media for the aerobic growth of campylobacter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of agar and sodium bicarbonate (NaHCO3) concentration on aerobic growth of Campylobacter in a fumarate-pyruvate medium was examined. The broth medium was supplemented with 0.0 to 0.2% agar and inoculated with 106 CFU/ml of Campylobacter coli 33559, Campylobacter fetus 27349, Campylobacter...

  7. Strengthening aerobic granule by salt precipitation.

    PubMed

    Chen, Yu-You; Pan, Xiangliang; Li, Jun; Lee, Duu-Jong

    2016-10-01

    Structural stability of aerobic granules is generally poor during long-term operation. This study precipitated seven salts inside aerobic granules using supersaturated solutions of (NH4)3PO4, CaCO3, CaSO4, MgCO3, Mg3(PO4)2, Ca3(PO4)2 or SiO2 to enhance their structural stability. All precipitated granules have higher interior strength at ultrasonic field and reveal minimal loss in organic matter degradation capability at 160-d sequential batch reactor tests. The strength enhancement followed: Mg3(PO4)2=CaSO4>SiO2>(NH4)3PO4>MgCO3>CaCO3=Ca3(PO4)2>original. Also, the intra-granular solution environment can be buffered by the precipitate MgCO3 to make the aerobic granules capable of degradation of organic matters at pH 3. Salt precipitation is confirmed a simple and cost-effective modification method to extend the applicability of aerobic granules for wastewater treatments. PMID:27377228

  8. AEROBIC DENITRIFICATION: IMPLICATIONS FOR NITROGEN FATE MODELING

    EPA Science Inventory

    In the Mississippi, as well as most nitrogen-degraded rivers and streams, NO3- is the dominant N species and therefore understanding its biogeochemical behavior is critical for accurate nitrogen fate modeling. To our knowledge this is the first work to report aerobic denitrificat...

  9. Anaerobic and aerobic transformation of TNT

    SciTech Connect

    Kulpa, C.F.; Boopathy, R.; Manning, J.

    1996-12-31

    Most studies on the microbial metabolism of nitroaromatic compounds have used pure cultures of aerobic microorganisms. In many cases, attempts to degrade nitroaromatics under aerobic conditions by pure cultures result in no mineralization and only superficial modifications of the structure. However, mixed culture systems properly operated result in the transformation of 2,4,6-trinitrotoluene (TNT) and in some cases mineralization of TNT occurs. In this paper, the mixed culture system is described with emphasis on intermediates and the characteristics of the aerobic microbial process including the necessity for a co-substrate. The possibility of removing TNT under aerobic/anoxic conditions is described in detail. Another option for the biodegradation of TNT and nitroaromatics is under anaerobic, sulfate reducing conditions. In this instance, the nitroaromatic compounds undergo a series of reductions with the formation of amino compounds. TNT under sulfate reducing conditions is reduced to triaminotoluene presumably by the enzyme nitrite reductase, which is commonly found in many Desulfovibrio spp. The removal of nitro groups from TNT is achieved by a series of reductive reactions with the formation of ammonia and toluene by Desulfovibrio sp. (B strain). These metabolic processes could be applied to other nitroaromatic compounds like nitrobenzene, nitrobenzoic acids, nitrophenols, and aniline. The data supporting the anaerobic transformation of TNT under different growth condition are reviewed in this report.

  10. Ventilation and Speech Characteristics during Submaximal Aerobic Exercise

    ERIC Educational Resources Information Center

    Baker, Susan E.; Hipp, Jenny; Alessio, Helaine

    2008-01-01

    Purpose: This study examined alterations in ventilation and speech characteristics as well as perceived dyspnea during submaximal aerobic exercise tasks. Method: Twelve healthy participants completed aerobic exercise-only and simultaneous speaking and aerobic exercise tasks at 50% and 75% of their maximum oxygen consumption (VO[subscript 2] max).…

  11. Adolescents' Interest and Performances in Aerobic Fitness Testing

    ERIC Educational Resources Information Center

    Zhu, Xihe; Chen, Senlin; Parrott, James

    2014-01-01

    This study examined adolescents' interest in aerobic fitness testing and its relation to the test performances. Adolescents (N = 356) from three middle schools participated in the study. The participants took two aerobic fitness tests: the Progressive Aerobic Cardiovascular Endurance Run (PACER) and One-Mile Run (1MR) with a two-day interval,…

  12. A proposed aerobic granules size development scheme for aerobic granulation process.

    PubMed

    Dahalan, Farrah Aini; Abdullah, Norhayati; Yuzir, Ali; Olsson, Gustaf; Salmiati; Hamdzah, Myzairah; Din, Mohd Fadhil Mohd; Ahmad, Siti Aqlima; Khalil, Khalilah Abdul; Anuar, Aznah Nor; Noor, Zainura Zainon; Ujang, Zaini

    2015-04-01

    Aerobic granulation is increasingly used in wastewater treatment due to its unique physical properties and microbial functionalities. Granule size defines the physical properties of granules based on biomass accumulation. This study aims to determine the profile of size development under two physicochemical conditions. Two identical bioreactors namely Rnp and Rp were operated under non-phototrophic and phototrophic conditions, respectively. An illustrative scheme was developed to comprehend the mechanism of size development that delineates the granular size throughout the granulation. Observations on granules' size variation have shown that activated sludge revolutionised into the form of aerobic granules through the increase of biomass concentration in bioreactors which also determined the changes of granule size. Both reactors demonstrated that size transformed in a similar trend when tested with and without illumination. Thus, different types of aerobic granules may increase in size in the same way as recommended in the aerobic granule size development scheme. PMID:25661308

  13. Antimicrobial Susceptibility of Enteric Gram Negative Facultative Anaerobe Bacilli in Aerobic versus Anaerobic Conditions

    PubMed Central

    Amachawadi, Raghavendra G.; Renter, David G.; Volkova, Victoriya V.

    2016-01-01

    Antimicrobial treatments result in the host’s enteric bacteria being exposed to the antimicrobials. Pharmacodynamic models can describe how this exposure affects the enteric bacteria and their antimicrobial resistance. The models utilize measurements of bacterial antimicrobial susceptibility traditionally obtained in vitro in aerobic conditions. However, in vivo enteric bacteria are exposed to antimicrobials in anaerobic conditions of the lower intestine. Some of enteric bacteria of food animals are potential foodborne pathogens, e.g., Gram-negative bacilli Escherichia coli and Salmonella enterica. These are facultative anaerobes; their physiology and growth rates change in anaerobic conditions. We hypothesized that their antimicrobial susceptibility also changes, and evaluated differences in the susceptibility in aerobic vs. anaerobic conditions of generic E. coli and Salmonella enterica of diverse serovars isolated from cattle feces. Susceptibility of an isolate was evaluated as its minimum inhibitory concentration (MIC) measured by E-Test® following 24 hours of adaptation to the conditions on Mueller-Hinton agar, and on a more complex tryptic soy agar with 5% sheep blood (BAP) media. We considered all major antimicrobial drug classes used in the U.S. to treat cattle: β-lactams (specifically, ampicillin and ceftriaxone E-Test®), aminoglycosides (gentamicin and kanamycin), fluoroquinolones (enrofloxacin), classical macrolides (erythromycin), azalides (azithromycin), sulfanomides (sulfamethoxazole/trimethoprim), and tetracyclines (tetracycline). Statistical analyses were conducted for the isolates (n≥30) interpreted as susceptible to the antimicrobials based on the clinical breakpoint interpretation for human infection. Bacterial susceptibility to every antimicrobial tested was statistically significantly different in anaerobic vs. aerobic conditions on both media, except for no difference in susceptibility to ceftriaxone on BAP agar. A satellite experiment

  14. Selecting anti-microbial treatment of aerobic vaginitis.

    PubMed

    Donders, Gilbert G G; Ruban, Katerina; Bellen, Gert

    2015-05-01

    Aerobic vaginitis (AV) is a vaginal infectious condition which is often confused with bacterial vaginosis (BV) or with the intermediate microflora as diagnosed by Nugent's method to detect BV on Gram-stained specimens. However, although both conditions reflect a state of lactobacillary disruption in the vagina, leading to an increase in pH, BV and AV differ profoundly. While BV is a noninflammatory condition composed of a multiplex array of different anaerobic bacteria in high quantities, AV is rather sparely populated by one or two enteric commensal flora bacteria, like Streptococcus agalactiae, Staphylocuccus aureus, or Escherichia coli. AV is typically marked by either an increased inflammatory response or by prominent signs of epithelial atrophy or both. The latter condition, if severe, is also called desquamative inflammatory vaginitis. As AV is per exclusionem diagnosed by wet mount microscopy, it is a mistake to treat just vaginal culture results. Vaginal cultures only serve as follow-up data in clinical research projects and are at most used in clinical practice to confirm the diagnosis or exclude Candida infection. AV requires treatment based on microscopy findings and a combined local treatment with any of the following which may yield the best results: antibiotic (infectious component), steroids (inflammatory component), and/or estrogen (atrophy component). In cases with Candida present on microscopy or culture, antifungals must be tried first in order to see if other treatment is still needed. Vaginal rinsing with povidone iodine can provide rapid relief of symptoms but does not provide long-term reduction of bacterial loads. Local antibiotics most suitable are preferably non-absorbed and broad spectrum, especially those covering enteric gram-positive and gram-negative aerobes, like kanamycin. To achieve rapid and short-term improvement of severe symptoms, oral therapy with amoxyclav or moxifloxacin can be used, especially in deep dermal vulvitis and

  15. Distribution and Physiology of Aerobic Bacteria Containing Bacteriochlorophyll a on the East and West Coasts of Australia †

    PubMed Central

    Shiba, Tsuneo; Shioi, Yuzo; Takamiya, Ken-Ichiro; Sutton, David C.; Wilkinson, Clive R.

    1991-01-01

    Aerobic heterotrophic bacteria containing bacteriochlorophyll were isolated from specimens from a wide variety of marine environments on the west (Shark Bay, Lake Clifton, Lake Heyward, and Perth) and east (near Townsville and Brisbane) coasts of Australia. The bacteria were found in a high proportion (10 to 30%) of the total heterotrophic bacterial strains isolated from marine algae, seagrasses, stromatolites, the epiphytes on stromatolites, seawater, and sands; in some cases they constituted up to 49% of the total. This is much higher than the previous report of 6% from Japan. A high percentage, 13%, was also found in the seawater of Hamelin Pool, at Shark Bay, where the salinity was 66%. The number of these bacteria was generally low in seawater and sands, with a few exceptions. There were no aerobic bacteriochlorophyll-containing bacteria on sponges or corals. The isolated strains were orange or pink, and most had absorption maxima around 800 and 850 to 870 nm, the latter range being the absorption of bacteriochlorophyll a in vivo. The maximum bacteriochlorophyll content was 1 nmol/mg (dry weight) of bacterial cells. Most of the bacteria did not grow phototrophically under anaerobic conditions in a broth medium containing succinate. Cells and cell extracts grown under aerobic conditions had photochemical activities such as reversible photooxidations of the reaction center and cytochrome(s). Some strains showed denitrifying activity. The optimal salinity for bacterial growth varied between strains. PMID:16348398

  16. Detection of bacterial concentration variations based on dielectric magnetic flux.

    PubMed

    Chen, Jingyao; Cai, Jie; Huang, Xingjian; Yi, Tian; Wang, Kexing; Pan, Siyi

    2016-02-01

    This study is based on the development of bacterial count quantification generated by medium dielectric variations and consequent polarization material release. The proposed approach is an action method for the fast detection of bacterial concentration in orange juice. The sensing method relies on bacterial attachment up to biofilm formation. Furthermore, different media provide more oxygen group content to enhance capacitance and self-discharge. The test took only 30 min and it provided the means for rapid bacterial detection in the juice industry. PMID:26304394

  17. Batch culture enrichment of ANAMMOX populations from anaerobic and aerobic seed cultures.

    PubMed

    Suneethi, S; Joseph, Kurian

    2011-01-01

    Discharge of nitrate and ammonia rich wastewaters into the natural waters encourage eutrophication, and contribute to aquatic toxicity. Anaerobic ammonium oxidation process (ANAMMOX) is a novel biological nitrogen removal alternative to nitrification-denitrification, that removes ammonia using nitrite as the electron acceptor. The feasibility of enriching the ANAMMOX bacteria from the anaerobic digester sludge of a biomethanation plant treating vegetable waste and aerobic sludge from an activated sludge process treating domestic sewage is reported in this paper. ANAMMOX bacterial activity was monitored and established in terms of nitrogen transformations to ammonia, nitrite and nitrate along with formation of hydrazine and hydroxylamine. PMID:20729077

  18. The bacterial proteogenomic pipeline

    PubMed Central

    2014-01-01

    Background Proteogenomics combines the cutting-edge methods from genomics and proteomics. While it has become cheap to sequence whole genomes, the correct annotation of protein coding regions in the genome is still tedious and error prone. Mass spectrometry on the other hand relies on good characterizations of proteins derived from the genome, but can also be used to help improving the annotation of genomes or find species specific peptides. Additionally, proteomics is widely used to find evidence for differential expression of proteins under different conditions, e.g. growth conditions for bacteria. The concept of proteogenomics is not altogether new, in-house scripts are used by different labs and some special tools for eukaryotic and human analyses are available. Results The Bacterial Proteogenomic Pipeline, which is completely written in Java, alleviates the conducting of proteogenomic analyses of bacteria. From a given genome sequence, a naïve six frame translation is performed and, if desired, a decoy database generated. This database is used to identify MS/MS spectra by common peptide identification algorithms. After combination of the search results and optional flagging for different experimental conditions, the results can be browsed and further inspected. In particular, for each peptide the number of identifications for each condition and the positions in the corresponding protein sequences are shown. Intermediate and final results can be exported into GFF3 format for visualization in common genome browsers. Conclusions To facilitate proteogenomics analyses the Bacterial Proteogenomic Pipeline is a set of comprehensive tools running on common desktop computers, written in Java and thus platform independent. The pipeline allows integrating peptide identifications from various algorithms and emphasizes the visualization of spectral counts from different experimental conditions. PMID:25521444

  19. Bacterial diversity in faeces from polar bear (Ursus maritimus) in Arctic Svalbard

    PubMed Central

    2010-01-01

    Background Polar bears (Ursus maritimus) are major predators in the Arctic marine ecosystem, feeding mainly on seals, and living closely associated with sea ice. Little is known of their gut microbial ecology and the main purpose of this study was to investigate the microbial diversity in faeces of polar bears in Svalbard, Norway (74-81°N, 10-33°E). In addition the level of blaTEM alleles, encoding ampicillin resistance (ampr) were determined. In total, ten samples were collected from ten individual bears, rectum swabs from five individuals in 2004 and faeces samples from five individuals in 2006. Results A 16S rRNA gene clone library was constructed, and all sequences obtained from 161 clones showed affiliation with the phylum Firmicutes, with 160 sequences identified as Clostridiales and one sequence identified as unclassified Firmicutes. The majority of the sequences (70%) were affiliated with the genus Clostridium. Aerobic heterotrophic cell counts on chocolate agar ranged between 5.0 × 104 to 1.6 × 106 colony forming units (cfu)/ml for the rectum swabs and 4.0 × 103 to 1.0 × 105 cfu/g for the faeces samples. The proportion of ampr bacteria ranged from 0% to 44%. All of 144 randomly selected ampr isolates tested positive for enzymatic β-lactamase activity. Three % of the ampr isolates from the rectal samples yielded positive results when screened for the presence of blaTEM genes by PCR. BlaTEM alleles were also detected by PCR in two out of three total faecal DNA samples from polar bears. Conclusion The bacterial diversity in faeces from polar bears in their natural environment in Svalbard is low compared to other animal species, with all obtained clones affiliating to Firmicutes. Furthermore, only low levels of blaTEM alleles were detected in contrast to their increasing prevalence in some clinical and commensal bacterial populations. PMID:20074323

  20. Effects of Aerobic Exercise Training on Fitness and Walking Related Outcomes in Ambulatory Individuals with Chronic Incomplete Spinal Cord Injury

    PubMed Central

    DiPiro, Nicole D.; Embry, Aaron E.; Fritz, Stacy L.; Middleton, Addie; Krause, James S.; Gregory, Chris M.

    2015-01-01

    Study Design Single group, pretest-posttest study. Objectives To determine the effects of a non-task-specific, voluntary, progressive aerobic exercise training (AET) intervention on fitness and walking-related outcomes in ambulatory adults with chronic motor-incomplete SCI. Setting Rehabilitation research center. Methods Ten ambulatory individuals (50% female; 57.94 ± 9.33 years old; 11.11 ± 9.66 years post injury) completed voluntary, progressive moderate-to-vigorous intensity AET on a recumbent stepper three days per week for six weeks. The primary outcome measures were aerobic capacity (VO2peak) and self-selected overground walking speed (OGWS). Secondary outcome measures included: walking economy, six-minute walk test (6MWT), daily step counts, Walking Index for Spinal Cord Injury (WISCI-II), Dynamic Gait Index (DGI), and Berg Balance Scale (BBS). Results Nine participants completed all testing and training. Significant improvements in aerobic capacity (P=0.011), OGWS (P=0.023), the percentage of VO2peak utilized while walking at self-selected speed (P=0.03), and daily step counts (P=0.025) resulted following training. Conclusions The results indicate that total-body, voluntary, progressive AET is safe, feasible, and effective for improving aerobic capacity, walking speed, and select walking-related outcomes in an exclusively ambulatory SCI sample. This study suggests the potential for non-task-specific aerobic exercise to improve walking following incomplete SCI and builds a foundation for further investigation aimed at the development of exercise based rehabilitation strategies to target functionally limiting impairments in ambulatory individuals with chronic SCI. PMID:26666508

  1. Hanford whole body counting manual

    SciTech Connect

    Palmer, H.E.; Rieksts, G.A.; Lynch, T.P.

    1990-06-01

    This document describes the Hanford Whole Body Counting Program as it is administered by Pacific Northwest Laboratory (PNL) in support of the US Department of Energy--Richland Operations Office (DOE-RL) and its Hanford contractors. Program services include providing in vivo measurements of internally deposited radioactivity in Hanford employees (or visitors). Specific chapters of this manual deal with the following subjects: program operational charter, authority, administration, and practices, including interpreting applicable DOE Orders, regulations, and guidance into criteria for in vivo measurement frequency, etc., for the plant-wide whole body counting services; state-of-the-art facilities and equipment used to provide the best in vivo measurement results possible for the approximately 11,000 measurements made annually; procedures for performing the various in vivo measurements at the Whole Body Counter (WBC) and related facilities including whole body counts; operation and maintenance of counting equipment, quality assurance provisions of the program, WBC data processing functions, statistical aspects of in vivo measurements, and whole body counting records and associated guidance documents. 16 refs., 48 figs., 22 tabs.

  2. Spiral Plate Method for Bacterial Determination

    PubMed Central

    Gilchrist, J. E.; Campbell, J. E.; Donnelly, C. B.; Peeler, J. T.; Delaney, J. M.

    1973-01-01

    A method is described for determining the number of bacteria in a solution by the use of a machine which deposits a known volume of sample on a rotating agar plate in an ever decreasing amount in the form of an Archimedes spiral. After the sample is incubated, different colony densities are apparent on the surface of the plate. A modified counting grid is described which relates area of the plate of volume of sample. By counting an appropriate area of the plate, the number of bacteria in the sample is estimated. This method was compared to the pour plate procedure with the use of pure and mixed cultures in water and milk. The results did not demonstrate a significant difference in variance between duplicates at the α = 0.01 level when concentrations of 600 to 12 × 105 bacteria per ml were used, but the spiral plate method gave counts that were higher than counts obtained by the pour plate method. The time and materials required for this method are substantially less than those required for the conventional aerobic pour plate procedure. Images PMID:4632851

  3. High resolution and comprehensive techniques to analyze aerobic methane oxidation in mesocosm experiments

    NASA Astrophysics Data System (ADS)

    Chan, E. W.; Kessler, J. D.; Redmond, M. C.; Shiller, A. M.; Arrington, E. C.; Valentine, D. L.; Colombo, F.

    2015-12-01

    Many studies of microbially mediated aerobic methane oxidation in oceanic environments have examined the many different factors that control the rates of oxidation. However, there is debate on how quickly methane is oxidized once a microbial population is established and what factor(s) are limiting in these types of environments. These factors include the availability of CH4, O2, trace metals, nutrients, and the density of cell population. Limits to these factors can also control the temporal aspects of a methane oxidation event. In order to look at this process in its entirety and with higher temporal resolution, a mesocosm incubation system was developed with a Dissolved Gas Analyzer System (DGAS) coupled with a set of analytical tools to monitor aerobic methane oxidation in real time. With the addition of newer laser spectroscopy techniques (cavity ringdown spectroscopy), stable isotope fractionation caused by microbial processes can also be examined on a real time and automated basis. Cell counting, trace metal, nutrient, and DNA community analyses have also been carried out in conjunction with these mesocosm samples to provide a clear understanding of the biology in methane oxidation dynamics. This poster will detail the techniques involved to provide insights into the chemical and isotopic kinetics controlling aerobic methane oxidation. Proof of concept applications will be presented from seep sites in the Hudson Canyon and the Sleeping Dragon seep field, Mississippi Canyon 118 (MC 118). This system was used to conduct mesocosm experiments to examine methane consumption, O2 consumption, nutrient consumption, and biomass production.

  4. Bacterial vaginosis.

    PubMed Central

    Spiegel, C A

    1991-01-01

    Bacterial vaginosis (BV) is the most common of the vaginitides affecting women of reproductive age. It appears to be due to an alteration in the vaginal ecology by which Lactobacillus spp., the predominant organisms in the healthy vagina, are replaced by a mixed flora including Prevotella bivia, Prevotella disiens, Porphyromonas spp., Mobiluncus spp., and Peptostreptococcus spp. All of these organisms except Mobiluncus spp. are also members of the endogenous vaginal flora. While evidence from treatment trials does not support the notion that BV is sexually transmitted, recent studies have shown an increased risk associated with multiple sexual partners. It has also been suggested that the pathogenesis of BV may be similar to that of urinary tract infections, with the rectum serving as a reservoir for some BV-associated flora. The organisms associated with BV have also been recognized as agents of female upper genital tract infection, including pelvic inflammatory disease, and the syndrome BV has been associated with adverse outcome of pregnancy, including premature rupture of membranes, chorioamnionitis, and fetal loss; postpartum endometritis; cuff cellulitis; and urinary tract infections. The mechanisms by which the BV-associated flora causes the signs of BV are not well understood, but a role for H2O2-producing Lactobacillus spp. in protecting against colonization by catalase-negative anaerobic bacteria has been recognized. These and other aspects of BV are reviewed. PMID:1747864

  5. [Research advances in denitrogenation characteristics of aerobic denitrifiers].

    PubMed

    Liang, Shu-Cheng; Zhao, Min; Lu, Lei; Zhao, Li-Yan

    2010-06-01

    The discovery of aerobic denitrifiers is the enrichment and breakthrough of traditional denitrification theory. Owing to their unique superiority in denitrogenation, aerobic denitrifiers have become a hotspot in the study of bio-denitrogenation of waste water. Under aerobic conditions, the aerobic denitrifiers can utilize organic carbon sources for their growth, and produce N2 from nitrate and nitrite. Most of the denitrifiers can also proceed with heterotrophic nitrification simultaneously, transforming NH4(+)-N to gaseous nitrogen. In this paper, the denitrogenation characteristics and action mechanisms of some isolated aerobic denitrifiers were discussed from the aspects of electron theory and denitrifying enzyme system. The effects of the environmental factors DO, carbon sources, and C/N on the denitrogenation process of aerobic denitrifiers were analyzed, and the screening methods as well as the present and potential applications of aerobic denitrifiers in wastewater treatment were described and discussed. PMID:20873638

  6. In-vitro activity of newer quinolones against aerobic bacteria.

    PubMed

    Auckenthaler, R; Michéa-Hamzehpour, M; Pechère, J C

    1986-04-01

    Nalidixic and five newer 4-quinolones, ciprofloxacin, enoxacin, norfloxacin, ofloxacin and pefloxacin were tested against 576 recent clinical aerobic bacterial isolates. The 4-quinolones were regularly active (MIC90 less than 4 mg/l) against the following bacteria: Staphylococcus aureus, S. epidermidis, S. saprophyticus, different Enterobacteriaceae, Haemophilus influenzae, Campylobacter jejuni, Pseudomonas aeruginosa, Agrobacter spp., Aeromonas spp., Plesiomonas spp., Neisseria meningitidis. Other bacteria were usually intermediately susceptible or resistant: different streptococci, Listeria monocytogenes, Nocardia asteroides, P. maltophilia, Achromobacter xylosoxydans and Alcaligenes denitrificans. Ciprofloxacin was the most potent compound, followed by ofloxacin and pefloxacin, norfloxacin and enoxacin being less active. All the 4-quinolones were much more active than nalidixic acid. The MBC/MIC ratios of the 4-quinolones were between 1 and 2 with a majority of strains, and between 2 and 3 with Streptococcus agalactiae, Str. faecalis and L. monocytogenes. A two- to eight-fold increase of MIC was observed by increasing the inoculum 10,000-fold with most of the strains tested. Susceptible bacterial population of Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens and P. aeruginosa contained more clones resistant to nalidixic acid (10(4) to 10(8) at four times the MIC) than to 4-quinolones (10(5) to 10(9) at four times the MIC). Supplementing the media with MgSO4 produced smaller inhibition zone diameters with a disc diffusion method than those obtained with non-supplemented agar, with all quinolone or strains. Less regular effect, or no effect was obtained after supplementation with ZnSO4 or Ca(NO3)2. PMID:2940214

  7. LINEAR COUNT-RATE METER

    DOEpatents

    Henry, J.J.

    1961-09-01

    A linear count-rate meter is designed to provide a highly linear output while receiving counting rates from one cycle per second to 100,000 cycles per second. Input pulses enter a linear discriminator and then are fed to a trigger circuit which produces positive pulses of uniform width and amplitude. The trigger circuit is connected to a one-shot multivibrator. The multivibrator output pulses have a selected width. Feedback means are provided for preventing transistor saturation in the multivibrator which improves the rise and decay times of the output pulses. The multivibrator is connected to a diode-switched, constant current metering circuit. A selected constant current is switched to an averaging circuit for each pulse received, and for a time determined by the received pulse width. The average output meter current is proportional to the product of the counting rate, the constant current, and the multivibrator output pulse width.

  8. Photon Counting - One More Time

    NASA Astrophysics Data System (ADS)

    Stanton, Richard H.

    2012-05-01

    Photon counting has been around for more than 60 years, and has been available to amateurs for most of that time. In most cases single photons are detected using photomultiplier tubes, "old technology" that became available after the Second World War. But over the last couple of decades the perfection of CCD devices has given amateurs the ability to perform accurate photometry with modest telescopes. Is there any reason to still count photons? This paper discusses some of the strengths of current photon counting technology, particularly relating to the search for fast optical transients. Technology advances in counters and photomultiplier modules are briefly mentioned. Illustrative data are presented including FFT analysis of bright star photometry and a technique for finding optical pulses in a large file of noisy data. This latter technique is shown to enable the discovery of a possible optical flare on the polar variable AM Her.

  9. Higher circulating leukocytes in women with PCOS is reversed by aerobic exercise.

    PubMed

    Covington, Jeffrey D; Tam, Charmaine S; Pasarica, Magdalena; Redman, Leanne M

    2016-05-01

    Polycystic ovary syndrome (PCOS) is characterized by insulin resistance, elevated circulating leukocytes, and hypothesized to have higher adipose tissue inflammation. Aerobic exercise reduces circulating leukocytes and improves insulin sensitivity in obese individuals, but the effect of exercise on inflammation in PCOS is not known. We investigated circulating leukocytes, insulin sensitivity by euglycemic-hyperinsulinemic clamp, serum pro- and anti-inflammatory markers (hsCRP, TNF-α, total and high molecular weight adiponectin), and abdominal subcutaneous adipose tissue (SAT) gene expression of proinflammatory markers in 8 PCOS women and 8 obese control females matched for BMI. Additionally, in a prospective study, the 8 women with PCOS underwent a 16-week aerobic exercise regimen with the same measures performed post-intervention. Compared to controls, white blood cell counts (WBC) were 30% higher (p = 0.04) and circulating total adiponectin levels were 150% lower (p = 0.03) in women with PCOS at baseline/pre-exercise conditions. SAT gene expression of macrophage migration inhibitory factor (MIF, p < 0.01) and interleukin-6 (IL-6, p < 0.05) were also lower in women with PCOS. In response to 16 weeks of aerobic exercise, insulin sensitivity improved (p < 0.01) and WBC counts decreased (p = 0.02). The exercise-induced change in WBC and circulating neutrophils correlated inversely with changes in glucose disposal rate (r = -0.73, p = 0.03; and r = -0.82, p = 0.01, respectively). Aerobic exercise reduced serum leptin (p < 0.05) after 4 weeks, trended to reduce the ratio of leptin-to-high molecular weight adiponectin (p < 0.1) by the 8th week, and significantly increased serum dehydroepiandrosterone sulfate (DHEA-S, p < 0.001) after 16 weeks. In conclusion, women with PCOS have higher circulating leukocytes compared to controls, which can be reversed by aerobic exercise and is associated with improvements in insulin sensitivity. PMID:25446648

  10. Effect of applying lactic acid bacteria and propionic acid on fermentation quality and aerobic stability of oats-common vetch mixed silage on the Tibetan plateau.

    PubMed

    Zhang, Jie; Guo, Gang; Chen, Lei; Li, Junfeng; Yuan, Xianjun; Yu, Chengqun; Shimojo, Masataka; Shao, Tao

    2015-06-01

    The objective of this study was to evaluate effects of lactic acid bacteria and propionic acid on the fermentation quality and aerobic stability of oats-common vetch mixed silage by using a small-scale fermentation system on the Tibetan plateau. (i) An inoculant (Lactobacillus plantarum) (L) or (ii) propionic acid (P) or (iii) inoculant + propionic acid (PL) were used as additives. After fermenting for 60 days, silos were opened and the aerobic stability was tested for the following 15 days. The results showed that all silages were well preserved with low pH and NH3 -N, and high lactic acid content and V-scores. L and PL silages showed higher (P < 0.05) lactic acid and crude protein content than the control silage. P silage inhibited lactic acid production. Under aerobic conditions, L silage had similar yeast counts as the control silage (> 10(5) cfu/g fresh matter (FM)); however, it numerically reduced aerobic stability for 6 h. P and PL silages showed fewer yeasts (< 10(5) cfu/g FM) (P < 0.05) and markedly improved the aerobic stability (> 360 h). The result suggested that PL is the best additive as it could not only improved fermentation quality, but also aerobic stability of oats-common vetch mixed silage on the Tibetan plateau. PMID:25494579

  11. The Effects of Individual PCB Congeners on the Soil Bacterial Community Structure and the Abundance of Biphenyl Dioxygenase Genes

    PubMed Central

    Correa, Paola A.; Lin, LianShin; Just, Craig L.; Hu, Dingfei; Hornbuckle, Keri C.; Schnoor, Jerald L.; Van Aken, Benoit

    2009-01-01

    Polychlorinated biphenyls (PCBs) are toxic environmental contaminants that represent a class of 209 congeners characterized by different degree of chlorination and substitution patterns. Most of experimental studies about microbial degradation of PCBs have been conducted on PCB mixtures, even though evidence accumulated in bacteria and other organisms shows that exposure to different congeners may have different biological effects. Microcosm experiments were conducted using aerobic agitated soil slurries individually exposed to PCB congeners with different degrees of chlorination: PCB-3, 15, 28, and 77, and the commercial mixture Aroclor 1242. After four weeks of incubation, PCBs were analyzed by gas chromatography/mass spectrometry (GC/MS) showing different transformation extents: With the exception of PCB-15 that was not significantly transformed (7%), biodegradation rates decreased with the degree of chlorination, from 75% for PCB-3 to 22% for PCB-77 and Aroclor 1242. The bacterial abundance, as measured by colony counting and 16S rDNA quantification by real-time PCR, was lower (of about 40%) in soil microcosms exposed to the higher-chlorinated congeners, PCB-28, PCB-77, and Aroclor 1242, as compared to non-exposed soils and soils exposed to the lower-chlorinated congeners, PCB-3 and PCB-15. The relative abundance of different taxonomic groups, as determined by real-time PCR, revealed an increase of β-Proteobacteria and Actinobacteria in all microcosms exposed to PCBs, as compared with non-exposed soil. In addition, exposure to PCB-77 and Aroclor 1242 resulted in a higher abundance of α-Proteobacteria and Acidobacteria. Globally, these results suggest that exposure to PCBs (and especially to higher-chlorinated congeners and Aroclor 1242) selected bacterial groups involving most known PCB degraders, i.e., β-Proteobacteria and Acidobacteria. The quantification of biphenyl dioxygenase (BPH) genes - involved in the aerobic degradation of PCBs - using real

  12. Kentucky Kids Count 2001 County Data Book: Families Count.

    ERIC Educational Resources Information Center

    Salley, Valerie

    This Kids Count county data book is the eleventh in a series to measure the well-being of Kentucky's children and focuses on the vital role that families play in ensuring their children's success. Included at the beginning of this document is an executive summary of the databook providing an overview of the statewide data for six child and family…

  13. Effect of Lactobacillus johnsonii CRL1647 on different parameters of honeybee colonies and bacterial populations of the bee gut.

    PubMed

    Audisio, M C; Sabaté, D C; Benítez-Ahrendts, M R

    2015-01-01

    Lactobacillus johnsonii CRL1647, isolated from the intestinal tract of a worker-bee in Salta, Argentina, was delivered to Apis mellifera L. honey bee colonies according to two different administration schedules: 1×10(5) cfu/ml every 15 days (2011) or monthly (2012). The effect of each treatment on the bee-colony performance was monitored by measuring honey production, and the prevalence of varroasis and nosemosis. Worker bees from each assay were randomly captured 3 days after administration and assayed for the following intestinal culturable and defined bacterial populations: total aerobic microorganisms, Bacillus spp. spores, Lactobacillus spp., Enterococcus spp. and enterobacteria. Interestingly, both treatments generated a similar increase in honey production in treated colonies compared to controls: 36.8% (every 15 days) and 36.3% (monthly). Nosema index always exhibited a reduction when lactobacilli were administered; in turn, Varroa incidence was lower when the lactobacilli were administered once a month. Moreover, the administration of L. johnsonii CRL1647 every 15 days produced an increase in the total number of aerobic microorganisms and in bacteria belonging to the genera Lactobacillus and Enterococcus; at the same time, a decrease was observed in the number of total spores at the end of the treatment. The number of enterobacteria was constant and remained below that of control hives at the end of the assay. On the other hand, the delivery of lactobacilli once a month only showed an increase in the number of bacteria belonging to the genus Lactobacillus; meanwhile, viable counts of the remaining microorganisms assayed were reduced. Even though it seems that both treatments were similar, those bee colonies that received L. johnsonii CRL1647 every 15 days became so strong that they swarmed. PMID:25809216

  14. Integrated anaerobic-aerobic process for the biodegradation of chlorinated aromatic compounds

    SciTech Connect

    Armenante, P.M.; Lewandowski, G.; Chengming Kung ); Kafkewitz, D. )

    1992-05-01

    An integrated anaerobic-aerobic process for the complete mineralization of 2,4,6-trichlorophenol was successfully tested and operated. The sludge obtained from the anaerobic digester of a commercial treatment plant was used to obtain an anaerobic consortium capable of partially dechlorinating 2,4,6-trichlorophenol (2,4,6-TCP). The clarified and sterilized effluent from the same anaerobic digester was used as the medium for the anaerobic consortium. During the anaerobic process 2,4,6-TCP was first dechlorinated to 2,4-dichlorophenol and then to 4-chlorophenol (4CP). Stoichiometric amounts of 4-CP were recovered. Similar results were obtained when the anaerobic microorganisms were immobilized on Manville R-635 silica beads. After immobilization, the consortium was able to dechlorinate 150{mu}M of 2,4,6-TCP in four days. Pseudomonas Glathei and an indigenous culture obtained from same sludge used to produce the anaerobic enrichment culture were shown to be able to degrade the 4-CP produced from the anaerobic dechlorination of 2,4,6-TCP. However, for the aerobic 4-CP mineralization to occur the medium had to be buffered with phosphate, since high pH would inhibit the aerobic bacterial activity. It is expected that the proposed approach will be used to treat recalcitrant halogenated compounds that are not amenable to conventional biological treatment.

  15. Comparison of aerobic denitrifying activity among three cultural species with various carbon sources.

    PubMed

    Otani, Y; Hasegawa, K; Hanaki, K

    2004-01-01

    Abilities of three aerobic denitrifiers such as Alcaligenes faecalis, Microvirgula aerodenitrificans and Paracoccus pantotrophus were compared from the viewpoints of nitrate removal efficiency and organic matter utilization. First, the effect of carbon source was investigated. Although nitrate reduction was observed in all strains under aerobic conditions, a change of carbon source considerably affected the denitrification ability. In the case of P. pantotrophus, nitrate and nitrite were completely removed in three days under sodium acetate or leucine as a carbon source. In the case of A. faecalis, sufficient nitrate removal was observed only when sodium acetate or ethanol was added. P. pantotrophus and A. faecalis showed a higher ability of nitrate removal than that of M. aerodenitrificans. Therefore, P. pantotrophus was selected in order to investigate the effects of concentration and repetitive addition of carbon. Sodium acetate was used as a sole carbon source. Nitrate was not reduced when the carbon concentration was below 500 mgC/L. However, when carbon source was added repeatedly, nitrate was reduced under 100 mgC/L after the optical density of the bacterium reached above 1.0. This result indicated that a high enough level of bacterial density was necessary to express aerobic denitrification activity. PMID:15566182

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-08-01

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

  18. Measuring aerobic respiration in stream ecosystems using the resazurin-resorufin system

    NASA Astrophysics Data System (ADS)

    GonzáLez-Pinzón, Ricardo; Haggerty, Roy; Myrold, David D.

    2012-09-01

    The use of smart tracers to study hydrologic systems is becoming more widespread. Smart tracers are compounds that irreversibly react in the presence of a process or condition under investigation. Resazurin (Raz) is a smart tracer that undergoes an irreversible reduction to resorufin (Rru) in the presence of cellular metabolic activity. We quantified the relationship between the transformation of Raz and aerobic bacterial respiration in pure culture experiments using two obligate aerobes and two facultative anaerobes, and in colonized surface and shallow (<10 cm) hyporheic sediments using reach-scale experiments. We found that the transformation of Raz to Rru was nearly perfectly (minr2 = 0.986), positively correlated with aerobic microbial respiration in all experiments. These results suggest that Raz can be used as a surrogate to measure respiration in situ and in vivoat different spatial scales, thus providing an alternative to investigate mechanistic controls of solute transport and stream metabolism on nutrient processing. Lastly, a comparison of respiration and mass-transfer rates in streams suggests that field-scale respiration is controlled by the slower of respiration and mass transfer, highlighting the need to understand both biogeochemistry and physics in stream ecosystems.

  19. Aerobic biodegradation of the brominated flame retardants, dibromoneopentyl glycol and tribromoneopentyl alcohol.

    PubMed

    Segev, Osnat; Meusel, Wolfram; Friedenberger, Melanie; Brenner, Asher; Kushmaro, Ariel

    2009-09-01

    Halogenated organic compounds constitute one of the largest and most diverse groups of chemicals in the environment. Many of these compounds are toxic, persistent and, as a result of their often limited biodegradability, tend to bioaccumulate in the environment. Dibromoneopentyl glycol (DBNPG) and tribromoneopentyl alcohol (TBNPA) are brominated flame retardants commonly used as additives during the manufacture of plastic polymers and as chemical intermediates in the synthesis of other flame retardants. Both are classified as not readily biodegradable. In this paper, we demonstrate the biodegradation of both DBNPG and TBNPA by a common bacterial consortium under aerobic conditions in enrichment cultures containing yeast extract. DBNPG and TBNPA biodegradation is accompanied by a release of bromide into the medium, due to a biological debromination reaction. Molecular analysis of the clone library PCR amplified 16S rRNA gene was used to characterize the bacterial consortium involved in the biodegradation. PMID:19205903

  20. Bacterial tyrosinases.

    PubMed

    Claus, Harald; Decker, Heinz

    2006-01-01

    Tyrosinases are nearly ubiquitously distributed in all domains of life. They are essential for pigmentation and are important factors in wound healing and primary immune response. Their active site is characterized by a pair of antiferromagnetically coupled copper ions, CuA and CuB, which are coordinated by six histidine residues. Such a "type 3 copper centre" is the common feature of tyrosinases, catecholoxidases and haemocycanins. It is also one of several other copper types found in the multi-copper oxidases (ascorbate oxidase, laccase). The copper pair of tyrosinases binds one molecule of atmospheric oxygen to catalyse two different kinds of enzymatic reactions: (1) the ortho-hydroxylation of monophenols (cresolase activity) and (2) the oxidation of o-diphenols to o-diquinones (catecholase activity). The best-known function is the formation of melanins from L-tyrosine via L-dihydroxyphenylalanine (L-dopa). The complicated hydroxylation mechanism at the active centre is still not completely understood, because nothing is known about their tertiary structure. One main reason for this deficit is that hitherto tyrosinases from eukaryotic sources could not be isolated in sufficient quantities and purities for detailed structural studies. This is not the case for prokaryotic tyrosinases from different Streptomyces species, having been intensively characterized genetically and spectroscopically for decades. The Streptomyces tyrosinases are non-modified monomeric proteins with a low molecular mass of ca. 30kDa. They are secreted to the surrounding medium, where they are involved in extracellular melanin production. In the species Streptomyces, the tyrosinase gene is part of the melC operon. Next to the tyrosinase gene (melC2), this operon contains an additional ORF called melC1, which is essential for the correct expression of the enzyme. This review summarizes the present knowledge of bacterial tyrosinases, which are promising models in order to get more insights in

  1. Aerobic workout and bone mass in females.

    PubMed

    Alfredson, H; Nordström, P; Lorentzon, R

    1997-12-01

    This cross-sectional study aimed to investigate bone mass in females participating in aerobic workout. Twenty-three females (age 24.1 +/- 2.7 years), participating in aerobic workout for about 3 hours/week, were compared with 23 age-, weight- and height-matched non-active females. Areal bone mineral density (BMD) was measured in total body, head, whole dominant humerus, lumbar spine, right femoral neck, Ward's triangle, trochanter femoris, in specific sites in right femur diaphysis, distal femur, proximal tibia and tibial diaphysis, and bone mineral content (BMC) was measured in the whole dominant arm and right leg, using dual energy X-ray absorptiometry. The aerobic workout group had significantly (P < 0.05-0.01) higher BMD in total body (3.7%), lumbar spine (7.8%), femoral neck (11.6%), Ward's triangle (11.7%), trochanter femoris (9.6%), proximal tibia (6.8%) and tibia diaphysis (5.9%) compared to the non-active controls. There were no differences between the groups concerning BMD of the whole dominant humerus, femoral diaphysis, distal femur and BMC and lean mass of the whole dominant arm and right leg. Leaness of the whole dominant arm and leg was correlated to BMC of the whole dominant arm and right leg in both groups. In young females, aerobic workout containing alternating high and low impact movements for the lower body is associated with a higher bone mass in clinically important sites like the lumbar spine and hip, but muscle strengthening exercises like push-ups and soft-glove boxing are not associated with a higher bone mass in the dominant humerus. It appears that there is a skeletal adaptation to the loads of the activity. PMID:9458499

  2. Nitrification and aerobic denitrification in anoxic-aerobic sequencing batch reactor.

    PubMed

    Alzate Marin, Juan C; Caravelli, Alejandro H; Zaritzky, Noemí E

    2016-01-01

    The aim of this study was to evaluate the feasibility of achieving nitrogen (N) removal using a lab-scale sequencing batch reactor (SBR) exposed to anoxic/aerobic (AN/OX) phases, focusing to achieve aerobic denitrification. This process will minimize emissions of N2O greenhouse gas. The effects of different operating parameters on the reactor performance were studied: cycle duration, AN/OX ratio, pH, dissolved oxygen concentration (DOC), and organic load. The highest inorganic N removal (NiR), close to 70%, was obtained at pH=7.5, low organic load (440mgCOD/(Lday)) and high aeration given by 12h cycle, AN/OX ratio=0.5:1.0 and DOC higher than 4.0mgO2/L. Nitrification followed by high-rate aerobic denitrification took place during the aerobic phase. Aerobic denitrification could be attributed to Tetrad-forming organisms (TFOs) with phenotype of glycogen accumulating organisms using polyhydroxyalkanoate and/or glycogen storage. The proposed AN/OX system constitutes an eco-friendly N removal process providing N2 as the end product. PMID:26512862

  3. 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%. PMID:17251012

  4. Short communication: Environmental mastitis pathogen counts in freestalls bedded with composted and fresh recycled manure solids.

    PubMed

    Cole, K J; Hogan, J S

    2016-02-01

    An experiment was conducted to compare bacterial counts of environmental mastitis pathogens in composted recycled manure solids bedding with those in fresh recycled manure solids. Eighteen Holstein cows were housed in 1 pen with 18 stalls. One row of 9 freestalls included mattresses and was bedded weekly with composted recycled manure solids. The second row of 9 freestalls included mattresses and was bedded weekly with fresh recycled manure solids. The back one-third of stalls toward the alleyway was covered in 25 to 50 mm of bedding. Samples were taken from the back one-third of 4 stalls for both treatments on d 0, 1, 2, and 6 of each week. After 3 wk, bedding treatments were switched between rows, making the total duration 6 wk. Mean total gram-negative bacterial counts were approximately 0.5 log10 cfu/g of dry matter lower in the composted recycled manure solids on d 0 compared with fresh recycled manure solids. Klebsiella species, coliform, and Streptococcus species counts were at least 1.0 log10 cfu/g of dry matter lower in composted compared with fresh recycled manure solids on d 0. Only gram-negative bacterial counts on d 1 were reduced in composted recycled manure solids compared with fresh recycled manure solids. Differences were not observed between treatments in gram-negative bacterial, coliform, Klebsiella species, or Streptococcus species counts on d 2 and 6. Ash content was higher in composted recycled manure solids compared with fresh recycled manure solids on d 0, 1, 2, and 6. Despite the increase in ash after composting, bacterial counts of mastitis pathogens in composted recycled manure solids were comparable with those in fresh recycled manure when used as freestall bedding. PMID:26709164

  5. Performance and microbial community composition in a long-term sequential anaerobic-aerobic bioreactor operation treating coking wastewater.

    PubMed

    Joshi, Dev Raj; Zhang, Yu; Tian, Zhe; Gao, Yingxin; Yang, Min

    2016-09-01

    The combined anaerobic-aerobic biosystem is assumed to consume less energy for the treatment of high strength industrial wastewater. In this study, pollutant removal performance and microbial diversity were assessed in a long-term (over 300 days) bench-scale sequential anaerobic-aerobic bioreactor treating coking wastewater. Anaerobic treatment removed one third of the chemical oxygen demand (COD) and more than half of the phenols with hydraulic retention time (HRT) of 42 h, while the combined system with total HRT of 114 h removed 81.8, 85.6, 99.9, 98.2, and 85.4 % of COD, total organic carbon (TOC), total phenols, thiocyanate, and cyanide, respectively. Two-dimensional gas chromatography with time-of-flight mass spectrometry showed complete removal of phenol derivatives and nitrogenous heterocyclic compounds (NHCs) via the combined system, with the anaerobic process alone contributing 58.4 and 58.6 % removal on average, respectively. Microbial activity in the bioreactors was examined by 454 pyrosequencing of the bacterial, archaeal, and fungal communities. Proteobacteria (61.2-93.4 %), particularly Betaproteobacteria (34.4-70.1 %), was the dominant bacterial group. Ottowia (14.1-46.7 %), Soehngenia (3.0-8.2 %), and Corynebacterium (0.9-12.0 %), which are comprised of phenol-degrading and hydrolytic bacteria, were the most abundant genera in the anaerobic sludge, whereas Thiobacillus (6.6-43.6 %), Diaphorobacter (5.1-13.0 %), and Comamonas (0.2-11.1 %) were the major degraders of phenol, thiocyanate, and NHCs in the aerobic sludge. Despite the low density of fungi, phenol degrading oleaginous yeast Trichosporon was abundant in the aerobic sludge. This study demonstrated the feasibility and optimization of less energy intensive treatment and the potential association between abundant bacterial groups and biodegradation of key pollutants in coking wastewater. PMID:27221291

  6. Aerobic capacity in wild satin bowerbirds: repeatability and effects of age, sex and condition.

    PubMed

    Chappell, Mark A; Savard, Jean-Francois; Siani, Jennifer; Coleman, Seth W; Keagy, Jason; Borgia, Gerald

    2011-10-01

    Individual variation in aerobic capacity has been extensively studied, especially with respect to condition, maturity or pathogen infection, and to gain insights into mechanistic foundations of performance. However, its relationship to mate competition is less well understood, particularly for animals in natural habitats. We examined aerobic capacity [maximum rate of O2 consumption (VO2,max) in forced exercise] in wild satin bowerbirds, an Australian passerine with a non-resource based mating system and strong intermale sexual competition. We tested for repeatability of mass and VO2,max, differences among age and sex classes, and effects of several condition indices. In adult males, we examined interactions between aerobic performance and bower ownership (required for male mating success). There was significant repeatability of mass and VO2,max within and between years, but between-year repeatability was lower than within-year repeatability. VO2,max varied with an overall scaling to mass(0.791), but most variance in VO2,max was not explained by mass. Indicators of condition (tarsus and wing length asymmetry, the ratio of tarsus length to mass) were not correlated to VO2,max. Ectoparasite counts were weakly correlated to VO2,max across all age-sex classes but not within any class. Adult males, the cohort with the most intense levels of mating competition, had higher VO2,max than juvenile birds or adult females. However, there was no difference between the VO2,max of bower-owning males and that of males not known to hold bowers. Thus one major factor determining male reproductive success was not correlated to aerobic performance. PMID:21900466

  7. Remediation of polychlorinated biphenyl impacted sediment by concurrent bioaugmentation with anaerobic halorespiring and aerobic degrading bacteria

    PubMed Central

    Payne, Rayford B.; Fagervold, Sonja K.; May, Harold D.; Sowers, Kevin R.

    2013-01-01

    Bioremediation of sediments contaminated with commercial PCBs is potentially achievable by the sequential activity of anaerobic halorespiration to convert higher chlorinated congeners to less chlorinated congeners that are susceptible to aerobic respiratory degradation. The efficacy of bioaugmentation with anaerobic halorespiring “Dehalobium chlorocoercia” DF1 and aerobic Burkholderia xenovorans LB400 added concurrently with GAC as a delivery system was determined in 2-liter laboratory mesocosms containing weathered Aroclor-contaminated sediment from Baltimore Harbor, MD. The greatest effect was seen in the mesocosm bioaugmented with both DF1 and LB400 together, which resulted in an 80% decrease by mass of PCBs, from 8 mg/kg to less than 2 mg/kg after 120 days. There was no significant increase in lesser-chlorinated congeners, indicating that both anaerobic dechlorination by DF1 and aerobic degradation by LB400 occurred. In contrast, non-bioaugmented controls containing filtered culture supernatant showed only 25% decrease in total levels of PCBs after 365 days, which was likely due to biostimulation of the indigenous population by the medium. Direct colony counts and molecular analysis targeting a putative reductive dehalogenase gene of D. chlorocoercia, or the bphA gene of LB400 showed the presence of viable DF1 and LB400 in bioaugmented mesocosms after 365 days, indicating that both non-indigenous strains were sustainable within the indigenous microbial community. These results suggest that an in situ treatment employing the simultaneous application of anaerobic and aerobic microorganisms could be an effective, environmentally sustainable strategy to reduce PCBs levels in contaminated sediment. PMID:23463900

  8. Microbiology of the Frankfurter Process: Salmonella and Natural Aerobic Flora

    PubMed Central

    Palumbo, S. A.; Huhtanen, C. N.; Smith, J. L.

    1974-01-01

    Salmonella senftenberg 775W added to frankfurter emulsion was killed during normal processing in the smoke house when internal product temperature was 71.1 C (160 F) or above. The thermal destruction point of S. senftenberg 775W in frankfurters (temperature at which no viable cells were detected) was a function of the length of time of the process rather than of the starting number of cells. Heating of frankfurters to 73.9 C (165 F) substantially reduced the total non-salmonella count. For total non-salmonella bacterial flora and salmonella, relatively little thermal destruction occurred below 43.3 C (110 F). The heating step can bring about a 7-log cycle decrease (108 to 101/g) of bacteria present in the raw emulsion. The flora of this high-bacteriological-count raw emulsion was predominantly gram-negative rods. Variation in the number of bacteria (both total and salmonella) surviving at various temperatures during processing was attributed to slight variations in the temperature pattern of the smoke house during its operation. An integration process was devised which allowed calculation of exposure to temperatures above 110 F (43.3 C) on the basis of degree-minutes. Plots of degree-minutes versus log of surviving bacteria were linear. The salmonella plot had a greater slope than that of the total non-salmonella flora, indicating that salmonellae are more heat sensitive than the bacterial population as a whole. The predominant bacteria surviving the heating step were micrococci. These micrococci were able to increase in number in or on the frankfurters during storage at 5 C. PMID:4596752

  9. Microbiology of the frankfurter process: salmonella and natural aerobic flora.

    PubMed

    Palumbo, S A; Huhtanen, C N; Smith, J L

    1974-04-01

    Salmonella senftenberg 775W added to frankfurter emulsion was killed during normal processing in the smoke house when internal product temperature was 71.1 C (160 F) or above. The thermal destruction point of S. senftenberg 775W in frankfurters (temperature at which no viable cells were detected) was a function of the length of time of the process rather than of the starting number of cells. Heating of frankfurters to 73.9 C (165 F) substantially reduced the total non-salmonella count. For total non-salmonella bacterial flora and salmonella, relatively little thermal destruction occurred below 43.3 C (110 F). The heating step can bring about a 7-log cycle decrease (10(8) to 10(1)/g) of bacteria present in the raw emulsion. The flora of this high-bacteriological-count raw emulsion was predominantly gram-negative rods. Variation in the number of bacteria (both total and salmonella) surviving at various temperatures during processing was attributed to slight variations in the temperature pattern of the smoke house during its operation. An integration process was devised which allowed calculation of exposure to temperatures above 110 F (43.3 C) on the basis of degree-minutes. Plots of degree-minutes versus log of surviving bacteria were linear. The salmonella plot had a greater slope than that of the total non-salmonella flora, indicating that salmonellae are more heat sensitive than the bacterial population as a whole. The predominant bacteria surviving the heating step were micrococci. These micrococci were able to increase in number in or on the frankfurters during storage at 5 C. PMID:4596752

  10. Shakespeare Live! and Character Counts.

    ERIC Educational Resources Information Center

    Brookshire, Cathy A.

    This paper discusses a live production of Shakespeare's "Macbeth" (in full costume but with no sets) for all public middle school and high school students in Harrisonburg and Rockingham, Virginia. The paper states that the "Character Counts" issues that are covered in the play are: decision making, responsibility and citizenship, trustworthiness,…

  11. Meal Counting and Claiming Manual.

    ERIC Educational Resources Information Center

    Food and Nutrition Service (USDA), Washington, DC.

    This manual contains information about the selection and implementation of a meal counting and claiming system for the National School Lunch Program (NSLP) and the School Breakfast Program (BSP). Federal reimbursement is provided for each meal that meets program requirements and is served to an eligible student. Part 1 explains the six elements of…

  12. What Really Counts in Schools.

    ERIC Educational Resources Information Center

    Eisner, Elliot W.

    1991-01-01

    Brains are biological, but minds are cultural achievements. What really counts in schools is teaching children the excitement of exploring ideas, helping youngsters formulate their own problems and resolution strategies, developing multiple literacy forms, imparting the importance of wonder, creating a sense of community, and recognizing each…

  13. South Carolina Kids Count, 2000.

    ERIC Educational Resources Information Center

    Holmes, A. Baron

    This Kids Count report examines statewide trends in the well-being of South Carolina's children. The statistical portrait is based on 41 indicators in the areas of demographics, family, economic status, health, readiness and early school performance, scholastic achievement, and adolescent risk behaviors. The indicators are: (1) population; (2)…

  14. Oklahoma Kids Count Factbook, 2002.

    ERIC Educational Resources Information Center

    Ingraham, Sandy

    This Kids Count Factbook details county and statewide trends in the well-being of children in Oklahoma. The statistical portrait is based on seven indicators or benchmarks of child well-being: (1) low birthweight infants; (2) infant mortality; (3) births to young teens; (4) child abuse and neglect; (5) child and teen death; (6) high school…

  15. On Counting the Rational Numbers

    ERIC Educational Resources Information Center

    Almada, Carlos

    2010-01-01

    In this study, we show how to construct a function from the set N of natural numbers that explicitly counts the set Q[superscript +] of all positive rational numbers using a very intuitive approach. The function has the appeal of Cantor's function and it has the advantage that any high school student can understand the main idea at a glance…

  16. KIDS COUNT New Hampshire, 2000.

    ERIC Educational Resources Information Center

    Shemitz, Elllen, Ed.

    This Kids Count report presents statewide trends in the well-being of New Hampshire's children. The statistical report is based on 22 indicators of child well-being in 5 interrelated areas: (1) children and families (including child population, births, children living with single parent, and children experiencing parental divorce); (2) economic…

  17. Automatic Crater Counts on Mars

    NASA Astrophysics Data System (ADS)

    Plesko, C.; Brumby, S.; Asphaug, E.; Chamberlain, D.; Engel, T.

    2004-03-01

    We present results of an automated crater counting technique for THEMIS data. Algorithms were developed using GENIE machine learning software. The technique detects craters, generalizes well to new data, and is used to rapidly produce R-plots and statistical data.

  18. Carbon fiber counting. [aircraft structures

    NASA Technical Reports Server (NTRS)

    Pride, R. A.

    1980-01-01

    A method was developed for characterizing the number and lengths of carbon fibers accidentally released by the burning of composite portions of civil aircraft structure in a jet fuel fire after an accident. Representative samplings of carbon fibers collected on transparent sticky film were counted from photographic enlargements with a computer aided technique which also provided fiber lengths.

  19. Wiskids Count Data Book, 2003.

    ERIC Educational Resources Information Center

    Cranley, M. Martha; Bianchi, J. P.; Eleson, Charity; Hall, Linda; Jacobson, Bob; Jackson, Kristin; Peacock, Jon

    This WisKids Count data book provides a statistical portrait of the well-being of Wisconsin's children. In addition to demographic data indicating changing communities, the indicators and data are organized into five overarching goals: (1) Healthy Families and Children Thrive, including births to single women, infant deaths, and health care…

  20. South Carolina Kids Count, 2001.

    ERIC Educational Resources Information Center

    Holmes, A. Baron

    This Kids Count report examines statewide trends in the well-being of South Carolina's children. The statistical portrait is based on 42 indicators in the areas of demographics, family, economic status, health, readiness and early school performance, scholastic achievement, and adolescent risk behaviors. The indicators are: (1) population; (2)…

  1. KIDS COUNT Data Brief, 2009

    ERIC Educational Resources Information Center

    Annie E. Casey Foundation, 2009

    2009-01-01

    This 2009 KIDS COUNT Data Brief features highlights of the enhanced, mobile-friendly Data Center; data on the 10 key indicators of child well-being for all U.S. states, the District of Columbia, and many cities, counties, and school districts; and a summary of this year's essay, which calls for improvements to the nation's ability to design and…

  2. Counting a Culture of Mealworms

    ERIC Educational Resources Information Center

    Ashbrook, Peggy

    2007-01-01

    Math is not the only topic that will be discussed when young children are asked to care for and count "mealworms," a type of insect larvae (just as caterpillars are the babies of butterflies, these larvae are babies of beetles). The following activity can take place over two months as the beetles undergo metamorphosis from larvae to adults. As the…

  3. Kids Count in Colorado! 2003.

    ERIC Educational Resources Information Center

    Boeke, Kaye

    This Kids Count report examines state, county, and regional trends in the well-being of Colorado's children. The first part of the report is presented in four chapters. Chapter 1 includes findings regarding the increasing diversity of the child population, linguistic isolation, the impact of parental unemployment, child poverty, and the affordable…

  4. Verbal Counting in Bilingual Contexts

    ERIC Educational Resources Information Center

    Donevska-Todorova, Ana

    2015-01-01

    Informal experiences in mathematics often include playful competitions among young children in counting numbers in as many as possible different languages. Can these enjoyable experiences result with excellence in the formal processes of education? This article discusses connections between mathematical achievements and natural languages within…

  5. Kids Count Data Sheet, 2000.

    ERIC Educational Resources Information Center

    Annie E. Casey Foundation, Baltimore, MD.

    Data from the 50 United States are listed for 1997 from Kids Count in an effort to track state-by-state the status of children in the United States and to secure better futures for all children. Data include percent low birth weight babies; infant mortality rate; child death rate; rate of teen deaths by accident, homicide, and suicide; teen birth…

  6. Oklahoma Kids Count Factbook '96.

    ERIC Educational Resources Information Center

    Ingraham, Sandy

    This data book presents findings of the Kids Count Project on current conditions faced by Oklahoma children age birth through 18. This second annual factbook organizes state and county data over a period of time to enable conditions for children in each county to be compared and ranked. The benchmark indicators studied include low birthweight…

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

    PubMed Central

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

    2014-01-01

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

  8. Effects of maximum intensity aerobic swimming exercise until exhaustion at different times of day on the hematological parameters in rats.

    PubMed

    Beck, W; Gobatto, Claudio Alexandre

    2013-12-01

    The aims of this study were: a) to analyze the time of day effect on the aerobic capacity and time to exhaustion at aerobic capacity intensity (TE), and b) to analyze the physiological impact of handling and exercise testing during the light and dark periods, based on hematological parameters. Eighty rats were randomly divided into two control groups (C12 and C20) and two exercise groups (E12 and E20), assessed at 12:00 h (C12 and E12) or 20:00 h (C20 and E20). The lactate minimum intensity (LMi) was measured and after 48 h the exercise groups were subjected to a bout of swimming until exhaustion at LMi (TE). The TE was 1.30 ± 0.51 h for the E12 group and 1.81 ± 0.77 h for the E20 group (p = 0.03). The time of day effect was significant for all white blood cell counts (12:00 h > 20:00 h). Chronic handling and performing exercise tests at 12:00 h (light period) resulted in an increased WBC counts and decreased exercise tolerance. The favorable time of day for aerobic capacity and performance assessment and hematological parameters was at 20:00 h (dark period), which is associated with the wakefulness period of the assessed animals. PMID:24013943

  9. 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

  10. Bacterial differentiation.

    PubMed

    Shapiro, L; Agabian-Keshishian, N; Bendis, I

    1971-09-01

    technique can be used to select for mutants blocked in the various stages of morphogenesis. 3) Temperature-sensitive mutants of Caulobacter that are restricted in macromolecular synthesis and development at elevated temperatures have been isolated. 4) Genetic exchange in the Calflobacter genus has been demonstrated and is now being defined. Two questions related to control processes can now readily be approached experimentally. (i) Is the temporal progression of events occurring during bacterial differentiation controlled by regulator gene products? (ii) Is the differentiation cycle like a biosynthetic pathway where one event must follow another? The availability of temperature-sensitive mutants blocked at various stages of development permits access to both questions. An interesting feature of the differentiation cycle is that the polar organelle may represent a special segregated unit which is operative in the control of the differentiation process. Perhaps the sequential morphogenic changes exhibited by Caulobacter are dependent on the initial synthesis of this organelle. Because the ultimate expression of cell changes are dependent on selective protein synthesis, specific messenger RNA production-either from DNA present in an organelle or from the chromosome-may prove to be a controlling factor in cell differentiation. We have begun studies with RNA polymerase purified from Caulobacter crescentus to determine whether cell factors or alterations in the enzyme structure serve to change the specificity of transcription during the cell cycle. Control of sequential cell changes at the level of transcription has long been postulated and has recently been substantiated in the case of Bacillus sporulation (6). The Caulobacter bacteria now present another system in which direct analysis of these control mechanisms is feasible. PMID:5572165

  11. The emission of volatile compounds during the aerobic and the combined anaerobic/aerobic composting of biowaste

    NASA Astrophysics Data System (ADS)

    Smet, Erik; Van Langenhove, Herman; De Bo, Inge

    Two different biowaste composting techniques were compared with regard to their overall emission of volatile compounds during the active composting period. In the aerobic composting process, the biowaste was aerated during a 12-week period, while the combined anaerobic/aerobic composting process consisted of a sequence of a 3-week anaerobic digestion (phase I) and a 2-week aeration period (phase II). While the emission of volatiles during phase I of the combined anaerobic/aerobic composting process was measured in a full-scale composting plant, the aerobic stages of both composting techniques were performed in pilot-scale composting bins. Similar groups of volatile compounds were analysed in the biogas and the aerobic composting waste gases, being alcohols, carbonyl compounds, terpenes, esters, sulphur compounds and ethers. Predominance of alcohols (38% wt/wt of the cumulative emission) was observed in the exhaust air of the aerobic composting process, while predominance of terpenes (87%) and ammonia (93%) was observed in phases I and II of the combined anaerobic/aerobic composting process, respectively. In the aerobic composting process, 2-propanol, ethanol, acetone, limonene and ethyl acetate made up about 82% of the total volatile organic compounds (VOC)-emission. Next to this, the gas analysis during the aerobic composting process revealed a strong difference in emission profile as a function of time between different groups of volatiles. The total emission of VOC, NH 3 and H 2S during the aerobic composting process was 742 g ton -1 biowaste, while the total emission during phases I and II of the combined anaerobic/aerobic composting process was 236 and 44 g ton -1 biowaste, respectively. Taking into consideration the 99% removal efficiency of volatiles upon combustion of the biogas of phase I in the electricity generator, the combined anaerobic/aerobic composting process can be considered as an attractive alternative for aerobic biowaste composting because of

  12. The aerobic and anaerobic bacteriology of perirectal abscesses.

    PubMed Central

    Brook, I; Frazier, E H

    1997-01-01

    The microbiology of perirectal abscesses in 144 patients was studied. Aerobic or facultative bacteria only were isolated in 13 (9%) instances, anaerobic bacteria only were isolated in 27 (19%) instances, and mixed aerobic and anaerobic flora were isolated in 104 (72%) instances. A total of 325 anaerobic and 131 aerobic or facultative isolates were recovered (2.2 anaerobic isolates and 0.9 aerobic isolates per specimen). The predominant anaerobes were as follows: Bacteroides fragilis group (85 isolates), Peptostreptococcus spp. (72 isolates), Prevotella spp. (71 isolates), Fusobacterium spp. (21 isolates), Porphyromonas spp. (20 isolates), and Clostridium spp. (15 isolates). The predominant aerobic and facultative bacteria were as follows: Staphylococcus aureus (34 isolates), Streptococcus spp. (28 isolates), and Escherichia coli (19 isolates). These data illustrate the polymicrobial aerobic and anaerobic microbiology of perirectal abscesses. PMID:9350771

  13. Improved RDX detoxification with starch addition using a novel nitrogen-fixing aerobic microbial consortium from soil contaminated with explosives.

    PubMed

    Khan, Muhammad Imran; Yang, Jihoon; Yoo, Byungun; Park, Joonhong

    2015-04-28

    In this work, we developed and characterized a novel nitrogen-fixing aerobic microbial consortium for the complete detoxification of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). Aerobic RDX biodegradation coupled with microbial growth and nitrogen fixation activity were effectively stimulated by the co-addition of starch and RDX under nitrogen limiting conditions. In the starch-stimulated nitrogen-fixing RDX degradative consortium, the RDX degradation activity was correlated with the xplA and nifH gene copy numbers, suggesting the involvement of nitrogen fixing populations in RDX biodegradation. Formate, nitrite, nitrate, and ammonia were detected as aerobic RDX degradation intermediates without the accumulation of any nitroso-derivatives or NDAB (4-nitro-2,4-diazabutanal), indicating nearly complete mineralization. Pyrosequencing targeting the bacterial 16S rRNA genes revealed that the Rhizobium, Rhizobacter and Terrimonas population increased as the RDX degradation activity increased, suggesting their involvement in the degradation process. These findings imply that the nitrogen-fixing aerobic RDX degrading consortium is a valuable microbial resource for improving the detoxification of RDX-contaminated soil or groundwater, especially when combined with rhizoremediation. PMID:25661171

  14. Application of potential phosphate-solubilizing bacteria and organic acids on phosphate solubilization from phosphate rock in aerobic rice.

    PubMed

    Panhwar, Qurban Ali; Jusop, Shamshuddin; Naher, Umme Aminun; Othman, Radziah; Razi, Mohd Ismail

    2013-01-01

    A study was conducted at Universiti Putra Malaysia to determine the effect of phosphate-solubilizing bacteria (PSB) and organic acids (oxalic & malic) on phosphate (P) solubilization from phosphate rock (PR) and growth of aerobic rice. Four rates of each organic acid (0, 10, 20, and 30 mM), and PSB strain (Bacillus sp.) were applied to aerobic rice. Total bacterial populations, amount of P solubilization, P uptake, soil pH, and root morphology were determined. The results of the study showed significantly high P solubilization in PSB with organic acid treatments. Among the two organic acids, oxalic acid was found more effective compared to malic acid. Application of oxalic acid at 20 mM along with PSB16 significantly increased soluble soil P (28.39 mg kg(-1)), plant P uptake (0.78 P pot(-1)), and plant biomass (33.26 mg). Addition of organic acids with PSB and PR had no influence on soil pH during the planting period. A higher bacterial population was found in rhizosphere (8.78 log10 cfu g(-1)) compared to the nonrhizosphere and endosphere regions. The application of organic acids along with PSB enhanced soluble P in the soil solution, improved root growth, and increased plant biomass of aerobic rice seedlings without affecting soil pH. PMID:24288473

  15. Imaging by terahertz photon counting

    NASA Astrophysics Data System (ADS)

    Ikushima, Kenji; Komiyama, Susumu

    2010-08-01

    Photon counting method is indispensable in visible/near-infrared optical measurements for detecting extremely weak radiation. The method, however, has been inaccessible in terahertz region, where the photon energies are more than 100 times smaller and catching individual photons is difficult. Here we review photon counting measurements of terahertz waves, by incorporating a semiconductor quantum-dot terahertz-photon detector into a scanning terahertz microscope. By using a quantum Hall effect detector as well, measurements cover the intensity dynamic range more than six orders of magnitude. Applying the measurement system to the study of semiconductor quantum Hall effect devices, we image extremely weak cyclotron radiation emitted by nonequilibrium electrons. Owing to the unprecedented sensitivity, a variety of new features of electron kinetics are unveiled. Besides semiconductor electric devices studied here, the experimental method will find application in diverse areas of molecular dynamics, microthermography, and cell activities.

  16. Bayesian Kernel Mixtures for Counts

    PubMed Central

    Canale, Antonio; Dunson, David B.

    2011-01-01

    Although Bayesian nonparametric mixture models for continuous data are well developed, there is a limited literature on related approaches for count data. A common strategy is to use a mixture of Poissons, which unfortunately is quite restrictive in not accounting for distributions having variance less than the mean. Other approaches include mixing multinomials, which requires finite support, and using a Dirichlet process prior with a Poisson base measure, which does not allow smooth deviations from the Poisson. As a broad class of alternative models, we propose to use nonparametric mixtures of rounded continuous kernels. An efficient Gibbs sampler is developed for posterior computation, and a simulation study is performed to assess performance. Focusing on the rounded Gaussian case, we generalize the modeling framework to account for multivariate count data, joint modeling with continuous and categorical variables, and other complications. The methods are illustrated through applications to a developmental toxicity study and marketing data. This article has supplementary material online. PMID:22523437

  17. Bayesian Kernel Mixtures for Counts.

    PubMed

    Canale, Antonio; Dunson, David B

    2011-12-01

    Although Bayesian nonparametric mixture models for continuous data are well developed, there is a limited literature on related approaches for count data. A common strategy is to use a mixture of Poissons, which unfortunately is quite restrictive in not accounting for distributions having variance less than the mean. Other approaches include mixing multinomials, which requires finite support, and using a Dirichlet process prior with a Poisson base measure, which does not allow smooth deviations from the Poisson. As a broad class of alternative models, we propose to use nonparametric mixtures of rounded continuous kernels. An efficient Gibbs sampler is developed for posterior computation, and a simulation study is performed to assess performance. Focusing on the rounded Gaussian case, we generalize the modeling framework to account for multivariate count data, joint modeling with continuous and categorical variables, and other complications. The methods are illustrated through applications to a developmental toxicity study and marketing data. This article has supplementary material online. PMID:22523437

  18. 1/Nc Countings in Baryons

    SciTech Connect

    Jose Goity

    2004-05-01

    The 1/N{sub c} power countings for baryon decays and configuration mixings are determined by means of a non-relativistic quark picture. Such countings are expected to be robust as the quark masses are decreased towards the chiral limit. It is shown that excited baryons have natural widths of {Omicron}(N{sub c}{sup 0}). These dominant widths are due to the decays that proceed directly to the ground state baryons, with cascade decays being suppressed to {Omicron}(1/N{sub c}). Configuration mixings, defined as mixings between states belonging to different O(3) x SU(2N{sub f}) multiplets, are shown to be sub-leading in an expansion in 1/{radical}N{sub c}, except for certain mixings between excited multiplets belonging to the mixed-symmetric spin-flavor representation and different O(3) representations, where the mixings are of zeroth order in 1/N{sub c}.

  19. Stability of fringe counting interferometers

    NASA Technical Reports Server (NTRS)

    Edgerton, J. W.; Andrew, K. L.

    1974-01-01

    Two configurations of an automatic bidirectional, fringe-counting corner-cube interferometer are compared. They differ only in the method of quadrature phase introduction. The one using polarization coding has good phase stability at optical path differences as large as 955 mm, the one using adjacent beams has such poor phase stability as to render it useless at path differences greater than 700 mm. A useful well-defined alignment procedure is given for the corner-cube interferometer.

  20. Approximate Counting of Graphical Realizations

    PubMed Central

    2015-01-01

    In 1999 Kannan, Tetali and Vempala proposed a MCMC method to uniformly sample all possible realizations of a given graphical degree sequence and conjectured its rapidly mixing nature. Recently their conjecture was proved affirmative for regular graphs (by Cooper, Dyer and Greenhill, 2007), for regular directed graphs (by Greenhill, 2011) and for half-regular bipartite graphs (by Miklós, Erdős and Soukup, 2013). Several heuristics on counting the number of possible realizations exist (via sampling processes), and while they work well in practice, so far no approximation guarantees exist for such an approach. This paper is the first to develop a method for counting realizations with provable approximation guarantee. In fact, we solve a slightly more general problem; besides the graphical degree sequence a small set of forbidden edges is also given. We show that for the general problem (which contains the Greenhill problem and the Miklós, Erdős and Soukup problem as special cases) the derived MCMC process is rapidly mixing. Further, we show that this new problem is self-reducible therefore it provides a fully polynomial randomized approximation scheme (a.k.a. FPRAS) for counting of all realizations. PMID:26161994

  1. Approximate Counting of Graphical Realizations.

    PubMed

    Erdős, Péter L; Kiss, Sándor Z; Miklós, István; Soukup, Lajos

    2015-01-01

    In 1999 Kannan, Tetali and Vempala proposed a MCMC method to uniformly sample all possible realizations of a given graphical degree sequence and conjectured its rapidly mixing nature. Recently their conjecture was proved affirmative for regular graphs (by Cooper, Dyer and Greenhill, 2007), for regular directed graphs (by Greenhill, 2011) and for half-regular bipartite graphs (by Miklós, Erdős and Soukup, 2013). Several heuristics on counting the number of possible realizations exist (via sampling processes), and while they work well in practice, so far no approximation guarantees exist for such an approach. This paper is the first to develop a method for counting realizations with provable approximation guarantee. In fact, we solve a slightly more general problem; besides the graphical degree sequence a small set of forbidden edges is also given. We show that for the general problem (which contains the Greenhill problem and the Miklós, Erdős and Soukup problem as special cases) the derived MCMC process is rapidly mixing. Further, we show that this new problem is self-reducible therefore it provides a fully polynomial randomized approximation scheme (a.k.a. FPRAS) for counting of all realizations. PMID:26161994

  2. Applications of bacterial cellulose and its composites in biomedicine.

    PubMed

    Rajwade, J M; Paknikar, K M; Kumbhar, J V

    2015-03-01

    Bacterial cellulose produced by few but specific microbial genera is an extremely pure natural exopolysaccharide. Besides providing adhesive properties and a competitive advantage to the cellulose over-producer, bacterial cellulose confers UV protection, ensures maintenance of an aerobic environment, retains moisture, protects against heavy metal stress, etc. This unique nanostructured matrix is being widely explored for various medical and nonmedical applications. It can be produced in various shapes and forms because of which it finds varied uses in biomedicine. The attributes of bacterial cellulose such as biocompatibility, haemocompatibility, mechanical strength, microporosity and biodegradability with its unique surface chemistry make it ideally suited for a plethora of biomedical applications. This review highlights these qualities of bacterial cellulose in detail with emphasis on reports that prove its utility in biomedicine. It also gives an in-depth account of various biomedical applications ranging from implants and scaffolds for tissue engineering, carriers for drug delivery, wound-dressing materials, etc. that are reported until date. Besides, perspectives on limitations of commercialisation of bacterial cellulose have been presented. This review is also an update on the variety of low-cost substrates used for production of bacterial cellulose and its nonmedical applications and includes patents and commercial products based on bacterial cellulose. PMID:25666681

  3. Sequence-Based Identification of Aerobic Actinomycetes

    PubMed Central

    Patel, Jean Baldus; Wallace, Richard J.; Brown-Elliott, Barbara A.; Taylor, Tony; Imperatrice, Carol; Leonard, Deborah G. B.; Wilson, Rebecca W.; Mann, Linda; Jost, Kenneth C.; Nachamkin, Irving

    2004-01-01

    We investigated the utility of 500-bp 16S rRNA gene sequencing for identifying clinically significant species of aerobic actinomycetes. A total of 28 reference strains and 71 clinical isolates that included members of the genera Streptomyces, Gordonia, and Tsukamurella and 10 taxa of Nocardia were studied. Methods of nonsequencing analyses included growth and biochemical analysis, PCR-restriction enzyme analysis of the 439-bp Telenti fragment of the 65 hsp gene, susceptibility testing, and, for selected isolates, high-performance liquid chromatography. Many of the isolates were included in prior taxonomic studies. Sequencing of Nocardia species revealed that members of the group were generally most closely related to the American Type Culture Collection (ATCC) type strains. However, the sequences of Nocardia transvalensis, N. otitidiscaviarum, and N. nova isolates were highly variable; and it is likely that each of these species contains multiple species. We propose that these three species be designated complexes until they are more taxonomically defined. The sequences of several taxa did not match any recognized species. Among other aerobic actinomycetes, each group most closely resembled the associated reference strain, but with some divergence. The study demonstrates the ability of partial 16S rRNA gene sequencing to identify members of the aerobic actinomycetes, but the study also shows that a high degree of sequence divergence exists within many species and that many taxa within the Nocardia spp. are unnamed at present. A major unresolved issue is the type strain of N. asteroides, as the present one (ATCC 19247), chosen before the availability of molecular analysis, does not represent any of the common taxa associated with clinical nocardiosis. PMID:15184431

  4. Aerobic degradation of olive mill wastewaters.

    PubMed

    Benitez, J; Beltran-Heredia, J; Torregrosa, J; Acero, J L; Cercas, V

    1997-02-01

    The degradation of olive mill wastewater by aerobic microorganisms has been investigated in a batch reactor, by conducting experiments where the initial concentration of organic matter, quantified by the chemical oxygen demand, and the initial biomass were varied. The evolution of the chemical oxygen demand, biomass and the total contents of phenolic and aromatic compounds were followed through each experiment. According to the Contois model, a kinetic expression for the substrate utilization rate is derived, and its biokinetic constants are evaluated. This final predicted equation agrees well with all the experimental data. PMID:9077005

  5. [Heterotrophic Nitrification and Aerobic Denitrification of the Hypothermia Aerobic Denitrification Bacterium: Arthrobacter arilaitensis].

    PubMed

    He, Teng-xia; Ni, Jiu-pai; Li, Zhen-lun; Sun, Quan; Ye Qing; Xu, Yi

    2016-03-15

    High concentrations of ammonium, nitrate and nitrite nitrogen were employed to clarify the abilities of heterotrophic nitrification and aerobic denitrification of Arthrobacter arilaitensis strain Y-10. Meanwhile, by means of inoculating the strain suspension into the mixed ammonium and nitrate, ammonium and nitrite nitrogen simulated wastewater, we studied the simultaneous nitrification and denitrification ability of Arthrobacter arilaitensis strain Y-10. In addition, cell optical density was assayed in each nitrogen removal process to analyze the relationship of cell growth and nitrogen removal efficiency. The results showed that the hypothermia denitrification strain Arthrobacter arilaitensis Y-10 exhibited high nitrogen removal efficiency during heterotrophic nitrification and aerobic denitrification. The ammonium, nitrate and nitrite removal rates were 65.0%, 100% and 61.2% respectively when strain Y-10 was cultivated for 4 d at 15°C with initial ammonium, nitrate and nitrite nitrogen concentrations of 208.43 mg · L⁻¹, 201.16 mg · L⁻¹ and 194.33 mg · L⁻¹ and initial pH of 7.2. Nitrite nitrogen could only be accumulated in the medium containing nitrate nitrogen during heterotrophic nitrification and aerobic denitrification process. Additionally, the ammonium nitrogen was mainly removed in the inorganic nitrogen mixed synthetic wastewater. In short, Arthrobacter arilaitensis Y-10 could conduct nitrification and denitrification effectively under aerobic condition and the ammonium nitrogen removal rate was more than 80.0% in the inorganic nitrogen mixed synthetic wastewater. PMID:27337904

  6. What I Need to Know about Carbohydrate Counting and Diabetes

    MedlinePlus

    ... URL Español What I need to know about Carbohydrate Counting and Diabetes Page Content On this page: ... counting? Points to Remember Clinical Trials What is carbohydrate counting? Carbohydrate * counting, also called carb counting, is ...

  7. Microbial Air Quality and Bacterial Surface Contamination in Ambulances During Patient Services

    PubMed Central

    Luksamijarulkul, Pipat; Pipitsangjan, Sirikun

    2015-01-01

    Objectives We sought to assess microbial air quality and bacterial surface contamination on medical instruments and the surrounding areas among 30 ambulance runs during service. Methods We performed a cross-sectional study of 106 air samples collected from 30 ambulances before patient services and 212 air samples collected during patient services to assess the bacterial and fungal counts at the two time points. Additionally, 226 surface swab samples were collected from medical instrument surfaces and the surrounding areas before and after ambulance runs. Groups or genus of isolated bacteria and fungi were preliminarily identified by Gram’s stain and lactophenol cotton blue. Data were analyzed using descriptive statistics, t-test, and Pearson’s correlation coefficient with a p-value of less than 0.050 considered significant. Results The mean and standard deviation of bacterial and fungal counts at the start of ambulance runs were 318±485cfu/m3 and 522±581cfu/m3, respectively. Bacterial counts during patient services were 468±607cfu/m3 and fungal counts were 656±612cfu/m3. Mean bacterial and fungal counts during patient services were significantly higher than those at the start of ambulance runs, p=0.005 and p=0.030, respectively. For surface contamination, the overall bacterial counts before and after patient services were 0.8±0.7cfu/cm2 and 1.3±1.1cfu/cm2, respectively (p<0.001). The predominant isolated bacteria and fungi were Staphylococcus spp. and Aspergillus spp., respectively. Additionally, there was a significantly positive correlation between bacterial (r=0.3, p<0.010) and fungal counts (r=0.2, p=0.020) in air samples and bacterial counts on medical instruments and allocated areas. Conclusions This study revealed high microbial contamination (bacterial and fungal) in ambulance air during services and higher bacterial contamination on medical instrument surfaces and allocated areas after ambulance services compared to the start of ambulance runs

  8. Alleviating Cancer Drug Toxicity by Inhibiting a Bacterial Enzyme

    SciTech Connect

    Wallace, Bret D.; Wang, Hongwei; Lane, Kimberly T.; Scott, John E.; Orans, Jillian; Koo, Ja Seol; Venkatesh, Madhukumar; Jobin, Christian; Yeh, Li-An; Mani, Sridhar; Redinbo, Matthew R.

    2011-08-12

    The dose-limiting side effect of the common colon cancer chemotherapeutic CPT-11 is severe diarrhea caused by symbiotic bacterial {beta}-glucuronidases that reactivate the drug in the gut. We sought to target these enzymes without killing the commensal bacteria essential for human health. Potent bacterial {beta}-glucuronidase inhibitors were identified by high-throughput screening and shown to have no effect on the orthologous mammalian enzyme. Crystal structures established that selectivity was based on a loop unique to bacterial {beta}-glucuronidases. Inhibitors were highly effective against the enzyme target in living aerobic and anaerobic bacteria, but did not kill the bacteria or harm mammalian cells. Finally, oral administration of an inhibitor protected mice from CPT-11-induced toxicity. Thus, drugs may be designed to inhibit undesirable enzyme activities in essential microbial symbiotes to enhance chemotherapeutic efficacy.

  9. Low white blood cell count and cancer

    MedlinePlus

    Neutropenia and cancer; Absolute neutrophil count and cancer; ANC and cancer ... A person with cancer can get a low white blood cell count from the cancer or from treatment for the cancer. Cancer may ...

  10. Acute effects of aerobic exercise promote learning.

    PubMed

    Perini, Renza; Bortoletto, Marta; Capogrosso, Michela; Fertonani, Anna; Miniussi, Carlo

    2016-01-01

    The benefits that physical exercise confers on cardiovascular health are well known, whereas the notion that physical exercise can also improve cognitive performance has only recently begun to be explored and has thus far yielded only controversial results. In the present study, we used a sample of young male subjects to test the effects that a single bout of aerobic exercise has on learning. Two tasks were run: the first was an orientation discrimination task involving the primary visual cortex, and the second was a simple thumb abduction motor task that relies on the primary motor cortex. Forty-four and forty volunteers participated in the first and second experiments, respectively. We found that a single bout of aerobic exercise can significantly facilitate learning mechanisms within visual and motor domains and that these positive effects can persist for at least 30 minutes following exercise. This finding suggests that physical activity, at least of moderate intensity, might promote brain plasticity. By combining physical activity-induced plasticity with specific cognitive training-induced plasticity, we favour a gradual up-regulation of a functional network due to a steady increase in synaptic strength, promoting associative Hebbian-like plasticity. PMID:27146330

  11. Characterization and aerobic biodegradation of selected monoterpenes

    SciTech Connect

    Misra, G.; Pavlostathis, S.G.; Li, J.; Purdue, E.M.

    1996-12-31

    Monoterpenes are biogenic chemicals and occur in abundance in nature. Large-scale industrial use of these chemicals has recently been initiated in an attempt to replace halogenated solvents and chlorofluorocarbons which have been implicated in the stratospheric depletion of ozone. This study examined four hydrocarbon monoterpenes (d-limonene, {alpha}-pinene, {gamma}-terpinene, and terpinolene) and four alcohols (arbanol, linalool, plinol, and {alpha}-terpineol). Water solubility, vapor pressure, and octanol/water partition coefficients were estimated. Aerobic biodegradability tests were conducted in batch reactors by utilizing forest soil extract and enriched cultures as inoculum. The hydrophobic nature and high volatility of the hydrocarbons restricted the investigation to relatively low aqueous concentrations. Each monoterpene was analyzed with a gas chromatograph equipped with a flame ionization detector after extraction from the aqueous phase with isooctane. Terpene mineralization was tested by monitoring liquid-phase carbon, CO{sub 2} production and biomass growth. All four hydrocarbons and two alcohols readily degraded under aerobic conditions. Plinol resisted degradation in assays using inocula from diverse sources, while arbanol degraded very slowly. The intrinsic biokinetics coefficients for the degradation of d-limonene and {alpha}-terpineol were estimated by using cultures enriched with the respective monoterpenes. Monoterpene biodegradation followed Monod kinetics.

  12. Acute effects of aerobic exercise promote learning

    PubMed Central

    Perini, Renza; Bortoletto, Marta; Capogrosso, Michela; Fertonani, Anna; Miniussi, Carlo

    2016-01-01

    The benefits that physical exercise confers on cardiovascular health are well known, whereas the notion that physical exercise can also improve cognitive performance has only recently begun to be explored and has thus far yielded only controversial results. In the present study, we used a sample of young male subjects to test the effects that a single bout of aerobic exercise has on learning. Two tasks were run: the first was an orientation discrimination task involving the primary visual cortex, and the second was a simple thumb abduction motor task that relies on the primary motor cortex. Forty-four and forty volunteers participated in the first and second experiments, respectively. We found that a single bout of aerobic exercise can significantly facilitate learning mechanisms within visual and motor domains and that these positive effects can persist for at least 30 minutes following exercise. This finding suggests that physical activity, at least of moderate intensity, might promote brain plasticity. By combining physical activity–induced plasticity with specific cognitive training–induced plasticity, we favour a gradual up-regulation of a functional network due to a steady increase in synaptic strength, promoting associative Hebbian-like plasticity. PMID:27146330

  13. Impact of adding Saccharomyces strains on fermentation, aerobic stability, nutritive value, and select lactobacilli populations in corn silage.

    PubMed

    Duniere, L; Jin, L; Smiley, B; Qi, M; Rutherford, W; Wang, Y; McAllister, T

    2015-05-01

    Bacterial inoculants can improve the conservation and nutritional quality of silages. Inclusion of the yeast Saccharomyces in the diet of dairy cattle has also been reported to be beneficial. The present study assessed the ability of silage to be used as a means of delivering Saccharomyces strains to ruminants. Two strains of Saccharomyces cerevisiae (strain 1 and 3)and 1 strain of Saccharomyces paradoxus (strain 2) were inoculated (10(3) cfu/g) individually onto corn forage that was ensiled in mini silos for 90 d. Fermentation characteristics, aerobic stability, and nutritive value of silages were determined and real-time quantitative PCR (RT-qPCR) was used to quantify S. cerevisiae, S.paradoxus, total Saccharomyces, fungal, and bacterial populations. Fermentation characteristics of silage inoculated with S1 were similar to control silage. Although strain 3 inoculation increased ash and decreased OM contents of silage (P = 0.017), no differences were observed in nutrient composition or fermentation profiles after 90 d of ensiling. Inoculation with Saccharomyces had no detrimental effect on the aerobic stability of silage. In vitro DM disappearance, gas production, and microbial protein synthesis were not affected by yeast inoculation.Saccharomyces strain 1 was quantified throughout ensiling, whereas strain 2 was detected only immediately after inoculation. Saccharomyces cerevisiae strain 3 was quantified until d 7 and detectable 90 d after ensiling. All inoculants were detected and quantified during aerobic exposure. Inoculation with Saccharomyces did not alter lactobacilli populations. Saccharomycetales were detected by RT-qPCR throughout ensiling in all silages. Both S. cerevisiae and S. paradoxus populations increased during aerobic exposure, demonstrating that the density of these yeast strains would increase between the time that silage was removed from storage and the time it was fed. PMID:26020328

  14. Diversity and abundance of aerobic and anaerobic methane oxidizers at the Haakon Mosby Mud Volcano, Barents Sea.

    PubMed

    Lösekann, Tina; Knittel, Katrin; Nadalig, Thierry; Fuchs, Bernhard; Niemann, Helge; Boetius, Antje; Amann, Rudolf

    2007-05-01

    Submarine mud volcanoes are formed by expulsions of mud, fluids, and gases from deeply buried subsurface sources. They are highly reduced benthic habitats and often associated with intensive methane seepage. In this study, the microbial diversity and community structure in methane-rich sediments of the Haakon Mosby Mud Volcano (HMMV) were investigated by comparative sequence analysis of 16S rRNA genes and fluorescence in situ hybridization. In the active volcano center, which has a diameter of about 500 m, the main methane-consuming process was bacterial aerobic oxidation. In this zone, aerobic methanotrophs belonging to three bacterial clades closely affiliated with Methylobacter and Methylophaga species accounted for 56%+/-8% of total cells. In sediments below Beggiatoa mats encircling the center of the HMMV, methanotrophic archaea of the ANME-3 clade dominated the zone of anaerobic methane oxidation. ANME-3 archaea form cell aggregates mostly associated with sulfate-reducing bacteria of the Desulfobulbus (DBB) branch. These ANME-3/DBB aggregates were highly abundant and accounted for up to 94%+/-2% of total microbial biomass at 2 to 3 cm below the surface. ANME-3/DBB aggregates could be further enriched by flow cytometry to identify their phylogenetic relationships. At the outer rim of the mud volcano, the seafloor was colonized by tubeworms (Siboglinidae, formerly known as Pogonophora). Here, both aerobic and anaerobic methane oxidizers were found, however, in lower abundances. The level of microbial diversity at this site was higher than that at the central and Beggiatoa species-covered part of the HMMV. Analysis of methyl-coenzyme M-reductase alpha subunit (mcrA) genes showed a strong dominance of a novel lineage, mcrA group f, which could be assigned to ANME-3 archaea. Our results further support the hypothesis of Niemann et al. (54), that high methane availability and different fluid flow regimens at the HMMV provide distinct niches for aerobic and

  15. Aerobic salivary bacteria in wild and captive Komodo dragons.

    PubMed

    Montgomery, Joel M; Gillespie, Don; Sastrawan, Putra; Fredeking, Terry M; Stewart, George L

    2002-07-01

    During the months of November 1996, August 1997, and March 1998, saliva and plasma samples were collected for isolation of aerobic bacteria from 26 wild and 13 captive Komodo dragons (Varanus komodoensis). Twenty-eight Gram-negative and 29 Gram-positive species of bacteria were isolated from the saliva of the 39 Komodo dragons. A greater number of wild than captive dragons were positive for both Gram-negative and Gram-positive bacteria. The average number of bacterial species within the saliva of wild dragons was 46% greater than for captive dragons. While Escherichia coli was the most common bacterium isolated from the saliva of wild dragons, this species was not present in captive dragons. The most common bacteria isolated from the saliva of captive dragons were Staphylococcus capitis and Staphylococcus capitis and Staphylococcus caseolyticus, neither of which were found in wild dragons. High mortality was seen among mice injected with saliva from wild dragons and the only bacterium isolated from the blood of dying mice was Pasteurella multocida. A competitive inhibition enzyme-linked immunosorbent assay revealed the presence of anti-Pasteurella antibody in the plasma of Komodo dragons. Four species of bacteria isolated from dragon saliva showed resistance to one or more of 16 antimicrobics tested. The wide variety of bacteria demonstrated in the saliva of the Komodo dragon in this study, at least one species of which was highly lethal in mice and 54 species of which are known pathogens, support the observation that wounds inflicted by this animal are often associated with sepsis and subsequent bacteremia in prey animals. PMID:12238371

  16. Selective enrichment and characterization of a phosphorus-removing bacterial consortium from activated sludge.

    PubMed

    Hollender, J; Dreyer, U; Kornberger, L; Kämpfer, P; Dott, W

    2002-01-01

    Under alternating aerobic/anaerobic conditions and without additional carbon sources, a bacterial consortium consisting initially of 18 bacterial strains was obtained in a sequence batch reactor. The phosphorus removal capability could only be maintained using sterile filtrate of activated sludge as medium. The addition of calcium and magnesium salts, as well as vitamins and trace elements, to autoclaved sterile filtrate of activated sludge was not sufficient to achieve stable phosphorus removal. A further enrichment by subcultivation on solid, agar, freezing, and shortening of the aerobic and anaerobic phases led to a defined bacterial consortium consisting of four strains. On the basis of physiological and chemotaxonomic characterization, and partial 16S rRNA sequencing, one of the organisms was identified as Delftia acidovorans. A further isolate belonged to the Bacillus cereus group, and the third isolate was identified as Microbacterium sp.. The remaining strain seems to represent a new genus within the Flavobacteriaceae. Under continuous chemostat conditions, this consortium was able to remove up to 9.6 mg P/l phosphate in the aerobic phase and released up to 8.5 mg/l in the anaerobic phase. Up to 25 mg P-polyphosphate/g dry mass was stored under aerobic conditions. PMID:11831470

  17. DC KIDS COUNT e-Databook Indicators

    ERIC Educational Resources Information Center

    DC Action for Children, 2012

    2012-01-01

    This report presents indicators that are included in DC Action for Children's 2012 KIDS COUNT e-databook, their definitions and sources and the rationale for their selection. The indicators for DC KIDS COUNT represent a mix of traditional KIDS COUNT indicators of child well-being, such as the number of children living in poverty, and indicators of…

  18. Count-doubling time safety circuit

    DOEpatents

    Rusch, Gordon K.; Keefe, Donald J.; McDowell, William P.

    1981-01-01

    There is provided a nuclear reactor count-factor-increase time monitoring circuit which includes a pulse-type neutron detector, and means for counting the number of detected pulses during specific time periods. Counts are compared and the comparison is utilized to develop a reactor scram signal, if necessary.

  19. SPERM COUNT DISTRIBUTIONS IN FERTILE MEN

    EPA Science Inventory

    Sperm concentration and count are often used as indicators of environmental impacts on male reproductive health. Existing clinical databases may be biased towards subfertile men with low sperm counts and less is known about expected sperm count distributions in cohorts of fertil...

  20. 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. PMID:19573197

  1. 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…

  2. Psychological Benefits of Aerobic Running: Implications for Mental Health Counselors.

    ERIC Educational Resources Information Center

    Hinkle, J. Scott

    1988-01-01

    Discusses the effect of aerobic running on psychological functioning and its adjunctive use in mental health counseling. Concludes that mental health counselors can provide more comprehensive services if they expand the psychoeducational model to include physiological parameters such as aerobic running that are associated with optimum mental…

  3. The Psychology, Physiology, and Creativity of Middle School Aerobic Exercisers.

    ERIC Educational Resources Information Center

    Hinkle, J. Scott; And Others

    1993-01-01

    Investigated effects of aerobic running program on psychological and physical fitness and creative abilities of eight-grade school children. Students (n=85) were randomly assigned to aerobic running treatment groups or to control groups who participated in traditional, nonaerobic physical education. Found statistically significant increases for…

  4. 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…

  5. 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

  6. Aerobic Digestion. Student Manual. Biological Treatment Process Control.

    ERIC Educational Resources Information Center

    Klopping, Paul H.

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

  7. EFFECTS OF CORN SILAGE INOCULANTS ON AEROBIC STABILITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aerobic stability of corn silage can be a major problem for farmers particularly in warm weather. Silage inoculants, while the most common type of silage additive, have not been consistently effective at improving aerobic stability. This study investigated new and proposed inoculant products over ...

  8. 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)

  9. 40 CFR 796.3100 - Aerobic aquatic biodegradation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 32 2014-07-01 2014-07-01 false Aerobic aquatic biodegradation. 796.3100 Section 796.3100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Transformation Processes § 796.3100 Aerobic aquatic biodegradation. (a)...

  10. 40 CFR 796.3100 - Aerobic aquatic biodegradation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 33 2012-07-01 2012-07-01 false Aerobic aquatic biodegradation. 796.3100 Section 796.3100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Transformation Processes § 796.3100 Aerobic aquatic biodegradation. (a)...

  11. 40 CFR 796.3100 - Aerobic aquatic biodegradation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Aerobic aquatic biodegradation. 796.3100 Section 796.3100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Transformation Processes § 796.3100 Aerobic aquatic biodegradation. (a)...

  12. Kynetic resazurin assay (KRA) for bacterial quantification of foodborne pathogens

    NASA Astrophysics Data System (ADS)

    Arenas, Yaxal; Mandel, Arkady; Lilge, Lothar

    2012-03-01

    Fast detection of bacterial concentrations is important for the food industry and for healthcare. Early detection of infections and appropriate treatment is essential since, the delay of treatments for bacterial infections tends to be associated with higher mortality rates. In the food industry and in healthcare, standard procedures require the count of colony-forming units in order to quantify bacterial concentrations, however, this method is time consuming and reports require three days to be completed. An alternative is metabolic-colorimetric assays which provide time efficient in vitro bacterial concentrations. A colorimetric assay based on Resazurin was developed as a time kinetic assay (KRA) suitable for bacterial concentration measurements. An optimization was performed by finding excitation and emission wavelengths for fluorescent acquisition. A comparison of two non-related bacteria, foodborne pathogens Escherichia coli and Listeria monocytogenes, was performed in 96 well plates. A metabolic and clonogenic dependence was established for fluorescent kinetic signals.

  13. Bacterial Oxidation of Methyl Bromide in Fumigated Agricultural Soils

    PubMed Central

    Miller, L. G.; Connell, T. L.; Guidetti, J. R.; Oremland, R. S.

    1997-01-01

    The oxidation of [(sup14)C]methyl bromide ([(sup14)C]MeBr) to (sup14)CO(inf2) was measured in field experiments with soils collected from two strawberry plots fumigated with mixtures of MeBr and chloropicrin (CCl(inf3)NO(inf2)). Although these fumigants are considered potent biocides, we found that the highest rates of MeBr oxidation occurred 1 to 2 days after injection when the fields were tarped, rather than before or several days after injection. No oxidation of MeBr occurred in heat-killed soils, indicating that microbes were the causative agents of the oxidation. Degradation of MeBr by chemical and/or biological processes accounted for 20 to 50% of the loss of MeBr during fumigation, with evasion to the atmosphere inferred to comprise the remainder. In laboratory incubations, complete removal of [(sup14)C]MeBr occurred within a few days, with 47 to 67% of the added MeBr oxidized to (sup14)CO(inf2) and the remainder of counts associated with the solid phase. Chloropicrin inhibited the oxidation of MeBr, implying that use of this substance constrains the extent of microbial degradation of MeBr during fumigation. Oxidation was by direct bacterial attack of MeBr and not of methanol, a product of the chemical hydrolysis of MeBr. Neither nitrifying nor methane-oxidizing bacteria were sufficiently active in these soils to account for the observed oxidation of MeBr, nor could the microbial degradation of MeBr be linked to cooxidation with exogenously supplied electron donors. However, repeated addition of MeBr to live soils resulted in higher rates of its removal, suggesting that soil bacteria used MeBr as an electron donor for growth. To support this interpretation, we isolated a gram-negative, aerobic bacterium from these soils which grew with MeBr as a sole source of carbon and energy. PMID:16535728

  14. Bacterial oxidation of methyl bromide in fumigated agricultural soils.

    PubMed

    Miller, L G; Connell, T L; Guidetti, J R; Oremland, R S

    1997-11-01

    The oxidation of [(sup14)C]methyl bromide ([(sup14)C]MeBr) to (sup14)CO(inf2) was measured in field experiments with soils collected from two strawberry plots fumigated with mixtures of MeBr and chloropicrin (CCl(inf3)NO(inf2)). Although these fumigants are considered potent biocides, we found that the highest rates of MeBr oxidation occurred 1 to 2 days after injection when the fields were tarped, rather than before or several days after injection. No oxidation of MeBr occurred in heat-killed soils, indicating that microbes were the causative agents of the oxidation. Degradation of MeBr by chemical and/or biological processes accounted for 20 to 50% of the loss of MeBr during fumigation, with evasion to the atmosphere inferred to comprise the remainder. In laboratory incubations, complete removal of [(sup14)C]MeBr occurred within a few days, with 47 to 67% of the added MeBr oxidized to (sup14)CO(inf2) and the remainder of counts associated with the solid phase. Chloropicrin inhibited the oxidation of MeBr, implying that use of this substance constrains the extent of microbial degradation of MeBr during fumigation. Oxidation was by direct bacterial attack of MeBr and not of methanol, a product of the chemical hydrolysis of MeBr. Neither nitrifying nor methane-oxidizing bacteria were sufficiently active in these soils to account for the observed oxidation of MeBr, nor could the microbial degradation of MeBr be linked to cooxidation with exogenously supplied electron donors. However, repeated addition of MeBr to live soils resulted in higher rates of its removal, suggesting that soil bacteria used MeBr as an electron donor for growth. To support this interpretation, we isolated a gram-negative, aerobic bacterium from these soils which grew with MeBr as a sole source of carbon and energy. PMID:16535728

  15. Bacterial Cleanability of Various Types of Eating Surfaces.

    ERIC Educational Resources Information Center

    Ridenour, Gerald M.; Armbruster, E. H.

    1953-01-01

    Presents a study of the capability of commercial dishwashers to remove bacteria from various kinds of service plates. Gives an account of preliminary research on the bacterial cleanability of eating surfaces of different materials by two radiological procedures--(1) radiological count, and (2) autoradiographic measurement. Among the factors…

  16. Heart rate during aerobics classes in women with different previous experience of aerobics.

    PubMed

    Laukkanen, R M; Kalaja, M K; Kalaja, S P; Holmala, E B; Paavolainen, L M; Tummavuori, M; Virtanen, P; Rusko, H K

    2001-01-01

    This study measured heart rate during floor and step aerobic classes at three intensity levels. A group of 20 female occasional exercisers [mean age 33 (SD 8) years, mean body mass index 21 (SD 2) kg.m-2 volunteered to participate in six aerobic classes (three floor classes, three step classes) and in a laboratory test as members of one of two groups according to their prestudy regular participation in aerobics classes. Subjects in group A had participated four or more times a week and those of group B less than twice a week. The characteristics of the groups were as follows: group A, n = 10, mean maximal oxygen uptake (VO2max) 38.7 (SD 3.6) ml.kg-1.min-1, mean maximal heart rate (HRmax) 183 (SD 8) beats.min-1; group B, n = 10, VO2max 36.1 (SD 3.6) ml.kg-1.min-1, HRmax 178 (SD 7) beats.min-1. Each class consisted of a warm-up, a 20 min period of structured aerobic exercise (cardiophase) and a cool-down. The cardiophase was planned and guided as light, (rate of perceived exertion, RPE 11-12), moderate (RPE 13-14) or heavy (RPE 15-17) by an experienced instructor. The mean heart rates during the light classes were 72 (step) and 74 (floor) %HRmax in group A and 75 (step) and 79 (floor) %HRmax in group B; during the moderate classes, 84 (step) and 80 (floor) %HRmax in group A and 82 (step) and 83 (floor) %HRmax in group B, and during the heavy classes 89 (step and floor) %HRmax in group A and 88 (step) and 92 (floor) %HRmax in group B. Differences in heart rate and %HRmax were not statistically significant between the groups. However, differences in heart rate and %HRmax between the intensities (light vs moderate, moderate vs heavy and light vs heavy) were significant within both groups (all, P < 0.01). Based on the results, we conclude that intensity management during the aerobics classes was generally successful regardless of the participants' prior participation in aerobics. However, some individuals who were older and/or had less prior participation tended to

  17. Chromophore-enhanced bacterial photothermolysis

    NASA Astrophysics Data System (ADS)

    Huckleby, Jana K.; Morton, Rebecca J.; Bartels, Kenneth E.

    1999-06-01

    The use of chromophore dyes to enhance the bactericidal effect of laser energy was studied as a means to optimize laser treatment for the decontamination of wound. Using an in vitro study, various concentrations of indocyanine green (ICG), carbon black, and fluorescein were mixed with a suspension of bacteria and plated on tryptic soy agar. Plates were exposed to a laser beam of 10-15 watts for times ranging from 0 to 180 seconds, incubated overnight, and colony counts were performed. Bacteria not mixed with chromophore were used as controls. Six bacterial strains encompassing a range of bacterial types were used: Staphylococcus aureau, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus spore suspensions, and Clostridium perfringens. Laser treatment alone had no effect on any of the bacteria. Significant killing of gram-positive bacteria, including spores of Bacillus cereus, was observed only with the use of ICG and diode laser energy. No effect was observed using any of the chromophores on the gram-negative bacteria. The results of this study indicate that successful killing of gram-positive bacteria can be achieved using ICG combined with appropriate laser energy and wavelength. Efforts to enhance the susceptibility of gram-negative bacteria to photothermolysis by laser energy were unsuccessful.

  18. BACTERIAL DISSIMILATION OF STREPTOMYCIN1

    PubMed Central

    Klein, Dolph; Pramer, David

    1961-01-01

    Klein, Dolph (Rutgers, The State University, New Brunswick, N. J.), and David Pramer. Bacterial dissimilation of streptomycin. J. Bacteriol. 82:505–510. 1961.—The influence of various nutritional and environmental factors on the dissimilation of streptomycin by a pseudomonad isolated from soil was investigated, and conditions most suitable for growth of the bacterium, in a medium that contained streptomycin as a sole source of energy, nitrogen, and organic carbon, were determined. Development of the bacterium as measured by plate counts was correlated with degradation of streptomycin as measured by both biological and spectrophotometric assay procedures. Periodic analyses of culture filtrates indicated that the three constituent moieties of the streptomycin molecule underwent simultaneous transformation when the antibiotic was degraded microbiologically. Washed cell suspensions were capable of immediate and rapid oxidation of streptomycin, dihydrostreptomycin, and hydroxystreptomycin, but cell-free sonic extracts, in the absence and presence of cofactors, did not oxidize streptomycin or any of a number of derivatives or degradation products of the antibiotic. Evidence was obtained that the bacterial dissimilation of streptomycin involves an oxidation system in which methylene blue can act as hydrogen acceptor. PMID:14456730

  19. Normal somatic cell count and subclinical mastitis in Murrah buffaloes.

    PubMed

    Dhakal, I P

    2006-03-01

    This study was conducted to investigate the normal somatic cell count (SCC) and to define subclinical mastitis in Murrah buffaloes. Data were collected from 60 clinically normal buffaloes stationed at five farms of Chitwan Nepal and Buffalo Research Center, Hissar, India. Somatic cell count was measured using the Newman-Lampert staining technique. The upper limit of SCC was determined >or=200 000/ml of milk based on the mean +/- 2SD of a total SCC. Abnormal data of the SCC was repeatedly removed, which lie beyond the values of more than mean + 2SD until all the data come to lie within (mean + 2SD). Averages of SCC of right front and right hind quarters were significantly higher than left front and left hind quarters. Nearly 94% of California mastitis test (CMT) negative quarters were having somatic cells >or=200 000/ml. The mean SCC of CMT positive quarter was significantly higher (P < 0.01) than CMT negative quarters. Subclinical mastitis was diagnosed on the basis of samples with SCCs >or=200 000/ml with positive bacterial cultures. Subclinical mastitis was found in 21.7% buffaloes and 8% of the quarter foremilk samples. Neutrophil counts were significantly higher in subclinical mastitis milk. PMID:16626405

  20. Efficient quantification and characterization of bacterial outer membrane derived nano-particles with flow cytometric analysis.

    PubMed

    Wieser, Andreas; Storz, Enno; Liegl, Gabriele; Peter, Annabell; Pritsch, Michael; Shock, Jonathan; Wai, Sun Nyunt; Schubert, Sören

    2014-11-01

    There currently exists no efficient and easy method for size profiling and counting of membranous nano-scale particles, such as bacterial outer membrane vesicles (OMVs). We present here a cost-effective and fast method capable of profiling and counting small sample volumes of nano-scale membranous vesicles with standard laboratory equipment without the need for any washing steps. OMV populations of different bacterial species are compared and even subpopulations of OMVs can be identified after a simple labelling procedure. Counting is possible over three orders of magnitude without any changes to the protocol. Protein contaminations do not alter the described measurements. PMID:25139826

  1. Kids Count in Delaware, Families Count in Delaware: Fact Book, 2003.

    ERIC Educational Resources Information Center

    Delaware Univ., Newark. Kids Count in Delaware.

    This Kids Count Fact Book is combined with the Families Count Fact Book to provide information on statewide trends affecting children and families in Delaware. The Kids Count and Families Count indicators have been combined into four new categories: health and health behaviors, educational involvement and achievement, family environment and…

  2. [Quantitative urine microscopic examination using disposable counting chamber for diagnosis of urinary tract infection].

    PubMed

    Hida, Y; Yamashita, M; Gejyo, F; Hiraoka, M; Hori, C; Sudo, M

    1995-12-01

    Routine urinalysis is performed as a screening test for urinary tract infection (UTI) in out-patients or in-patients. We assessed the usefulness of microscopic examination of unspun and unstained urine using a disposable slide with counting chambers (Kova Slide 10 grid, Miles-Sankyo) for diagnosis of significant bacteriuria. 173 fresh urine samples were obtained from 173 subjects (89 male and 84 (female), including 117 inpatients, aged from 0 to 96 years. Urine samples were examined for bacteriuria by the standard culture method and counting chamber method. Significant bacteriuria was defined as 10(5)/ml or more of bacilli for midstream urine and urine collected by bags and 10(4)/ml or more for urine collected by catheterization and from indwelling catheters. Urine leukocytes were also counted on disposable slide. The rapid dipstick test (N-multistix-SG-10, Miles-Sankyo) of leukocyte esterase activity and nitrite were measured in the urine specimens read by a photometer (Clinitek-10, Miles-Sankyo). Significant bacteriuria was diagnosed by standard culture method in 67 urine samples. Close correlation was obtained between bacterial counts determined by the bacterial culture and counting chamber method (Spearman's correlation coefficient p < 0.001). Sensitivity and negative predictive value for significant bacteriuria were 94.0 and 95.1%, respectively, when bacteriuria or pyuria was present in the counting chamber. Dipstick test had a sensitivity and negative predictive value of 86.6 and 89.9%, respectively, when either leukocyte esterase activity of + or more, or nitrite of + was found. In out-patients, both sensitivity and negative predictive value were as high as 100% in counting chamber method. Thus, we can conclude that urine microscopy on disposable counting chambers is a very sensitive, simple, time-saving and lost-effective method for diagnosis of UTI. PMID:8569040

  3. Do bacterial cell numbers follow a theoretical Poisson distribution? Comparison of experimentally obtained numbers of single cells with random number generation via computer simulation.

    PubMed

    Koyama, Kento; Hokunan, Hidekazu; Hasegawa, Mayumi; Kawamura, Shuso; Koseki, Shigenobu

    2016-12-01

    We investigated a bacterial sample preparation procedure for single-cell studies. In the present study, we examined whether single bacterial cells obtained via 10-fold dilution followed a theoretical Poisson distribution. Four serotypes of Salmonella enterica, three serotypes of enterohaemorrhagic Escherichia coli and one serotype of Listeria monocytogenes were used as sample bacteria. An inoculum of each serotype was prepared via a 10-fold dilution series to obtain bacterial cell counts with mean values of one or two. To determine whether the experimentally obtained bacterial cell counts follow a theoretical Poisson distribution, a likelihood ratio test between the experimentally obtained cell counts and Poisson distribution which parameter estimated by maximum likelihood estimation (MLE) was conducted. The bacterial cell counts of each serotype sufficiently followed a Poisson distribution. Furthermore, to examine the validity of the parameters of Poisson distribution from experimentally obtained bacterial cell counts, we compared these with the parameters of a Poisson distribution that were estimated using random number generation via computer simulation. The Poisson distribution parameters experimentally obtained from bacterial cell counts were within the range of the parameters estimated using a computer simulation. These results demonstrate that the bacterial cell counts of each serotype obtained via 10-fold dilution followed a Poisson distribution. The fact that the frequency of bacterial cell counts follows a Poisson distribution at low number would be applied to some single-cell studies with a few bacterial cells. In particular, the procedure presented in this study enables us to develop an inactivation model at the single-cell level that can estimate the variability of survival bacterial numbers during the bacterial death process. PMID:27554145

  4. Somatic Cell Counts in Bovine Milk

    PubMed Central

    Dohoo, I. R.; Meek, A. H.

    1982-01-01

    Factors which influence somatic cell counts in bovine milk are reviewed and guidelines for their interpretation are presented. It is suggested that the thresholds of 300 000 and 250 000 cells/mL be used to identify infected quarters and cows respectively. However, it is stressed that somatic cell counts are general indicators of udder health which are subject to the influence of many factors. Therefore the evaluation of several successive counts is preferable to the interpretation of an individual count. Relationships between somatic cell counts and both milk production and milk composition are discussed. Subclinical mastitis reduces milk quality and decreases yield although the relationship between production loss and somatic cell count requires clarification. Finally the availability of somatic cell counting programs in Canada is presented. PMID:17422127

  5. Live/Dead Bacterial Spore Assay Using DPA-Triggered Tb Luminescence

    NASA Technical Reports Server (NTRS)

    Ponce, Adrian

    2003-01-01

    A method of measuring the fraction of bacterial spores in a sample that remain viable exploits DPA-triggered luminescence of Tb(3+) and is based partly on the same principles as those described earlier. Unlike prior methods for performing such live/dead assays of bacterial spores, this method does not involve counting colonies formed by cultivation (which can take days), or counting of spores under a microscope, and works whether or not bacterial spores are attached to other small particles (i.e., dust), and can be implemented on a time scale of about 20 minutes.

  6. Comparison of plate counts, Petrifilm, dipslides, and adenosine triphosphate bioluminescence for monitoring bacteria in cooling-tower waters.

    PubMed

    Mueller, Sherry A; Anderson, James E; Kim, Byung R; Ball, James C

    2009-04-01

    Effective bacterial control in cooling-tower systems requires accurate and timely methods to count bacteria. Plate-count methods are difficult to implement on-site, because they are time- and labor-intensive and require sterile techniques. Several field-applicable methods (dipslides, Petrifilm, and adenosine triphosphate [ATP] bioluminescence) were compared with the plate count for two sample matrices--phosphate-buffered saline solution containing a pure culture of Pseudomonas fluorescens and cooling-tower water containing an undefined mixed bacterial culture. For the pure culture, (1) counts determined on nutrient agar and plate-count agar (PCA) media and expressed as colony-forming units (CFU) per milliliter were equivalent to those on R2A medium (p = 1.0 and p = 1.0, respectively); (2) Petrifilm counts were not significantly different from R2A plate counts (p = 0.99); (3) the dipslide counts were up to 2 log units higher than R2A plate counts, but this discrepancy was not statistically significant (p = 0.06); and (4) a discernable correlation (r2 = 0.67) existed between ATP readings and plate counts. For cooling-tower water samples (n = 62), (1) bacterial counts using R2A medium were higher (but not significant; p = 0.63) than nutrient agar and significantly higher than tryptone-glucose yeast extract (TGE; p = 0.03) and PCA (p < 0.001); (2) Petrifilm counts were significantly lower than nutrient agar or R2A (p = 0.02 and p < 0.001, respectively), but not statistically different from TGE, PCA, and dipslides (p = 0.55, p = 0.69, and p = 0.91, respectively); (3) the dipslide method yielded bacteria counts 1 to 3 log units lower than nutrient agar and R2A (p < 0.001), but was not significantly different from Petrifilm (p = 0.91), PCA (p = 1.00) or TGE (p = 0.07); (4) the differences between dipslides and the other methods became greater with a 6-day incubation time; and (5) the correlation between ATP readings and plate counts varied from system to system, was poor

  7. Preparation and evaluation of bacterial stocks for filter validation.

    PubMed

    Fennington, G J; Howard, G

    1997-01-01

    Bacterial cell stock paste of Brevundimonas diminuta (American Type Culture Collection # 19146) used for filter validation was evaluated by standard microbiological procedures to determine culture purity, monodispersion, cell size, and strain identity. Tests performed included direct microscopic count, standard plate count, gram stain, streak plate, sizing by microfiltration, scanning electron microscopy, and biochemical identification. Results indicated the bacterial stocks were of consistent quality in terms of bacteriological purity, cell size, viability, and concentration. Sizing by microfiltration confirmed consistent monodispersion and cell retention characteristics for each lot tested. Use of the commercially available RapID NF Plus system confirmed each lot to be B. diminuta as indicated by biochemical profile and identification database. These tests represent parameters necessary for qualification of bacterial stocks to be used for filter validation. PMID:9277123

  8. Brain aerobic glycolysis and motor adaptation learning

    PubMed Central

    Shannon, Benjamin J.; Vaishnavi, Sanjeev Neil; Vlassenko, Andrei G.; Shimony, Joshua S.; Rutlin, Jerrel; Raichle, Marcus E.

    2016-01-01

    Ten percent to 15% of glucose used by the brain is metabolized nonoxidatively despite adequate tissue oxygenation, a process termed aerobic glycolysis (AG). Because of the known role of glycolysis in biosynthesis, we tested whether learning-induced synaptic plasticity would lead to regionally appropriate, learning-dependent changes in AG. Functional MRI (fMRI) before, during, and after performance of a visual–motor adaptation task demonstrated that left Brodmann area 44 (BA44) played a key role in adaptation, with learning-related changes to activity during the task and altered resting-state, functional connectivity after the task. PET scans before and after task performance indicated a sustained increase in AG in left BA 44 accompanied by decreased oxygen consumption. Intersubject variability in behavioral adaptation rate correlated strongly with changes in AG in this region, as well as functional connectivity, which is consistent with a role for AG in synaptic plasticity. PMID:27217563

  9. Surface Structure of Aerobically Oxidized Diamond Nanocrystals

    PubMed Central

    2015-01-01

    We investigate the aerobic oxidation of high-pressure, high-temperature nanodiamonds (5–50 nm dimensions) using a combination of carbon and oxygen K-edge X-ray absorption, wavelength-dependent X-ray photoelectron, and vibrational spectroscopies. Oxidation at 575 °C for 2 h eliminates graphitic carbon contamination (>98%) and produces nanocrystals with hydroxyl functionalized surfaces as well as a minor component (<5%) of carboxylic anhydrides. The low graphitic carbon content and the high crystallinity of HPHT are evident from Raman spectra acquired using visible wavelength excitation (λexcit = 633 nm) as well as carbon K-edge X-ray absorption spectra where the signature of a core–hole exciton is observed. Both spectroscopic features are similar to those of chemical vapor deposited (CVD) diamond but differ significantly from the spectra of detonation nanodiamond. The importance of these findings to the functionalization of nanodiamond surfaces for biological labeling applications is discussed. PMID:25436035

  10. Aerobic Microbial Degradation of Glucoisosaccharinic Acid

    PubMed Central

    Strand, S. E.; Dykes, J.; Chiang, V.

    1984-01-01

    α-Glucoisosaccharinic acid (GISA), a major by-product of kraft paper manufacture, was synthesized from lactose and used as the carbon source for microbial media. Ten strains of aerobic bacteria capable of growth on GISA were isolated from kraft pulp mill environments. The highest growth yields were obtained with Ancylobacter spp. at pH 7.2 to 9.5. GISA was completely degraded by cultures of an Ancylobacter isolate. Ancylobacter cell suspensions consumed oxygen and produced carbon dioxide in response to GISA addition. A total of 22 laboratory strains of bacteria were tested, and none was capable of growth on GISA. GISA-degrading isolates were not found in forest soils. Images PMID:16346467

  11. Brain aerobic glycolysis and motor adaptation learning.

    PubMed

    Shannon, Benjamin J; Vaishnavi, Sanjeev Neil; Vlassenko, Andrei G; Shimony, Joshua S; Rutlin, Jerrel; Raichle, Marcus E

    2016-06-28

    Ten percent to 15% of glucose used by the brain is metabolized nonoxidatively despite adequate tissue oxygenation, a process termed aerobic glycolysis (AG). Because of the known role of glycolysis in biosynthesis, we tested whether learning-induced synaptic plasticity would lead to regionally appropriate, learning-dependent changes in AG. Functional MRI (fMRI) before, during, and after performance of a visual-motor adaptation task demonstrated that left Brodmann area 44 (BA44) played a key role in adaptation, with learning-related changes to activity during the task and altered resting-state, functional connectivity after the task. PET scans before and after task performance indicated a sustained increase in AG in left BA 44 accompanied by decreased oxygen consumption. Intersubject variability in behavioral adaptation rate correlated strongly with changes in AG in this region, as well as functional connectivity, which is consistent with a role for AG in synaptic plasticity. PMID:27217563

  12. New Routes for Aerobic Biodegradation of Dimethylsulfoniopropionate

    PubMed Central

    Taylor, Barrie F.; Gilchrist, Darrin C.

    1991-01-01

    Dimethylsulfoniopropionate (DMSP), an osmolyte in marine plants, is biodegraded by cleavage of dimethyl sulfide (DMS) or by demethylation to 3-methiolpropionate (MMPA) and 3-mercaptopropionate (MPA). Sequential demethylation has been observed only with anoxic slurries of coastal sediments. Bacteria that grew aerobically on MMPA and DMSP were isolated from marine environments and phytoplankton cultures. Enrichments with DMSP selected for bacteria that generated DMS, whereas MMPA enrichments selected organisms that produced methanethiol (CH3SH) from either DMSP or MMPA. A bacterium isolated on MMPA grew on MMPA and DMSP, but rapid production of CH3SH from DMSP occurred only with DMSP-grown cells. Low levels of MPA accumulated during growth on MMPA, indicating demethylation as well as demethiolation of MMPA. The alternative routes for DMSP biodegradation via MMPA probably impact on net DMS fluxes to the marine atmosphere. PMID:16348607

  13. [Research of aerobic granule characteristics with different granule age].

    PubMed

    Zhou, Man; Yang, Chang-Zhu; Pu, Wen-Hong; Luo, Ying-Dong; Gong, Jian-Yu

    2012-03-01

    In the SBR reactor, we studied the different style, physicochemical characteristic, pollutants removal and microbial activity between the short age and long age aerobic granule, respectively. The short age aerobic granule was cultivated from activated floccules sludge and the other was gotten from aerobic granular sludge which was operated stably more than one year. The results indicated that the wet density, the specific gravity and integrated coefficient (IC) of the short age aerobic granule were 1.066 g x cm(-1), 1.013 g x cm(-3) and 98.7%, respectively. And that of long age were 1.026 g x cm(-3), 1.010 g x cm(-3) and 98.4%, respectively. All of them were higher than the long age aerobic granule. The mean diameters of them were 1.9 mm and 2.2 mm, respectively. The settling velocity of short age and long age aerobic granule were 0.005-0.032 m x s(-1) and 0.003-0.028 m x s(-1), respectively, and two kinds of aerobic granule settling velocity increased with the diameter increased. SVI of the former was lower. The COD removal rates of two aerobic granules were above 90%, and the NH4(+) -N removal rates of them were about 85%. The results of the COD effluent concentration, NH4(+) -N effluent concentration and the pollutants concentration in a typical cycle indicated that the short age aerobic granule had better pollutants removal efficiency. The TP removal rates of them were between 40% -90% and 32% -85%, respectively. The TN removal rates of them were about 80%. The SOUR(H) SOUR(NH4) and SOUR(NO2) of the short age aerobic granule were 26.4, 14.8 and 11.2 mg x (h x g)(-1), respectively. And that of long age were 25.2, 14.4 and 8.4 mg x (h x g)(-1), respectively. In summary, the aerobic granule had significantly different physical and chemical characteristics because of different granule age, and the short age aerobic granule exhibited better pollutants removal ability, higher microbial activity and more stability than the long age aerobic granule. PMID:22624385

  14. Effects of Kettlebell Training on Aerobic Capacity.

    PubMed

    Falatic, J Asher; Plato, Peggy A; Holder, Christopher; Finch, Daryl; Han, Kyungmo; Cisar, Craig J

    2015-07-01

    This study examined the effects of a kettlebell training program on aerobic capacity. Seventeen female National Collegiate Athletic Association Division I collegiate soccer players (age: 19.7 ± 1.0 years, height: 166.1 ± 6.4 cm, weight: 64.2 ± 8.2 kg) completed a graded exercise test to determine maximal oxygen consumption (V̇O2max). Participants were assigned to a kettlebell intervention group (KB) (n = 9) or a circuit weight-training (CWT) control group (n = 8). Participants in the KB group completed a kettlebell snatch test to determine individual snatch repetitions. Both groups trained 3 days a week for 4 weeks in addition to their off-season strength and conditioning program. The KB group performed the 15:15 MVO2 protocol (20 minutes of kettlebell snatching with 15 seconds of work and rest intervals). The CWT group performed multiple free-weight and dynamic body-weight exercises as part of a continuous circuit program for 20 minutes. The 15:15 MVO2 protocol significantly increased V̇O2max in the KB group. The average increase was 2.3 ml·kg⁻¹·min⁻¹, or approximately a 6% gain. There was no significant change in V̇O2max in the CWT control group. Thus, the 4-week 15:15 MVO2 kettlebell protocol, using high-intensity kettlebell snatches, significantly improved aerobic capacity in female intercollegiate soccer players and could be used as an alternative mode to maintain or improve cardiovascular conditioning. PMID:26102260

  15. Single-cell activity of freshwater aerobic anoxygenic phototrophic bacteria and their contribution to biomass production.

    PubMed

    Garcia-Chaves, Maria C; Cottrell, Matthew T; Kirchman, David L; Ruiz-González, Clara; Del Giorgio, Paul A

    2016-07-01

    Aerobic anoxygenic phototrophic (AAP) bacteria are photoheterotrophs that despite their low abundances have been hypothesized to play an ecologically and biogeochemically important role in aquatic systems. Characterizing this role requires a better understanding of the in situ dynamics and activity of AAP bacteria. Here we provide the first assessment of the single-cell activity of freshwater AAP bacteria and their contribution to total bacterial production across lakes spanning a wide trophic gradient, and explore the role of light in regulating AAP activity. The proportion of cells that were active in leucine incorporation and the level of activity per cell were consistently higher for AAP than for bulk bacteria across lakes. As a result, AAP bacteria contributed disproportionately more to total bacterial production than to total bacterial abundance. Interestingly, although environmentally driven patterns in activity did not seem to differ largely between AAP and bulk bacteria, their response to light did, and exposure to light resulted in increases in the proportion of active AAP bacteria with no clear effect on their cell-specific activity. This suggests that light may play a role in the activation of AAP bacteria, enabling these photoheterotrophs to contribute more to the carbon cycle than suggested by their abundance. PMID:26771928

  16. Bacterial hydroxylation of codeine

    SciTech Connect

    Harder, P.A.; Kunz, D.A.

    1989-01-17

    A process is described for preparing 14-hydroxycodeine which comprises: contacting codeine or a water-soluble salt thereof with bacteria of the genus Streptomyces for a period of at least about three days while the bacteria are being aerobically cultured in a rich medium in which the growth nutrients are supplied in excess and recovering 14-hydroxycodeine from the medium.

  17. New method for estimating bacterial cell abundances in natural samples by use of sublimation

    NASA Technical Reports Server (NTRS)

    Glavin, Daniel P.; Cleaves, H. James; Schubert, Michael; Aubrey, Andrew; Bada, Jeffrey L.

    2004-01-01

    We have developed a new method based on the sublimation of adenine from Escherichia coli to estimate bacterial cell counts in natural samples. To demonstrate this technique, several types of natural samples, including beach sand, seawater, deep-sea sediment, and two soil samples from the Atacama Desert, were heated to a temperature of 500 degrees C for several seconds under reduced pressure. The sublimate was collected on a cold finger, and the amount of adenine released from the samples was then determined by high-performance liquid chromatography with UV absorbance detection. Based on the total amount of adenine recovered from DNA and RNA in these samples, we estimated bacterial cell counts ranging from approximately 10(5) to 10(9) E. coli cell equivalents per gram. For most of these samples, the sublimation-based cell counts were in agreement with total bacterial counts obtained by traditional DAPI (4,6-diamidino-2-phenylindole) staining.

  18. Photon counting compressive depth mapping.

    PubMed

    Howland, Gregory A; Lum, Daniel J; Ware, Matthew R; Howell, John C

    2013-10-01

    We demonstrate a compressed sensing, photon counting lidar system based on the single-pixel camera. Our technique recovers both depth and intensity maps from a single under-sampled set of incoherent, linear projections of a scene of interest at ultra-low light levels around 0.5 picowatts. Only two-dimensional reconstructions are required to image a three-dimensional scene. We demonstrate intensity imaging and depth mapping at 256 × 256 pixel transverse resolution with acquisition times as short as 3 seconds. We also show novelty filtering, reconstructing only the difference between two instances of a scene. Finally, we acquire 32 × 32 pixel real-time video for three-dimensional object tracking at 14 frames-per-second. PMID:24104293

  19. Low Background Counting At SNOLAB

    SciTech Connect

    Lawson, Ian; Cleveland, Bruce

    2011-04-27

    It is a continuous and ongoing effort to maintain radioactivity in materials and in the environment surrounding most underground experiments at very low levels. These low levels are required so that experiments can achieve the required detection sensitivities for the detection of low-energy neutrinos, searches for dark matter and neutrinoless double-beta decay. SNOLAB has several facilities which are used to determine these low background levels in the materials and the underground environment. This proceedings will describe the SNOLAB High Purity Germanium Detector which has been in continuous use for the past five years and give results of many of the items that have been counted over that period. Brief descriptions of SNOLAB's alpha-beta and electrostatic counters will be given, and the radon levels at SNOLAB will be discussed.

  20. Counting solutions from finite samplings.

    PubMed

    Huang, Haiping; Zhou, Haijun

    2012-02-01

    We formulate the solution counting problem within the framework of the inverse Ising problem and use fast belief propagation equations to estimate the entropy whose value provides an estimate of the true one. We test this idea on both diluted models [random 2-SAT (2-satisfiability) and 3-SAT problems] and a fully connected model (binary perceptron), and show that when the constraint density is small, this estimate can be very close to the true value. The information stored by the salamander retina under the natural movie stimuli can also be estimated, and our result is consistent with that obtained by the Monte Carlo method. Of particular significance is that the sizes of other metastable states for this real neuronal network are predicted. PMID:22463290

  1. Counting solutions from finite samplings

    NASA Astrophysics Data System (ADS)

    Huang, Haiping; Zhou, Haijun

    2012-02-01

    We formulate the solution counting problem within the framework of the inverse Ising problem and use fast belief propagation equations to estimate the entropy whose value provides an estimate of the true one. We test this idea on both diluted models [random 2-SAT (2-satisfiability) and 3-SAT problems] and a fully connected model (binary perceptron), and show that when the constraint density is small, this estimate can be very close to the true value. The information stored by the salamander retina under the natural movie stimuli can also be estimated, and our result is consistent with that obtained by the Monte Carlo method. Of particular significance is that the sizes of other metastable states for this real neuronal network are predicted.

  2. 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.

  3. Presence of aerobic micro-organisms and their influence on basic semen parameters in infertile men.

    PubMed

    Filipiak, E; Marchlewska, K; Oszukowska, E; Walczak-Jedrzejowska, R; Swierczynska-Cieplucha, A; Kula, K; Slowikowska-Hilczer, J

    2015-09-01

    Urogenital tract infections in males are one of the significant etiological factors in infertility. In this prospective study, 72 patients with abnormal semen parameters or any other symptoms of urogenital tract infection were examined. Semen analysis according to the WHO 2010 manual was performed together with microbial assessment: aerobic bacteria culture, Chlamydia antigen test, Candida culture, Ureaplasma and Mycoplasma-specific culture. In total, 69.4% of semen samples were positive for at least one micro-organism. Ureaplasma sp. was the most common micro-organism found in 33% of semen samples of infertile patients with suspected male genital tract infection. The 2nd most common micro-organisms were Enterococcus faecalis (12.5%) and Escherichia coli (12.5%), followed by Staphylococcus aureus (7%), Chlamydia trachomatis (7%) and Candida sp. (5.6%). Generally, bacteria were sensitive to at least one of the antibiotics tested. No statistically significant relationship was observed between the presence of aerobic micro-organisms in semen and basic semen parameters: volume, pH, concentration, total count, motility, vitality and morphology. PMID:25209133

  4. Aerobic and anaerobic metabolism of 6,10,14-trimethylpentadecan-2-one by a denitrifying bacterium isolated from marine sediments.

    PubMed Central

    Rontani, J F; Gilewicz, M J; Michotey, V D; Zheng, T L; Bonin, P C; Bertrand, J C

    1997-01-01

    This report describes the metabolism of 6,10,14-trimethylpentadecan-2-one by a denitrifying bacterium (Marinobacter sp. strain CAB) isolated from marine sediments. Under aerobic and denitrifying conditions, this strain efficiently degraded this ubiquitous isoprenoid ketone. Several bacterial metabolites, 4,8,12-trimethyl-tridecan-1-ol, 4,8,12-trimethyltridecanal, 4,8,12-trimethyltridecanoic acid, Z-3,7-dimethylocten-2-oic acid, Z-3,7,11-trimethyldodecen-2-oic acid, and 6,10,14-trimethylpentadecan-2-ol, were formally identified, and different pathways were proposed to explain the formation of such isoprenoid compounds. PMID:9023941

  5. Influence of power and aerobic exercise training on haemostatic factors after coronary artery surgery

    PubMed Central

    Wosornu, D; Allardyce, W; Ballantyne, D; Tansey, P

    1992-01-01

    Objectives—To determine the effects of aerobic and power exercise training on haemostatic factors after coronary artery surgery and to compare the effect of the two exercise programmes. Design—A prospective randomised controlled study of six months aerobic and power exercise training in men after coronary artery surgery. Setting—Exercise rehabilitation classes in a teaching hospital in Glasgow. Patients—55 men within 12 months of coronary artery surgery recruited from surgical centres and medical clinics and asked to participate in the study. Interventions—Assessments, including a treadmill test, measurements of haemoglobin, platelet, fibrinogen, factor VIIc, and fibrinopeptide A concentrations, and packed cell volume, done at baseline, three months, and six months. Patients in the two exercise groups attended training sessions three times weekly for six months. Control patients had no formal exercise training but continued with their leisure time activities. Main outcome measures—Exercise performance on a treadmill, haematology, and haemostatic factor assays at baseline, three months, and six months. Results—In the aerobic trained group exercise performance increased significantly over baseline at three months (interval change 146·7, 95% confidence interval (95% CI) 52·5 to 240·9 s, p = 0·003) and was maintained at six months (interval change 172·1, 95% CI 63·3 to 280·9 s, p = 0·002). In the power trained groups significant improvement in exercise performance was delayed until six months (interval change 99·9 s, 95% CI 20·3 to 170·5 s, p = 0·01). Exercise performance in the control did not change significantly. Haemoglobin, concentration, packed cell volume, and platelet counts did not change significantly at any time. Fibrinogen concentration was significantly lower in the aerobic group than the other two groups at three months (2·96 g/dl compared with 3·3 g/dl and 3·87 g/dl in the power and control groups, p = 0·01). The power group

  6. Diverse Arrangement of Photosynthetic Gene Clusters in Aerobic Anoxygenic Phototrophic Bacteria

    PubMed Central

    Zheng, Qiang; Zhang, Rui; Koblížek, Michal; Boldareva, Ekaterina N.; Yurkov, Vladimir; Yan, Shi; Jiao, Nianzhi

    2011-01-01

    Background Aerobic anoxygenic photototrophic (AAP) bacteria represent an important group of marine microorganisms inhabiting the euphotic zone of the ocean. They harvest light using bacteriochlorophyll (BChl) a and are thought to be important players in carbon cycling in the ocean. Methodology/Principal Findings Aerobic anoxygenic phototrophic (AAP) bacteria represent an important part of marine microbial communities. Their photosynthetic apparatus is encoded by a number of genes organized in a so-called photosynthetic gene cluster (PGC). In this study, the organization of PGCs was analyzed in ten AAP species belonging to the orders Rhodobacterales, Sphingomonadales and the NOR5/OM60 clade. Sphingomonadales contained comparatively smaller PGCs with an approximately size of 39 kb whereas the average size of PGCs in Rhodobacterales and NOR5/OM60 clade was about 45 kb. The distribution of four arrangements, based on the permutation and combination of the two conserved regions bchFNBHLM-LhaA-puhABC and crtF-bchCXYZ, does not correspond to the phylogenetic affiliation of individual AAP bacterial species. While PGCs of all analyzed species contained the same set of genes for bacteriochlorophyll synthesis and assembly of photosynthetic centers, they differed largely in the carotenoid biosynthetic genes. Spheroidenone, spirilloxanthin, and zeaxanthin biosynthetic pathways were found in each clade respectively. All of the carotenoid biosynthetic genes were found in the PGCs of Rhodobacterales, however Sphingomonadales and NOR5/OM60 strains contained some of the carotenoid biosynthetic pathway genes outside of the PGC. Conclusions/Significance Our investigations shed light on the evolution and functional implications in PGCs of marine aerobic anoxygenic phototrophs, and support the notion that AAP are a heterogenous physiological group phylogenetically scattered among Proteobacteria. PMID:21949847

  7. Aerobic carboxydotrophy under extremely haloalkaline conditions in Alkalispirillum/Alkalilimnicola strains isolated from soda lakes.

    PubMed

    Sorokin, Dimitry Yu; Tourova, Tatjana P; Kovaleva, Olga L; Kuenen, J Gijs; Muyzer, Gerard

    2010-03-01

    Aerobic enrichments from soda lake sediments with CO as the only substrate resulted in the isolation of five bacterial strains capable of autotrophic growth with CO at extremely high pH and salinity. The strains belonged to the Alkalispirillum/Alkalilimnicola cluster in the Gammaproteobacteria, where the ability to oxidize CO, but not growth with CO, has been demonstrated previously. The growth with CO was possible only at an oxygen concentration below 5 % and CO concentration below 20 % in the gas phase. The isolates were also capable of growth with formate but not with H(2). The carboxydotrophic growth occurred within a narrow pH range from 8 to 10.5 (optimum at 9.5) and a broad salt concentration from 0.3 to 3.5 M total Na(+) (optimum at 1.0 M). Cells grown on CO had high respiration activity with CO and formate, while the cells grown on formate actively oxidized formate alone. In CO-grown cells, CO-dehydrogenase (CODH) activity was detectable both in soluble and membrane fractions, while the NAD-independent formate dehydrogenase (FDH) resided solely in membranes. The results of total protein profiling and the failure to detect CODH with conventional primers for the coxL gene indicated that the CO-oxidizing enzyme in haloalkaliphilic isolates might differ from the classical aerobic CODH complex. A single cbbL gene encoding the RuBisCO large subunit was detected in all strains, suggesting the presence of the Calvin cycle of inorganic carbon fixation. Overall, these results demonstrated the possibility of aerobic carboxydotrophy under extremely haloalkaline conditions. PMID:19959573

  8. Sequential anaerobic/aerobic biotreatment of bark leachate.

    PubMed

    Frigon, J C; Cimpoia, R; Guiot, S R

    2003-01-01

    Bark leachate is generated from sawmill operations such as log storage sites and contains polymeric tannins, carbohydrates, organic acids, phenolic and resin compounds. The present study was aimed at assessing the performance of a sequential anaerobic and aerobic treatment, for both chemical oxygen demand (COD) and phenol removal, under various combinations of operational conditions, in the continuous mode. After anaerobic treatment in a five litres upflow anaerobic sludge bed (UASB) reactor, the leachate was directed into two parallel aerobic reactors, either an activated sludge unit or a fixed film submerged filter (packed with polyethylene Flexirings), both of a volume of one litre and oxygenated by air diffusion. For a leachate of 22 gCOD/l, an overall COD removal of 96-98% was achieved at an hydraulic residence time (HRT) of 4 days for the anaerobic reactor and one day for either aerobic systems. The phenol concentration generally increased after anaerobic treatment but was below the detection limit (50 ppb) after aerobic polishing. Radiorespirometric microcosms with 14C-labelled phenol confirmed that phenol was mineralized in the aerobic reactors. The performances of both aerobic systems were similar for COD and phenol removal. Thus, a sequential anaerobic/aerobic treatment was able to effectively address the contamination of a bark leachate discharge, including phenols. PMID:14640219

  9. Cardioprotective Properties of Aerobic and Resistance Training Against Myocardial Infarction.

    PubMed

    Barboza, C A; Souza, G I H; Oliveira, J C M F; Silva, L M; Mostarda, C T; Dourado, P M M; Oyama, L M; Lira, F S; Irigoyen, M C; Rodrigues, B

    2016-06-01

    We evaluated the effects of aerobic and resistance exercise training on ventricular morphometry and function, physical capacity, autonomic function, as well as on ventricular inflammatory status in trained rats prior to myocardial infarction. Male Wistar rats were divided into the following groups: sedentary+Sham, sedentary+myocardial infarction, aerobic trained+myocardial infarction, and resistance trained+myocardial infarction. Sham and myocardial infarction were performed after training periods. In the days following the surgeries, evaluations were performed. Aerobic training prevents aerobic (to a greater extent) and resistance capacity impairments, ventricular dysfunction, baroreflex sensitivity and autonomic disorders (vagal tonus decrease and sympathetic tonus increase) triggered by myocardial infarction. Resistance training was able to prevent negative changes to aerobic and resistance capacity (to a greater extent) but not to ventricular dysfunction, and it prevented cardiovascular sympathetic increments. Additionally, both types of training reduced left ventricle inflammatory cytokine concentration. Our results suggest that aerobic and, for the first time, dynamic resistance training were able to reduce sympathetic tonus to the heart and vessels, as well as preventing the increase in pro-inflammatory cytokine concentrations in the left ventricle of trained groups. These data emphasizes the positive effects of aerobic and dynamic resistance training on the prevention of the negative changes triggered by myocardial infarction. PMID:26928914

  10. Comparative Analysis of Lacinutrix Genomes and Their Association with Bacterial Habitat

    PubMed Central

    Lee, Yung Mi; Kim, Mi-Kyeong; Ahn, Do Hwan; Kim, Han-Woo; Park, Hyun; Shin, Seung Chul

    2016-01-01

    The genus Lacinutrix, which belongs to the family Flavobacteriaceae, consists of seven bacterial species that were mainly isolated from marine life and sediments. As most bacteria in the family Flavobacteriaceae favor aerobic conditions, the seven bacterial species in the genus Lacinutrix also showed aerobic growth. We selected four monophyletic bacterial species living in a polar environment. Two of these species were isolated from sediment and two types were isolated from algae. In a comparative analysis, we investigated how these different environments were related to genomic features of these four species in the genus Lacinutrix. We found that the gene sets for glycolysis, the Krebs cycle, and oxidative phosphorylation were conserved in these four type strains. However, the presence of nitrous oxide reductase for denitrification and the absence of essential components related to thiamin biosynthesis for aerobic respiration were only found in isolates from sediment. Elevated bacterial metabolism on the surface of marine sediments might limit the oxygen penetration into sediment, and such an environment might affect the genomes of bacteria isolated from these habitats. PMID:26882010

  11. Comparative Analysis of Lacinutrix Genomes and Their Association with Bacterial Habitat.

    PubMed

    Lee, Yung Mi; Kim, Mi-Kyeong; Ahn, Do Hwan; Kim, Han-Woo; Park, Hyun; Shin, Seung Chul

    2016-01-01

    The genus Lacinutrix, which belongs to the family Flavobacteriaceae, consists of seven bacterial species that were mainly isolated from marine life and sediments. As most bacteria in the family Flavobacteriaceae favor aerobic conditions, the seven bacterial species in the genus Lacinutrix also showed aerobic growth. We selected four monophyletic bacterial species living in a polar environment. Two of these species were isolated from sediment and two types were isolated from algae. In a comparative analysis, we investigated how these different environments were related to genomic features of these four species in the genus Lacinutrix. We found that the gene sets for glycolysis, the Krebs cycle, and oxidative phosphorylation were conserved in these four type strains. However, the presence of nitrous oxide reductase for denitrification and the absence of essential components related to thiamin biosynthesis for aerobic respiration were only found in isolates from sediment. Elevated bacterial metabolism on the surface of marine sediments might limit the oxygen penetration into sediment, and such an environment might affect the genomes of bacteria isolated from these habitats. PMID:26882010

  12. Upper limb aerobic training improves aerobic fitness and all-out performance of America's Cup grinders.

    PubMed

    Adami, Paolo Emilio; Delussu, Anna Sofia; Rodio, Angelo; Squeo, Maria Rosaria; Corsi, Loretta; Quattrini, Filippo Maria; Fattorini, Luigi; Bernardi, Marco

    2015-01-01

    This research on "America's Cup" grinders investigated the effects of a specific eight-week long-arm cranking ergometer (ACE) training on upper body (UB) aerobic fitness (ventilatory threshold - Tvent, respiratory compensation point- RCP, -oxygen uptake peak - VO₂peak) and high intensity working capacity. The training consisted of sessions carried out for 20-30 mins, three times per week, at an intensity between the UB-Tvent and UB-RCP, and replaced part of a typical lower limb aerobic training whilst maintaining the usual weekly schedule of callisthenics, resistance training and sailing. Seven sailors, including four grinders and three mastmen (age 30 ± 5.5 years, height 1.9 ± 0.04 m, body mass 102 ± 3.6 kg), were evaluated through both an ACE cardiopulmonary maximal exercise test (CPET) and an ACE all-out up to exhaustion exercise test, before and after the ACE training. UB aerobic fitness improved significantly: UB-VO₂peak increased from 4.29 ± 0.442 to 4.52 ± 0.522 l·min(-1) (6.4 ± 3.66%), VO₂ at UB-Tvent from 2.42 ± 0.282 to 2.97 ± 0.328 l·min(-1) (22.8 ± 5.09%) and VO₂ at UB-RCP from 3.25 ± 0.402 to 3.75 ± 0.352 l·min(-1) (16.1 ± 10.83%). Peak power at the ACE CPET increased from 351 ± 27.5 to 387 ± 33.5 W (10.5 ± 6.93%). The all-out test total mechanical work increased from 28.9 ± 2.35 to 40.1 ± 3.76 kJ (72.1 ± 4.67%). In conclusion, a high intensity aerobic ACE training can be effective in improving grinding performance by increasing UB aerobic fitness and all-out working capacity. PMID:25357134

  13. Avian leucocyte counting using the hemocytometer

    USGS Publications Warehouse

    Dein, F.J.; Wilson, A.; Fischer, D.; Langenberg, P.

    1994-01-01

    Automated methods for counting leucocytes in avian blood are not available because of the presence of nucleated erythrocytes and thrombocytes. Therefore, total white blood cell counts are performed by hand using a hemocytometer. The Natt and Herrick and the Unopette methods are the most common stain and diluent preparations for this procedure. Replicate hemocytometer counts using these two methods were performed on blood from four birds of different species. Cells present in each square of the hemocytometer were counted. Counting cells in the corner, side, or center hemocytometer squares produced statistically equivalent results; counting four squares per chamber provided a result similar to that obtained by counting nine squares; and the Unopette method was more precise for hemocytometer counting than was the Natt and Herrick method. The Unopette method is easier to learn and perform but is an indirect process, utilizing the differential count from a stained smear. The Natt and Herrick method is a direct total count, but cell identification is more difficult.

  14. Anaerobic digestion of dairy cattle manure autoheated by aerobic pretreatment

    SciTech Connect

    Achkari-Begdouri, A.

    1989-01-01

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

  15. The variability of light-harvesting complexes in aerobic anoxygenic phototrophs.

    PubMed

    Selyanin, Vadim; Hauruseu, Dzmitry; Koblížek, Michal

    2016-04-01

    Light-harvesting capacity was investigated in six species of aerobic anoxygenic phototrophic (AAP) bacteria using absorption spectroscopy, fluorescence emission spectroscopy, and pigment analyses. Aerobically grown AAP cells contained approx. 140-1800 photosynthetic reaction centers per cell, an order of magnitude less than purple non-sulfur bacteria grown semiaerobically. Three of the studied AAP species did not contain outer light-harvesting complexes, and the size of their reaction center core complexes (RC-LH1 core complexes) varied between 29 and 36 bacteriochlorophyll molecules. In AAP species containing accessory antennae, the size was frequently reduced, providing between 5 and 60 additional bacteriochlorophyll molecules. In Roseobacter litoralis, it was found that cells grown at a higher light intensity contained more reaction centers per cell, while the size of the light-harvesting complexes was reduced. The presented results document that AAP species have both the reduced number and size of light-harvesting complexes which is consistent with the auxiliary role of phototrophy in this bacterial group. PMID:26482589

  16. Laboratory evaluation of bioaugmentation for aerobic treatment of RDX in groundwater.

    PubMed

    Fuller, Mark E; Hatzinger, Paul B; Condee, Charles W; Andaya, Christina; Vainberg, Simon; Michalsen, Mandy M; Crocker, Fiona H; Indest, Karl J; Jung, Carina M; Eaton, Hillary; Istok, Jonathan D

    2015-02-01

    The potential for bioaugmentation with aerobic explosive degrading bacteria to remediate hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) contaminated aquifers was demonstrated. Repacked aquifer sediment columns were used to examine the transport and RDX degradation capacity of the known RDX degrading bacterial strains Gordonia sp. KTR9 (modified with a kanamycin resistance gene) Pseudomonas fluorescens I-C, and a kanamycin resistant transconjugate Rhodococcus jostii RHA1 pGKT2:Km+. All three strains were transported through the columns and eluted ahead of the conservative bromide tracer, although the total breakthrough varied by strain. The introduced cells responded to biostimulation with fructose (18 mg L(-1), 0.1 mM) by degrading dissolved RDX (0.5 mg L(-1), 2.3 µM). The strains retained RDX-degrading activity for at least 6 months following periods of starvation when no fructose was supplied to the column. Post-experiment analysis of the soil indicated that the residual cells were distributed along the length of the column. When the strains were grown to densities relevant for field-scale application, the cells remained viable and able to degrade RDX for at least 3 months when stored at 4 °C. These results indicate that bioaugmentation may be a viable option for treating RDX in large dilute aerobic plumes. PMID:25503243

  17. Evaluation of microbial transport during aerobic bioaugmentation of an RDX-contaminated aquifer.

    PubMed

    Crocker, Fiona H; Indest, Karl J; Jung, Carina M; Hancock, Dawn E; Fuller, Mark E; Hatzinger, Paul B; Vainberg, Simon; Istok, Jonathan D; Wilson, Edward; Michalsen, Mandy M

    2015-11-01

    In situ bioaugmentation with aerobic hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)-degrading bacteria is being considered for treatment of explosives-contaminated groundwater at Umatilla Chemical Depot, Oregon (UMCD). Two forced-gradient bacterial transport tests of site groundwater containing chloride or bromide tracer and either a mixed culture of Gordonia sp. KTR9 (xplA (+)Km(R)), Rhodococcus jostii RHA1 (pGKT2 transconjugant; xplA (+)Km(R)) and Pseudomonas fluorescens I-C (xenB (+)), or a single culture of Gordonia sp. KTR9 (xplA (+); i.e. wild-type) were conducted at UMCD. Groundwater monitoring evaluated cell viability and migration in the injection well and downgradient monitoring wells. Enhanced degradation of RDX was not evaluated in these demonstrations. Quantitative PCR analysis of xplA, the kanamycin resistance gene (aph), and xenB indicated that the mixed culture was transported at least 3 m within 2 h of injection. During a subsequent field injection of bioaugmented groundwater, strain KTR9 (wild-type) migrated up to 23-m downgradient of the injection well within 3 days. Thus, the three RDX-degrading strains were effectively introduced and transported within the UMCD aquifer. This demonstration represents an innovative application of bioaugmentation to potentially enhance RDX biodegradation in aerobic aquifers. PMID:26438043

  18. Simultaneous heterotrophic nitrification and aerobic denitrification by the marine origin bacterium Pseudomonas sp. ADN-42.

    PubMed

    Jin, Ruofei; Liu, Tianqi; Liu, Guangfei; Zhou, Jiti; Huang, Jianyu; Wang, Aijie

    2015-02-01

    Recent research has highlighted the existence of some bacteria that are capable of performing heterotrophic nitrification and have a phenomenal ability to denitrify their nitrification products under aerobic conditions. A high-salinity-tolerant strain ADN-42 was isolated from Hymeniacidon perleve and found to display high heterotrophic ammonium removal capability. This strain was identified as Pseudomonas sp. via 16S rRNA gene sequence analysis. Gene cloning and sequencing analysis indicated that the bacterial genome contains N2O reductase function (nosZ) gene. NH3-N removal rate of ADN-42 was very high. And the highest removal rate was 6.52 mg/L · h in the presence of 40 g/L NaCl. Under the condition of pure oxygen (DO >8 mg/L), NH3-N removal efficiency was 56.9 %. Moreover, 38.4 % of oxygen remained in the upper gas space during 72 h without greenhouse gas N2O production. Keeping continuous and low level of dissolved oxygen (DO <3 mg/L) was helpful for better denitrification performance. All these results indicated that the strain has heterotrophic nitrification and aerobic denitrification abilities, which guarantee future application in wastewater treatment. PMID:25432342

  19. Aerobic Exercise Program Reduces Anger Expression Among Overweight Children

    PubMed Central

    Tkacz, Joseph; Young-Hyman, Deborah; Boyle, Colleen A.; Davis, Catherine L.

    2009-01-01

    This study tested the effect of a structured aerobic exercise program on anger expression in healthy overweight children. Overweight, sedentary children were randomly assigned to an aerobic exercise program or a no-exercise control condition. All children completed the Pediatric Anger Expression Scale at baseline and posttest. Anger Out and Anger Expression scores were lower for the exercise condition at posttest. Fitness improvements contributed significantly to final models, and points earned for adherence correlated negatively with posttest Anger Out. An aerobic exercise program might be an effective strategy to reduce anger expression, including reduction of aggressive behavior, in overweight children. PMID:19168916

  20. 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.

  1. Evaluation of Biodegradability of Waste Before and After Aerobic Treatment

    NASA Astrophysics Data System (ADS)

    Suchowska-Kisielewicz, Monika; Jędrczak, Andrzej; Sadecka, Zofia

    2014-12-01

    An important advantage of use of an aerobic biostabilization of waste prior to its disposal is that it intensifies the decomposition of the organic fraction of waste into the form which is easily assimilable for methanogenic microorganisms involved in anaerobic decomposition of waste in the landfill. In this article it is presented the influence of aerobic pre-treatment of waste as well as leachate recirculation on susceptibility to biodegradation of waste in anaerobic laboratory reactors. The research has shown that in the reactor with aerobically treated waste stabilized with recilculation conversion of the organic carbon into the methane is about 45% higher than in the reactor with untreated waste stabilized without recirculation.

  2. Facial bacterial infections: folliculitis.

    PubMed

    Laureano, Ana Cristina; Schwartz, Robert A; Cohen, Philip J

    2014-01-01

    Facial bacterial infections are most commonly caused by infections of the hair follicles. Wherever pilosebaceous units are found folliculitis can occur, with the most frequent bacterial culprit being Staphylococcus aureus. We review different origins of facial folliculitis, distinguishing bacterial forms from other infectious and non-infectious mimickers. We distinguish folliculitis from pseudofolliculitis and perifolliculitis. Clinical features, etiology, pathology, and management options are also discussed. PMID:25441463

  3. Reduction of Salmonella on chicken breast fillets stored under aerobic or modified atmosphere packaging by the application of lytic bacteriophage preparation SalmoFreshTM.

    PubMed

    Sukumaran, Anuraj T; Nannapaneni, Rama; Kiess, Aaron; Sharma, Chander Shekhar

    2016-03-01

    The present study evaluated the efficacy of recently approved Salmonella lytic bacteriophage preparation (SalmoFresh™) in reducing Salmonella on chicken breast fillets, as a surface and dip application. The effectiveness of phage in combination with modified atmosphere packaging (MAP) and the ability of phage preparation in reducing Salmonella on chicken breast fillets at room temperature was also evaluated. Chicken breast fillets inoculated with a cocktail of Salmonella Typhimurium, S. Heidelberg, and S. Enteritidis were treated with bacteriophage (10(9) PFU/mL) as either a dip or surface treatment. The dip-treated samples were stored at 4°C aerobically and the surface-treated samples were stored under aerobic and MAP conditions (95% CO2/5% O2) at 4°C for 7 d. Immersion of Salmonella-inoculated chicken breast fillets in bacteriophage solution reduced Salmonella (P < 0.05) by 0.7 and 0.9 log CFU/g on d 0 and d 1 of storage, respectively. Surface treatment with phage significantly (P < 0.05) reduced Salmonella by 0.8, 0.8, and 1 log CFU/g on d 0, 1, and 7 of storage, respectively, under aerobic conditions. Higher reductions in Salmonella counts were achieved on chicken breast fillets when the samples were surface treated with phage and stored under MAP conditions. The Salmonella counts were reduced by 1.2, 1.1, and 1.2 log CFU/g on d 0, 1, and 7 of storage, respectively. Bacteriophage surface application on chicken breast fillets stored at room temperature reduced the Salmonella counts by 0.8, 0.9, and 0.4 log CFU/g after 0, 4, and 8 h, respectively, compared to the untreated positive control. These findings indicate that lytic phage preparation was effective in reducing Salmonella on chicken breast fillets stored under aerobic and modified atmosphere conditions. PMID:26706362

  4. Demonstrating Bacterial Flagella.

    ERIC Educational Resources Information Center

    Porter, John R.; And Others

    1992-01-01

    Describes an effective laboratory method for demonstrating bacterial flagella that utilizes the Proteus mirabilis organism and a special harvesting technique. Includes safety considerations for the laboratory exercise. (MDH)

  5. The Role of Aerobic and Anaerobic Training Programs on CD(34+) Stem Cells and Chosen Physiological Variables.

    PubMed

    Shalaby, Mohammed Nader; Saad, Mohammed; Akar, Samy; Reda, Mubarak Abdelreda Ali; Shalgham, Ahmed

    2012-12-01

    Exercise is one of the most powerful non-pharmacological strategies, which can affect nearly all cells and organs in the body. Changes in the behavior of adult stem cells have been shown to occur in response to exercise. Exercise may act on regenerative potential of tissues by altering the ability to generate new stem cells and differentiated cells that are able to carry out tissue specific functions. The purpose of this study was to reveal the role of aerobic and anaerobic training programs on CD34+ Stem Cells and chosen physiological variables. Twenty healthy male athletes aged 18-24 years were recruited for this study. Healthy low active males and BMI matched participants (n=10) aged 20-22 years were recruited as controls. Aerobic and anaerobic training programs for 12 weeks were conducted. VO2max pulse observation was carried out using the Astrand Rhyming protocol. RBCs, WBCs, HB and hematocrit were estimated using a coulter counter, lactate by the Accusport apparatus, CD34+ stem cells by flow cytometry. VO2max was increased significantly in case of the aerobic training program compared to anaerobic one (62±2.2 ml/kg/min vs. 54±2.1 ml/kg/min). Haemotological values increased significantly in the anaerobic program when compared to the aerobic one, RBCs (5.3±0.3 and 4.9±0.2 mln/ul), WBCs (6.6±0.5 and 6.1±0.4 thous/ul), HB (15.4±0.4 and 14.2±0.5 g/de), Hematocrit (4.6±1.2 and 4.4±1.1 %), CD34+ stem cells count increased significantly in case of the anaerobic program compared to the aerobic (251.6±21.64 and 130±14.61) and sedentary one (172±24.10). These findings suggest that anaerobic training programs provoke better adaptation to exercise and stem cell counts may differ between trained and sedentary subjects. Circulating immature cells are likely to be involved in angiogenesis and repair process, both mechanisms being associated with strenuous exercise. Knowledge of the physiological effects of training on stem cells might be of potential clinical

  6. Structure-toxicity assessment of metabolites of the aerobic bacterial transformation of substituted naphthalenes

    SciTech Connect

    LeBlond, J.D.; Applegate, B.M.; Menn, F.M.; Schultz, T.W.; Sayler, G.S.

    2000-05-01

    Pseudomonas fluorescens 5R, a naphthalene-degrading bacterium isolated from manufactured gas plant soil contaminated with polycyclic aromatic hydrocarbons, was examined for its degradative capacity of a number of substituted naphthalenes. In general, those compounds substituted on only one ring with an electrically neutral substituent were found to be transformed primarily to substituted salicylic acids according to the classical (NAH7) naphthalene dioxygenase-initiated upper pathway reactions of the naphthalene degradative pathway (i.e., the NAH system). Dimethylnaphthalenes with a substituent on each ring, and certain halogenated naphthalenes, were transformed via a monohydroxylation reaction to form hydroxylated dead-end products. Of the substituted salicylic acids examined, only 3- and 4-methylsalicylic acid, the respective products of the degradation of 1- and 2-methylnaphthalene, were further degraded by salicylate hydroxylase and catechol 2,3-dioxygenase, the first two enzymes of the NAH lower pathway. Using the Tetrahymena pyriformis acute toxicity assay, many of the monohydroxylated products of incomplete biodegradation were found to be polar narcotics. Substituted salicylic acids that are not further degraded by the NAH lower pathway were found to be toxic via carboxylic acid narcosis.

  7. AEROBIC DEGRADATION OF DINITROTOLUENES AND PATHWAY FOR BACTERIAL DEGRADATION OF 2,6-DINITROTOLUENE

    EPA Science Inventory

    An oxidative pathway for the mineralization of 2,4-dinitrotoluene (2,4-DNT) by Burkhoderia sp. strain DNT has been reported previously. We report here the isolation of additional strains with the ability to mineralize dinitrotoluene (2,6-DNT) by a different pathway. Burkhoderia ...

  8. Effects of a Rebound Exercise Training Program on Aerobic Capacity and Body Composition.

    ERIC Educational Resources Information Center

    Tomassoni, Teresa L.; And Others

    1985-01-01

    This study was designed to determine if aerobic dancing on rebound exercise equipment (minitrampolines) is an effective way to improve aerobic capacity and body composition. Although aerobic capacity improved, percent body fat did not change. Results were similar to those produced by conventional aerobic dance programs of like intensity. (MT)

  9. 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…

  10. Statistical aspects of point count sampling

    USGS Publications Warehouse

    Barker, R.J.; Sauer, J.R.

    1995-01-01

    The dominant feature of point counts is that they do not census birds, but instead provide incomplete counts of individuals present within a survey plot. Considering a simple model for point count sampling, we demon-strate that use of these incomplete counts can bias estimators and testing procedures, leading to inappropriate conclusions. A large portion of the variability in point counts is caused by the incomplete counting, and this within-count variation can be confounded with ecologically meaningful varia-tion. We recommend caution in the analysis of estimates obtained from point counts. Using; our model, we also consider optimal allocation of sampling effort. The critical step in the optimization process is in determining the goals of the study and methods that will be used to meet these goals. By explicitly defining the constraints on sampling and by estimating the relationship between precision and bias of estimators and time spent counting, we can predict the optimal time at a point for each of several monitoring goals. In general, time spent at a point will differ depending on the goals of the study.

  11. Identification of CSF fistulas by radionuclide counting

    SciTech Connect

    Yamamoto, Y.; Kunishio, K.; Sunami, N.; Yamamoto, Y.; Satoh, T.; Suga, M.; Asari, S. )

    1990-07-01

    A radionuclide counting method, performed with the patient prone and the neck flexed, was used successfully to diagnose CSF rhinorrhea in two patients. A normal radionuclide ratio (radionuclide counts in pledget/radionuclide counts in 1-ml blood sample) was obtained in 11 normal control subjects. Significance was determined to be a ratio greater than 0.37. Use of radionuclide counting method of determining CSF rhinorrhea is recommended when other methods have failed to locate a site of leakage or when posttraumatic meningitis suggests subclinical CSF rhinorrhea.

  12. Effect of counting errors on immunoassay precision

    SciTech Connect

    Klee, G.G.; Post, G. )

    1989-07-01

    Using mathematical analysis and computer simulation, we studied the effect of gamma scintillation counting error on two radioimmunoassays (RIAs) and an immunoradiometric assay (IRMA). To analyze the propagation of the counting errors into the estimation of analyte concentration, we empirically derived parameters for logit-log data-reduction models for assays of digoxin and triiodothyronine (RIAs) and ferritin (IRMA). The component of the analytical error attributable to counting variability, when expressed as a CV of the analyte concentration, decreased approximately linearly with the inverse of the square root of the maximum counts bound. Larger counting-error CVs were found at lower concentrations for both RIAs and the IRMA. Substantially smaller CVs for overall assay were found when the maximum counts bound progressively increased from 500 to 10,000 counts, but further increases in maximum bound counts resulted in little decrease in overall assay CV except when very low concentrations of analyte were being measured. Therefore, RIA and IRMA systems based in duplicate determinations having at least 10,000 maximum counts bound should have adequate precision, except possibly at very low concentrations.

  13. Vector perturbations of galaxy number counts

    NASA Astrophysics Data System (ADS)

    Durrer, Ruth; Tansella, Vittorio

    2016-07-01

    We derive the contribution to relativistic galaxy number count fluctuations from vector and tensor perturbations within linear perturbation theory. Our result is consistent with the the relativistic corrections to number counts due to scalar perturbation, where the Bardeen potentials are replaced with line-of-sight projection of vector and tensor quantities. Since vector and tensor perturbations do not lead to density fluctuations the standard density term in the number counts is absent. We apply our results to vector perturbations which are induced from scalar perturbations at second order and give numerical estimates of their contributions to the power spectrum of relativistic galaxy number counts.

  14. Low Background Counting at LBNL

    DOE PAGESBeta

    Smith, A. R.; Thomas, K. J.; Norman, E. B.; Chan, Y. D.; Lesko, K. T.; Hurley, D. L.

    2015-03-24

    The Low Background Facility (LBF) at Lawrence Berkeley National Laboratory in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background cave and remotely at an underground location that historically has operated underground in Oroville, CA, but has recently been relocated to the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K)more » or common cosmogenic/anthropogenic products, as well as active screening via Neutron Activation Analysis for specific applications. The LBF also provides hosting services for general R&D testing in low background environments on the surface or underground for background testing of detector systems or similar prototyping. A general overview of the facilities, services, and sensitivities is presented. Recent activities and upgrades will also be presented, such as the completion of a 3π anticoincidence shield at the surface station and environmental monitoring of Fukushima fallout. The LBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.« less

  15. Low Background Counting at LBNL

    SciTech Connect

    Smith, A. R.; Thomas, K. J.; Norman, E. B.; Chan, Y. D.; Lesko, K. T.; Hurley, D. L.

    2015-03-24

    The Low Background Facility (LBF) at Lawrence Berkeley National Laboratory in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background cave and remotely at an underground location that historically has operated underground in Oroville, CA, but has recently been relocated to the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products, as well as active screening via Neutron Activation Analysis for specific applications. The LBF also provides hosting services for general R&D testing in low background environments on the surface or underground for background testing of detector systems or similar prototyping. A general overview of the facilities, services, and sensitivities is presented. Recent activities and upgrades will also be presented, such as the completion of a 3π anticoincidence shield at the surface station and environmental monitoring of Fukushima fallout. The LBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.

  16. Photon counting with an EMCCD

    NASA Astrophysics Data System (ADS)

    Daigle, Olivier; Blais-Ouellette, Sébastien

    2010-01-01

    In order to make faint flux imaging efficient with an EMCCD, the Clock Induced Charges (CIC) must be reduced to a minimum. Some techniques were proposed to reduce the CIC but until now, neither commercially available CCD controller nor commercial cameras were able to implement them and get satisfying results. CCCP, the CCD Controller for Counting Photons, has been designed with the aim of reducing the CIC generated when an EMCCD is read out. It is optimized for driving EMCCDs at high speed (>= 10MHz), but may be used also for driving conventional CCDs (or the conventional output of an EMCCD) at high, moderate, or low speed. This new controller provides an arbitrary clock generator, yielding a timing resolution of ~20 ps and a voltage resolution of ~2mV of the overlap of the clocks used to drive the EMCCD. The frequency components of the clocks can be precisely controlled, and the inter-clock capacitance effect of the CCD can be nulled to avoid overshoots and undershoots. Using this controller, CIC levels as low as 0.001 - 0.002 e per pixel per frame were measured on a 512×512 CCD97 operating in inverted mode, at an EM gain of ~2000. This is 5 to 10 times less than what is usually seen in commercial EMCCD cameras using the same EMCCD chip.

  17. Low Background Counting at LBNL

    NASA Astrophysics Data System (ADS)

    Smith, A. R.; Thomas, K. J.; Norman, E. B.; Chan, Y. D.; Lesko, K. T.; Hurley, D. L.

    The Low Background Facility (LBF) at Lawrence Berkeley National Laboratory in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background cave and remotely at an underground location that historically has operated underground in Oroville, CA, but has recently been relocated to the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products, as well as active screening via Neutron Activation Analysis for specific applications. The LBF also provides hosting services for general R&D testing in low background environments on the surface or underground for background testing of detector systems or similar prototyping. A general overview of the facilities, services, and sensitivities is presented. Recent activities and upgrades will also be presented, such as the completion of a 3π anticoincidence shield at the surface station and environmental monitoring of Fukushima fallout. The LBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.

  18. Respiration and respiratory enzyme activity in aerobic and anaerobic cultures of the marine denitrifying bacterium, Pseudomonas perfectomarinus

    NASA Astrophysics Data System (ADS)

    Packard, T. T.; Garfield, P. C.; Martinez, R.

    1983-03-01

    Oxygen consumption, nitrate reduction, respiratory electron transport activity, and nitrate reductase activity were measured in aerobic and anaerobic cultures of the marine bacterium, Pseudomonas perfectomarinus. The respiratory electron transport activity was closely correlated with oxygen consumption ( r = 0.98) in aerobic cultures and nearly as well correlated with nitrate reductase activity ( r = 0.91) and nitrate reduction ( r = 0.85) in anaerobic cultures. It was also well correlated with biomass in both aerobic ( r = 0.99) and anaerobic ( r = 0.94) cultures supporting the use of tetrazolium reduction as an index of living biomass. Time courses of nitrate and nitrate in the anaerobic cultures demonstrated that at nitrate concentrations above 1 mM, denitrification proceeds stepwise. Time courses of pH in anaerobic cultures revealed a rise from 7 to 8.5 during nitrite reduction indicating net proton utilization. This proton utilization is predicted by the stoichiometry of denitrification. Although the experiments were not under 'simulated in situ' conditions, the results are relevant to studies of denitrification, to bacterial ATP production, and to the respiratory activity of marine plankton in the ocean.

  19. Ecophysiology of Defluviicoccus-related tetrad-forming organisms in an anaerobic-aerobic activated sludge process.

    PubMed

    Wong, Man-Tak; Liu, Wen-Tso

    2007-06-01

    A group of uncultured tetrad-forming organisms (TFOs) was enriched in an acetate-fed anaerobic-aerobic sequencing membrane bioreactor showing deteriorated enhanced biological phosphorus removal capacity. Based on 16S rRNA gene clone library and fluorescence in situ hybridization (FISH) analyses, these TFOs were identified as novel members of the Defluviicoccus cluster in the Alphaproteobacteria, accounting for 90 +/- 5% of the EUBmix FISH-detectable bacterial cell area in the reactor biomass. Microautoradiography in combination with FISH and polyhydroxyalkanoate (PHA) staining revealed that these Defluviicoccus-related TFOs could take up and transform acetate, lactate, propionate and pyruvate, but not aspartic acid and glucose, into PHA under anaerobic conditions. In contrast, under continuous anaerobic-aerobic cultivation, Defluviicoccus vanus, the only cultured strain from the cluster, was able to take up glucose with concurrent glycogen consumption and PHA production under anaerobic conditions. Under subsequent aerobic conditions, the accumulated PHA was utilized and the biomass glycogen levels were restored. These findings not only re-confirmed these Defluviicoccus-related TFOs as glycogen-accumulating organisms, but also revealed unexpected levels of physiological, phylogenetic and morphological diversity among members of the Defluviicoccus cluster. PMID:17504486

  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. PMID:16477361