WorldWideScience

Sample records for anaerobic enrichment culture

  1. [Reductive Dechlorination of Trichloroethylene by Benzoate-Enriched Anaerobic Cultures].

    Science.gov (United States)

    Li, Jiang-wei; Yang, Xiao-yong; Hu, An-yi; Yu, Chang-ping

    2015-10-01

    Gas chromatography was used to monitor the reductive dechlorination of trichloroethylene (TCE) by anaerobic enrichment cultures with benzoate as the sole carbon source. The 454 pyrosequencing technique was used to investigate the microbial community and the real-time quantitative PCR was used to quantify the gene copies of Dehalococcoides spp. (DHC). The results showed that TCE was dechlorinated to vinyl chloride along with the formation of methane in 94 days. The anaerobic enrichment cultures exhibited a high diversity, which were classified into 16 phyla, 33 classes, 52 orders, 88 families and 129 genera, while 51.2% of them belonged to unclassified group, which inferred that there were a large portion of bacteria with unknown functional in this system. Degradation of TCE was accomplished by reductive dechlorinating and other functional populations, and the DHC which carried tceA gene could be the dominant reductive dechlorinating populations in the system. PMID:26841609

  2. A strict anaerobic extreme thermophilic hydrogen-producing culture enriched from digested household waste

    DEFF Research Database (Denmark)

    Karakashev, Dimitar Borisov; Kotay, Shireen Meher; Trably, Eric;

    2009-01-01

    The aim of this study was to enrich, characterize and identify strict anaerobic extreme thermophilic hydrogen (H-2) producers from digested household solid wastes. A strict anaerobic extreme thermophilic H-2 producing bacterial culture was enriched from a lab-scale digester treating household...... to the genera Bacillus and Clostridium. Relative abundance of the culture members, assessed by fluorescence in situ hybridization, were 87 +/- 5% and 13 +/- 5% for Bacillus and Clostridium, respectively. An extreme thermophilic, strict anaerobic, mixed microbial culture with H-2-producing potential was enriched...

  3. Enrichment culture of marine anaerobic ammonium oxidation (anammox) bacteria

    Institute of Scientific and Technical Information of China (English)

    GUAN Yong-jie

    2016-01-01

    The present study investigates the enrichment of anaerobic ammonium oxidation (anammox) bacteria in the marine environment using sediment samples obtained from the East China Sea and discusses the nitrogen removal efficiency of marine anammox bioreactor. Enrichment of anammox bacteria with simultaneous removal of nitrite and ammonium ions was observed in the Anaerobic Sequencing Batch Reactor under a total nitrogen loading rate of 0.37kg-N m-3day-1. In this study, The nitrogen removal efficiency was up to 80% and the molar-reaction ratio of ammonium, nitrite and nitrate was 1.0:1.22:0.22 which was a little different from a previously reported ratio of 1.0:1.32:0.26 in a freshwater system.

  4. Integrated biogas upgrading and hydrogen utilization in an anaerobic reactor containing enriched hydrogenotrophic methanogenic culture

    DEFF Research Database (Denmark)

    Luo, Gang; Angelidaki, Irini

    2012-01-01

    by PCR–DGGE. Nonetheless, they all belonged to the order Methanobacteriales, which can mediate hydrogenotrophic methanogenesis. Biogas upgrading was then tested in a thermophilic anaerobic reactor under various operation conditions. By continuous addition of hydrogen in the biogas reactor, high degree...... the existing natural gas grid. The current study presents a new biological method for biogas upgrading in a separate biogas reactor, containing enriched hydrogenotrophic methanogens and fed with biogas and hydrogen. Both mesophilic- and thermophilic anaerobic cultures were enriched to convert CO2 to CH4...... by addition of H2. Enrichment at thermophilic temperature (55°C) resulted in CO2 and H2 bioconversion rate of 320 mL CH4/(gVSS h), which was more than 60% higher than that under mesophilic temperature (37°C). Different dominant species were found at mesophilic- and thermophilic-enriched cultures, as revealed...

  5. Use of {gamma}-hexachlorocyclohexane as a terminal electron acceptor by an anaerobic enrichment culture

    Energy Technology Data Exchange (ETDEWEB)

    Elango, Vijai, E-mail: velango@g.clemson.edu [Hazardous Substance Research Center/South and Southwest, Louisiana State University, 3221 Patrick Taylor Hall, Baton Rouge, LA 70803 (United States); Kurtz, Harry D. [Department of Genetics and Biochemistry, Clemson University, 100 Jordan Hall, Clemson, SC 29634 (United States); Anderson, Christina; Freedman, David L. [Department of Environmental Engineering and Earth Sciences, Box 340919, Clemson University, Clemson, SC 29634-0919 (United States)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Use of {gamma}-hexachlorocyclohexane as a terminal electron acceptor was demonstrated. Black-Right-Pointing-Pointer H{sub 2} served as the electron donor for an enrichment culture that dechlorinated {gamma}-HCH. Black-Right-Pointing-Pointer H{sub 2} consumption for acetogenesis and methanogenesis stopped in HEPES media. Black-Right-Pointing-Pointer Addition of vancomycin significantly slowed the rate of {gamma}-HCH dechlorination. Black-Right-Pointing-Pointer Previously identified chlororespiring microbes were not detected in the enrichment. - Abstract: The use of {gamma}-hexachlorocyclohexane (HCH) as a terminal electron acceptor via organohalide respiration was demonstrated for the first time with an enrichment culture grown in a sulfate-free HEPES-buffered anaerobic mineral salts medium. The enrichment culture was initially developed with soil and groundwater from an industrial site contaminated with HCH isomers, chlorinated benzenes, and chlorinated ethenes. When hydrogen served as the electron donor, 79-90% of the electron equivalents from hydrogen were used by the enrichment culture for reductive dechlorination of the {gamma}-HCH, which was provided at a saturation concentration of approximately 10 mg/L. Benzene and chlorobenzene were the only volatile transformation products detected, accounting for 25% and 75% of the {gamma}-HCH consumed (on a molar basis), respectively. The enrichment culture remained active with only hydrogen as the electron donor and {gamma}-HCH as the electron acceptor through several transfers to fresh mineral salts medium for more than one year. Addition of vancomycin to the culture significantly slowed the rate of {gamma}-HCH dechlorination, suggesting that a Gram-positive organism is responsible for the reduction of {gamma}-HCH. Analysis of the {gamma}-HCH dechlorinating enrichment culture did not detect any known chlororespiring genera, including Dehalobacter. In bicarbonate-buffered medium

  6. Integrated biogas upgrading and hydrogen utilization in an anaerobic reactor containing enriched hydrogenotrophic methanogenic culture.

    Science.gov (United States)

    Luo, Gang; Angelidaki, Irini

    2012-11-01

    Biogas produced by anaerobic digestion, is mainly used in a gas motor for heat and electricity production. However, after removal of CO(2) , biogas can be upgraded to natural gas quality, giving more utilization possibilities, such as utilization as autogas, or distant utilization by using the existing natural gas grid. The current study presents a new biological method for biogas upgrading in a separate biogas reactor, containing enriched hydrogenotrophic methanogens and fed with biogas and hydrogen. Both mesophilic- and thermophilic anaerobic cultures were enriched to convert CO(2) to CH(4) by addition of H(2) . Enrichment at thermophilic temperature (55°C) resulted in CO(2) and H(2) bioconversion rate of 320 mL CH(4) /(gVSS h), which was more than 60% higher than that under mesophilic temperature (37°C). Different dominant species were found at mesophilic- and thermophilic-enriched cultures, as revealed by PCR-DGGE. Nonetheless, they all belonged to the order Methanobacteriales, which can mediate hydrogenotrophic methanogenesis. Biogas upgrading was then tested in a thermophilic anaerobic reactor under various operation conditions. By continuous addition of hydrogen in the biogas reactor, high degree of biogas upgrading was achieved. The produced biogas had a CH(4) content, around 95% at steady-state, at gas (mixture of biogas and hydrogen) injection rate of 6 L/(L day). The increase of gas injection rate to 12 L/(L day) resulted in the decrease of CH(4) content to around 90%. Further study showed that by decreasing the gas-liquid mass transfer by increasing the stirring speed of the mixture the CH(4) content was increased to around 95%. Finally, the CH(4) content around 90% was achieved in this study with the gas injection rate as high as 24 L/(L day).

  7. Inhibition of anaerobic ammonium oxidizing (anammox) enrichment cultures by substrates, metabolites and common wastewater constituents.

    Science.gov (United States)

    Carvajal-Arroyo, José M; Sun, Wenjie; Sierra-Alvarez, Reyes; Field, Jim A

    2013-03-01

    Anaerobic ammonium oxidation (anammox) is an emerging technology for nitrogen removal that provides a more environmentally sustainable and cost effective alternative compared to conventional biological treatment methods. The objective of this study was to investigate the inhibitory impact of anammox substrates, metabolites and common wastewater constituents on the microbial activity of two different anammox enrichment cultures (suspended and granular), both dominated by bacteria from the genus Brocadia. Inhibition was evaluated in batch assays by comparing the N(2) production rates in the absence or presence of each compound supplied in a range of concentrations. The optimal pH was 7.5 and 7.3 for the suspended and granular enrichment cultures, respectively. Among the substrates or products, ammonium and nitrate caused low to moderate inhibition, whereas nitrite caused almost complete inhibition at concentrations higher than 15 mM. The intermediate, hydrazine, either stimulated or caused low inhibition of anammox activity up to 3mM. Of the common constituents in wastewater, hydrogen sulfide was the most severe inhibitor, with 50% inhibitory concentrations (IC(50)) as low as 0.03 mM undissociated H(2)S. Dissolved O(2) showed moderate inhibition (IC(50)=2.3-3.8 mg L(-1)). In contrast, phosphate and salinity (NaCl) posed very low inhibition. The suspended- and granular anammox enrichment cultures had similar patterns of response to the various inhibitory stresses with the exception of phosphate. The findings of this study provide comprehensive insights on the tolerance of the anammox process to a wide variety of potential inhibiting compounds.

  8. Ammonia tolerant enriched methanogenic cultures as bioaugmentation inocula to alleviate ammonia inhibition in continuous anaerobic reactors

    DEFF Research Database (Denmark)

    Fotidis, Ioannis; Wang, Han; Angelidaki, Irini

    . The bioaugmentation was performed without pausing the continuous operation of the CSTR reactor and without excluding the ammonia-rich substrate from the feedstock. Thus, bioaugmentation with mixed methanogenic cultures could potentially support the development of an efficient and cost-effective biomethanation process...... of a pure culture, to be used as bioaugmentation inoculum, poses technical difficulties due to the required sterile conditions and the special growing media. On the contrary acclimatized enrichment methanogenic cultures have lower requirements to sterility. In the present study, we used an enriched ammonia...... tolerant methanogenic culture as potential bioaugmentation inoculum in a continuous stirred tank reactor (CSTR) operating under “inhibited steady-state”, triggered by high ammonia levels (5 g NH4+-N L-1). The results of the current study established for the first time that bioaugmentation of an enriched...

  9. Ammonia tolerant enriched methanogenic cultures as bioaugmentation inocula to alleviate ammonia inhibition in continuous anaerobic reactors

    DEFF Research Database (Denmark)

    Fotidis, Ioannis; Wang, Han; Angelidaki, Irini

    tolerant methanogenic culture as potential bioaugmentation inoculum in a continuous stirred tank reactor (CSTR) operating under “inhibited steady-state”, triggered by high ammonia levels (5 g NH4+-N L-1). The results of the current study established for the first time that bioaugmentation of an enriched...... ammonia tolerant methanogen in a CSTR reactor could completely alleviate the ammonia inhibitory effect. Furthermore, it was found that bioaugmentation with the enriched culture resulted in 25% higher methane production compared to when the bioaugmentation was achieved with pure methanogenic strains....... The bioaugmentation was performed without pausing the continuous operation of the CSTR reactor and without excluding the ammonia-rich substrate from the feedstock. Thus, bioaugmentation with mixed methanogenic cultures could potentially support the development of an efficient and cost-effective biomethanation process...

  10. Microbial dynamics in anaerobic enrichment cultures degrading di-n-butyl phthalic acid ester

    DEFF Research Database (Denmark)

    Trably, Eric; Batstone, Damien J.; Christensen, Nina;

    2008-01-01

    , a microorganism described previously as an anaerobic benzaldehyde degrader. Within the archaeal community, there was a shift between two different species of the genus Methanosaeta sp., indicating a highly specific impact of DBP or degradation products on archaeal species. RNA-directed probes were designed from...

  11. Establishment and Characterization of an Anaerobic Thermophilic (55 degrees C) Enrichment Culture Degrading Long-Chain Fatty Acids

    DEFF Research Database (Denmark)

    Angelidaki, Irini; Ahring, Birgitte Kiær

    1995-01-01

    A thermophilic, long-chain fatty acid-oxidizing culture was enriched. Stearate was used as the substrate, and methane and carbon dioxide were the sole end products. Cultivation was possible only when a fed-batch system was used or with addition of activated carbon or bentonite. The enrichment...

  12. Enrichment of anaerobic syngas converting bacteria from bioreactor sludges

    NARCIS (Netherlands)

    Alves, J.I.; Stams, A.J.M.; Plugge, C.M.; Alves, M.M.; Sousa, D.Z.

    2013-01-01

    Thermophilic (55°C) anaerobic microbial communities were enriched with a synthetic syngas mixture (composed of CO, H2 and CO2 ) or with CO alone. Cultures T-Syn and T-CO were incubated and successively transferred with syngas (16 transfers) or CO (9 transfers), respectively, with increasing CO parti

  13. Accelerated methanogenesis from effluents of hydrogen-producing stage in anaerobic digestion by mixed cultures enriched with acetate and nano-sized magnetite particles.

    Science.gov (United States)

    Yang, Zhiman; Xu, Xiaohui; Guo, Rongbo; Fan, Xiaolei; Zhao, Xiaoxian

    2015-08-01

    Potential for paddy soil enrichments obtained in the presence of nano-sized magnetite particles (named as PSEM) to promote methane production from effluents of hydrogen-producing stage in two-stage anaerobic digestion was investigated. The results showed that the addition of magnetite significantly accelerated methane production from acetate in a dose-independent manner. The results from high-throughput sequencing analysis revealed that Rhodocyclaceae-related species were selectively enriched, which were likely the key players for conversion of acetate to methane in PSEM. Compared to the paddy soil enrichments obtained in the absence of magnetite (named as PSEC), the maximum methane production rate in PSEM was significantly higher (1.5-5.5times higher for the artificial medium and 0.2-1.7times higher for the effluents). The accelerated methane production from the effluents indicated remarkably application potential of PSEM for improving performance of anaerobic digestion. PMID:25935393

  14. Enrichment of high ammonia tolerant methanogenic culture

    DEFF Research Database (Denmark)

    Fotidis, Ioannis; Karakashev, Dimitar Borisov; Proietti, Nicolas;

    of the current study was to isolate and identify methanogenic cultures tolerant to high ammonia concentrations. A mixed methanogenic population was stepwise exposed to ammonia concentrations (1 to 9.26 g NH4+-N L-1) during an enrichment process with successive batch cultivations. The methanogenic population...... was derived from a full scale biogas reactor (Hashøj, Denmark), fed with 75% animal manure and 25% food industries organic waste. Basal anaerobic medium was used for the enrichment along with sodium acetate (1 g HAc L-1) as a carbon source. Fluorescence insitu hybridization (FISH) was used to determine...... microbial community composition. The outcome of the enrichment process was a mesophilic aceticlastic methanogenic enriched culture able to withstand high ammonia loads and utilize acetate and form methane stoichiometrically. FISH analysis showed that the methanogens of the enriched culture belonged...

  15. Anaerobic degradation of benzene by enriched consortia with humic acids as terminal electron acceptors

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes, Francisco J., E-mail: fjcervantes@ipicyt.edu.mx [Division de Ciencias Ambientales, Instituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT), Camino a la Presa San Jose 2055, Col. Lomas 4a. Seccion, San Luis Potosi, SLP, 78216 Mexico (Mexico); Mancilla, Ana Rosa; Toro, E. Emilia Rios-del [Division de Ciencias Ambientales, Instituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT), Camino a la Presa San Jose 2055, Col. Lomas 4a. Seccion, San Luis Potosi, SLP, 78216 Mexico (Mexico); Alpuche-Solis, Angel G.; Montoya-Lorenzana, Lilia [Division de Biologia Molecular, Instituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT), Camino a la Presa San Jose 2055, Col. Lomas 4a. Seccion, San Luis Potosi, SLP, 78216 Mexico (Mexico)

    2011-11-15

    Highlights: {yields} Enriched consortia were able to couple the anaerobic degradation of benzene to the reduction of humic acids. {yields} Electron-equivalents derived from anaerobic benzene oxidation were highly recovered as reduced humic acids. {yields} Several species from classes {beta}-, {delta}- and {gamma}-Proteobacteria were enriched during the anaerobic degradation of benzene. - Abstract: The anaerobic degradation of benzene coupled to the reduction of humic acids (HA) was demonstrated in two enriched consortia. Both inocula were able to oxidize benzene under strict anaerobic conditions when the humic model compound, anthraquinone-2,6-disulfonate (AQDS), was supplied as terminal electron acceptor. An enrichment culture originated from a contaminated soil was also able to oxidize benzene linked to the reduction of highly purified soil humic acids (HPSHA). In HPSHA-amended cultures, 9.3 {mu}M of benzene were degraded, which corresponds to 279 {+-} 27 micro-electron equivalents ({mu}Eq) L{sup -1}, linked to the reduction of 619 {+-} 81 {mu}Eq L{sup -1} of HPSHA. Neither anaerobic benzene oxidation nor reduction of HPSHA occurred in sterilized controls. Anaerobic benzene oxidation did not occur in soil incubations lacking HPSHA. Furthermore, negligible reduction of HPSHA occurred in the absence of benzene. The enrichment culture derived from this soil was dominated by two {gamma}-Proteobacteria phylotypes. A benzene-degrading AQDS-reducing enrichment originated from a sediment sample showed the prevalence of different species from classes {beta}-, {delta}- and {gamma}-Proteobacteria. The present study provides clear quantitative demonstration of anaerobic degradation of benzene coupled to the reduction of HA.

  16. Highly enriched Betaproteobacteria growing anaerobically with p-xylene and nitrate

    DEFF Research Database (Denmark)

    Rotaru, Amelia-Elena; Probian, Christina; Wilkes, Heinz;

    2010-01-01

    The identity of the microorganisms capable of anaerobic p-xylene degradation under denitrifying conditions is hitherto unknown. Here, we report highly enriched cultures of freshwater denitrifying bacteria that grow anaerobically with p-xylene as the sole organic carbon source and electron donor. ....... Long curved rods, with 95% 16S rRNA gene sequence identity to Denitratisoma oestradiolicum, dominated the enrichment cultures (>91% of all cells), as detected by phylotype-specific probes. These Rhodocyclaceae microorganisms were distantly related to other denitrifying hydrocarbon...

  17. Carbohydrate-enriched cyanobacterial biomass as feedstock for bio-methane production through anaerobic digestion

    DEFF Research Database (Denmark)

    Markou, Giorgos; Angelidaki, Irini; Georgakakis, Dimitris

    2013-01-01

    The anaerobic digestion performance using carbohydrate-enriched biomass of Arthrospira platensis was studied. The carbohydrate enrichment was achieved after the cultivation of A. platensis under phosphorus limitation conditions. Three biomass compositions (60%, 40% and 20% carbohydrates content) ...

  18. Culture enriched molecular profiling of the cystic fibrosis airway microbiome.

    Science.gov (United States)

    Sibley, Christopher D; Grinwis, Margot E; Field, Tyler R; Eshaghurshan, Christina S; Faria, Monica M; Dowd, Scot E; Parkins, Michael D; Rabin, Harvey R; Surette, Michael G

    2011-01-01

    The microbiome of the respiratory tract, including the nasopharyngeal and oropharyngeal microbiota, is a dynamic community of microorganisms that is highly diverse. The cystic fibrosis (CF) airway microbiome refers to the polymicrobial communities present in the lower airways of CF patients. It is comprised of chronic opportunistic pathogens (such as Pseudomonas aeruginosa) and a variety of organisms derived mostly from the normal microbiota of the upper respiratory tract. The complexity of these communities has been inferred primarily from culture independent molecular profiling. As with most microbial communities it is generally assumed that most of the organisms present are not readily cultured. Our culture collection generated using more extensive cultivation approaches, reveals a more complex microbial community than that obtained by conventional CF culture methods. To directly evaluate the cultivability of the airway microbiome, we examined six samples in depth using culture-enriched molecular profiling which combines culture-based methods with the molecular profiling methods of terminal restriction fragment length polymorphisms and 16S rRNA gene sequencing. We demonstrate that combining culture-dependent and culture-independent approaches enhances the sensitivity of either approach alone. Our techniques were able to cultivate 43 of the 48 families detected by deep sequencing; the five families recovered solely by culture-independent approaches were all present at very low abundance (<0.002% total reads). 46% of the molecular signatures detected by culture from the six patients were only identified in an anaerobic environment, suggesting that a large proportion of the cultured airway community is composed of obligate anaerobes. Most significantly, using 20 growth conditions per specimen, half of which included anaerobic cultivation and extended incubation times we demonstrate that the majority of bacteria present can be cultured.

  19. Culture enriched molecular profiling of the cystic fibrosis airway microbiome.

    Directory of Open Access Journals (Sweden)

    Christopher D Sibley

    Full Text Available The microbiome of the respiratory tract, including the nasopharyngeal and oropharyngeal microbiota, is a dynamic community of microorganisms that is highly diverse. The cystic fibrosis (CF airway microbiome refers to the polymicrobial communities present in the lower airways of CF patients. It is comprised of chronic opportunistic pathogens (such as Pseudomonas aeruginosa and a variety of organisms derived mostly from the normal microbiota of the upper respiratory tract. The complexity of these communities has been inferred primarily from culture independent molecular profiling. As with most microbial communities it is generally assumed that most of the organisms present are not readily cultured. Our culture collection generated using more extensive cultivation approaches, reveals a more complex microbial community than that obtained by conventional CF culture methods. To directly evaluate the cultivability of the airway microbiome, we examined six samples in depth using culture-enriched molecular profiling which combines culture-based methods with the molecular profiling methods of terminal restriction fragment length polymorphisms and 16S rRNA gene sequencing. We demonstrate that combining culture-dependent and culture-independent approaches enhances the sensitivity of either approach alone. Our techniques were able to cultivate 43 of the 48 families detected by deep sequencing; the five families recovered solely by culture-independent approaches were all present at very low abundance (<0.002% total reads. 46% of the molecular signatures detected by culture from the six patients were only identified in an anaerobic environment, suggesting that a large proportion of the cultured airway community is composed of obligate anaerobes. Most significantly, using 20 growth conditions per specimen, half of which included anaerobic cultivation and extended incubation times we demonstrate that the majority of bacteria present can be cultured.

  20. Anaerobic Degradation of Chloroaromatic Compounds in Aquatic Sediments under a Variety of Enrichment Conditions †

    OpenAIRE

    Genthner, Barbara R. Sharak; Price, W. Allen; Pritchard, P H

    1989-01-01

    Anaerobic degradation of monochlorophenols and monochlorobenzoates in a variety of aquatic sediments was compared under four enrichment conditions. A broader range of compounds was degraded in enrichments inoculated with sediment exposed to industrial effluents. Degradation of chloroaromatic compounds was observed most often in methanogenic enrichments and in enrichments amended with 1 mM bromoethane sulfonic acid. Degradation was observed least often in enrichments with added nitrate or sulf...

  1. Effect of methanogenic substrates on anaerobic oxidation of methane and sulfate reduction by an anaerobic methanotrophic enrichment

    OpenAIRE

    Meulepas, R.J.W.; Jagersma, C.G.; Khadem, A.F.; Buisman, C.J.N.; Stams, A.J.M.; Lens, P. N. L.

    2010-01-01

    Anaerobic oxidation of methane (AOM) coupled to sulfate reduction (SR) is assumed to be a syntrophic process, in which methanotrophic archaea produce an interspecies electron carrier (IEC), which is subsequently utilized by sulfate-reducing bacteria. In this paper, six methanogenic substrates are tested as candidate-IECs by assessing their effect on AOM and SR by an anaerobic methanotrophic enrichment. The presence of acetate, formate or hydrogen enhanced SR, but did not inhibit AOM, nor did ...

  2. 一个硫酸盐还原细菌富集物对丁草胺的厌氧降解%Anaerobic degradation of butachlor by sulfate-reducing bacteria enrichment culture

    Institute of Scientific and Technical Information of China (English)

    叶央芳; 杜宇峰

    2000-01-01

    An enrichment culture of sulfate-reducing bacteria,capable of anaerabic degrading butachlor,was obtained.The degradation kinetics of butachlor by the enrichment culture was determined and the optimum concentration of butachlor,the optimum pH and temperature for degradation of butachlor were observed..%通过多次富集培养,得到一个能有效厌氧降解丁草胺的硫酸盐还原细菌(SRB)富集物,并对该富集物的生长动力学以及生长的最适丁草胺浓度、最适pH和最适温度作了探讨.

  3. Metabolic characteristics of an aerobe isolated from a methylotrophic methanogenic enrichment culture

    Indian Academy of Sciences (India)

    Stephen V Rapheal; K R Swaminathan; K Lalitha

    2003-03-01

    An anaerobic methylotrophic methanogenic enrichment culture, with sustained metabolic characteristics, including that of methanation for over a decade, was the choice of the present study on interspecies interactions. Growth and methanation by the enrichment were suppressed in the presence of antibiotics, and no methanogen grown on methanol could be isolated using stringent techniques. The present study confirmed syntrophic metabolic interactions in this enrichment with the isolation of a strain of Pseudomonas sp. The organism had characteristic metabolic versatility in metabolizing a variety of substrates including alcohols, aliphatic acids, amino acids, and sugars. Anaerobic growth was favoured with nitrate in the growth medium. Cells grown anaerobically with methanol, revealed maximal nitrate reductase activity. Constitutive oxidative activity of the membrane system emerged from the high-specific oxygen uptake and nitrate reductase activities of the aerobically and anerobically grown cells respectively. Cells grown anaerobically on various alcohols effectively oxidized methanol in the presence of flavins, cofactor FAD and the methanogenic cofactor F420, suggesting a constitutive alcohol oxidizing capacity. In cells grown anaerobically on methanol, the rate of methanol oxidation with F420 was three times that of FAD. Efficient utilization of alcohols in the presence of F420 is a novel feature of the present study. The results suggest that utilization of methanol by the mixed culture would involve metabolic interactions between the Pseudomonas sp. and the methanogen(s). Methylotrophic, methanogenic partnership involving an aerobe is a novel feature hitherto unreported among anaerobic syntrophic associations and is of ecological significance.

  4. Utilization of aminoaromatic acids by a methanogenic enrichment culture and by a novel Citrobacter freundii strain

    NARCIS (Netherlands)

    Savelieva, O.; Kotova, I.; Roelofsen, W.; Stams, A.J.M.; Netrusov, A.

    2004-01-01

    Following incubation of mesophilic methanogenic floccular sludge from a lab-scale upflow anaerobic sludge bed reactor used to treat cattle manure wastewater, a stable 5-aminosalicylate-degrading enrichment culture was obtained. Subsequently, a Citrobacter freundii strain, WA1, was isolated from the

  5. Mineralization of Trichloroethylene by Heterotrophic Enrichment Cultures

    OpenAIRE

    Fliermans, C. B.; Phelps, T. J.; Ringelberg, D.; Mikell, A. T.; White, D. C.

    1988-01-01

    Microbial consortia capable of aerobically degrading more than 99% of exogenous trichloroethylene (TCE) (50 mg/liter) were collected from TCE-contaminated subsurface sediments and grown in enrichment cultures. TCE at concentrations greater than 300 mg/liter was not degraded, nor was TCE used by the consortia as a sole energy source. Energy sources which permitted growth included tryptone-yeast extract, methanol, methane, and propane. The optimum temperature range for growth and subsequent TCE...

  6. 21 CFR 866.2330 - Enriched culture medium.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Enriched culture medium. 866.2330 Section 866.2330...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2330 Enriched culture medium. (a) Identification. An enriched culture medium is a device that consists primarily of liquid...

  7. Extracellular enzyme activity in anaerobic bacterial cultures: evidence of pullulanase activity among mesophilic marine bacteria.

    OpenAIRE

    C. Arnosti; Repeta, D. J.

    1994-01-01

    The extracellular enzymatic activity of a mixed culture of anaerobic marine bacteria enriched on pullulan [alpha(1,6)-linked maltotriose units] was directly assessed with a combination of gel permeation chromatography (GPC) and nuclear magnetic resonance spectroscopy (NMR). Hydrolysis products of pullulan were separated by GPC into three fractions with molecular weights of > or = 10,000, approximately 5,000, and < or = 1,200. NMR spectra of these fractions demonstrated that pullulan was rapid...

  8. Characteristics of enriched cultures for bio-huff-`n`-puff tests at Jilin oil field

    Energy Technology Data Exchange (ETDEWEB)

    Xiu-Yuan Wang; Gang Dai; Yan-Fen Xue; Shu-Hua Xie [Institute of Microbiology, Beijing (China)] [and others

    1995-12-31

    Three enriched cultures (48, 15a, and 26a), selected from more than 80 soil and water samples, could grow anaerobically in the presence of crude oil at 30{degrees}C and could ferment molasses to gases and organic acids. Oil recovery by culture 48 in the laboratory model experiment was enhanced by 25.2% over the original reserves and by 53.7% over the residual reserves. Enriched culture 48 was composed of at least 4 species belonging to the genera Eubacterium, Fusobacterium, and Bacteroides. This enriched culture was used as inoculum for MEOR field trials at Jilin oil field with satisfactory results. The importance of the role of these isolates in EOR was confirmed by their presence and behavior in the fluids produced from the microbiologically treated reservoir.

  9. Enrichment and hydrogen production by marine anaerobic hydrogen-producing microflora

    Institute of Scientific and Technical Information of China (English)

    CAI JinLing; WANG GuangCe; LI YanChuan; ZHU DaLing; PAN GuangHua

    2009-01-01

    Acid,alkali,heat-shock,KNO3 and control pretreatment methods applied to anaerobic sludge were evaluated for their ability to selectively enrich the marine hydrogen-producing mixed microflora.Seawater culture medium was used as the substrate.The hydrogen yield of pretreated microflora was higher than that of the un-pretreated control (P<0.05).Among the pretreatment methods studied,heat-shock pretreatment yielded the greatest hydrogen production,which was 14.6 times that of the control.When the effect of initial pH on hydrogen production of heat-shock pretreated samples was studied,hydrogen was produced over the entire pH range (pH 4-10).The hydrogen yield peaked at initial pH 8 (79 mL/g sucrose) and then steadily decreased as the initial pH increased.Sucrose consumption was high at neutral initial pH.During the process of hydrogen production,pH decreased gradually,which indicated that the acquired microflora consisted of acidogenic bacteria.

  10. Microbial community in anaerobic hydrogen-producing microflora enriched from sludge compost.

    Science.gov (United States)

    Ueno, Y; Haruta, S; Ishii, M; Igarashi, Y

    2001-11-01

    Hydrogen production by thermophilic anaerobic microflora enriched from sludge compost was studied by using an artificial medium containing cellulose powder. Hydrogen gas was evolved with the formation of acetate, ethanol, and butyrate by decomposition of the cellulose powder. The hydrogen production yield was 2.0 mol/mol-hexose by either batch or chemostat cultivation. A medium that did not contain peptone demonstrated a lower hydrogen production yield of 1.0 mol/mol-hexose with less formation of butyrate. The microbial community in the microflora was investigated through isolation of the microorganisms by both plating and denaturing gradient gel electrophoresis (DGGE) of the' PCR-amplified V3 region of 16S rDNA. Sixty-eight microorganisms were isolated from the microflora and classified into nine distinct groups by genetic fingerprinting of the PCR-DGGE or by a random amplified polymorphic DNA analysis and determination of the partial sequence of 16S rDNA. Most of the isolates belonged to the cluster of the thermophilic Clostridium/Bacillus subphylum of low G+C gram-positive bacteria. Product formation by most of the isolated strains corresponded to that produced by the microflora. Thermoanaerobacterium thermosaccharolyticium was isolated in the enrichment culture with or without added peptone. and was detected with strong intensity by PCR-DGGE. Two other thermophilic cellulolytic microorganisms, Clostridium thermocellum and Clostridium cellulosi, were also detected by PCR-DGGE, although they could not be isolated. These findings imply that hydrogen production from cellulose by microflora is performed by a consortium of several species of microorganisms.

  11. Bacterial stress enrichment enhances anaerobic hydrogen production in cattle manure sludge.

    Science.gov (United States)

    Cheong, Dae-Yeol; Hansen, Conly L

    2006-10-01

    Methodology was evaluated to selectively enrich hydrogen-producing species present in biological sludge produced during organic wastewater treatment. The influence of bacterial stress enrichment on anaerobic hydrogen-producing microorganisms was investigated in batch tests using serum bottles. Enrichment conditions investigated included application of acute physical and chemical stresses: wet heat, dry heat and desiccation, use of a methanogen inhibitor, freezing and thawing, and chemical acidification with and without preacidification of the sludge at pH 3. For each enrichment sample, cultivation pH value was set at an initial value of 7. After application of selective enrichment (by bacterial stress), hydrogen production was significantly higher than that of untreated original sludge. Hydrogen production from the inocula with bacterial stress enrichment was 1.9-9.8 times greater when compared with control sludge. Chemical acidification using perchloric acid showed the best hydrogen production potential, irrespective of preacidification. Enhancement is due to the selective capture of hydrogen-producing sporeformers, which induces altered anaerobic fermentative metabolism. PMID:16525779

  12. Enrichment of denitrifying methanotrophic bacteria for application after direct low-temperature anaerobic sewage treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kampman, Christel, E-mail: christel.kampman@wur.nl [Sub-department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA, Wageningen (Netherlands); Hendrickx, Tim L.G. [Sub-department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA, Wageningen (Netherlands); Luesken, Francisca A.; Alen, Theo A. van; Op den Camp, Huub J.M.; Jetten, Mike S.M. [Department of Microbiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen (Netherlands); Zeeman, Grietje; Buisman, Cees J.N.; Temmink, Hardy [Sub-department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA, Wageningen (Netherlands)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer A new concept for low-temperature anaerobic sewage treatment is proposed. Black-Right-Pointing-Pointer In this concept, denitrification and methane oxidation are performed by Methylomirabilis oxyfera. Black-Right-Pointing-Pointer The bacteria were enriched from fresh water sediment using sequencing fed-batch reactors. Black-Right-Pointing-Pointer The volumetric consumption rate has to be increased by an order of magnitude for practical application. Black-Right-Pointing-Pointer Further research should focus on systems with improved biomass retention. - Abstract: Despite many advantages of anaerobic sewage treatment over conventional activated sludge treatment, it has not yet been applied in temperate zones. This is especially because effluent from low-temperature anaerobic treatment contains nitrogen and dissolved methane. The presence of nitrogen and methane offers the opportunity to develop a reactor in which methane is used as electron donor for denitrification. Such a reactor could be used in a new concept for low-temperature anaerobic sewage treatment, consisting of a UASB-digester system, a reactor for denitrification coupled to anaerobic methane oxidation, and a nitritation reactor. In the present study denitrifying methanotrophic bacteria similar to 'Candidatus Methylomirabilis oxyfera' were enriched. Maximum volumetric nitrite consumption rates were 33.5 mg NO{sub 2}{sup -}-N/L d (using synthetic medium) and 37.8 mg NO{sub 2}{sup -}-N/L d (using medium containing effluent from a sewage treatment plant), which are similar to the maximum rate reported so far. Though the goal was to increase the rates, in both reactors, after reaching these maximum rates, volumetric nitrite consumption rates decreased in time. Results indicate biomass washout may have significantly decelerated enrichment. Therefore, to obtain higher volumetric consumption rates, further research should focus on systems with complete biomass

  13. Enrichment of denitrifying methanotrophic bacteria for application after direct low-temperature anaerobic sewage treatment

    International Nuclear Information System (INIS)

    Highlights: ► A new concept for low-temperature anaerobic sewage treatment is proposed. ► In this concept, denitrification and methane oxidation are performed by Methylomirabilis oxyfera. ► The bacteria were enriched from fresh water sediment using sequencing fed-batch reactors. ► The volumetric consumption rate has to be increased by an order of magnitude for practical application. ► Further research should focus on systems with improved biomass retention. - Abstract: Despite many advantages of anaerobic sewage treatment over conventional activated sludge treatment, it has not yet been applied in temperate zones. This is especially because effluent from low-temperature anaerobic treatment contains nitrogen and dissolved methane. The presence of nitrogen and methane offers the opportunity to develop a reactor in which methane is used as electron donor for denitrification. Such a reactor could be used in a new concept for low-temperature anaerobic sewage treatment, consisting of a UASB-digester system, a reactor for denitrification coupled to anaerobic methane oxidation, and a nitritation reactor. In the present study denitrifying methanotrophic bacteria similar to ‘Candidatus Methylomirabilis oxyfera’ were enriched. Maximum volumetric nitrite consumption rates were 33.5 mg NO2−-N/L d (using synthetic medium) and 37.8 mg NO2−-N/L d (using medium containing effluent from a sewage treatment plant), which are similar to the maximum rate reported so far. Though the goal was to increase the rates, in both reactors, after reaching these maximum rates, volumetric nitrite consumption rates decreased in time. Results indicate biomass washout may have significantly decelerated enrichment. Therefore, to obtain higher volumetric consumption rates, further research should focus on systems with complete biomass retention.

  14. Effect of methanogenic substrates on anaerobic oxidation of methane and sulfate reduction by an anaerobic methanotrophic enrichment.

    KAUST Repository

    Meulepas, Roel J W

    2010-05-06

    Anaerobic oxidation of methane (AOM) coupled to sulfate reduction (SR) is assumed to be a syntrophic process, in which methanotrophic archaea produce an interspecies electron carrier (IEC), which is subsequently utilized by sulfate-reducing bacteria. In this paper, six methanogenic substrates are tested as candidate-IECs by assessing their effect on AOM and SR by an anaerobic methanotrophic enrichment. The presence of acetate, formate or hydrogen enhanced SR, but did not inhibit AOM, nor did these substrates trigger methanogenesis. Carbon monoxide also enhanced SR but slightly inhibited AOM. Methanol did not enhance SR nor did it inhibit AOM, and methanethiol inhibited both SR and AOM completely. Subsequently, it was calculated at which candidate-IEC concentrations no more Gibbs free energy can be conserved from their production from methane at the applied conditions. These concentrations were at least 1,000 times lower can the final candidate-IEC concentration in the bulk liquid. Therefore, the tested candidate-IECs could not have been produced from methane during the incubations. Hence, acetate, formate, methanol, carbon monoxide, and hydrogen can be excluded as sole IEC in AOM coupled to SR. Methanethiol did inhibit AOM and can therefore not be excluded as IEC by this study.

  15. Effect of inorganic carbon on anaerobic ammonium oxidation enriched in sequencing batch reactor

    Institute of Scientific and Technical Information of China (English)

    Liao Dexiang; Li Xiaoming; Yang Qi; Zeng Guangming; Guo Liang; Yue Xiu

    2008-01-01

    The present lab-scale research reveals the enrichment of anaerobic ammonium oxidation microorganism from methanogenic anaerobic granular sludge and the effect of inorganic carbon (sodium bicarbonate) on anaerobic ammonium oxidation. The enrichment of anammox bacteria was carried out in a 7.0-L SBR and the effect of bicarbonate on anammox was conducted in a 3.0-L SBR. Research results , especially the biomass, showed first signs of anammox activity after 54 d cultivation with synthetic wastewater, when the pH was controlled between 7.5 and 8.3, the temperature was 35℃. The anammox activity increased as the influent bicarbonate concentration increased from 1.0 to 1.5 g/L and then, was inhibited as the bicarbonate concentration approached 2.0 g/L. However, the activity could be restored by the reduction of bicarbonate concentration to 1.0 g/L, as shown by rapid conversion of ammonium, and nitrite and nitrate production with normal stoichiometry. The optimization of the bicarbonate concentration in the reactor could increase the anammox rate up to 66.4 mgN/(L·d).

  16. Enhancement of anaerobic methanogenesis at a short hydraulic retention time via bioelectrochemical enrichment of hydrogenotrophic methanogens.

    Science.gov (United States)

    Li, Yang; Zhang, Yaobin; Liu, Yiwen; Zhao, Zhiqiang; Zhao, Zisheng; Liu, Sitong; Zhao, Huimin; Quan, Xie

    2016-10-01

    Anaerobic digestion (AD) is an important energy strategy for converting organic waste to CH4. A major factor limiting the practical applicability of AD is the relatively long hydraulic retention time (HRT) which declines the treatment efficiency of digesters. A coupling process of anaerobic digestion and 'electromethanogenesis' was proposed to enhance anaerobic digestion at a short HRT in this study. Microorganisms analysis indicated that the electric-biological reactor enriched hydrogenotrophic methanogens in both cathodic biofilm and suspended sludge, helping achieve the high organic removal (71.0% vs 42.3% [control reactor]) and CH4 production (248.5mL/h vs 51.3mL/h), while the additional electric input was only accounted for 25.6% of the energy income from the increased CH4 production. This study demonstrated that a bioelectrochemical enhanced anaerobic reactor could improve the CH4 production and organic removal at a short HRT, providing an economically feasible scheme to treat wastewater. PMID:27394997

  17. Enhancement of anaerobic methanogenesis at a short hydraulic retention time via bioelectrochemical enrichment of hydrogenotrophic methanogens.

    Science.gov (United States)

    Li, Yang; Zhang, Yaobin; Liu, Yiwen; Zhao, Zhiqiang; Zhao, Zisheng; Liu, Sitong; Zhao, Huimin; Quan, Xie

    2016-10-01

    Anaerobic digestion (AD) is an important energy strategy for converting organic waste to CH4. A major factor limiting the practical applicability of AD is the relatively long hydraulic retention time (HRT) which declines the treatment efficiency of digesters. A coupling process of anaerobic digestion and 'electromethanogenesis' was proposed to enhance anaerobic digestion at a short HRT in this study. Microorganisms analysis indicated that the electric-biological reactor enriched hydrogenotrophic methanogens in both cathodic biofilm and suspended sludge, helping achieve the high organic removal (71.0% vs 42.3% [control reactor]) and CH4 production (248.5mL/h vs 51.3mL/h), while the additional electric input was only accounted for 25.6% of the energy income from the increased CH4 production. This study demonstrated that a bioelectrochemical enhanced anaerobic reactor could improve the CH4 production and organic removal at a short HRT, providing an economically feasible scheme to treat wastewater.

  18. Nitrogen removal by autotrophic ammonium oxidizing bacteria enrichment under anaerobic conditions

    Directory of Open Access Journals (Sweden)

    Pongsak (Lek Noophan

    2008-07-01

    Full Text Available Sludge from an anoxic tank at the centralized wastewater treatment plant, Nong Khaem, Bangkok, Thailand, was inoculatedin an anaerobic sequencing batch reactor (ASBR. The optimal compositions and operating conditions of the stock of autotrophic ammonium oxidizing bacteria medium were determined. The process of oxidizing ammonium with bacteria under anaerobic conditions is often referred to as the Anammox process (NO2- to N2 gas, using NH4+ as the electron donor and NO2- as the electron acceptor. The startup period for the anammox culture took more than three months. With ammoniumand nitrite concentration ratios of 1:1.38 and 1:1.6, the nitrogen conversion rate zero order. Fluorescent in situ hybridization(FISH was used to identify specific autotrophic ammonium oxidizing bacteria (Nitrosomonas spp., Candidatus Brocadia anammoxidans, and Candidatus Kuenenia stuttgartiensis. Results from this work demonstrated a shift in the species of ammonium oxidizing bacteria from Nitrosomonas spp. to Candidati Brocadia anammoxidans and Kuenenia stuttgartiensis, with increased ammonium concentrations from 3 mM to 15 mM. Under NH4+:NO2- ratios of 1:1.38 and 1:1.6 the ammoniumoxidizing bacteria were able to remove both ammonium and nitrite simultaneously. The specific nitrogen removal rate of theanammox bacteria (Candidati Brocadia anammoxidans and Kuenenia stuttgartiensis was significantly higher than that of anaerobic ammonium oxidizing bacteria (Nitrosomonas spp.. Anaerobic ammonium oxidizing bacteria (Candidati Brocadia anammoxidans and Kuenenia stuttgartiensis are strict anaerobes.

  19. Anaerobic Cultures from Preserved Tissues of Baby Mammoth

    Science.gov (United States)

    Pikuta, Elena V.; Hoover, Richard B.; Fisher, Daniel

    2011-01-01

    Microbiological analysis of several cold-preserved tissue samples from the Siberian baby mammoth known as Lyuba revealed a number of culturable bacterial strains that were grown on anaerobic media at 4 C. Lactic acid produced by LAB (lactic acid bacteria) group, usually by members of the genera Carnobacterium and Lactosphera, appears to be a wonderful preservative that prevents other bacteria from over-dominating a system. Permafrost and lactic acid preserved the body of this one-month old baby mammoth and kept it in exceptionally good condition, resulting in this mammoth being the most complete such specimen ever recovered. The diversity of novel anaerobic isolates was expressed on morphological, physiological and phylogenetic levels. Here we discuss the specifics of the isolation of new strains, differentiation from trivial contamination, and preliminary results for the characterization of cultures.

  20. Anaerobic cultures from preserved tissues of baby mammoth

    Science.gov (United States)

    Pikuta, Elena V.; Fisher, Daniel; Hoover, Richard B.

    2011-10-01

    Microbiological analysis of several cold-preserved tissue samples from the Siberian baby mammoth known as Lyuba revealed a number of culturable bacterial strains that were grown on anaerobic media at 3 oC. Lactic acid produced by LAB (lactic acid bacteria) group, usually by members of the genera Carnobacterium and Lactosphera, appears to be a wonderful preservative that keeps other bacteria from colonizing a system. Permafrost and lactic acid preserved the body of this one month-old baby mammoth and kept it in exceptionally good condition, resulting in this mammoth being the most complete sample of the species ever recovered. The diversity of novel psychrophilic anaerobic isolates was expressed on morphological, physiological and phylogenetic levels. Here, we discuss the specifics of the isolation of new psychrophilic strains, differentiation from trivial contamination, and preliminary results for characterization of the cultures.

  1. Enrichment of denitrifying methane-oxidizing microorganisms using up-flow continuous reactors and batch cultures.

    Directory of Open Access Journals (Sweden)

    Masashi Hatamoto

    Full Text Available Denitrifying anaerobic methane oxidizing (DAMO microorganisms were enriched from paddy field soils using continuous-flow and batch cultures fed with nitrate or nitrite as a sole electron acceptor. After several months of cultivation, the continuous-flow cultures using nitrite showed remarkable simultaneous methane oxidation and nitrite reduction and DAMO bacteria belonging to phylum NC10 were enriched. A maximum volumetric nitrite consumption rate of 70.4±3.4 mg-N·L(-1·day(-1 was achieved with very short hydraulic retention time of 2.1 hour. In the culture, about 68% of total microbial cells were bacteria and no archaeal cells were detected by fluorescence in situ hybridization. In the nitrate-fed continuous-flow cultures, 58% of total microbial cells were bacteria while archaeal cells accounted for 7% of total cell numbers. Phylogenetic analysis of pmoA gene sequence showed that enriched DAMO bacteria in the continuous-flow cultivation had over 98% sequence similarity to DAMO bacteria in the inoculum. In contrast, for batch culture, the enriched pmoA gene sequences had 89-91% sequence similarity to DAMO bacteria in the inoculum. These results indicate that electron acceptor and cultivation method strongly affect the microbial community structures of DAMO consortia.

  2. Continuous enrichment culture and molecular monitoring to investigate the microbial diversity of thermophiles inhabiting deep-sea hydrothermal ecosystems

    OpenAIRE

    POSTEC, Anne; Urios, Laurent; Lesongeur, Francoise; Ollivier, Bernard; Querellou, Joel; Godfroy, Anne

    2005-01-01

    The microflora developing during a continuous enrichment culture from a hydrothermal chimney sample was investigated by molecular methods. The culture was performed in a gas-lift bioreactor under anaerobic conditions, at 90 degrees C and pH 6.5, on a complex medium containing sulfur as the terminal electron acceptor. Archaeal and bacterial diversity was studied. Microorganisms affiliated with the genera Pyrococcus, Marinitoga, and Bacillus were detected through DGGE analysis of 16S rDNA. Addi...

  3. Diversity of benzyl- and alkylsuccinate synthase genes in hydrocarbon-impacted environments and enrichment cultures.

    Science.gov (United States)

    Callaghan, Amy V; Davidova, Irene A; Savage-Ashlock, Kristen; Parisi, Victoria A; Gieg, Lisa M; Suflita, Joseph M; Kukor, Jerome J; Wawrik, Boris

    2010-10-01

    Hydrocarbon-degrading microorganisms play an important role in the natural attenuation of spilled petroleum in a variety of anoxic environments. The role of benzylsuccinate synthase (BSS) in aromatic hydrocarbon degradation and its use as a biomarker for field investigations are well documented. The recent discovery of alkylsuccinate synthase (ASS) allows the opportunity to test whether its encoding gene, assA, can serve as a comparable biomarker of anaerobic alkane degradation. Degenerate assA- and bssA-targeted PCR primers were designed in order to survey the diversity of genes associated with aromatic and aliphatic hydrocarbon biodegradation in petroleum-impacted environments and enrichment cultures. DNA was extracted from an anaerobic alkane-degrading isolate (Desulfoglaeba alkenexedens ALDC), hydrocarbon-contaminated river and aquifer sediments, a paraffin-degrading enrichment, and a propane-utilizing mixed culture. Partial assA and bssA genes were PCR amplified, cloned, and sequenced, yielding several novel clades of assA genes. These data expand the range of alkane-degrading conditions for which relevant gene sequences are available and indicate that considerable diversity of assA genes can be found in hydrocarbon-impacted environments. The detection of genes associated with anaerobic alkane degradation in conjunction with the in situ detection of alkylsuccinate metabolites was also demonstrated. Comparable molecular signals of assA/bssA were not found when environmental metagenome databases of uncontaminated sites were searched. These data confirm that the assA gene is a useful biomarker for anaerobic alkane metabolism. PMID:20504044

  4. Simultaneous hydrogen production and consumption in Anaerobic mixed culture fermentation

    OpenAIRE

    Carlos Dinamarca, Rune Bakke

    2012-01-01

    The aim of the present study is to investigate the relevance of homoacetogenic H2 consumption on the bio-hydrogen yield and products distribution in mixed culture fermentation. A hybrid anaerobic reactor was operated for 93 days with variable pH and organic loads between 8-16 g glucose/L.d for this purpose. High initial H2 yield decreased gradually to an equivalent of 0.02-0.4 mol H2/mol glucose consumed. The distribution of the dissolved organic products was influenced strongly by reactor pH...

  5. Selective enrichment of Geobacter sulfurreducens from anaerobic granular sludge with quinones as terminal electron acceptors

    NARCIS (Netherlands)

    Cervantes-Carillo, F.J.; Duong Dac, T.; Ivanova, A.E.; Roest, de K.; Akkermans, A.D.L.; Lettinga, G.; Field, J.A.

    2003-01-01

    A quinone-respiring, enrichment culture derived from methanogenic granular sludge was phylogenetically characterized by using a combined cloning-denaturing gradient gel electrophoresis (DGGE) method, which revealed that the consortium developed was dominated by a single microorganism: 97% related, i

  6. Diversity of reductive dehalogenase genes from environmental samples and enrichment cultures identified with degenerate primer PCR screens

    OpenAIRE

    LauraAudreyHug; ElizabethAnneEdwards

    2013-01-01

    Reductive dehalogenases are the critical enzymes for anaerobic organohalide respiration, a microbial metabolic process that has been harnessed for bioremediation efforts to resolve chlorinated solvent contamination in groundwater and is implicated in the global halogen cycle. Reductive dehalogenase sequence diversity is informative for the dechlorination potential of the site or enrichment culture. A suite of degenerate PCR primers targeting a comprehensive curated set of reductive dehaloge...

  7. Retention and transport of an anaerobic trichloroethene dechlorinating microbial culture in anaerobic porous media.

    Science.gov (United States)

    Zhang, Huixin; Ulrich, Ania C; Liu, Yang

    2015-06-01

    The influence of solution chemistry on microbial transport was examined using the strictly anaerobic trichloroethene (TCE) bioaugmentation culture KB-1(®). A column was employed to determine transport behaviors and deposition kinetics of three distinct functional species in KB-1(®), Dehalococcoides, Geobacter, and Methanomethylovorans, over a range of ionic strengths under a well-controlled anaerobic condition. A quantitative polymerase chain reaction (qPCR) was utilized to enumerate cell concentration and complementary techniques were implemented to evaluate cell surface electrokinetic potentials. Solution chemistry was found to positively affect the deposition rates, which was consistent with calculated Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energies. Retained microbial profiles showed spatially constant colloid deposition rate coefficients, in agreement with classical colloid filtration theory (CFT). It was interesting to note that the three KB-1(®) species displayed similar transport and retention behaviors under the defined experimental conditions despite their different cell electrokinetic properties. A deeper analysis of cell characteristics showed that factors, such as cell size and shape, concentration, and motility were involved in determining adhesion behavior. PMID:25935560

  8. Enrichment and characterization of an anaerobic cellulolytic microbial consortium SQD-1.1 from mangrove soil.

    Science.gov (United States)

    Gao, Zhao-Ming; Xu, Xun; Ruan, Ling-Wei

    2014-01-01

    Enrichment of microbial consortia provides an approach to simulate and investigate microbial communities in natural environments. In this study, a cellulolytic microbial consortium SQD-1.1 was enriched from mangrove soil of Qinglan port (Hainan, China) by 27 times continuous subcultivation under anaerobic static conditions. The consortium could completely degrade 0.2% (w/v) filter paper within 3 days and utilized it as the sole carbon source. PCR-denaturing gradient gel electrophoresis analysis revealed a stable microbial community structure in the incubation process of 10 days and in the procedure of subcultivation. Twenty-four operational taxonomic units belonging to seven phyla were obtained from the full-length 16S rRNA gene library. Five clones, closest related to the genera Alkaliflexus, Clostridium, Alistipes, Spirochaeta, and Trichococcus, were the predominant ones. Among them, M117, phylogeneticly showing high similarity (16S rRNA gene identity, 95.3%) with the cellulolytic anaerobic bacterium Clostridium straminisolvens CSK1(T), was the potential key cellulolytic bacterium. Using the plate cultivation method, 12 strains, including one potential new species and four potential new species of new genera, were isolated. The strain P2, corresponding to the most frequently detected clone (M05) in the 16S rRNA gene library, showed both CMCase and xylanase activity and may be another important cellulolytic bacterium. The findings of cellulase activity in cell pellet and cohesion and dockerin domains in metagenome data further suggested the potential of utilization of cellulosomes by the consortium to degrade cellulose. Consortium SQD-1.1 provides a candidate for investigating the mechanism of cellulose degradation under anoxic conditions in natural environments. PMID:23529681

  9. The maximum specific hydrogen-producing activity of anaerobic mixed cultures: definition and determination

    Science.gov (United States)

    Mu, Yang; Yang, Hou-Yun; Wang, Ya-Zhou; He, Chuan-Shu; Zhao, Quan-Bao; Wang, Yi; Yu, Han-Qing

    2014-06-01

    Fermentative hydrogen production from wastes has many advantages compared to various chemical methods. Methodology for characterizing the hydrogen-producing activity of anaerobic mixed cultures is essential for monitoring reactor operation in fermentative hydrogen production, however there is lack of such kind of standardized methodologies. In the present study, a new index, i.e., the maximum specific hydrogen-producing activity (SHAm) of anaerobic mixed cultures, was proposed, and consequently a reliable and simple method, named SHAm test, was developed to determine it. Furthermore, the influences of various parameters on the SHAm value determination of anaerobic mixed cultures were evaluated. Additionally, this SHAm assay was tested for different types of substrates and bacterial inocula. Our results demonstrate that this novel SHAm assay was a rapid, accurate and simple methodology for determining the hydrogen-producing activity of anaerobic mixed cultures. Thus, application of this approach is beneficial to establishing a stable anaerobic hydrogen-producing system.

  10. Methane enrichment digestion experiments at the anaerobic experimental test unit at Walt Disney World. Final report, March 1989-August 1990

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, V.J.; Hill, A.H.

    1993-06-01

    The goal of the project was to determine the technical feasibility of utilizing a novel concept in anaerobic digestion, in-situ methane enrichment digestion or MED for producing utility-grade gas from a pilot-scale anaerobic digester. MED tests conducted during this program consistently achieved digester product gas with a methane (CH4) content of greater than 90% (on a dry-, nitrogen-free basis). The MED concept, because it requires relatively simple equipment and modest energy input, has the potential to simplify gas cleanup requirements and substantially reduce the cost of converting wastes and biomass to pipeline quality gas.

  11. Anaerobic incubation of membrane filter cultures for improved detection of fecal coliforms from recreational waters.

    OpenAIRE

    Doyle, J D; Tunnicliff, B; Brickler, S K; Kramer, R E; Sinclair, N. A.

    1984-01-01

    Anaerobic incubation of membrane filter cultures significantly enhanced detection of fecal coliforms in surface-water samples from recreational beaches. In contrast to standard aerobic incubation, anaerobic incubation suppressed overgrowth of masking, noncoliform bacteria but did not increase the frequency of fecal coliform recovery.

  12. Carbon capture and biogas enhancement by carbon dioxide enrichment of anaerobic digesters treating sewage sludge or food waste

    OpenAIRE

    Bajón, Fernández Y; Soares, Ana; Villa, Raffaella; Vale, P; Cartmell, Elise

    2014-01-01

    The increasing concentration of carbon dioxide (CO2) in the atmosphere and the stringent greenhouse gases (GHG) reduction targets, require the development of CO2 sequestration technologies applicable for the waste and wastewater sector. This study addressed the reduction of CO2 emissions and enhancement of biogas production associated with CO2 enrichment of anaerobic digesters (ADs). The benefits of CO2 enrichment were examined by injecting CO2 at 0, 0.3, 0.6 and 0.9M fractions into batch ADs...

  13. Simultaneous hydrogen production and consumption in Anaerobic mixed culture fermentation

    Directory of Open Access Journals (Sweden)

    Carlos Dinamarca, Rune Bakke

    2012-01-01

    Full Text Available The aim of the present study is to investigate the relevance of homoacetogenic H2 consumption on the bio-hydrogen yield and products distribution in mixed culture fermentation. A hybrid anaerobic reactor was operated for 93 days with variable pH and organic loads between 8-16 g glucose/L.d for this purpose. High initial H2 yield decreased gradually to an equivalent of 0.02-0.4 mol H2/mol glucose consumed. The distribution of the dissolved organic products was influenced strongly by reactor pH, while the overall H2 yield was not. Low H2 yield is attributed mainly to homoacetogenesis at pH greater than 4.6 and to reduced products formation at pH less than 4.6. Simultaneous hydrogen production and consumption occurred and at least 22 % of the produced molecular hydrogen, mainly from butyrate fermentation, was used for the reduction of CO2 to acetate.

  14. Enrichment of denitrifying methanotrophic bacteria for application after direct low-temperature anaerobic sewage treatment

    NARCIS (Netherlands)

    Kampman, C.; Hendrickx, T.L.G.; Luesken, F.; Alen, T.A.; Jetten, M.S.M.; Camp, op den H.J.M.; Zeeman, G.; Buisman, C.J.N.; Temmink, B.G.

    2012-01-01

    Despite many advantages of anaerobic sewage treatment over conventional activated sludge treatment, it has not yet been applied in temperate zones. This is especially because effluent from low-temperature anaerobic treatment contains nitrogen and dissolved methane. The presence of nitrogen and metha

  15. Enrichment of Methanosaetaceae on carbon felt and biochar during anaerobic digestion of a potassium-rich molasses stream.

    Science.gov (United States)

    De Vrieze, Jo; Devooght, Arno; Walraedt, Diego; Boon, Nico

    2016-06-01

    Biorefineries allow the production of value-added chemicals, yet this also causes the formation of considerable amounts of wastewater that require suitable treatment. These biorefinery wastewaters often contain a high salinity, which inhibits methanogenesis. In this research, molasses were used to mimic these waste streams to evaluate their treatability by anaerobic digestion. Two different carrier materials, i.e., carbon felt and biochar, with similar surface properties were evaluated for their potential to stabilize anaerobic digestion of these wastewaters via active enrichment of the methanogenic community. Initial stable methane production values between 620 and 640 mL CH4 L(-1) day(-1) were reported in each treatment. At the end of the experiment, methane production decreased with more than 50 %, while VFA increased to values up to 20 g COD L(-1), indicating severe process failure, due to the high potassium concentration in these wastewaters, irrespective of the presence of carrier material. However, an increased relative abundance of Methanosaetaceae both on the biochar and carbon felt was observed. In conclusion, this research demonstrated that carbon felt and biochar are both suitable carrier materials for selective enrichment of Methanosaetaceae, yet this did not lead to stable anaerobic digestion of a potassium-rich molasses waste stream. The increased relative abundance of Methanosaetaceae on both carrier materials can, nonetheless, be considered valuable in terms of alternative applications and warrants further research. PMID:27063010

  16. Batch fermentative hydrogen production by enriched mixed culture: Combination strategy and their microbial composition.

    Science.gov (United States)

    Sivagurunathan, Periyasamy; Sen, Biswarup; Lin, Chiu-Yue

    2014-02-01

    The effect of individual and combined mixed culture on dark fermentative hydrogen production performance was investigated. Mixed cultures from cow dung (C1), sewage sludge (C2), and pig slurry (C3) were enriched under strict anaerobic conditions at 37°C with glucose as the sole carbon source. Biochemical hydrogen production test in peptone-yeast-glucose (PYG) and basal medium was performed for individual mixed cultures (C1, C2 and C3) and their combinations (C1-C2, C2-C3, C1-C3 and C1-C2-C3) at a glucose concentration of 10 g/L, 37°C and initial pH 7. Maximum hydrogen yields (HY) of 2.0 and 1.86 [Formula: see text] by C2, and 1.98 and 1.95 mol(H2)/mol(glucose) by C2-C3 were obtained in PYG and basal medium, respectively. Butyrate and acetate were the major soluble metabolites produced by all the cultures, and the ratio of butyrate to acetate was ∼2 fold higher in basal medium than PYG medium, indicating strong influence of media formulation on glucose catabolism. The major hydrogen-producing bacterial strains, observed in all mixed cultures, belonged to Clostridium butyricum, C. saccharobutylicum, C. tertium and C. perfringens. The hydrogen production performance of the combined mixed culture (C2-C3) was further evaluated on beverage wastewater (10 g/L) at pH 7 and 37°C. The results showed an HY of 1.92 mol(H2)/mol(glucose-equivalent). Experimental evidence suggests that hydrogen fermentation by mixed culture combination could be a novel strategy to improve the HY from industrial wastewater. PMID:24095211

  17. Batch fermentative hydrogen production by enriched mixed culture: Combination strategy and their microbial composition.

    Science.gov (United States)

    Sivagurunathan, Periyasamy; Sen, Biswarup; Lin, Chiu-Yue

    2014-02-01

    The effect of individual and combined mixed culture on dark fermentative hydrogen production performance was investigated. Mixed cultures from cow dung (C1), sewage sludge (C2), and pig slurry (C3) were enriched under strict anaerobic conditions at 37°C with glucose as the sole carbon source. Biochemical hydrogen production test in peptone-yeast-glucose (PYG) and basal medium was performed for individual mixed cultures (C1, C2 and C3) and their combinations (C1-C2, C2-C3, C1-C3 and C1-C2-C3) at a glucose concentration of 10 g/L, 37°C and initial pH 7. Maximum hydrogen yields (HY) of 2.0 and 1.86 [Formula: see text] by C2, and 1.98 and 1.95 mol(H2)/mol(glucose) by C2-C3 were obtained in PYG and basal medium, respectively. Butyrate and acetate were the major soluble metabolites produced by all the cultures, and the ratio of butyrate to acetate was ∼2 fold higher in basal medium than PYG medium, indicating strong influence of media formulation on glucose catabolism. The major hydrogen-producing bacterial strains, observed in all mixed cultures, belonged to Clostridium butyricum, C. saccharobutylicum, C. tertium and C. perfringens. The hydrogen production performance of the combined mixed culture (C2-C3) was further evaluated on beverage wastewater (10 g/L) at pH 7 and 37°C. The results showed an HY of 1.92 mol(H2)/mol(glucose-equivalent). Experimental evidence suggests that hydrogen fermentation by mixed culture combination could be a novel strategy to improve the HY from industrial wastewater.

  18. Large scale production of Blackleg vaccine by fermenter and enriched culture medium in Iran

    Directory of Open Access Journals (Sweden)

    Pilehchian Langroudi, R.

    2012-06-01

    Full Text Available In all biological systems growth is defined as increase of chemical compounds. Bacteria can achieve to balanced growth if they are growing in a medium, which are completely adapted to it. Clostridium chauvoei, (Clostridium feseri is an anaerobic, spore forming, motile, and polymorph bacteria, which its size varies from 0.5-1 to 3-8 micron and could be observed as individual bacterium, diplo, and rarely streptococcus. Blackleg is a fatal disease of young cattle. It produces an acute local infection, and the resulting blood poisoning leads to rapid death. Clostridium chauvoei and, less frequently, Clostridium septicum are the most commonly responsible organisms. Vaccination is the only effective means for controlling of blackleg disease. Several kinds of vaccine are available commercially. It is 4 decades that blackleg vaccine is produced in Razi institute and because of enhanced demand of country, decision was made to improve the production procedure of this vaccine using large-scale fermenter, so the aim of this study was adaptation of Clostridium chauvoei to growth and proliferation in fermenter for preparation of a potent vaccine. Accordingly attempts were made to prepare and formulate the ingredients in order to obtain high yield of Clostridium chauvoei in culture medium by fermenter. All experiments were done in two sets: A-growth in glass bottles using conventional culture medium and B-growth in fermenter using conventional culture medium similar to A and also enriched culture medium. Results showed high yield of Clostridium chauvoei suspension in fermenter after 10 hours, using enriched culture medium (more than 1,480,000,000 organisms/ml, but no significant changes was obtained in glass bottles conditions comparing to the fermenter conditions. The safety and potency of the prepared vaccine was determined in sheep and guinea pigs according to British pharmacopoeia (veterinary with satisfactory results. Since this research has been

  19. Diversity and enrichment of nitrite-dependent anaerobic methane oxidizing bacteria from wastewater sludge

    OpenAIRE

    Luesken, Francisca A.; van Alen, Theo A.; van der Biezen, Erwin; Frijters, Carla; Toonen, Ger; Kampman, Christel; Hendrickx, Tim L. G.; Zeeman, Grietje; Temmink, Hardy; Strous, Marc; Op den Camp, Huub J. M.; Jetten, Mike S. M.

    2011-01-01

    Recently discovered microorganisms affiliated to the bacterial phylum NC10, named “Candidatus Methylomirabilis oxyfera”, perform nitrite-dependent anaerobic methane oxidation. These microorganisms could be important players in a novel way of anaerobic wastewater treatment where ammonium and residual dissolved methane might be removed at the expense of nitrate or nitrite. To find suitable inocula for reactor startup, ten selected wastewater treatment plants (WWTPs) located in The Netherlands w...

  20. Enrichment of specific electro-active microorganisms and enhancement of methane production by adding granular activated carbon in anaerobic reactors.

    Science.gov (United States)

    Lee, Jung-Yeol; Lee, Sang-Hoon; Park, Hee-Deung

    2016-04-01

    Direct interspecies electron transfer (DIET) via conductive materials can provide significant benefits to anaerobic methane formation in terms of production amount and rate. Although granular activated carbon (GAC) demonstrated its applicability in facilitating DIET in methanogenesis, DIET in continuous flow anaerobic reactors has not been verified. Here, evidences of DIET via GAC were explored. The reactor supplemented with GAC showed 1.8-fold higher methane production rate than that without GAC (35.7 versus 20.1±7.1mL-CH4/d). Around 34% of methane formation was attributed to the biomass attached to GAC. Pyrosequencing of 16S rRNA gene demonstrated the enrichment of exoelectrogens (e.g. Geobacter) and hydrogenotrophic methanogens (e.g. Methanospirillum and Methanolinea) from the biomass attached to GAC. Furthermore, anodic and cathodic currents generation was observed in an electrochemical cell containing GAC biomass. Taken together, GAC supplementation created an environment for enriching the microorganisms involved in DIET, which increased the methane production rate. PMID:26836607

  1. Diversity of reductive dehalogenase genes from environmental samples and enrichment cultures identified with degenerate primer PCR screens.

    Directory of Open Access Journals (Sweden)

    Laura Audrey Hug

    2013-11-01

    Full Text Available Reductive dehalogenases are the critical enzymes for anaerobic organohalide respiration, a microbial metabolic process that has been harnessed for bioremediation efforts to resolve chlorinated solvent contamination in groundwater and is implicated in the global halogen cycle. Reductive dehalogenase sequence diversity is informative for the dechlorination potential of the site or enrichment culture. A suite of degenerate PCR primers targeting a comprehensive curated set of reductive dehalogenase genes was designed and applied to twelve DNA samples extracted from contaminated and pristine sites, as well as six enrichment cultures capable of reducing chlorinated compounds to non-toxic end-products. The amplified gene products from four environmental sites and two enrichment cultures were sequenced using Illumina HiSeq, and the reductive dehalogenase complement of each sample determined. The results indicate that the diversity of the reductive dehalogenase gene family is much deeper than is currently accounted for: one-third of the translated proteins have less than 70% pairwise amino acid identity to database sequences. Approximately 60% of the sequenced reductive dehalogenase genes were broadly distributed, being identified in four or more samples, and often in previously sequenced genomes as well. In contrast, 17% of the sequenced reductive dehalogenases were unique, present in only a single sample and bearing less than 90% pairwise amino acid identity to any previously identified proteins. Many of the broadly distributed reductive dehalogenases are uncharacterized in terms of their substrate specificity, making these intriguing targets for further biochemical experimentation. Finally, comparison of samples from a contaminated site and an enrichment culture derived from the same site eight years prior allowed examination of the effect of the enrichment process.

  2. Hydrogenase activity in aged, nonviable Desulfovibrio vulgaris cultures and its significance in anaerobic biocorrosion.

    Science.gov (United States)

    Chatelus, C; Carrier, P; Saignes, P; Libert, M F; Berlier, Y; Lespinat, P A; Fauque, G; Legall, J

    1987-07-01

    Batch cultures of Desulfovibrio vulgaris stored at 32 degrees C for 10 months have been found to retain 50% of the hydrogenase activity of a 1-day culture. The hydrogenase found in old cultures needs reducing conditions for its activation. Viable cell counts are negative after 6 months, showing that the hydrogenase activity does not depend on the presence of viable cells. These observations are of importance in the understanding of anaerobic biocorrosion of metals caused by depolarization phenomena.

  3. Fatty Acids Profile during Anaerobic Digestion of Night Soil-Effect of temperature, Calcium Carbonate and Selectively-enriched Inoculum

    Directory of Open Access Journals (Sweden)

    S. I. Alam

    1996-01-01

    Full Text Available Anaerobic biodegradation of night soil was carried out at 5-30 degree centigrade with 1.8-10.62 per cent volatile solids (VS. Biogas production increased with the temperature and VS up to 6.2 per cent. Further increase in VS caused higher Volatile fatty acids (VFA accumulation resulting in decreased gas production. Acetate and propionate accounted for 62-83 per cent of total VFA. Butyrate to isobutyrate ratio increased with VS. Calcium Carbonate promoted VS degradation, biogas production and VFA degradation. The increased methanogenic and decreased sulphate-reducing bacteria caused proportional changes in CH4 and H2S gases. Enrichment with H2 oxidising methanogenic consortium is beneficial by enhancing VFA utilisation by two to three fold.

  4. Laboratory survey and literature review of anaerobic bacteriology: foundations of a clinically orientated and evidence-based workup for anaerobic cultures.

    Science.gov (United States)

    Peeters, Bart; Magerman, Koen; Waumans, Luc; Cartuyvels, Reinoud

    2016-09-01

    Since the introduction of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) in routine microbiology laboratories, identification of anaerobic bacteria has become easier. These increased possibilities provide new challenges concerning analytical workup and reporting of anaerobes. In February 2015, an extensive web-based survey on pre-analytical, analytical and post-analytical procedures of anaerobic microbiology was sent to 53 Belgian, university and non-university hospital laboratories. Answers of 34 participating laboratories revealed a huge diversity in all analytical stages of anaerobic microbiology. Whether or not colony types were identified was mainly based on anatomical origin of the sample, colony morphology, and total number of different anaerobic isolates in the sample, while reporting of isolate results and performing anti-microbial susceptibility testing was mainly based on anatomical origin of the sample, number of different anaerobic isolates, and the identification of the anaerobic bacteria. These variety of workup procedures were mainly expert-based and have not been extensively clinically validated. For this reason, a standardized, clinically orientated, and feasible procedure for the workup of anaerobic cultures was developed, using MALDI-TOF MS identification, based upon literature data and existing guidelines. PMID:27344540

  5. Enrichment of a microbial community performing anaerobic oxidation of methane in a continuous high-pressure bioreactor

    Directory of Open Access Journals (Sweden)

    Wang Fengping

    2011-06-01

    Full Text Available Abstract Background Anaerobic oxidation of methane coupled to sulphate reduction (SR-AOM prevents more than 90% of the oceanic methane emission to the atmosphere. In a previous study, we demonstrated that the high methane pressure (1, 4.5, and 8 MPa stimulated in vitro SR-AOM activity. However, the information on the effect of high-pressure on the microbial community structure and architecture was still lacking. Results In this study we analysed the long-term enrichment (286 days of this microbial community, which was mediating SR-AOM in a continuous high-pressure bioreactor. 99.7% of the total biovolume represented cells in the form of small aggregates (diameter less then 15 μm. An increase of the total biovolume was observed (2.5 times. After 286 days, the ANME-2 (anaerobic methanotrophic archaea subgroup 2 and SRB (sulphate reducing bacteria increased with a factor 12.5 and 8.4, respectively. Conclusion This paper reports a net biomass growth of communities involved in SR-AOM, incubated at high-pressure.

  6. Carbon capture and biogas enhancement by carbon dioxide enrichment of anaerobic digesters treating sewage sludge or food waste.

    Science.gov (United States)

    Bajón Fernández, Y; Soares, A; Villa, R; Vale, P; Cartmell, E

    2014-05-01

    The increasing concentration of carbon dioxide (CO2) in the atmosphere and the stringent greenhouse gases (GHG) reduction targets, require the development of CO2 sequestration technologies applicable for the waste and wastewater sector. This study addressed the reduction of CO2 emissions and enhancement of biogas production associated with CO2 enrichment of anaerobic digesters (ADs). The benefits of CO2 enrichment were examined by injecting CO2 at 0, 0.3, 0.6 and 0.9 M fractions into batch ADs treating food waste or sewage sludge. Daily specific methane (CH4) production increased 11-16% for food waste and 96-138% for sewage sludge over the first 24h. Potential CO2 reductions of 8-34% for sewage sludge and 3-11% for food waste were estimated. The capacity of ADs to utilise additional CO2 was demonstrated, which could provide a potential solution for onsite sequestration of CO2 streams while enhancing renewable energy production.

  7. Carbon capture and biogas enhancement by carbon dioxide enrichment of anaerobic digesters treating sewage sludge or food waste.

    Science.gov (United States)

    Bajón Fernández, Y; Soares, A; Villa, R; Vale, P; Cartmell, E

    2014-05-01

    The increasing concentration of carbon dioxide (CO2) in the atmosphere and the stringent greenhouse gases (GHG) reduction targets, require the development of CO2 sequestration technologies applicable for the waste and wastewater sector. This study addressed the reduction of CO2 emissions and enhancement of biogas production associated with CO2 enrichment of anaerobic digesters (ADs). The benefits of CO2 enrichment were examined by injecting CO2 at 0, 0.3, 0.6 and 0.9 M fractions into batch ADs treating food waste or sewage sludge. Daily specific methane (CH4) production increased 11-16% for food waste and 96-138% for sewage sludge over the first 24h. Potential CO2 reductions of 8-34% for sewage sludge and 3-11% for food waste were estimated. The capacity of ADs to utilise additional CO2 was demonstrated, which could provide a potential solution for onsite sequestration of CO2 streams while enhancing renewable energy production. PMID:24632434

  8. Biological hydrogen production from probiotic wastewater as substrate by selectively enriched anaerobic mixed microflora

    Energy Technology Data Exchange (ETDEWEB)

    Sivaramakrishna, D.; Sreekanth, D.; Himabindu, V. [Centre for Environment, Institute of Science and Technology, Jawaharlal Nehru Technological University, Kukatpally, Hyderabad 500072, Andhra Pradesh (India); Anjaneyulu, Y. [TLGVRC, JSU Box 18739, JSU, Jackson, MS 32917-0939 (United States)

    2009-03-15

    Biohydrogen production from probiotic wastewater using mixed anaerobic consortia is reported in this paper. Batch tests are carried out in a 5.0 L batch reactor under constant mesophillic temperature (37 C). The maximum hydrogen yield 1.8 mol-hydrogen/mol-carbohydrate is obtained at an optimum pH of 5.5 and substrate concentration 5 g/L. The maximum hydrogen production rate is 168 ml/h. The hydrogen content in the biogas is more than 65% and no significant methane is observed throughout the study. In addition to hydrogen, acetate, propionate, butyrate and ethanol are found to be the main by-products in the metabolism of hydrogen fermentation. (author)

  9. Syntrophomonas zehnderi sp. nov., an anaerobe that degrades long chain fatty acids in co-culture with Methanobacterium formicicum

    NARCIS (Netherlands)

    Sousa, D.Z.; Smidt, H.; Alves, M.M.; Stams, A.J.M.

    2007-01-01

    An anaerobic, mesophilic, syntrophic fatty-acid-oxidizing bacterium, designated strain OL-4T, was isolated as a co-culture with Methanobacterium formicicum DSM 1535NT from an anaerobic expanded granular sludge bed reactor used to treat an oleate-based effluent. Strain OL-4T degraded oleate, a mono-u

  10. Candidatus Accumulibacter phosphatis clades enriched under cyclic anaerobic and microaerobic conditions simultaneously use different electron acceptors.

    Science.gov (United States)

    Camejo, Pamela Y; Owen, Brian R; Martirano, Joseph; Ma, Juan; Kapoor, Vikram; Santo Domingo, Jorge; McMahon, Katherine D; Noguera, Daniel R

    2016-10-01

    Lab- and pilot-scale simultaneous nitrification, denitrification and phosphorus removal-sequencing batch reactors were operated under cyclic anaerobic and micro-aerobic conditions. The use of oxygen, nitrite, and nitrate as electron acceptors by Candidatus Accumulibacter phosphatis during the micro-aerobic stage was investigated. A complete clade-level characterization of Accumulibacter in both reactors was performed using newly designed qPCR primers targeting the polyphosphate kinase gene (ppk1). In the lab-scale reactor, limited-oxygen conditions led to an alternated dominance of Clade IID and IC over the other clades. Results from batch tests when Clade IC was dominant (i.e., >92% of Accumulibacter) showed that this clade was capable of using oxygen, nitrite and nitrate as electron acceptors for P uptake. A more heterogeneous distribution of clades was found in the pilot-scale system (Clades IIA, IIB, IIC, IID, IA, and IC), and in this reactor, oxygen, nitrite and nitrate were also used as electron acceptors coupled to phosphorus uptake. However, nitrite was not an efficient electron acceptor in either reactor, and nitrate allowed only partial P removal. The results from the Clade IC dominated reactor indicated that either organisms in this clade can simultaneously use multiple electron acceptors under micro-aerobic conditions, or that the use of multiple electron acceptors by Clade IC is due to significant microdiversity within the Accumulibacter clades defined using the ppk1 gene. PMID:27340814

  11. Bio-Hydrogen Production from Pineapple Waste Extract by Anaerobic Mixed Cultures

    OpenAIRE

    Chakkrit Sreela-or; Alissara Reungsang

    2013-01-01

    A statistical experimental design was employed to optimize factors that affect the production of hydrogen from the glucose contained in pineapple waste extract by anaerobic mixed cultures. Results from Plackett-Burman design indicated that substrate concentration, initial pH and FeSO 4 concentration had a statistically significant ( p ≤ 0.05) influence on the hydrogen production potential ( P s ) and the specific hydrogen production rate (SHPR). The path of steepest ascent was undertaken to...

  12. Decreased competiveness of the foodborne pathogen, Campylobacter jejuni, co-culture with the hyper-ammonia anaerobe, Clostridium aminophilum

    Science.gov (United States)

    Campylobacter spp. are a leading bacterial cause of human foodborne illness. When co-cultured in anaerobic Bolton broth with the hyper-ammonia-producing bacterium, Clostridium aminophilum, ammonia accumulation was greater (P 1...

  13. Ammonia inhibition on hydrogen enriched anaerobic digestion of manure under mesophilic and thermophilic conditions

    DEFF Research Database (Denmark)

    Wang, Han; Zhang, Yifeng; Angelidaki, Irini

    2016-01-01

    Capturing of carbon dioxide by hydrogen derived from excess renewable energy (e.g., wind mills) to methane in a microbially catalyzed process offers an attractive technology for biogas production and upgrading. This bioconversion process is catalyzed by hydrogenotrophic methanogens, which are known...... to be sensitive to ammonia. In this study, the tolerance of the biogas process under supply of hydrogen, to ammonia toxicity was studied under mesophilic and thermophilic conditions. When the initial hydrogen partial pressure was 0.5 atm, the methane yield at high ammonia load (7 g NH4+-N L−1) was 41.0% and 22...... methanogens in the hydrogen enriched biogas production and upgrading processes. The highest methane production yield was achieved under 0.5 atm hydrogen partial pressure in batch reactors at all the tested ammonia levels. Furthermore, the thermophilic methanogens at 0.5 atm of hydrogen partial pressure were...

  14. Co-enriching microflora associated with culture based methods to detect Salmonella from tomato phyllosphere.

    Science.gov (United States)

    Ottesen, Andrea R; Gonzalez, Antonio; Bell, Rebecca; Arce, Caroline; Rideout, Steven; Allard, Marc; Evans, Peter; Strain, Errol; Musser, Steven; Knight, Rob; Brown, Eric; Pettengill, James B

    2013-01-01

    The ability to detect a specific organism from a complex environment is vitally important to many fields of public health, including food safety. For example, tomatoes have been implicated numerous times as vehicles of foodborne outbreaks due to strains of Salmonella but few studies have ever recovered Salmonella from a tomato phyllosphere environment. Precision of culturing techniques that target agents associated with outbreaks depend on numerous factors. One important factor to better understand is which species co-enrich during enrichment procedures and how microbial dynamics may impede or enhance detection of target pathogens. We used a shotgun sequence approach to describe taxa associated with samples pre-enrichment and throughout the enrichment steps of the Bacteriological Analytical Manual's (BAM) protocol for detection of Salmonella from environmental tomato samples. Recent work has shown that during efforts to enrich Salmonella (Proteobacteria) from tomato field samples, Firmicute genera are also co-enriched and at least one co-enriching Firmicute genus (Paenibacillus sp.) can inhibit and even kills strains of Salmonella. Here we provide a baseline description of microflora that co-culture during detection efforts and the utility of a bioinformatic approach to detect specific taxa from metagenomic sequence data. We observed that uncultured samples clustered together with distinct taxonomic profiles relative to the three cultured treatments (Universal Pre-enrichment broth (UPB), Tetrathionate (TT), and Rappaport-Vassiliadis (RV)). There was little consistency among samples exposed to the same culturing medias, suggesting significant microbial differences in starting matrices or stochasticity associated with enrichment processes. Interestingly, Paenibacillus sp. (Salmonella inhibitor) was significantly enriched from uncultured to cultured (UPB) samples. Also of interest was the sequence based identification of a number of sequences as Salmonella despite

  15. A Novel Mesophilic Anaerobic Digestion System for Biogas Production and In Situ Methane Enrichment from Coconut Shell Pyroligneous.

    Science.gov (United States)

    Cheng, Jing-Rong; Liu, Xue-Ming; Chen, Zhi-Yi; Zhang, You-Sheng; Zhang, Ye-Hui

    2016-04-01

    A novel mesophilic anaerobic digestion process with detoxification-treated coconut shell pyroligneous was established, exhibiting an effective advantage in biogas production. The pyroligneous collected contained 166.2 g l(-1) acetic acid, indicating great potential for biogas production. Detoxification was an effective way of simultaneously enriching biodegradable ingredients and removing inhibitors (mainly as phenols and organic acids) for digestion process. The digestion process lasted 96 h and fermentation characteristics (chemical oxygen demand (COD) removal ratio, volatile fatty acid (VFA) consumptions, pH, total gas, methane yield, and phenol removal efficiency) were measured. The experiments successfully explored the optimum detoxification parameters, oxidized with 10 % H2O2 followed by overliming, and demonstrated 89.3 % COD removal, 91.4 % methane content, 0.305 LCH4/g COD removed CH4 yield, and 88.81 % phenol removal ratio. This study provided clues to overcome the negative effects of inhibitors in pyroligneous on biogas production. The findings could contribute to significant process in detoxified pretreatment of pyroligneous and develop an economically feasible technology for treating pyroligneous after producing charcoal. PMID:26638211

  16. Atrazine and its metabolites degradation in mineral salts medium and soil using an enrichment culture.

    Science.gov (United States)

    Kumar, Anup; Singh, Neera

    2016-03-01

    An atrazine-degrading enrichment culture was used to study degradation of atrazine metabolites viz. hydroxyatrazine, deethylatrazine, and deisopropylatrazine in mineral salts medium. Results suggested that the enrichment culture was able to degrade only hydroxyatrazine, and it was used as the sole source of carbon and nitrogen. Hydroxyatrazine degradation slowed down when sucrose and/or ammonium hydrogen phosphate were supplemented as the additional sources of carbon and nitrogen, respectively. The enrichment culture could degrade high concentrations of atrazine (up to 110 μg/mL) in mineral salts medium, and neutral pH was optimum for atrazine degradation. Further, except in an acidic soil, enrichment culture was able to degrade atrazine in three soil types having different physico-chemical properties. Raising the pH of acidic soil to neutral or alkaline enabled the enrichment culture to degrade atrazine suggesting that acidic pH inhibited atrazine-degrading ability. The study suggested that the enrichment culture can be successfully utilized to achieve complete degradation of atrazine and its persistent metabolite hydroxyatrazine in the contaminated soil and water.

  17. Enrichment methodology to increase the positivity of cultures from body fluids

    Directory of Open Access Journals (Sweden)

    Alessandra Valle Daur

    2006-12-01

    Full Text Available Isolation and identification of etiological agents found in body fluids can be of critical importance for the recovery of patients suffering from potentially-severe infections, which are often followed by serious sequels. Eighty-two samples of different body fluids were analyzed using two different methods: (1 the conventional culture method (agar plating and (2 the enrichment culture technique, using the Bact/Alert® blood culture bottle. The number of positive cultures increased on average from 9.7% to 23.1% with the enrichment culture technique. Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus were the most frequently isolated bacteria. The enrichment method could provide a more accurate means the identifying etiological agents.

  18. Production of functional killer protein in batch cultures upon a shift from aerobic to anaerobic conditions

    Directory of Open Access Journals (Sweden)

    Gildo Almeida da Silva

    2011-06-01

    Full Text Available The aim of this work was to study the production of functional protein in yeast culture. The cells of Saccharomyces cerevisiae Embrapa 1B (K+R+ killed a strain of Saccharomyces cerevisiae Embrapa 26B (K-R-in grape must and YEPD media. The lethal effect of toxin-containing supernatant and the effect of aeration upon functional killer production and the correlation between the products of anaerobic metabolism and the functional toxin formation were evaluated. The results showed that at low sugar concentration, the toxin of the killer strain of Sacch. cerevisiae was only produced under anaerobic conditions . The system of killer protein production showed to be regulated by Pasteur and Crabtree effects. As soon as the ethanol was formed, the functional killer toxin was produced. The synthesis of the active killer toxin seemed to be somewhat associated with the switch to fermentation process and with concomitant alcohol dehydrogenase (ADH activity.

  19. Co-occurrence of Methanosarcina mazei and Geobacteraceae in an iron(III-reducing enrichment culture

    Directory of Open Access Journals (Sweden)

    Shiling eZheng

    2015-09-01

    Full Text Available Methanosaeta harundinacea and Methanosarcina barkeri, known as classic acetoclastic methanogens, are capable of directly accepting electrons from Geobacter metallireducens for the reduction of carbon dioxide to methane, having been revealed as direct interspecies electron transfer (DIET in the laboratory co-cultures. However, whether their co-occurrences are ubiquitous in the iron (III-reducing environments and the other species of acetoclastic methanogens such as Methanosarcina mazei are capable of DIET are still unknown. Instead of initiating the co-cultures with pure cultures, two-step cultivation was employed to selectively enrich iron (III-reducing microorganisms in a coastal gold mining river, Jiehe River, with rich iron content in the sediments. First, iron (III reducers including Geobacteraceae were successfully enriched by 3-months successive culture on amorphous Fe(III oxides as electron acceptor and acetate as electron donor. High-throughput Illumina sequencing, terminal restriction fragment length polymorphism (T-RFLP and clone library analysis based on 16S rRNA genes revealed that the enrichment cultures actively contained the bacteria belong to Geobacteraceae and Bacilli, exclusively dominated by the archaea belong to Methanosarcinaceae. Second, the enrichment cultures including methanogens and Geobacteraceae were transferred with ethanol as alternative electron donor. Remarkably, aggregates were successively formed in the enrichments after three transfers. The results revealed by RNA-based analysis demonstrate that the co-occurrence of Methanosarcina mazei and Geobacteraceae in an iron (III-reducing enrichment culture. Furthermore, the aggregates, as close physical contact, formed in the enrichment culture, indicate that DIET could be a possible option for interspecies electron transfer in the aggregates.

  20. Growth and nitrate reduction of Beggiatoa filaments studied in enrichment cultures

    DEFF Research Database (Denmark)

    Kamp, Anja

    in oxygen-sulphide gradient tubes, and observed with a camera system. Growth mode, breakage, and movement directions of Beggiatoa filaments were documented via time-lapse video recording. The initial doubling time of cells was 15.7 ±1.3 h (mean ±SD; room temperature). Filaments grew up to an average length......In this thesis, several aspects of the gliding, filamentous, colourless sulphur bacteria Beggiatoa were investigated. The first part of this thesis addressed the growth mode, breakage of filaments for multiplication, and movement directions of filaments of Beggiatoa. Marine Beggiatoa were enriched...... sediments, and affect the benthic sulphur cycle. In addition, Beggiatoa may influence the nitrogen cycle when they use nitrate anaerobically as an alternative electron acceptor in place of oxygen. The ability of freshwater and marine Beggiatoa to oxidise sulphide anaerobically with nitrate has been studied...

  1. Respiration and respiratory enzyme activity in aerobic and anaerobic cultures of the marine denitrifying bacterium, Pseudomonas perfectomarinus

    Science.gov (United States)

    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.

  2. Mixing Intensity Effects of Attached Growth on Enriched Anammox Cultures

    Directory of Open Access Journals (Sweden)

    Pongsak Noophan

    2015-01-01

    Full Text Available Anaerobic ammonium oxidation (anammox is a promising new technology for the treatment of wastewater with high ammonium and low carbon concentrations. Earlier work suggests that optimal processing would be realized within a sequencing batch reactor (SBR. However, the relatively slow growth of anammox bacteria inhibits the rates of nitrogen removal and biomass yielding. Improved anammox performance has been demonstrated when the bacteria are in granular form or attached to a growth medium. Little has been reported concerning the effect of mixing rate on nitrogen (N removal with attached anammox bacteria. This work subjected anammox bacteria attached to polystyrene sponge in SBR to various intensities of impeller mixing and studied the effect on NH4+ and NO2- removal. Nitrogen processing was virtually the same with velocity gradient values between 13.5 and 222 s-1. More vigorous mixing at 407 and 666 s-1 values significantly inhibited N removal, likely due to detachment of bacteria from the growth medium. Following the poor N removal at the two higher mixing intensities, agitation was reduced to 24.8 s-1 velocity gradient value. Recovery of N removal rates required 2-3 weeks, the slow time attributed to slow reattachment to the growth medium. Denaturing gradient gel electrophoresis (DGGE analysis identified the prominent anammox species in the experimental study as Candidatus Brocadia anammoxidans and Candidatus Kuenenia stuttgartiensis.

  3. Ca2+ enrichment in culture medium potentiates effect of oligonucleotides.

    Science.gov (United States)

    Hori, Shin-Ichiro; Yamamoto, Tsuyoshi; Waki, Reiko; Wada, Shunsuke; Wada, Fumito; Noda, Mio; Obika, Satoshi

    2015-10-30

    Antisense and RNAi-related oligonucleotides have gained attention as laboratory tools and therapeutic agents based on their ability to manipulate biological events in vitro and in vivo. We show that Ca(2+) enrichment of medium (CEM) potentiates the in vitro activity of multiple types of oligonucleotides, independent of their net charge and modifications, in various cells. In addition, CEM reflects in vivo silencing activity more consistently than conventional transfection methods. Microscopic analysis reveals that CEM provides a subcellular localization pattern of oligonucleotides resembling that obtained by unassisted transfection, but with quantitative improvement. Highly monodispersed nanoparticles ~100 nm in size are found in Ca(2+)-enriched serum-containing medium regardless of the presence or absence of oligonucleotides. Transmission electron microscopy analysis reveals that the 100-nm particles are in fact an ensemble of much smaller nanoparticles (ϕ ∼ 15 nm). The presence of these nanoparticles is critical for the efficient uptake of various oligonucleotides. In contrast, CEM is ineffective for plasmids, which are readily transfected via the conventional calcium phosphate method. Collectively, CEM enables a more accurate prediction of the systemic activity of therapeutic oligonucleotides, while enhancing the broad usability of oligonucleotides in the laboratory. PMID:26101258

  4. Ca2+ enrichment in culture medium potentiates effect of oligonucleotides.

    Science.gov (United States)

    Hori, Shin-Ichiro; Yamamoto, Tsuyoshi; Waki, Reiko; Wada, Shunsuke; Wada, Fumito; Noda, Mio; Obika, Satoshi

    2015-10-30

    Antisense and RNAi-related oligonucleotides have gained attention as laboratory tools and therapeutic agents based on their ability to manipulate biological events in vitro and in vivo. We show that Ca(2+) enrichment of medium (CEM) potentiates the in vitro activity of multiple types of oligonucleotides, independent of their net charge and modifications, in various cells. In addition, CEM reflects in vivo silencing activity more consistently than conventional transfection methods. Microscopic analysis reveals that CEM provides a subcellular localization pattern of oligonucleotides resembling that obtained by unassisted transfection, but with quantitative improvement. Highly monodispersed nanoparticles ~100 nm in size are found in Ca(2+)-enriched serum-containing medium regardless of the presence or absence of oligonucleotides. Transmission electron microscopy analysis reveals that the 100-nm particles are in fact an ensemble of much smaller nanoparticles (ϕ ∼ 15 nm). The presence of these nanoparticles is critical for the efficient uptake of various oligonucleotides. In contrast, CEM is ineffective for plasmids, which are readily transfected via the conventional calcium phosphate method. Collectively, CEM enables a more accurate prediction of the systemic activity of therapeutic oligonucleotides, while enhancing the broad usability of oligonucleotides in the laboratory.

  5. Enrichment Culture of Hydrogen Fermentation Microorganisms and Analysis of Microbial Communities

    Science.gov (United States)

    Huang, Xiaoyu; Matsumoto, Akiko; Ohnishi, Akihiro; Sakamoto, Masaru; Fujimoto, Naoshi; Suzuki, Masaharu

    The present study was aimed at enrichment of hydrogen fermentative microflora that can utilize garbage as fermentation substrate. It was shown that stable hydrogen fermentation was performed using enriched microbes from sewage sludge compost. During the enrichment culture, the microflora were analyzed by the FISH method and the PCR-DGGE method. As a result, predominant microbes of hydrogen production were determined to be from the genus Clostridium belonging to a Gram positive Low G+C group. Furthermore, it was supposed that genus Bacillus contributed to the stability of hydrogen productivity from garbage by genus Clostridium. In the batch culture, under pH control at 6.0, it was ascertained that enriched microflora obtained from sewage sludge compost had sufficient hydrogen productivity using garbage, and yielded 2.03mol-H2/mol-hexose. It is supposed that the microflora of sewage sludge compost is effective as inoculum of the hydrogen fermentation system when using garbage as substrate.

  6. Resource recovery from organic waste streams by microbial enrichment cultures

    OpenAIRE

    Tamis, J.

    2015-01-01

    Polyhydroxyalkanoate (PHA) is a natural product that can potentially replace a part of the chemicals and plastics derived from fossil sources. One of the main barriers for market entry of PHA is its relatively high price compared to conventional (fossil) feedstocks. This high price is related to current industrial production methods which are based on the cultivation of pure microbial cultures of a single species that a.o. has to be protected from contaminations from unwanted microorganisms t...

  7. Differential gene expression profiling of enriched human spermatogonia after short- and long-term culture.

    Science.gov (United States)

    Conrad, Sabine; Azizi, Hossein; Hatami, Maryam; Kubista, Mikael; Bonin, Michael; Hennenlotter, Jörg; Renninger, Markus; Skutella, Thomas

    2014-01-01

    This study aimed to provide a molecular signature for enriched adult human stem/progenitor spermatogonia during short-term (differentiation/spermatogenesis pathway were highly expressed in enriched short-term cultured spermatogonia. After long-term culture, a proportion of cells retained and aggravated the "spermatogonial" gene expression profile with the expression of germ and pluripotency-associated genes, while in the majority of long-term cultured cells this molecular profile, typical for the differentiation pathway, was reduced and more genes related to the extracellular matrix production and attachment were expressed. The approach we provide here to study the molecular status of in vitro cultured spermatogonia may be important to optimize the culture conditions and to evaluate the germ cell plasticity in the future.

  8. Differential Gene Expression Profiling of Enriched Human Spermatogonia after Short- and Long-Term Culture

    Directory of Open Access Journals (Sweden)

    Sabine Conrad

    2014-01-01

    Full Text Available This study aimed to provide a molecular signature for enriched adult human stem/progenitor spermatogonia during short-term (<2 weeks and long-term culture (up to more than 14 months in comparison to human testicular fibroblasts and human embryonic stem cells. Human spermatogonia were isolated by CD49f magnetic activated cell sorting and collagen−/laminin+ matrix binding from primary testis cultures obtained from ten adult men. For transcriptomic analysis, single spermatogonia-like cells were collected based on their morphology and dimensions using a micromanipulation system from the enriched germ cell cultures. Immunocytochemical, RT-PCR and microarray analyses revealed that the analyzed populations of cells were distinct at the molecular level. The germ- and pluripotency-associated genes and genes of differentiation/spermatogenesis pathway were highly expressed in enriched short-term cultured spermatogonia. After long-term culture, a proportion of cells retained and aggravated the “spermatogonial” gene expression profile with the expression of germ and pluripotency-associated genes, while in the majority of long-term cultured cells this molecular profile, typical for the differentiation pathway, was reduced and more genes related to the extracellular matrix production and attachment were expressed. The approach we provide here to study the molecular status of in vitro cultured spermatogonia may be important to optimize the culture conditions and to evaluate the germ cell plasticity in the future.

  9. Detection of Salmonella invA gene in shrimp enrichment culture by polymerase chain reaction.

    Science.gov (United States)

    Upadhyay, Bishnu Prasad; Utrarachkij, Fuangfa; Thongshoob, Jarinee; Mahakunkijcharoen, Yuvadee; Wongchinda, Niracha; Suthienkul, Orasa; Khusmith, Srisin

    2010-03-01

    Contamination of seafood with salmonellae is a major public health concern. Detection of Salmonella by standard culture methods is time consuming. In this study, an enrichment culture step prior to polymerase chain reaction (PCR) was applied to detect 284 bp fragment of Salmonella invA in comparison with the conventional culture method in 100 shrimp samples collected from four different shrimp farms and fresh food markets around Bangkok. Samples were pre-enriched in non-selective lactose broth (LB) and selective tetrathionate broth (TTB). PCR detection limit was 10 pg and 10(4) cfu/ml of viable salmonellae with 100% specificity. PCR assay detected 19 different Salmonella serovars belonging to 8 serogroups (B, C1, C2-C3, D1, E1, E4 and K) commonly found in clinical and environmental samples in Thailand. The detection rate of PCR following TTB enrichment (24%) was higher than conventional culture method (19%). PCR following TTB, but not in LB enrichment allowed salmonella detection with 84% sensitivity, 90% specificity and 89% accuracy. Shrimp samples collected from fresh food markets had higher levels of contaminated salmonellae than those from shrimp farms. The results indicated that incorporation of an enrichment step prior to PCR has the potential to be applied for detection of naturally contaminated salmonellae in food, environment and clinical samples.

  10. Preparation of Rodent Primary Cultures for Neuron–Glia, Mixed Glia, Enriched Microglia, and Reconstituted Cultures with Microglia

    OpenAIRE

    Chen, Shih-Heng; Oyarzabal, Esteban A.; Hong, Jau-Shyong

    2013-01-01

    Microglia, neurons, and macroglia (astrocytes and oligodendrocytes) are the major cell types in the central nervous system. In the past decades, primary microglia-enriched cultures have been widely used to study the biological functions of microglia in vitro. In order to study the interactions between microglia and other brain cells, neuron–glia, neuron–microglia, and mixed glia cultures were developed. The aim of this chapter is to provide basic and adaptable protocols for the preparation of...

  11. Enriching Chinese Cultural Heritage at the Queens Library

    Directory of Open Access Journals (Sweden)

    Gary E. Strong

    2001-10-01

    Full Text Available

    頁次:13-18

    The Queens Borough Public Library through its New Americans Program has been providing opportunities for the Chinese Community to experience quality library service for many years. By building collections, providing opportunities to learn English, providing job information, coping skills classes, cultural programs and electronic access to Chinese vernacular script, the Library provides a unique public library experience to its many immigrants. Through demographic analysis, the Library places its collections in the communities where immigrants live and provides programs of relevance to celebrate the cultures and traditions of the Chinese community.

  12. The Role of Benzoate in Anaerobic Degradation of Terephthalate

    OpenAIRE

    Kleerebezem, Robbert; Pol, Look W. Hulshoff; Lettinga, Gatze

    1999-01-01

    The effects of acetate, benzoate, and periods without substrate on the anaerobic degradation of terephthalate (1,4-benzene-dicarboxylate) by a syntrophic methanogenic culture were studied. The culture had been enriched on terephthalate and was capable of benzoate degradation without a lag phase. When incubated with a mixture of benzoate and terephthalate, subsequent degradation with preference for benzoate was observed. Both benzoate and acetate inhibited the anaerobic degradation of terephth...

  13. Reductive Dechlorination of Carbon Tetrachloride by Tetrachloroethene and Trichloroethene Respiring Anaerobic Mixed Cultures

    Science.gov (United States)

    Vickstrom, K. E.; Azizian, M.; Semprini, L.

    2015-12-01

    Carbon tetrachloride (CT) is a toxic and recalcitrant groundwater contaminant with the potential to form a broad range of transformation products. Of the possible biochemical pathways through which CT can be degraded, reductive dehalogenation to less chlorinated compounds and mineralization to carbon dioxide (CO2) appear to be the most frequently utilized pathways by anaerobic organisms. Results will be presented from batch experiments of CT degradation by the Evanite (EV), Victoria Strain (VS) and Point Mugu (PM) anaerobic dechlorinating cultures. The cultures are grown in chemostats and are capable of transforming tetrachloroethene (PCE) or trichloroethene (TCE) to ethene by halorespiration via reductive dehalogenase enzymes. For the batch CT transformation tests, the cells along with supernatant were harvested from chemostats fed PCE or TCE, but never CT. The batch reactors were initially fed 0.0085 mM CT and an excess of formate (EV and VS) or lactate (PM) as electron donor. Transformation of CT was 100% with about 20% converted to chloroform (CF) and undetected products. Multiple additions of CT showed a slowing of pseudo first-order CT transformation rates across all cultures. Batch reactors were then established and fed 0.085 mM CT with an excess of electron donor in order to better quantify the reductive pathway. CT was transformed to CF and dichloromethane (DCM), with trace amounts of chloromethane (CM) detected. Between 60-90% of the mass added to the system was accounted for, showing that the majority of the carbon tetrachloride present is being reductively dehalogenated. Results from batch reactors that were poisoned using sodium azide, and from reactors not provided electron donor will be presented to distinguish between biotic and abiotic reactions. Furthermore, results from reactors prepared with acetylene (a potent, reversible inhibitor of reductive dehalogenases (1)) will be presented as a means of identifying the enzymes involved in the

  14. Comparative metagenomics of three Dehalococcoides-containing enrichment cultures: the role of the non-dechlorinating community

    Directory of Open Access Journals (Sweden)

    Hug Laura A

    2012-07-01

    Full Text Available Abstract Background The Dehalococcoides are strictly anaerobic bacteria that gain metabolic energy via the oxidation of H2 coupled to the reduction of halogenated organic compounds. Dehalococcoides spp. grow best in mixed microbial consortia, relying on non-dechlorinating members to provide essential nutrients and maintain anaerobic conditions. A metagenome sequence was generated for the dechlorinating mixed microbial consortium KB-1. A comparative metagenomic study utilizing two additional metagenome sequences for Dehalococcoides-containing dechlorinating microbial consortia was undertaken to identify common features that are provided by the non-dechlorinating community and are potentially essential to Dehalococcoides growth. Results The KB-1 metagenome contained eighteen novel homologs to reductive dehalogenase genes. The metagenomes obtained from the three consortia were automatically annotated using the MG-RAST server, from which statistically significant differences in community composition and metabolic profiles were determined. Examination of specific metabolic pathways, including corrinoid synthesis, methionine synthesis, oxygen scavenging, and electron-donor metabolism identified the Firmicutes, methanogenic Archaea, and the ∂-Proteobacteria as key organisms encoding these pathways, and thus potentially producing metabolites required for Dehalococcoides growth. Conclusions Comparative metagenomics of the three Dehalococcoides-containing consortia identified that similarities across the three consortia are more apparent at the functional level than at the taxonomic level, indicating the non-dechlorinating organisms’ identities can vary provided they fill the same niche within a consortium. Functional redundancy was identified in each metabolic pathway of interest, with key processes encoded by multiple taxonomic groups. This redundancy likely contributes to the robust growth and dechlorination rates in dechlorinating enrichment

  15. Breast Cancer Stem Cell Culture and Enrichment Using Poly(ε-Caprolactone) Scaffolds.

    Science.gov (United States)

    Palomeras, Sònia; Rabionet, Marc; Ferrer, Inés; Sarrats, Ariadna; Garcia-Romeu, Maria Luisa; Puig, Teresa; Ciurana, Joaquim

    2016-01-01

    The cancer stem cell (CSC) population displays self-renewal capabilities, resistance to conventional therapies, and a tendency to post-treatment recurrence. Increasing knowledge about CSCs' phenotype and functions is needed to investigate new therapeutic strategies against the CSC population. Here, poly(ε-caprolactone) (PCL), a biocompatible polymer free of toxic dye, has been used to fabricate scaffolds, solid structures suitable for 3D cancer cell culture. It has been reported that scaffold cell culture enhances the CSCs population. A RepRap BCN3D+ printer and 3 mm PCL wire were used to fabricate circular scaffolds. PCL design and fabrication parameters were first determined and then optimized considering several measurable variables of the resulting scaffolds. MCF7 breast carcinoma cell line was used to assess scaffolds adequacy for 3D cell culture. To evaluate CSC enrichment, the Mammosphere Forming Index (MFI) was performed in 2D and 3D MCF7 cultures. Results showed that the 60° scaffolds were more suitable for 3D culture than the 45° and 90° ones. Moreover, 3D culture experiments, in adherent and non-adherent conditions, showed a significant increase in MFI compared to 2D cultures (control). Thus, 3D cell culture with PCL scaffolds could be useful to improve cancer cell culture and enrich the CSCs population. PMID:27120585

  16. Breast Cancer Stem Cell Culture and Enrichment Using Poly(ε-Caprolactone Scaffolds

    Directory of Open Access Journals (Sweden)

    Sònia Palomeras

    2016-04-01

    Full Text Available The cancer stem cell (CSC population displays self-renewal capabilities, resistance to conventional therapies, and a tendency to post-treatment recurrence. Increasing knowledge about CSCs’ phenotype and functions is needed to investigate new therapeutic strategies against the CSC population. Here, poly(ε-caprolactone (PCL, a biocompatible polymer free of toxic dye, has been used to fabricate scaffolds, solid structures suitable for 3D cancer cell culture. It has been reported that scaffold cell culture enhances the CSCs population. A RepRap BCN3D+ printer and 3 mm PCL wire were used to fabricate circular scaffolds. PCL design and fabrication parameters were first determined and then optimized considering several measurable variables of the resulting scaffolds. MCF7 breast carcinoma cell line was used to assess scaffolds adequacy for 3D cell culture. To evaluate CSC enrichment, the Mammosphere Forming Index (MFI was performed in 2D and 3D MCF7 cultures. Results showed that the 60° scaffolds were more suitable for 3D culture than the 45° and 90° ones. Moreover, 3D culture experiments, in adherent and non-adherent conditions, showed a significant increase in MFI compared to 2D cultures (control. Thus, 3D cell culture with PCL scaffolds could be useful to improve cancer cell culture and enrich the CSCs population.

  17. Using Enrichment Clusters to Address the Needs of Culturally and Linguistically Diverse Learners

    Science.gov (United States)

    Allen, Jennifer K.; Robbins, Margaret A.; Payne, Yolanda Denise; Brown, Katherine Backes

    2016-01-01

    Using data from teacher interviews, classroom observations, and a professional development workshop, this article explains how one component of the schoolwide enrichment model (SEM) has been implemented at a culturally diverse elementary school serving primarily Latina/o and African American students. Based on a broadened conception of giftedness,…

  18. Quantitative proteome and transcriptome analysis of the archaeon Thermoplasma acidophilum cultured under aerobic and anaerobic conditions.

    Science.gov (United States)

    Sun, Na; Pan, Cuiping; Nickell, Stephan; Mann, Matthias; Baumeister, Wolfgang; Nagy, István

    2010-09-01

    A comparative proteome and transcriptome analysis of Thermoplasma acidophilum cultured under aerobic and anaerobic conditions has been performed. One-thousand twenty-five proteins were identified covering 88% of the cytosolic proteome. Using a label-free quantitation method, we found that approximately one-quarter of the identified proteome (263 proteins) were significantly induced (>2 fold) under anaerobic conditions. Thirty-nine macromolecular complexes were identified, of which 28 were quantified and 15 were regulated under anaerobiosis. In parallel, a whole genome cDNA microarray analysis was performed showing that the expression levels of 445 genes were influenced by the absence of oxygen. Interestingly, more than 40% of the membrane protein-encoding genes (145 out of 335 ORFs) were up- or down-regulated at the mRNA level. Many of these proteins are functionally associated with extracellular protein or peptide degradation or ion and amino acid transport. Comparison of the transcriptome and proteome showed only a weak positive correlation between mRNA and protein expression changes, which is indicative of extensive post-transcriptional regulatory mechanisms in T. acidophilum. Integration of transcriptomics and proteomics data generated hypotheses for physiological adaptations of the cells to anaerobiosis, and the quantitative proteomics data together with quantitative analysis of protein complexes provide a platform for correlation of MS-based proteomics studies with cryo-electron tomography-based visual proteomics approaches.

  19. Chemical characterization and anaerobic biodegradability of hydrothermal liquefaction aqueous products from mixed-culture wastewater algae.

    Science.gov (United States)

    Tommaso, Giovana; Chen, Wan-Ting; Li, Peng; Schideman, Lance; Zhang, Yuanhui

    2015-02-01

    This study examined the chemical characteristics and the anaerobic degradability of the aqueous product from hydrothermal liquefaction (HTL-ap) from the conversion of mixed-culture algal biomass grown in a wastewater treatment system. The effects of the HTL reaction times from 0 to 1.5 h, and reaction temperatures from 260 °C to 320 °C on the anaerobic degradability of the HTL-ap were quantified using biomethane potential assays. Comparing chemical oxygen demand data for HTL-ap from different operating conditions, indicated that organic matter may partition from organic phase to aqueous phase at 320 °C. Moderate lag phase and the highest cumulative methane production were observed when HTL-ap was obtained at 320 °C. The longest lag phase and the smallest production rate were observed in the process fed with HTL-ap obtained at 300 °C. Nevertheless, after overcoming adaptation issues, this HTL-ap led to the second highest accumulated specific methane production. Acetogenesis was identified as a possible rate-limiting pathway. PMID:25455086

  20. 16S rRNA gene sequencing in routine identification of anaerobic bacteria isolated from blood cultures

    DEFF Research Database (Denmark)

    Justesen, Ulrik Stenz; Skov, Marianne Nielsine; Knudsen, Elisa;

    2010-01-01

    A comparison between conventional identification and 16S rRNA gene sequencing of anaerobic bacteria isolated from blood cultures in a routine setting was performed (n = 127). With sequencing, 89% were identified to the species level, versus 52% with conventional identification. The times...

  1. Treatment and electricity harvesting from sulfate/sulfide-containing wastewaters using microbial fuel cell with enriched sulfate-reducing mixed culture

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Duu-Jong, E-mail: cedean@mail.ntust.edu.tw [Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan (China); Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan (China); Lee, Chin-Yu [Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan (China); Chang, Jo-Shu [Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Center for Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan (China); Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan, Taiwan (China)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer We started up microbial fuel cell (MFC) using enriched sulfate-reducing mixed culture. Black-Right-Pointing-Pointer Sulfate-reducing bacteria and anode-respiring bacteria were enriched in anodic biofilms. Black-Right-Pointing-Pointer The MFC effectively remove sulfate to elementary sulfur in the presence of lactate. Black-Right-Pointing-Pointer The present device can treat sulfate laden wastewaters with electricity harvesting. - Abstract: Anaerobic treatment of sulfate-laden wastewaters can produce excess sulfide, which is corrosive to pipelines and is toxic to incorporated microorganisms. This work started up microbial fuel cell (MFC) using enriched sulfate-reducing mixed culture as anodic biofilms and applied the so yielded MFC for treating sulfate or sulfide-laden wastewaters. The sulfate-reducing bacteria in anodic biofilm effectively reduced sulfate to sulfide, which was then used by neighboring anode respiring bacteria (ARB) as electron donor for electricity production. The presence of organic carbons enhanced MFC performance since the biofilm ARB were mixotrophs that need organic carbon to grow. The present device introduces a route for treating sulfate laden wastewaters with electricity harvesting.

  2. Newly Cultured Bacteria with Broad Diversity Isolated from Eight-Week Continuous Culture Enrichments of Cow Feces on Complex Polysaccharides

    OpenAIRE

    Ziemer, Cherie J.

    2014-01-01

    One of the functions of the mammalian large intestinal microbiota is the fermentation of plant cell wall components. In ruminant animals, the majority of their nutrients are obtained via pregastric fermentation; however, up to 20% can be recovered from microbial fermentation in the large intestine. Eight-week continuous culture enrichments of cattle feces with cellulose and xylan-pectin were used to isolate bacteria from this community. A total of 459 bacterial isolates were classified phylog...

  3. Lactic acid production from potato peel waste by anaerobic sequencing batch fermentation using undefined mixed culture.

    Science.gov (United States)

    Liang, Shaobo; McDonald, Armando G; Coats, Erik R

    2015-11-01

    Lactic acid (LA) is a necessary industrial feedstock for producing the bioplastic, polylactic acid (PLA), which is currently produced by pure culture fermentation of food carbohydrates. This work presents an alternative to produce LA from potato peel waste (PPW) by anaerobic fermentation in a sequencing batch reactor (SBR) inoculated with undefined mixed culture from a municipal wastewater treatment plant. A statistical design of experiments approach was employed using set of 0.8L SBRs using gelatinized PPW at a solids content range from 30 to 50 g L(-1), solids retention time of 2-4 days for yield and productivity optimization. The maximum LA production yield of 0.25 g g(-1) PPW and highest productivity of 125 mg g(-1) d(-1) were achieved. A scale-up SBR trial using neat gelatinized PPW (at 80 g L(-1) solids content) at the 3 L scale was employed and the highest LA yield of 0.14 g g(-1) PPW and a productivity of 138 mg g(-1) d(-1) were achieved with a 1 d SRT. PMID:25708409

  4. Anaerobic bacteria grow within Candida albicans biofilms and induce biofilm formation in suspension cultures.

    Science.gov (United States)

    Fox, Emily P; Cowley, Elise S; Nobile, Clarissa J; Hartooni, Nairi; Newman, Dianne K; Johnson, Alexander D

    2014-10-20

    The human microbiome contains diverse microorganisms, which share and compete for the same environmental niches. A major microbial growth form in the human body is the biofilm state, where tightly packed bacterial, archaeal, and fungal cells must cooperate and/or compete for resources in order to survive. We examined mixed biofilms composed of the major fungal species of the gut microbiome, Candida albicans, and each of five prevalent bacterial gastrointestinal inhabitants: Bacteroides fragilis, Clostridium perfringens, Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis. We observed that biofilms formed by C. albicans provide a hypoxic microenvironment that supports the growth of two anaerobic bacteria, even when cultured in ambient oxic conditions that are normally toxic to the bacteria. We also found that coculture with bacteria in biofilms induces massive gene expression changes in C. albicans, including upregulation of WOR1, which encodes a transcription regulator that controls a phenotypic switch in C. albicans, from the "white" cell type to the "opaque" cell type. Finally, we observed that in suspension cultures, C. perfringens induces aggregation of C. albicans into "mini-biofilms," which allow C. perfringens cells to survive in a normally toxic environment. This work indicates that bacteria and C. albicans interactions modulate the local chemistry of their environment in multiple ways to create niches favorable to their growth and survival.

  5. The importance of local events in enriching the cultural and tourism offer

    Directory of Open Access Journals (Sweden)

    Spasojević Bojana

    2013-01-01

    Full Text Available In the municipality of Ruma twenty five events take place per year. Most of these events have local or regional character. The event "Christmas Street" is the youngest event which is being organized in Ruma, the first time was held in late 2011. The subject of this paper is to study this event that complements the existing tourism offer of Ruma as potential tourist destination of Vojvodina. The aim of this paper is to highlight the importance of this event in the cultural enrichment of Ruma and its surroundings as well as the development of event tourism and positive presentation of the Municipality of Ruma. The significance of local events for enrichment of cultural-tourism offer will be presented as Case study of “Christmas street” in the city of Ruma. [Projekat Ministarstva nauke Republike Srbije, br. 176020

  6. Developments in techniques for the isolation, enrichment, main culture conditions and identification of spermatogonial stem cells.

    Science.gov (United States)

    He, Yanan; Chen, Xiaoli; Zhu, Huabin; Wang, Dong

    2015-12-01

    The in vitro culture system of spermatogonial stem cells (SSCs) provides a basis for studies on spermatogenesis, and also contributes to the development of new methods for the preservation of livestock and animal genetic modification. In vitro culture systems have mainly been established for mouse SSCs, but are lacking for farm animals. We reviewed and analyzed the current progress in SSC techniques such as isolation, purification, cultivation and identification. Based on the published studies, we concluded that two-step enzyme digestion and magnetic-activated cell sorting are fast becoming the main methods for isolation and enrichment of SSCs. With regard to the culture systems, serum and feeders were earlier thought to play an important role in the self-renewal and proliferation of SSCs, but serum- and feeder-free culture systems as a means of overcoming the limitations of SSC differentiation in long-term SSC culture are being explored. However, there is still a need to establish more efficient and ideal culture systems that can also be used for SSC culture in larger mammals. Although the lack of SSC-specific surface markers has seriously affected the efficiency of purification and identification, the transgenic study is helpful for our identification of SSCs. Therefore, future studies on SSC techniques should focus on improving serum- and feeder-free culture techniques, and discovering and identifying specific surface markers of SSCs, which will provide new ideas for the optimization of SSC culture systems for mice and promote related studies in farm animals. PMID:25749914

  7. Enrichment of prostate cancer stem cells from primary prostate cancer cultures of biopsy samples

    OpenAIRE

    Wang, Shunqi; Huang, Shengsong; Zhao, Xin; Zhang, Qimin; Wu, Min; Sun, Feng; Han, Gang; Wu, Denglong

    2013-01-01

    This study was to enrich prostate cancer stem cells (PrCSC) from primary prostate cancer cultures (PPrCC). Primary prostate cancer cells were amplified in keratinocyte serum-free medium with epidermal growth factor (EGF) and bovine pituitary extract (BPE), supplemented with leukemia inhibitory factor (LIF), stem cell factor (SCF) and cholera toxin. After amplification, cells were transferred into ultra-low attachment dishes with serum-free DMEM/F12 medium, supplemented with EGF, basic fibrobl...

  8. Fatty Acids Profile during Anaerobic Digestion of Night Soil-Effect of temperature, Calcium Carbonate and Selectively-enriched Inoculum

    OpenAIRE

    S. I. Alam; Singh, L; Maurya, M. S.

    1996-01-01

    Anaerobic biodegradation of night soil was carried out at 5-30 degree centigrade with 1.8-10.62 per cent volatile solids (VS). Biogas production increased with the temperature and VS up to 6.2 per cent. Further increase in VS caused higher Volatile fatty acids (VFA) accumulation resulting in decreased gas production. Acetate and propionate accounted for 62-83 per cent of total VFA. Butyrate to isobutyrate ratio increased with VS. Calcium Carbonate promoted VS degradation, biogas produc...

  9. Microbial community analysis in sludge of anaerobic wastewater treatment systems : integrated culture-dependent and culture-independent approaches

    NARCIS (Netherlands)

    Roest, C.

    2007-01-01

    The need for clean water is increasing and anaerobic wastewater treatment can be used as a cost-effective solution for purification of organically polluted industrial waste streams. This thesis presents results from microbiological investigations of several full-scale and lab-scale anaerobic wastewa

  10. Biohydrogen production from arabinose and glucose using extreme thermophilic anaerobic mixed cultures

    DEFF Research Database (Denmark)

    De Abreu, Angela Alexandra Valente; Karakashev, Dimitar Borisov; Angelidaki, Irini;

    2012-01-01

    differences in reactor performance were observed for arabinose and glucose organic loading rates (OLR) ranging from 4.3 to 7.1 kgCOD m-3 d-1. However, for an OLR of 14.2 kgCOD m-3 d-1, hydrogen production rate and hydrogen yield were higher in Rarab than in Rgluc (average hydrogen production rate of 3.2 and 2......Background Second generation hydrogen fermentation technologies using organic agricultural and forestry wastes are emerging. The efficient microbial fermentation of hexoses and pentoses resulting from the pretreatment of lingocellulosic materials is essential for the success of these processes....... Results Conversion of arabinose and glucose to hydrogen, by extreme thermophilic anaerobic mixed cultures was studied in continuous (70oC, pH 5.5) and batch (70oC, pH 5.5 and pH 7) assays. Two EGSB reactors, Rarab and Rgluc, were continuously fed with arabinose and glucose, respectively. No significant...

  11. Spirulina sp. LEB-18 culture using effluent from the anaerobic digestion

    Directory of Open Access Journals (Sweden)

    J. A. Borges

    2013-06-01

    Full Text Available The carbon source is the most expensive nutrient for Spirulina production; effluents from anaerobic digestion contain this nutrient in the form of HCO3-. The aim of this study was to assess the growth kinetics, composition and fatty acid profile of Spirulina sp. LEB-18 grown in standard Zarrouk medium (NaHCO3 16.8 g L-1 and in Zarrouk medium replaced with 20% (v/v effluent with reduced concentrations of NaHCO3 (5.3 and 2.8 g L-1. The use of effluent and lower concentrations of HCO3 was found to be an alternative to reduce the costs of Spirulina production, because there were no significant differences in growth parameters (µmax 0.324 - 0.354 d-1; Pmax 0.280 - 0.297 g L-1 d-1, in the different culture medium used. Lipids ranged between 4.9 and 5.0%; the media with effluent had higher levels of linoleic acid compared to the standard medium.

  12. Inhibitory effects of butyrate on biological hydrogen production with mixed anaerobic cultures.

    Science.gov (United States)

    Zheng, Xian-Jun; Yu, Han-Qing

    2005-01-01

    In this study batch experiments were conducted to investigate the inhibitory effects of butyrate addition on hydrogen production from glucose by using anaerobic mixed cultures. Experimental results showed that addition of butyrate at 4.18 and 6.27 g/l only slightly inhibited hydrogen production, and addition of butyrate at 8.36-12.54 g/l imposed a moderate inhibitory effect on hydrogen production. At addition of 25.08 g/l, butyrate had a strong inhibitory influence on substrate degradation and hydrogen production. The distribution of the volatile fatty acids produced from the acidogeneisis of glucose was significantly influenced by the addition of butyrate. The inhibition of butyrate addition on hydrogen production was described well by a non-competitive and non-linear inhibition model, with the maximum hydrogen production rate of 59.3 ml/g-SS/h, critical added butyrate concentration of 25.08 g/l, and inhibition degree of 0.323, respectively. The C(I,50) values (the butyrate concentration at which bioactivity is reduced by 50%) for hydrogen production rate and yield were estimated as 19.39 and 20.78 g/l of added butyrate, respectively.

  13. Benzene and ethylbenzene removal by denitrifying culture in a horizontal fixed bed anaerobic reactor

    Energy Technology Data Exchange (ETDEWEB)

    Gusmao, V.R.; Chinalia, F.A.; Sakamoto, I.K.; Varesche [Univ. de Sao Paulo (Brazil). Dept. de Hidraulica e Saneamento; Thiemann, O.H. [Univ. de Sao Paulo (Brazil). Inst. de Fisica de Sao Carlos

    2004-07-01

    Benzene, ethylbenzene, toluene, and xylene are toxic and are important constituents of gasoline and other petroleum fuels. These compounds are potential health hazards because of their high solubility and hence their ability to contaminate groundwater. Anaerobic immobilized biomass is a way of treating wastewater contaminated with the above compounds. The performance of a specially adapted biofilm is critical in the viability of this idea. In this investigation, an especially adapted biofilm was obtained using a denitrifying bacterial strain isolated from a slaughterhouse wastewater treatment plant. The strain was cultured in a liquid medium with added ethanol, nitrate, ethylbenzene, and benzene. To assess the viability of the strain for the purposes of degradation of ethylbenzene, and benzene two separate horizontal reactors were prepared with polyurethane foam in order to immobilize the biomass. Various concentrations of the two compounds were admitted. At high concentrations chemical oxygen demand decreased dramatically and benzene and ethylbenzene removal almost 100 per cent. DNA sequencing of the biofilm showed that Paracoccus versutus was the dominant species in the ethylbenzene reactor. 7 refs., 6 figs.

  14. Bio-Hydrogen Production from Pineapple Waste Extract by Anaerobic Mixed Cultures

    Directory of Open Access Journals (Sweden)

    Chakkrit Sreela-or

    2013-04-01

    Full Text Available A statistical experimental design was employed to optimize factors that affect the production of hydrogen from the glucose contained in pineapple waste extract by anaerobic mixed cultures. Results from Plackett-Burman design indicated that substrate concentration, initial pH and FeSO4 concentration had a statistically significant (p ≤ 0.05 influence on the hydrogen production potential (Ps and the specific hydrogen production rate (SHPR. The path of steepest ascent was undertaken to approach the optimal region of these three significant factors which was then optimized using response surface methodology (RSM with central composite design (CCD. The presence of a substrate concentration of 25.76 g-total sugar/L, initial pH of 5.56, and FeSO4 concentration of 0.81 g/L gave a maximum predicted Ps of 5489 mL H2/L, hydrogen yield of 1.83 mol H2/mol glucose, and SHPR of 77.31 mL H2/g-volatile suspended solid (VSS h. A verification experiment indicated highly reproducible results with the observed Ps and SHPR being only 1.13% and 1.14% different from the predicted values.

  15. Bacterial community analysis of cypermethrin enrichment cultures and bioremediation of cypermethrin contaminated soils.

    Science.gov (United States)

    Akbar, Shamsa; Sultan, Sikander; Kertesz, Michael

    2015-07-01

    Cypermethrin is widely used for insect control; however, its toxicity toward aquatic life requires its complete removal from contaminated areas where the natural degradation ability of microbes can be utilized. Agricultural soil with extensive history of CM application was used to prepare enrichment cultures using cypermethrin as sole carbon source for isolation of cypermethrin degrading bacteria and bacterial community analysis using PCR-DGGE of 16 S rRNA gene. DGGE analysis revealed that dominant members of CM enrichment culture were associated with α-proteobacteria followed by γ-proteobacteria, Firmicutes, and Actinobacteria. Three potential CM-degrading isolates identified as Ochrobactrum anthropi JCm1, Bacillus megaterium JCm2, and Rhodococcus sp. JCm5 degraded 86-100% of CM (100 mg L(-1) ) within 10 days. These isolates were also able to degrade other pyrethroids, carbofuran, and cypermethrin degradation products. Enzyme activity assays revealed that enzymes involved in CM-degradation were inducible and showed activity when strains were grown on cypermethrin. Degradation kinetics of cypermethrin (200 mg kg(-1)) in soils inoculated with isolates JCm1, JCm2, and JCm5 suggested time-dependent disappearance of cypermethrin with rate constants of 0.0516, 0.0425, and 0.0807 d(-1), respectively, following first order rate kinetics. The isolated bacterial strains were among dominant genera selected under CM enriched conditions and represent valuable candidates for in situ bioremediation of contaminated soils and waters.

  16. Production of cellulases and hemicellulases by an anaerobic mixed culture from lignocellulosic biomass.

    Science.gov (United States)

    Tabassum, R; Rajoka, M I; Malik, K A

    1990-03-01

    A comparison of different habitats, biogas plant, rumen fluid and sewage sludge, for cellulolytic organisms indicated sewage studge was the best source. Enrichment cultura gave a mixed culture which exhibited CMCase activity as well as extracellular Avicelase, xylanase, β-glucosidase, β-xylosidase activities and cell-bound β-glucosidase, and β-xylosidase production in a synthetic medium with eleven different cellulosic and lignocellulosic substrates. The activity of extracellular β-glucosidase and β-xylosidase production was significantly higher than endogenous activities. Hemicellulases were induced better than cellulases. The anzyme system was stable under aerobic conditions. Of the different lignocellulosic substrates, kallar grass was the best inducer of extracellular enzymes.

  17. Proteomic characterization of golgi membranes enriched from Arabidopsis suspension cell cultures

    DEFF Research Database (Denmark)

    Hansen, Sara Fasmer; Ebert, Berit; Rautengarten, Carsten;

    2016-01-01

    from an Arabidopsis cell suspension culture that can be used to investigate the proteome of this organelle. We also provide a useful workflow for the examination of proteomic data as the result of multiple analyses. Finally, we highlight a simple technique to validate the subcellular localization......The plant Golgi apparatus has a central role in the secretory pathway and is the principal site within the cell for the assembly and processing of macromolecules. The stacked membrane structure of the Golgi apparatus along with its interactions with the cytoskeleton and endoplasmic reticulum has...... historically made the isolation and purification of this organelle difficult. Density centrifugation has typically been used to enrich Golgi membranes from plant microsomal preparations, and aside from minor adaptations, the approach is still widely employed. Here we outline the enrichment of Golgi membranes...

  18. Detection of periodontopathogenic bacteria in pregnant women by traditional anaerobic culture method and by a commercial molecular genetic method.

    Science.gov (United States)

    Urbán, Edit; Terhes, Gabriella; Radnai, Márta; Gorzó, István; Nagy, Elisabeth

    2010-06-01

    To culture facultative and strict anaerobic bacteria is a well-established method for analyzing subgingival plaque samples. Micro-IDent and micro-IDent Plus (HAIN Lifescience GmbH, Nehren, Germany) tests are two commercially available rapid PCR-based methods for the identification and quantification of putative periodontopathogen bacteria. In this study, we compared these commercial PCR-based hybridization methods with conventional anaerobic culture technique. A total of 36 subgingival plaque samples were collected from periodontal pockets of pregnant women with chronic localized periodontitis. Aliquots of these samples were evaluated with species-specific probes provided by micro-IDent and micro-IDent Plus tests simultaneously, and from the same samples anaerobic and capnophylic bacteria were cultured on selective media. The overall agreement between both methods was excellent for Eubacterium nodatum, Tannerella forsythia and Porphyromonas gingivalis (97-92%), fair for Capnocytophaga sp, Eikenella corrodens, Actinobacillus actinomycetemcomitans, and Prevotella intermedia (91-89%) and poor for Fusobacterium nucleatum, Parvimonas micra (Micromonas micros), and Campylobacter rectus (86-78%). Discrepancies in the results may be explained by inability of culture method to distinguish between closely related taxa (e.i P. intermedia/Prevotella. nigrescens), and problems of keeping periodontopathogen bacteria viable, which is required for successful detection by standard culture method. Nucleic acid-based methods may replace cultivation method as frequently used methods in microbiological diagnosis of progressive periodontitis, thus micro-IDent and micro-IDent Plus tests can be recommended where culture of periodontopathogenic bacteria is not performed in routine microbiology laboratories to analyze subgingival plaque samples.

  19. Efficient anaerobic treatment of synthetic textile wastewater in a UASB reactor with granular sludge enriched with humic acids supported on alumina nanoparticles.

    Science.gov (United States)

    Cervantes, Francisco J; Gómez, Rafael; Alvarez, Luis H; Martinez, Claudia M; Hernandez-Montoya, Virginia

    2015-07-01

    A novel technique to co-immobilize humus-reducing microorganisms and humic substances (HS), supported on γ-Al2O3 nanoparticles (NP), by a granulation process in an upflow anaerobic sludge bed (UASB) reactor is reported in the present work. Larger granules (predominantly between 1 and 1.7 mm) were produced using NP coated with HS compared to those obtained with uncoated NP (mostly between 0.25 and 0.5 mm). The HS-enriched granular biomass was then tested for its capacity to achieve the reductive decolorization of the recalcitrant azo dye, reactive red 2 (RR2), in the same UASB reactor operated with a hydraulic residence time of 12 h and with glucose as electron donor. HS-enriched granules achieved higher decolorization and COD removal efficiencies, as compared to the control reactor operated in the absence of HS, in long term operation and applying high concentrations of RR2 (40-400 mg/L). This co-immobilizing technique could be attractive for its application in UASB reactors for the reductive biotransformation of several contaminants, such as nitroaromatics, poly-halogenated compounds, metalloids, among others.

  20. Improving the stability of thermophilic anaerobic digesters treating SS-OFMSW through enrichment with compost and leachate seeds

    KAUST Repository

    Ghanimeh, Sophia A.

    2013-03-01

    This paper examines the potential of improving the stability of thermophilic anaerobic digestion of source-sorted organic fraction of municipal solid waste (SS-OFMSW) by adding leachate and compost during inoculation. For this purpose, two stable thermophilic digesters, A (control) and B (with added leachate and compost), were subjected to a sustained substrate shock by doubling the organic loading rate for one week. Feeding was suspended then gradually resumed to reach the pre-shock loading rate (2. gVS/l/d). Digester A failed, exhibiting excessive increase in acetate and a corresponding decrease in pH and methane generation, and lower COD and solids removal efficiencies. In contrast, digester B was able to restore its functionality with 90% recovery of pre-shock methane generation rate at stable pH, lower hydrogen levels, and reduced VFAs and ammonia accumulation. © 2012 Elsevier Ltd.

  1. The importance of local events in enriching the cultural and tourism offer

    OpenAIRE

    Spasojević Bojana; Berić Dejan; Jovičić Ana

    2013-01-01

    In the municipality of Ruma twenty five events take place per year. Most of these events have local or regional character. The event "Christmas Street" is the youngest event which is being organized in Ruma, the first time was held in late 2011. The subject of this paper is to study this event that complements the existing tourism offer of Ruma as potential tourist destination of Vojvodina. The aim of this paper is to highlight the importance of this event in the cultural enrichment of ...

  2. Anaerobic biodegradation of benzene series compounds by mixed cultures based on optional electronic acceptors

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A series of batch experiments were performed using mixed bacterial consortia to investigate biodegradation performance of benzene,toluene,ethylbenzene and three xylene isomers (BTEX) under nitrate,sulfate and ferric iron reducing conditions.The results showed that toluene,ethylbenzeoe,m-xylene and o-xylene could be degraded independently by the mixed cultures coupled to nitrate,sulfate and ferric iron reduction.Under ferric iron reducing conditions the biodegradation of benzene and p-xylene could be occurred only in the presence of other alkylbenzenes.Alkylbenzenes can serve as the primary substrates to stimulate the transformation of benzene and p-xylene under anaerobic conditions.Benzene and p-xylene are more toxic than toluene and ethylbenzene,under the three terminal electron acceptors conditions,the degradation rates decreased with toluene > ethylbenzene > m-xylene > o-xylene > benzene > p-xylene.Nitrate was a more favorable electron acceptor compared to sulfate and ferric iron.The ratio between sulfate consumed and the loss of benzene,toluene,ethylbenzene,o-xylene,m-xylene,p-xylene was 4.44,4.51,4.42,4.32,4.37 and 4.23,respectively;the ratio between nitrate consumed and the loss of these substrates was 7.53,6.24,6.49,7.28,7.81,7.61,respectively;the ratio between the consumption of ferric iron and the loss of toluene,ethylbenzene,o-xylene,m-xylenewas 17.99,18.04,18.07,17.97,respectively.

  3. Use of Response Surface Methodology to Optimize Culture Conditions for Hydrogen Production by an Anaerobic Bacterial Strain from Soluble Starch

    Science.gov (United States)

    Kieu, Hoa Thi Quynh; Nguyen, Yen Thi; Dang, Yen Thi; Nguyen, Binh Thanh

    2016-05-01

    Biohydrogen is a clean source of energy that produces no harmful byproducts during combustion, being a potential sustainable energy carrier for the future. Therefore, biohydrogen produced by anaerobic bacteria via dark fermentation has attracted attention worldwide as a renewable energy source. However, the hydrogen production capability of these bacteria depends on major factors such as substrate, iron-containing hydrogenase, reduction agent, pH, and temperature. In this study, the response surface methodology (RSM) with central composite design (CCD) was employed to improve the hydrogen production by an anaerobic bacterial strain isolated from animal waste in Phu Linh, Soc Son, Vietnam (PL strain). The hydrogen production process was investigated as a function of three critical factors: soluble starch concentration (8 g L-1 to 12 g L-1), ferrous iron concentration (100 mg L-1 to 200 mg L-1), and l-cysteine concentration (300 mg L-1 to 500 mg L-1). RSM analysis showed that all three factors significantly influenced hydrogen production. Among them, the ferrous iron concentration presented the greatest influence. The optimum hydrogen concentration of 1030 mL L-1 medium was obtained with 10 g L-1 soluble starch, 150 mg L-1 ferrous iron, and 400 mg L-1 l-cysteine after 48 h of anaerobic fermentation. The hydrogen concentration produced by the PL strain was doubled after using RSM. The obtained results indicate that RSM with CCD can be used as a technique to optimize culture conditions for enhancement of hydrogen production by the selected anaerobic bacterial strain. Hydrogen production from low-cost organic substrates such as soluble starch using anaerobic fermentation methods may be one of the most promising approaches.

  4. Effect of cobalt on the Anaerobic Thermophilic Conversion of Methanol

    NARCIS (Netherlands)

    Paulo, P.L.; Jiang, B.; Cysneiros, D.; Stams, A.J.M.

    2004-01-01

    The importance of cobalt on the anaerobic conversion of methanol under thermophilic conditions was studied in three parallel lab-scale UASB-reactors and in cobalt-limited enriched cultures. Reactors R1, R2, and R3 were fed with methanol in a bicarbonate-buffered medium, supplied with iron and macron

  5. Biohydrogen production from desugared molasses (DM) using thermophilic mixed cultures immobilized on heat treated anaerobic sludge granules

    DEFF Research Database (Denmark)

    Kongjan, Prawit; O-Thong, Sompong; Angelidaki, Irini

    2011-01-01

    Hydrogen production from desugared molasses (DM) was investigated in both batch and continuous reactors using thermophilic mixed cultures enriched from digested manure by load shock (loading with DM concentration of 50.1 g-sugar/L) to suppress methanogens. H2 gas, free of methane, was produced du...

  6. Dissimilatory Reduction of Elemental Selenium to Selenide in Sediments and Anaerobic Cultures of Selenium Respiring Bacteria

    Science.gov (United States)

    Herbel, M. J.; Switzer-Blum, J.; Oremland, R. S.

    2001-12-01

    Selenium contaminated environments often contain elemental Se (Se0) in their sediments that originates from dissimilatory reduction of Se oxyanions. The forms of Se in sedimentary rocks similarly contain high proportions of Se0, but much of the Se is also in the form of metal selenides, Se-2. It is not clear if the occurrence of these selenides is due to microbial reduction of Se0, or some other biological or chemical process. In this investigation we examined the possibility that bacterial respiratory reduction of Se0 to Se-2 could explain the presence of the latter species in sedimentary rocks. We conducted incubations of anoxic sediment slurries amended with different forms of Se0. High levels of Se0 (mM) were added to San Francisco Bay sediments in order to enhance the detection of soluble HSe-, which was precipitated with Cu2+ then redissolved and quantified by ICP-MS. Concentrations of HSe- were highest in live samples amended with red amorphous Se0 formed by either microbial reduction of Se+4 ("biogenic Se0") or by chemical oxidation of H2Se(g) ("chem. Se0"); very little HSe- was formed in those amended with black crystalline Se0, indicating the general lack of reactivity of this allotrope. Controls poisoned with 10% formalin did not produce HSe- from additions of chem. Se0. Reduction of both forms of red amorphous Se0 to HSe- occurred vigorously in growing cultures of Bacillus selenitireducens, an anaerobic halophile previously isolated from sediments of Mono Lake, CA. Up to 73% and 68% of red amorphous, biogenic Se0 or chem. Se0, respectively, was reduced to HSe- during growth of B. selenitireducens, (incubation time ~ 200 hrs): oxidation of lactate to acetate as well as cell density increases indicated that a dissimilatory reduction pathway was likely. Reduction was most enhanced when cells were previously grown on elemental sulfur or Se+4. In contrast to the growth experiments, washed cell suspensions of B. selenitireducens exhibited no HSe- production

  7. Biohydrogen production from arabinose and glucose using extreme thermophilic anaerobic mixed cultures

    Directory of Open Access Journals (Sweden)

    Abreu Angela A

    2012-02-01

    Full Text Available Abstract Background Second generation hydrogen fermentation technologies using organic agricultural and forestry wastes are emerging. The efficient microbial fermentation of hexoses and pentoses resulting from the pretreatment of lingocellulosic materials is essential for the success of these processes. Results Conversion of arabinose and glucose to hydrogen, by extreme thermophilic, anaerobic, mixed cultures was studied in continuous (70°C, pH 5.5 and batch (70°C, pH 5.5 and pH 7 assays. Two expanded granular sludge bed (EGSB reactors, Rarab and Rgluc, were continuously fed with arabinose and glucose, respectively. No significant differences in reactor performance were observed for arabinose and glucose organic loading rates (OLR ranging from 4.3 to 7.1 kgCOD m-3 d-1. However, for an OLR of 14.2 kgCOD m-3 d-1, hydrogen production rate and hydrogen yield were higher in Rarab than in Rgluc (average hydrogen production rate of 3.2 and 2.0 LH2 L-1 d-1 and hydrogen yield of 1.10 and 0.75 molH2 mol-1substrate for Rarab and Rgluc, respectively. Lower hydrogen production in Rgluc was associated with higher lactate production. Denaturing gradient gel electrophoresis (DGGE results revealed no significant difference on the bacterial community composition between operational periods and between the reactors. Increased hydrogen production was observed in batch experiments when hydrogen partial pressure was kept low, both with arabinose and glucose as substrate. Sugars were completely consumed and hydrogen production stimulated (62% higher when pH 7 was used instead of pH 5.5. Conclusions Continuous hydrogen production rate from arabinose was significantly higher than from glucose, when higher organic loading rate was used. The effect of hydrogen partial pressure on hydrogen production from glucose in batch mode was related to the extent of sugar utilization and not to the efficiency of substrate conversion to hydrogen. Furthermore, at pH 7.0, sugars

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

    Science.gov (United States)

    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

  9. Identification of novel glycosyl hydrolases with cellulolytic activity against crystalline cellulose from metagenomic libraries constructed from bacterial enrichment cultures

    OpenAIRE

    Mori, Toshio; Kamei, Ichiro; Hirai, Hirofumi; Kondo, Ryuichiro

    2014-01-01

    To obtain cellulases that are capable of degrading crystalline cellulose and cedar wood, metagenomic libraries were constructed from raw soil sample which was covered to pile of cedar wood sawdust or from its enrichment cultures. The efficiency of screening of metagenomic library was improved more than 3 times by repeating enrichment cultivation using crystalline cellulose as a carbon source, compared with the library constructed from raw soil. Four cellulase genes were obtained from the meta...

  10. Biogeochemical insights into microbe-mineral-fluid interactions in hydrothermal chimneys using enrichment culture.

    Science.gov (United States)

    Callac, Nolwenn; Rouxel, Olivier; Lesongeur, Françoise; Liorzou, Céline; Bollinger, Claire; Pignet, Patricia; Chéron, Sandrine; Fouquet, Yves; Rommevaux-Jestin, Céline; Godfroy, Anne

    2015-05-01

    Active hydrothermal chimneys host diverse microbial communities exhibiting various metabolisms including those involved in various biogeochemical cycles. To investigate microbe-mineral-fluid interactions in hydrothermal chimney and the driver of microbial diversity, a cultural approach using a gas-lift bioreactor was chosen. An enrichment culture was performed using crushed active chimney sample as inoculum and diluted hydrothermal fluid from the same vent as culture medium. Daily sampling provided time-series access to active microbial diversity and medium composition. Active archaeal and bacterial communities consisted mainly of sulfur, sulfate and iron reducers and hydrogen oxidizers with the detection of Thermococcus, Archaeoglobus, Geoglobus, Sulfurimonas and Thermotoga sequences. The simultaneous presence of active Geoglobus sp. and Archaeoglobus sp. argues against competition for available carbon sources and electron donors between sulfate and iron reducers at high temperature. This approach allowed the cultivation of microbial populations that were under-represented in the initial environmental sample. The microbial communities are heterogeneously distributed within the gas-lift bioreactor; it is unlikely that bulk mineralogy or fluid chemistry is the drivers of microbial community structure. Instead, we propose that micro-environmental niche characteristics, created by the interaction between the mineral grains and the fluid chemistry, are the main drivers of microbial diversity in natural systems.

  11. Microbial communities involved in anaerobic degradation of unsaturated or saturated long chain fatty acids

    OpenAIRE

    Sousa, D.Z.; Pereira, M.A.; Stams, A.J.M.; Alves, M. M.; Smidt, H.

    2007-01-01

    Anaerobic long-chain fatty acid (LCFA)-degrading bacteria were identified by combining selective enrichment studies with molecular approaches. Two distinct enrichment cultures growing on unsaturated and saturated LCFAs were obtained by successive transfers in medium containing oleate and palmitate, respectively, as the sole carbon and energy sources. Changes in the microbial composition during enrichment were analyzed by denaturing gradient gel electrophoresis (DGGE) profiling of PCR...

  12. Selective enrichment and production of highly urease active bacteria by non-sterile (open) chemostat culture.

    Science.gov (United States)

    Cheng, Liang; Cord-Ruwisch, Ralf

    2013-10-01

    In general, bioprocesses can be subdivided into naturally occurring processes, not requiring sterility (e.g., beer brewing, wine making, lactic acid fermentation, or biogas digestion) and other processes (e.g., the production of enzymes and antibiotics) that typically require a high level of sterility to avoid contaminant microbes overgrowing the production strain. The current paper describes the sustainable, non-sterile production of an industrial enzyme using activated sludge as inoculum. By using selective conditions (high pH, high ammonia concentration, and presence of urea) for the target bacterium, highly active ureolytic bacteria, physiologically resembling Sporosarcina pasteurii were reproducibly enriched and then continuously produced via chemostat operation of the bioreactor. When using a pH of 10 and about 0.2 M urea in a yeast extract-based medium, ureolytic bacteria developed under aerobic chemostat operation at hydraulic retention times of about 10 h with urease levels of about 60 μmol min⁻¹ ml⁻¹ culture. For cost minimization at an industrial scale the costly protein-rich yeast extract medium could be replaced by commercial milk powder or by lysed activated sludge. Glutamate, molasses, or glucose-based media did not result in the enrichment of ureolytic bacteria by the chemostat. The concentration of intracellular urease was sufficiently high such that the produced raw effluent from the reactor could be used directly for biocementation in the field.

  13. Fermentative bio-hydrogen production from cellulose by cow dung compost enriched cultures

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Nan-Qi; Xu, Ji-Fei; Gao, Ling-Fang; Xin, Liang; Qiu, Jie; Su, Dong-Xia [State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090 (China)

    2010-04-15

    The performance of hydrogen production from cellulose by the cow dung compost enriched continuously in defined medium containing cellulose was investigated. In the initial experiments, batch-fermentation was carried out to observe the effects of different substrate concentration conditions on the rate of cellulose-degrading, growth of bacteria and the capability of hydrogen-producing from cellulose. The result showed that the cellulose degradation decreased from 55% at 5 g/l to 22% at 30 g/l. The maximum cumulative hydrogen production and the rate of hydrogen production first increased from 828 ml/l at 5 g/l to 1251 ml/l at 10 g/l then remained constant beyond 10 g/l. The maximum hydrogen production potential, the rate of hydrogen production and the yield of hydrogen was 1525 ml/l, 33 ml/l.h, and 272 ml/g-cellulose (2.09 mol/mol-hexose) was obtained at substrate concentration 10 g/l, the hydrogen concentration in biogas was 47-50%(v/v) and there was no methane observed. During the conversion of cellulose into hydrogen, acetate and butyrate were main liquid end-products in the metabolism of hydrogen fermentation. These results proposed that cow dung compost enriched cultures were ideal microflora for hydrogen production from cellulose. (author)

  14. Selective enrichment of hepatoeytes from mouse embryonic stem cells with a culture system containing cholestatic serum

    Institute of Scientific and Technical Information of China (English)

    Jun MIN; Er-wei SONG; Ji-sheng CHEN; Chang-zhen SHANG; Ya-jin CHEN; Lei ZHANG; Lu LIU; Xiao-geng DENG; Mei YANG; Dong-ping CHEN; Jun CAO

    2007-01-01

    Aim: There is increasing evidence indicating that embryonic stem (ES) cells are capable of differentiating into hepatocyte-like cells in vitro. However, it is neces- sary to improve the differentiation efficiency so as to promote the clinical application. Here, we report an efficient culture system to support hepatocyte differentiation from ES cells by utilizing cholestatic serum. Methods: One week after the induction of El4 mouse ES cells into hepatocytes with sodium butyrate, cholestatic serum was added into the culture system at various concentrations and hepatocyte-like cells were induced to proliferate. The morphological and phenotypic markers of hepatocytes were characterized using light microscopy, immunocytochemistry, and RT-PCR, respectively. The function of glycogen stor- age of the differentiated cells was detected by Periodic acid-Schiff (PAS) reaction, and the ratio of hepatic differentiation was determined by counting the albumin and PAS-positive cells. Results: In the presence of conditional selective medium containing cholestatic serum, numerous epithelial cells resembling hepatocytes were observed. The RT-PCR analysis showed that undifferentiated ES cells did not express any hepatic-specific markers; however, in the presence of sodium butyrate and conditional selective medium containing cholestatic serum, hepatic differentiation markers were detected. Immunofluorescence staining showed that those ES-derived hepatocytes were α-fetoprotein, albumin, and cytokeratin 18 positive, with the ability of storing glycogen. Further determination of the hepatic differentiation ratio showed that the application of cholestatic serum efficiently enriched ES-derived hepatocyte-like cells by inducing lineage differentiation and enhancing lineage proliferation. Conclusion: The conditional selective medium containing cholestatic serum is optimal to selectively enrich hepatocyte-like cells from mixed differentiated ES cells, which may provide a novel method to

  15. Hydrogenotrophic culture enrichment reveals rumen Lachnospiraceae and Ruminococcaceae acetogens and hydrogen-responsive Bacteroidetes from pasture-fed cattle.

    Science.gov (United States)

    Gagen, Emma J; Padmanabha, Jagadish; Denman, Stuart E; McSweeney, Christopher S

    2015-07-01

    Molecular information suggests that there is a broad diversity of acetogens in the rumen, distinct from any currently isolated acetogens. We combined molecular analysis with enrichment culture techniques to investigate this diversity further. Methane-inhibited, hydrogenotrophic enrichment cultures produced acetate as the dominant end product. Acetyl-CoA synthase gene analysis revealed putative acetogens in the cultures affiliated with the Lachnospiraceae and Ruminococcaceae as has been found in other rumen studies. No formyltetrahydrofolate synthetase genes affiliating with acetogens or with 'homoacetogen similarity' scores >90% were identified. To further investigate the hydrogenotrophic populations in these cultures and link functional gene information with 16S rRNA gene identity, cultures were subcultured quickly, twice, through medium without exogenous hydrogen, followed by incubation without exogenous hydrogen. Comparison of cultures lacking hydrogen and their parent cultures revealed novel Lachnospiraceae and Ruminococcaceae that diminished in the absence of hydrogen, supporting the hypothesis that they were likely the predominant acetogens in the enrichments. Interestingly, a range of Bacteroidetes rrs sequences that demonstrated <86% identity to any named isolate also diminished in cultures lacking hydrogen. Acetogens or sulphate reducers from the Bacteroidetes have not been reported previously; therefore this observation requires further investigation.

  16. Hydrogenotrophic culture enrichment reveals rumen Lachnospiraceae and Ruminococcaceae acetogens and hydrogen-responsive Bacteroidetes from pasture-fed cattle.

    Science.gov (United States)

    Gagen, Emma J; Padmanabha, Jagadish; Denman, Stuart E; McSweeney, Christopher S

    2015-07-01

    Molecular information suggests that there is a broad diversity of acetogens in the rumen, distinct from any currently isolated acetogens. We combined molecular analysis with enrichment culture techniques to investigate this diversity further. Methane-inhibited, hydrogenotrophic enrichment cultures produced acetate as the dominant end product. Acetyl-CoA synthase gene analysis revealed putative acetogens in the cultures affiliated with the Lachnospiraceae and Ruminococcaceae as has been found in other rumen studies. No formyltetrahydrofolate synthetase genes affiliating with acetogens or with 'homoacetogen similarity' scores >90% were identified. To further investigate the hydrogenotrophic populations in these cultures and link functional gene information with 16S rRNA gene identity, cultures were subcultured quickly, twice, through medium without exogenous hydrogen, followed by incubation without exogenous hydrogen. Comparison of cultures lacking hydrogen and their parent cultures revealed novel Lachnospiraceae and Ruminococcaceae that diminished in the absence of hydrogen, supporting the hypothesis that they were likely the predominant acetogens in the enrichments. Interestingly, a range of Bacteroidetes rrs sequences that demonstrated <86% identity to any named isolate also diminished in cultures lacking hydrogen. Acetogens or sulphate reducers from the Bacteroidetes have not been reported previously; therefore this observation requires further investigation. PMID:26109360

  17. ANAMMOX process start up and stabilization with an anaerobic seed in Anaerobic Membrane Bioreactor (AnMBR).

    Science.gov (United States)

    Suneethi, S; Joseph, Kurian

    2011-10-01

    ANaerobic AMMonium OXidation (ANAMMOX) process, an advanced biological nitrogen removal alternative to traditional nitrification--denitrification removes ammonia using nitrite as the electron acceptor without oxygen. The feasibility of enriching anammox bacteria from anaerobic seed culture to start up an Anaerobic Membrane Bioreactor (AnMBR) for N-removal is reported in this paper. The Anammox activity was established in the AnMBR with anaerobic digester seed culture from a Sewage Treatment Plant in batch mode with recirculation followed by semi continuous process and continuous modes of operation. The AnMBR performance under varying Nitrogen Loading Rates (NLR) and HRTs is reported for a year, in terms of nitrogen transformations to ammoniacal nitrogen, nitrite and nitrate along with hydrazine and hydroxylamine. Interestingly ANAMMOX process was evident from simultaneous Amm-N and nitrite reduction, consistent nitrate production, hydrazine and hydroxylamine presence, notable organic load reduction and bicarbonate consumption. PMID:21775136

  18. In Search of functionality-diversity relationships in anaerobic mixed culture fermentations

    International Nuclear Information System (INIS)

    Based on the work described in this paper we will postulate that in environmental ecosystems with a weak selective pressure no clear relationship exists between the ecosystem functionality and the microbial diversity and microbial composition. In the past years we have been investigating the anaerobic fermentation of glucose, xylose, and glycerol, and mixtures of these substrates in continuously stirred tank reactors (CSTR) inoculated with an activated sludge characterized by a very rich microbial diversity. (Author)

  19. Therapy of Chronic Cardiosclerosis in WAG Rats Using Cultures of Cardiovascular Cells Enriched with Cardiac Stem Cell.

    Science.gov (United States)

    Chepeleva, E V; Pavlova, S V; Malakhova, A A; Milevskaya, E A; Rusakova, Ya L; Podkhvatilina, N A; Sergeevichev, D S; Pokushalov, E A; Karaskov, A M; Sukhikh, G T; Zakiyan, S M

    2015-11-01

    We developed a protocol for preparing cardiac cell culture from rat heart enriched with regional stem cells based on clonogenic properties and proliferation in culture in a medium with low serum content. Experiments on WAG rats with experimental ischemic myocardial damage showed that implantation of autologous regional stem cells into the left ventricle reduced the volume of cicatricial tissue, promoted angiogenesis in the damaged zone, and prevented the risk of heart failure development.

  20. Influence of an aerobic fungus grown on solid culture on ruminal degradability and on a mixture culture of anaerobic cellulolytic bacteria.

    Science.gov (United States)

    Hernández-Díaz, R; Pimentel-González, D J; Figueira, A C; Viniegra-González, G; Campos-Montiel, R G

    2010-06-01

    In this work, the effect of a solid fungal culture of Aspergillus niger (An) grown on coffee pulp on the in situ ruminal degradability (RD) of corn stover was evaluated. In addition, the effect of its extracts on the in vitro dry matter disappearance (IVDMD) and on a mixed culture of anaerobic cellulolytic bacteria (MCACB) was also investigated. The solid ferment was a crude culture of An, grown on coffee pulp. Regarding in situ RD, a significant difference (p < 0.05) was found between treatment with 200 g/day of the solid culture and control (no solid culture added) on dry matter, crude protein and neutral detergent fibre on RD. All the water extracts (pH 4, 7 and 10) enhanced IVDMD and stimulated the cellulolytic activity on a MCACB. Ultrafiltration results showed that active compounds with a molecular weight lower than 30 kDa were responsible for the effect on MCACB. Such results suggest that the effects of the solid An culture in RD are related to the presence of water soluble compounds having a molecular weight lower than 30 kDa.

  1. High molecular weight dissolved organic matter enrichment selects for methylotrophs in dilution to extinction cultures.

    Science.gov (United States)

    Sosa, Oscar A; Gifford, Scott M; Repeta, Daniel J; DeLong, Edward F

    2015-12-01

    The role of bacterioplankton in the cycling of marine dissolved organic matter (DOM) is central to the carbon and energy balance in the ocean, yet there are few model organisms available to investigate the genes, metabolic pathways, and biochemical mechanisms involved in the degradation of this globally important carbon pool. To obtain microbial isolates capable of degrading semi-labile DOM for growth, we conducted dilution to extinction cultivation experiments using seawater enriched with high molecular weight (HMW) DOM. In total, 93 isolates were obtained. Amendments using HMW DOM to increase the dissolved organic carbon concentration 4x (280 μM) or 10x (700 μM) the ocean surface water concentrations yielded positive growth in 4-6% of replicate dilutions, whereas <1% scored positive for growth in non-DOM-amended controls. The majority (71%) of isolates displayed a distinct increase in cell yields when grown in increasing concentrations of HMW DOM. Whole-genome sequencing was used to screen the culture collection for purity and to determine the phylogenetic identity of the isolates. Eleven percent of the isolates belonged to the gammaproteobacteria including Alteromonadales (the SAR92 clade) and Vibrio. Surprisingly, 85% of isolates belonged to the methylotrophic OM43 clade of betaproteobacteria, bacteria thought to metabolically specialize in degrading C1 compounds. Growth of these isolates on methanol confirmed their methylotrophic phenotype. Our results indicate that dilution to extinction cultivation enriched with natural sources of organic substrates has a potential to reveal the previously unsuspected relationships between naturally occurring organic nutrients and the microorganisms that consume them.

  2. Stable acetate production in extreme-thermophilic (70ºC) mixed culture fermentation by selective enrichment of hydrogenotrophic methanogens

    NARCIS (Netherlands)

    Zhang, F.; Zhang, Y.; Ding, J.; Dai, K.; Van Loosdrecht, M.C.M.; Zeng, R.J.

    2014-01-01

    The control of metabolite production is difficult in mixed culture fermentation. This is particularly related to hydrogen inhibition. In this work, hydrogenotrophic methanogens were selectively enriched to reduce the hydrogen partial pressure and to realize efficient acetate production in extreme-th

  3. Transcriptional monitoring of steady state and effects of anaerobic phases in chemostat cultures of the filamentous fungus Trichoderma reesei

    Directory of Open Access Journals (Sweden)

    Penttilä Merja

    2006-10-01

    Full Text Available Abstract Background Chemostat cultures are commonly used in production of cellular material for systems-wide biological studies. We have used the novel TRAC (transcript analysis with aid of affinity capture method to study expression stability of approximately 30 process relevant marker genes in chemostat cultures of the filamentous fungus Trichoderma reesei and its transformant expressing laccase from Melanocarpus albomyces. Transcriptional responses caused by transient oxygen deprivations and production of foreign protein were also studied in T. reesei by TRAC. Results In cultures with good steady states, the expression of the marker genes varied less than 20% on average between sequential samples for at least 5 or 6 residence times. However, in a number of T. reesei cultures continuous flow did not result in a good steady state. Perturbations to the steady state were always evident at the transcriptional level, even when they were not measurable as changes in biomass or product concentrations. Both unintentional and intentional perturbations of the steady state demonstrated that a number of genes involved in growth, protein production and secretion are sensitive markers for culture disturbances. Exposure to anaerobic conditions caused strong responses at the level of gene expression, but surprisingly the cultures could regain their previous steady state quickly, even after 3 h O2 depletion. The main effect of producing M. albomyces laccase was down-regulation of the native cellulases compared with the host strain. Conclusion This study demonstrates the usefulness of transcriptional analysis by TRAC in ensuring the quality of chemostat cultures prior to costly and laborious genome-wide analysis. In addition TRAC was shown to be an efficient tool in studying gene expression dynamics in transient conditions.

  4. Anaerobic Degradation of Chlorinated Hydrocarbons in Groundwater Aquifers or "Chlorinated Hydrocarbon Degradation"

    OpenAIRE

    Nielsen, R. Brent; Jay D Keasling

    1997-01-01

    Groundwater contamination by chlorinated hydrocarbons, such as tetrachloroethene (PCE) or trichloroethene (TCE), is a major concern throughout the United States. A developing strategy for the remediation of PCE and TCE contaminated aquifers is anaerobic biodegradation. From a TCE contaminated groundwater site, microorganisms were enriched with the ability to anaerobically convert PCE and TCE completely to ethene. Kinetic studies performed with this culture showed that degradation of PCE, TCE...

  5. Timeline of bio-hydrogen production by anaerobic digestion of biomass

    OpenAIRE

    Bernadette E. TELEKY; Mugur C. BĂLAN; Nikolausz, Marcell

    2015-01-01

    Anaerobic digestion of biomass is a process capable to produce biohydrogen, a clean source of alternative energy. Lignocellulosic biomass from agricultural waste is considered a renewable energy source; therefore its utilization also contributes to the reduction of water, soil and air pollution. The study consists in five consecutive experiments designed to utilize anaerobic bacterial enrichment cultures originating from the Hungarian Lake, Hévíz. Wheat straw was used as com...

  6. Do furanic and phenolic compounds of lignocellulosic and algae biomass hydrolyzate inhibit anaerobic mixed cultures? A comprehensive review.

    Science.gov (United States)

    Monlau, F; Sambusiti, C; Barakat, A; Quéméneur, M; Trably, E; Steyer, J-P; Carrère, H

    2014-01-01

    Nowadays there is a growing interest on the use of both lignocellulosic and algae biomass to produce biofuels (i.e. biohydrogen, ethanol and methane), as future alternatives to fossil fuels. In this purpose, thermal and thermo-chemical pretreatments have been widely investigated to overcome the natural physico-chemical barriers of such biomass and to enhance biofuel production from lignocellulosic residues and, more recently, marine biomass (i.e. macro and microalgae). However, the pretreatment technologies lead not only to the conversion of carbohydrate polymers (ie cellulose, hemicelluloses, starch, agar) to soluble monomeric sugar (ie glucose, xylose, arabinose, galactose), but also the generation of various by-products (i.e. furfural and 5-HMF). In the case of lignocellulosic residues, part of the lignin can also be degraded in lignin derived by-products, mainly composed of phenolic compounds. Although the negative impact of such by-products on ethanol production has been widely described in literature, studies on their impact on biohydrogen and methane production operated with mixed cultures are still very limited. This review aims to summarise and discuss literature data on the impact of pre-treatment by-products on H2-producing dark fermentation and anaerobic digestion processes when using mixed cultures as inoculum. As a summary, furanic (5-HMF, furfural) and phenolic compounds were found to be stronger inhibitors of the microbial dark fermentation than the full anaerobic digestion process. Such observations can be explained by differences in process parameters: anaerobic digestion is performed with more complex mixed cultures, lower substrate/inoculum and by-products/inoculum ratios and longer batch incubation times than dark fermentation. Finally, it has been reported that, during dark fermentation process, the presence of by-products could lead to a metabolic shift from H2-producing pathways (i.e. acetate and butyrate) to non-H2-producing pathways (i

  7. Fermentative Hydrogen Production by Pure Culture with a New H2-producing Anaerobe

    Institute of Scientific and Technical Information of China (English)

    LI Yong-feng; REN Nan-qi; YANG Chuan-ping; XU Jing-li

    2006-01-01

    As a new clean energy source, the utilization and demand for hydrogen fuel are rapidly increasing. The integrated process of wastewater treatment of DESAR and energy recovery was developed in the studies. A new hydrogen anaerobe was isolated from the activated sludge. The optimal glucose concentration and the optimal initial pH were 12.0 g/L and 5. 5 respectively. The optimum C/N of the growth and hydrogen production in Rennanqilyf3 was (3.0 ~3.5): 1. The integrated process between DESAR system and biohydrogen production will be an important progress on energy recovery of DESAR system.

  8. Biodegradation of Various Aromatic Compounds by Enriched Bacterial Cultures: Part A-Monocyclic and Polycyclic Aromatic Hydrocarbons.

    Science.gov (United States)

    Oberoi, Akashdeep Singh; Philip, Ligy; Bhallamudi, S Murty

    2015-08-01

    Present study focused on the screening of bacterial consortium for biodegradation of monocyclic aromatic hydrocarbon (MAH) and polycyclic aromatic hydrocarbons (PAHs). Target compounds in the present study were naphthalene, acenaphthene, phenanthrene (PAHs), and benzene (MAH). Microbial consortia enriched with the above target compounds were used in screening experiments. Naphthalene-enriched consortium was found to be the most efficient consortium, based on its substrate degradation rate and its ability to degrade other aromatic pollutants with significantly high efficiency. Substrate degradation rate with naphthalene-enriched culture followed the order benzene > naphthalene > acenaphthene > phenanthrene. Chryseobacterium and Rhodobacter were discerned as the predominant species in naphthalene-enriched culture. They are closely associated to the type strain Chryseobacterium arthrosphaerae and Rhodobacter maris, respectively. Single substrate biodegradation studies with naphthalene (PAH) and benzene (MAH) were carried out using naphthalene-enriched microbial consortium (NAPH). Phenol and 2-hydroxybenzaldehyde were identified as the predominant intermediates during benzene and naphthalene degradation, respectively. Biodegradation of toluene, ethyl benzene, xylene, phenol, and indole by NAPH was also investigated. Monod inhibition model was able to simulate biodegradation kinetics for benzene, whereas multiple substrate biodegradation model was able to simulate biodegradation kinetics for naphthalene.

  9. Survey of Naegleria from Taiwan recreational waters using culture enrichment combined with PCR.

    Science.gov (United States)

    Huang, Shih-Wei; Hsu, Bing-Mu

    2011-08-01

    Naegleria is a free-living amoeba. Pathogenic Naegleria may pose a health risk to people who come in contact with recreational waters. Here, we used Naegleria culture enrichment with PCR to identify the Naegleria species and investigated the distribution of Naegleria spp. in recreational waters including spring water, stream water and raw domestic water in central and southern Taiwan. In this study, Naegleria spp. were detected in 19 (17.8%) of the water samples. The occurrence of Naegleria in raw domestic water was 28.6%, higher than in stream water (14.7%) and in spring water (6.5%). The most frequently identified species exhibiting the closest phylogenetic relationships to the isolates were N. australiensis (n=4) and N. canariensis (n=4), followed by N. clarki (n=3) and N. philippinensis (n=3); N. americana (n=2). N. lovaniensis, N. dobsoni, and N. gruberi were each detected once. The pathogenic species N. fowleri was not detected, probably due to the low incubation temperature; however, the isolates exhibiting the closest phylogenetic relationships to the pathogenic species in mice of PAM, N. australiensis and N. philippinensis, were found. Results of this survey suggest the distribution of Naegleria spp. excluding N. fowleri in recreational waters. It should be considered a potential threat for health associated with human activities in recreational waters.

  10. The role of acid incubation in rapid immobilization of hydrogen-producing culture in anaerobic upflow column reactors

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhen-Peng; Tay, Joo-Hwa [School of Civil and Environmental Engineering, Nanyang Technological University (Singapore); Institute of Environmental Science and Engineering, Nanyang Technological University (Singapore); Show, Kuan-Yeow [Faculty of Science, Engineering and Technology, University Tunku Abdul Rahman, 31900 Kampar, Perak (Malaysia); Liang, David Tee [Institute of Environmental Science and Engineering, Nanyang Technological University (Singapore); Lee, Duu-Jong [Department of Chemical Engineering, National Taiwan University, Taipei 10617 (China); Su, Ay [Department of Mechanical Engineering, Fuel Cell Center, Yuan-Ze University, Taoyuan 320 (China)

    2008-10-15

    An approach of acidification was examined on formation of hydrogen-producing granules and biofilms in upflow column-shaped reactors. The reactors were fed with synthetic glucose wastewater and operated at 37 C and pH 5.5. The acclimated anaerobic culture was inoculated in four reactors designated R1, R2, R3 and R4, with R3 and R4 filled with granular activated carbon as support medium. To unveil the roles of acidification, microbial culture in R2 and R3 was subject to an acid incubation for 24 h by shifting the culture pH from 5.5 to 2.0. The experimental results suggested that the acidification substantially accelerated microbial granulation, but not biofilm formation. Microbial activities were inhibited by the acid incubation for about 78 h, resulting in the retarded formation of biofilms of the acidified culture. Reducing culture pH resulted in improvement in cell surface physicochemical properties favoring microbial adhesion and immobilization. Zeta potential increased from -25.3 mV to 11.9 mV, hydrophobicity in terms of contact angle improved from 31 to 38 and production of extracellular polymers increased from 66 mg/g-VSS to 136 mg/g-VSS. As a result of the formation of granules and biofilms, high hydrogen production rates of 6.98 and 7.49 L/L h were achieved in granule-based and biofilm-based reactors, respectively. It is concluded that acid incubation is an efficient means to initiate the rapid formation of granules by regulating the surface characteristics of microbial culture. The use of support media as starting nuclei may result in rapid formation of biofilms without the acidification. (author)

  11. Fate of extracellular polymeric substances of anaerobically digested sewage sludge during pre-dewatering conditioning with Acidithiobacillus ferrooxidans culture.

    Science.gov (United States)

    Murugesan, Kumarasamy; Ravindran, Balasubramani; Selvam, Ammaiyappan; Kurade, Mayur B; Yu, Shuk-Man; Wong, Jonathan W C

    2016-10-01

    This study investigated the fate of extracellular polymeric substances (EPS) of anaerobically digested saline sewage sludge during its preconditioning. Sludge was conditioned with Acidithiobacillus ferrooxidans (AF) culture for 24h in the presence and absence of Fe(2+) as an energy substrate. pH decreased from 7.24 to 3.12 during sludge conditioning process. The capillary suction time (CST) of conditioned sludge significantly decreased to 94% as compared with control within 4h of conditioning with or without Fe(2+), indicating a significant (P<0.001) improvement in sludge dewaterability. A noticeable decrease in extractable EPS was observed in conditioned sludge. The EPS contents showed a significant negative correlation with dewaterability of sludge (P<0.05). The results suggest that bioacidification treatment using A. ferrooxidans effectively improved sludge dewaterability through modification of sludge EPS. PMID:27040507

  12. Anaerobes beyond anaerobic digestion

    OpenAIRE

    Sousa, D. Z.; Pereira, M A; Alves, M.M.

    2009-01-01

    Anaerobic microorganisms are widespread in nature. Sediments, gastrointestinal tracks, volcanic vents, geothermal sources are examples of habitats where anaerobic metabolism prevail, in some cases at extreme temperature, pH and pressure conditions. In such microbial ecosystems waste of some is food for others in a true integrated structure. Anaerobic microorganisms are able to use a wide variety of organic and inorganic compounds. Recalcitrant compounds, such as hydrocarbons, a...

  13. Dehalobacter restrictus gen. nov. and sp. nov., a strictly anaerobic bacterium that reductively dechlorinates tetra- and trichloroethene in an anaerobic respiration

    NARCIS (Netherlands)

    Holliger, C; Hahn, D; Harmsen, H; Ludwig, W; Schumacher, W; Tindall, B; Vazquez, F; Weiss, N; Zehnder, AJB

    1998-01-01

    The highly enriched anaerobic bacterium that couples the reductive dechlorination of tetrachloroethene to growth, previously referred to as PER-K23, was obtained in pure culture and characterized. The bacterium, which does not form spores, is a small, gram-negative rod with one lateral flagellum. It

  14. Passive markers as a low-cost method of enriching cultural visits on user’s demand

    Directory of Open Access Journals (Sweden)

    Anestis Koutsoudis

    2014-01-01

    Full Text Available The idea of enriching a cultural heritage visitor’s experience by employing mobile devices such as smartphones and tablets is an active research domain. This is mainly due to the worldwide user penetration of such devices along with their continuous hardware performance enhancement. This work presents the experience and feedback gained by one year of operation of an experimental information system that aims in enhancing the experience of a visitor on his/her demand. The evaluated system is based on the use case-scenario where the a mobile device is used to capture and decode passive markers (such as QR-codes that are located on facades of selected important buildings in the old town of Xanthi, Greece, in order to enrich the visitor’s experience through a broad context of historical and architectural information delivered over the Web.   Keywords: On-demand information, Passive marker, QR-code, Smartphone, Visit enrichment.

  15. Bacterial community analysis in chlorpyrifos enrichment cultures via DGGE and use of bacterial consortium for CP biodegradation.

    Science.gov (United States)

    Akbar, Shamsa; Sultan, Sikander; Kertesz, Michael

    2014-10-01

    The organophosphate pesticide chlorpyrifos (CP) has been used extensively since the 1960s for insect control. However, its toxic effects on mammals and persistence in environment necessitate its removal from contaminated sites, biodegradation studies of CP-degrading microbes are therefore of immense importance. Samples from a Pakistani agricultural soil with an extensive history of CP application were used to prepare enrichment cultures using CP as sole carbon source for bacterial community analysis and isolation of CP metabolizing bacteria. Bacterial community analysis (denaturing gradient gel electrophoresis) revealed that the dominant genera enriched under these conditions were Pseudomonas, Acinetobacter and Stenotrophomonas, along with lower numbers of Sphingomonas, Agrobacterium and Burkholderia. Furthermore, it revealed that members of Bacteroidetes, Firmicutes, α- and γ-Proteobacteria and Actinobacteria were present at initial steps of enrichment whereas β-Proteobacteria appeared in later steps and only Proteobacteria were selected by enrichment culturing. However, when CP-degrading strains were isolated from this enrichment culture, the most active organisms were strains of Acinetobacter calcoaceticus, Pseudomonas mendocina and Pseudomonas aeruginosa. These strains degraded 6-7.4 mg L(-1) day(-1) of CP when cultivated in mineral medium, while the consortium of all four strains degraded 9.2 mg L(-1) day(-1) of CP (100 mg L(-1)). Addition of glucose as an additional C source increased the degradation capacity by 8-14 %. After inoculation of contaminated soil with CP (200 mg kg(-1)) disappearance rates were 3.83-4.30 mg kg(-1) day(-1) for individual strains and 4.76 mg kg(-1) day(-1) for the consortium. These results indicate that these organisms are involved in the degradation of CP in soil and represent valuable candidates for in situ bioremediation of contaminated soils and waters.

  16. Assessing the influence of CH4 concentration during culture enrichment on the biodegradation kinetics and population structure.

    Science.gov (United States)

    López, Juan C; Quijano, Guillermo; Pérez, Rebeca; Muñoz, Raúl

    2014-12-15

    Methanotrophic communities were enriched in three stirred tank reactors continuously supplied with CH4-laden air at 20, 2 and 0.2 gCH4 m(-3) in order to evaluate the influence of CH4 concentration on the biodegradation kinetics, population structure and potential polyhydroxyalkanoate production under sequential nitrogen limitations. The population structure of the enriched cultures, dominated by type I methanotrophs, was influenced by CH4 concentration. No significant correlation between CH4 concentration and the maximum specific degradation rate (qmax) or the half-saturation constant (KS) was recorded, microorganisms enriched at 2 gCH4 m(-3) presenting the highest qmax and those enriched at 20 and 0.2 gCH4 m(-3) exhibiting the lowest KS. Maximum polyhydroxybutyrate (PHB) contents of 1.0% and 12.6% (w/w) were achieved at 20 and 2 g CH4 m(-3), respectively. Polyhydroxyvalerate (PHV) was also detected at PHV:PHB ratios of up to 12:1 and 4:1 in the communities enriched at 20 and 0.2 gCH4 m(-3), respectively.

  17. Potential effect of matrix stiffness on the enrichment of tumor initiating cells under three-dimensional culture conditions.

    Science.gov (United States)

    Liu, Chang; Liu, Yang; Xu, Xiao-xi; Wu, Hao; Xie, Hong-guo; Chen, Li; Lu, Ting; Yang, Li; Guo, Xin; Sun, Guang-wei; Wang, Wei; Ma, Xiao-jun; He, Xin

    2015-01-01

    Cancer stem cell (CSC) or tumor initiating cell (TIC) plays an important role in tumor progression and metastasis. Biophysical forces in tumor microenvironment have an important effect on tumor formation and development. In this study, the potential effect of matrix stiffness on the biological characteristics of human head and neck squamous cell carcinoma (HNSCC) TICs, especially the enrichment of HNSCC TICs, was investigated under three-dimensional (3D) culture conditions by means of alginate gel (ALG) beads with different matrix stiffnesses. ALG beads with soft (21 kPa), moderate (70 kPa) and hard (105 kPa) stiffness were generated by changing alginate concentration. It was found that significant HNSCC TIC enrichment was achieved in the ALG beads with moderate matrix stiffness (70 kPa). The gene expression of stemness markers Oct3/4 and Nanog, TIC markers CD44 and ABCG2 was enhanced in cells under this moderate (70 kPa) stiffness. HNSCC TIC proportion was also highly enriched under moderate matrix stiffness, accompanying with higher tumorigenicity, metastatic ability and drug resistance. And it was also found that the possible molecular mechanism underlying the regulated TIC properties by matrix stiffness under 3D culture conditions was significantly different from 2D culture condition. Therefore, the results achieved in this study indicated that 3D biophysical microenvironment had an important effect on TIC characteristics and alginate-based biomimetic scaffolds could be utilized as a proper platform to investigate the interaction between tumor cells and 3D microenvironment.

  18. Anaerobic taurine oxidation: a novel reaction by a nitrate-reducing Alcaligenes sp.

    Science.gov (United States)

    Denger, K; Laue, H; Cook, A M

    1997-06-01

    Enrichment cultures were prepared under strictly anoxic conditions in medium representing fresh water and containing an organosulfonate as electron donor and carbon source, and nitrate as electron acceptor. The inoculum was from the anaerobic digestor of two communal sewage works. The natural organosulfonates 2-aminoethanesulfonate (taurine), DL-2-amino-3-sulfopropionate (cysteate) and 2-hydroxyethanesulfonate (isethionate) all gave positive enrichments, whereas unsubstituted alkanesulfonates, such as methanesulfonate and arenesulfonates, gave no enrichment. Two representative enrichments were used to obtain pure cultures, and strains NKNTAU (utilizing taurine) and NKNIS (utilizing isethionate) were isolated. Strain NKNTAU was examined in detail. Out of 18 tested organosulfonates, it utilized only one, taurine, and was identified as a novel Alcaligenes sp., a facultatively anaerobic bacterium. Carbon from taurine was converted to cell material and carbon dioxide. The amino group was released as ammonium ion and the sulfonate moiety was recovered as sulfate. Nitrate was reduced to nitrogen gas.

  19. Effect of changing temperature on anaerobic hydrogen production and microbial community composition in an open-mixed culture bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Karadag, Dogan; Puhakka, Jaakko A. [Department of Chemistry and Bioengineering, Tampere University of Technology, Tampere (Finland)

    2010-10-15

    The temperature effect (37-65 C) on H{sub 2} production from glucose in an open-mixed culture bioreactor using an enrichment culture from a hot spring was studied. The dynamics of microbial communities was investigated by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). At 45 and 60 C the H{sub 2} production was the highest i.e. 1.71 and 0.85 mol H{sub 2}/mol glucose, respectively. No H{sub 2} was produced at temperatures 50 and 55 C. At 37-45 C, H{sub 2} production was produced by butyrate type fermentation while fermentation mechanism changed to ethanol type at 60 C. Clostridium species were dominant at 37-45 C while at 50-55 C and 60 C the culture was dominated by Bacillus coagulans and Thermoanaerobacterium, respectively. In the presence of B. Coagulans the metabolism was directed to lactate production. The results show that the mixed culture had two optima for H{sub 2} production and that the microbial communities and metabolic patterns promptly changed according to changing temperatures. (author)

  20. Evidence for the biogenic origin of manganese-enriched layers in Lake Superior sediments.

    Science.gov (United States)

    Palermo, Christine; Dittrich, Maria

    2016-04-01

    Manganese (Mn) and iron (Fe)-enriched sediment layers were discovered in Lake Superior within, above and below the oxic-anoxic interface. While the role of bacteria in redox reactions with Mn is known to be significant, little information exists about indigenous microbial communities in many freshwater environments. This study examined the bacterial communities of Mn-enriched layers in Lake Superior to identify the potential Mn(II) oxidizers responsible for the formation of Mn oxides. Anaerobic Mn(II) oxidation occurring in the Mn-enriched layers at the oxic-anoxic interface was investigated using Mn(II)-enriched cultures. High-resolution microscopic and spectroscopic investigations provided evidence of the biogenic formation of Mn oxides on cell surfaces. Spectroscopic mapping confirmed high levels of Mn in structures resembling biogenic Mn oxides. These structures were observed in enrichment cultures and in Mn-enriched layer sediment samples, indicating the significance of biogenic Mn oxidation occurring in situ. 16S ribosomal DNA pyrosequencing was used to identify the bacteria potentially responsible for Mnoxide formation in the enrichment cultures and Mn-enriched layers, revealing that the Mn-enriched layer contains classes with known Mn(II)-oxidizing members. Pyrosequencing of bacterial cultures suggested that these bacteria may be Bacillus strains, and that anaerobic microbial-mediated Mn(II) oxidation contributes to the formation of the layers.

  1. Evidence for the biogenic origin of manganese-enriched layers in Lake Superior sediments.

    Science.gov (United States)

    Palermo, Christine; Dittrich, Maria

    2016-04-01

    Manganese (Mn) and iron (Fe)-enriched sediment layers were discovered in Lake Superior within, above and below the oxic-anoxic interface. While the role of bacteria in redox reactions with Mn is known to be significant, little information exists about indigenous microbial communities in many freshwater environments. This study examined the bacterial communities of Mn-enriched layers in Lake Superior to identify the potential Mn(II) oxidizers responsible for the formation of Mn oxides. Anaerobic Mn(II) oxidation occurring in the Mn-enriched layers at the oxic-anoxic interface was investigated using Mn(II)-enriched cultures. High-resolution microscopic and spectroscopic investigations provided evidence of the biogenic formation of Mn oxides on cell surfaces. Spectroscopic mapping confirmed high levels of Mn in structures resembling biogenic Mn oxides. These structures were observed in enrichment cultures and in Mn-enriched layer sediment samples, indicating the significance of biogenic Mn oxidation occurring in situ. 16S ribosomal DNA pyrosequencing was used to identify the bacteria potentially responsible for Mnoxide formation in the enrichment cultures and Mn-enriched layers, revealing that the Mn-enriched layer contains classes with known Mn(II)-oxidizing members. Pyrosequencing of bacterial cultures suggested that these bacteria may be Bacillus strains, and that anaerobic microbial-mediated Mn(II) oxidation contributes to the formation of the layers. PMID:26636960

  2. Anaerobic bacteria in otitis media.

    Science.gov (United States)

    Fulghum, R S; Daniel, H J; Yarborough, J G

    1977-01-01

    Anaerobic bacteria, Peptostrepotococcus intermedius and Propionibacterium acnes, were found in mixed culture specimens from four to ten tested cases of chronic secretory otitis media. These anaerobic bacteria were in a mixed infection flora with aerobic bacteria most often Staphylococcus epidermidis and Cornybacterium sp. which do not fit any established species. The findings of anaerobic bacteria in otitis media is consistent with the sporadic report of the involvement of anaerobic bacteria in otitis media in the literature since 1898.

  3. Bioelectricity generation in microbial fuel cell using natural microflora and isolated pure culture bacteria from anaerobic palm oil mill effluent sludge.

    Science.gov (United States)

    Nor, Muhamad Hanif Md; Mubarak, Mohd Fahmi Muhammad; Elmi, Hassan Sh Abdirahman; Ibrahim, Norahim; Wahab, Mohd Firdaus Abdul; Ibrahim, Zaharah

    2015-08-01

    A double-chambered membrane microbial fuel cell (MFC) was constructed to investigate the potential use of natural microflora anaerobic palm oil mill effluent (POME) sludge and pure culture bacteria isolated from anaerobic POME sludge as inoculum for electricity generation. Sterilized final discharge POME was used as the substrate with no addition of nutrients. MFC operation using natural microflora anaerobic POME sludge showed a maximum power density and current density of 85.11mW/m(2) and 91.12mA/m(2) respectively. Bacterial identification using 16S rRNA analysis of the pure culture isolated from the biofilm on the anode MFC was identified as Pseudomonas aeruginosa strain ZH1. The electricity generated in MFC using P. aeruginosa strain ZH1 showed maximum power density and current density of 451.26mW/m(2) and 654.90mA/m(2) respectively which were five times higher in power density and seven times higher in current density compared to that of MFC using anaerobic POME sludge.

  4. Diversity of anaerobic microbes in spacecraft assembly clean rooms.

    Science.gov (United States)

    Probst, Alexander; Vaishampayan, Parag; Osman, Shariff; Moissl-Eichinger, Christine; Andersen, Gary L; Venkateswaran, Kasthuri

    2010-05-01

    Although the cultivable and noncultivable microbial diversity of spacecraft assembly clean rooms has been previously documented using conventional and state-of-the-art molecular techniques, the occurrence of obligate anaerobes within these clean rooms is still uncertain. Therefore, anaerobic bacterial communities of three clean-room facilities were analyzed during assembly of the Mars Science Laboratory rover. Anaerobic bacteria were cultured on several media, and DNA was extracted from suitable anaerobic enrichments and examined with conventional 16S rRNA gene clone library, as well as high-density phylogenetic 16S rRNA gene microarray (PhyloChip) technologies. The culture-dependent analyses predominantly showed the presence of clostridial and propionibacterial strains. The 16S rRNA gene sequences retrieved from clone libraries revealed distinct microbial populations associated with each clean-room facility, clustered exclusively within gram-positive organisms. PhyloChip analysis detected a greater microbial diversity, spanning many phyla of bacteria, and provided a deeper insight into the microbial community structure of the clean-room facilities. This study presents an integrated approach for assessing the anaerobic microbial population within clean-room facilities, using both molecular and cultivation-based analyses. The results reveal that highly diverse anaerobic bacterial populations persist in the clean rooms even after the imposition of rigorous maintenance programs and will pose a challenge to planetary protection implementation activities.

  5. Biodegradation of azo dyes in cocultures of anaerobic granular sludge with aerobic aromatic amine degrading enrichment cultures

    NARCIS (Netherlands)

    Tan, N.C.G.; Prenefeta-Boldú, F.X.; Opsteeg, J.L.; Lettinga, G.; Field, J.A.

    1999-01-01

    A prerequisite for the mineralization (complete biodegradation) of many azo dyes is a combination of reductive and oxidative steps. In this study, the biodegradation of two azo dyes, 4-phenylazophenol (4-PAP) and Mordant Yellow 10 (4-sulfophenylazo-salicylic acid; MY10), was evaluated in batch exper

  6. Enrichment strategy to select functional consortium from mixed cultures: Consortium from rumen liquor for simultaneous cellulose degradation and hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Aijie; Ren, Nanqi [State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); School of Environmental and Municipal Engineering, Harbin Institute of Technology, Harbin 150090 (China); Gao, Lingfang; Xu, Jifei; Liu, Chong; Lee, Duu-Jong [School of Environmental and Municipal Engineering, Harbin Institute of Technology, Harbin 150090 (China)

    2010-12-15

    Strain isolation using conventional roll tube/plating technique is time consuming and is able to culture in vitro only a small fraction of existing microbes in a natural microflora. This paper proposed a simple and rapid method to select the as-simple-as-possible biological consortium by serially diluting the original mixed culture. The diluted which remains, while the one diluted in serial loses the target function, is defined as the functional consortium of the original mixed culture. Since the microbial structure and the reaction pathway incorporated with the functional consortium is much simpler than its original mother liquor, detailed analysis on the strain interaction is possible without the risk of losing key functional strains as often caused from conventional isolation method. The rumen liquor that can degrade cellulose and produce hydrogen is used as a demonstration example. A ''rumen cellulose-degrading bacterial consortium'' (RCBC) was identified using the proposed enrichment strategy. (author)

  7. A novel anaerobic co-culture system for bio-hydrogen production from sugarcane bagasse.

    Science.gov (United States)

    Cheng, Jingrong; Zhu, Mingjun

    2013-09-01

    A novel co-culture of Clostridium thermocellum and Thermoanaerobacterium aotearoense with pretreated sugarcane bagasse (SCB) under mild alkali conditions for bio-hydrogen production was established, exhibiting a cost-effective and synergetic advantage in bio-hydrogen production over monoculture of C. thermocellum or T. aotearoense with untreated SCB. The optimized pretreatment conditions were established to be 3% NaOH, and a liquid to solid ratio of 25:1 at 80°C for 3h. A final hydrogen production of 50.05±1.51 mmol/L was achieved with 40 g/L pretreated SCB at 55°C. The established co-culture system provides a novel consolidated bio-processing strategy for bioconversion of SCB to bio-hydrogen.

  8. Biodiversity within hot spring microbial mat communities: molecular monitoring of enrichment cultures

    Science.gov (United States)

    Ward, D. M.; Santegoeds, C. M.; Nold, S. C.; Ramsing, N. B.; Ferris, M. J.; Bateson, M. M.

    1997-01-01

    We have begun to examine the basis for incongruence between hot spring microbial mat populations detected by cultivation or by 16S rRNA methods. We used denaturing gradient gel electrophoresis (DGGE) to monitor enrichments and isolates plated therefrom. At near extincting inoculum dilutions we observed Chloroflexus-like and cyanobacterial populations whose 16S rRNA sequences have been detected in the 'New Pit' Spring Chloroflexus mat and the Octopus Spring cyanobacterial mat. Cyanobacterial populations enriched from 44 to 54 degrees C and 56 to 63 degrees C samples at near habitat temperatures were similar to those previously detected in mat samples of comparable temperatures. However, a lower temperature enrichment from the higher temperature sample selected for the populations found in the lower temperature sample. Three Thermus populations detected by both DGGE and isolation exemplify even more how enrichment may bias our view of community structure. The most abundant population was adapted to the habitat temperature (50 degrees C), while populations adapted to 65 degrees C and 70 degrees C were 10(2)- and 10(4)-fold less abundant, respectively. However, enrichment at 70 degrees C favored the least abundant strain. Inoculum dilution and incubation at the habitat temperature favored the more numerically relevant populations. We enriched many other aerobic chemoorganotrophic populations at various inoculum dilutions and substrate concentrations, most of whose 16S rRNA sequences have not been detected in mats. A common feature of numerically relevant cyanobacterial, Chloroflexus-like and aerobic chemorganotrophic populations, is that they grow poorly and resist cultivation on solidified medium, suggesting plating bias, and that the medium composition and incubation conditions may not reflect the natural microenvironments these populations inhabit.

  9. Community Structure Evolution and Enrichment of Glycogen-Accumulating Organisms Producing Polyhydroxyalkanoates from Fermented Molasses▿

    OpenAIRE

    Pisco, Ana R.; Bengtsson, Simon; Werker, Alan; Reis, Maria A. M.; Lemos, Paulo C.

    2009-01-01

    An open mixed culture was enriched with glycogen-accumulating organisms (GAOs) by using a sequencing batch reactor and treating an agroindustrial waste (sugar cane molasses) under cyclic anaerobic-aerobic conditions. Over a 1-year operating period, the culture exhibited a very stable GAO phenotype with an average polyhydroxyalkanoate (PHA) content of 17% total suspended solids. However, the GAO microbial community evolved over the course of operation to a culture exhibiting unusual characteri...

  10. Metabolic energy-based modelling explains product yielding in anaerobic mixed culture fermentations.

    Directory of Open Access Journals (Sweden)

    Rebeca González-Cabaleiro

    Full Text Available The fermentation of glucose using microbial mixed cultures is of great interest given its potential to convert wastes into valuable products at low cost, however, the difficulties associated with the control of the process still pose important challenges for its industrial implementation. A deeper understanding of the fermentation process involving metabolic and biochemical principles is very necessary to overcome these difficulties. In this work a novel metabolic energy based model is presented that accurately predicts for the first time the experimentally observed changes in product spectrum with pH. The model predicts the observed shift towards formate production at high pH, accompanied with ethanol and acetate production. Acetate (accompanied with a more reduced product and butyrate are predicted main products at low pH. The production of propionate between pH 6 and 8 is also predicted. These results are mechanistically explained for the first time considering the impact that variable proton motive potential and active transport energy costs have in terms of energy harvest over different products yielding. The model results, in line with numerous reported experiments, validate the mechanistic and bioenergetics hypotheses that fermentative mixed cultures products yielding appears to be controlled by the principle of maximum energy harvest and the necessity of balancing the redox equivalents in absence of external electron acceptors.

  11. Conversion of methane-derived carbon and microbial community in enrichment cultures in response to O2 availability.

    Science.gov (United States)

    Wei, Xiao-Meng; He, Ruo; Chen, Min; Su, Yao; Ma, Ruo-Chan

    2016-04-01

    Methanotrophs not only play an important role in mitigating CH4 emissions from the environment, but also provide a large quantity of CH4-derived carbon to their habitats. In this study, the distribution of CH4-derived carbon and microbial community was investigated in a consortium enriched at three O2 tensions, i.e., the initial O2 concentrations of 2.5 % (LO-2), 5 % (LO-1), and 21 % (v/v) (HO). The results showed that compared with the O2-limiting environments (2.5 and 5 %), more CH4-derived carbon was converted into CO2 and biomass under the O2 sufficient condition (21 %). Besides biomass and CO2, a high conversion efficiency of CH4-derived carbon to dissolved organic carbon was detected in the cultures, especially in LO-2. Quantitative PCR and Miseq sequencing both showed that the abundance of methanotroph increased with the increasing O2 concentrations. Type II methanotroph Methylocystis dominated in the enrichment cultures, accounting for 54.8, 48.1, and 36.9 % of the total bacterial 16S rRNA gene sequencing reads in HO, LO-1, and LO-2, respectively. Methylotrophs, mainly including Methylophilus, Methylovorus, Hyphomicrobium, and Methylobacillus, were also abundant in the cultures. Compared with the O2 sufficient condition (21 %), higher microbial biodiversity (i.e., higher Simpson and lower Shannon indexes) was detected in LO-2 enriched at the initial O2 concentration of 2.5 %. These findings indicated that compared with the O2 sufficient condition, more CH4-derived carbon was exuded into the environments and promoted the growth of non-methanotrophic microbes in O2-limiting environments. PMID:26728286

  12. Effects of carbon sources on the enrichment of halophilic polyhydroxyalkanoate-storing mixed microbial culture in an aerobic dynamic feeding process

    Science.gov (United States)

    Cui, You-Wei; Zhang, Hong-Yu; Lu, Peng-Fei; Peng, Yong-Zhen

    2016-08-01

    Microbial polyhydroxyalkanoate (PHA) production serves as a substitute for petroleum-based plastics. Enriching mixed microbial cultures (MMCs) with the capacity to store PHA is a key precursor for low-cost PHA production. This study investigated the impact of carbon types on enrichment outcomes. Three MMCs were separately fed by acetate sodium, glucose, and starch as an enriching carbon source, and were exposed to long-term aerobic dynamic feeding (ADF) periods. The PHA production capacity, kinetics and stoichiometry of the enrichments, the PHA composition, and the microbial diversity and community composition were explored to determine carbon and enrichment correlations. After 350-cycle enriching periods under feast-famine (F-F) regimes, the MMCs enriched by acetate sodium and glucose contained a maximum PHA content of 64.7% and 60.5% cell dry weight (CDW). The starch-enriched MMC only had 27.3% CDW of PHA. High-throughput sequencing revealed that non-PHA bacteria survived alongside PHA storing bacteria, even under severe F-F selective pressure. Genus of Pseudomonas and Stappia were the possible PHA accumulating bacteria in acetate-enriched MMC. Genus of Oceanicella, Piscicoccus and Vibrio were found as PHA accumulating bacteria in glucose-enriched MMC. Vibrio genus was the only PHA accumulating bacteria in starch-enriched MMC. The community diversity and composition were regulated by the substrate types.

  13. Enrichment of carbon monoxide utilising microorganisms from methanogenic bioreactor sludge

    OpenAIRE

    Pereira, Ana Luísa; Stams, A.J.M.; Alves, M. M.; Sousa, D.Z.

    2015-01-01

    Conversion of CO is the rate limiting step during anaerobic conversion of syngas (a gaseous mixture mainly composed of CO, CO2 and H2). In this work we study the microbial diversity in anaerobic sludge submitted to extended contact to syngas in a multi-orifice baffled bioreactor (MOBB). Methane was the main product resulting from syngas conversion in the MOBB. Enrichment cultures started with this sludge produced methane as final product, but also acetate. 16S rRNA gene analysis revealed a pr...

  14. Thermo-acidophillic biohydrogen production from rice bran de-oiled wastewater by Selectively enriched mixed culture

    Directory of Open Access Journals (Sweden)

    D.Sivaramakrishna, D.Sreekanth, V.Himabindu, M.Lakshmi Narasu

    2010-07-01

    Full Text Available The present study focuses on the biohydrogen production in an anaerobic batch reactor operated at thermophillic (570C and acidophilic conditions (pH 6 with rice bran de-oiled wastewater (RBOW as substrate. The hydrogen generating mixed microflora was enriched from slaughter house sludge (SHS through acid treatment (pH 3-4, for 24h coupled with heat treatment (1h at 1000C to eliminate non-spore forming bacteria and to inhibit the growth of methanogenic bacteria (MB prior to inoculation in the reactor. The hydrogen production rate was maximum at 570C (1861±14ml/L-WW/d compared to 370C (651±30ml/L-ww/d. The Hydrogen yield increased with temperature from 1.1 to 2.2 molH2/mol of substrate respectively. The optimum pH range for hydrogen production in this system was observed in between 5.5 to 6. Acid-forming pathway with butyric acid as a major metabolite dominated the metabolic flow during the hydrogen production.

  15. Thermo-acidophillic biohydrogen production from rice bran de-oiled wastewater by Selectively enriched mixed culture

    Energy Technology Data Exchange (ETDEWEB)

    Sivaramakrishna, D.; Sreekanth, D.; Himabindu, V. [Centre for Environment, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally Hyderabad-500 085 (India); Narasu, M. Lakshmi [Centre for Biotechnology, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally Hyderabad-500 085 (India)

    2010-07-01

    The present study focuses on the biohydrogen production in an anaerobic batch reactor operated at thermophillic (570C) and acidophilic conditions (pH 6) with rice bran de-oiled wastewater (RBOW) as substrate. The hydrogen generating mixed microflora was enriched from slaughter house sludge (SHS) through acid treatment (pH 3-4, for 24h) coupled with heat treatment (1h at 1000C) to eliminate non-spore forming bacteria and to inhibit the growth of methanogenic bacteria (MB) prior to inoculation in the reactor. The hydrogen production rate was maximum at 570C (1861 +- 14ml/L-WW/d) compared to 370C (651 +- 30ml/L-ww/d). The Hydrogen yield increased with temperature from 1.1 to 2.2 molH2/mol of substrate respectively. The optimum pH range for hydrogen production in this system was observed in between 5.5 to 6. Acid-forming pathway with butyric acid as a major metabolite dominated the metabolic flow during the hydrogen production.

  16. Enrichment and activity of methanotrophic microorganisms from municipal wastewater sludge.

    Science.gov (United States)

    Siniscalchi, Luciene Alves Batista; Vale, Isabel Campante; Dell'Isola, Jéssica; Chernicharo, Carlos Augusto; Calabria Araujo, Juliana

    2015-01-01

    In this study, methanotrophic microorganisms were enriched from a municipal wastewater sludge taken from an Upflow Anaerobic Sludge Blanket reactor. The enrichment was performed in a sequencing batch reactor (SBR) with an autotrophic medium containing nitrite and nitrate. The microbial community composition of the inoculum and of the enrichment culture after 100 days of SBR operation was investigated and compared with the help of data obtained from 454 pyrosequencing analyses. The nitrite and nitrate removal efficiencies were 68% and 53%, respectively, probably due to heterotrophic denitrification. Archaeal cells of the anaerobic methanotrophic Archaic (ANME)-I and ANME-II groups were detected by polymerase chain reaction throughout the whole cultivation period. Pyrosequencing analysis showed that community composition was different among the two samples analysed. The dominant phyla found in the inoculum were Synergistestes, Firmicutes and Euryarchaeota, while Planctomycetes, Verrucomicrobia, Chloroflexi and Proteobacteria prevailed in the enriched biomass. The cultivation conditions decreased Methanobacterium abundance from 8% to 1%, and enriched for methanotrophic bacteria such as Methylocaldum, Methylocistis and Methylosinus. Sequences of Methylocaldum sp. accounted for 2.5% of the total reads. The presence and high predominance of Verrucomicrobia in the enriched biomass suggested that other unknown methanotrophic species related to that phylum might also have occurred in the reactor. Anaerobic methane oxidation activity was measured for both samples, and showed that the activity of the enrichment culture was nearly three times higher than the activity of the inoculum. Taken together, these results showed that the inoculum type and cultivation conditions were properly suited for methanotrophic enrichment. PMID:25495866

  17. Effects of CO2 enrichment and nutrients supply intermittency on batch cultures of Isochrysis galbana.

    Science.gov (United States)

    Picardo, Marta C; de Medeiros, José Luiz; Araújo, Ofélia de Queiroz F; Chaloub, Ricardo Moreira

    2013-09-01

    Aiming at enhanced performance to increase economic feasibility of microalgae based processes, Isochrysis galbana was grown in three modes of cultivation: batch, intermittent fed batch and semi-continuous. The batch mode was conducted under two regimes of aeration: conventional aeration and CO2 enriched aeration (5% v/v in air). Increased biomass productivity without significant impact on lipid accumulation was observed for CO2 enriched aeration relatively to cultivation aerated with air only. The intermittent fed batch cultivation policy was proven to be useful for lipid accumulation, increasing the lipid content by 19.8%. However, the semi-continuous mode resulted in higher productivity due to increased biomass concentration; the biomass productivity reached 0.51 g/(Ld). Fluorescence measurements were performed; the calculated low electron transport rate showed the need to increase the irradiance. The results showed that I. galbana can be grown in semi-continuous condition at high levels of biomass productivity.

  18. Passport to Cultural Enrichment: The Peace Corps World Wise Schools Experience

    Science.gov (United States)

    Carano, Kenneth T.

    2009-01-01

    In recent studies, youths in the United States have demonstrated a remarkable lack of cultural literacy. As the world is becoming increasingly interconnected, it is imperative that students enhance their understanding of other cultures. A classroom correspondence match with a Peace Corps volunteer through the Coverdell Peace Corps World Wise…

  19. Signatures of Autotrophic and Heterotrophic Metabolic Activity in Enrichment Cultures from a Sulphur Oxidizing Acid Mine Site

    Science.gov (United States)

    Slater, G. F.; Bernier, L.; Cowie, B. R.; Warren, L. A.

    2006-12-01

    Delineating the role of microorganisms in geochemical processes of interest in natural environments requires the development of tools that provide the ability to distinguish amongst microbial activity associated with different metabolic guilds. The gap between phylogenetic characterization and phenotypic understanding remains, underscoring the need to consider alternative methods. Compound specific analysis of cellular components has the potential to differentiate between active metabolic processes supporting microbial communities and may be especially useful in extreme environments. The goal of this study was to determine whether the phospholipids fatty acid (PLFA) distribution and isotopic signatures associated with autotrophs and heterotrophs enriched from an acid mine drainage (AMD) system differed, and further whether natural consortial autotrophic isolates showed similar signatures to autotrophic pure strains of Acidithiobacillus ferrooxidans and A. thiooxidans. Two distinct initial enrichments with tetrathionate and CO2 yielded primarily autotrophic (95%) Acidithiobaccillus spp. sulphur oxidizing communities. The remaining microbial members of theses enrichments (subculture of the consortial isolates in a medium amended with glucose but without tetrathionate selectively resulted in their visible growth. PLFA profiles and δ13C signatures from autotrophic (1) natural enrichments, pure cultures of (2) A. ferrooxidans and (3) A. thiooxidans were similar, but collectively differed from those of the natural heterotrophic enrichment cultures. The PLFA profiles for the heterotrophic communities were made up of primarily (88-99%) C16:0 and two isomers of C18:1. In contrast, the autotrophic communities had high proportions of C16:1 (up to 18%) as well as cyclo C17 and cyclo C19 PLFA that combined comprised 18 to 58% of the observed PLFA. The δ13C signatures of the PLFA also differed strongly between the two trophic levels. The δ13C of the autotrophic PLFA, - 24 to

  20. Improved Succinic Acid Production in the Anaerobic Culture of an Escherichia coli pflB ldhA Double Mutant as a Result of Enhanced Anaplerotic Activities in the Preceding Aerobic Culture▿

    OpenAIRE

    Wu, Hui; Li, Zhi-Min; Zhou, Li; Ye, Qin

    2007-01-01

    Escherichia coli NZN111 is a pflB ldhA double mutant which loses its ability to ferment glucose anaerobically due to redox imbalance. In this study, two-stage culture of NZN111 was carried out for succinic acid production. It was found that when NZN111 was aerobically cultured on acetate, it regained the ability to ferment glucose with succinic acid as the major product in subsequent anaerobic culture. In two-stage culture carried out in flasks, succinic acid was produced at a level of 11.26 ...

  1. Desulfurispira natronophila gen. nov. sp. nov.: an obligately anaerobic dissimilatory sulfur-reducing bacterium from soda lakes

    NARCIS (Netherlands)

    Sorokin, D.Y.; Muyzer, G.

    2010-01-01

    Anaerobic enrichment cultures with elemental sulfur as electron acceptor and either acetate or propionate as electron donor and carbon source at pH 10 and moderate salinity inoculated with sediments from soda lakes in Kulunda Steppe (Altai, Russia) resulted in the isolation of two novel members of t

  2. Survival of indicator organisms during enrichment on tetrachloroethene.

    Science.gov (United States)

    Skramstad, J D; Hurst, C J; Novak, P J

    2003-01-01

    A laboratory study was performed as the basis for a full-scale bioaugmentation project at a site contaminated with chlorinated ethenes. The objectives of this study were to 1) develop a protocol to enrich for a tetrachloroethene (PCE)-dechlorinating culture from waste activated sludge and anaerobic digester biosolids and 2) monitor the survival of fecal coliform bacteria and bacteriophage, which model enteric viruses, during the enrichment process. A culture was enriched in 8 days with the ability to degrade 6-microM PCE to cis-dichloroethene. Using the enrichment protocol in two identical experiments, significant inactivation of fecal coliform bacteria (2 log) and somatic coliphage (0.33 log) was observed in one of the experiments; no inactivation occurred in the second experiment. The number of F-specific coliphage decreased in both experiments (0.87 and 1.26 log inactivation). Despite the decrease in some of the coliform and bacteriophage numbers, the quantity of organisms and phage particles present after enrichment was still high (approximately 7.5 x 10(5) most probable number/L, 6.9 x 10(6) plaque-forming units (PFU)/L, and 3.3 x 10(5) PFU/L, for fecal coliform bacteria, somatic coliphage, and F-specific coliphage, respectively). This may be cause for concern, depending on the current and future groundwater use at or near a site undergoing bioaugmentation with cultures derived from waste activated sludge and anaerobic digester biosolids.

  3. Applicability of a Lactobacillus amylovorus strain as co-culture for natural folate bio-enrichment of fermented milk.

    Science.gov (United States)

    Laiño, Jonathan Emiliano; Juarez del Valle, Marianela; Savoy de Giori, Graciela; LeBlanc, Jean Guy Joseph

    2014-11-17

    The ability of 55 strains from different Lactobacillus species to produce folate was investigated. In order to evaluate folic acid productivity, lactobacilli were cultivated in the folate-free culture medium (FACM). Most of the tested strains needed folate for growth. The production and the extent of vitamin accumulation were distinctive features of individual strains. Lactobacillus amylovorus CRL887 was selected for further studies because of its ability to produce significantly higher concentrations of vitamin (81.2 ± 5.4 μg/L). The safety of this newly identified folate producing strain was evaluated through healthy experimental mice. No bacterial translocation was detected in liver and spleen after consumption of CRL887 during 7 days and no undesirable side effects were observed in the animals that received this strain. This strain in co-culture with previously selected folate producing starter cultures (Lactobacillus bulgaricus CRL871, and Streptococcus thermophilus CRL803 and CRL415) yielded a yogurt containing high folate concentrations (263.1 ± 2.4 μg/L); a single portion of which would provide 15% of the recommended dietary allowance. This is the first report where a Lactobacillus amylovorus strain was successfully used as co-culture for natural folate bio-enrichment of fermented milk.

  4. Reduction of Salmonella Typhimurium by Fermentation Metabolites of Diamond V Original XPC in an In Vitro Anaerobic Mixed Chicken Cecal Culture

    Science.gov (United States)

    Rubinelli, Peter; Roto, Stephanie; Kim, Sun Ae; Park, Si Hong; Pavlidis, Hilary O.; McIntyre, Don; Ricke, Steven C.

    2016-01-01

    Fermentation metabolites of Diamond V Original XPC™ (XPC), a biological product derived from yeast fermentation, were evaluated for their ability to reduce the Salmonella Typhimurium population using an in vitro mixed anaerobic culture system containing cecal microbiota to simulate chicken hindgut conditions. Four different samples were prepared: anaerobic mixed culture containing (1) feed only, (2) cecal only (ceca were harvested from 42 days old broiler chickens), (3) feed and cecal contents, and (4) feed, cecal contents, and 1% XPC. Two experimental conditions were investigated: Group 1, in which the cecal content was added at the same time as a S. Typhimurium marker strain and Group 2, in which the cecal content was preincubated for 24 h prior to the inoculation with the S. Typhimurium marker strain. The mixed cultures were incubated anaerobically at 37°C, and the S. Typhimurium marker strain was enumerated at 0, 24, and 48 h. Analysis of short chain fatty acids was also conducted for 24 h. In the Group 1 experiment, adding XPC did not exhibit significant reduction of S. Typhimurium. However, the presence of XPC resulted in rapid reduction of S. Typhimurium in Group 2. S. Typhimurium was reduced from 6.81 log10 CFU/ml (0 h) to 3.73 log10 CFU/ml and 1.19 log10 CFU/ml after 24 and 48 h, respectively. These levels were also 2.47 log10 and 2.72 log10 lower than the S. Typhimurium level recovered from the control culture with feed and cecal contents, but without XPC. Based on these results, it appears that the ability of XPC to reduce S. Typhimurium requires the presence of the cecal microbiota. Short chain fatty acid analysis indicated that acetate and butyrate concentrations of cultures containing XPC were twofold greater than the control cultures by 24 h of anaerobic growth. Results from the present study suggest that dietary inclusion of XPC may influence cecal microbiota fermentation and has the potential to reduce Salmonella in the cecum

  5. Reduction of Salmonella Typhimurium by Fermentation Metabolites of Diamond V Original XPC in an In Vitro Anaerobic Mixed Chicken Cecal Culture

    Science.gov (United States)

    Rubinelli, Peter; Roto, Stephanie; Kim, Sun Ae; Park, Si Hong; Pavlidis, Hilary O.; McIntyre, Don; Ricke, Steven C.

    2016-01-01

    Fermentation metabolites of Diamond V Original XPC™ (XPC), a biological product derived from yeast fermentation, were evaluated for their ability to reduce the Salmonella Typhimurium population using an in vitro mixed anaerobic culture system containing cecal microbiota to simulate chicken hindgut conditions. Four different samples were prepared: anaerobic mixed culture containing (1) feed only, (2) cecal only (ceca were harvested from 42 days old broiler chickens), (3) feed and cecal contents, and (4) feed, cecal contents, and 1% XPC. Two experimental conditions were investigated: Group 1, in which the cecal content was added at the same time as a S. Typhimurium marker strain and Group 2, in which the cecal content was preincubated for 24 h prior to the inoculation with the S. Typhimurium marker strain. The mixed cultures were incubated anaerobically at 37°C, and the S. Typhimurium marker strain was enumerated at 0, 24, and 48 h. Analysis of short chain fatty acids was also conducted for 24 h. In the Group 1 experiment, adding XPC did not exhibit significant reduction of S. Typhimurium. However, the presence of XPC resulted in rapid reduction of S. Typhimurium in Group 2. S. Typhimurium was reduced from 6.81 log10 CFU/ml (0 h) to 3.73 log10 CFU/ml and 1.19 log10 CFU/ml after 24 and 48 h, respectively. These levels were also 2.47 log10 and 2.72 log10 lower than the S. Typhimurium level recovered from the control culture with feed and cecal contents, but without XPC. Based on these results, it appears that the ability of XPC to reduce S. Typhimurium requires the presence of the cecal microbiota. Short chain fatty acid analysis indicated that acetate and butyrate concentrations of cultures containing XPC were twofold greater than the control cultures by 24 h of anaerobic growth. Results from the present study suggest that dietary inclusion of XPC may influence cecal microbiota fermentation and has the potential to reduce Salmonella in the cecum

  6. Comparative genomics of "Dehalococcoides ethenogenes" 195 and an enrichment culture containing unsequenced "Dehalococcoides" strains.

    Science.gov (United States)

    West, Kimberlee A; Johnson, David R; Hu, Ping; DeSantis, Todd Z; Brodie, Eoin L; Lee, Patrick K H; Feil, Helene; Andersen, Gary L; Zinder, Stephen H; Alvarez-Cohen, Lisa

    2008-06-01

    Tetrachloroethene (PCE) and trichloroethene (TCE) are prevalent groundwater contaminants that can be completely reductively dehalogenated by some "Dehalococcoides" organisms. A Dehalococcoides-organism-containing microbial consortium (referred to as ANAS) with the ability to degrade TCE to ethene, an innocuous end product, was previously enriched from contaminated soil. A whole-genome photolithographic microarray was developed based on the genome of "Dehalococcoides ethenogenes" 195. This microarray contains probes designed to hybridize to >99% of the predicted protein-coding sequences in the strain 195 genome. DNA from ANAS was hybridized to the microarray to characterize the genomic content of the ANAS enrichment. The microarray results revealed that the genes associated with central metabolism, including an apparently incomplete carbon fixation pathway, cobalamin-salvaging system, nitrogen fixation pathway, and five hydrogenase complexes, are present in both strain 195 and ANAS. Although the gene encoding the TCE reductase, tceA, was detected, 13 of the 19 reductive dehalogenase genes present in strain 195 were not detected in ANAS. Additionally, 88% of the genes in predicted integrated genetic elements in strain 195 were not detected in ANAS, consistent with these elements being genetically mobile. Sections of the tryptophan operon and an operon encoding an ABC transporter in strain 195 were also not detected in ANAS. These insights into the diversity of Dehalococcoides genomes will improve our understanding of the physiology and evolution of these bacteria, which is essential in developing effective strategies for the bioremediation of PCE and TCE in the environment. PMID:18359838

  7. Anaerobic culture on growth efficient bi-layered culture plate in a modified candle jar using a rapid and slow combustion system

    Directory of Open Access Journals (Sweden)

    P K Maiti

    2013-01-01

    Full Text Available Success for maximum isolation of anaerobes depends on maintaining critically low oxygen levels throughout and growth in a reduced medium with exclusion of inhibitory substances. Hence a dual system was used equipped with candle combustion for instant exhaustion of major part of oxygen from a sealed jar, along with acidified steel wool for residual oxygen purging. For inhibitory substances removal, test anaerobes were grown on anaerobic medium layered on buffer charcoal agar bed. After 48 hours incubation average colony sizes were compared with that of growths in conventional Gas-Pak system. Better growths were noted in the innovative system.

  8. Atrazine biodegradation efficiency, metabolite detection, and trzD gene expression by enrichment bacterial cultures from agricultural soil

    Institute of Scientific and Technical Information of China (English)

    Robinson David Jebakumar SOLOMON; Amit KUMAR; Velayudhan SATHEEJA SANTHI

    2013-01-01

    Atrazine is a selective herbicide used in agricultural fields to control the emergence of broadleaf and grassy weeds. The persistence of this herbicide is influenced by the metabolic action of habituated native microor-ganisms. This study provides information on the occurrence of atrazine mineralizing bacterial strains with faster me-tabolizing ability. The enrichment cultures were tested for the biodegradation of atrazine by high-performance liquid chromatography (HPLC) and mass spectrometry. Nine cultures JS01.Deg01 to JS09.Deg01 were identified as the degrader of atrazine in the enrichment culture. The three isolates JS04.Deg01, JS07.Deg01, and JS08.Deg01 were identified as efficient atrazine metabolizers. Isolates JS04.Deg01 and JS07.Deg01 produced hydroxyatrazine (HA) N-isopropylammelide and cyanuric acid by dealkylation reaction. The isolate JS08.Deg01 generated deethylatrazine (DEA), deisopropylatrazine (DIA), and cyanuric acid by N-dealkylation in the upper degradation pathway and later it incorporated cyanuric acid in their biomass by the lower degradation pathway. The optimum pH for degrading atrazine by JS08.Deg01 was 7.0 and 16S rDNA phylogenetic typing identified it as Enterobacter cloacae strain JS08.Deg01. The highest atrazine mineralization was observed in case of isolate JS08.Deg01, where an ample amount of trzD mRNA was quantified at 72 h of incubation with atrazine. Atrazine bioremediating isolate E. cloacae strain JS08.Deg01 could be the better environmental remediator of agricultural soils and the crop fields contaminated with atrazine could be the source of the efficient biodegrading microbial strains for the environmental cleanup process.

  9. Succession of lignocellulolytic bacterial consortia bred anaerobically from lake sediment

    NARCIS (Netherlands)

    Korenblum, Elisa; Jiménez Avella, Diego; van Elsas, Jan

    2016-01-01

    Anaerobic bacteria degrade lignocellulose in various anoxic and organically rich environments, often in a syntrophic process. Anaerobic enrichments of bacterial communities on a recalcitrant lignocellulose source were studied combining polymerase chain reaction–denaturing gradient gel electrophoresi

  10. Anaerobic Biodegradation of Tetrachloroethylene with Acetic Acid as Cometabolism Substrate under Anaerobic Condition

    Institute of Scientific and Technical Information of China (English)

    LI Ye; LIU Fei; CHEN Honghan; SHI Jinhua; WANG Yufan

    2008-01-01

    A series of batch-type experiments with acetate acid as the primary substrate wereperformed using enrichment cultures developed from the anaerobic sludge to investigate the effect ofacetate acid on tetrachloroethylene (PCE) biodegradation. Experimental results indicated that acetateacid was an efficient electron donor in affecting the biotransformability of PCE. Trichloroethylene(TCE) was the primary dehalogenation product, and small amounts of dichloroethylenes (DCEs) werealso detected. No significant further DCEs degradation was detected. PCE degradation rate in theexperiment was 36.6 times faster than background rate in natural groundwater.

  11. Biodegradation of Chlorpyrifos by Pseudomonas Resinovarans Strain AST2.2 Isolated from Enriched Cultures.

    Directory of Open Access Journals (Sweden)

    Anish Sharma*,

    2016-04-01

    Full Text Available A bacterial strain AST2.2 with chlorpyrifos degrading ability was isolated by enrichment technique from apple orchard soil with previous history of chlorpyrifos use. Based on the morphological, biochemical tests and 16S rRNA sequence analysis, AST2.2 strain was identified as Pseudomonas resinovarans. The strain AST2.2 utilized chlorpyrifos as the sole source of carbon and energy. This strain exhibited growth upto 400mg/l concentration of chlorpyrifos and exhibited high extracellular organophosphorus hydrolase (OPH activity. Gas chromatography-flame ionization detector (GC-FID studies revealed that Pseudomonas resinovarans AST2.2 degraded 43.90 % of chlorpyrifos (400 mg/l within 96 hrs. Intermediates of chlorpyrifos degradation were identified using GC-MS. This strain have potential to degrade chlorpyrifos and thus can be used for bioremediation and ecological restoration of sites contaminated with chlorpyrifos.

  12. Real-time PCR detection of Campylobacter spp.: A comparison toclassic culturing and enrichment

    NARCIS (Netherlands)

    Boer, P. de; Rahaoui, H.; Leer, R.J.; Montijn, R.C.; Vossen, J.M.B.M. van der

    2015-01-01

    The major disadvantage of the current gold standard for detection of the food pathogen Campylobacter, i.e. culturing, is the lengthy procedure. In this study we assessed the use of real-time PCR for detection of Campylobacter. To this end, 926 poultry samples, taken from transport containers and bro

  13. Stable acetate production in extreme-thermophilic (70°C) mixed culture fermentation by selective enrichment of hydrogenotrophic methanogens

    Science.gov (United States)

    Zhang, Fang; Zhang, Yan; Ding, Jing; Dai, Kun; van Loosdrecht, Mark C. M.; Zeng, Raymond J.

    2014-06-01

    The control of metabolite production is difficult in mixed culture fermentation. This is particularly related to hydrogen inhibition. In this work, hydrogenotrophic methanogens were selectively enriched to reduce the hydrogen partial pressure and to realize efficient acetate production in extreme-thermophilic (70°C) mixed culture fermentation. The continuous stirred tank reactor (CSTR) was stable operated during 100 days, in which acetate accounted for more than 90% of metabolites in liquid solutions. The yields of acetate, methane and biomass in CSTR were 1.5 +/- 0.06, 1.0 +/- 0.13 and 0.4 +/- 0.05 mol/mol glucose, respectively, close to the theoretical expected values. The CSTR effluent was stable and no further conversion occurred when incubated for 14 days in a batch reactor. In fed-batch experiments, acetate could be produced up to 34.4 g/L, significantly higher than observed in common hydrogen producing fermentations. Acetate also accounted for more than 90% of soluble products formed in these fed-batch fermentations. The microbial community analysis revealed hydrogenotrophic methanogens (mainly Methanothermobacter thermautotrophicus and Methanobacterium thermoaggregans) as 98% of Archaea, confirming that high temperature will select hydrogenotrophic methanogens over aceticlastic methanogens effectively. This work demonstrated a potential application to effectively produce acetate as a value chemical and methane as an energy gas together via mixed culture fermentation.

  14. Effects of Culture Media and Light Intensity on in vitro Growth of Oncidium under CO2 Enrichment Condition

    Institute of Scientific and Technical Information of China (English)

    He Songlin; Pan Huitang; Yang Qiusheng; Kong Dezheng; Zhang Qixiang; Michio Tanaka

    2003-01-01

    The effects of culture media and light intensity on in vitro growth of Oncidium 'Aloha Iwanga' were investigated under CO2 enrichment condition. Height, fresh and dry weight of the Oncidium seedlings were measured, and the leaf number per plant, shoot number per plant, leaf width and leaf chlorophyll content were also investigated. The results were as follows: 1) The seedling height, fresh and dry weight, leaf number per plant, leaf width and leaf chlorophyll content of the shoots growing on MS complete culture medium were higher than those on 1/2MS, VW and 1/2VW media. The root number per plant and ratio of dry matter of the seedlings cultured on 1/2MS and 1/2VW media were higher than those on MS and VW; 2) The seedling height, fresh weight, dry weight, dry matter ratio and leaf chlorophyll content, leaf length, leaf width, root length, leaf number per plant, root number per plant of seedlings of Oncidium growing under 4 500 lx and 1 700 lx were higher than those under 750 lx. However, there was no significant difference in those growth parameters mentioned above while dealing with 4 500 lx and 1 700 lx except for the seedling height. Nevertheless, the leaf color of plants under 4 500 lx was lighter and the leaves of the lower parts became yellowish in comparison with those growing under 1 700 lx.

  15. Nicotine suppresses lipopolysaccharide-induced release of interleukin-6 in mixed glia and microglia-enriched cultures

    Institute of Scientific and Technical Information of China (English)

    Zhihua Li; Qingzan Zhao; Hua Zhang; Xiuhua Ren; Mingfu Zhou; Weidong Zang

    2011-01-01

    Inflammation plays an important role in the pathogenesis of Parkinson's disease (PD) through the over-activation of microglia.Epidemiological studies show that smoking is associated with a lower incidence of PD.This study hypothesized that the neuroprotective effect of nicotine is mediated by modulating the activation of microglia via cytokine release.This study found that nicotine pretreatment suppressed the lipopolysaccharide-induced inflammatory reaction in the nervous system, especially microglia activation and interleukin-6 production.The inhibitory effects of 100 pmol/L nicotine were stronger compared with 1 and 10 pmol/L nicotine.These findings indicate that nicotine significantly decreases the production of proinflammatory interleukin-6 in mixed glia or microglia-enriched cultures, and plays an inhibitory effect on the lipopolysaccharide-induced inflammatory reaction.

  16. Biopolymer Production by Bacterial Enrichment Cultures Using Non-Fermented Substrates

    OpenAIRE

    Moralejo Gárate, H.

    2014-01-01

    Polyhydroxyalkanotes (PHAs) are naturally occurring polymers synthesized by a wide range of microorganisms. Their physiological role is to act as carbon and energy reserves, and their mechanical and physical properties are similar to those of petrochemical plastics. PHAs can be synthesized from renewable materials and they are biodegradable. Considering these properties, PHAs are commonly known as bioplastics. Commercial processes for the production of PHA are based on the use of pure culture...

  17. Enhanced biogas yield from energy crops with rumen anaerobic fungi

    Energy Technology Data Exchange (ETDEWEB)

    Prochazka, Jindrich; Zabranska, Jana; Dohanyos, Michal [Department of Water Technology and Environmental Engineering, Faculty of Environmental Technology, Institute of Chemical Technology in Prague, Prague (Czech Republic); Mrazek, Jakub; Strosova, Lenka; Fliegerova, Katerina [Laboratory of Anaerobic Microbiology, Institute of Animal Physiology and Genetics, CAS, v.v.i., Prague (Czech Republic)

    2012-06-15

    Anaerobic fungi (AF) are able to degrade crop substrates with higher efficiency than commonly used anaerobic bacteria. The aim of this study was to investigate ways of use of rumen AF to improve biogas production from energy crops under laboratory conditions. In this study, strains of AF isolated from feces or rumen fluid of cows and deer were tested for their ability to integrate into the anaerobic bacterial ecosystem used for biogas production, in order to improve degradation of substrate polysaccharides and consequently the biogas yield. Batch culture, fed batch culture, and semicontinuous experiments have been performed using anaerobic sludge from pig slurry fermentation and different kinds of substrates (celluloses, maize, and grass silage) inoculated by different genera of AF. All experiments showed a positive effect of AF on the biogas yield and quality. AF improved the biogas production by 4-22%, depending on the substrate and AF species used. However, all the cultivation experiments indicated that rumen fungi do not show long-term survival in fermenters with digestate from pig slurry. The best results were achieved during fed batch experiment with fungal culture Anaeromyces (KF8), in which biogas production was enhanced during the whole experimental period of 140 days. This result has not been achieved in semicontinuous experiment, where increment in biogas production in fungal enriched reactor was only 4% after 42 days. (copyright 2012 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Production of polyhydroxyalkanoates from fermented sugar cane molasses by a mixed culture enriched in glycogen accumulating organisms.

    Science.gov (United States)

    Bengtsson, Simon; Pisco, Ana R; Reis, Maria A M; Lemos, Paulo C

    2010-02-01

    Batch production of polyhydroxyalkanoates (PHAs) under aerobic conditions by an open mixed culture enriched in glycogen accumulating organisms (GAOs) with fermented sugar cane molasses as substrate was studied. The produced polymers contained five types of monomers, namely 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), 3-hydroxy-2-methylbutyrate (3H2MB), 3-hydroxy-2-methylvalerate (3H2MV) and the medium chain length monomer 3-hydroxyhexanoate (3HHx). With fermented molasses as substrate, PHA was produced under concurrent consumption of stored glycogen with yields of 0.47-0.66 C-mol PHA per C-mol of total carbon substrate and with rates up to 0.65 C-mol/C-molX h. In order to investigate the role of glycogen during aerobic PHA accumulation in GAOs, synthetic single volatile fatty acids (VFAs) were used as substrates and it was found that the fate of glycogen was dependent on the type of VFA being consumed. Aerobic PHA accumulation occurred under concurrent glycogen consumption with acetate as substrate and under minor concurrent glycogen production with propionate as substrate. With butyrate and valerate as substrates, PHA accumulation occurred with the glycogen pool unaffected. The composition of the PHA was dependent on the VFA composition of the fermented molasses and was 56-70 mol-% 3HB, 13-43 mol-% 3HV, 1-23 mol-% 3HHx and 0-2 mol-% 3H2MB and 3H2MV. The high polymer yields and production rates suggest that enrichment of GAOs can be a fruitful strategy for mixed culture production of PHA from waste substrates. PMID:19958801

  19. Chronic impact of sulfamethoxazole on the metabolic activity and composition of enriched nitrifying microbial culture.

    Science.gov (United States)

    Katipoglu-Yazan, Tugce; Merlin, Christophe; Pons, Marie-Noëlle; Ubay-Cokgor, Emine; Orhon, Derin

    2016-09-01

    This study investigated the chronic impact of sulfamethoxazole (SMX) on activated sludge sustaining an enriched nitrifying biomass. For this purpose, a laboratory scale fill and draw reactor was operated with 100 mg COD/L of peptone mixture and 50 mg N/L of ammonia at a sludge age of 15 days. Additionally, the biomass was exposed to a daily SMX dose of 50 mg/L once the reactor reached steady-state conditions. The reactor performance and microbial composition were monitored for 37 days with conventional parameters and molecular techniques based on the gene for ammonia monooxygenase subunit A (amoA) and the prokaryotic 16S rRNA gene. Denaturing gradient gel electrophoresis (DGGE) and 16S rRNA gene cloning analyses suggested a microbial community change concurrent with the addition of SMX. Specifically, quantitative polymerase chain reaction analyses (qPCR/RT-qPCR) revealed a significant reduction in the levels and activity of ammonia oxidizing bacteria (AOB). However, the acclimation period ended with high amoA mRNA levels and improved nitrification efficiency. Partial degradation of SMX by heterotrophic bacteria was also observed. PMID:27235775

  20. Isolation and identification of histone H3 protein enriched in microvesicles secreted from cultured sebocytes.

    Science.gov (United States)

    Nagai, Ayako; Sato, Takashi; Akimoto, Noriko; Ito, Akira; Sumida, Michihiro

    2005-06-01

    Secretion of microvesicles, defined as sebosomes, containing lipid particles were discovered for the first time in cultured sebocytes. After reaching confluency, hamster-cloned sebocytes released bubble-like microvesicles with a diameter range of 0.5-5.0 microm. They had a complex structure containing multiple Oil Red O-stainable particles. The lipid components of the microvesicles were large amounts of squalene both of hamster-cloned and rat primary cultured sebocytes. The microvesicles contained a concentrated 17-kDa cationic protein, which was soluble in sulfate buffer including Nonidet P-40 at pH 1.5. As the protein bound tightly to heparin-Sepharose and eluted with 1.5 M NaCl, it was further purified from a SDS-PAGE gel. Peptide sequencing identified the protein to be histone H3. Polyclonal antibodies against the purified protein detected the antigen in the microvesicles both in the hamster-cloned and rat primary cultured sebocytes. The antibodies demonstrated a distribution of the protein within the nucleus, cytoplasm, and precursor microvesicles. When a gene construct encoding histone H3-enhanced green fluorescent protein was transfected to the sebocytes, fluorescence of the fusion proteins was detected within both the nucleus and the precursor microvesicles of the cytoplasm. The distribution of heparan sulfate was evident in the microvesicles, and it suggested the possibility that the histone H3 protein was recruited and then condensed to the secreted microvesicles by the molecules. In addition, the 14-3-3 protein, which was detected in the microvesicles, also may help incorporate the histone H3 protein in the microvesicles because it can bind to both histone and lipid particles. PMID:15746254

  1. A discourse on creating and rendering educational and cultural enrichment services to rural migrant workers by public libraries

    Institute of Scientific and Technical Information of China (English)

    WANG; Zizhou; Charles; C.Yan

    2009-01-01

    As far as China’s enormous success in her economic reforms and development is concerned,Chinese rural migrant workers indeed have had their biggest share of contributions.Yet ironically in return,they have only received a disproportionate meager share of benefit rewards.These people represent a huge economically deprived group at the bottom of the social totem pole in China’s metropolises.On the whole as a social group,their educational attainment is relatively low as compared to their average urban coworkers.As such being the case,their rights to access some of the cost-free cultural and educational enrichment programs in the society are limited and not always assured.Nevertheless and in general speaking,they manifest a strong and consistent desire to acquire all sorts of new and practical knowledge by means of accessing the resources and facilities of their local public libraries.It is suggested in this paper that public libraries are in a good position to give strong support to the central government’s strategic planning for the development of a public culture service systema).In implementing such a government initiative with an unswerving purpose of advancing social justice and equality,public libraries should strife to provide as many as possible their library services at no cost to the public,especially to those socially deprived rural migrant workers.

  2. Enhancement of phenolics, resveratrol and antioxidant activity by nitrogen enrichment in cell suspension culture of Vitis vinifera.

    Science.gov (United States)

    Sae-Lee, Napaporn; Kerdchoechuen, Orapin; Laohakunjit, Natta

    2014-01-01

    Ammonium nitrate (NH4NO3), an important nitrogen source (34% N), has been used as an elicitor to stimulate plant growth and development as well as induce secondary metabolites under controlled conditions. In the present paper, we investigated the enhancement of cell biomass, total phenolics, resveratrol levels, and antioxidant activity of Vitis vinifera cv. Pok Dum by nitrogen enrichment (MS medium supplemented with NH4NO3 at 0, 500, 1,000, 5,000 and 10,000 mg/L). The highest accumulations of biomass, phenolics and resveratrol contents were observed at 8.8-fold (86.6 g DW/L), 15.9-fold (71.91 mg GAE/g DW) and 5.6-fold (277.89 µg/g DW) by the 14th day, in the medium supplemented with 500 mg/L NH4NO3. Moreover, the antioxidant activities of cultured grape cells estimated by the DPPH· and ABTS·+ assay were positively correlated with phenolics and resveratrol, and the maximum activity was also observed in cultured cells with 500 mg/L NH4NO3 at 176.11 and 267.79 mmol TE/100 g DW, respectively. PMID:24962393

  3. Enhancement of Phenolics, Resveratrol and Antioxidant Activity by Nitrogen Enrichment in Cell Suspension Culture of Vitis vinifera

    Directory of Open Access Journals (Sweden)

    Napaporn Sae-Lee

    2014-06-01

    Full Text Available Ammonium nitrate (NH4NO3, an important nitrogen source (34% N, has been used as an elicitor to stimulate plant growth and development as well as induce secondary metabolites under controlled conditions. In the present paper, we investigated the enhancement of cell biomass, total phenolics, resveratrol levels, and antioxidant activity of Vitis vinifera cv. Pok Dum by nitrogen enrichment (MS medium supplemented with NH4NO3 at 0, 500, 1,000, 5,000 and 10,000 mg/L. The highest accumulations of biomass, phenolics and resveratrol contents were observed at 8.8-fold (86.6 g DW/L, 15.9-fold (71.91 mg GAE/g DW and 5.6-fold (277.89 µg/g DW by the 14th day, in the medium supplemented with 500 mg/L NH4NO3. Moreover, the antioxidant activities of cultured grape cells estimated by the DPPH· and ABTS·+ assay were positively correlated with phenolics and resveratrol, and the maximum activity was also observed in cultured cells with 500 mg/L NH4NO3 at 176.11 and 267.79 mmol TE/100 g DW, respectively.

  4. More Than "Getting Us Through:" A Case Study in Cultural Capital Enrichment of Underrepresented Minority Undergraduates.

    Science.gov (United States)

    Ovink, Sarah M; Veazey, Brian D

    2011-01-01

    Minority students continue to be underrepresented among those who seek graduate and professional degrees in the sciences. Much previous research has focused on academic preparation. Equally important, however, are the psychological-social barriers and lack of institutional support encountered by many minority students. We present a case study of a university-sponsored intervention program for minority science majors that addresses not only academics, but also socialization into the academic community, networking, and the ability to practice newfound skills and dispositions through undergraduate research. In examining this case, we suggest that concerted, formal efforts toward expanding habitus and thereby augmenting cultural and social capital may have positive effects for underrepresented minority (URM) college students' academic and career prospects. Moreover, we argue that these differences complement the gains program participants make in academic preparedness, showing that attention to academics alone may be insufficient for addressing longstanding inequities in science career attainment among URM students. PMID:24954971

  5. A semi-continuous culture system for production of cellulolytic and xylanolytic enzymes by the anaerobic fungus Piromyces sp. strain E2

    Energy Technology Data Exchange (ETDEWEB)

    Teunissen, M.J.; Baerends, R.J.S.; Knelissen, R.A.G.; Camp, H.J.M. op den; Vogels, G.D. (Katholieke Univ., Nijmegen (Netherlands). Dept. of Microbiology)

    1992-10-01

    A system was developed for the semi-continous cultivation of an anaerobic fungus, Piromyces sp. strain E2 (isolated from an Indian elephant), on Avicel (microcrystalline cellulose). The fungus was grown in a semi-continuous culture system: Solids and fungal biomass was retained by means of a simple filter construction whereas the culture fluid was removed continuously. The production of fermentation products (acetate, ethanol, formate, lactate, hydrogen or methane), cellulolytic and xylanolytic enzymes, and protein by the fungus in monoculture or co-culture with Methanobacterium formicicum during growth on Avicel was monitored up to 45 days. These productions stabilized after an adaptation period of 24 and 30 days in the semi-continuous co-culture and monoculture, respectively. After this period the average ([+-]SD) avicelase, [beta]-glucosidase, endoglucanase, and xylanase production in the semicontinuous monoculture were 27[+-]6, 140[+-]16, 1057[+-]120 and 5012[+-]583 IUxl[sup -1]xday[sup -1], respectively. Co-culture with the methanogen caused a shift in fermentation products to more acetate, and less ethanol and lactate. Furthermore, the production of all cellulolytic enzymes increased (40%) and xylanolytic enzyme production decreased (35%). (orig.).

  6. Characterization of bacterial diversity in an atrazine degrading enrichment culture and degradation of atrazine, cyanuric acid and biuret in industrial wastewater.

    Science.gov (United States)

    Dutta, Anirban; Vasudevan, Venugopal; Nain, Lata; Singh, Neera

    2016-01-01

    An enrichment culture was used to study atrazine degradation in mineral salt medium (MSM) (T1), MSM+soil extract (1:1, v/v) (T2) and soil extract (T3). Results suggested that enrichment culture required soil extract to degrade atrazine, as after second sequential transfer only partial atrazine degradation was observed in T1 treatment while atrazine was completely degraded in T2 and T3 treatments even after fourth transfer. Culture independent polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique confirmed selective enrichment of genus Bacillus along with Pseudomonas and Burkholderia. Degradation of atrazine/metabolites in the industrial wastewater was studied at different initial concentrations of the contaminants [wastewater-water (v/v) ratio: T1, 1:9; T2, 2:8; T3, 3:7; T4, 5:5 and T5, undiluted effluent]. The initial concentrations of atrazine, cyanuric acid and biuret ranged between 5.32 and 53.92 µg mL(-1), 265.6 and 1805.2 µg mL(-1) and 1.85 and 16.12 µg mL(-1), respectively. The enrichment culture was able to completely degrade atrazine, cyanuric acid and biuret up to T4 treatment, while no appreciable degradation of contaminants was observed in the undiluted effluent (T5). Inability of enrichment culture to degrade atrazine/metabolites might be due to high concentrations of cyanuric acid. Therefore, a separate study on cyanuric acid degradation suggested: (i) no appreciable cyanuric acid degradation with accumulation of an unidentified metabolite in the medium where cyanuric acid was supplemented as the sole source of carbon and nitrogen; (ii) partial cyanuric acid degradation with accumulation of unidentified metabolite in the medium containing additional nitrogen source; and (iii) complete cyanuric acid degradation in the medium supplemented with an additional carbon source. This unidentified metabolite observed during cyanuric acid degradation and also detected in the enrichment culture inoculated wastewater samples

  7. Characterization of bacterial diversity in an atrazine degrading enrichment culture and degradation of atrazine, cyanuric acid and biuret in industrial wastewater.

    Science.gov (United States)

    Dutta, Anirban; Vasudevan, Venugopal; Nain, Lata; Singh, Neera

    2016-01-01

    An enrichment culture was used to study atrazine degradation in mineral salt medium (MSM) (T1), MSM+soil extract (1:1, v/v) (T2) and soil extract (T3). Results suggested that enrichment culture required soil extract to degrade atrazine, as after second sequential transfer only partial atrazine degradation was observed in T1 treatment while atrazine was completely degraded in T2 and T3 treatments even after fourth transfer. Culture independent polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique confirmed selective enrichment of genus Bacillus along with Pseudomonas and Burkholderia. Degradation of atrazine/metabolites in the industrial wastewater was studied at different initial concentrations of the contaminants [wastewater-water (v/v) ratio: T1, 1:9; T2, 2:8; T3, 3:7; T4, 5:5 and T5, undiluted effluent]. The initial concentrations of atrazine, cyanuric acid and biuret ranged between 5.32 and 53.92 µg mL(-1), 265.6 and 1805.2 µg mL(-1) and 1.85 and 16.12 µg mL(-1), respectively. The enrichment culture was able to completely degrade atrazine, cyanuric acid and biuret up to T4 treatment, while no appreciable degradation of contaminants was observed in the undiluted effluent (T5). Inability of enrichment culture to degrade atrazine/metabolites might be due to high concentrations of cyanuric acid. Therefore, a separate study on cyanuric acid degradation suggested: (i) no appreciable cyanuric acid degradation with accumulation of an unidentified metabolite in the medium where cyanuric acid was supplemented as the sole source of carbon and nitrogen; (ii) partial cyanuric acid degradation with accumulation of unidentified metabolite in the medium containing additional nitrogen source; and (iii) complete cyanuric acid degradation in the medium supplemented with an additional carbon source. This unidentified metabolite observed during cyanuric acid degradation and also detected in the enrichment culture inoculated wastewater samples

  8. Geochemical diversity in S processes mediated by culture-adapted and environmental-enrichments of Acidithiobacillus spp.

    Science.gov (United States)

    Bernier, Luc; Warren, Lesley A.

    2007-12-01

    Coupled S speciation and acid generation resulting from S processing associated with five different microbial treatments, all primarily Acidithiobacillus spp. (i.e. autotrophic S-oxidizers) were evaluated in batch laboratory experiments. Microbial treatments included two culture-adapted strains, Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans, their consortia and two environmental enrichments from a mine tailings lake that were determined to be >95% Acidithiobacillus spp., by whole-cell fluorescent hybridization. Using batch experiments simulating acidic mine waters with no carbon amendments, acid generation, and S speciation associated with the oxidation of three S substrates (thiosulfate, tetrathionate, and elemental S) were evaluated. Aseptic controls showed no observable pH decrease over the experimental time course (1 month) for all three S compounds examined. In contrast, pH decreased in all microbial treatments from starting pH values of 4 to 2 or less for all three S substrates. Results show a non-linear relationship between the pH dynamics of the batch cultures and their corresponding sulfate concentrations, and indicate how known microbial S processing pathways have opposite impacts, ultimately on pH dynamics. Associated geochemical modeling indicated negligible abiogenic processes contributing to the observed results, indicating strong microbial control of acid generation extending over pH ranges from 4 to less than 2. However, the observed acid generation rates and associated S speciation were both microbial treatment and substrate-specific. Results reveal a number of novel insights regarding microbial catalysis of S oxidation: (1) metabolic diversity in S processing, as evidenced by the observed geochemical signatures in S chemical speciation and rates of acid generation amongst phylogenetically similar organisms (to the genus level); (2) consortial impacts differ from those of individual strain members; (3) environmental enrichments

  9. 降解对苯二甲酸厌氧微生物群快速驯化与富集技术%Quick enrichment & acclimation of an anaerobic microbial consortium used for biodegrading terephthalic acid(TA)

    Institute of Scientific and Technical Information of China (English)

    李小明; 陈坚; 伦世仪

    2001-01-01

    来自甲烷发酵的厌氧污泥在反硝化条件下,可以对苯二甲酸(Terephthalic Acid,简称TA)为唯一碳源快速驯化富集TA厌氧降解菌,然后转换到甲烷发酵状态,到第6周时,获得的TA降解速度为22.6mgTA/gVSS*day,是对照实验的2.1倍。经过约90天的驯化,原存在于种污泥中的发酵性细菌几乎全部消亡,新的培养物中取而代之的是TA还原和开环菌,TA降解菌的驯化过程和富集过程是偶联的。MPN计数和滚管计数进一步证实了上述结果。%The seed sludge originated from a methane fermentation reactor can be enriched and acclimated quickly with TA as sole carbon source for TA anaerobic degradation under nitrate respiration mode first,and then under methane fermentation mode.Through 6-week process,a 22.6mgTA/gVSS*day TA degradation rate was obtained,which was 2.1 times of the rate got from normal acclimation process.After a total of 90 days for the enrichment and acclimation,the fermentative bacteria which originally existed in the seed sludge nearly disappeared,and instead of them,the TA reductive and cleaving bacteria group was formed in the new consortium,which was confirmed by the MPN counts and roll tube counts.

  10. Simple and Versatile Turbidimetric Monitoring of Bacterial Growth in Liquid Cultures Using a Customized 3D Printed Culture Tube Holder and a Miniaturized Spectrophotometer: Application to Facultative and Strictly Anaerobic Bacteria

    Science.gov (United States)

    Maia, Margarida R. G.; Marques, Sara; Cabrita, Ana R. J.; Wallace, R. John; Thompson, Gertrude; Fonseca, António J. M.; Oliveira, Hugo M.

    2016-01-01

    Here we introduce a novel strategy for turbidimetric monitoring of bacterial growth in liquid culture. The instrumentation comprises a light source, a customized 3D printed culture tube holder and a miniaturized spectrophotometer, connected through optical cables. Due to its small footprint and the possibility to operate with external light, bacterial growth was directly monitored from culture tubes in a simple and versatile fashion. This new portable measurement technique was used to monitor the growth of facultative (Escherichia coli ATCC/25922, and Staphylococcus aureus ATCC/29213) and strictly (Butyrivibrio fibrisolvens JW11, Butyrivibrio proteoclasticus P18, and Propionibacterium acnes DSMZ 1897) anaerobic bacteria. For E. coli and S. aureus, the growth rates calculated from normalized optical density values were compared with those ones obtained using a benchtop spectrophotometer without significant differences (P = 0.256). For the strictly anaerobic species, a high precision (relative standard deviation < 3.5%) was observed between replicates up to 48 h. Regarding its potential for customization, this manifold could accommodate further developments for customized turbidimetric monitoring, such as the use of light-emitting diodes as a light source or flow cells. PMID:27630632

  11. Simple and versatile turbidimetric monitoring of bacterial growth in liquid cultures using a customized 3D printed culture tube holder and a miniaturized spectrophotometer: application to facultative and strictly anaerobic bacteria

    Directory of Open Access Journals (Sweden)

    Margarida R. G. Maia

    2016-08-01

    Full Text Available Here we introduce a novel strategy for turbidimetric monitoring of bacterial growth in liquid culture. The instrumentation comprises a light source, a customized 3D printed culture tube holder and a miniaturized spectrophotometer, connected through optical cables. Due to its small footprint and the possibility to operate with external light, bacterial growth was directly monitored from culture tubes in a simple and versatile fashion. This new portable measurement technique was used to monitor the growth of facultative (Escherichia coli ATCC/25922, and Staphylococcus aureus ATCC/29213 and strictly (Butyrivibrio fibrisolvens JW11, Butyrivibrio proteoclasticus P18, and Propionibacterium acnes DSMZ 1897 anaerobic bacteria. For E. coli and S. aureus, the growth rates calculated from normalized optical density values were compared with those ones obtained using a benchtop spectrophotometer without significant differences (P = 0.256. For the strictly anaerobic species, a high precision (RSD < 3.5% was observed between replicates up to 48 h. Regarding its potential for customization, this manifold could accommodate further developments for customized turbidimetric monitoring, such as the use of light-emitting diodes as a light source or flow cells.

  12. Simple and Versatile Turbidimetric Monitoring of Bacterial Growth in Liquid Cultures Using a Customized 3D Printed Culture Tube Holder and a Miniaturized Spectrophotometer: Application to Facultative and Strictly Anaerobic Bacteria.

    Science.gov (United States)

    Maia, Margarida R G; Marques, Sara; Cabrita, Ana R J; Wallace, R John; Thompson, Gertrude; Fonseca, António J M; Oliveira, Hugo M

    2016-01-01

    Here we introduce a novel strategy for turbidimetric monitoring of bacterial growth in liquid culture. The instrumentation comprises a light source, a customized 3D printed culture tube holder and a miniaturized spectrophotometer, connected through optical cables. Due to its small footprint and the possibility to operate with external light, bacterial growth was directly monitored from culture tubes in a simple and versatile fashion. This new portable measurement technique was used to monitor the growth of facultative (Escherichia coli ATCC/25922, and Staphylococcus aureus ATCC/29213) and strictly (Butyrivibrio fibrisolvens JW11, Butyrivibrio proteoclasticus P18, and Propionibacterium acnes DSMZ 1897) anaerobic bacteria. For E. coli and S. aureus, the growth rates calculated from normalized optical density values were compared with those ones obtained using a benchtop spectrophotometer without significant differences (P = 0.256). For the strictly anaerobic species, a high precision (relative standard deviation < 3.5%) was observed between replicates up to 48 h. Regarding its potential for customization, this manifold could accommodate further developments for customized turbidimetric monitoring, such as the use of light-emitting diodes as a light source or flow cells.

  13. Cultivation and irradiation of human fibroblasts in a medium enriched with platelet lysate for obtaining feeder layer in epidermal cell culture

    International Nuclear Information System (INIS)

    For over 30 years, the use of culture medium, enriched with bovine serum, and murines fibroblasts, with the rate of proliferation controlled by irradiation or by share anticarcinogenic drugs, has been playing successfully its role in assisting in the development of keratinocytes in culture, for clinical purposes. However, currently there is a growing concern about the possibility of transmitting prions and animals viruses to transplanted patients. Taking into account this concern, the present work aims to cultivate human fibroblasts in a medium enriched with human platelets lysate and determine the irradiation dose of these cells, for obtaining feeder layer in epidermal cell culture. For carrying out the proposed objective, platelets lysis has standardized, this lysate was used for human fibroblasts cultivation and the irradiation dose enough to inhibit its duplication was evaluated. Human keratinocytes were cultivated in these feeder layers, in culture medium enriched with the lysate. With these results we conclude that the 10% platelets lysate promoted a better adhesion and proliferation of human fibroblasts and in all dose levels tested (60 to 300 Gy), these had their mitotic activity inactivated by ionizing irradiation, being that the feeder layers obtained with doses from 70 to 150 Gy were those that provided the best development of keratinocytes in medium containing 2.5% of human platelet lysate. Therefore, it was possible to standardize both the cultivation of human fibroblasts as its inactivation for use as feeder layer in culture of keratinocytes, so as to eliminate xenobiotics components. (author)

  14. Rapid and Specific Enrichment of Culturable Gram Negative Bacteria Using Non-Lethal Copper-Free Click Chemistry Coupled with Magnetic Beads Separation.

    Science.gov (United States)

    Fugier, Emilie; Dumont, Audrey; Malleron, Annie; Poquet, Enora; Mas Pons, Jordi; Baron, Aurélie; Vauzeilles, Boris; Dukan, Sam

    2015-01-01

    Currently, identification of pathogenic bacteria present at very low concentration requires a preliminary culture-based enrichment step. Many research efforts focus on the possibility to shorten this pre-enrichment step which is needed to reach the minimal number of cells that allows efficient identification. Rapid microbiological controls are a real public health issue and are required in food processing, water quality assessment or clinical pathology. Thus, the development of new methods for faster detection and isolation of pathogenic culturable bacteria is necessary. Here we describe a specific enrichment technique for culturable Gram negative bacteria, based on non-lethal click chemistry and the use of magnetic beads that allows fast detection and isolation. The assimilation and incorporation of an analog of Kdo, an essential component of lipopolysaccharides, possessing a bio-orthogonal azido function (Kdo-N3), allow functionalization of almost all Gram negative bacteria at the membrane level. Detection can be realized through strain-promoted azide-cyclooctyne cycloaddition, an example of click chemistry, which interestingly does not affect bacterial growth. Using E. coli as an example of Gram negative bacterium, we demonstrate the excellent specificity of the technique to detect culturable E. coli among bacterial mixtures also containing either dead E. coli, or live B. subtilis (as a model of microorganism not containing Kdo). Finally, in order to specifically isolate and concentrate culturable E. coli cells, we performed separation using magnetic beads in combination with click chemistry. This work highlights the efficiency of our technique to rapidly enrich and concentrate culturable Gram negative bacteria among other microorganisms that do not possess Kdo within their cell envelope.

  15. Biodegradation of Various Aromatic Compounds by Enriched Bacterial Cultures: Part B--Nitrogen-, Sulfur-, and Oxygen-Containing Heterocyclic Aromatic Compounds.

    Science.gov (United States)

    Oberoi, Akashdeep Singh; Philip, Ligy; Bhallamudi, S Murty

    2015-07-01

    Present study focused on the biodegradation of various heterocyclic nitrogen, sulfur, and oxygen (NSO) compounds using naphthalene-enriched culture. Target compounds in the study were pyridine, quinoline, benzothiophene, and benzofuran. Screening studies were carried out using different microbial consortia enriched with specific polycyclic aromatic hydrocarbon (PAH) and NSO compounds. Among different microbial consortia, naphthalene-enriched culture was the most efficient consortium based on high substrate degradation rate. Substrate degradation rate with naphthalene-enriched culture followed the order pyridine > quinoline > benzofuran > benzothiophene. Benzothiophene and benzofuran were found to be highly recalcitrant pollutants. Benzothiophene could not be biodegraded when concentration was above 50 mg/l. It was observed that 2-(1H)-quinolinone, benzothiophene-2-one, and benzofuran-2,3-dione were formed as metabolic intermediates during biodegradation of quinoline, benzothiophene, and benzofuran, respectively. Quinoline-N and pyridine-N were transformed into free ammonium ions during the biodegradation process. Biodegradation pathways for various NSO compounds are proposed. Monod inhibition model was able to simulate single substrate biodegradation kinetics satisfactorily. Benzothiophene and benzofuran biodegradation kinetics, in presence of acetone, was simulated using a generalized multi-substrate model.

  16. Molecular analysis of enrichment cultures of ammonia oxidizers from the Salar de Huasco, a high altitude saline wetland in northern Chile.

    Science.gov (United States)

    Dorador, Cristina; Busekow, Annika; Vila, Irma; Imhoff, Johannes F; Witzel, Karl-Paul

    2008-05-01

    We analyzed enrichment cultures of ammonia-oxidizing bacteria (AOB) collected from different areas of Salar de Huasco, a high altitude, saline, pH-neutral water body in the Chilean Altiplano. Samples were inoculated into mineral media with 10 mM NH4+ at five different salt concentrations (10, 200, 400, 800 and 1,400 mM NaCl). Low diversity (up to three phylotypes per enrichment) of beta-AOB was detected using 16S rDNA and amoA clone libraries. Growth of beta-AOB was only recorded in a few enrichment cultures and varied according to site or media salinity. In total, five 16S rDNA and amoA phylotypes were found which were related to Nitrosomonas europaea/Nitrosococcus mobilis, N. marina and N. communis clusters. Phylotype 1-16S was 97% similar with N. halophila, previously isolated from Mongolian soda lakes, and phylotypes from amoA sequences were similar with yet uncultured beta-AOB from different biofilms. Sequences related to N. halophila were frequently found at all salinities. Neither gamma-AOB nor ammonia-oxidizing Archaea were recorded in these enrichment cultures. PMID:18305895

  17. Detection of Mycoplasma ovipneumoniae and M. arginini in bighorn sheep using enrichment culture coupled with genus- and species-specific polymerase chain reaction.

    Science.gov (United States)

    Weiser, Glen C; Drew, Mark L; Cassirer, E Frances; Ward, Alton C S

    2012-04-01

    Mycoplasma species are of interest as possible primary pathogens in the pneumonia complex of bighorn sheep (Ovis canadensis). Previous investigations have not commonly detected low frequencies of Mycoplasma spp. from free-ranging bighorn sheep, possibly due to the fastidious and slow growth of these organisms. We developed a culture protocol that employed an average initial 3-day enrichment culture in liquid Hayflick broth in a CO(2)-enhanced atmosphere. The broth was plated to solid Hayflick medium and the cultures observed for growth for up to 30 days. Polymerase chain reaction (PCR) was performed on DNA isolated from the enrichment broth and on isolates obtained from culture using Mycoplasma genus-specific PCR assays and species-specific PCR assays for M. arginini and M. ovipneumoniae. Some cultures that grew on Hayflick plates were picked as single colonies but were mixed because two organisms may grow together and appear as a single colony. Culture and PCR tests produced similar results for M. arginini, but for M. ovipneumoniae, culture alone was less accurate than PCR. Use of genus-specific primers also may allow detection of other species in samples negative for M. arginini and M. ovipneumoniae. Two methods of transport from field to laboratory (Port-a-Cul™ tubes, cryoprotectant in liquid N(2) and Fisher Transport System) gave similar results under our study conditions.

  18. Prevalence of Anaerobic and Aerobic Bacteria in Early Onset Neonatal Sepsis

    Directory of Open Access Journals (Sweden)

    F Nili

    2008-09-01

    Full Text Available "nBackground: To determine prospectively the prevalence of anaerobic and aerobic infection in early onset (during 72 hours of age neonatal sepsis, in Tehran Vali-e-Asr Hospital."nMethods: Among all the live birth, neonates suspecting of having septicemia were investigated for isolation of micro­organisms. Culture bottle containing enriched tryptic soy broth was used for standard blood culture system to detect aerobes and an ANAEROBIC/F bottle was inoculated using BACTEC 9120 continuous monitoring blood culture system to deter­mine the growth of anaerobic bacteria. Among 1724 live births, 402 consecutive neonates suspecting of having septicemia were investigated for isolation of micro organism."nResults: A total of 27 episodes of early onset neonatal sepsis occurred with an incidence of 15.66 (11.6 aerobe + 4.0 anaer­obe per 1000 live births. Aerobic bacteria were the major etiological agents, accounting for 20 cases. 7 (26% cases had posi­tive blood cultures with anaerobic bacteria. Propionibacterium and Peptostreptococccus (amongst anaerobic and coagu­lase-negative staphylococci and staphylococcus aureus (amongst aerobic were the most commonly isolated organisms. Compari­son of clinical findings and demographic characteristics between aerobic and anaerobic infection did not have a signifi­cant statistical difference."nConclusion: Our impression is that while anaerobic bacteremia in the newborn infants can occasionally cause severe morbid­ity and mortality, majority of cases experience a self limited illness with transient bacteremia.

  19. Anaerobic degradation of benzene by marine sulfate-reducing bacteria

    Science.gov (United States)

    Musat, Florin; Wilkes, Heinz; Musat, Niculina; Kuypers, Marcel; Widdel, Friedrich

    2010-05-01

    Benzene, the archetypal aromatic hydrocarbon is a common constituent of crude oil and oil-refined products. As such, it can enter the biosphere through natural oil seeps or as a consequence of exploitation of fossil fuel reservoirs. Benzene is chemically very stable, due to the stabilizing aromatic electron system and to the lack of functional groups. Although the anaerobic degradation of benzene has been reported under denitrifying, sulfate-reducing and methanogenic conditions, the microorganisms involved and the initial biochemical steps of degradation remain insufficiently understood. Using marine sediment from a Mediterranean lagoon a sulfate-reducing enrichment culture with benzene as the sole organic substrate was obtained. Application of 16S rRNA gene-based methods showed that the enrichment was dominated (more than 85% of total cells) by a distinct phylotype affiliated with a clade of Deltaproteobacteria that include degraders of other aromatic hydrocarbons, such as naphthalene, ethylbenzene and m-xylene. Using benzoate as a soluble substrate in agar dilution series, several pure cultures closely related to Desulfotignum spp. and Desulfosarcina spp. were isolated. None of these strains was able to utilize benzene as a substrate and hybridizations with specific oligonucleotide probes showed that they accounted for as much as 6% of the total cells. Incubations with 13C-labeled benzene followed by Halogen in situ Hybridization - Secondary Ion Mass Spectroscopy (HISH-SIMS) analysis showed that cells of the dominant phylotype were highly enriched in 13C, while the accompanying bacteria had little or no 13C incorporation. These results demonstrate that the dominant phylotype was indeed the apparent benzene degrader. Dense-cell suspensions of the enrichment culture did not show metabolic activity toward added phenol or toluene, suggesting that benzene degradation did not proceed through anaerobic hydroxylation or methylation. Instead, benzoate was identified in

  20. An integrated approach to identify the influential priority of the factors governing anaerobic H2 production by mixed cultures.

    Science.gov (United States)

    Fang, Fang; Zeng, Raymond J; Sheng, Guo-Ping; Yu, Han-Qing

    2010-05-01

    An integrated approach incorporating response surface methodology, grey relational entropy, and fuzzy analytic hierarchy process is established to prioritize the influence of main factors governing the anaerobic H(2) production process and their influential priority. Response surface methodology is employed to design experiments, and the grey relational entropy is used to evaluate the influential grade of the three input factors, i.e., pH, temperature and initial substrate concentration (S(ini)), on the H(2) yield, maximum H(2) production rate and volatile fatty acid yield. In addition, through a combination of grey relational entropy, fuzzy analytic hierarchy process, which is used to determine the weight, and accelerating genetic algorithm, which is employed to minimize the nonlinear function in fuzzy analytic hierarchy process, the overall H(2) production process performance could be comprehensively evaluated. The results show that pH is the most important factor influencing the yields of H(2) and volatile fatty acids, while S(ini) has the most significant effect on the maximum H(2) production rate. Compared to pH and S(ini), temperature has a less important effect on the overall H(2) production reactor performance. This approach provides an appropriate way to identify the influential priority of input factors and to evaluate the overall performance for the anaerobic H(2) production process, and it can also be used for other complex biological and non-biological wastewater treatment systems. PMID:20347115

  1. In vitro activity of trovafloxacin against Bacteroides fragilis in mixed culture with either Escherichia coli or a vancomycin- resistant strain of Enterococcus faecium determined by an anaerobic time-kill technique.

    NARCIS (Netherlands)

    L.E.T. Stearne (Lorna); C. Kooi; W.H.F. Goessens (Wil); I.A.J.M. Bakker-Woudenberg (Irma); I.C. Gyssens (Inge)

    2001-01-01

    textabstractTo determine the efficacy of trovafloxacin as a possible treatment for intra-abdominal abscesses, we have developed an anaerobic time-kill technique using different inocula to study the in vitro killing of Bacteroides fragilis in pure culture or in mixed cul

  2. Legal Thinking on the Construction of Culture -Enriched Beijing%"人文北京"建设的法制思考

    Institute of Scientific and Technical Information of China (English)

    杨积堂

    2012-01-01

    The core of Culture - enriched Beijing construction lies in humanity and culture. From the perspec- tive of humanity, Culture - enriched Beijing construction aims to build up a more prosperous, civilized, harmoni- ous, livable and healthy socialist society. From the perspective of culture, Culture -enriched Beijing construction aims to build up the socialism with Chinese characteristics with the most humanistic concern, civilized and cultural charm capital. Legal construction is the significant aim and content requirement. For one thing, rule of law is one of content requirements to realize the real Culture - enriched Beijing. For another, perfecting the legal system is the fundamental guarantee in Culture -enriched Beijing construction. The perfect culture legal system, harmonious and efficient enforcement of cultural mechanism, uncorrupted judicial operation mechanism as well as convenient law intermediary service mechanism are the requirements of cultural legal construction. As for the legal system construc- tion, laying down the legal construction strategy, perfecting the local cultural code system and creating good legal atmosphere for Culture -enriched Beijing construction are proposed.%“人文北京”建设的核心是“人”和“文”,以人为本,以文化人,从“人”的角度,“人文北京”就是要建设更加繁荣、文明、和谐、宜居、健康的社会主义和谐社会“首善之区”。从“文”的角度.“人文北京”就是要建成最具人文关怀、最显文明风采、最有文化魅力的中国特色社会主义先进文化之都。“法治”建设,是人文北京建设的重要目标和内涵要求。一方面,法治是实现真正的“人文北京”的内涵之一;另一方面,健全法制又是“人文北京”建设的根本保障。完善的文化法律法规体系、协调高效的文化执法机制、廉洁公正的司法运行机制、便捷的法律中介服务机制是文化法制

  3. Hydrogen and lipid production from starch wastewater by co-culture of anaerobic sludge and oleaginous microalgae with simultaneous COD, nitrogen and phosphorus removal.

    Science.gov (United States)

    Ren, Hong-Yu; Liu, Bing-Feng; Kong, Fanying; Zhao, Lei; Ren, Nanqi

    2015-11-15

    Anaerobic sludge (AS) and microalgae were co-cultured to enhance the energy conversion and nutrients removal from starch wastewater. Mixed ratio, starch concentration and initial pH played critical roles on the hydrogen and lipid production of the co-culture system. The maximum hydrogen production of 1508.3 mL L(-1) and total lipid concentration of 0.36 g L(-1) were obtained under the optimized mixed ratio (algae:AS) of 30:1, starch concentration of 6 g L(-1) and initial pH of 8. The main soluble metabolites in dark fermentation were acetate and butyrate, most of which can be consumed in co-cultivation. When sweet potato starch wastewater was used as the substrate, the highest COD, TN and TP removal and energy conversion efficiencies reached 80.5%, 88.7%, 80.1% and 34.2%, which were 176%, 178%, 200% and 119% higher than that of the control group (dark fermentation), respectively. This research provided a novel approach and achieved efficient simultaneous energy recovery and nutrients removal from starch wastewater by the co-culture system. PMID:26364224

  4. 322份血培养阳性病原菌在需氧、厌氧瓶的检出率比较%Comparison of detection rates of 322 blood culture positive pathogens in aerobic and anaerobic bottles

    Institute of Scientific and Technical Information of China (English)

    陈玉莲; 徐涛; 李磊邦; 李景松; 李永赞

    2012-01-01

    OBJECTIVE To analyze the detection rates of blood culture-positive pathogens in the aerobic bottle and anaerobic bottle from Jul 2010 to Jul 2011. METHODS The culture and identification for the blood were performed with the United States BD 9050 automated blood culture system and French bio-Merieux ATBExpression automatic bacterial identification system. RESULTS Of 2700 blood culture specimens, 322 blood cultures were positive, the positive rate was 11. 9%, including gram-positive cocci (24. 5%), gram-positive bacilli (0. 6%), gram-negative cocci (0.3%), gram-negative bacilli (65.8%), anaerobic (2.0%), and fungi (6.8%); there were only 130 (40. 4%) positive blood cultures in aerobic bottle and 60 (18. 6%) positive blood cultures in anaerobic bottlei there were 132 (41. 0%} positive cultures in aerobic and anaerobic blood cultures. CONCLUSION Simultaneous culture with aerobic and anaerobic bottles for the same patient not only can fully reflect the rapidity of automatic blood culture system of rapid but also improve the positive rate of blood culture.%目的 分析2010年7月-2011年7月血培养阳性的病原菌在需氧、厌氧瓶检出率.方法 血培养及鉴定采用美国BD9050全自动血培养仪和法国生物梅里埃公司ATBExpression自动细菌鉴定仪.结果 在2700份血培养中阳性322份,阳性率为11.9%,其中革兰阳性球菌占24.5%、革兰阳性杆菌占0.6%、革兰阴性球菌占0.3%、革兰阴性杆菌占65.8%、厌氧菌占2.0%、真菌占6.8%;其中仅需氧血培养阳性130份,占40.4%,仅厌氧血培养阳性60份,占18.6%,需氧与厌氧血培养均阳性132份,占41.0%.结论 同一患者同时进行需氧瓶及厌氧瓶培养,即能充分体现自动血培养仪快速性,又能提高血培养阳性率.

  5. Anaerobic Process.

    Science.gov (United States)

    Yang, Qian; Ju, Mei-Ting; Li, Wei-Zun; Liu, Le; Wang, Yan-Nan; Chang, Chein-Chi

    2016-10-01

    A review of the literature published in 2015 on the focus of Anaerobic Process. It is divided into the following sections. Pretreatment Organic waste Multiple-stage co-digestion Process Methodology and Technology. PMID:27620085

  6. Anaerobic bacteria

    Science.gov (United States)

    Brook I, Goldstein EJ. Diseases caused by non-spore forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 297. Stedman's Online ...

  7. Phylogenetic and functional diversity within toluene-degrading, sulphate-reducing consortia enriched from a contaminated aquifer.

    Science.gov (United States)

    Kuppardt, Anke; Kleinsteuber, Sabine; Vogt, Carsten; Lüders, Tillmann; Harms, Hauke; Chatzinotas, Antonis

    2014-08-01

    Three toluene-degrading microbial consortia were enriched under sulphate-reducing conditions from different zones of a benzene, toluene, ethylbenzene and xylenes (BTEX) plume of two connected contaminated aquifers. Two cultures were obtained from a weakly contaminated zone of the lower aquifer, while one culture originated from the highly contaminated upper aquifer. We hypothesised that the different habitat characteristics are reflected by distinct degrader populations. Degradation of toluene with concomitant production of sulphide was demonstrated in laboratory microcosms and the enrichment cultures were phylogenetically characterised. The benzylsuccinate synthase alpha-subunit (bssA) marker gene, encoding the enzyme initiating anaerobic toluene degradation, was targeted to characterise the catabolic diversity within the enrichment cultures. It was shown that the hydrogeochemical parameters in the different zones of the plume determined the microbial composition of the enrichment cultures. Both enrichment cultures from the weakly contaminated zone were of a very similar composition, dominated by Deltaproteobacteria with the Desulfobulbaceae (a Desulfopila-related phylotype) as key players. Two different bssA sequence types were found, which were both affiliated to genes from sulphate-reducing Deltaproteobacteria. In contrast, the enrichment culture from the highly contaminated zone was dominated by Clostridia with a Desulfosporosinus-related phylotype as presumed key player. A distinct bssA sequence type with high similarity to other recently detected sequences from clostridial toluene degraders was dominant in this culture. This work contributes to our understanding of the niche partitioning between degrader populations in distinct compartments of BTEX-contaminated aquifers.

  8. Landfill Leachate as Enrichment Culture for Ammonia-Oxidizing Bacteria%利用垃圾渗滤液富集培养氨氧化菌

    Institute of Scientific and Technical Information of China (English)

    崔荣; 李金玲; 李凤德; 韩京龙

    2011-01-01

    Maintaining a certain amount of active ammonia-oxidizing bacteria (AOB) in activated sludge is essential for the biological nitrogen removal process. The addition of enriched AOB into activated sludge is an effective option to increase AOB population. To economically get enriched AOB and effectively treat landfill leachate, the feasibility of using landfill leachate as a culture for enriching AOB was examined. Leachate from the Yantai municipal landfill site was used as the culture, and returned sludge from the Xin' an River municipal sewage treatment plant A2/O process was used as seed sludge. The AOB were enriched by fed batch cultivation. The results showed that after four cultivation cycles, the population of cells in the enriched AOB was 5. 6 times higher than the original activated sludge. By adding 14.5% of enriched AOB after four cultivation cycles into the activated sludge, the ammonia oxidation rate increased by 65.4%, which confirmed that landfill leachate could be used as a culture for enriching AOB.%确保活性污泥中适当的氨氧化菌(AOB)的数量及活性对污水生物除氮过程至关重要,投加富集AOB是增加活性污泥中AOB浓度的方法之一.为了经济有效地获取富集的AOB并有效处理难降解的垃圾渗滤液,对利用垃圾渗滤液富集培养AOB的可行性进行了研究.采用烟台市生活垃圾填埋场的垃圾渗滤液作为培养基,利用辛安河污水处理厂A2/O工艺二沉池的回流污泥进行接种,通过更代方式富集培养AOB.结果显示:更代4次后,菌液中AOB的浓度增至原来的5.6倍;向活性污泥中投加14.5%的经过4次更代富集培养的AOB,氨氧化速率提高了65.4%,从而验证了利用垃圾渗滤液富集AOB是可行的.

  9. Transition of an Anaerobic Escherichia coli Culture to Aerobiosis: Balancing mRNA and Protein Levels in a Demand-Directed Dynamic Flux Balance Analysis.

    Directory of Open Access Journals (Sweden)

    Joachim von Wulffen

    Full Text Available The facultative anaerobic bacterium Escherichia coli is frequently forced to adapt to changing environmental conditions. One important determinant for metabolism is the availability of oxygen allowing a more efficient metabolism. Especially in large scale bioreactors, the distribution of oxygen is inhomogeneous and individual cells encounter frequent changes. This might contribute to observed yield losses during process upscaling. Short-term gene expression data exist of an anaerobic E. coli batch culture shifting to aerobic conditions. The data reveal temporary upregulation of genes that are less efficient in terms of energy conservation than the genes predicted by conventional flux balance analyses. In this study, we provide evidence for a positive correlation between metabolic fluxes and gene expression. We then hypothesize that the more efficient enzymes are limited by their low expression, restricting flux through their reactions. We define a demand that triggers expression of the demanded enzymes that we explicitly include in our model. With these features we propose a method, demand-directed dynamic flux balance analysis, dddFBA, bringing together elements of several previously published methods. The introduction of additional flux constraints proportional to gene expression provoke a temporary demand for less efficient enzymes, which is in agreement with the transient upregulation of these genes observed in the data. In the proposed approach, the applied objective function of growth rate maximization together with the introduced constraints triggers expression of metabolically less efficient genes. This finding is one possible explanation for the yield losses observed in large scale bacterial cultivations where steady oxygen supply cannot be warranted.

  10. Anaerobic oxidation of methane in grassland soils used for cattle husbandry

    Directory of Open Access Journals (Sweden)

    A. Bannert

    2012-10-01

    Full Text Available While the importance of anaerobic methane oxidation has been reported for marine ecosystems, the role of this process in soils is still questionable. Grasslands used as pastures for cattle overwintering show an increase in anaerobic soil micro-sites caused by animal treading and excrement deposition. Therefore, anaerobic potential methane oxidation activity of severely impacted soil from a cattle winter pasture was investigated in an incubation experiment under anaerobic conditions using 13C-labelled methane. We were able to detect a high microbial activity utilizing CH4 as nutrient source shown by the respiration of 13CO2. Measurements of possible terminal electron acceptors for anaerobic oxidation of methane were carried out. Soil sulfate concentrations were too low to explain the oxidation of the amount of methane added, but enough nitrate and iron(III were detected. However, only nitrate was consumed during the experiment. 13C-PLFA analyses clearly showed the utilization of CH4 as nutrient source mainly by organisms harbouring 16:1ω7 PLFAs. These lipids were also found as most 13C-enriched fatty acids by Raghoebarsing et al. (2006 after addition of 13CH4 to an enrichment culture coupling denitrification of nitrate to anaerobic oxidation of methane. This might be an indication for anaerobic oxidation of methane by relatives of "Candidatus Methylomirabilis oxyfera" in the investigated grassland soil under the conditions of the incubation experiment.

  11. Thermophilic Anaerobic Biodegradation of [14C]Lignin, [14C]Cellulose, and [14C]Lignocellulose Preparations

    OpenAIRE

    Benner, Ronald; Hodson, Robert E.

    1985-01-01

    Thermophilic (55°C) anaerobic enrichment cultures were incubated with [14C-lignin]lignocellulose, [14C-polysaccharide]lignocellulose, and kraft [14C]lignin prepared from slash pine, Pinus elliottii, and 14C-labeled preparations of synthetic lignin and purified cellulose. Significant but low percentages (2 to 4%) of synthetic and natural pine lignin were recovered as labeled methane and carbon dioxide during 60-day incubations, whereas much greater percentages (13 to 23%) of kraft lignin were ...

  12. In-Situ Anaerobic Biosurfactant Production Process For Remediation Of DNAPL Contamination In Subsurface Aquifers

    Science.gov (United States)

    Albino, J. D.; Nambi, I. M.

    2009-12-01

    Microbial Enhanced Oil Recovery (MEOR) and remediation of aquifers contaminated with hydrophobic contaminants require insitu production of biosurfactants for mobilization of entrapped hydrophobic liquids. Most of the biosurfactant producing microorganisms produce them under aerobic condition and hence surfactant production is limited in subsurface condition due to lack of oxygen. Currently bioremediation involves expensive air sparging or excavation followed by exsitu biodegradation. Use of microorganisms which can produce biosurfactants under anaerobic conditions can cost effectively expedite the process of insitu bioremediation or mobilization. In this work, the feasibility of anaerobic biosurfactant production in three mixed anaerobic cultures prepared from groundwater and soil contaminated with chlorinated compounds and municipal sewage sludge was investigated. The cultures were previously enriched under complete anaerobic conditions in the presence of Tetrachloroethylene (PCE) for more than a year before they were studied for biosurfactant production. Biosurfactant production under anaerobic conditions was simulated using two methods: i) induction of starvation in the microbial cultures and ii) addition of complex fermentable substrates. Positive result for biosurfactant production was not observed when the cultures were induced with starvation by adding PCE as blobs which served as the only terminal electron acceptor. However, slight reduction in interfacial tension was noticed which was caused by the adherence of microbes to water-PCE interface. Biosurfactant production was observed in all the three cultures when they were fed with complex fermentable substrates and surface tension of the liquid medium was lowered below 35 mN/m. Among the fermentable substrates tested, vegetable oil yielded highest amount of biosurfactant in all the cultures. Complete biodegradation of PCE to ethylene at a faster rate was also observed when vegetable oil was amended to the

  13. Identity of the Growth-Limiting Nutrient Strongly Affects Storage Carbohydrate Accumulation in Anaerobic Chemostat Cultures of Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Hazelwood, L.A.; Walsh, M.C.; Luttik, M.A.H.; Daran-Lapujade, P.; Pronk, J.T.; Daran, J.M.

    2009-01-01

    OA Fund TU Delft Accumulation of glycogen and trehalose in nutrient-limited cultures of Saccharomyces cerevisiae is negatively correlated with the specific growth rate. Additionally, glucose-excess conditions (i.e., growth limitation by nutrients other than glucose) are often implicated in high-lev

  14. Decolorization of azo dyes with high salt concentration by salt-tolerant mixed cultures under anaerobic conditions

    Institute of Scientific and Technical Information of China (English)

    GUO Jian-bo; ZHOU Ji-ti; WANG Dong; WANG Jing; YU Hui; SONG Zhi-yong

    2005-01-01

    Because the lack of detailed study of biological decolorization in high salt dye wastewater, it is still difficult to evaluate the biological treatment on high-salinity dye wastewater. The experiments were carried out to study the salt-tolerant bacteria, which is useful in the treatment of high-salinity colored wastewater. Simulated wastewater containing 5-150 g/L salt (NaCl) and 50-2000 mg/L Reactive Brilliant Red K-2BP was treated with three salt-tolerant mixed cultures (CAS, TAS, DSAS), which were under a gradually acclimated procedure. With the increase of concentrations of salt and dye, the decolorization became low. The abilities of decolorization of dyes wastewater by three mixed cultures (CAS, TAS, DSAS) were studied, CAS and DSAS mixed cultures showed more active for the treatment of high-salinity colored wastewater than TAS mixed cultures. The results suggested that there might be a simple process for the high salt wastewater treatment, which could be incorporated into conventional activated sludge plants.

  15. Anaerobic biotransformation of estrogens

    Energy Technology Data Exchange (ETDEWEB)

    Czajka, Cynthia P. [Department of Microbiology, University of Manitoba, Winnipeg, MB, R3T 2N2 (Canada); Londry, Kathleen L. [Department of Microbiology, University of Manitoba, Winnipeg, MB, R3T 2N2 (Canada)]. E-mail: londryk@cc.umanitoba.ca

    2006-08-31

    Estrogens are important environmental contaminants that disrupt endocrine systems and feminize male fish. We investigated the potential for anaerobic biodegradation of the estrogens 17-{alpha}-ethynylestradiol (EE2) and 17-{beta}-estradiol (E2) in order to understand their fate in aquatic and terrestrial environments. Cultures were established using lake water and sediment under methanogenic, sulfate-, iron-, and nitrate-reducing conditions. Anaerobic degradation of EE2 (added at 5 mg/L) was not observed in multiple trials over long incubation periods (over three years). E2 (added at 5 mg/L) was transformed to estrone (E1) under all four anaerobic conditions (99-176 {mu}g L{sup -1} day{sup -1}), but the extent of conversion was different for each electron acceptor. The oxidation of E2 to E1 was not inhibited by E1. Under some conditions, reversible inter-conversion of E2 and E1 was observed, and the final steady state concentration of E2 depended on the electron-accepting condition but was independent of the total amount of estrogens added. In addition, racemization occurred and E1 was also transformed to 17-{alpha}-estradiol under all but nitrate-reducing conditions. Although E2 could be readily transformed to E1 and in many cases 17-{alpha}-estradiol under anaerobic conditions, the complete degradation of estrogens under these conditions was minimal, suggesting that they would accumulate in anoxic environments.

  16. Fermentation and growth response of a primary poultry isolate of Salmonella typhimurium grown under strict anaerobic conditions in continuous culture and amino acid-limited batch culture.

    Science.gov (United States)

    Maciorowski, K G; Nisbet, D J; Ha, S D; Corrier, D E; DeLoach, J R; Ricke, S C

    1997-01-01

    Salmonella typhimurium is a significant hazard to consumer health that is carried asymptomatically in poultry gastrointestinal tracts. Nurmi cultures may prevent Salmonella colonization in young chicks, but the mechanism of competitive exclusion is unclear. Modeling Salmonella's metabolism in pure culture may allow for greater definition in choosing strains for Nurmi cultures. The growth rates and affinity constants of S. typhimurium growing in amino acid-limited conditions were determined in batch culture and compared to primary poultry isolates of cecal strains. Serine and NH4Cl were the best N sources for growth of all organisms tested in this study. The fermentation response of S. typhimurium was also monitored in continuous culture at a slow dilution rate of 0.021 h-1. S. typhimurium was found to adapt to VL media, with trends in protein disappearance, Yglucose, and Yprotein. This may show that amino acid or protein concentrations may be an integral component of the initial establishment of S. typhimurium in the cecum. PMID:9192013

  17. Fermentation and growth response of a primary poultry isolate of Salmonella typhimurium grown under strict anaerobic conditions in continuous culture and amino acid-limited batch culture.

    Science.gov (United States)

    Maciorowski, K G; Nisbet, D J; Ha, S D; Corrier, D E; DeLoach, J R; Ricke, S C

    1997-01-01

    Salmonella typhimurium is a significant hazard to consumer health that is carried asymptomatically in poultry gastrointestinal tracts. Nurmi cultures may prevent Salmonella colonization in young chicks, but the mechanism of competitive exclusion is unclear. Modeling Salmonella's metabolism in pure culture may allow for greater definition in choosing strains for Nurmi cultures. The growth rates and affinity constants of S. typhimurium growing in amino acid-limited conditions were determined in batch culture and compared to primary poultry isolates of cecal strains. Serine and NH4Cl were the best N sources for growth of all organisms tested in this study. The fermentation response of S. typhimurium was also monitored in continuous culture at a slow dilution rate of 0.021 h-1. S. typhimurium was found to adapt to VL media, with trends in protein disappearance, Yglucose, and Yprotein. This may show that amino acid or protein concentrations may be an integral component of the initial establishment of S. typhimurium in the cecum.

  18. Characterization of incubation experiments and development of an enrichment culture capable of ammonium oxidation under iron reducing conditions

    Science.gov (United States)

    Huang, S.; Jaffé, P. R.

    2014-08-01

    Incubation experiments were conducted using soil samples from a forested riparian wetland where we have previously observed anaerobic ammonium oxidation coupled to iron reduction. Production of both nitrite and ferrous iron were measured repeatedly during incubations when the soil slurry was supplied with either ferrihydrite or goethite and ammonium chloride. Significant changes in the microbial community were observed after 180 days of incubation as well as in a continuous flow membrane reactor, using 16S rRNA gene PCR-denaturing gradient gel electrophoresis, 454-pyrosequencing, and real-time quantitative PCR analysis. We believe that one of the dominant microbial species in our system (an uncultured Acidimicrobiaceae bacterium A6), belonging to the Acidimicrobiaceae family, whose closest cultivated relative is Ferrimicrobium acidiphilum (with 92% identity) and Acidimicrobium ferrooxidans (with 90% identity), might play a key role in this anaerobic biological process that uses ferric iron as an electron acceptor while oxidizing ammonium to nitrite. After ammonium was oxidized to nitrite, nitrogen loss proceeded via denitrification and/or anammox.

  19. Addition of novobiocin in pre-enrichment step can improve Salmonella culture protocol of modified semisolid Rappaport-Vassiliadis

    DEFF Research Database (Denmark)

    Jensen, Annette Nygaard; Sørensen, Gitte; Baggesen, Dorte Lau;

    2003-01-01

    -enrichment of 32 presumably naturally contaminated swine fecal samples were assessed for BPW with and without addition of Novobiocin (22 mug/ml). In another experiment, a total of 400 swine fecal samples were screened for the presence of Salmonella spp., in order to compare the performance of the nonselective pre...... be caused by a reduction in the number of competitive microorganisms....

  20. INTERMITTENT OPPORTUNITIES, SOME OBSERVATIONS AND HYPOTHESES RELATING TO AN EDUCATIONAL ENRICHMENT SUMMER PROGRAM FOR SOME CULTURALLY DEPRIVED CHILDREN OF BOSTON.

    Science.gov (United States)

    HOZID, JOSEPH L.

    THIS RESEARCH INVESTIGATED WHY DISADVANTAGED STUDENTS CHOSE TO ATTEND OR NOT TO ATTEND A SUMMER ENRICHMENT PROGRAM. INTERVIEWS WERE CONDUCTED WITH A SAMPLE OF GIRLS AND THEIR MOTHERS TO DETERMINE THE INFLUENCE OF SCHOOL AND FAMILY ON THEIR CHOICE. SOME OF THE SPECIFIC FACTORS AFFECTING THEIR ATTENDING WERE CONSIDERED IN PLANNING THE PROGRAM FOR…

  1. 中空纤维膜生物反应器富集反硝化厌氧甲烷氧化菌群的研究%Enrichment of denitrifying anaerobic methane oxidation microbes in a hollow fiber membrane bioreactor

    Institute of Scientific and Technical Information of China (English)

    钱祝胜; 付亮; 丁静; 丁兆威; 曾建雄

    2014-01-01

    反硝化厌氧甲烷氧化(DAMO)过程可以由一种称为Methylomirabilis oxy f era的DAMO细菌在有或者没有DAMO古菌下完成.已经报道的DAMO过程的菌群富集时间长(一般需要7~18月),且DAMO体系反硝化速率低.利用中空纤维膜生物反应器(HFMB)提高甲烷的传质来试图实现快速启动DAMO反应,结果发现HFMB在不到3个月时间内就表现出DAMO反应,其反硝化速率达到50 mg · L -1· d-1硝酸盐氮.二代测序显示,HFMB中微生物以 A naerolineaceae , A zospira ,CL500‐3占绝对优势,分别为39.08%,13.68%和11.54%,而 DAMO 细菌(Methylomirabilis)和与厌氧甲烷氧化有关的古菌 Methanosarcina分别占0.02%和0.13%,因此推测在HFMB中DAMO过程是由一群新的菌群主导完成.%The process of denitrifying anaerobic methane oxidation (DAMO) can be catalyzed by DAMO bacteria called Methylomirabilis oxyfera with or without the involvement of DAMO archaea .Enrichment of DAMO microbes often takes a long time (7 ~ 18 months) to show a faint denitrification function in reported DAMO process .This study aimed to fast enrich DAMO microbes in a hollow fiber membrane bioreactor (HFMB) as the special structure of hollow fiber can increase the mass transfer of methane .It is found that HFMB shows DAMO activity in a shorter period of time (<3 months) and the denitrification rate reaches 50 mg · L -1 · d-1 NO3 -‐N .The next‐generation DNA sequencing on the microbes in HFMB shows that Anaerolineaceae ,Azospira,CL500‐3 are dominant with 39.08% ,13.68% and 11.54% of the total microbes , respectively . Meanwhile , Methylomirabilis (DAMO bacteria ) and Methanosarcina (DAMO archaea) are only 0.02% and 0.13% ,respectively .It is speculated therefore that the DAMO process in HFMB may have been catalyzed by other microbes that are different from the known DAMO microbes .

  2. Comparative proteomic analysis of sulfur-oxidizing Acidithiobacillus ferrooxidans CCM 4253 cultures having lost the ability to couple anaerobic elemental sulfur oxidation with ferric iron reduction.

    Science.gov (United States)

    Kucera, Jiri; Sedo, Ondrej; Potesil, David; Janiczek, Oldrich; Zdrahal, Zbynek; Mandl, Martin

    2016-09-01

    In extremely acidic environments, ferric iron can be a thermodynamically favorable electron acceptor during elemental sulfur oxidation by some Acidithiobacillus spp. under anoxic conditions. Quantitative 2D-PAGE proteomic analysis of a resting cell suspension of a sulfur-grown Acidithiobacillus ferrooxidans CCM 4253 subculture that had lost its iron-reducing activity revealed 147 protein spots that were downregulated relative to an iron-reducing resting cell suspension of the antecedent sulfur-oxidizing culture and 111 that were upregulated. Tandem mass spectrometric analysis of strongly downregulated spots identified several physiologically important proteins that apparently play roles in ferrous iron oxidation, including the outer membrane cytochrome Cyc2 and rusticyanin. Other strongly repressed proteins were associated with sulfur metabolism, including heterodisulfide reductase, thiosulfate:quinone oxidoreductase and sulfide:quinone reductase. Transcript-level analyses revealed additional downregulation of other respiratory genes. Components of the iron-oxidizing system thus apparently play central roles in anaerobic sulfur oxidation coupled with ferric iron reduction in the studied microbial strain. PMID:27394989

  3. Outdoor cultures of Chlorella pyrenoidosa in the effluent of anaerobically digested activated sludge: The effects of pH and free ammonia.

    Science.gov (United States)

    Tan, Xiao-Bo; Zhang, Ya-Lei; Yang, Li-Bin; Chu, Hua-Qiang; Guo, Jun

    2016-01-01

    A freshwater algae Chlorella pyrenoidosa was cultured outdoors using anaerobically digested activated sludge effluent. The effects of pH variations were evaluated. The coupled pH variations and free ammonia toxicity significantly affected the algal growth, lipids accumulation and contamination control during every season. The free ammonia toxicity at high pH levels actually inhibited the algal growth. Compared to an optimal algal growth at a pH of 5.7-6.5, biomass productivity at a high pH of 8.3-8.8 was reduced by 67.15±6.98%, 54.39±6.42% and 83.63±5.71% in the spring, fall and summer, respectively. When the pH rose above 9.1-9.6, algae were unable to grow in the wastewater. However, high pH levels reduced contamination (e.g., bacteria and microalgae grazers) and triggered lipids accumulation in algal cells. These findings suggest that pH control strategies are essential for this type of algal wastewater system, where ammonia is the dominant nitrogen source. PMID:26547810

  4. Enrichment of Secondary Wastewater Sludge for Production of Hydrogen from Crude Glycerol and Comparative Evaluation of Mono-, Co- and Mixed-Culture Systems

    Directory of Open Access Journals (Sweden)

    Vinayak Laxman Pachapur

    2016-01-01

    Full Text Available Anaerobic digestion using mixed-culture with broader choice of pretreatments for hydrogen (H2 production was investigated. Pretreatment of wastewater sludge by five methods, such as heat, acid, base, microwave and chloroform was conducted using crude glycerol (CG as substrate. Results for heat treatment (100 °C for 15 min showed the highest H2 production across the pretreatment methods with 15.18 ± 0.26 mmol/L of medium at 30 °C in absence of complex media and nutrient solution. The heat-pretreated inoculum eliminated H2 consuming bacteria and produced twice as much as H2 as compared to other pretreatment methods. The fermentation conditions, such as CG concentration (1.23 to 24 g/L, percentage of inoculum size (InS (1.23% to 24% v/v along with initial pH (2.98 to 8.02 was tested using central composite design (CCD with H2 production as response parameter. The maximum H2 production of 29.43 ± 0.71 mmol/L obtained at optimum conditions of 20 g/L CG, 20% InS and pH 7. Symbiotic correlation of pH over CG and InS had a significant (p-value: 0.0011 contribution to H2 production. The mixed-culture possessed better natural acclimatization activity for degrading CG, at substrate inhibition concentration and provided efficient inoculum conditions in comparison to mono- and co-culture systems. The heat pretreatment step used across mixed-culture system is simple, cheap and industrially applicable in comparison to mono-/co-culture systems for H2 production.

  5. Enrichment of Secondary Wastewater Sludge for Production of Hydrogen from Crude Glycerol and Comparative Evaluation of Mono-, Co- and Mixed-Culture Systems.

    Science.gov (United States)

    Pachapur, Vinayak Laxman; Kutty, Prianka; Brar, Satinder Kaur; Ramirez, Antonio Avalos

    2016-01-13

    Anaerobic digestion using mixed-culture with broader choice of pretreatments for hydrogen (H₂) production was investigated. Pretreatment of wastewater sludge by five methods, such as heat, acid, base, microwave and chloroform was conducted using crude glycerol (CG) as substrate. Results for heat treatment (100 °C for 15 min) showed the highest H₂ production across the pretreatment methods with 15.18 ± 0.26 mmol/L of medium at 30 °C in absence of complex media and nutrient solution. The heat-pretreated inoculum eliminated H₂ consuming bacteria and produced twice as much as H₂ as compared to other pretreatment methods. The fermentation conditions, such as CG concentration (1.23 to 24 g/L), percentage of inoculum size (InS) (1.23% to 24% v/v) along with initial pH (2.98 to 8.02) was tested using central composite design (CCD) with H₂ production as response parameter. The maximum H₂ production of 29.43 ± 0.71 mmol/L obtained at optimum conditions of 20 g/L CG, 20% InS and pH 7. Symbiotic correlation of pH over CG and InS had a significant (p-value: 0.0011) contribution to H₂ production. The mixed-culture possessed better natural acclimatization activity for degrading CG, at substrate inhibition concentration and provided efficient inoculum conditions in comparison to mono- and co-culture systems. The heat pretreatment step used across mixed-culture system is simple, cheap and industrially applicable in comparison to mono-/co-culture systems for H₂ production.

  6. Enrichment of denitrifying methanotrophic bacteria from Taihu sediments by a membrane biofilm bioreactor at ambient temperature.

    Science.gov (United States)

    Wang, Shenghui; Wu, Qing; Lei, Ting; Liang, Peng; Huang, Xia

    2016-03-01

    Denitrification coupled to anaerobic methane oxidation is a recently discovered process performed by bacteria affiliated to the NC10 phylum. These microorganisms could play important roles in the energy-efficient way of anaerobic wastewater treatment where residual dissolved methane might be removed at the expense of nitrate or nitrite. The difficulty to enrich these microorganisms due to a slow growth rate, especially at low temperatures, limited its application in engineering field. In this study, an NC10 bacteria community was enriched from Taihu sediments by a membrane biofilm bioreactor at ambient temperature of 10-25 °C. After 13 months enrichment, the maximum denitrification rate of the enriched culture reached 0.54 mM day(-1) for nitrate and 1.06 mM day(-1) for nitrite. Anaerobic methane oxidation coupled denitrification was estimated from the (13)C-labeled CO2 ((13)CO2) production during batch incubations with (13)CH4. Furthermore, analysis of 16S rRNA genes clone library confirmed the presence of NC10 phylum bacteria and fluorescence in situ hybridization showed that NC10 bacteria dominated the reactor. All of the results indicated the NC10 bacteria community was competitive in terms of treating nitrate-contaminated water or wastewater under natural conditions. PMID:26578374

  7. Metabolism of reduced methylated sulfur compounds in anaerobic sediments and by a pure culture of an estuarine methanogen

    International Nuclear Information System (INIS)

    Addition of dimethylsulfide (DMS), dimethyldisulfide (DMDS), or methane thiol (MSH) to a diversity of anoxic aquatic sediments (e.g., fresh water, estuarine, alkaline/hypersaline) stimulated methane production. The yield of methane recovered from DMS was often 52 to 63%, although high concentrations of DMS (as well as MSH and DMDS) inhibited methanogenesis in some types of sediments. Production of methane from these reduced methylated sulfur compounds was blocked by 2-bromoethanesulfonic acid. Sulfate did not influence the metabolism of millimolar levels of DMS, DMDs, or MSH added to sediments. However, when DMS was added at ∼2-3=M levels as [14C]DMS, metabolism by sediments resulted in a 14CH4/14CO2 ratio of only 0.06. Addition of molybdate increased the ratio of 1.8, while 2-bromoethanesulfonic acid decreased it to 0, but did not block 14CO2 production. These results indicate the methanogens and sulfate reducers compete for DMS when it is present at low concentrations; however, at high concentrations, DMS is a noncompetitive substrate for methanogens. Metabolism of DMS by sediments resulted in the appearance of MSH as a transient intermediate. A pure culture of an obligately methylotrophic estuarine methanogen was isolated which was capable of growth on DMS. Metabolism of DMS by the culture also resulted in the transient appearance of MSH, but the organism could grow on neither MSH nor DMDS. The culture metabolized [14C]-DMS to yield a 14CH4/14CO2 ratio of ∼ 2.8

  8. Comparative Analysis of 16S rRNA and amoA Genes from Archaea Selected with Organic and Inorganic Amendments in Enrichment Culture

    OpenAIRE

    Xu, Mouzhong; Schnorr, Jon; Keibler, Brandon; Holly M Simon

    2012-01-01

    We took advantage of a plant-root enrichment culture system to characterize mesophilic soil archaea selected through the use of organic and inorganic amendments. Comparative analysis of 16S rRNA and amoA genes indicated that specific archaeal clades were selected under different conditions. Three amoA sequence clades were identified, while for a fourth group, identified by 16S rRNA gene analysis alone and referred to as the “root” clade, we detected no corresponding amoA gene. The amoA-contai...

  9. Anaerobic workout

    OpenAIRE

    McAdam, Ewan J.

    2010-01-01

    Anaerobic technology cannot directly replace current wastewater treatment processes exclusively. The UASB reactor configuration removes slightly less organic carbon by comparison as the process relies on lamella separation for passive clarification rather than using fine pores like anMBR. By contrast, whilst anMBR can operate as a single unit process for organic carbon removal, the membrane surface has to be cleaned using gas sparging to limit surface deposition, which requires extra energy. ...

  10. Techniques for controlling variability in gram staining of obligate anaerobes.

    OpenAIRE

    Johnson, M. J.; Thatcher, E; Cox, M E

    1995-01-01

    Identification of anaerobes recovered from clinical samples is complicated by the fact that certain gram-positive anaerobes routinely stain gram negative; Peptostreptococcus asaccharolyticus, Eubacterium plautii, Clostridium ramosum, Clostridium symbiosum, and Clostridium clostridiiforme are among the nonconformists with regard to conventional Gram-staining procedures. Accurate Gram staining of American Type Culture Collection strains of these anaerobic bacteria is possible by implementing fi...

  11. Changing anaerobic spectrum in suppurative lung disease: a case report.

    Science.gov (United States)

    Beena, V K; Kumari, G R; Rao, P V; Murty, M V; Shivananda, P G

    1996-01-01

    A spectrum of three different anaerobes were isolated from a debilitated patient with suppurative lung disease, within a two-year period. Repeated isolation from three consecutive samples and symptomatic relief with metronidazole provide clinical evidence of anaerobic lung infection. This case emphasizes the importance of anaerobic culture in cases of protracted pulmonary suppurative disease. PMID:8822645

  12. Bacterial Wound Culture

    Science.gov (United States)

    ... 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 ...

  13. A simple and sensitive quality control method of the anaerobic atmosphere for identification and antimicrobial susceptibility testing of anaerobic bacteria

    DEFF Research Database (Denmark)

    Justesen, Tage; Justesen, Ulrik Stenz

    2013-01-01

    The maintenance of a strict anaerobic atmosphere is essential for the culture of strict anaerobic bacteria. We describe a simple and sensitive quality control method of the anaerobic atmosphere, based on the measurement of the zone diameter around a 5-μg metronidazole disk when testing an...

  14. Complete genome sequence of Methylophilus sp. TWE2 isolated from methane oxidation enrichment culture of tap-water.

    Science.gov (United States)

    Xia, Fei; Zou, Bin; Shen, Cong; Zhu, Ting; Gao, Xin-Hua; Quan, Zhe-Xue

    2015-10-10

    The non-methane-utilizing methylotroph, Methylophilus sp. TWE2, was isolated from tap-water during the enrichment of methanotrophs with methane. The complete genome sequence of strain TWE2 showed that this bacterium may convert methanol to formaldehyde via catalysis of methanol dehydrogenase (MDH), after which formaldehyde would be assimilated to biomass through the ribulose monophosphate (RuMP) pathway or dissimilated via the tetrahydromethanopterin (H4MPT) pathway. The deficiency of glycolysis and the TCA cycle indicate that strain TWE2 may be an obligate methylotroph. This is the first complete genome sequence of the genus Methylophilus. PMID:26253961

  15. Anaerobic Oxidation of Methane Coupled to Nitrite Reduction by Halophilic Marine NC10 Bacteria.

    Science.gov (United States)

    He, Zhanfei; Geng, Sha; Cai, Chaoyang; Liu, Shuai; Liu, Yan; Pan, Yawei; Lou, Liping; Zheng, Ping; Xu, Xinhua; Hu, Baolan

    2015-08-15

    Anaerobic oxidation of methane (AOM) coupled to nitrite reduction is a novel AOM process that is mediated by denitrifying methanotrophs. To date, enrichments of these denitrifying methanotrophs have been confined to freshwater systems; however, the recent findings of 16S rRNA and pmoA gene sequences in marine sediments suggest a possible occurrence of AOM coupled to nitrite reduction in marine systems. In this research, a marine denitrifying methanotrophic culture was obtained after 20 months of enrichment. Activity testing and quantitative PCR (qPCR) analysis were then conducted and showed that the methane oxidation activity and the number of NC10 bacteria increased correlatively during the enrichment period. 16S rRNA gene sequencing indicated that only bacteria in group A of the NC10 phylum were enriched and responsible for the resulting methane oxidation activity, although a diverse community of NC10 bacteria was harbored in the inoculum. Fluorescence in situ hybridization showed that NC10 bacteria were dominant in the enrichment culture after 20 months. The effect of salinity on the marine denitrifying methanotrophic culture was investigated, and the apparent optimal salinity was 20.5‰, which suggested that halophilic bacterial AOM coupled to nitrite reduction was obtained. Moreover, the apparent substrate affinity coefficients of the halophilic denitrifying methanotrophs were determined to be 9.8 ± 2.2 μM for methane and 8.7 ± 1.5 μM for nitrite. PMID:26048927

  16. Pilot experiment on utilization of vegetable biomass in Umbria. Part 2. Anaerobic digestion of the wastes coming from the maintenance activity of the lake Trasimeno and the working of energetic cultures

    International Nuclear Information System (INIS)

    In this work the energetic exploitation has been assessed of the vegetable biomasses available in the region Umbria, derived both from the maintenance operation of Lake Trasimeno and energetic cultures. Biomethanation experiments have been carried out both on laboratory scale, by preparing anaerobic digestion tests in batch and in continuous, and on pilot scale, through the use of a 2000 litres digest or. Throughout the experiment the main chemical and physical process parameters have been monitored and the process efficiency assessed. The experimental values, measured for the anaerobic digestion process, have shown that both types of biomass can be very good substrated for the production of biogas. Their energetic re-use, when considering the broad and complex problems posed by breeding wastes disposal, could positively contribute to a rational sustainability scheme of the activities operating in the territory

  17. Anaerobic biodegradability of macropollutants

    DEFF Research Database (Denmark)

    Angelidaki, Irini

    2002-01-01

    A variety of test procedures for determination of anaerobic biodegradability has been reported. This paper reviews the methods developed for determination of anaerobic biodegradability of macro-pollutants. Anaerobic biodegradability of micro-pollutants is not included. Furthermore, factors import...

  18. Bringing the Past to the Present. : The use of tagging and storytelling for the enrichment of cultural heritage.

    NARCIS (Netherlands)

    Vliet, H.M.M. (Harry) van; Hekman, Erik

    2011-01-01

    The Internet’s dominant role in recent years has caused a change in the relationship between media producers, suppliers and consumers in the traditional media landscape. The cultural sector must therefore decide what to do with today’s digital media in response to the general public’s changing role,

  19. An enrichment and acclimation procedure to obtain photo heterotrophic cultures for H{sub 2} production from organic effluents

    Energy Technology Data Exchange (ETDEWEB)

    Acevedo-Benitez, J. A.; Ponce-Noyola, M. T.; Poggi-Varaldo, H. M.

    2009-07-01

    Production of H{sub 2} via photo heterotrophic is an attractive alternative, due to the capacity of photo heterotrophic organisms to convert the organic matter of effluents into H{sub 2}. The objective of our work was to develop a protocol for selecting undefined mixed cultures of photo heterotrophic microorganism with the capability of producing of H{sub 2}. (Author)

  20. ENRICHMENT AND CHARACTERIZATION OF THYMUS-REPOPULATING CELLS IN STROMA-DEPENDENT CULTURES OF RAT BONE-MARROW

    NARCIS (Netherlands)

    PRAKAPAS, Z; DENOYELLE, M; DARGEMONT, C; KROESE, FGM; THIERY, JP; DEUGNIER, MA

    1993-01-01

    The bone marrow precursor cells seeding the thymus have been difficult to investigate using fresh bone marrow and in vivo thymus reconstitution assays. We have therefore designed a short-term bone marrow culture system allowing the study of thymus-repopulating cells in the marrow microenvironment. L

  1. Anaerobic thermophiles.

    Science.gov (United States)

    Canganella, Francesco; Wiegel, Juergen

    2014-01-01

    The term "extremophile" was introduced to describe any organism capable of living and growing under extreme conditions. With the further development of studies on microbial ecology and taxonomy, a variety of "extreme" environments have been found and an increasing number of extremophiles are being described. Extremophiles have also been investigated as far as regarding the search for life on other planets and even evaluating the hypothesis that life on Earth originally came from space. The first extreme environments to be largely investigated were those characterized by elevated temperatures. The naturally "hot environments" on Earth range from solar heated surface soils and water with temperatures up to 65 °C, subterranean sites such as oil reserves and terrestrial geothermal with temperatures ranging from slightly above ambient to above 100 °C, to submarine hydrothermal systems with temperatures exceeding 300 °C. There are also human-made environments with elevated temperatures such as compost piles, slag heaps, industrial processes and water heaters. Thermophilic anaerobic microorganisms have been known for a long time, but scientists have often resisted the belief that some organisms do not only survive at high temperatures, but actually thrive under those hot conditions. They are perhaps one of the most interesting varieties of extremophilic organisms. These microorganisms can thrive at temperatures over 50 °C and, based on their optimal temperature, anaerobic thermophiles can be subdivided into three main groups: thermophiles with an optimal temperature between 50 °C and 64 °C and a maximum at 70 °C, extreme thermophiles with an optimal temperature between 65 °C and 80 °C, and finally hyperthermophiles with an optimal temperature above 80 °C and a maximum above 90 °C. The finding of novel extremely thermophilic and hyperthermophilic anaerobic bacteria in recent years, and the fact that a large fraction of them belong to the Archaea has definitely

  2. Anaerobic Thermophiles

    Directory of Open Access Journals (Sweden)

    Francesco Canganella

    2014-02-01

    Full Text Available The term “extremophile” was introduced to describe any organism capable of living and growing under extreme conditions. With the further development of studies on microbial ecology and taxonomy, a variety of “extreme” environments have been found and an increasing number of extremophiles are being described. Extremophiles have also been investigated as far as regarding the search for life on other planets and even evaluating the hypothesis that life on Earth originally came from space. The first extreme environments to be largely investigated were those characterized by elevated temperatures. The naturally “hot environments” on Earth range from solar heated surface soils and water with temperatures up to 65 °C, subterranean sites such as oil reserves and terrestrial geothermal with temperatures ranging from slightly above ambient to above 100 °C, to submarine hydrothermal systems with temperatures exceeding 300 °C. There are also human-made environments with elevated temperatures such as compost piles, slag heaps, industrial processes and water heaters. Thermophilic anaerobic microorganisms have been known for a long time, but scientists have often resisted the belief that some organisms do not only survive at high temperatures, but actually thrive under those hot conditions. They are perhaps one of the most interesting varieties of extremophilic organisms. These microorganisms can thrive at temperatures over 50 °C and, based on their optimal temperature, anaerobic thermophiles can be subdivided into three main groups: thermophiles with an optimal temperature between 50 °C and 64 °C and a maximum at 70 °C, extreme thermophiles with an optimal temperature between 65 °C and 80 °C, and finally hyperthermophiles with an optimal temperature above 80 °C and a maximum above 90 °C. The finding of novel extremely thermophilic and hyperthermophilic anaerobic bacteria in recent years, and the fact that a large fraction of them belong

  3. Isolation, Growth, and Metabolism of an Obligately Anaerobic, Selenate-Respiring Bacterium, Strain SES-3

    OpenAIRE

    Oremland, Ronald S.; Blum, Jodi Switzer; Culbertson, Charles W.; Visscher, Pieter T.; Miller, Laurence G.; Dowdle, Phillip; Strohmaier, Frances E.

    1994-01-01

    A gram-negative, strictly anaerobic, motile vibrio was isolated from a selenate-respiring enrichment culture. The isolate, designated strain SES-3, grew by coupling the oxidation of lactate to acetate plus CO2 with the concomitant reduction of selenate to selenite or of nitrate to ammonium. No growth was observed on sulfate or selenite, but cell suspensions readily reduced selenite to elemental selenium (Se0). Hence, SES-3 can carry out a complete reduction of selenate to Se0. Washed cell sus...

  4. Bacterial diversity of autotrophic enriched cultures from remote, glacial Antarctic, Alpine and Andean aerosol, snow and soil samples

    Directory of Open Access Journals (Sweden)

    E. González-Toril

    2009-01-01

    Full Text Available Four different communities and one culture of autotrophic microbial assemblages were obtained by incubation of samples collected from high elevation snow in the Alps (Mt. Blanc area and the Andes (Nevado Illimani summit, Bolivia, from Antarctic aerosol (French station Dumont d'Urville and a maritime Antarctic soil (King George Island, South Shetlands, Uruguay Station Artigas, in a minimal mineral (oligotrophic media. Molecular analysis of more than 200 16S rRNA gene sequences showed that all cultured cells belong to the Bacteria domain. Phylogenetic comparison with the currently available rDNA database allowed sequences belonging to Proteobacteria Alpha-, Beta- and Gamma-proteobacteria, Actinobacteria and Bacteroidetes phyla to be identified. The Andes snow culture was the richest in bacterial diversity (eight microorganisms identified and the marine Antarctic soil the poorest (only one. Snow samples from Col du Midi (Alps and the Andes shared the highest number of identified microorganisms (Agrobacterium, Limnobacter, Aquiflexus and two uncultured Alphaproteobacteria clones. These two sampling sites also shared four sequences with the Antarctic aerosol sample (Limnobacter, Pseudonocardia and an uncultured Alphaproteobacteriaclone. The only microorganism identified in the Antarctica soil (Brevundimonas sp. was also detected in the Antarctic aerosol. Most of the identified microorganisms had been detected previously in cold environments, marine sediments soils and rocks. Air current dispersal is the best model to explain the presence of very specific microorganisms, like those identified in this work, in environments very distant and very different from each other.

  5. Enhanced start-up of anaerobic facultatively autotrophic biocathodes in bioelectrochemical systems

    KAUST Repository

    Zaybak, Zehra

    2013-12-01

    Biocathodes in bioelectrochemical systems (BESs) can be used to convert CO2 into diverse organic compounds through a process called microbial electrosynthesis. Unfortunately, start-up of anaerobic biocathodes in BESs is a difficult and time consuming process. Here, a pre-enrichment method was developed to improve start-up of anaerobic facultatively autotrophic biocathodes capable of using cathodes as the electron donor (electrotrophs) and CO2 as the electron acceptor. Anaerobic enrichment of bacteria from freshwater bog sediment samples was first performed in batch cultures fed with glucose and then used to inoculate BES cathode chambers set at -0.4V (versus a standard hydrogen electrode; SHE). After two weeks of heterotrophic operation of BESs, CO2 was provided as the sole electron acceptor and carbon source. Consumption of electrons from cathodes increased gradually and was sustained for about two months in concert with a significant decrease in cathode chamber headspace CO2. The maximum current density consumed was -34±4mA/m2. Biosynthesis resulted in organic compounds that included butanol, ethanol, acetate, propionate, butyrate, and hydrogen gas. Bacterial community analyses based on 16S rRNA gene clone libraries revealed Trichococcus palustris DSM 9172 (99% sequence identity) as the prevailing species in biocathode communities, followed by Oscillibacter sp. and Clostridium sp. Isolates from autotrophic cultivation were most closely related to Clostridium propionicum (99% sequence identity; ZZ16), Clostridium celerecrescens (98-99%; ZZ22, ZZ23), Desulfotomaculum sp. (97%; ZZ21), and Tissierella sp. (98%; ZZ25). This pre-enrichment procedure enables simplified start-up of anaerobic biocathodes for applications such as electrofuel production by facultatively autotrophic electrotrophs. © 2013 Elsevier B.V.

  6. Enhanced start-up of anaerobic facultatively autotrophic biocathodes in bioelectrochemical systems.

    Science.gov (United States)

    Zaybak, Zehra; Pisciotta, John M; Tokash, Justin C; Logan, Bruce E

    2013-12-01

    Biocathodes in bioelectrochemical systems (BESs) can be used to convert CO2 into diverse organic compounds through a process called microbial electrosynthesis. Unfortunately, start-up of anaerobic biocathodes in BESs is a difficult and time consuming process. Here, a pre-enrichment method was developed to improve start-up of anaerobic facultatively autotrophic biocathodes capable of using cathodes as the electron donor (electrotrophs) and CO2 as the electron acceptor. Anaerobic enrichment of bacteria from freshwater bog sediment samples was first performed in batch cultures fed with glucose and then used to inoculate BES cathode chambers set at -0.4V (versus a standard hydrogen electrode; SHE). After two weeks of heterotrophic operation of BESs, CO2 was provided as the sole electron acceptor and carbon source. Consumption of electrons from cathodes increased gradually and was sustained for about two months in concert with a significant decrease in cathode chamber headspace CO2. The maximum current density consumed was -34 ± 4 mA/m(2). Biosynthesis resulted in organic compounds that included butanol, ethanol, acetate, propionate, butyrate, and hydrogen gas. Bacterial community analyses based on 16S rRNA gene clone libraries revealed Trichococcus palustris DSM 9172 (99% sequence identity) as the prevailing species in biocathode communities, followed by Oscillibacter sp. and Clostridium sp. Isolates from autotrophic cultivation were most closely related to Clostridium propionicum (99% sequence identity; ZZ16), Clostridium celerecrescens (98-99%; ZZ22, ZZ23), Desulfotomaculum sp. (97%; ZZ21), and Tissierella sp. (98%; ZZ25). This pre-enrichment procedure enables simplified start-up of anaerobic biocathodes for applications such as electrofuel production by facultatively autotrophic electrotrophs.

  7. Timeline of bio-hydrogen production by anaerobic digestion of biomass

    Directory of Open Access Journals (Sweden)

    Bernadette E. TELEKY

    2015-12-01

    Full Text Available Anaerobic digestion of biomass is a process capable to produce biohydrogen, a clean source of alternative energy. Lignocellulosic biomass from agricultural waste is considered a renewable energy source; therefore its utilization also contributes to the reduction of water, soil and air pollution. The study consists in five consecutive experiments designed to utilize anaerobic bacterial enrichment cultures originating from the Hungarian Lake, Hévíz. Wheat straw was used as complex substrate to produce hydrogen. The timeline evolution of hydrogen production was analyzed and modelled by two functions: Logistic and Boltzmann. The results proved that hydrogen production is significant, with a maximum of 0.24 mlN/ml and the highest hydrogen production occurs between the days 4-10 of the experiment.

  8. 34S/32S fractionation in sulfur cycles catalyzed by anaerobic bacteria

    Science.gov (United States)

    Fry, B.; Gest, H.; Hayes, J. M.

    1988-01-01

    Stable isotopic distributions in the sulfur cycle were studied with pure and mixed cultures of the anaerobic bacteria, Chlorobium vibrioforme and Desulfovibrio vulgaris. D. vulgaris and C. vibrioforme can catalyze three reactions constituting a complete anaerobic sulfur cycle: reduction of sulfate to sulfide (D. vulgaris), oxidation of sulfide to elemental sulfur (C. vibrioforme), and oxidation of sulfur to sulfate (C. vibrioforme). In all experiments, the first and last reactions favored concentration of the light 32S isotope in products (isotopic fractionation factor epsilon = -7.2 and -1.7%, respectively), whereas oxidation of sulfide favored concentration of the heavy 34S isotope in products (epsilon = +1.7%). Experimental results and model calculations suggest that elemental sulfur enriched in 34S versus sulfide may be a biogeochemical marker for the presence of sulfide-oxidizing bacteria in modern and ancient environments.

  9. Determination of the cause of the symptoms on yellow yam (Dioscorea cayenensis Lam.) leaf tissue and their eradication, enriching the culture medium and using techniques of meristem culture, thermo and chemotherapy on in vitro conditions

    International Nuclear Information System (INIS)

    Yams (Dioscorea spp) has been cultivated for exportation in Costa Rica, in North Huetar region. In vitro culture technique has been used for multiplying planting material for many advantages. However, cleaning of viruses that affect has been ineffective. Viruses such as: the potyvirus, potexvirus, cucumovirus . Methods like meristem culture, chemotherapy, thermotherapy and combinations of these have been used for the elimination of virus in plant species. The plants were evaluated in indexing assays, observing symptoms, serological methods and electron microscopy, among others. Other problems that have been affecting in vitro plant are deficient culture media in some nutrient. The presence of some abnormal characteristics in leaf tissue was determined whether have been caused by a virus or a nutritional deficiency in the culture medium. The presence of the virus has tried to find using ELISA and electron microscopy. Tests meristem culture, thermotherapy and chemotherapy have been made for the eradication of a possible virus; which have been assessed by observation of symptomatology and ELISA. The efficiency of the culture medium was evaluated to enrich it with nitrogen or excess iron. None of the suspected virus found in ELISA tests. Filaments are presumably viral particles were found through analysis of ultrastructure, as well as alterations in chloroplasts which indicated the presence of a pathogen or toxicity. Thermotherapy and chemotherapy with the concentration of 40 mg/L of ribavirin have been the most effective for the elimination of symptoms in virus eradication treatments. Assessments nutrient concentrations have shown that the differences between the various treatments used were undetectable. The symptoms presented were caused, according to the conclusions, by a virus which should preferably deal with thermotherapy. (author)

  10. Heavy metal incorporation in foraminiferal calcite: results from multi-element enrichment culture experiments with Ammonia tepida

    Directory of Open Access Journals (Sweden)

    G.-J. Reichart

    2010-08-01

    Full Text Available The incorporation of heavy metals into carbonate tests of the shallow water benthic foraminifer Ammonia tepida was investigated under controlled laboratory conditions. Temperature, salinity, and pH of the culture solutions were kept constant throughout the duration of this experiment, while trace metal concentrations were varied. Concentrations of Ni, Cu, and Mn were set 5-, 10-, and 20 times higher than levels found in natural North Sea water; for reference, a control experiment with pure filtered natural North Sea water was also analysed. The concentrations of Cu and Ni from newly grown chambers were determined by means of both μ-synchrotron XRF and Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA-ICP-MS. The results of both independent analytical techniques agreed within the analytical uncertainty. In general, the concentration of the analysed elements in the tests increased in line with their concentration in the culture solutions. Potential toxic and/or chemical competition effects might have resulted in the decreased incorporation of Ni and Cu into the calcite of the specimens exposed to the highest elemental concentrations. Mn incorporation exhibited large variability in the experiment with the 20-fold increased element concentrations, potentially due to antagonistic effects with Cu. The partition coefficients of Cu and Ni were calculated to be 0.14 ± 0.02 and 1.0 ± 0.5, respectively, whereas the partition coefficient of Mn was estimated to be least 2.4. These partition coefficients now open the way for reconstructing past concentrations for these elements in sea water.

  11. Mechanisms, Chemistry, and Kinetics of Anaerobic Biodegradation of cis-Dichloroethene and Vinyl Chloride

    Energy Technology Data Exchange (ETDEWEB)

    McCarty, P.L.; Spormann, A.M.

    2000-12-01

    Anaerobic biological processes can result in PCE and TCE destruction through conversion to cis-dichloroethene (cDCE) then to vinyl chloride (VC), and finally to ethene. Here, the chlorinated aliphatic hydrocarbons (CAHs) serve as electron acceptors in energy metabolism, requiring electron donors such as hydrogen from an external source. The purpose of this study was to learn more about the biochemistry of cDCE and VC conversion to ethene, to better understand the requirements for electron donors, and to determine factors affecting the rates of CAH degradation and organism growth. The biochemistry of reductive dehalogenation of VC was studied with an anaerobic mixed culture enriched on VC. In other studies on electron donor needs for dehalogenation of cDCE and VC, competition for hydrogen was found to occur between the dehalogenators and other microorganisms such as methanogens and homoacetogens in a benzoate-acclimated dehalogenating methanogenic mixed culture. Factors affecting the relative rates of destruction of the solvents and their intermediate products were evaluated. Studies using a mixed PCE-dehalogenating culture as well as the VC enrichment for biochemical studies suggested that the same species was involved in both cDCE and VC dechlorination, and that cDCE and VC competitively inhibited each other's dechlorination rate.

  12. Anaerobic mineralization of 2,4,6-tribromophenol to CO2 by a synthetic microbial community comprising Clostridium, Dehalobacter, and Desulfatiglans.

    Science.gov (United States)

    Li, Zhiling; Yoshida, Naoko; Wang, Aijie; Nan, Jun; Liang, Bin; Zhang, Chunfang; Zhang, Dongdong; Suzuki, Daisuke; Zhou, Xue; Xiao, Zhixing; Katayama, Arata

    2015-01-01

    Anaerobic mineralization of 2,4,6-tribromophenol (2,4,6-TBP) was achieved by a synthetic anaerobe community comprising a highly enriched culture of Dehalobacter sp. phylotype FTH1 acting as a reductive debrominator; Clostridium sp. strain Ma13 acting as a hydrogen supplier via glucose fermentation; and a novel 4-chlorophenol-degrading anaerobe, Desulfatiglans parachlorophenolica strain DS. 2,4,6-TBP was debrominated to phenol by the combined action of Ma13 and FTH1, then mineralized into CO2 by sequential introduction of DS, confirmed using [ring-(14)C(U)] phenol. The optimum concentrations of glucose, SO4(2-), and inoculum densities were 0.5 or 2.5mM, 1.0 or 2.5mM, and the densities equivalent to 10(4)copiesmL(-1) of the 16S rRNA genes, respectively. This resulted in the complete mineralization of 23μM 2,4,6-TBP within 35days (0.58μmolL(-1)d(-1)). Thus, using a synthetic microbial community of isolates or highly enriched cultures would be an efficient, optimizable, low-cost strategy for anaerobic bioremediation of halogenated aromatics.

  13. Anaerobic oxidation of methane : evaluation of alternative conditions

    NARCIS (Netherlands)

    Suarez Zuluaga, D.A.

    2015-01-01

    Microorganisms capable of performing anaerobic oxidation of methane (AOM) coupled to sulphate reduction have high doubling times which make their enrichment difficult. However, due to higher energy gain, they might be rapidly enriched using alternative electron acceptors. In chapter 2, it was shown

  14. Is Job Enrichment Really Enriching?

    OpenAIRE

    Robert D. Mohr; Cindy Zoghi

    2006-01-01

    This study uses a survey of Canadian workers with rich, matched data on job characteristics to examine whether “enriched” job design, with features like quality circles, feedback, suggestion programs, and task teams, affects job satisfaction. We identify two competing hypotheses on the relationship between enriched jobs and job satisfaction. The “motivation hypothesis,” implies that enrichment will generally increase satisfaction and the “intensification hypothesis,” implies that enrichment m...

  15. The social cost of coastal erosion. Using cultural theory to enrich the interpretation of stated preference data.

    Science.gov (United States)

    Kontogianni, A.; Tourkolias, C.; Vousdoukas, M.; Skourtos, M.

    2012-04-01

    Natural coastal processes are to a great extent modified by proximity to man-made structures. Engineered interventions, port facilities, housing and industrial infrastructure, all can increase the coastline fluctuations significantly relative to those along a long unobstructed coastline. As a consequence, coastlines are increasingly exposed to coastal erosion, a phenomenon defined as the encroachment of land by the sea after averaging over a period, which is sufficiently long to eliminate the impacts of weather, storm events and local sediment dynamics. In order to provide cost effective management of coastal erosion it is crucial to estimate both the benefits and costs associated with various management alternatives. The initiatives on Integrated Coastal Zone Manegment in Europe, but also the upcoming Marine Strategy Framwork Directive would benefit greatly from a proliferation of socioeconomic information to assist decision makers who must weigh the impacts of various types of coastal improvement and the cost of beach protection/restoration. In that spirit, the objective of the present research is to report the results of a survey undertaken in two resort beaches on the island of Lesvos (Greece), designed to estimate public preferences for avoiding coastal erosion. A mixed methodological approach is employed by combining an open-ended contingent valuation survey with cultural theory of risk perception. The empirical models to analyze individual choices of erosion control programs and the associated welfare measures are presented, followed by the discussion of model specification and estimation issues, and the results of the data analysis. Some concluding remarks are then presented. By choosing this approach we aim at improving our understanding of preference structure for avoiding public risk, accepted level of risk and perceptions thereof. The framework can also be used for assessing the social cost of extreme weather events such as storm surges in the coastal

  16. Uranium enrichment

    International Nuclear Information System (INIS)

    GAO was asked to address several questions concerning a number of proposed uranium enrichment bills introduced during the 100th Congress. The bill would have restructured the Department of Energy's uranium enrichment program as a government corporation to allow it to compete more effectively in the domestic and international markets. Some of GAO's findings discussed are: uranium market experts believe and existing market models show that the proposed DOE purchase of a $750 million of uranium from domestic producers may not significantly increase production because of large producer-held inventories; excess uranium enrichment production capacity exists throughout the world; therefore, foreign producers are expected to compete heavily in the United States throughout the 1990s as utilities' contracts with DOE expire; and according to a 1988 agreement between DOE's Offices of Nuclear Energy and Defense Programs, enrichment decommissioning costs, estimated to total $3.6 billion for planning purposes, will be shared by the commercial enrichment program and the government

  17. Enriching Number Knowledge

    Science.gov (United States)

    Mack, Nancy K.

    2011-01-01

    Exploring number systems of other cultures can be an enjoyable learning experience that enriches students' knowledge of numbers and number systems in important ways. It helps students deepen mental computation fluency, knowledge of place value, and equivalent representations for numbers. This article describes how the author designed her…

  18. Uranium enrichment

    International Nuclear Information System (INIS)

    Canada is the world's largest producer and exporter of uranium, most of which is enriched elsewhere for use as fuel in LWRs. The feasibility of a Canadian uranium-enrichment enterprise is therefore a perennial question. Recent developments in uranium-enrichment technology, and their likely impacts on separative work supply and demand, suggest an opportunity window for Canadian entry into this international market. The Canadian opportunity results from three particular impacts of the new technologies: 1) the bulk of the world's uranium-enrichment capacity is in gaseous diffusion plants which, because of their large requirements for electricity (more than 2000 kW·h per SWU), are vulnerable to competition from the new processes; 2) the decline in enrichment costs increases the economic incentive for the use of slightly-enriched uranium (SEU) fuel in CANDU reactors, thus creating a potential Canadian market; and 3) the new processes allow economic operation on a much smaller scale, which drastically reduces the investment required for market entry and is comparable with the potential Canadian SEU requirement. The opportunity is not open-ended. By the end of the century the enrichment supply industry will have adapted to the new processes and long-term customer/supplier relationships will have been established. In order to seize the opportunity, Canada must become a credible supplier during this century

  19. Anaerobe Tolerance to Oxygen and the Potentials of Anaerobic and Aerobic Cocultures for Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    M.T. Kato

    1997-12-01

    Full Text Available The anaerobic treatment processes are considered to be well-established methods for the elimination of easily biodegradable organic matter from wastewaters. Some difficulties concerning certain wastewaters are related to the possible presence of dissolved oxygen. The common belief is that anaerobes are oxygen intolerant. Therefore, the common practice is to use sequencing anaerobic and aerobic steps in separate tanks. Enhanced treatment by polishing off the residual biodegradable oxygen demand from effluents of anaerobic reactors, or the biodegradation of recalcitrant wastewater pollutants, usually requires sequenced anaerobic and aerobic bacteria activities. However, the combined activity of both bacteria can also be obtained in a single reactor. Previous experiments with either pure or mixed cultures showed that anaerobes can tolerate oxygen to a certain extent. The oxygen toxicity to methanogens in anaerobic sludges was quantified in batch experiments, as well as in anaerobic reactors. The results showed that methanogens have a high tolerance to oxygen. In practice, it was confirmed that dissolved oxygen does not constitute any detrimental effect on reactor treatment performance. This means that the coexistence of anaerobic and aerobic bacteria in one single reactor is feasible and increases the potentials of new applications in wastewater treatment

  20. CD133-enriched Xeno-Free human embryonic-derived neural stem cells expand rapidly in culture and do not form teratomas in immunodeficient mice

    Directory of Open Access Journals (Sweden)

    Daniel L. Haus

    2014-09-01

    Full Text Available Common methods for the generation of human embryonic-derived neural stem cells (hNSCs result in cells with potentially compromised safety profiles due to maintenance of cells in conditions containing non-human proteins (e.g. in bovine serum or on mouse fibroblast feeders. Additionally, sufficient expansion of resulting hNSCs for scaling out or up in a clinically relevant time frame has proven to be difficult. Here, we report a strategy that produces hNSCs in completely “Xeno-Free” culture conditions. Furthermore, we have enriched the hNSCs for the cell surface marker CD133 via magnetic sorting, which has led to an increase in the expansion rate and neuronal fate specification of the hNSCs in vitro. Critically, we have also confirmed neural lineage specificity upon sorted hNSC transplantation into the immunodeficient NOD-scid mouse brain. The future use or adaptation of these protocols has the potential to better facilitate the advancement of pre-clinical strategies from the bench to the bedside.

  1. Development and evaluation of a loop-mediated isothermal amplification assay combined with enrichment culture for rapid detection of very low numbers of Vibrio parahaemolyticus in seafood samples.

    Science.gov (United States)

    Di, Huiling; Ye, Lei; Neogi, Sucharit Basu; Meng, Hecheng; Yan, He; Yamasaki, Shinji; Shi, Lei

    2015-01-01

    The aim of this study was to develop and evaluate a rapid and effective method to detect Vibrio parahaemolyticus, a leading pathogen causing seafood-borne gastroenteritis. A newly designed loop-mediated isothermal amplification (LAMP) assay including a short enrichment period was optimized. This assay correctly detected all the target strains (n=61) but none of the non-target strains (n=34). Very low numbers of V. parahaemolyticus (2 colony forming unit (CFU) per gram of seafood) could be detected within 3 h and the minimum time of the whole assay was only 5 h. Comparative screening of various seafood samples (n=70) indicated that the LAMP assay is superior to polymerase chain reaction (PCR) and conventional culture methods because it is more rapid and less complex. This highly sensitive LAMP assay can be applicable as the method of choice in large-scale and rapid screening of seafood and environmental samples to detect V. parahaemolyticus strains. PMID:25744462

  2. Improved Anaerobic Fermentation of Wheat Straw by Alkaline Pre-Treatment and Addition of Alkali-Tolerant Microorganisms

    Directory of Open Access Journals (Sweden)

    Heike Sträuber

    2015-04-01

    Full Text Available The potential of two alkali-tolerant, lignocellulolytic environmental enrichment cultures to improve the anaerobic fermentation of Ca(OH2-pre-treated wheat straw was studied. The biomethane potential of pre-treated straw was 36% higher than that of untreated straw. The bioaugmentation of pre-treated straw with the enrichment cultures did not enhance the methane yield, but accelerated the methane production during the first week. In acidogenic leach-bed fermenters, a 61% higher volatile fatty acid (VFA production and a 112% higher gas production, mainly CO2, were observed when pre-treated instead of untreated straw was used. With one of the two enrichment cultures as the inoculum, instead of the standard inoculum, the VFA production increased by an additional 36% and the gas production by an additional 110%, again mainly CO2. Analysis of the microbial communities in the leach-bed processes revealed similar bacterial compositions in the fermenters with pre-treated straw, which developed independently of the used inoculum. It was suggested that the positive metabolic effects with the enrichment cultures observed in both systems were due to initial activities of the alkali-tolerant microorganisms tackling the alkaline conditions better than the standard inocula, whereas the latter dominated in the long term.

  3. Enrichment of the Cancer Stem Phenotype in Sphere Cultures of Prostate Cancer Cell Lines Occurs through Activation of Developmental Pathways Mediated by the Transcriptional Regulator ΔNp63α.

    Directory of Open Access Journals (Sweden)

    Roberto Portillo-Lara

    Full Text Available Cancer stem cells (CSC drive prostate cancer tumor survival and metastasis. Nevertheless, the development of specific therapies against CSCs is hindered by the scarcity of these cells in prostate tissues. Suspension culture systems have been reported to enrich CSCs in primary cultures and cell lines. However, the molecular mechanisms underlying this phenomenon have not been fully explored.We describe a prostasphere assay for the enrichment of CD133+ CSCs in four commercial PCa cell lines: 22Rv1, DU145, LNCaP, and PC3. Overexpression of CD133, as determined by flow cytometric analysis, correlated with an increased clonogenic, chemoresistant, and invasive potential in vitro. This phenotype is concordant to that of CSCs in vivo. Gene expression profiling was then carried out using the Cancer Reference panel and the nCounter system from NanoString Technologies. This analysis revealed several upregulated transcripts that can be further explored as potential diagnostic markers or therapeutic targets. Furthermore, functional annotation analysis suggests that ΔNp63α modulates the activation of developmental pathways responsible for the increased stem identity of cells growing in suspension cultures.We conclude that profiling the genetic mechanisms involved in CSC enrichment will help us to better understand the molecular pathways that underlie CSC pathophysiology. This platform can be readily adapted to enrich and assay actual patient samples, in order to design patient-specific therapies that are aimed particularly against CSCs.

  4. Anaerobic fungal populations

    International Nuclear Information System (INIS)

    The development of molecular techniques has greatly broadened our view of microbial diversity and enabled a more complete detection and description of microbial communities. The application of these techniques provides a simple means of following community changes, for example, Ishii et al. described transient and more stable inhabitants in another dynamic microbial system, compost. Our present knowledge of anaerobic gut fungal population diversity within the gastrointestinal tract is based upon isolation, cultivation and observations in vivo. It is likely that there are many species yet to be described, some of which may be non-culturable. We have observed a distinct difference in the ease of cultivation between the different genera, for example, Caecomyes isolates are especially difficult to isolate and maintain in vitro, a feature that is likely to result in the under representation of this genera in culture-based enumerations. The anaerobic gut fungi are the only known obligately anaerobic fungi. For the majority of their life cycles, they are found tightly associated with solid digesta in the rumen and/or hindgut. They produce potent fibrolytic enzymes and grow invasively on and into the plant material they are digesting making them important contributors to fibre digestion. This close association with intestinal digesta has made it difficult to accurately determine the amount of fungal biomass present in the rumen, with Orpin suggesting 8% contribution to the total microbial biomass, whereas Rezaeian et al. more recently gave a value of approximately 20%. It is clear that the rumen microbial complement is affected by dietary changes, and that the fungi are more important in digestion in the rumens of animals fed with high-fibre diets. It seems likely that the gut fungi play an important role within the rumen as primary colonizers of plant fibre, and so we are particularly interested in being able to measure the appearance and diversity of fungi on the plant

  5. Contribution of enrichments and resampling for sulfate reducing bacteria diversity assessment by high-throughput cultivation.

    Science.gov (United States)

    Colin, Yannick; Goñi-Urriza, Marisol; Caumette, Pierre; Guyoneaud, Rémy

    2015-03-01

    The development of new high-throughput cultivation methods aims to increase the isolation efficiency as compared to standard techniques that often require enrichment procedures to compensate the low microbial recovery. In the current study, estuarine sulfate-reducing bacteria were isolated using an anaerobic isolation procedure in 384-well microplates. Ninety-nine strains were recovered from initial sediments. Isolates were identified according to their partial 16S rRNA sequences and clustered into 13 phylotypes. Besides, the increase in species richness obtained through enrichments or resampling was investigated. Forty-four enrichment procedures were conducted and shifts in sulfate-reducing bacterial communities were investigated through dsrAB gene fingerprinting. Despite efforts in conducting numerous enrichment conditions only few of them were statistically different from initial sample. The cultural diversity obtained from 3 of the most divergent enrichments, as well as from resampled sediments equally contributed to raise the sulfate-reducing diversity up to 22 phylotypes. Enrichments (selection of metabolism) or resampling (transient populations and micro-heterogeneity) may still be helpful to assess new microbial phylotypes. Nevertheless, all the newly cultivated strains were all representatives of minor Operational Taxonomic Units and could eventually be recovered by maintaining high-throughput isolation effort from the initial sediments.

  6. Microbial diversity in methanogenic hydrocarbon-degrading enrichment cultures isolated from a water-flooded oil reservoir (Dagang oil field, China)

    Science.gov (United States)

    Jiménez, Núria; Cai, Minmin; Straaten, Nontje; Yao, Jun; Richnow, Hans H.; Krüger, Martin

    2015-04-01

    Microbial transformation of oil to methane is one of the main degradation processes taking place in oil reservoirs, and it has important consequences as it negatively affects the quality and economic value of the oil. Nevertheless, methane could constitute a recovery method of carbon from exhausted reservoirs. Previous studies combining geochemical and isotopic analysis with molecular methods showed evidence for in situ methanogenic oil degradation in the Dagang oil field, China (Jiménez et al., 2012). However, the main key microbial players and the underlying mechanisms are still relatively unknown. In order to better characterize these processes and identify the main microorganisms involved, laboratory biodegradation experiments under methanogenic conditions were performed. Microcosms were inoculated with production and injection waters from the reservoir, and oil or 13C-labelled single hydrocarbons (e.g. n-hexadecane or 2-methylnaphthalene) were added as sole substrates. Indigenous microbiota were able to extensively degrade oil within months, depleting most of the n-alkanes in 200 days, and producing methane at a rate of 76 ± 6 µmol day-1 g-1 oil added. They could also produce heavy methane from 13C-labeled 2-methylnaphthalene, suggesting that further methanogenesis may occur from the aromatic and polyaromatic fractions of Dagang reservoir fluids. Microbial communities from oil and 2-methyl-naphthalene enrichment cultures were slightly different. Although, in both cases Deltaproteobacteria, mainly belonging to Syntrophobacterales (e.g. Syntrophobacter, Smithella or Syntrophus) and Clostridia, mostly Clostridiales, were among the most represented taxa, Gammaproteobacteria could be only identified in oil-degrading cultures. The proportion of Chloroflexi, exclusively belonging to Anaerolineales (e.g. Leptolinea, Bellilinea) was considerably higher in 2-methyl-naphthalene degrading cultures. Archaeal communities consisted almost exclusively of representatives of

  7. Oxygen Effects in Anaerobic Digestion

    Directory of Open Access Journals (Sweden)

    Deshai Botheju

    2009-10-01

    Full Text Available Interaction of free oxygen in bio-gasification is a sparsely studied area, apart from the common argument of oxygen being toxic and inhibitory for anaerobic micro-cultures. Some studies have, however, revealed increased solubilisation of organic matter in the presence of some free oxygen in anaerobic digestion. This article analyses these counterbalancing phenomena with a mathematical modelling approach using the widely accepted biochemical model ADM 1. Aerobic oxidation of soluble carbon and inhibition of obligatory anaerobic organisms are modelled using standard saturation type kinetics. Biomass dependent first order hydrolysis kinetics is used to relate the increased hydrolysis rate with oxygen induced increase in biomass growth. The amended model, ADM 1-Ox (oxygen, has 25 state variables and 22 biochemical processes, presented in matrix form. The computer aided simulation tool AQUASIM 2.1 is used to simulate the developed model. Simulation predictions are evaluated against experimental data obtained using a laboratory batch test array comprising miniature anaerobic bio-reactors of 100 ml total volume each, operated under different initial air headspaces giving rise to the different oxygen loading conditions. The reactors were initially fed with a glucose solution and incubated at 35 Celsius, for 563 hours. Under the oxygen load conditions of 22, 44 and 88 mg/L, the ADM1-Ox model simulations predicted the experimental methane potentials quite adequately. Both the experimental data and the simulations suggest a linear reduction of methane potential with respect to the increase in oxygen load within this range.

  8. Biohydrogen production by anaerobic fermentation of waste. Final project report

    Energy Technology Data Exchange (ETDEWEB)

    Karakashev, D.; Angelidaki, I.

    2009-01-15

    The objective of this project was to investigate and increase dark fermentative hydrogen production from organic wastes by optimizing important process parameters (reactor type, pH, temperature, organic loading, retention time, inoculation strategy, microbial composition). Labscale experiments were carried out at the Department of Environmental Engineering, Technical University of Denmark. A two steps process for hydrogen production in the first step and methane production in the second step in serial connected fully mixed reactors was developed and could successfully convert organic matter to approx. 20-25 % hydrogen and 15-80 % to methane. Sparging with methane produced in the second stage could significantly increase the hydrogen production. Additionally it was shown that upflow anaerobic sludge blanket (UASB) reactor system was very promising for high effective biohydrogen production from glucose at 70 deg C. Glucose-fed biofilm reactors filled with plastic carriers demonstrated high efficient extreme thermophilic biohydrogen production with mixed cultures. Repeated batch cultivations via exposure of the cultures to increased concentrations of household solid waste was found to be most useful method to enhance hydrogen production rate and reduce lag phase of extreme thermophilic fermentation process. Low level of pH (5.5) at 3-day HRT was enough to inhibit completely the methanogenesis and resulted in stable extreme thermophilic hydrogen production. Homoacetogenisis was proven to be an alternative competitor to biohydrogen production from organic acids under thermophilic (55 deg. C) conditions. With respect to microbiology, 16S rRNA targeted oligonucleotide probes were designed to monitor the spatial distribution of hydrogen producing bacteria in sludge and granules from anaerobic reactors. An extreme thermophilic (70 deg. C), strict anaerobic, mixed microbial culture with high hydrogen producing potential was enriched from digested household waste. Culture

  9. Differential production of slime under aerobic and anaerobic conditions.

    OpenAIRE

    Barker, L P; Simpson, W A; Christensen, G D

    1990-01-01

    A series of 37 clinical isolates of coagulase-negative staphylococci previously identified as negative for slime production by the tube test were reexamined by the tissue culture plate test under aerobic and anaerobic conditions. None of the strains produced slime under anaerobic conditions; however, five strains (13%) produced slime under aerobic conditions.

  10. Job Enrichment

    Science.gov (United States)

    Sanders, Rick

    1970-01-01

    Job enrichment means giving people more decision-making power, more responsibility, more grasp of the totality of the job, and a sense of their own importance in the company. This article presents evidence of the successful working of this approach (Donnelly Mirrors), and the lack of success with an opposing approach (General Motors). (NL)

  11. A combined approach for the enhanced detection and isolation of Bartonella species in dog blood samples: pre-enrichment liquid culture followed by PCR and subculture onto agar plates.

    Science.gov (United States)

    Duncan, Ashlee W; Maggi, Ricardo G; Breitschwerdt, Edward B

    2007-05-01

    Historically, direct plating, lysis centrifugation, or freeze-thaw approaches have proven to be highly insensitive methods for confirming Bartonella species infection in dogs. A prospective study was designed to compare diagnostic methods for the detection of Bartonella using samples submitted to the Vector-Borne Disease Diagnostic Laboratory at North Carolina State University. Methods included indirect immunofluorescence assay, PCR, direct inoculation of a blood agar plate (trypticase soy agar with 5% rabbit blood), and inoculation into a novel pre-enrichment liquid medium, Bartonella/alpha-Proteobacteria growth medium (BAPGM). Sequential research efforts resulted in the development of a combinational approach consisting of pre-enrichment culture of Bartonella species in BAPGM, sub-inoculation of the liquid culture onto agar plates, followed by DNA amplification using PCR. The multi-faceted approach resulted in substantial improvement in the microbiological detection and isolation of Bartonella when compared to direct inoculation of a blood agar plate. Importantly, this approach facilitated the detection and subsequent isolation of both single and co-infections with two Bartonella species in the blood of naturally infected dogs. The use of a combinational approach of pre-enrichment culture and PCR may assist in the diagnostic confirmation of bartonellosis in dogs and other animals.

  12. The effects of co-contaminants and native wetland sediments on the activity and dominant transformation mechanisms of a 1,1,2,2-tetrachloroethane (TeCA)-degrading enrichment culture

    Science.gov (United States)

    Lorah, Michelle M.; Schiffmacher, Emily N.; Becker, Jennifer G.; Voytek, Mary A.

    2016-01-01

    Bioremediation strategies, including bioaugmentation with chlorinated ethene-degrading enrichment cultures, have been successfully applied in the cleanup of subsurface environments contaminated with tetrachloroethene (PCE) and/or trichloroethene (TCE). However, these compounds are frequently found in the environment as components of mixtures that may also contain chlorinated ethanes and methanes. Under these conditions, the implementation of bioremediation may be complicated by inhibition effects, particularly when multiple dehalorespirers are present. We investigated the ability of the 1,1,2,2-tetrachloroethane (TeCA)-dechlorinating culture WBC-2 to biotransform TeCA alone, or a mixture of TeCA plus PCE and carbon tetrachloride (CT), in microcosms. The microcosms contained electron donors provided to biostimulate the added culture and sediment collected from a wetland where numerous “hotspots” of contamination with chlorinated solvent mixtures exist. The dominant TeCA biodegradation mechanism mediated by the WBC-2 culture in the microcosms was different in the presence of these wetland sediments than in the sediment-free enrichment culture or in previous WBC-2 bioaugmented microcosms and column tests conducted with wetland sediment collected at nearby sites. The co-contaminants and their daughter products also inhibited TeCA biodegradation by WBC-2. These results highlight the need to conduct biodegradability assays at new sites, particularly when multiple contaminants and dehalorespiring populations are present.

  13. The effects of co-contaminants and native wetland sediments on the activity and dominant transformation mechanisms of a 1,1,2,2-tetrachloroethane (TeCA)-degrading enrichment culture.

    Science.gov (United States)

    Schiffmacher, Emily N; Becker, Jennifer G; Lorah, Michelle M; Voytek, Mary A

    2016-03-01

    Bioremediation strategies, including bioaugmentation with chlorinated ethene-degrading enrichment cultures, have been successfully applied in the cleanup of subsurface environments contaminated with tetrachloroethene (PCE) and/or trichloroethene (TCE). However, these compounds are frequently found in the environment as components of mixtures that may also contain chlorinated ethanes and methanes. Under these conditions, the implementation of bioremediation may be complicated by inhibition effects, particularly when multiple dehalorespirers are present. We investigated the ability of the 1,1,2,2-tetrachloroethane (TeCA)-dechlorinating culture WBC-2 to biotransform TeCA alone, or a mixture of TeCA plus PCE and carbon tetrachloride (CT), in microcosms. The microcosms contained electron donors provided to biostimulate the added culture and sediment collected from a wetland where numerous "hotspots" of contamination with chlorinated solvent mixtures exist. The dominant TeCA biodegradation mechanism mediated by the WBC-2 culture in the microcosms was different in the presence of these wetland sediments than in the sediment-free enrichment culture or in previous WBC-2 bioaugmented microcosms and column tests conducted with wetland sediment collected at nearby sites. The co-contaminants and their daughter products also inhibited TeCA biodegradation by WBC-2. These results highlight the need to conduct biodegradability assays at new sites, particularly when multiple contaminants and dehalorespiring populations are present. PMID:26766361

  14. Quick Enrichment & Acclimation of an Anaerobic Microbial Consortia Used for Biodegrading Teraphthalic Acid (TA)%降解对苯二甲酸厌氧微生物群快速驯化与富集技术

    Institute of Scientific and Technical Information of China (English)

    李小明; 陈坚; 伦世仪

    2000-01-01

    The seed sludge originated from a methane fermentation reactor was enriched and acclimated with TA as sole carbon source under nitrate respiration mode first, with 5.0g/L KNO3 being added in the first three weeks, 3.0g/L in the 4th, 0.4g/L in the 5th, and zero addition from the 6th and through another five weeks. After a total of 90 days for the enrichment and acclimation, the fermentative bacteria which originally existed in the seed sludge nearly disappeared, and instead of them, the TA reductive and cleaving bacteria group was formed in the new consortia, which was confirmed by the MPN counts and roll tube counts.%以TA为唯一碳源,在反硝化条件下对取自甲烷发酵反应器中的厌氧污泥进行驯化,最初的3周内,保持反应器中KNO3的浓度在5.0g/L,第四周降到3.0g/L,第五周降到0.4g/L,第六周起不添加KNO3再经过5周时间驯化.经过约90天的驯化,原存在于种污泥中的发酵性细菌几乎全部消亡,新的培养物中取而代之的是TA还原和开环菌.MPN计数和滚管计数进一步证实了上述结果.

  15. Anaerobic Metabolism and Bioremediation of Explosives-Contaminated Soil

    Science.gov (United States)

    Boopathy, Raj

    Nitroaromatic compounds pollute soil, water, and food via use of pesticides, plastics, pharmaceuticals, landfill dumping of industrial wastes, and the military use of explosives. Biotransformation of trinitrotoluene and other nitroaromatics by aerobic bacteria in the laboratory has been frequently reported, but the anaerobic bacterial metabolism of nitroaromatics has not been studied as extensively perhaps due to the difficulty in working with anaerobic cultures and the slow growth of anaerobes. Sulfate-reducing and methanogenic bacteria can metabolize nitroaromatic compounds under anaerobic conditions if appropriate electron donors and electron acceptors are present in the environment.

  16. Uranium enrichment

    International Nuclear Information System (INIS)

    This paper reports that in 1990 the Department of Energy began a two-year project to illustrate the technical and economic feasibility of a new uranium enrichment technology-the atomic vapor laser isotope separation (AVLIS) process. GAO believes that completing the AVLIS demonstration project will provide valuable information about the technical viability and cost of building an AVLIS plant and will keep future plant construction options open. However, Congress should be aware that DOE still needs to adequately demonstrate AVLIS with full-scale equipment and develop convincing cost projects. Program activities, such as the plant-licensing process, that must be completed before a plant is built, could take many years. Further, an updated and expanded uranium enrichment analysis will be needed before any decision is made about building an AVLIS plant. GAO, which has long supported legislation that would restructure DOE's uranium enrichment program as a government corporation, encourages DOE's goal of transferring AVLIS to the corporation. This could reduce the government's financial risk and help ensure that the decision to build an AVLIS plant is based on commercial concerns. DOE, however, has no alternative plans should the government corporation not be formed. Further, by curtailing a planned public access program, which would have given private firms an opportunity to learn about the technology during the demonstration project, DOE may limit its ability to transfer AVLIS to the private sector

  17. Gender comparisons in anaerobic power and anaerobic capacity tests.

    OpenAIRE

    Maud, P. J.; Shultz, B B

    1986-01-01

    The purpose of the study was to compare anaerobic power and anaerobic capacity test scores between young active men and women. Three performance measures of anaerobic power and two of anaerobic capacity were administered to a sample comprising 52 male and 50 female college students (means age = 21.4 yrs). Results indicated significant differences between men and women in body height, weight and per cent fat, in fat free mass (FFM), anaerobic power, and anaerobic capacity when recorded as gros...

  18. Potential enhancement of direct interspecies electron transfer for syntrophic metabolism of propionate and butyrate with biochar in up-flow anaerobic sludge blanket reactors.

    Science.gov (United States)

    Zhao, Zhiqiang; Zhang, Yaobin; Holmes, Dawn E; Dang, Yan; Woodard, Trevor L; Nevin, Kelly P; Lovley, Derek R

    2016-06-01

    Promoting direct interspecies electron transfer (DIET) to enhance syntrophic metabolism may be a strategy for accelerating the conversion of organic wastes to methane, but microorganisms capable of metabolizing propionate and butyrate via DIET under methanogenic conditions have yet to be identified. In an attempt to establish methanogenic communities metabolizing propionate or butyrate with DIET, enrichments were initiated with up-flow anaerobic sludge blanket (UASB), similar to those that were previously reported to support communities that metabolized ethanol with DIET that relied on direct biological electrical connections. In the absence of any amendments, microbial communities enriched were dominated by microorganisms closely related to pure cultures that are known to metabolize propionate or butyrate to acetate with production of H2. When biochar was added to the reactors there was a substantial enrichment on the biochar surface of 16S rRNA gene sequences closely related to Geobacter and Methanosaeta species known to participate in DIET. PMID:26967338

  19. Bacterial vaginosis with special reference to anaerobes

    Directory of Open Access Journals (Sweden)

    Sumati A

    2009-01-01

    Full Text Available Aims: This study was undertaken to assess the prevalence of bacterial vaginosis (BV and to estimate the prevalence of anaerobic organisms in vaginal discharge of women suffering from bacterial vaginosis. Settings and Design: Patients attending the Obstetrics and Gynecology Department of a Medical College Hospital. A one year cross-sectional study. Methods and Materials: High vaginal swabs taken from 174 female patients complaining of abnormal vaginal discharge. BV was diagnosed by clinical composite criteria and by gram stain. Anaerobes were isolated and identified from the discharge. Statistical Analysis Used: Chi square test, with level of significance set at a value of P< 0.05. Results: BV was diagnosed in 68.39% of the cases by using clinical composite criteria and in 58.4% of the cases by gram stain. Anaerobic culture isolation of vaginal swabs revealed that out of 174 cases 143 (82.65% were culture positive for anaerobes. Bacteroides were significantly raised in BV as compared with non bacterial vaginosis (NBV; < 0.05%. Conclusions: Anaerobic bacteria are important pathogens in the causation of bacterial vaginosis along with other aerobic organisms. Bacteroides and peptostreptococci are significantly raised in BV.

  20. The roles of the hybrid cluster protein, Hcp and its reductase, Hcr, in high affinity nitric oxide reduction that protects anaerobic cultures of Escherichia coli against nitrosative stress.

    Science.gov (United States)

    Wang, Jing; Vine, Claire E; Balasiny, Basema K; Rizk, John; Bradley, Charlene L; Tinajero-Trejo, Mariana; Poole, Robert K; Bergaust, Linda L; Bakken, Lars R; Cole, Jeffrey A

    2016-06-01

    The hybrid cluster protein, Hcp, contains a 4Fe-2S-2O iron-sulfur-oxygen cluster that is currently considered to be unique in biology. It protects various bacteria from nitrosative stress, but the mechanism is unknown. We demonstrate that the Escherichia coli Hcp is a high affinity nitric oxide (NO) reductase that is the major enzyme for reducing NO stoichiometrically to N2 O under physiologically relevant conditions. Deletion of hcp results in extreme sensitivity to NO during anaerobic growth and inactivation of the iron-sulfur proteins, aconitase and fumarase, by accumulated cytoplasmic NO. Site directed mutagenesis revealed an essential role in NO reduction for the conserved glutamate 492 that coordinates the hybrid cluster. The second gene of the hcp-hcr operon encodes an NADH-dependent reductase, Hcr. Tight interaction between Hcp and Hcr was demonstrated. Although Hcp and Hcr purified individually were inactive or when recombined, a co-purified preparation reduced NO in vitro with a Km for NO of 500 nM. In an hcr mutant, Hcp is reversibly inactivated by NO concentrations above 200 nM, indicating that Hcr protects Hcp from nitrosylation by its substrate, NO. PMID:26879449

  1. Rapid identification of Salmonella serovars in feces by specific detection of virulence genes, invA and spvC, by an enrichment broth culture-multiplex PCR combination assay.

    Science.gov (United States)

    Chiu, C H; Ou, J T

    1996-10-01

    In order to make a rapid and definite diagnosis of Salmonella enteritis in children, an enrichment broth culture-multiplex PCR combination assay was devised to identify Salmonella serovars directly from fecal samples. Two pairs of oligonucleotide primers were prepared according to the sequences of the chromosomal invA and plasmid spvC genes. PCR with these two primers would produce either one amplicon (from the invA gene) or two amplicons (from the invA and spvC genes), depending on whether or not the Salmonella bacteria contained a virulence plasmid. The fecal sample was diluted 10- to 20-fold into gram-negative enrichment broth and incubated to eliminate inhibitory compounds and also to allow selective enrichment of the bacteria. One or two amplicons were obtained, the expected result if Salmonella bacteria were present. The detection limit of this PCR was about 200 bacteria per reaction mixture. The primers were specific, as no amplification products were obtained with 18 species and 22 isolates of non-Salmonella bacteria tested which could be present in the feces or cause contamination. In contrast, when 23 commonly seen Salmonella serovars (38 isolates) were tested, all were shown to carry the invA gene and seven concomitantly harbored the spvC gene of the virulence plasmid. This assay was applied to the diagnosis of Salmonella enteritis in 57 children who were suffering from mucoid and/or bloody diarrhea. Of the 57 children, 38 were PCR positive and 22 were culture positive. There were two culture-positive samples that were not detected by PCR. Thus, this PCR assay showed an efficiency of 95% (38 of 40), which is much higher than the 60% (24 of 40) by culture alone. Not only is this method more sensitive, rapid, and efficient but it will cause only an incremental increase in the cost of stool processing, since enrichment cultivation of fecal samples from diarrheal patients using gram-negative enrichment broth is a routine practice for identification in many

  2. Combined Anaerobic-Aerobic Bacterial Degradation of Dyes

    OpenAIRE

    R. Wilfred Sugumar; Sandhya Sadanandan

    2010-01-01

    Wastewaters from the dye baths of a non-formal textile-dyeing unit containing C.I. Acid Orange 7 and C.I. Reactive Red 2 were subjected to degradation in a sequential anaerobic-aerobic treatment process based on mixed culture of bacteria. The technical samples of the dyestuffs and the dye bath wastes were treated in an anaerobic reactor, using an adapted mixed culture of anaerobic microorganisms. The dyestuffs were biotransformed into colourless substituted amine metabolites in the reactor. T...

  3. Anaerobic Digestion: Process

    DEFF Research Database (Denmark)

    Angelidaki, Irini; Batstone, Damien J.

    2011-01-01

    with very little dry matter may also be called a digest. The digest should not be termed compost unless it specifically has been composted in an aerated step. This chapter describes the basic processes of anaerobic digestion. Chapter 9.5 describes the anaerobic treatment technologies, and Chapter 9...

  4. Anaerobic sludge granulation

    NARCIS (Netherlands)

    Hulshoff Pol, L.W.; Castro Lopes, de S.I.; Lettinga, G.; Lens, P.N.L.

    2004-01-01

    This paper reviews different theories on anaerobic sludge granulation in UASB-reactors that have been proposed during the past two decades
    This paper reviews different theories on anaerobic sludge granulation in UASB-reactors that have been proposed during the past two decades. The initial stage

  5. 东南太平洋热液区硫化物样品富集培养物中Fe3+还原细菌的多样性分析%Diversity analysis of Fe3+ -reducing bacteria in enriched cultures from hydrothermal sulfide sample of southeast Pacific Ocean

    Institute of Scientific and Technical Information of China (English)

    秦丹; 张晓波; 姜丽晶; 盖英宝; 曾湘

    2011-01-01

    采集了东南太平洋热液区DY115-20V-S35-TVG17站位的沉积物硫化物样品,其含有76.717% (m/m)强还原性的磁性良好的黄铁矿.以乳酸钠为电子供体,不溶性的氢氧化铁为电子受体,对该样品进行Fe3+还原细菌的定向富集培养.通过构建该菌群的16S rDNA基因文库,随机挑选82个阳性克隆子进行群落结构多样性分析.研究结果表明:82个克隆代表的6种基因型分别属于4个主要类群,其中ε-变形杆菌占有绝对优势,达到55.2%.此外其还包括厚壁菌门、β-变形杆菌和α-变形杆菌,克隆子比例依次为27.6%、10.3%、6.9%.在富集产物中还原氢氧化铁的功能菌群主要是具有硫还原作用的ε-变形菌中的硫还原菌.%The ocean contains rich resources and in deep sea sediments there exists iron compounds at different stages of oxidation and reduction. Iron is one of the most widely distributed elements on the earth and its cycle chiefly includes two processes of oxidation and reduction. As a primitive form of respiration, Fe3 + -reduction and Fe3 + -reducing bacteria play an important role in the iron cycle where in sediments with an anaerobic environment, where iron chiefly exists in a reduced form. In the current study, a hydrothermal sulfide sample was obtained from the southeast Pacific Ocean, site DY115-20V-S35-TVG17 (50.648 l°N,37.780 2°W, depth 2 783 m) using a television grasp sampler in December, 2008, and was found to be mainly composed of iron pyrite with good magnetism, chiefly Fe1-XS and FeS2, 76.717% (m/m) through X-ray detection. To investigate the diversity of Fe3 +-reducing bacteria in the sample, we designed a medium with sodium lactate as the electron donor and insoluble ferric hydroxide as electron acceptor and cultivated the enriched culture of Fe3 +-reducing bacteria from this sample. The 16S Rdna gene library showed that the 29 selected clones in enriched cultures were clustered into two groups. Pro

  6. Multiplex Real-Time PCR Assays for Screening of Shiga Toxin 1 and 2 Genes, Including All Known Subtypes, and Escherichia coli O26-, O111-, and O157-Specific Genes in Beef and Sprout Enrichment Cultures.

    Science.gov (United States)

    Harada, Tetsuya; Iguchi, Atsushi; Iyoda, Sunao; Seto, Kazuko; Taguchi, Masumi; Kumeda, Yuko

    2015-10-01

    Shiga toxin family members have recently been classified using a new nomenclature into three Stx1 subtypes (Stx1a, Stx1c, and Stx1d) and seven Stx2 subtypes (Stx2a, Stx2b, Stx2c, Stx2d, Stx2e, Stx2f, and Stx2g). To develop screening methods for Stx genes, including all of these subtype genes, and Escherichia coli O26-, O111-, and O157-specific genes in laboratory investigations of Shiga toxin-producing E. coli (STEC) foodborne cases, we developed multiplex real-time PCR assays and evaluated their specificity and quantitative accuracy using STEC and non-STEC isolates, recombinant plasmids, and food enrichment cultures and by performing STEC spiking experiments with beef and sprout enrichment cultures. In addition, we evaluated the relationship between the recovery rates of the target strains by direct plating and immunomagnetic separation and the cycle threshold (CT) values of the real-time PCR assays for the Stx subtypes and STEC O26, O111, and O157 serogroups. All three stx1- and seven stx2-subtype genes were detected by real-time PCR with high sensitivity and specificity, and the quantitative accuracy of this assay was confirmed using control plasmids and STEC spiking experiments. The results of the STEC spiking experiments suggest that it is not routinely possible to isolate STEC from enrichment cultures with real-time PCR CT values greater than 30 by direct plating on MacConkey agar, although highly selective media and immunomagnetic beads were able to isolate the inoculated strains from the enrichment cultures. These data suggest that CT values obtained from the highly quantitative real-time PCR assays developed in this study provide useful information to develop effective isolation strategies for STEC from food samples. The real-time PCR assays developed here are expected to aid in investigations of infections or outbreaks caused by STEC harboring any of the stx-subtype genes in the new Stx nomenclature, as well as STEC O26, O111, and O157.

  7. Anaerobic Digestion and its Applications

    Science.gov (United States)

    Anaerobic digestion is a natural biological process. The initials "AD" may refer to the process of anaerobic digestion, or the built systems of anaerobic digesters. While there are many kinds of digesters, the biology is basically the same for all. Anaerobic digesters are built...

  8. Anaerobic infections in the head and neck region.

    Science.gov (United States)

    Tabaqchali, S

    1988-01-01

    Anaerobic bacteria form the predominant flora of the oral cavity, outnumbering facultative organisms by 10-1,000: 1. The type of anaerobic bacteria and their concentration depend on the anatomical site and the degree of anaerobiosis in the different sites in the mouth. Three groups of anaerobic bacteria inhabit the oral cavity; the strict anaerobes, the moderate anaerobes, and the microaerophilic group of organisms. The majority of anaerobic bacterial infections occurring in the region of the mouth, head and neck are caused by the commensal flora. These infections include dental and periodontal disease where the predominant organisms are Bacteroides species, Veillonella, Bifidobacteria, Peptococcus, Peptostreptococcus and Propionibacterium species. More recently, Bacteroides endontalis has been isolated from a periapical abscess of endodontal origin and B. gingivalis, B. intermedius, Haemophilus actinomycetemcomitans and Wollinella species in chronic periodontal disease. Treponema species and other strict anaerobes are seen in smears of severe periodontal disease and acute necrotising gingivitis, but have not yet been isolated in pure culture. Until such time, their role in disease remains uncertain. Fusobacterium nucleatum is specially associated with severe orofacial infections which may extend into the mediastinum. Other anaerobic infections include chronic otitis media, chronic sinusitis and mastoiditis, and brain abscess. Treatment of these conditions should include the use of beta-lactamase resistant antimicrobials, such as clindamycin or one of the nitroimidazoles with penicillin.

  9. The anaerobic degradation of gaseous, nonmethane alkanes — From in situ processes to microorganisms

    Directory of Open Access Journals (Sweden)

    Florin Musat

    2015-01-01

    Full Text Available The short chain, gaseous alkanes ethane, propane, n- and iso-butane are released in significant amounts into the atmosphere, where they contribute to tropospheric chemistry and ozone formation. Biodegradation of gaseous alkanes by aerobic microorganisms, mostly bacteria and fungi isolated from terrestrial environments, has been known for several decades. The first indications for short chain alkane anaerobic degradation were provided by geochemical studies of deep-sea environments around hydrocarbon seeps, and included the uncoupling of the sulfate-reduction and anaerobic oxidation of methane rates, the consumption of gaseous alkanes in anoxic sediments, or the enrichment in 13C of gases in interstitial water vs. the source gas. Microorganisms able to degrade gaseous alkanes were recently obtained from deep-sea and terrestrial sediments around hydrocarbon seeps. Up to date, only sulfate-reducing pure or enriched cultures with ethane, propane and n-butane have been reported. The only pure culture presently available, strain BuS5, is affiliated to the Desulfosarcina–Desulfococcus cluster of the Deltaproteobacteria. Other phylotypes involved in gaseous alkane degradation have been identified based on stable-isotope labeling and whole-cell hybridization. Under anoxic conditions, propane and n-butane are activated similar to the higher alkanes, by homolytic cleavage of the CH bond of a subterminal carbon atom, and addition of the ensuing radical to fumarate, yielding methylalkylsuccinates. An additional mechanism of activation at the terminal carbon atoms was demonstrated for propane, which could in principle be employed also for the activation of ethane.

  10. Methane and hydrogen production by human intestinal anaerobic bacteria.

    Science.gov (United States)

    McKay, L F; Holbrook, W P; Eastwood, M A

    1982-06-01

    The gas above liquid cultures of a variety of human intestinal anaerobic bacteria was sampled and analysed by headspace gas chromatography. Hydrogen production was greatest with strains of the genus Clostridium, intermediate with anaerobic cocci and least with Bacteroides sp. Very few strains produced methane although small amounts were detected with one strain of B. thetaiotaomicron, C. perfringens and C. histolyticum. There may be a relationship between these anaerobic bacteria and several gastrointestinal disorders in which there is a build up of hydrogen or methane in the intestines.

  11. Microbiological Hydrogen Production by Anaerobic Fermentation and Photosynthetic Process

    Energy Technology Data Exchange (ETDEWEB)

    Asada, Y.; Ohsawa, M.; Nagai, Y.; Fukatsu, M.; Ishimi, K.; Ichi-ishi, S.

    2009-07-01

    Hydrogen gas is a clean and renewable energy carrier. Microbiological hydrogen production from glucose or starch by combination used of an anaerobic fermenter and a photosynthetic bacterium, Rhodobacter spheroides RV was studied. In 1984, the co-culture of Clostridium butyricum and RV strain to convert glucose to hydrogen was demonstrated by Miyake et al. Recently, we studied anaerobic fermentation of starch by a thermophilic archaea. (Author)

  12. Taurine reduction in anaerobic respiration of Bilophila wadsworthia RZATAU.

    Science.gov (United States)

    Laue, H; Denger, K; Cook, A M

    1997-05-01

    Organosulfonates are important natural and man-made compounds, but until recently (T. J. Lie, T. Pitta, E. R. Leadbetter, W. Godchaux III, and J. R. Leadbetter. Arch. Microbiol. 166:204-210, 1996), they were not believed to be dissimilated under anoxic conditions. We also chose to test whether alkane- and arenesulfonates could serve as electron sinks in respiratory metabolism. We generated 60 anoxic enrichment cultures in mineral salts medium which included several potential electron donors and a single organic sulfonate as an electron sink, and we used material from anaerobic digestors in communal sewage works as inocula. None of the four aromatic sulfonates, the three unsubstituted alkanesulfonates, or the N-sulfonate tested gave positive enrichment cultures requiring both the electron donor and electron sink for growth. Nine cultures utilizing the natural products taurine, cysteate, or isethionate were considered positive for growth, and all formed sulfide. Two clearly different pure cultures were examined. Putative Desulfovibrio sp. strain RZACYSA, with lactate as the electron donor, utilized sulfate, aminomethanesulfonate, taurine, isethionate, and cysteate, converting the latter to ammonia, acetate, and sulfide. Strain RZATAU was identified by 16S rDNA analysis as Bilophila wadsworthia. In the presence of, e.g., formate as the electron donor, it utilized, e.g., cysteate and isethionate and converted taurine quantitatively to cell material and products identified as ammonia, acetate, and sulfide. Sulfite and thiosulfate, but not sulfate, were utilized as electron sinks, as was nitrate, when lactate was provided as the electron donor and carbon source. A growth requirement for 1,4-naphthoquinone indicates a menaquinone electron carrier, and the presence of cytochrome c supports the presence of an electron transport chain. Pyruvate-dependent disappearance of taurine from cell extracts, as well as formation of alanine and release of ammonia and acetate, was

  13. Exploring the potential of anaerobic sulfate reduction process in treating sulfonated diazo dye: Microbial community analysis using bar-coded pyrosequencing.

    Science.gov (United States)

    Rasool, Kashif; Shahzad, Asif; Lee, Dae Sung

    2016-11-15

    Anaerobic decolorization and biotransformation of azo dye was investigated in a sulfate-reducing environment. Batch reactor studies were performed with mixed cultures of anaerobic sulfate-reducing bacteria (SRBs) enriched from anaerobic digester sludge. Complete sulfate and color removal were achieved in batch experiments with different initial dye concentrations (50-2500mg/L) and 1000mg/L of sulfate. Induction of various oxidoreductive enzyme activities such as phenol oxidase, veratryl alcohol oxidase, lignin peroxidase, and azo reductase was studied to understand their involvement in dye metabolism under anoxic environment. The degradation of Cotton Red B was confirmed using high-performance liquid chromatography and gas chromatography-mass spectroscopy. Sulfidogenic sludge demonstrated excellent dye degradation and mineralization ability, producing aniline and 1,4-diamino benzene as metabolites. A barcoded 16S rRNA gene-pyrosequencing approach was used to assess the bacterial diversity in the sludge culture and a phylogenetic tree was constructed for sulfate-reducing bacteria. PMID:27475462

  14. Metagenomic analysis of denitrifying wastewater enrichment cultures able to transform the explosive, 3-nitro-1,2,4-triazol-5-one (NTO).

    Science.gov (United States)

    Eberly, Jed O; Indest, Karl J; Hancock, Dawn E; Jung, Carina M; Crocker, Fiona H

    2016-06-01

    Removal of 3-nitro-1,2,4-triazol-5-one (NTO) was investigated in conjunction with heterotrophic and autotrophic denitrifying growth conditions by a microbial consortium from a wastewater treatment plant. Microcosms were supplemented with molasses, methanol, or thiosulfate. Cultures were passaged twice by transferring 10 % of the culture volume to fresh media on days 11 and 21. Rates of NTO removal were 18.71 ± 0.65, 9.04 ± 2.61, and 4.34 ± 2.72 mg/L/day while rates of nitrate removal were 20.08 ± 1.13, 21.58 ± 1.20, and 24.84 ± 1.26 mg/L/day, respectively, for molasses, methanol, or thiosulfate. Metagenomic analysis showed that Proteobacteria and Firmicutes were the major phyla in the microbial communities. In molasses supplemented cultures, the community profile at the family level changed over time with Pseudomonadaceae the most abundant (67.4 %) at day 11, Clostridiaceae (65.7 %) at day 21, and Sporolactobacillaceae (35.4 %) and Clostridiaceae (41.0 %) at day 29. Pseudomonadaceae was the dominant family in methanol and thiosulfate supplemented cultures from day 21 to 29 with 76.6 and 81.6 % relative abundance, respectively. PMID:27033535

  15. ISOLATION OF ANAEROBES IN DEEP SEATED PRESSURE ULCERS USING A NOVEL INNOVATIVE TECHNIQUE OF ANAEROBE ISOLATION

    Directory of Open Access Journals (Sweden)

    Lalbiaktluangi

    2015-12-01

    Full Text Available BACKGROUND Isolation of an anaerobe is usually neglected in hospitals with limited resources due to the expensive and complicated technique of anaerobic isolation methods, which is difficult to arrange in such resource poor settings. Conventionally adopted anaerobic culture methods such as Anaerobic jar, Gas-Pak, Anoxomat or Automated glove-box systems are extremely costly and cumbersome for single unit testing, but not suitable for small scale laboratories. However, anaerobic bacteria are not to be overlooked as they have made a comeback in clinical settings and are even showing resistance to Metronidazole, once thought to be the gold standard bullet against anaerobes. Deep seated pressure ulcers are usually the site where anaerobe causes an infection in synergy with aerobes. AIMS AND OBJECTIVES Isolation of anaerobes in deep seated pressure ulcers using a novel innovative technique and to study their antibiogram profile. MATERIALS AND METHODS Swabs taken from depth of deep seated pressure ulcers were immediately inoculated in Brucella blood agar at bedside and placed in polycarbonate airtight jar for anaerobic incubation using a novel innovative Modified Candle Jar technique. In this technique five grams of grease-free grade zero steel wool were dipped in 50ml freshly prepared acidified copper sulphate solution until the copper colour appeared. Excess solution was drained and the steel wool was moulded into a loose pad to fit on an open Petri plate placed on top of the inoculated Brucella blood agar plates. A white-wax candle was placed at the centre of this plate. A small test tube containing mixture of 0.5g sodium-bicarbonate and 0.5g magnesium carbonate was kept ready to be placed inside the jar, just after placing the inoculated plate and incubated for 48 hours. RESULTS Peptostreptococcus anaerobius and Bacteroides fragilis were successfully isolated from deep seated pressure ulcers by this method. Antibiogram studies were done using the

  16. Effect of a Semi-Purified Oligosaccharide-Enriched Fraction from Caprine Milk on Barrier Integrity and Mucin Production of Co-Culture Models of the Small and Large Intestinal Epithelium

    Directory of Open Access Journals (Sweden)

    Alicia M. Barnett

    2016-05-01

    Full Text Available Caprine milk contains the highest amount of oligosaccharides among domestic animals, which are structurally similar to human milk oligosaccharides (HMOs. This suggests caprine milk oligosaccharides may offer similar protective and developmental effects to that of HMOs. However, to date, studies using oligosaccharides from caprine milk have been limited. Thus, this study aimed to examine the impact of a caprine milk oligosaccharide-enriched fraction (CMOF on barrier function of epithelial cell co-cultures of absorptive enterocytes (Caco-2 cells and mucus-secreting goblet cells (HT29-MTX cells, that more closely simulate the cell proportions found in the small (90:10 and large intestine (75:25. Treatment of epithelial co-cultures with 0.4, 1.0, 2.0 and 4.0 mg/mL of CMOF was shown to have no effect on metabolic activity but did enhance cell epithelial barrier integrity as measured by trans-epithelial electrical resistance (TEER, in a dose-dependent manner. The CMOF at the maximum concentration tested (4.0 mg/mL enhanced TEER, mucin gene expression and mucin protein abundance of epithelial co-cultures, all of which are essential components of intestinal barrier function.

  17. Metabolic capabilities of microorganisms involved in and associated with the anaerobic oxidation of methane

    Directory of Open Access Journals (Sweden)

    Gunter eWegener

    2016-02-01

    Full Text Available In marine sediments the anaerobic oxidation of methane with sulfate as electron acceptor (AOM is responsible for the removal of a major part of the greenhouse gas methane. AOM is performed by consortia of anaerobic methane-oxidizing archaea (ANME and their specific partner bacteria. The physiology of these organisms is poorly understood, which is due to their slow growth with doubling times in the order of months and the phylogenetic diversity in natural and in vitro AOM enrichments. Here we study sediment-free long-term AOM enrichments that were cultivated from seep sediments sampled off the Italian Island Elba (20°C; hereon called E20 and from hot vents of the Guaymas Basin, Gulf of California, cultivated at 37°C (G37 or at 50°C (G50. These enrichments were dominated by consortia of ANME-2 archaea and Seep-SRB2 partner bacteria (E20 or by ANME-1, forming consortia with Seep-SRB2 bacteria (G37 or with bacteria of the HotSeep-1 cluster (G50. We investigate lipid membrane compositions as possible factors for the different temperature affinities of the different ANME clades and show autotrophy as characteristic feature for both ANME clades and their partner bacteria. Although in the absence of additional substrates methane formation was not observed, methanogenesis from methylated substrates (methanol and methylamine could be quickly stimulated in the E20 and the G37 enrichment. Responsible for methanogenesis are archaea from the genus Methanohalophilus and Methanococcoides, which are minor community members during AOM (1 to 7‰ of archaeal 16S rRNA gene amplicons. In the same two cultures also sulfur disproportionation could be quickly stimulated by addition of zero-valent colloidal sulfur. The isolated partner bacteria are likewise minor community members (1 to 9‰ of bacterial 16S rRNA gene amplicons, whereas the dominant partner bacteria (Seep-SRB1a, Seep-SRB2 or HotSeep-1 did not grow on elemental sulfur. Our results support a

  18. Metabolic Capabilities of Microorganisms Involved in and Associated with the Anaerobic Oxidation of Methane.

    Science.gov (United States)

    Wegener, Gunter; Krukenberg, Viola; Ruff, S Emil; Kellermann, Matthias Y; Knittel, Katrin

    2016-01-01

    In marine sediments the anaerobic oxidation of methane with sulfate as electron acceptor (AOM) is responsible for the removal of a major part of the greenhouse gas methane. AOM is performed by consortia of anaerobic methane-oxidizing archaea (ANME) and their specific partner bacteria. The physiology of these organisms is poorly understood, which is due to their slow growth with doubling times in the order of months and the phylogenetic diversity in natural and in vitro AOM enrichments. Here we study sediment-free long-term AOM enrichments that were cultivated from seep sediments sampled off the Italian Island Elba (20°C; hereon called E20) and from hot vents of the Guaymas Basin, Gulf of California, cultivated at 37°C (G37) or at 50°C (G50). These enrichments were dominated by consortia of ANME-2 archaea and Seep-SRB2 partner bacteria (E20) or by ANME-1, forming consortia with Seep-SRB2 bacteria (G37) or with bacteria of the HotSeep-1 cluster (G50). We investigate lipid membrane compositions as possible factors for the different temperature affinities of the different ANME clades and show autotrophy as characteristic feature for both ANME clades and their partner bacteria. Although in the absence of additional substrates methane formation was not observed, methanogenesis from methylated substrates (methanol and methylamine) could be quickly stimulated in the E20 and the G37 enrichment. Responsible for methanogenesis are archaea from the genus Methanohalophilus and Methanococcoides, which are minor community members during AOM (1-7‰ of archaeal 16S rRNA gene amplicons). In the same two cultures also sulfur disproportionation could be quickly stimulated by addition of zero-valent colloidal sulfur. The isolated partner bacteria are likewise minor community members (1-9‰ of bacterial 16S rRNA gene amplicons), whereas the dominant partner bacteria (Seep-SRB1a, Seep-SRB2, or HotSeep-1) did not grow on elemental sulfur. Our results support a functioning of AOM as

  19. cultural

    Directory of Open Access Journals (Sweden)

    Irene Kreutz

    2006-01-01

    Full Text Available Es un estudio cualitativo que adoptó como referencial teorico-motodológico la antropología y la etnografía. Presenta las experiencias vivenciadas por mujeres de una comunidad en el proceso salud-enfermedad, con el objetivo de comprender los determinantes sócio-culturales e históricos de las prácticas de prevención y tratamiento adoptados por el grupo cultural por medio de la entrevista semi-estructurada. Los temas que emergieron fueron: la relación entre la alimentación y lo proceso salud-enfermedad, las relaciones con el sistema de salud oficial y el proceso salud-enfermedad y lo sobrenatural. Los dados revelaron que los moradores de la comunidad investigada tienen un modo particular de explicar sus procedimientos terapéuticos. Consideramos que es papel de los profesionales de la salud en sus prácticas, la adopción de abordajes o enfoques que consideren al individuo en su dimensión sócio-cultural e histórica, considerando la enorme diversidad cultural en nuestro país.

  20. Enhanced anaerobic biological treatment of phenolic wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Kindzierski, W.B.

    1989-01-01

    The combined treatment requirements for a high strength phenolic wastewater were examined in batch and semicontinuous anaerobic methanogenic bioassays. Solvent extraction pretreatment and in-situ addition of activated carbon during anaerobic treatment were effective in removing phenol from a coal liquefaction wastewater from the H-coal process. The selective pH adjustment of high strength phenolic wastewater followed by diisopropyl ether extraction reduced the phenolic concentration to non-inhibitory levels, and removed non-phenolic inhibitory compounds. The weakly acid nature of phenol and substituted phenols allows for their selective removal by solvent extraction. Anaerobic bacteria were able to degrade phenol in the solvent extracted wastwater, however, the bacteria exhibited instability under semicontinuous feeding conditions. The addition of activated carbon to the stressed phenol-degrading cultures improved their ability to remove phenol from solution. Further investigation into the role activated carbon performed during anaerobic phenol treatment demonstrated its importance as a biological support, in addition to providing adsorptive capacity for organic (including inhibitory) compounds. The similar study of other support materials (ion exchange resins) which did not possess an adsorptive capacity for organic compounds supported these findings. Excellent agreement was demonstrated among physical evaluation methods, performance bioassays, radiolabelled cell adsorption studies, and scanning electron microscopy observations in judging the value of the materials as biological supports.

  1. Methane dependent denitrification- from ecosystem to laboratory-scale enrichment for engineering applications.

    Science.gov (United States)

    Bhattacharjee, Ananda Shankar; Motlagh, Amir Mohaghegh; Jetten, Mike S M; Goel, Ramesh

    2016-08-01

    Managing nitrogen and carbon cycles in engineered and natural ecosystems is an environmental challenge. In this manuscript, we report a process which connects these two cycles with immense ecological and engineering significance. Sediments, collected from Jordan River in Salt Lake City, Utah were used as seed to start a laboratory-scale denitrification coupled to anaerobic methane oxidation (n-DAMO) reactor fed with methane (CH4) and nitrite (NO2(-)). Methane (CH4)-dependent denitrification in sediments of a nutrient-impaired river was found to be in the range of 40 nmol kg(-1) d(-1) to 70 nmol kg(-1) d(-1). Post 19 months of operation of the lab scale reactor, the n-DAMO reactor achieved nitrite removal rate of 2.88 mmol L(-1) d(-1). Enrichment of n-DAMO prokaryotes was evident from the increase in 16S rRNA gene copy number of bacteria belonging to the NC10 phylum in the reactor, corroborating with increase in the oxidation rates of CH4 coupled with NO2(-)-N removal from 21 μM to 190 μM of CH4 d(-1). Based on stable isotope experiments by other researchers, nitric oxide dismutase (nod) functional gene was hypothesized to be responsible for splitting nitric oxide to nitrogen and oxygen and this internally generated oxygen is utilized by n-DAMO prokaryotes to oxidize methane gas. Primers targeting the unique nitric oxide dismutase (nod) gene were developed and tested on the enrichment culture for the first time. This revealed that n-DAMO organisms are closely related yet distinct from, the M. oxyfera which had been enriched in earlier studies. The results emphasize tremendous future promise to use these novel organisms for wastewater treatment purposes, especially to take advantage of the dissolved methane present in anaerobic digester effluents. PMID:27176548

  2. Growth and Methane Oxidation Rates of Anaerobic Methanotrophic Archaea in a Continuous-Flow Bioreactor

    OpenAIRE

    Peter R. Girguis; Orphan, Victoria J; Hallam, Steven J.; DeLong, Edward F

    2003-01-01

    Anaerobic methanotrophic archaea have recently been identified in anoxic marine sediments, but have not yet been recovered in pure culture. Physiological studies on freshly collected samples containing archaea and their sulfate-reducing syntrophic partners have been conducted, but sample availability and viability can limit the scope of these experiments. To better study microbial anaerobic methane oxidation, we developed a novel continuous-flow anaerobic methane incubation system (AMIS) that...

  3. The anaerobic digestion process

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, C.J. [National Renewable Energy Lab., Golden, CO (United States); Boone, D.R. [Oregon Graduate Inst., Portland, OR (United States)

    1996-01-01

    The microbial process of converting organic matter into methane and carbon dioxide is so complex that anaerobic digesters have long been treated as {open_quotes}black boxes.{close_quotes} Research into this process during the past few decades has gradually unraveled this complexity, but many questions remain. The major biochemical reactions for forming methane by methanogens are largely understood, and evolutionary studies indicate that these microbes are as different from bacteria as they are from plants and animals. In anaerobic digesters, methanogens are at the terminus of a metabolic web, in which the reactions of myriads of other microbes produce a very limited range of compounds - mainly acetate, hydrogen, and formate - on which the methanogens grow and from which they form methane. {open_quotes}Interspecies hydrogen-transfer{close_quotes} and {open_quotes}interspecies formate-transfer{close_quotes} are major mechanisms by which methanogens obtain their substrates and by which volatile fatty acids are degraded. Present understanding of these reactions and other complex interactions among the bacteria involved in anaerobic digestion is only now to the point where anaerobic digesters need no longer be treated as black boxes.

  4. Anaerobic biological treatment

    International Nuclear Information System (INIS)

    The Enso-Fenox process has been very successfully used to remove chlorinated phenolic compounds from pulp bleaching effluents. It is a two-stage anaerobic/aerobic process consisting of a nonmethanogenic anaerobic fluidized bed followed by a trickling filter. Studies have been conducted on reductive dechlorination of chlorinated aromatic compounds under anaerobic conditions with chlorinated phenols as the sole carbon and energy source. Approximately 40% of the added chlorophenols was converted to CH4 and CO2. Substrate loading rates were 20 mg/L/d at hydraulic detention times of 2-4 days with 90% substrate conversion efficiency. Reductive dechlorination of mono, di-, tri-, and pentachlorophenols has been demonstrated in anaerobic sewage sludge. The following constituents were tested in the laboratory at their approximate concentrations in coal conversion wastewater (CCWW) and were anaerobically degraded in serum bottles: 1,000 mg/L phenol; 500 mg/L resorcinol; 1,000 mg/L benzoic acid; 500 mg/L p-cresol; 200 mg/L pyridine; 2,000 mg/L benzoic acid; 250 mg/L 40 methylcatechol; 500 mg/L 4-ethylpyridine; and 2,000 mg/L hexanoic acid. A petrochemical may initially exhibit toxicity to an unacclimated population of methane-fermenting bacteria, but with acclimation the toxicity may be greatly reduced or disappear. In addition, the microorganisms may develop the capacity to actually degrade compounds which showed initial toxicity. Since biomass digestion requires a complete consortium of bacteria, it is relevant to study the effect of a given process as well as to individual steps within the process. A toxicant can inhibit the rate-limiting step and/or change the step that is rate-limiting. Both manifestations of toxicity can severely affect the overall process

  5. HIGH-RATE ANAEROBIC TREATMENT OF ALCOHOLIC WASTEWATERS

    Directory of Open Access Journals (Sweden)

    Florencio L.

    1997-01-01

    Full Text Available Modern high-rate anaerobic wastewater treatment processes are rapidly becoming popular for industrial wastewater treatment. However, until recently stable process conditions could not be guaranteed for alcoholic wastewaters containing higher concentrations of methanol. Although methanol can be directly converted into methane by methanogens, under specific conditions it can also be converted into acetate and butyrate by acetogens. The accumulation of volatile fatty acids can lead to reactor instability in a weakly buffered reactor. Since this process was insufficiently understood, the application of high-rate anaerobic reactors was highly questionable. This research investigated the environmental factors that are of importance in the predominance of methylotrophic methanogens over acetogens in a natural mixed culture during anaerobic wastewater treatment in upflow anaerobic sludge bed reactors. Technological and microbiological aspects were investigated. Additionally, the route by which methanol is converted into methane is also presented

  6. Inhibition of the anaerobic digestion process by linear alkylbenzene sulfonates

    DEFF Research Database (Denmark)

    Gavala, Hariklia N.; Ahring, Birgitte Kiær

    2002-01-01

    it is important to investigate the effect of these xenobiotic compounds on an anaerobic environment. The inhibitory effect of Linear Alkylbenzene Sulfonates (LAS) on the acetogenic and methanogenic step of the anaerobic digestion process was studied. LAS inhibit both acetogenesis from propionate...... and methanogenesis from acetate and hydrogen and it is shown that the propionate-utilising bacteria are more sensitive to the presence of LAS than the acetoclastic methanogens. It has been proven that the inhibition intensity depends on the solids concentration and thus the term "biomass specific LAS concentration......" has been introduced in order to describe the phenomenon better. Conclusively, it is believed that the inhibitory effect of LAS is the main reason that anaerobic microbial enrichments on LAS have not been succeeded yet. Also, the inhibition caused by LAS on the acetogenic and methanogenic step...

  7. Fe(III) stimulates 3-methylindole and 4-methylphenol production in swine lagoon enrichments and Clostridium scatologenes ATCC 25775

    Science.gov (United States)

    Aims: To determine the effects of anaerobic electron acceptors on 3-methylindole (3-MI) and 4-methylphenol (4-MP) production in swine waste lagoon enrichments and Clostridium scatologenes ATCC 25775. Methods and Results: Swine waste lagoon sediment was incubated anaerobically in tryptone-yeast ext...

  8. Metabolic Capabilities of Microorganisms Involved in and Associated with the Anaerobic Oxidation of Methane

    OpenAIRE

    Wegener, Gunter; Krukenberg, Viola; Ruff, S. Emil; Kellermann, Matthias Y.; Knittel, Katrin

    2016-01-01

    In marine sediments the anaerobic oxidation of methane with sulfate as electron acceptor (AOM) is responsible for the removal of a major part of the greenhouse gas methane. AOM is performed by consortia of anaerobic methane-oxidizing archaea (ANME) and their specific partner bacteria. The physiology of these organisms is poorly understood, which is due to their slow growth with doubling times in the order of months and the phylogenetic diversity in natural and in vitro AOM enrichments. Here w...

  9. Beyond Job Enrichment to Employment Enrichment

    Science.gov (United States)

    Werther, William B., Jr.

    1975-01-01

    Employment enrichment views the total work environment confronting employees as a system consisting of two overlapping areas: worker-job and worker-organization subsystems. Job enrichment has improved the worker-job subsystem. The focus of this article is on methods of improving the worker-organization relationship. (Author/JB)

  10. Anaerobic azo dye reduction

    OpenAIRE

    Zee, van der, KG Kristoffer

    2002-01-01

    Azo dyes, aromatic moieties linked together by azo (-N=N-) chromophores, represent the largest class of dyes used in textile-processing and other industries. The release of these compounds into the environment is undesirable, not only because of their colour, but also because many azo dyes and their breakdown products are toxic and/or mutagenic to life. To remove azo dyes from wastewater, a biological treatment strategy based on anaerobic reduction of the azo dyes, followed by aerobic transfo...

  11. Community structure evolution and enrichment of glycogen-accumulating organisms producing polyhydroxyalkanoates from fermented molasses.

    Science.gov (United States)

    Pisco, Ana R; Bengtsson, Simon; Werker, Alan; Reis, Maria A M; Lemos, Paulo C

    2009-07-01

    An open mixed culture was enriched with glycogen-accumulating organisms (GAOs) by using a sequencing batch reactor and treating an agroindustrial waste (sugar cane molasses) under cyclic anaerobic-aerobic conditions. Over a 1-year operating period, the culture exhibited a very stable GAO phenotype with an average polyhydroxyalkanoate (PHA) content of 17% total suspended solids. However, the GAO microbial community evolved over the course of operation to a culture exhibiting unusual characteristics in producing PHAs comprised of short-chain-length monomers, namely, 3-hydroxybutyrate, 3-hydroxy-2-methylbutyrate, 3-hydroxyvalerate, and 3-hydroxy-2-methylvalerate, and also, up to 31 mol% of the medium-chain-length (MCL) monomer 3-hydroxyhexanoate (3HHx). Microbial community analysis by fluorescence in situ hybridization revealed a concurrent long-term drift in the GAO community balance, from mainly "Candidatus Competibacter phosphatis" to mainly Defluviicoccus vanus-related organisms. The production of 3HHx was confirmed by (13)C nuclear magnetic resonance (NMR) and appeared to be related to the increased presence of D. vanus-related GAOs. These results suggest a broadened spectrum of material, chemical, and mechanical properties that can be achieved for biopolymers produced by open mixed cultures from fermented waste. The increased spectrum of polymer properties brings a wider scope of potential applications. PMID:19465533

  12. Development of a rapid lateral flow immunoassay test for detection of exosomes previously enriched from cell culture medium and body fluids.

    Science.gov (United States)

    Oliveira-Rodríguez, Myriam; López-Cobo, Sheila; Reyburn, Hugh T; Costa-García, Agustín; López-Martín, Soraya; Yáñez-Mó, María; Cernuda-Morollón, Eva; Paschen, Annette; Valés-Gómez, Mar; Blanco-López, Maria Carmen

    2016-01-01

    Exosomes are cell-secreted nanovesicles (40-200 nm) that represent a rich source of novel biomarkers in the diagnosis and prognosis of certain diseases. Despite the increasingly recognized relevance of these vesicles as biomarkers, their detection has been limited due in part to current technical challenges in the rapid isolation and analysis of exosomes. The complexity of the development of analytical platforms relies on the heterogeneous composition of the exosome membrane. One of the most attractive tests is the inmunochromatographic strips, which allow rapid detection by unskilled operators. We have successfully developed a novel lateral flow immunoassay (LFIA) for the detection of exosomes based on the use of tetraspanins as targets. We have applied this platform for the detection of exosomes purified from different sources: cell culture supernatants, human plasma and urine. As proof of concept, we explored the analytical potential of this LFIA platform to accurately quantify exosomes purified from a human metastatic melanoma cell line. The one-step assay can be completed in 15 min, with a limit of detection of 8.54×10(5) exosomes/µL when a blend of anti-CD9 and anti-CD81 were selected as capture antibodies and anti-CD63 labelled with gold nanoparticles as detection antibody. Based on our results, this platform could be well suited to be used as a rapid exosome quantification tool, with promising diagnostic applications, bearing in mind that the detection of exosomes from different sources may require adaptation of the analytical settings to their specific composition. PMID:27527605

  13. Development of a rapid lateral flow immunoassay test for detection of exosomes previously enriched from cell culture medium and body fluids

    Directory of Open Access Journals (Sweden)

    Myriam Oliveira-Rodríguez

    2016-08-01

    Full Text Available Exosomes are cell-secreted nanovesicles (40–200 nm that represent a rich source of novel biomarkers in the diagnosis and prognosis of certain diseases. Despite the increasingly recognized relevance of these vesicles as biomarkers, their detection has been limited due in part to current technical challenges in the rapid isolation and analysis of exosomes. The complexity of the development of analytical platforms relies on the heterogeneous composition of the exosome membrane. One of the most attractive tests is the inmunochromatographic strips, which allow rapid detection by unskilled operators. We have successfully developed a novel lateral flow immunoassay (LFIA for the detection of exosomes based on the use of tetraspanins as targets. We have applied this platform for the detection of exosomes purified from different sources: cell culture supernatants, human plasma and urine. As proof of concept, we explored the analytical potential of this LFIA platform to accurately quantify exosomes purified from a human metastatic melanoma cell line. The one-step assay can be completed in 15 min, with a limit of detection of 8.54×105 exosomes/µL when a blend of anti-CD9 and anti-CD81 were selected as capture antibodies and anti-CD63 labelled with gold nanoparticles as detection antibody. Based on our results, this platform could be well suited to be used as a rapid exosome quantification tool, with promising diagnostic applications, bearing in mind that the detection of exosomes from different sources may require adaptation of the analytical settings to their specific composition.

  14. Enrichment of Breast Cancer Stem Cells by Serum-free Shaking Suspension Culture%无血清摇动悬浮培养富集乳腺癌干细胞

    Institute of Scientific and Technical Information of China (English)

    闫文星; 陈玉丙; 张红梅; 国春龙; 王铁君

    2011-01-01

    Objective To investigate the characteristics of division of breast cancer MCF-7 cells under various conditions so as to develop a rapid and effective method for enrichment of breast cancer stem cells. Methods MCF-7 cells were subjected to static culture in complete medium (group A), shaking culture in complete medium (group B), static culture with cytokine (group C) and shaking culture with cytokine (group D) respectively, for 12, 24 and 36 h, then observed for division under inverted phase contrast microscope, based on which clone formation rate was calculated, and determined for the percentage of CD44+/CD24"/low lymphocyte subsets. Results In groups B and C, rod-like divisions were observed in both about 30% of cells 12 h, and in about 50% and about 60% of cells respectively 24 h, while large cell clones were formed 36 h after culture. However, in group D, rod-like division was observed in about 50% of cells 12 h, and in about 80% of cells 24 h when several cell clones appeared, while the number of cell clones decreased 36 h after culture. The percentage of CD44+/CD24"/km lymphocyte subsets 12 h after culture in group D (8. 05%) was 8 times of those in group B (0. 99%) and 2. 1 times of those in group C (3. 80%). However, the percentage 24 h after culture in group D (15. 24%) was 3 times of those in group B (4. 83%) and 6 times of those in group C (2. 30%). The percentage in group D decreased to 9. 68% 36 h after culture, which was about 9 times of those in groups B (0. 95%) and C (1. 03%). Conclusion The mitotic division of MCF-7 cells was accelerated in shaking culture with cytokine, while the percentage of CD44+/CD24'/low lymphocyte subsets increased rapidly, and stem cell pool increased significantly, indicating serum-free shaking suspension culture a rapid and effective method for enrichment of breast cancer stem cells.%目的 探讨不同培养条件下乳腺癌MCF-7细胞的分裂特点,建立快速、有效的乳腺癌干细胞富集方法.方法 将MCF-7

  15. Potential Application of Anaerobic Extremophiles for Hydrogen Production

    Science.gov (United States)

    Pikuta, Elena V.; Hoover, Richard B.

    2004-01-01

    During substrate fermentation many anaerobes produce the hydrogen as a waste product, which often regulates the growth of the cultures as an inhibitor. In nature the hydrogen is usually removed from the ecosystem due to its physical properties or by consumption of hydrogen by secondary anaerobes, which sometimes behave as competitors for electron donors as is seen in the classical example in anaerobic microbial communities via the interaction between methanogens and sulfate- or sulfur- reducers. It was demonstrated previously on mixed cultures of anaerobes at neutral pH that bacterial hydrogen production could provide an alternative energy source. But at neutral pH the original cultures can easily be contaminated by methanogens, a most unpleasant side effect of these conditions is the development of pathogenic bacteria. In both cases the rate of hydrogen production was dramatically decreased since some part of the hydrogen was transformed to methane, and the cultivation of human pathogens on a global scale is very dangerous. In our laboratory, experiments with obligately alkaliphilic bacteria that excrete hydrogen as the end metabolic product were performed at different temperature regimes. Mesophilic and moderately thermophilic bacterial cultures have been studied and compared for the most effective hydrogen production. For high-mineralized media with pH 9.5-10.0 not many methanogens are known to exist. Furthermore, the development of pathogenic contaminant microorganisms is virtually impossible: carbonate-saturated solutions are used as antiseptics in medicine. Therefore the cultivation of alkaliphilic hydrogen producing bacteria could be considered as most safe process for global Scale industry in future. Here we present experimental data on the rates of hydrogen productivity for mesophilic, alkaliphilic, obligately anaerobic bacterium Spirocheta americana ASpG1 and moderately thermophilic, alkaliphilic, facultative anaerobe Anoxybacillus pushchinoensis K1 and

  16. New perspectives in anaerobic digestion

    DEFF Research Database (Denmark)

    van Lier, J.B.; Tilche, A.; Ahring, Birgitte Kiær;

    2001-01-01

    requirements. In fact, most advances were achieved during the last three decades, when high-rate reactor systems were developed and a profound insight was obtained in the microbiology of the anaerobic communities. This insight led to a better understanding of anaerobic treatment and, subsequently, to a broader......The IWA specialised group on anaerobic digestion (AD) is one of the oldest working groups of the former IAWQ organisation. Despite the fact that anaerobic technology dates back more than 100 years, the technology is still under development, adapting novel treatment systems to the modern...

  17. Some unique features of alkaliphilic anaerobes

    Science.gov (United States)

    Roof, Erin; Pikuta, Elena; Otto, Christopher; Williams, George; Hoover, Richard

    2013-09-01

    This article explores two topics involving the examination of four strains of alkaliphilic anaerobes. The first topic was dedicated to detection of the ability of microorganisms to metabolize alternative chirality substrates. Two saccharolytic anaerobic bacteria were chosen for the first experiment: Anaerovirgula multivorans strain SCAT, which is gram positive and spore-forming; and Spirochaeta dissipatitropha, strain ASpC2T, which is gram negative. It was found that both checked sugarlytics were able to use L-ribose and L-arabinose, as growth substrates. The second part was concerned of study a chemolithotrophy in two halo-alkaliphilic sulfate reducing bacteria: Desulfonatornum thiodismutans strain MLF1T and Desulfonatronum lacustre strain Z-7951T. The experiments with lithotrophs had demonstrated that strain MLF1T was capable to grow without any organic source of carbon, while strain Z-7951T had required at least 2 mM sodium acetate for growth. Anaerobic technique was used for preparation of the growth media and maintenance of these bacterial cultures. Standard methods for Gram, spore, and flagella staining were applied for characterization of cytomorphology. In this article, the results of the experiments performed on cytological, physiological, and biochemical levels are presented and discussed.

  18. Cultivation and irradiation of human fibroblasts in a medium enriched with platelet lysate for obtaining feeder layer in epidermal cell culture; Cultivo e irradiacao de fibroblastos humanos em meio enriquecido com lisado de plaquetas para obtencao de camada de sustentacao em culturas de celulas da epiderme

    Energy Technology Data Exchange (ETDEWEB)

    Yoshito, Daniele

    2011-07-01

    For over 30 years, the use of culture medium, enriched with bovine serum, and murines fibroblasts, with the rate of proliferation controlled by irradiation or by share anticarcinogenic drugs, has been playing successfully its role in assisting in the development of keratinocytes in culture, for clinical purposes. However, currently there is a growing concern about the possibility of transmitting prions and animals viruses to transplanted patients. Taking into account this concern, the present work aims to cultivate human fibroblasts in a medium enriched with human platelets lysate and determine the irradiation dose of these cells, for obtaining feeder layer in epidermal cell culture. For carrying out the proposed objective, platelets lysis has standardized, this lysate was used for human fibroblasts cultivation and the irradiation dose enough to inhibit its duplication was evaluated. Human keratinocytes were cultivated in these feeder layers, in culture medium enriched with the lysate. With these results we conclude that the 10% platelets lysate promoted a better adhesion and proliferation of human fibroblasts and in all dose levels tested (60 to 300 Gy), these had their mitotic activity inactivated by ionizing irradiation, being that the feeder layers obtained with doses from 70 to 150 Gy were those that provided the best development of keratinocytes in medium containing 2.5% of human platelet lysate. Therefore, it was possible to standardize both the cultivation of human fibroblasts as its inactivation for use as feeder layer in culture of keratinocytes, so as to eliminate xenobiotics components. (author)

  19. Anaerobic wastewater treatment using anaerobic baffled bioreactor: a review

    Science.gov (United States)

    Hassan, Siti; Dahlan, Irvan

    2013-09-01

    Anaerobic wastewater treatment is receiving renewed interest because it offers a means to treat wastewater with lower energy investment. Because the microorganisms involved grow more slowly, such systems require clever design so that the microbes have sufficient time with the substrate to complete treatment without requiring enormous reactor volumes. The anaerobic baffled reactor has inherent advantages over single compartment reactors due to its circulation pattern that approaches a plug flow reactor. The physical configuration of the anaerobic baffled reactor enables significant modifications to be made; resulting in a reactor which is proficient of treating complex wastewaters which presently require only one unit, ultimately significant reducing capital costs. This paper also concerns about mechanism, kinetic and hydrodynamic studies of anaerobic digestion for future application of the anaerobic baffled reactor for wastewater treatment.

  20. Microbial degradation of 4-monobrominated diphenyl ether with anaerobic sludge

    Energy Technology Data Exchange (ETDEWEB)

    Shih, Yang-hsin, E-mail: yhs@ntu.edu.tw [Department of Agricultural Chemistry, National Taiwan University, Taipei 106, Taiwan, ROC (China); Chou, Hsi-Ling [Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung 407, Taiwan, ROC (China); Peng, Yu-Huei [Department of Agricultural Chemistry, National Taiwan University, Taipei 106, Taiwan, ROC (China)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer BDE-3 was degraded with two anaerobes in different rates. Black-Right-Pointing-Pointer Glucose addition augment the debromination efficiencies. Black-Right-Pointing-Pointer Hydrogen gas was detected and relative microbes were identified. Black-Right-Pointing-Pointer Extra-carbon source enhanced degradation partial due to H{sub 2}-generation bacteria. - Abstract: Polybrominated diphenyl ethers (PBDEs) are widely used flame retardant additives for many plastic and electronic products. Owing to their ubiquitous distribution in the environment, multiple toxicity to humans, and increasing accumulation in the environment, the fate of PBDEs is of serious concern for public safety. In this study, the degradation of 4-monobrominated diphenyl ether (BDE-3) in anaerobic sludge and the effect of carbon source addition were investigated. BDE-3 can be degraded by two different anaerobic sludge samples. The by-products, diphenyl ether (DE) and bromide ions, were monitored, indicating the reaction of debromination within these anaerobic samples. Co-metabolism with glucose facilitated BDE-3 biodegradation in terms of kinetics and efficiency in the Jhongsing sludge. Through the pattern of amplified 16S rRNA gene fragments in denatured gradient gel electrophoresis (DGGE), the composition of the microbial community was analyzed. Most of the predominant microbes were novel species. The fragments enriched in BDE-3-degrading anaerobic sludge samples are presumably Clostridium sp. This enrichment coincides with the H{sub 2} gas generation and the facilitation of debromination during the degradation process. Findings of this study provide better understanding of the biodegradation of brominated DEs and can facilitate the prediction of the fate of PBDEs in the environment.

  1. Economic viability of anaerobic digestion

    Energy Technology Data Exchange (ETDEWEB)

    Wellinger, A. [INFOENERGIE, Ettenhausen (Switzerland)

    1996-01-01

    The industrial application of anaerobic digestion is a relatively new, yet proven waste treatment technology. Anaerobic digestion reduces and upgrades organic waste, and is a good way to control air pollution as it reduces methane and nitrous gas emissions. For environmental and energy considerations, anaerobic digestion is a nearly perfect waste treatment process. However, its economic viability is still in question. A number of parameters - type of waste (solid or liquid), digester system, facility size, product quality and end use, environmental requirements, cost of alternative treatments (including labor), and interest rates - define the investment and operating costs of an anaerobic digestion facility. Therefore, identical facilities that treat the same amount and type of waste may, depending on location, legislation, and end product characteristics, reveal radically different costs. A good approach for evaluating the economics of anaerobic digestion is to compare it to treatment techniques such as aeration or conventional sewage treatment (for industrial wastewater), or composting and incineration (for solid organic waste). For example, the cost (per ton of waste) of in-vessel composting with biofilters is somewhat higher than that of anaerobic digestion, but the investment costs 1 1/2 to 2 times more than either composting or anaerobic digestion. Two distinct advantages of anaerobic digestion are: (1) it requires less land than either composting or incinerating, which translates into lower costs and milder environmental and community impacts (especially in densely populated areas); and (2) it produces net energy, which can be used to operate the facility or sold to nearby industries.

  2. Anaerobic Digestion of Piggery Waste

    NARCIS (Netherlands)

    Velsen, van A.F.M.

    1981-01-01

    Anaerobic digestion is a biological process by which organic matter is converted to methane and carbon dioxide by microbes in the absence of air (oxygen). In nature, anaerobic conversions occur at all places where organic material accumulates and the supply of oxygen is deficient, e.g. in marshes an

  3. In vitro Characterization of Phenylacetate Decarboxylase, a Novel Enzyme Catalyzing Toluene Biosynthesis in an Anaerobic Microbial Community.

    Science.gov (United States)

    Zargar, K; Saville, R; Phelan, R M; Tringe, S G; Petzold, C J; Keasling, J D; Beller, H R

    2016-08-10

    Anaerobic bacterial biosynthesis of toluene from phenylacetate was reported more than two decades ago, but the biochemistry underlying this novel metabolism has never been elucidated. Here we report results of in vitro characterization studies of a novel phenylacetate decarboxylase from an anaerobic, sewage-derived enrichment culture that quantitatively produces toluene from phenylacetate; complementary metagenomic and metaproteomic analyses are also presented. Among the noteworthy findings is that this enzyme is not the well-characterized clostridial p-hydroxyphenylacetate decarboxylase (CsdBC). However, the toluene synthase under study appears to be able to catalyze both phenylacetate and p-hydroxyphenylacetate decarboxylation. Observations suggesting that phenylacetate and p-hydroxyphenylacetate decarboxylation in complex cell-free extracts were catalyzed by the same enzyme include the following: (i) the specific activity for both substrates was comparable in cell-free extracts, (ii) the two activities displayed identical behavior during chromatographic separation of cell-free extracts, (iii) both activities were irreversibly inactivated upon exposure to O2, and (iv) both activities were similarly inhibited by an amide analog of p-hydroxyphenylacetate. Based upon these and other data, we hypothesize that the toluene synthase reaction involves a glycyl radical decarboxylase. This first-time study of the phenylacetate decarboxylase reaction constitutes an important step in understanding and ultimately harnessing it for making bio-based toluene.

  4. Bio-oil upgrading strategies to improve PHA production from selected aerobic mixed cultures.

    Science.gov (United States)

    Moita Fidalgo, Rita; Ortigueira, Joana; Freches, André; Pelica, João; Gonçalves, Magarida; Mendes, Benilde; Lemos, Paulo C

    2014-06-25

    Recent research on polyhydroxyalkanoates (PHAs) has focused on developing cost-effective production processes using low-value or industrial waste/surplus as substrate. One of such substrates is the liquid fraction resulting from pyrolysis processes, bio-oil. In this study, valorisation of bio-oil through PHA production was investigated. The impact of the complex bio-oil matrix on PHA production by an enriched mixed culture was examined. The performance of the direct utilization of pure bio-oil was compared with the utilization of three defined substrates contained in this bio-oil: acetate, glucose and xylose. When compared with acetate, bio-oil revealed lower capacity for polymer production as a result of a lower polymer yield on substrate and a lower PHA cell content. Two strategies for bio-oil upgrade were performed, anaerobic fermentation and vacuum distillation, and the resulting liquid streams were tested for polymer production. The first one was enriched in volatile fatty acids and the second one mainly on phenolic and long-chain fatty acids. PHA accumulation assays using the upgraded bio-oils attained polymer yields on substrate similar or higher than the one achieved with acetate, although with a lower PHA content. The capacity to use the enriched fractions for polymer production has yet to be optimized. The anaerobic digestion of bio-oil could also open-up the possibility to use the fermented bio-oil directly in the enrichment process of the mixed culture. This would increase the selective pressure toward an optimized PHA accumulating culture selection.

  5. Impact of salinity on the anaerobic metabolism of phosphate-accumulating organisms (PAO) and glycogen-accumulating organisms (GAO).

    Science.gov (United States)

    Welles, L; Lopez-Vazquez, C M; Hooijmans, C M; van Loosdrecht, M C M; Brdjanovic, D

    2014-09-01

    The use of saline water as secondary quality water in urban environments for sanitation is a promising alternative towards mitigating fresh water scarcity. However, this alternative will increase the salinity in the wastewater generated that may affect the biological wastewater treatment processes, such as biological phosphorus removal. In addition to the production of saline wastewater by the direct use of saline water in urban environments, saline wastewater is also generated by some industries. Intrusion of saline water into the sewers is another source of salinity entering the wastewater treatment plant. In this study, the short-term effects of salinity on the anaerobic metabolism of phosphate-accumulating organisms (PAO) and glycogen-accumulating organisms (GAO) were investigated to assess the impact of salinity on enhanced biological phosphorus removal. Hereto, PAO and GAO cultures enriched at a relatively low salinity level (0.02 % W/V) were exposed to salinity concentrations of up to 6 % (as NaCl) in anaerobic batch tests. It was demonstrated that both PAO and GAO are affected by higher salinity levels, with PAO being the more sensitive organisms to the increasing salinity. The maximum acetate uptake rate of PAO decreased by 71 % when the salinity increased from 0 to 1 %, while that of GAO decreased by 41 % for the same salinity increase. Regarding the stoichiometry of PAO, a decrease in the P-release/HAc uptake ratio accompanied with an increase in the glycogen consumption/HAc uptake ratio was observed for PAO when the salinity increased from 0 to 2 % salinity, indicating a metabolic shift from a poly-P-dependent to a glycogen-dependent metabolism. The anaerobic maintenance requirements of PAO and GAO increased as the salinity concentrations risen up to 4 % salinity. PMID:24831025

  6. Dynamic characteristics of Paracoccus denitrificans in alternate aerobic-anaerobic continuous cultivations

    Energy Technology Data Exchange (ETDEWEB)

    Waki, T.; Kawato, Y.; Shimatani, Y.; Ichikawa, K.

    1980-06-01

    The alternate aerobic-anaerobic continuous culture system was used to analyze the adaptation phenomena of Paracoccus denitrificans quantitatively, which will be observed in a single sludge nitrification-denitrification system. After the initial rapid reduction of nitrate in the anaerobic period, a rather high rate of nitrate reduction was maintained. The lag of adaptation to each condition was short and this was explained by the presence of large amounts of the cytochromes and enzymes required for both aerobic and nitrate/nitrite respirations. When the alternation cycle of aerobic and anaerobic conditions was short, the nitrate concentration was lower than that in anaerobic continuous cultures at the same dilution rate. The apparent specific rate of nitrate reduction was almost the same as that in anaerobic continuous cultures when the alternation cycle was short. On the other hand, the nitrite accumulated at high concentrations and the apparent specific rate of nitrite reduction was very low. The actual reduction rate of nitrate in the anaerobic periods was found to be unaffected by the length of the aerobic periods, however, the actual reduction rate of nitrite was highly affected by the aerobic periods. By considering the initial rapid reduction of nitrate in the alternate aerobic-anaerobic system, it was suggested that the higher recycling ratio which corresponds to the shorter alternation cycle, was effective in increasing the efficiency of nitrogen removal in the single sludge nitrification-denitrification system.

  7. Anaerobic bacteria colonizing the lower airways in lung cancer patients

    Directory of Open Access Journals (Sweden)

    Anna Malm

    2011-07-01

    Full Text Available Anaerobes comprise most of the endogenous oropharyngeal microflora, and can cause infections of airways in lung cancer patients who are at high risk for respiratory tract infections. The aim of this study was to determine the frequency and species diversity of anaerobes in specimens from the lower airways of lung cancer patients. Sensitivity of the isolates to conventional antimicrobial agents used in anaerobe therapy was assessed. Respiratory secretions obtained by bronchoscopy from 30 lung cancer patients were cultured onto Wilkins- -Chalgren agar in anaerobic conditions at 37°C for 72–96 hours. The isolates were identified using microtest Api 20A. The minimal inhibitory concentrations for penicillin G, amoxicillin/clavulanate, piperacillin/tazobactam, cefoxitin, imipenem, clindamycin, and metronidazole were determined by E-test. A total of 47 isolates of anaerobic bacteria were detected in 22 (73.3% specimens. More than one species of anaerobe was found in 16 (53.3% samples. The most frequently isolated were Actinomyces spp. and Peptostreptococcus spp., followed by Eubacterium lentum, Veillonella parvula, Prevotella spp., Bacteroides spp., Lactobacillus jensenii. Among antibiotics used in the study amoxicillin/clavulanate and imipenem were the most active in vitro (0% and 2% resistant strains, respectively. The highest resistance rate was found for penicillin G and metronidazole (36% and 38% resistant strains, respectively. The results obtained confirm the need to conduct analyses of anaerobic microflora colonizing the lower respiratory tract in patients with lung cancer to monitor potential etiologic factors of airways infections, as well as to propose efficient, empirical therapy. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 2, pp. 263–266

  8. Uranium enrichment. Principles

    International Nuclear Information System (INIS)

    Uranium enrichment industry is a more than 60 years old history and has developed without practically no cost, efficiency or profit constraints. However, remarkable improvements have been accomplished since the Second World War and have led to the development of various competing processes which reflect the diversity of uranium compositions and of uranium needs. Content: 1 - general considerations: uranium isotopes, problem of uranium enrichment, first realizations (USA, Russia, Europe, Asia, other countries), present day situation, future needs and market evolution; 2 - principles of isotopic separation: processes classification (high or low enrichment), low elementary enrichment processes, equilibrium time, cascade star-up and monitoring, multi-isotopes case, uranium reprocessing; 3 - enrichment and proliferation. (J.S.)

  9. Decrease in anaerobe-related bacteraemias and increase in Bacteroides species isolation rate from 1998 to 2007: a retrospective study.

    Science.gov (United States)

    Lazarovitch, Tsilia; Freimann, Sarit; Shapira, Galina; Blank, Helena

    2010-06-01

    Conflicting data have accumulated in recent years regarding the incidence of anaerobic bacteraemias. The aim of this study was to determine the prevalence of bacteraemias due to anaerobic bacteria and evaluate the importance of anaerobic blood cultures in a university hospital in Israel. A retrospective survey which focused on anaerobic blood culture bottles was performed on blood cultures received in our laboratory during the decade from January 1998 to December 2007. Anaerobic-related bacteraemias decreased during that period, whereas a significant increase was observed in Bacteroides species isolated from the blood cultures (from 18% during 1998-2002 to 43% during 2003-2007). Comparison of the medical records of 54 patients with Bacteroides-related bacteraemia during the two end periods (1998-1999 and 2006-2007) revealed a marked increase in complex underlying diseases. Hypertension and diabetes mellitus type II were found in 29% of the patients in 1998-1999 and increased to 43-45% of the patients in 2006-2007. Ischemic heart disease also increased from 14% of the patients in 1998-1999 to 43% in 2006-2007. We conclude that although positive anaerobic blood cultures account for a small percentage of positive blood samples, the growing involvement of Bacteroides species-related bacteraemias together with an increase in complex underlying diseases in these patients emphasize the importance of anaerobic blood cultures, particularly in patients with co-morbidities.

  10. Production of Volatile Derivatives of Metal(loid)s by Microflora Involved in Anaerobic Digestion of Sewage Sludge

    OpenAIRE

    Michalke, K.; Wickenheiser, E. B.; Mehring, M.; A. V. Hirner; Hensel, R.

    2000-01-01

    Gases released from anaerobic wastewater treatment facilities contain considerable amounts of volatile methyl and hydride derivatives of metals and metalloids, such as arsine (AsH3), monomethylarsine, dimethylarsine, trimethylarsine, trimethylbismuth (TMBi), elemental mercury (Hg0), trimethylstibine, dimethyltellurium, and tetramethyltin. Most of these compounds could be shown to be produced by pure cultures of microorganisms which are representatives of the anaerobic sewage sludge microflora...

  11. Anaerobic oxidation of methane associated with sulfate reduction in a natural freshwater gas source.

    Science.gov (United States)

    Timmers, Peer Ha; Suarez-Zuluaga, Diego A; van Rossem, Minke; Diender, Martijn; Stams, Alfons Jm; Plugge, Caroline M

    2016-06-01

    The occurrence of anaerobic oxidation of methane (AOM) and trace methane oxidation (TMO) was investigated in a freshwater natural gas source. Sediment samples were taken and analyzed for potential electron acceptors coupled to AOM. Long-term incubations with (13)C-labeled CH4 ((13)CH4) and different electron acceptors showed that both AOM and TMO occurred. In most conditions, (13)C-labeled CO2 ((13)CO2) simultaneously increased with methane formation, which is typical for TMO. In the presence of nitrate, neither methane formation nor methane oxidation occurred. Net AOM was measured only with sulfate as electron acceptor. Here, sulfide production occurred simultaneously with (13)CO2 production and no methanogenesis occurred, excluding TMO as a possible source for (13)CO2 production from (13)CH4. Archaeal 16S rRNA gene analysis showed the highest presence of ANME-2a/b (ANaerobic MEthane oxidizing archaea) and AAA (AOM Associated Archaea) sequences in the incubations with methane and sulfate as compared with only methane addition. Higher abundance of ANME-2a/b in incubations with methane and sulfate as compared with only sulfate addition was shown by qPCR analysis. Bacterial 16S rRNA gene analysis showed the presence of sulfate-reducing bacteria belonging to SEEP-SRB1. This is the first report that explicitly shows that AOM is associated with sulfate reduction in an enrichment culture of ANME-2a/b and AAA methanotrophs and SEEP-SRB1 sulfate reducers from a low-saline environment. PMID:26636551

  12. Anaerobic oxidation of methane associated with sulfate reduction in a natural freshwater gas source

    Science.gov (United States)

    Timmers, Peer HA; Suarez-Zuluaga, Diego A; van Rossem, Minke; Diender, Martijn; Stams, Alfons JM; Plugge, Caroline M

    2016-01-01

    The occurrence of anaerobic oxidation of methane (AOM) and trace methane oxidation (TMO) was investigated in a freshwater natural gas source. Sediment samples were taken and analyzed for potential electron acceptors coupled to AOM. Long-term incubations with 13C-labeled CH4 (13CH4) and different electron acceptors showed that both AOM and TMO occurred. In most conditions, 13C-labeled CO2 (13CO2) simultaneously increased with methane formation, which is typical for TMO. In the presence of nitrate, neither methane formation nor methane oxidation occurred. Net AOM was measured only with sulfate as electron acceptor. Here, sulfide production occurred simultaneously with 13CO2 production and no methanogenesis occurred, excluding TMO as a possible source for 13CO2 production from 13CH4. Archaeal 16S rRNA gene analysis showed the highest presence of ANME-2a/b (ANaerobic MEthane oxidizing archaea) and AAA (AOM Associated Archaea) sequences in the incubations with methane and sulfate as compared with only methane addition. Higher abundance of ANME-2a/b in incubations with methane and sulfate as compared with only sulfate addition was shown by qPCR analysis. Bacterial 16S rRNA gene analysis showed the presence of sulfate-reducing bacteria belonging to SEEP-SRB1. This is the first report that explicitly shows that AOM is associated with sulfate reduction in an enrichment culture of ANME-2a/b and AAA methanotrophs and SEEP-SRB1 sulfate reducers from a low-saline environment. PMID:26636551

  13. [Research advances on anaerobic ferrous-oxidizing microorganisms].

    Science.gov (United States)

    Zhang, Meng; Zheng, Ping; Ji, Jun-yuan

    2013-08-01

    Anaerobic ferrous-oxidizing microorganisms (AFOM) are one of the important discoveries in microbiology, geology and environmental science. The study of AFOM is of significance to make clear the banded iron formations (BIFs), promote the biogeochemical cycles of iron, nitrogen and carbon, enrich the microbiological content, develop new biotechnologies for anaerobic iron oxidation, and explore the ancient earth environment and extraterrestrial life. This paper summarized the research advances on AFOM, introduced the habitats of AFOM, discussed the biodiversity and the nutritive and metabolic characteristics of AFOM, and assessed the potential functions of AFOM. An outlook was made on the future researches of new species AFOM, their microbial metabolism mechanisms, and their development and applications. PMID:24380362

  14. Potential application of anaerobic extremophiles for hydrogen production

    Science.gov (United States)

    Pikuta, Elena V.; Hoover, Richard B.

    2004-11-01

    In processes of the substrate fermentation most anaerobes produce molecular hydrogen as a waste end product, which often controls the culture growth as an inhibitor. Usually in nature the hydrogen is easily removed from an ecosystem, due to its physical features, and an immediate consumption by the secondary anaerobes that sometimes behave as competitors for electron donors; a classical example of this kind of substrate competition in anaerobic microbial communities is the interaction between methanogens and sulfate- or sulfur-reducers. Previously, on the mixed cultures of anaerobes at neutral pH, it was demonstrated that bacterial hydrogen production could provide a good alternative energy source. At neutral pH the original cultures could easily contaminated by methanogens, and the most unpleasant side effect of these conditions is the development of pathogenic bacteria. In both cases the rate of hydrogen production was dramatically decreased since some part of the hydrogen was transformed to methane, and furthermore, the cultivation with pathogenic contaminants on an industrial scale would create an unsafe situation. In our laboratory the experiments with obligately alkaliphilic bacteria producing hydrogen as an end metabolic product were performed at different conditions. The mesophilic, haloalkaliphilic and obligately anaerobic bacterium Spirochaeta americana ASpG1T was studied and various cultivation regimes were compared for the most effective hydrogen production. In a highly mineralized media with pH 9.5-10.0 not many known methanogens are capable of growth, and the probability of developing pathogenic contaminants is theoretically is close to zero (in medicine carbonate- saturated solutions are applied as antiseptics). Therefore the cultivation of alkaliphilic hydrogen producing bacteria could be considered as a safe and economical process for large-scale industrial bio-hydrogen production in the future. Here we present and discuss the experimental data

  15. Relating methanogen community structure and anaerobic digester function.

    Science.gov (United States)

    Bocher, B T W; Cherukuri, K; Maki, J S; Johnson, M; Zitomer, D H

    2015-03-01

    Much remains unknown about the relationships between microbial community structure and anaerobic digester function. However, knowledge of links between community structure and function, such as specific methanogenic activity (SMA) and COD removal rate, are valuable to improve anaerobic bioprocesses. In this work, quantitative structure-activity relationships (QSARs) were developed using multiple linear regression (MLR) to predict SMA using methanogen community structure descriptors for 49 cultures. Community descriptors were DGGE demeaned standardized band intensities for amplicons of a methanogen functional gene (mcrA). First, predictive accuracy of MLR QSARs was assessed using cross validation with training (n = 30) and test sets (n = 19) for glucose and propionate SMA data. MLR equations correlating band intensities and SMA demonstrated good predictability for glucose (q(2) = 0.54) and propionate (q(2) = 0.53). Subsequently, data from all 49 cultures were used to develop QSARs to predict SMA values. Higher intensities of two bands were correlated with higher SMA values; high abundance of methanogens associated with these two bands should be encouraged to attain high SMA values. QSARs are helpful tools to identify key microorganisms or to study and improve many bioprocesses. Development of new, more robust QSARs is encouraged for anaerobic digestion or other bioprocesses, including nitrification, nitritation, denitrification, anaerobic ammonium oxidation, and enhanced biological phosphorus removal. PMID:25562581

  16. TRIGA low enrichment fuel

    International Nuclear Information System (INIS)

    Sixty TRIGA reactors have been sold and the earliest of these are now passing twenty years of operation. All of these reactors use the uranium-zirconium hydride fuel (UZrH) which provides certain unique advantages arising out of its large prompt negative temperature coefficient, very low fission product release, and high temperature capability. Eleven of these Sixty reactors are conversions from plate fuel to TRIGA fuel which were made as a result of these advantages. With only a few exceptions, TRIGA reactors have always used low-enriched-uranium (LEU) fuel with an enrichment of 19.9%. The exceptions have either been converted from the standard low-enriched fuel to the 70% enriched FLIP fuel in order to achieve extended lifetime, or are higher powered reactors which were designed for long life using 93%-enriched uranium during the time when the use and export of highly enriched uranium (HEU) was not restricted. The advent of international policies focusing attention on nonproliferation and safeguards made the HEU fuels obsolete. General Atomic immediately undertook a development effort (nearly two years ago) in order to be in a position to comply with these policies for all future export sales and also to provide a low-enriched alternative to fully enriched plate-type fuels. This important work was subsequently partially supported by the U.S. Department of Energy. The laboratory and production tests have shown that higher uranium densities can be achieved to compensate for reducing the enrichment to 20%, and that the fuels maintain the characteristics of the very thoroughly proven standard TRIGA fuels. In May of 1978, General Atomic announced that these fuels were available for TRIGA reactors and for plate-type reactors with power levels up to 15 MW with GA's standard commercial warranty

  17. TRIGA low enrichment fuel

    International Nuclear Information System (INIS)

    Sixty TRIGA reactors have been sold and the earliest of these are now passing twenty years of operation. All of these reactors use the uranium zirconium hydride fuel (UZrH) which provides certain unique advantages arising out of its large prompt negative temperature coefficient, very low fission product release, and high temperature capability. Eleven of these Sixty reactors are conversions from plate fuel to TRIGA fuel which were made as a result of these advantages. With only a few exceptions, TRIGA reactors have always used low-enriched uranium (LEU) fuel with an enrichment of 19.9%. The exceptions have either been converted from the standard low-enriched fuel to the 70% enriched FLIP fuel in order to achieve extended lifetime, or are higher powered reactors which were designed for long life using 93%-enriched uranium during the time when the use and export of highly enriched uranium (HEU) was not restricted. The advent of international policies focusing attention on nonproliferation and safeguards made the HEU fuels obsolete. General Atomic immediately undertook a development effort (nearly two years ago) in order to be in a position to comply with these policies for all future export sales and also to provide a low-enriched alternative to fully enriched plate-type fuels. This important work was subsequently partially supported by the U.S. Department of Energy. The laboratory and production tests have shown that higher uranium densities can be achieved to compensate for reducing the enrichment to 20%, and that the fuels maintain the characteristics of the very thoroughly proven standard TRIGA fuels. In May of 1978, General Atomic announced that these fuels were available for TRIGA reactors and for plate-type reactors with power levels up to 15 MW with General Atomic's standard commercial warranty

  18. Performance and microbial community analysis of the anaerobic reactor with coke oven gas biomethanation and in situ biogas upgrading

    DEFF Research Database (Denmark)

    Wang, Wen; Xie, Li; Luo, Gang;

    2013-01-01

    (HFM). With pH control at 8.0, the added H2 and CO were fully consumed and no negative effects on the anaerobic degradation of sewage sludge were observed. The maximum CH4 content in the biogas was 99%. The addition of SCOG resulted in enrichment and dominance of homoacetogenetic genus Treponema......A new method for simultaneous coke oven gas (COG) biomethanation and in situ biogas upgrading in anaerobic reactor was developed in this study. The simulated coke oven gas (SCOG) (92% H2 and 8% CO) was injected directly into the anaerobic reactor treating sewage sludge through hollow fiber membrane...

  19. The effect of cyclic anaerobic-aerobic conditions on biodegradation of azo dyes.

    Science.gov (United States)

    Yaşar, Semra; Cirik, Kevser; Cinar, Ozer

    2012-03-01

    The effect of cyclic anaerobic-aerobic conditions on the biodegradative capability of the mixed microbial culture for the azo dye Remazol Brilliant Violet 5R (RBV-5R) was investigated in the sequencing batch reactor (SBR) fed with a synthetic textile wastewater. The SBR had a 12-h cycle time with anaerobic-aerobic periods of 3/9, 6/6 and 9/3 h. General SBR performance was assessed by measurement of catabolic enzymes (catechol 2,3-dioxygenase, azo reductase), chemical oxygen demand (COD), color and amount of aromatic amines. In this study, under steady-state conditions, the anaerobic period of the cyclic SBR was found to allow the reductive decolorization of azo dye. Longer anaerobic periods resulted in higher color removal efficiencies, approximately 71% for the 3-h, 87% for 6-h and 92% for the 9-h duration. Total COD removal efficiencies were over 84% under each of the cyclic conditions and increased as the length of the anaerobic period was increased; however, the highest color removal rate was attained for the cycle with the shortest anaerobic period of 3 h. During the decolorization of RBV-5R, two sulfonated aromatic amines (benzene based and naphthalene based) were formed. Additionally, anaerobic azo reductase enzyme was found to be positively affected with the increasing duration of the anaerobic period; however; it was vice versa for the aerobic catechol 2,3-dioxygenase (C23DO) enzyme.

  20. 水培条件下几种观赏植物对铅的富集特征%Enrichment Characteristics of Pb by Several Kinds of Ornamental Plants Under Hydroponic Culture

    Institute of Scientific and Technical Information of China (English)

    李翠兰; 邵泽强; 王玉军; 张晋京

    2011-01-01

    通过水培试验,研究了铅处理质量浓度为0~200 mg·L-1条件下,7种观赏植物(包括四季海棠、百日草、茶花凤仙、金鱼草、金盏菊、天竺葵和雁来红)的生长反应和富集特征.结果表明:供试观赏植物在试验的铅胁迫水平下都具有较强的耐性;四季海棠和百日草的地上部最大铅质量分数分别达到了1 229.2、1 209.7 mg·kg-1,满足超富集植物的临界质量分数标准,同时它们在试验铅处理质量浓度下的地上部铅质量分数和富集系数均显著高于其他观赏植物;四季海棠和百日草的铅转移系数最高值可达到0.9以上,并且百日草铅质量浓度在200 mg·L-1时的转移系数仍高于100 mg·L-1时的转移系数.%The growth response and enrichment characteristics of seven ornamental plants, Begonia semperflorens, Zinnia elegan, Impatiens balsamina, Antirrhinum majus, Calendula officinalis, Pelargonium hortorum and Amaranthus tricolo, were studied under hydroponic culture with 0-200 mg · L-1 of Pb. Results showed that all the tested ornamental plants had higher tolerance to Pb in the range of experimental Pb stress levels. The highest Pb mass fractions in the above-ground parts of B. semperflorens and Z. elegan were 1 229.2 and 1 209.7 mg · kg-1, respectively, which reached the critical standard of Pb hyperaccumulating plants. And the Pb mass fraction and bioaccumulation coefficient in the above-ground parts of B. semperflorens and Z. elegan was significantly higher than those of the other five ornamental plants. The highest Pb translocation factors for B. semperflorens and Z. elegan were over 0.9, and the Pb translocation factor for Z. elegan was still higher under 200 mg · L-1 than under 100 mg · L-1 of Pb.

  1. Regularities of polymer substances transformation into methane by thermophilic anaerobic bacteria

    OpenAIRE

    V. І. Karpenko; L. S. Yastremska; І. G. Burun; Y. V. Lembey; O. S. Tatarchenko

    2006-01-01

    The paper shows the regularities of polymer substances transformation into methane by extracted thermophilic anaerobic bacteria. The sequence of substrate use by the methane generating bacteria corresponds to the energy efficiency of the methane genesis reactions as in the first place hydrogen is used and then acetate is. Combined cultivation of extracted different anaerobic cultures gives the opportunity to increase ethanol and hydrogen yield as well as the effectiveness of methane formation.

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

    OpenAIRE

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

    1999-01-01

    We attempted to mimic in small upflow anaerobic sludge bed (UASB) bioreactors the metabolic association found in nature between methanogens and methanotrophs. UASB bioreactors were inoculated with pure cultures of methanotrophs, and the bioreactors were operated by using continuous low-level oxygenation in order to favor growth and/or survival of methanotrophs. Unlike the reactors in other similar studies, the hybrid anaerobic-aerobic bioreactors which we used were operated synchronously, not...

  3. Improvement of anaerobic bio-hydrogen gas production from organic sludge waste

    International Nuclear Information System (INIS)

    Microbial hydrogen gas production from organic matters stands out as one of the most promising alternatives for sustainable green energy production. Based on the literature review, investigation of anaerobic bio-hydrogen gas production from organic sludge waste using a mixed culture has been very limited. The objective of this study was to assess the anaerobic bio-hydrogen gas production from organic sludge waste under various conditions. (Author)

  4. Characterization of anaerobic chloroethene-dehalogenating activity in several subsurface sediments

    Energy Technology Data Exchange (ETDEWEB)

    Skeen, R.S.; Gao, J.; Hooker, B.S.; Quesenberry, R.D.

    1996-11-01

    Anaerobic microcosms of subsurface soils from four locations were used to investigate the separate effects of several electron donors on tetrachloroethylene (PCE) dechlorination activity. The substrates tested were methanol, formate, lactate, acetate, and sucrose. Various levels of sulfate-reducing, acetogenic, fermentative, and methanogenic activity were observed in all sediments. PCE dechlorination was detected in all microcosms, but the amount of dehalogenation varied by several orders of magnitude. Trichloroethylene was the primary dehalogenation product; however, small amounts of cis-1,2-dichloroethylene, 1,1-dichloroethylene, and vinyl chloride were also detected in several microcosms. Lactate-amended microcosms showed large amounts of dehalogenation. in three of the four sediments. One of the two sediments which showed positive activity with lactate also had large amounts of delialogenation with methanol. Sucrose, formate, and acetate also stimulated large amounts of delialogenation in one sediment that showed activity with lactate. These results suggest that lactate may be an appropriate substrate for screening sediments for PCE or TCE delialogenation activity, but that the microbial response is not sufficient for complete in situ bioremediation. A detailed study of the Victoria activity revealed that delialogenation rates were more similar to the Cornell culture than to rates measured for methanogens, or a methanol-enriched sediment culture. This may suggest that these sediments contain a highly efficient delialogenation activity similar to the Cornell culture. This assertion is supported further by the fact that an average of 3% of added reducing equivalents could be diverted to dehalogenation in tests which were conducted using PCE-saturated hexadecane as a constant source of PCE during incubation. Further evidence is needed to confirm this premise. The application of these results to in situ bioremediation of highly contaminated areas are discussed.

  5. Degradation of TCE using sequential anaerobic biofilm and aerobic immobilized bed reactor

    Science.gov (United States)

    Chapatwala, Kirit D.; Babu, G. R. V.; Baresi, Larry; Trunzo, Richard M.

    1995-01-01

    Bacteria capable of degrading trichloroethylene (TCE) were isolated from contaminated wastewaters and soil sites. The aerobic cultures were identified as Pseudomonas aeruginosa (four species) and Pseudomonas fluorescens. The optimal conditions for the growth of aerobic cultures were determined. The minimal inhibitory concentration values of TCE for Pseudomonas sps. were also determined. The aerobic cells were immobilized in calcium alginate in the form of beads. Degradation of TCE by the anaerobic and dichloroethylene (DCE) by aerobic cultures was studied using dual reactors - anaerobic biofilm and aerobic immobilized bed reactor. The minimal mineral salt (MMS) medium saturated with TCE was pumped at the rate of 1 ml per hour into the anaerobic reactor. The MMS medium saturated with DCE and supplemented with xylenes and toluene (3 ppm each) was pumped at the rate of 1 ml per hour into the fluidized air-uplift-type reactor containing the immobilized aerobic cells. The concentrations of TCE and DCE and the metabolites formed during their degradation by the anaerobic and aerobic cultures were monitored by GC. The preliminary study suggests that the anaerobic and aerobic cultures of our isolates can degrade TCE and DCE.

  6. Aerobic and Anaerobic Starvation Metabolism in Methanotrophic Bacteria

    OpenAIRE

    Roslev, P.; King, G. M.

    1995-01-01

    The capacity for anaerobic metabolism of endogenous and selected exogenous substrates in carbon- and energy-starved methanotrophic bacteria was examined. The methanotrophic isolate strain WP 12 survived extended starvation under anoxic conditions while metabolizing 10-fold less endogenous substrate than did parallel cultures starved under oxic conditions. During aerobic starvation, the cell biomass decreased by 25% and protein and lipids were the preferred endogenous substrates. Aerobic prote...

  7. Solubilization of lignin by the ruminal anaerobic fungus Neocallimastix patriciarum.

    OpenAIRE

    McSweeney, C S; Dulieu, A; Katayama, Y; Lowry, J B

    1994-01-01

    The ability of the ruminal anaerobic phycomycete Neocallimastix patriciarum to digest model lignin compounds and lignified structures in plant material was studied in batch culture. The fungus did not degrade or transform model lignin compounds that were representative of the predominant intermonomer linkages in lignin, nor did it solubilize acid detergent lignin that had been isolated from spear grass. In a stem fraction of sorghum, 33.6% of lignin was apparently solubilized by the fungus. S...

  8. Xylitol Production From D-Xylose by Facultative Anaerobic Bacteria

    OpenAIRE

    Rangaswamy, Sendil

    2003-01-01

    Seventeen species of facultative anaerobic bacteria belonging to three genera (Serratia, Cellulomonas, and Corynebacterium) were screened for the production of xylitol; a sugar alcohol used as a sweetener in the pharmaceutical and food industries. A chromogenic assay of both solid and liquid cultures showed that 10 of the 17 species screened could grow on D-xylose and produce detectable quantities of xylitol during 24-96 h of fermentation. The ten bacterial species were studied for the effe...

  9. Growth of a Strictly Anaerobic Bacterium on Furfural (2-Furaldehyde)

    OpenAIRE

    Brune, Gerhard; Schoberth, Siegfried M.; Sahm, Hermann

    1983-01-01

    A strictly anaerobic bacterium was isolated from a continuous fermentor culture which converted the organic constituents of sulfite evaporator condensate to methane and carbon dioxide. Furfural is one of the major components of this condensate. This furfural isolate could degrade furfural as the sole source of carbon and energy in a defined mineral-vitamin-sulfate medium. Acetic acid was the major fermentation product. This organism could also use ethanol, lactate, pyruvate, or fumarate and c...

  10. Isotope fractionation during the anaerobic consumption of acetate by methanogenic and sulfate-reducing microorganisms

    Science.gov (United States)

    Gövert, D.; Conrad, R.

    2009-04-01

    During the anaerobic degradation of organic matter in anoxic sediments and soils acetate is the most important substrate for the final step in production of CO2 and/or CH4. Sulfate-reducing bacteria (SRB) and methane-producing archaea both compete for the available acetate. Knowledge about the fractionation of 13C/12C of acetate carbon by these microbial groups is still limited. Therefore, we determined carbon isotope fractionation in different cultures of acetate-utilizing SRB (Desulfobacter postgatei, D. hydrogenophilus, Desulfobacca acetoxidans) and methanogens (Methanosarcina barkeri, M. acetivorans). Including literature values (e.g., Methanosaeta concilii), isotopic enrichment factors (epsilon) ranged between -35 and +2 permil, possibly involving equilibrium isotope effects besides kinetic isotope effects. The values of epsilon were dependent on the acetate-catabolic pathway of the particular microorganism, the methyl or carboxyl position of acetate, and the relative availability or limitation of the substrate acetate. Patterns of isotope fractionation in anoxic lake sediments and rice field soil seem to reflect the characteristics of the microorganisms actively involved in acetate catabolism. Hence, it might be possible using environmental isotopic information to determine the type of microbial metabolism converting acetate to CO2 and/or CH4.

  11. Consideration and development of anaerobic fermentation equipment on solid organic rejectamenta

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This article, based on investigation and analysis, existed anaerobic fermentation equipment, with a view to the production of high-latitude area, pointed out the thought of exploiting efficient anaerobic fermentation equipment, including: the settling independent equipment of acidogenic phase and methanogenic phase; the applying conbination of AF and UASB in methanogenic phase; adopting efficient sludge inverse flowing equipment and the technique of flora enrichment, and efficient method of saving energy and thermal retardation; adopting autocontrol which could make the equipment run efficiently and stably.

  12. Enrichment: Dealing with overcapacity

    International Nuclear Information System (INIS)

    Today's surplus of enrichment capacity will continue until at least the end of this century. This will challenge the ingenuity of the separative work unit (SWU) suppliers as they attempt to keep market share and remain profitable in a very competitive marketplace. The utilities will be faced with attractive choices, but making the best choice will require careful analysis and increased attention to market factors. Current demand projections will probably prove too high to the extent that more reactors are canceled or delayed. The DOE has the vast majority of the unused capacity, so it will feel the most immediate impact of this large surplus in productive capacity. The DOE has responded to these market challenges by planning another reorganization of its enriching operations. Without a major agreement among the governments affected by the current surplus in enrichment capacity, the future will see lower prices, more competitive terms, and the gradual substitution of centrifuge or laser enrichment for the gaseous diffusion plants. The competition that is forcing the gaseous diffusion prices down to marginal cost will provide the long-term price basis for the enrichment industry

  13. Arsenic, Anaerobes, and Astrobiology

    Science.gov (United States)

    Stolz, J. F.; Oremland, R. S.; Switzer Blum, J.; Hoeft, S. E.; Baesman, S. M.; Bennett, S.; Miller, L. G.; Kulp, T. R.; Saltikov, C.

    2013-12-01

    Arsenic is an element best known for its highly poisonous nature, so it is not something one would associate with being a well-spring for life. Yet discoveries made over the past two decades have delineated that not only are some microbes resistant to arsenic, but that this element's primary redox states can be exploited to conserve energy and support prokaryotic growth ('arsenotrophy') in the absence of oxygen. Hence, arsenite [As(III)] can serve as an electron donor for chemo- or photo-autotrophy while arsenate [As(V)] will serve as an electron acceptor for chemo-heterotrophs and chemo-autotrophs. The phylogenetic diversity of these microbes is broad, encompassing many individual species from diverse taxonomic groups in the Domain Bacteria, with fewer representatives in the Domain Archaea. Speculation with regard to the evolutionary origins of the key functional genes in anaerobic arsenic transformations (arrA and arxA) and aerobic oxidation (aioB) has led to a disputation as to which gene and function is the most ancient and whether arsenic metabolism extended back into the Archaean. Regardless of its origin, robust arsenic metabolism has been documented in extreme environments that are rich in their arsenic content, such as hot springs and especially hypersaline soda lakes associated with volcanic regions. Searles Lake, CA is an extreme, salt-saturated end member where vigorous arsenic metabolism occurs, but there is no detectable sulfate-reduction or methanogenesis. The latter processes are too weak bio-energetically to survive as compared with arsenotrophy, and are also highly sensitive to the abundance of borate ions present in these locales. These observations have implications with respect to the search for microbial life elsewhere in the Solar System where volcanic-like processes have been operative. Hence, because of the likelihood of encountering dense brines in the regolith of Mars (formed by evapo-concentration) or beneath the ice layers of Europa

  14. Anaerobic Digestion of Piggery Waste

    OpenAIRE

    Velsen, van, L.S.

    1981-01-01

    Anaerobic digestion is a biological process by which organic matter is converted to methane and carbon dioxide by microbes in the absence of air (oxygen). In nature, anaerobic conversions occur at all places where organic material accumulates and the supply of oxygen is deficient, e.g. in marshes and lake sediments. Microbial formation of methane also plays a role in the ruminant digestion.In digestion units, the external conditions acting upon the process can be regulated to speed it up as c...

  15. Oxygen enrichment incineration

    International Nuclear Information System (INIS)

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested

  16. Oxygen enrichment incineration

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

    2000-10-01

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested.

  17. Molecular genetic studies on obligate anaerobic bacteria

    International Nuclear Information System (INIS)

    Molecular genetic studies on obligate anaerobic bacteria have lagged behind similar studies in aerobes. However, the current interest in biotechnology, the involvement of anaerobes in disease and the emergence of antibioticresistant strains have focused attention on the genetics of anaerobes. This article reviews molecular genetic studies in Bacteroides spp., Clostridium spp. and methanogens. Certain genetic systems in some anaerobes differ from those in aerobes and illustrate the genetic diversity among bacteria

  18. Laser and gas centrifuge enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Heinonen, Olli [Senior Fellow, Belfer Center for Science and International Affairs, Harvard Kennedy School, Cambridge, Massachusetts (United States)

    2014-05-09

    Principles of uranium isotope enrichment using various laser and gas centrifuge techniques are briefly discussed. Examples on production of high enriched uranium are given. Concerns regarding the possibility of using low end technologies to produce weapons grade uranium are explained. Based on current assessments commercial enrichment services are able to cover the global needs of enriched uranium in the foreseeable future.

  19. Laser and gas centrifuge enrichment

    Science.gov (United States)

    Heinonen, Olli

    2014-05-01

    Principles of uranium isotope enrichment using various laser and gas centrifuge techniques are briefly discussed. Examples on production of high enriched uranium are given. Concerns regarding the possibility of using low end technologies to produce weapons grade uranium are explained. Based on current assessments commercial enrichment services are able to cover the global needs of enriched uranium in the foreseeable future.

  20. Measuring metal and phosphorus speciation in P-rich anaerobic digesters.

    Science.gov (United States)

    Carliell-Marquet, C M; Wheatley, A D

    2002-01-01

    High concentrations of soluble orthophosphate, magnesium and potassium are released during anaerobic digestion of biological phosphorus removal (BPR) sludge. This research was undertaken to investigate the effects of phosphorus enrichment on digester performance, metal and phosphorus speciation. High concentrations of soluble PO4-P (> 250 mg/l) were found to have a retarding effect on anaerobic digestion, reducing the rate of volatile solids digestion and methane production in comparison to control digesters. This was found to be reversible after a period of time, which was related to the amount of PO4-P added to the digesters, higher concentrations of PO4-P requiring more time for digester recovery. Addition of magnesium and potassium to the digesters, together with PO4-P, reduced the inhibitory effect of phosphorus enrichment but these digesters still showed lower rates of volatile solids digestion and methane production in comparison to the control digesters. Phosphorus enrichment resulted in extensive precipitation of calcium, magnesium and manganese, markedly reducing the soluble and easily available fractions of these metals. Other trace metals such as copper, zinc, chromium, nickel and cobalt actually showed increased levels of solubility as a result of phosphorus enrichment. This was thought to be caused by high levels of soluble organic carbon in the phosphorus-rich anaerobic digesters, which acted as organic ligands for metal complexation. PMID:12188563

  1. Segal Enriched Categories I

    CERN Document Server

    Bacard, Hugo V

    2010-01-01

    We develop a theory of enriched categories over a (higher) category M equipped with a class W of morphisms called homotopy equivalences. We call them Segal M_W -categories. Our motivation was to generalize the notion of "up-to-homotopy monoids" in a monoidal category M, introduced by Leinster. The formalism adopted generalizes the classical Segal categories and extends the theory of enriched category over a bicategory. In particular we have a linear version of Segal categories which did not exist so far. Our goal in this paper is to present the theory and provide some examples. Applications are reserved for the future.

  2. Advanced uranium enrichment processes

    International Nuclear Information System (INIS)

    Three advanced Uranium enrichment processes are dealt with in the report: AVLIS (Atomic Vapour LASER Isotope Separation), MLIS (Molecular LASER Isotope Separation) and PSP (Plasma Separation Process). The description of the physical and technical features of the processes constitutes a major part of the report. If further presents comparisons with existing industrially used enrichment technologies, gives information on actual development programmes and budgets and ends with a chapter on perspectives and conclusions. An extensive bibliography of the relevant open literature is added to the different subjects discussed. The report was drawn up by the nuclear research Centre (CEA) Saclay on behalf of the Commission of the European Communities

  3. Bacterial community succession during the enrichment of chemolithoautotrophic arsenite oxidizing bacteria at high arsenic concentrations

    Institute of Scientific and Technical Information of China (English)

    Nguyen Ai Le; Akiko Sato; Daisuke Inoue; Kazunari Sei; Satoshi Soda; Michihiko Ike

    2012-01-01

    To generate cost-effective technologies for the removal of arsenic from water,we developed an enrichment culture of chemolithoautotrophic arsenite oxidizing bacteria (CAOs) that could effectively oxidize widely ranging concentrations of As(Ⅲ) to As(Ⅴ).In addition,we attempted to elucidate the enrichment process and characterize the microbial composition of the enrichment culture.A CAOs enrichment culture capable of stably oxidizing As(Ⅲ) to As(Ⅴ) was successfully constructed through repeated batch cultivation for more than 700 days,during which time the initial As(Ⅲ) concentrations were increased in a stepwise manner from l to 10-12 mmol/L.As(Ⅲ) oxidation activity of the enrichment culture gradually improved,and 10-12 mmol/L As(Ⅲ) was almost completely oxidized within four days.Terminal restriction fragment length polymorphism analysis showed that the dominant bacteria in the enrichment culture varied drastically during the enrichment process depending on the As(Ⅲ) concentration.Isolation and characterization of bacteria in the enrichment culture revealed that the presence of multiple CAOs with various As(Ⅲ) oxidation abilities enabled the culture to adapt to a wide range of As(Ⅲ) concentrations.The CAOs enrichment culture constructed here may he useful for pretreatment of water from which arsenic is being removed.

  4. The phenomenon of granulation of anaerobic sludge.

    NARCIS (Netherlands)

    Hulshoff Pol, L.W.

    1989-01-01

    Successful high-rate anaerobic wastewater treatment can only be accomplished when the slowgrowing anaerobic biomass is efficiently held back in the anaerobic treatment system. This biomass retention can be achieved in various ways including immobilization of the organisms on fixed materials and immo

  5. Viscosity evolution of anaerobic granular sludge

    NARCIS (Netherlands)

    Pevere, A.; Guibaud, G.; Hullebusch, van E.D.; Lens, P.N.L.; Baudu, M.

    2006-01-01

    The evolution of the apparent viscosity at steady shear rate of sieved anaerobic granular sludge (20¿315 ¿m diameter) sampled from different full-scale anaerobic reactors was recorded using rotation tests. The ¿limit viscosity¿ of sieved anaerobic granular sludge was determined from the apparent vis

  6. Kinetics and modeling of anaerobic digestion process

    DEFF Research Database (Denmark)

    Gavala, Hariklia N.; Angelidaki, Irini; Ahring, Birgitte Kiær

    2003-01-01

    Anaerobic digestion modeling started in the early 1970s when the need for design and efficient operation of anaerobic systems became evident. At that time not only was the knowledge about the complex process of anaerobic digestion inadequate but also there were computational limitations. Thus, th...

  7. Microbial Diversity and Characteristics in Anaerobic Environments in KURT Groundwater

    International Nuclear Information System (INIS)

    The Underground Research Tunnel (URT) located in Korea Atomic Energy Research Institute (KAERI), Daejeon, South Korea was recently constructed as an experimental site to study radionuclide transport, biogeochemistry, radionuclide-mineral interactions for the geological disposal of high level nuclear waste. Groundwater sampled from URT was used to examine microbial diversity and to enrich metal reducing bacteria for studying microbe-metal interactions. Genomic analysis indicated that the groundwater contained diverse microorganisms such as metal reducers, metal oxidizers, anaerobic denitrifying bacteria, and bacteria for reductive dechlorination. Metal-reducing bacteria enriched from the groundwater was used to study metal reduction and biomineralization. The metal-reducing bacteria enriched with acetate or lactate as the electron donors showed the bacteria reduced Fe(III)-citrate, Fe(III) oxyhydroxide, Mn(IV) oxide, and Cr(VI) as the electron acceptors. Preliminary study indicated that the enriched bacteria were able to use glucose, lactate, acetate, and hydrogen as electron donors while reducing Fe(III)-citrate or Fe(III) oxyhydroxide as the electron acceptor. The bacteria exhibited diverse mineral precipitation capabilities including the formation of magnetite, siderite, and rhodochrosite. The results indicated that Fe(III)- and metal-reducing communities are present in URT at the KAERI

  8. Designing job enrichment projects.

    Science.gov (United States)

    Clakeley, G L

    1988-01-01

    This paper describes a management strategy for a job satisfaction program utilized in a large occupational therapy department. The goal of the program is to retain satisfied, productive employees and reduce attrition of therapists and assistants. The use of job enrichment projects for occupational therapy assistants will be presented with brief descriptions of two projects. PMID:23944880

  9. Job Enrichment in Extension.

    Science.gov (United States)

    Fourman, Louis S.; Jones, Jo

    1997-01-01

    Interviews with 10 participants in Ohio State University's job enrichment program for midcareer extension agents found that 5 returned to their same jobs after the experience but only 2 felt challenged/renewed. Part-time participation while working made it difficult to balance responsibilities. More information and a structured orientation were…

  10. Enriching the Catalog

    Science.gov (United States)

    Tennant, Roy

    2004-01-01

    After decades of costly and time-consuming effort, nearly all libraries have completed the retrospective conversion of their card catalogs to electronic form. However, bibliographic systems still are really not much more than card catalogs on wheels. Enriched content that Amazon.com takes for granted--such as digitized tables of contents, cover…

  11. Methodology for content enrichment

    NARCIS (Netherlands)

    Nederbragt, H.; Heerlien, M.

    2010-01-01

    The STERNA project mainly focuses on enrichment of existing content of content holding organisations in the natural history domain. Therefore, developing a methodology on how to best integrate one’s content into the STERNA information space is an essential part of the project. This document is the o

  12. Anaerobic Treatment of Methanolic Wastes

    NARCIS (Netherlands)

    Lettinga, G.; Geest, van der A.Th.; Hobma, S.W.; Laan, van der J.B.R.

    1979-01-01

    Although it is well known that methanol can be fermented directly by a specific species of methane bacteria, viz. Methanosarcina barkeri, until now little information was available about the effect of important environmental factors on the anaerobic fermentation of methanol. As methanol can be the m

  13. Anaerobic nitrite-dependent methane-oxidizing bacteria - novel participants in methane cycling of drained peatlands ecosystems

    Science.gov (United States)

    Kravchenko, Irina; Sukhacheva, Marina; Menko, Ekaterina; Sirin, Andrey

    2014-05-01

    amplification of 16S rRNA (Ettwig et al. 2009) and pmoA (Luesken et al. 2011) genes followed by construction of clone libraries. Phylogenetic analysis revealed only one n-damo bacterium distantly related to uncultured anaerobic methanotrophs found in situ. It may represent a new cluster of NC10 bacteria with an identity of less than 96 and 86% to the 16S rRNA and pmoA genes of "Ca. Methylomirabilis oxyfera," respectively. An enrichment of nitrite-reducing methanotrophic NC10 bacteria was successfully obtained from this sample in a static anaerobic culture with methane and nitrite at an in situ pH of 6.3. The bacterial abundance in enrichment was estimated using quantitative PCR and FISH (DBACT-0193-a-A probe) analysis and was found to increase up to 10 times for 120 days. The results of this study expand our knowledge of the diversity and distribution of NC10 bacteria in the environment and their potential contribution to nitrogen and methane cycles in northern peatland ecosystems. We think that AOM may be more active in anthropogenic disturbed peatlands with greater supply of elements that could potentially serve as electron acceptors. In spite of generally low concentration, seasonal increases in nitrate content in drained peatlands may work as an important control of CH4 fluxes. The study was partially supported by RFBR research project # 12-05-01029_a.

  14. Anaerobic granular sludge and biofilm reactors

    DEFF Research Database (Denmark)

    Skiadas, Ioannis V.; Gavala, Hariklia N.; Schmidt, Jens Ejbye;

    2003-01-01

    by the immobilization of the biomass, which forms static biofilms, particle-supported biofilms, or granules depending on the reactor's operational conditions. The advantages of the high-rate anaerobic digestion over the conventional aerobic wastewater treatment methods has created a clear trend for the change......-rate anaerobic treatment systems based on anaerobic granular sludge and biofilm are described in this chapter. Emphasis is given to a) the Up-flow Anaerobic Sludge Blanket (UASB) systems, b) the main characteristics of the anaerobic granular sludge, and c) the factors that control the granulation process...

  15. Transient characteristics of Paracoccus denitrificans with changes between aerobic and anaerobic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Waki, T.; Murayama, K.; Kawato, Y.; Ichikawa, K.

    1980-06-01

    The growth characteristics of Paracoccus denitrificans in both aerobic and anaerobic conditions and in the transient phase from aerobic to anaerobic conditions and vice versa were studied in batch and continuous cultures. The growth yield coefficients for glucose and the maximum specific growth rate were 0.59 (g cell/g glucose) and 0.49 (1/hr), and 0.41 (g cell/g glucose) and 0.23 (1/hr) in aerobic and anaerobic conditions, respectively. The nitrate reductase activities in an anaerobic continuous culture were almost constant irrespective of the growth rate and the enzymes were considered to be present in excess. Most of the nitrate reductase activity observed under aerobic conditions using the medium without ammonium chloride was due to the assimilative nitrate reductase. On the transition from anaerobic to aerobic conditions, the nitrate reductase activity was inhibited by the oxygen and the reduction of nitrate was stopped. When the conditions were changed from aerobic to anaerobic the glucose consumption and the growth stopped for a few hours and the nitrate reductase activity started to increase, however, the initial rapid reduction of nitrate and the accumulation of nitrite were observed. The nitrite reductase activity started to increase after the nitrite accumulated to a high concentration. The high efficiency of nitrogen removal in the single sludge nitrification-denitrification system was considered to be attributed to the initial rapid reduction of nirate during the transient phase in spite of the long adaptation lag for denitrification.

  16. The hydrogenosomal malic enzyme from the anaerobic fungus Neocallimastix frontalis is targeted to mitochondria of the methylotrophic yeast Hansenula polymorpha

    NARCIS (Netherlands)

    van der Giezen, M; Kiel, J.A.K.W.; Sjollema, K.A; Prins, R.A

    1998-01-01

    Hydrogenosomal proteins always contain an amino-terminal extension which is believed to be a hydrogenosomal targeting signal. In the anaerobic fungus Neocallimastix frontalis these putative targeting signals are 27 amino acids long, are enriched in Ala, Leu, Ser and Arg, and have an Arg at position

  17. Biohydrogen production from rotten orange with immobilized mixed culture: Effect of immobilization media for various composition of substrates

    Science.gov (United States)

    Damayanti, Astrilia; Sarto, Syamsiah, Siti; Sediawan, Wahyudi B.

    2015-12-01

    Enriched-immobilized mixed culture was utilized to produce biohydrogen in mesophilic condition under anaerobic condition using rotten orange as substrate. The process was conducted in batch reactors for 100 hours. Microbial cultures from three different sources were subject to a series of enrichment and immobilized in two different types of media, i.e. calcium alginate (CA, 2%) and mixture of alginate and activated carbon (CAC, 1:1). The performance of immobilized culture in each media was tested for biohydrogen production using four different substrate compositions, namely orange meat (OM), orange meat added with peel (OMP), orange meat added with limonene (OML), and mixture of orange meat and peel added with limonene (OMPL). The results show that, with immobilized culture in CA, the variation of substrate composition gave significant effect on the production of biohydrogen. The highest production of biohydrogen was detected for substrate containing only orange meet, i.e. 2.5%, which was about 3-5 times higher than biohydrogen production from other compositions of substrate. The use of immobilized culture in CAC in general has increased the hydrogen production by 2-7 times depending on the composition of substrate, i.e. 5.4%, 4.8%, 5.1%, and 4.4% for OM, OMP, OML, and OMPL, respectively. The addition of activated carbon has eliminated the effect of inhibitory compounds in the substrate. The major soluble metabolites were acetic acid, propionic acid, and butyric acid.

  18. Effect of incubation conditions on anaerobic susceptibility testing results.

    OpenAIRE

    Murray, P R; Niles, A C

    1982-01-01

    We determined the effect of performing antimicrobial susceptibility tests in five different anaerobic incubation systems: GasPak jar, large GasPak jar, evacuated-gassed anaerobic jar, anaerobic chamber, and Bio-Bag. Growth of the anaerobes was equivalent in all five incubation systems. The results of testing 38 anaerobes against 11 antimicrobial agents were comparable for the anaerobic jars and anaerobic chamber. However, discordant results were observed for metronidazole and cefamandole test...

  19. Polyphasic characterization of a PCP-to-phenol dechlorinating microbial community enriched from paddy soil

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Naoko [EcoTopia Science Institute, Nagoya University Nagoya 464-8603 (Japan)]. E-mail: ysd75@esi.nagoya-u.ac.jp; Yoshida, Yukina [Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan); Handa, Yuko [Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan); Kim, Hyo-Keun [Korea Ginseng and Tobacco Research Institute, Taejon 305-345 (Korea, Republic of); Ichihara, Shigeyuki [Faculty of Agriculture, Meijo University, Nagoya 468-8502 (Japan); Katayama, Arata [EcoTopia Science Institute, Nagoya University Nagoya 464-8603 (Japan); Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan)

    2007-08-01

    Dechlorination of PCP has been observed previously under anaerobic condition in paddy soil. However, there is poor information about the dechlorination pathway of PCP and the microbial community associated with the PCP dechlorination in paddy soil. In this study, an anaerobic microbial community dechlorinating PCP was enriched by serial transfers from a paddy soil using a medium containing PCP, lactate and the steam-sterilized paddy soil. The enriched microbial community dechlorinated PCP completely to phenol under the anaerobic condition by a dechlorinating pathway as follows; PCP {sup {yields}} 2,3,4,5-tetrachlorophenol {sup {yields}} 3,4,5-trichlorophenol {sup {yields}} 3,5-dichlorophenol {sup {yields}} 3-chlorophenol {sup {yields}} phenol. Intermediate products such as 3-chlorophenol were not accumulated, which were immediately dechlorinated to phenol. The enriched microbial community was characterized physiologically by testing the effects of electron donors and electron acceptors on the dechlorinating activity. The dechlorinating activity was promoted with lactate, pyruvate, and hydrogen as electron donors but not with acetate. Electron acceptors, nitrate and sulphate, inhibited the dechlorinating activity competitively but not iron (III). The microbial group associated with the anaerobic dechlorination was characterized by the effect of specific inhibitors on the PCP dechlorination. Effects of specific metabolic inhibitors and antibiotics indicated the involvement of Gram-positive spore-forming bacteria with the PCP dechlorinating activity, which was represented as bacteria of phylum Firmicutes. The structure of the microbial community was characterized by fluorescence in situ hybridization, quinone profiling, and PCR-DGGE (denaturing gel gradient electrophoresis). The combined results indicated the predominance of Clostridium species of phylum Firmicutes in the microbial community. Desulfitobacterium spp. known as anaerobic Gram-positive spore

  20. Anaerobic degradation of benzoate by sulfate-reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Silva, S.P.; Adorno, M.A.T.; Moraes, E.M.; Varesche, M.B.A. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Biological Processes Laboratory

    2004-07-01

    Anaerobic processes are an efficient way to degrade aromatic compounds in industrial wastewater, such as phenol, cresol and benzoate. This study characterized the bacteria that degrades benzoate, an anaerobic degradation intermediate of several complex aromatic compounds. In particular, the study assessed the capacity to use benzoate with sulfate reducing bacteria in mesophilic conditions. Biofilm from polyurethane foam matrices of a fixed bed reactor was used as the cellular inoculum to treat industrial wastewater containing organic peroxide. Dilution techniques were used to purify the material and obtain cultures of cocci. The benzoate consumption capacity in sulfidogenic conditions was observed when the purified inoculum was applied to batch reactors with different benzoate/sulfate relations. Results indicate that purification was positive to bacteria that can degrade aromatic compounds. Desulfococcus multivorans bacteria was identified following the physiologic and kinetic experiments. The 0.6 benzoate/sulfate relation was considered ideal for complete consumption of carbon and total use of sulfur. 10 refs., 3 figs.

  1. Enrichment of Methane-Utilizing Mixed Culture with a High Polyβ-Hydroxybutyrat Content in an Open System%开放条件下高聚3-羟基丁酸酯含量的甲烷氧化混合茵群的富集

    Institute of Scientific and Technical Information of China (English)

    姜丹; 董静; 辛嘉英; 张莹莹; 张颖鑫; 夏春谷

    2011-01-01

    Objective: To enrich a methane-utilizing mixed culture with a high poly-p-hydroxybutyrate (PHB) content using methane as substrate in an open system, then obtain microbial species of high PHB content at low carbon cost. Methods: The method of feast-famine aerobic dynamic feeding was used to cultivate methane-utilizing mixed culture using methane as substrate in an open system, and the effect of feast-famine ratio on enriching mixed culture with a high PHB content was studied based on sudan black staining. Results: The PHB content in biomass increased from 17.7% to 35.5% when the feast-famine ratio was 1:3, and the structure of mixed culture was stable in an open system. Conclusion: Methane-Utilizing mixed culture enriched by the method of feast-famine aerobic dynamic feeding has the application value for commercial PHB production.%目的:在开放条件下以甲烷为底物富集高聚β-羟基丁酸酯(PHB)含量的甲烷氧化菌群,获得能够利用低成本碳源高产PHB的菌种.方法:采用丰盛-饥饿模式间歇供料,以甲烷为底物,好氧开放式培养甲烷氧化混合菌群,利用苏丹黑染色法动态检测丰盛和饥饿阶段胞内PHB含量的变化,以此为基础考察丰盛-饥饿期比例对富集高PHB含量的甲烷氧化菌群的影响.结果:丰盛-饥饿期比例为1:3时,微生物PHB含量从17.7%增加到35.5%,且开放培养过程中菌群结构稳定.结论:通过丰盛-饥饿模式间歇供料开放式培养所得的高PHB含量的稳定的甲烷氧化菌群,具有工业生产PHB的应用价值.

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

    Science.gov (United States)

    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

  3. Enrichment marketplace - today (and tomorrow)

    International Nuclear Information System (INIS)

    The technologies and capacities of the four primary sources of enrichment services, the United States Department of Energy, Eurodif, Techsnabexport of the Soviet Union, and Urenco, were given. Forecasts of future capacities and prices of enriched uranium were also included

  4. Methanogenic and Other Strictly Anaerobic Bacteria in Desert Soil and Other Oxic Soils

    OpenAIRE

    Peters, V; Conrad, R.

    1995-01-01

    Strictly anaerobic bacteria such as methanogenic, sulfate-reducing, and homoacetogenic bacteria could be enriched from all five oxic soils tested. The number of cells was lower than that in typical anoxic habitats. Spores did not always dominate the population of sulfate-reducing bacteria. In all soils, the methanogenic population displayed a long lag phase after anoxic conditions were imposed before methane production began.

  5. Anaerobic digestion of solid material

    DEFF Research Database (Denmark)

    Vavilin, V.A.; Lokshina, L.Y.; Flotats, X.;

    2007-01-01

    A new multidimensional (3 and 2D) anaerobic digestion model for cylindrical reactor with non-uniform influent concentration distributions was developed to study the way in which mixing intensity affects the efficiency of continuous-flow anaerobic digestion. Batch experiments reported and simulated...... earlier by Vavilin and Angelidaki (2005) were used to modernize a kinetic scheme and to obtain the corresponding kinetic coefficients. In the new models, hydrolytic microorganisms were included using Contois kinetics for the hydrolysis/acidogenesis degradation of municipal solid waste (MSW). Monod...... kinetics was applied for description of methanogenesis. Both hydrolytic and methanogenic microorganisms were assumed to be inhibited by high volatile fatty acids (VFA) concentration. According to the new distributed models, the mixing level reduction expressed by increasing dimensionless Peclet number may...

  6. Anaerobic procedures of wastewater treatment

    OpenAIRE

    Zupančič, Tadeja

    2013-01-01

    Highly polluted wastewater is formed in dairies, pig farms and slaughterhouses. Before released into watercourses, wastewater should be properly processed with different treatment procedures in wastewater treatment plants. The thesis deals with the descriptions of mechanical, physical and chemical, and biological wastewater treatment procedures and the description of the factors which affect the reactions in wastewater treatment plants. I give special emphasis on anaerobic wastewater treatmen...

  7. Anaerobic digestion of aliphatic polyesters.

    Science.gov (United States)

    Šmejkalová, Pavla; Kužníková, Veronika; Merna, Jan; Hermanová, Soňa

    2016-01-01

    Anaerobic processes for the treatment of plastic materials waste represent versatile and effective approach in environmental protection and solid waste management. In this work, anaerobic biodegradability of model aliphatic polyesters, poly(L-lactic acid) (PLA), and poly(ɛ-caprolactone) (PCL), in the form of powder and melt-pressed films with varying molar mass, was studied. Biogas production was explored in batch laboratory trials at 55 ± 1°C under a nitrogen atmosphere. The inoculum used was thermophilic digested sludge (total solids concentration of 2.9%) from operating digesters at the Central Waste Water Treatment Plant in Prague, Czech Republic. Methanogenic biodegradation of PCLs typically yielded from 54 to 60% of the theoretical biogas yield. The biodegradability of PLAs achieved from 56 to 84% of the theoretical value. High biogas yield (up to 677 mL/g TS) with high methane content (more than 60%), comparable with conventionally processed materials, confirmed the potential of polyester samples for anaerobic treatment in the case of their exploitation in agriculture or as a packaging material in the food industry. PMID:27191559

  8. The Effect of Anaerobic and Aerobic Fish Sludge Supernatant on Hydroponic Lettuce

    Directory of Open Access Journals (Sweden)

    Simon Goddek

    2016-06-01

    Full Text Available The mobilization of nutrients from fish sludge (i.e., feces and uneaten feed plays a key role in optimizing the resource utilization and thus in improving the sustainability of aquaponic systems. While several studies have documented the aerobic and anaerobic digestion performance of aquaculture sludge, the impact of the digestate on plant growth has yet to be understood. The present study examines the impact of either an aerobic or an anaerobic digestion effluent on lettuce plant growth, by enriching a mixture of aquaculture and tap water with supernatants from both aerobic and anaerobic batch reactors. The lettuce plants grown in the hydroponic system supplied with supernatant from an anaerobic reactor had significantly better performance with respect to weight gain than both, those in the system where supernatant from the aerobic reactor was added, as well as the control system. It can be hypothesized that this effect was caused by the presence of NH4+ as well as dissolved organic matter, plant growth promoting rhizobacteria and fungi, and humic acid, which are predominantly present in anaerobic effluents. This study should therefore be of value to researchers and practitioners wishing to further develop sludge remineralization in aquaponic systems.

  9. Isolation of aerobic and anaerobic bacteria from suspected enterotoxaemia cases in lambs

    Directory of Open Access Journals (Sweden)

    N. S. Mechael

    2012-01-01

    Full Text Available Ninety cases of clinically diagnosed enterotoxemia infection in lambs at AL-Hamdaniya region where studied for isolation of aerobic and anaerobic bacterial causes, faecal samples were collected from all suspected cases during January- June 2008, the results show that 41.6% of the isolates were Cl. perfringens as pure single isolates, while mixed infection of Cl. perfringens with each of Enterococci and staphylococcus in percentage of 26.04%, 20.83% respectively, also mixed infection of Cl. septicum with each of Staphylococcus and E.coli were isolated at the percentage of 5.2%, 6.25% respectively. Highest bacterial isolation was from the faecal samples collected during April. McIntosh jar method show isolation of pure culture of anaerobic bacteria (Cl. perfringens, while Candle jar method show detection of 56 isolates in mixed cultures of aerobic and anaerobic bacteria.

  10. Boosting dark fermentation with co-cultures of extreme thermophiles for biohythane production from garden waste.

    Science.gov (United States)

    Abreu, Angela A; Tavares, Fábio; Alves, Maria Madalena; Pereira, Maria Alcina

    2016-11-01

    Proof of principle of biohythane and potential energy production from garden waste (GW) is demonstrated in this study in a two-step process coupling dark fermentation and anaerobic digestion. The synergistic effect of using co-cultures of extreme thermophiles to intensify biohydrogen dark fermentation is demonstrated using xylose, cellobiose and GW. Co-culture of Caldicellulosiruptor saccharolyticus and Thermotoga maritima showed higher hydrogen production yields from xylose (2.7±0.1molmol(-1) total sugar) and cellobiose (4.8±0.3molmol(-1) total sugar) compared to individual cultures. Co-culture of extreme thermophiles C. saccharolyticus and Caldicellulosiruptor bescii increased synergistically the hydrogen production yield from GW (98.3±6.9Lkg(-1) (VS)) compared to individual cultures and co-culture of T. maritima and C. saccharolyticus. The biochemical methane potential of the fermentation end-products was 322±10Lkg(-1) (CODt). Biohythane, a biogas enriched with 15% hydrogen could be obtained from GW, yielding a potential energy generation of 22.2MJkg(-1) (VS). PMID:27484669

  11. Boosting dark fermentation with co-cultures of extreme thermophiles for biohythane production from garden waste.

    Science.gov (United States)

    Abreu, Angela A; Tavares, Fábio; Alves, Maria Madalena; Pereira, Maria Alcina

    2016-11-01

    Proof of principle of biohythane and potential energy production from garden waste (GW) is demonstrated in this study in a two-step process coupling dark fermentation and anaerobic digestion. The synergistic effect of using co-cultures of extreme thermophiles to intensify biohydrogen dark fermentation is demonstrated using xylose, cellobiose and GW. Co-culture of Caldicellulosiruptor saccharolyticus and Thermotoga maritima showed higher hydrogen production yields from xylose (2.7±0.1molmol(-1) total sugar) and cellobiose (4.8±0.3molmol(-1) total sugar) compared to individual cultures. Co-culture of extreme thermophiles C. saccharolyticus and Caldicellulosiruptor bescii increased synergistically the hydrogen production yield from GW (98.3±6.9Lkg(-1) (VS)) compared to individual cultures and co-culture of T. maritima and C. saccharolyticus. The biochemical methane potential of the fermentation end-products was 322±10Lkg(-1) (CODt). Biohythane, a biogas enriched with 15% hydrogen could be obtained from GW, yielding a potential energy generation of 22.2MJkg(-1) (VS).

  12. Potential for anaerobic conversion of xenobiotics

    DEFF Research Database (Denmark)

    Mogensen, Anders Skibsted; Dolfing, J.; Haagensen, Frank;

    2003-01-01

    This review covers the latest research on the anaerobic biodegradation of aromatic xenobiotic compounds, with emphasis on surfactants, polycyclic aromatic hydrocarbons, phthalate esters, polychlorinated biphenyls, halogenated phenols, and pesticides. The versatility of anaerobic reactor systems...... regarding the treatment of xenobiotics is shown with the focus on the UASB reactor, but the applicability of other reactor designs for treatment of hazardous waste is also included. Bioaugmentation has proved to be a viable technique to enhance a specific activity in anaerobic reactors and recent research...

  13. Uranium enrichment by gas centrifuge

    International Nuclear Information System (INIS)

    After recalling the physical principles and the techniques of centrifuge enrichment the report describes the centrifuge enrichment programmes of the various countries concerned and compares this technology with other enrichment technologies like gaseous diffusion, laser, aerodynamic devices and chemical processes. The centrifuge enrichment process is said to be able to replace with advantage the existing enrichment facilities in the short and medium term. Future prospects of the process are also described, like recycled uranium enrichment and economic improvements; research and development needs to achieve the economic prospects are also indicated. Finally the report takes note of the positive aspect of centrifuge enrichment as far as safeguards and nuclear safety are concerned. 27 figs, 113 refs

  14. Molecular ecology of anaerobic reactor systems

    DEFF Research Database (Denmark)

    Hofman-Bang, H. Jacob Peider; Zheng, D.; Westermann, Peter;

    2003-01-01

    Anaerobic reactor systems are essential for the treatment of solid and liquid wastes and constitute a core facility in many waste treatment plants. Although much is known about the basic metabolism in different types of anaerobic reactors, little is known about the microbes responsible...... to the abundance of each microbe in anaerobic reactor systems by rRNA probing. This chapter focuses on various molecular techniques employed and problems encountered when elucidating the microbial ecology of anaerobic reactor systems. Methods such as quantitative dot blot/fluorescence in-situ probing using various...

  15. Effects of sludge inoculum and organic feedstock on active microbial communities and methane yield during anaerobic digestion

    OpenAIRE

    Wilkins, David; Rao, Subramanya; Lu, Xiaoying; Lee, Patrick K. H.

    2015-01-01

    Anaerobic digestion (AD) is a widespread microbial technology used to treat organic waste and recover energy in the form of methane (“biogas”). While most AD systems have been designed to treat a single input, mixtures of digester sludge and solid organic waste are emerging as a means to improve efficiency and methane yield. We examined laboratory anaerobic cultures of AD sludge from two sources amended with food waste, xylose, and xylan at mesophilic temperatures, and with cellulose at meso-...

  16. Diverse anaerobic Cr(VI) tolerant bacteria from Cr(VI)-contaminated 100H site at Hanford

    Science.gov (United States)

    Chakraborty, R.; Phan, R.; Lam, S.; Leung, C.; Brodie, E. L.; Hazen, T. C.

    2007-12-01

    Hexavalent Chromium [Cr(VI)] is a widespread contaminant found in soil, sediment, and ground water. Cr(VI) is more soluble, toxic, carcinogenic, and mutagenic compared to its reduced form Cr(III). In order to stimulate microbially mediated reduction of Cr(VI), a poly-lactate compound HRC was injected into the chromium contaminated aquifers at site 100H at Hanford. Based on the results of the bacterial community composition using high-density DNA microarray analysis of 16S rRNA gene products, we recently investigated the diversity of the dominant anaerobic culturable microbial population present at this site and their role in Cr(VI) reduction. Positive enrichments set up at 30°C using specific defined anaerobic media resulted in the isolation of an iron reducing isolate strain HAF, a sulfate reducing isolate strain HBLS and a nitrate reducing isolate, strain HLN among several others. Preliminary 16S rDNA sequence analysis identifies strain HAF as Geobacter metallireducens, strain HLN as Pseudomonas stutzeri and strain HBLS as a member of Desulfovibrio species. Strain HAF isolated with acetate as the electron donor utilized propionate, glycerol and pyruvate as alternative carbon sources, and reduced metals like Mn(IV) and Cr(VI). Growth was optimal at 37°C, pH of 6.5 and 0% salinity. Strain HLN isolated with lactate as electron donor utilized acetate, glycerol and pyruvate as alternative carbon sources, and reduced metals like Mn(IV) and Cr(VI). Optimal growth was observed at 37°C, at a pH of 7.5 and 0.3% salinity. Anaerobic active washed cell suspension of strain HLN reduced almost 95 micromolar Cr(VI) within 4 hours relative to controls. Further, with 100 micromolar Cr(VI) as the sole electron acceptor, cells of strain HLN grew to cell numbers of 4.05X 107/ml over a period of 24hrs after an initial lag, demonstrating direct enzymatic Cr(VI) reduction by this species. 10mM lactate served as the sole electron donor. These results demonstrate that Cr

  17. 新型OxyPlateTM厌氧系统隔离眼部厌氧菌的评估%Evaluation of the new OxyPlateTM Anaerobic System for the isolation of ocular anaerobic bacteria

    Institute of Scientific and Technical Information of China (English)

    Emily K. Deschler; Paul P. Thompson; Regis Paul Kowalski

    2013-01-01

    目的:厌氧细菌可引起眼部感染,我们测试OxyPlateTM厌氧系统(OxyPlateTM Anaerobic System,OXY)隔离可引起眼部疾病的厌氧细菌.方法:OXY不需要直接的厌氧条件(比如厌氧袋,罐),将其与常规的厌氧袋培养基相比.琼脂培养基上眼部厌氧细菌菌株在好氧和厌氧条件下(厌氧袋)行标准的菌落计数:(1)OXY(好氧);(2)5%羊血(sheep blood,SB);(3)巧克力琼脂;(4)Schaedler琼脂.测试的眼部体外培养细菌来自眼内炎,泪囊炎,包括10个丙酸杆菌和3个放线菌种类.在每个培养条件下,每个细菌菌落计数隔离,排名从大到小,并在非参数比较下确定最佳的培养条件.结果:所有的厌氧条件对于厌氧菌株呈阳性反应.厌氧菌在有氧条件下的SB和Schaedler的琼脂中无法增长.痤疮丙酸杆菌在巧克力琼脂中生长稀疏.作为一种厌氧系统,在厌氧袋SB分离比OXY(P=0.0028)和巧克力琼脂(P=0.0028)分离出更多的菌落数.结论:虽然OXY经测试并没比其他的厌氧系统更高效,它似乎是一个合理隔离厌氧细菌的替代方法.其琼脂培养基在一个专门设计的盘并不需要厌氧袋使得OXY优于其他厌氧系统.%AIM: Anaerobic bacteria can cause ocular infections. We tested the OxyPlateTM Anaerobic System (OXY) to isolate pertinent anaerobic bacteria that can cause ocular disease.METHODS: OXY, which does not require direct anaerobic conditions (i.e. bags, jars), was compared to conventional isolation of incubating culture media in anaerobic bags. Standard colonies counts were performed on anaerobic ocular bacterial isolates under aerobic and anaerobic conditions (anaerobic bags) using agar media: 1) OXY (aerobic only), 2) 5% sheep blood (SB), 3) Chocolate, and 4) Schaedler. The bacteria tested were de-identified ocular isolates cultured from endophthalmitis and dacryocystitis that include 10 Propionibacterium acnes and 3 Actinomyces species. The colony counts for each bacteria isolate, on each

  18. Chain elongation in anaerobic reactor microbiomes to recover resources from waste

    NARCIS (Netherlands)

    Spirito, C.M.; Richter, H.; Rabaey, K.; Stams, A.J.M.; Angenent, L.T.

    2014-01-01

    Different microbial pathways can elongate the carbon chains of molecules in open cultures of microbial populations (i.e. reactor microbiomes) under anaerobic conditions. Here, we discuss three such pathways: 1. homoacetogenesis to combine two carbon dioxide molecules into acetate; 2. succinate forma

  19. Microbial community analysis of ambient temperature anaerobic digesters

    Energy Technology Data Exchange (ETDEWEB)

    Ciotola, R. [Ohio State Univ., Columbus, OH (United States). Dept. of Food, Agriculture and Biological Engineering

    2010-07-01

    This paper reported on a study in which designs for Chinese and Indian fixed-dome anaerobic digesters were modified in an effort to produce smaller and more affordable digesters. While these types of systems are common in tropical regions of developing countries, they have not been used in colder climates because of the low biogas yield during the winter months. Although there is evidence that sufficient biogas production can be maintained in colder temperatures through design and operational changes, there is a lack of knowledge about the seasonal changes in the composition of the microbial communities in ambient temperature digesters. More knowledge is needed to design and operate systems for maximum biogas yield in temperate climates. The purpose of this study was to cultivate a microbial community that maximizes biogas production at psychrophilic temperatures. The study was conducted on a 300 gallon experimental anaerobic digester on the campus of Ohio State University. Culture-independent methods were used on weekly samples collected from the digester in order to examine microbial community response to changes in ambient temperature. Microbial community profiles were established using universal bacterial and archaeal primers that targeted the 16S rRNA gene. In addition to the methanogenic archaea, this analysis also targeted some of the other numerically and functionally important microbial taxa in anaerobic digesters, such as hydrolytic, fermentative, acetogenic and sulfate reducing bacteria. According to preliminary results, the composition of the microbial community shifts with changes in seasonal temperature.

  20. Pulse shear stress for anaerobic membrane bioreactor fouling control.

    Science.gov (United States)

    Yang, Jixiang; Spanjers, Henri; van Lier, Jules B

    2011-01-01

    Increase of shear stress at membrane surfaces is a generally applied strategy to minimize membrane fouling. It has been reported that a two-phase flow, better known as slug flow, is an effective way to increase shear stress. Hence, slug flow was introduced into an anaerobic membrane bioreactor for membrane fouling control. Anaerobic suspended sludge was cultured in an anaerobic membrane bioreactor (AMBR) operated with a side stream inside-out tubular membrane unit applying sustainable flux flow regimes. The averaged particle diameter decreased from 20 to 5 microm during operation of the AMBR. However, the COD removal efficiency did not show any significant deterioration, whereas the specific methanogenic activity (SMA) increased from 0.16 to 0.41 gCOD/g VSS/day. Nevertheless, the imposed gas slug appeared to be insufficient for adequate fouling control, resulting in rapidly increasing trans membrane pressures (TMP) operating at a flux exceeding 16 L/m2/h. Addition of powdered activated carbon (PAC) enhanced the effect of slug flow on membrane fouling. However, the combined effect was still considered as not being significant. The tubular membrane was subsequently equipped with inert inserts for creating a locally increased shear stress for enhanced fouling control. Results show an increase in the membrane flux from 16 L/m2/h to 34 L/m2/h after the inserts were mounted in the membrane tube. PMID:22097007

  1. Anaerobic biodegradability of fish remains: experimental investigation and parameter estimation.

    Science.gov (United States)

    Donoso-Bravo, Andres; Bindels, Francoise; Gerin, Patrick A; Vande Wouwer, Alain

    2015-01-01

    The generation of organic waste associated with aquaculture fish processing has increased significantly in recent decades. The objective of this study is to evaluate the anaerobic biodegradability of several fish processing fractions, as well as water treatment sludge, for tilapia and sturgeon species cultured in recirculated aquaculture systems. After substrate characterization, the ultimate biodegradability and the hydrolytic rate were estimated by fitting a first-order kinetic model with the biogas production profiles. In general, the first-order model was able to reproduce the biogas profiles properly with a high correlation coefficient. In the case of tilapia, the skin/fin, viscera, head and flesh presented a high level of biodegradability, above 310 mLCH₄gCOD⁻¹, whereas the head and bones showed a low hydrolytic rate. For sturgeon, the results for all fractions were quite similar in terms of both parameters, although viscera presented the lowest values. Both the substrate characterization and the kinetic analysis of the anaerobic degradation may be used as design criteria for implementing anaerobic digestion in a recirculating aquaculture system. PMID:25812103

  2. Biomass stabilization in the anaerobic digestion of wastewater sludges

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, C. [Universidad de Sevilla, Dept. de Ingenieria Quimica y Ambiental, Sevilla (Spain); Gutierrez, J.C. [Universidad Pablo de Olavide, Dept. de Ciencias Ambientales, Sevilla (Spain); Lebrato, J. [Universidad de Sevilla, Grupo Tratamiento de Aguas Residuales, Sevilla (Spain)

    2005-07-01

    Sludge stabilization processes include both volatile solid destruction and biomass stabilization. Traditionally, both processes have been considered together, in such a way that, when volatile solid destruction is achieved, the biomass is considered stabilized. In this study, volatile solids reduction and biomass stabilization in the anaerobic digestion of primary, secondary and mixed sludges from municipal wastewater treatment plants were researched in batch cultures by measurements of suspended solids and suspended lipid-phosphate. The estimated kinetic constants were higher in all sludge types tested for the biomass stabilization process, indicating that volatile solids destruction and biomass stabilization are not parallel processes, since the latter one is reached before the former. (Author)

  3. Biomass stabilization in the anaerobic digestion of wastewater sludges

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, C. [Universidad de Sevilla (Spain). Escuela Universitaria Politecnica. Departamento de Ingenieria Quimica y Ambiental; Gutierrez, J.C. [Universidad Pablo de Olavide, Sevilla (Spain). Departamento de Ciencias Ambientales; Lebrato, J. [Universidad de Sevilla (Spain). Escuela Universitaria Politecnica

    2006-07-15

    Sludge stabilization processes include both volatile solid destruction and biomass stabilization. Traditionally, both processes have been considered together, in such a way that, when volatile solid destruction is achieved, the biomass is considered stabilized. In this study, volatile solids reduction and biomass stabilization in the anaerobic digestion of primary, secondary and mixed sludges from municipal wastewater treatment plants were researched in batch cultures by measurements of suspended solids and suspended lipid-phosphate. The estimated kinetic constants were higher in all sludge types tested for the biomass stabilization process, indicating that volatile solids destruction and biomass stabilization are not parallel processes, since the latter one is reached before the former. (author)

  4. Anaerobic digestion of coffee waste

    OpenAIRE

    L. Neves; Ribeiro, R.; Oliveira, Rosário; Alves, M. M.

    2005-01-01

    The anaerobic co-digestion of five different by-products from instant coffee substitutes production was studied in mesophilic conditions. The co-substrate was the excess of sewage sludge from the wastewater treatment plant located in the same coffee factory. Four of the tested wastes produced methane in the range of 0.24-0.28 m³CH4(STP)/kgVSinitial . Reduction of 50-73% in total solids and 75-80% in volatile solids were obtained and the hydrolysis rate constants were in the ran...

  5. Phylogenetic and Metabolic Diversity of Planctomycetes from Anaerobic, Sulfide- and Sulfur-Rich Zodletone Spring, Oklahoma▿

    OpenAIRE

    Elshahed, Mostafa S.; Youssef, Noha H.; Luo, Qingwei; Najar, Fares Z; Roe, Bruce A; Sisk, Tracy M.; Bühring, Solveig I.; Hinrichs, Kai-Uwe; Krumholz, Lee R

    2007-01-01

    We investigated the phylogenetic diversity and metabolic capabilities of members of the phylum Planctomycetes in the anaerobic, sulfide-saturated sediments of a mesophilic spring (Zodletone Spring) in southwestern Oklahoma. Culture-independent analyses of 16S rRNA gene sequences generated using Planctomycetes-biased primer pairs suggested that an extremely diverse community of Planctomycetes is present at the spring. Although sequences that are phylogenetically affiliated with cultured hetero...

  6. Anaerobic ammonium oxidation in a bioreactor treating slaughterhouse wastewater

    Directory of Open Access Journals (Sweden)

    V. Reginatto

    2005-12-01

    Full Text Available Ammonium oxidation was thought to be an exclusively aerobic process; however, as recently described in the literature, it is also possible under anaerobic conditions and this process was named ANAMMOX. This work describes the operation of a system consisting of a denitrifying reactor coupled to a nitrifying reactor used for removal of nitrogen from slaughterhouse wastewater. During operation of the denitrifying reactor an average nitrogen ammonium removal rate of 50 mg/Ld was observed. This biomass was used to seed a second reactor, operated in repeated fed batch mode, fed with synthetic medium specific to the growth of bacteria responsible for the ANAMMOX process. The nitrogen loading rate varied between 33 and 67 mgN/Ld and average nitrogen removal was 95% and 40%, respectively. Results of fluorescence in situ hybridization (FISH confirmed the presence of anammox-like microorganisms in the enriched biomass.

  7. Mining of hemicellulose and lignin degrading genes from differentially enriched methane producing microbial community.

    Science.gov (United States)

    Pandit, Prabhakar D; Gulhane, Madhuri K; Khardenavis, Anshuman A; Purohit, Hemant J

    2016-09-01

    Study creates a scenario for enrichment and selection of ligno-hemicellulose degrading genotypes with anaerobic bioreactor as a model using rice straw, vegetable waste and food waste as substrates. Relative discrimination analysis showed that the hydrolytic pathways and associated microbial communities for ligno-hemicellulose degradation were dominatingly colonized with rice straw as substrate. The dominating bacteria were Caldicellulosiruptor, Fervidobacterium, Cytophaga, Ruminococcus, Thermotoga associated with hemicellulose degradation and Burkholderia, Pandorea, Sphingomonas, Spirochaeta, Pseudomonas for lignocellulose hydrolysis. This was further supported by the abundance of anaerobic aromatic compound degrading genes along with genes for xylanase and xylosidase in rice straw enriched community. The metagenome analysis data was validated by evaluation of the biochemical methane potential for these substrates. Food waste being most amenable substrate yielded 1410mL of biogas/gVS added whereas, biogas yield of 1160mL/gVS and 1080mL/gVS was observed in presence of vegetable waste and rice straw respectively.

  8. Instrumentation in anaerobic treatment - research and practice

    NARCIS (Netherlands)

    Spanjers, H.; Lier, van J.B.

    2006-01-01

    High rate anaerobic treatment reactors are able to uncouple solids and liquid retention time, resulting in high biomass concentrations. Principal advantages of anaerobic treatment include: energy efficiency, low biomass yield, low nutrient requirement and high volumetric organic loadings. In order t

  9. Carbon monoxide conversion by anaerobic bioreactor sludges

    NARCIS (Netherlands)

    Sipma, J.; Stams, A.J.M.; Lens, P.N.L.; Lettinga, G.

    2003-01-01

    Seven different anaerobic sludges from wastewater treatment reactors were screened for their ability to convert carbon monoxide (CO) at 30 and 55degreesC
    Seven different anaerobic sludges from wastewater treatment reactors were screened for their ability to convert carbon monoxide (CO) at 30 and

  10. Anaerobic critical velocity in four swimming techniques.

    Science.gov (United States)

    Neiva, H P; Fernandes, R J; Vilas-Boas, J P

    2011-03-01

    The aim of this study was to assess critical velocity in order to control and evaluate anaerobic swimming training. 51 highly trained male swimmers performed maximal 15, 25, 37.5 and 50 m in the 4 swimming techniques to determine critical velocity from the distance-time relationship. Anaerobic critical velocity was compared with 100 m swimming performance and corresponding partials. Complementarily, 9 swimmers performed a 6×50 m (4 min interval) training series at front crawl individual anaerobic critical velocity, capillary blood lactate concentrations being assessed after each repetition. The mean±SD values of anaerobic critical velocity and its relationship with the 100 m event were: 1.61±0.07 (r=0.60, p=0.037), 1.53±0.05 (r=0.81, p=0.015), 1.33±0.05 (r=0.83, p=0.002), and 1.75±0.05 (r=0.74, p=0.001), for butterfly, backstroke, breaststroke and front crawl, respectively. However, differences between anaerobic critical velocity and performance were observed (with exception of the second half of the 100 m swimming events in breaststroke and butterfly). Lactate concentration values at the end of the series were 14.52±1.06 mmol.l (-1), which suggests that it was indeed an anaerobic training set. In this sense, anaerobic critical velocity can be used to prescribe anaerobic training intensities.

  11. 21 CFR 866.2120 - Anaerobic chamber.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anaerobic chamber. 866.2120 Section 866.2120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber....

  12. Isolation, growth, and metabolism of an obligately anaerobic, selenate- respiring bacterium, strain SES-3

    Science.gov (United States)

    Oremland, R.S.; Blum, J.S.; Culbertson, C.W.; Visscher, P.T.; Miller, L.G.; Dowdle, P.; Strohmaier, F.E.

    1994-01-01

    A gram-negative, strictly anaerobic, motile vibrio was isolated from a selenate-respiring enrichment culture. The isolate, designated strain SES-3, grew by coupling the oxidation of lactate to acetate plus CO2 with the concomitant reduction of selenate to selenite or of nitrate to ammonium. No growth was observed on sulfate or selenite, but cell suspensions readily reduced selenite to elemental selenium (Se0). Hence, SES-3 can carry out a complete reduction of selenate to Se0. Washed cell suspensions of selenate- grown cells did not reduce nitrate, and nitrate-grown cells did not reduce selenate, indicating that these reductions are achieved by separate inducible enzyme systems. However, both nitrate-grown and selenate-grown cells have a constitutive ability to reduce selenite or nitrite. The oxidation of [14C]lactate to 14CO2 coupled to the reduction of selenate or nitrate by cell suspensions was inhibited by CCCP (carbonyl cyanide m- chlorophenylhydrazone), cyanide, and azide. High concentrations of selenite (5 mM) were readily reduced to Se0 by selenate-grown cells, but selenite appeared to block the synthesis of pyruvate dehydrogenase. Tracer experiments with [75Se]selenite indicated that cell suspensions could achieve a rapid and quantitative reduction of selenite to Se0. This reduction was totally inhibited by sulfite, partially inhibited by selenate or nitrite, but unaffected by sulfate or nitrate. Cell suspensions could reduce thiosulfate, but not sulfite, to sulfide. These results suggest that reduction of selenite to Se0 may proceed, in part, by some of the components of a dissimilatory system for sulfur oxyanions.

  13. In vitro culture of previously uncultured oral bacterial phylotypes.

    Science.gov (United States)

    Thompson, Hayley; Rybalka, Alexandra; Moazzez, Rebecca; Dewhirst, Floyd E; Wade, William G

    2015-12-01

    Around a third of oral bacteria cannot be grown using conventional bacteriological culture media. Community profiling targeting 16S rRNA and shotgun metagenomics methods have proved valuable in revealing the complexity of the oral bacterial community. Studies investigating the role of oral bacteria in health and disease require phenotypic characterizations that are possible only with live cultures. The aim of this study was to develop novel culture media and use an in vitro biofilm model to culture previously uncultured oral bacteria. Subgingival plaque samples collected from subjects with periodontitis were cultured on complex mucin-containing agar plates supplemented with proteose peptone (PPA), beef extract (BEA), or Gelysate (GA) as well as on fastidious anaerobe agar plus 5% horse blood (FAA). In vitro biofilms inoculated with the subgingival plaque samples and proteose peptone broth (PPB) as the growth medium were established using the Calgary biofilm device. Specific PCR primers were designed and validated for the previously uncultivated oral taxa Bacteroidetes bacteria HOT 365 and HOT 281, Lachnospiraceae bacteria HOT 100 and HOT 500, and Clostridiales bacterium HOT 093. All agar media were able to support the growth of 10 reference strains of oral bacteria. One previously uncultivated phylotype, Actinomyces sp. HOT 525, was cultivated on FAA. Of 93 previously uncultivated phylotypes found in the inocula, 26 were detected in in vitro-cultivated biofilms. Lachnospiraceae bacterium HOT 500 was successfully cultured from biofilm material harvested from PPA plates in coculture with Parvimonas micra or Veillonella dispar/parvula after colony hybridization-directed enrichment. The establishment of in vitro biofilms from oral inocula enables the cultivation of previously uncultured oral bacteria and provides source material for isolation in coculture.

  14. A Contrastive Research on American-Chinese Cultural Identity from Perspective of Mass Culture

    Institute of Scientific and Technical Information of China (English)

    赵欣

    2012-01-01

    The appearance and development of "Super Girl" accompanies with the rise of mass culture and it reflects the main features of mass culture.Meanwhile western mass cultural product especially the American mass cultural product "American Idol" influenced Chinese mass culture and it has produced massive impact on the identity of national cultural and cultural independence in China.The thesis can help to deepen and make up for the deficiency of mass culture theories,to enrich the applicational experience and the...

  15. Prospects of Anaerobic Digestion Technology in China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As the world's largest developing country, China must face the problem of managing municipal solid waste, and the challenge of organic waste disposal is even more serious. Considering the characteristics of traditional waste disposal technologies and the subsequent secondary pollution, anaerobic digestion has various advantages such as reduction in the land needed for disposal and preservation of environmental quality. In light of the energy crisis, this paper focuses on the potential production of biogas from biowaste through anaerobic digestion processes, the problems incurred by the waste collection system, and the efficiency of the anaerobic digestion process. Use of biogas in a combined heat and power cogeneration system is also discussed. Finally, the advantages of anaerobic digestion technology for the Chinese market are summarized. The anaerobic digestion is suggested to be a promising treating technology for the organic wastes in China.

  16. Anaerobic biorefinery: Current status, challenges, and opportunities.

    Science.gov (United States)

    Sawatdeenarunat, Chayanon; Nguyen, Duc; Surendra, K C; Shrestha, Shilva; Rajendran, Karthik; Oechsner, Hans; Xie, Li; Khanal, Samir Kumar

    2016-09-01

    Anaerobic digestion (AD) has been in use for many decades. To date, it has been primarily aimed at treating organic wastes, mainly manures and wastewater sludge, and industrial wastewaters. However, with the current advancements, a more open mind is required to look beyond these somewhat restricted original applications of AD. Biorefineries are such concepts, where multiple products including chemicals, fuels, polymers etc. are produced from organic feedstocks. The anaerobic biorefinery concept is now gaining increased attention, utilizing AD as the final disposal step. This review aims at evaluating the potential significance of anaerobic biorefineries, including types of feedstocks, uses for the produced energy, as well as sustainable applications of the generated residual digestate. A comprehensive analysis of various types of anaerobic biorefineries has been developed, including both large-scale and household level applications. Finally, future directives are highlighted showing how anaerobic biorefinery concept could impact the bioeconomy in the near future. PMID:27005786

  17. Methanogenic degradation of lignin-derived monoaromatic compounds by microbial enrichments from rice paddy field soil

    OpenAIRE

    Souichiro Kato; Kanako Chino; Naofumi Kamimura; Eiji Masai; Isao Yumoto; Yoichi Kamagata

    2015-01-01

    Anaerobic degradation of lignin-derived aromatics is an important metabolism for carbon and nutrient cycles in soil environments. Although there are some studies on degradation of lignin-derived aromatics by nitrate- and sulfate-reducing bacteria, knowledge on their degradation under methanogenic conditions are quite limited. In this study, methanogenic microbial communities were enriched from rice paddy field soil with lignin-derived methoxylated monoaromatics (vanillate and syringate) and t...

  18. Microbial gene functions enriched in the Deepwater Horizon deep-sea oil plume

    OpenAIRE

    Lu, Zhenmei; Deng, Ye; Van Nostrand, Joy D.; He, Zhili; Voordeckers, James; Zhou, Aifen; Lee, Yong-Jin; Olivia U Mason; Dubinsky, Eric A.; Chavarria, Krystle L.; Lauren M Tom; Fortney, Julian L.; Lamendella, Regina; Jansson, Janet K.; D'haeseleer, Patrik

    2011-01-01

    The Deepwater Horizon oil spill in the Gulf of Mexico is the deepest and largest offshore spill in the United State history and its impacts on marine ecosystems are largely unknown. Here, we showed that the microbial community functional composition and structure were dramatically altered in a deep-sea oil plume resulting from the spill. A variety of metabolic genes involved in both aerobic and anaerobic hydrocarbon degradation were highly enriched in the plume compared with outside the plume...

  19. EVALUATION OF QUANTITATIVE BACTERIOLOGICAL CULTURE BEFORE AND AFTER SPERM WASHING

    Institute of Scientific and Technical Information of China (English)

    ZHUANGGuang-Lun; ZHANGXi-Wei; WUGuo-Hua

    1989-01-01

    The aim of this study is to determine whether sperm washing can remove microorganisms from human semen. 20 ejaculates were cultured for detecting the existenoe of any possible aerobic and anaerobic becteria. Samples collected were divided into two groups: spocial

  20. Anaerobic Psychrophiles from Alaska, Antarctica, and Patagonia: Implications to Possible Life on Mars and Europa

    Science.gov (United States)

    Hoover, Richard B.; Pikuta, Elena V.; Marsic, Damien; Ng, Joseph

    2002-01-01

    Microorganisms preserved within the permafrost, glaciers, and polar ice sheets of planet Earth provide analogs for microbial life forms that may be encountered in ice or permafrost of Mars, Europa, Callisto, Ganymede, asteroids, comets or other frozen worlds in the Cosmos. The psychrophilic and psychrotolerant microbes of the terrestrial cryosphere help establish the thermal and temporal limitations of life on Earth and provide clues to where and how we should search for evidence of life elsewhere in the Universe. For this reason, the cold-loving microorganisms are directly relevant to Astrobiology. Cryopreserved microorganisms can remain viable (in deep anabiosis) in permafrost and ice for millions of years. Permafrost, ice wedges, pingos, glaciers, and polar ice sheets may contain intact ancient DNA, lipids, enzymes, proteins, genes, and even frozen and yet viable ancient microbiota. Some microorganisms carry out metabolic processes in water films and brine, acidic, or alkaline channels in permafrost or ice at temperatures far below 0 C. Complex microbial communities live in snow, ice-bubbles, cryoconite holes on glaciers and ancient microbial ecosystems are cryopreserved within the permafrost, glaciers, and polar caps. In the Astrobiology group of the NASA Marshall Space Flight Center and the University of Alabama at Huntsville, we have employed advanced techniques for the isolation, culture, and phylogenetic analysis of many types of microbial extremophiles. We have also used the Environmental Scanning Electron Microscope to study the morphology, ultra-microstructure and chemical composition of microorganisms in ancient permafrost and ice. We discuss several interesting and novel anaerobic microorganisms that we have isolated and cultured from the Pleistocene ice of the Fox Tunnel of Alaska, guano of the Magellanic Penguin, deep-sea sediments from the vicinity of the Rainbow Hydrothermal Vent and enrichment cultures from ice of the Patriot Hills of Antarctica

  1. Bacteremia due to anaerobic bacteria: epidemiology in a northern Bari Hospital, Italy

    Directory of Open Access Journals (Sweden)

    Maria Antonietta Distasi

    2015-06-01

    Full Text Available Background. Anaerobic bacteria are part of the commensal bacterial flora of skin and mucosae. Iatrogenic and pathological conditions altering this commensal relationship cause life-threatening diseases. Materials and Methods. We analysed the blood cultures sent to the microbiology of our hospital between 2008 and the first quarter of 2013 to measure the frequency of bacteraemia caused by anaerobia. We examined 3138 vials of blood cultures for anaerobia, inoculated following in-house standard procedures. The colonies grown in absence of air were subjected to biochemical analysis. The MICs of metronidazole for 23 of the 26 organisms was tested. Results. Twelve bacteria of the Bacteroides genus were identified, 9 Propionibacterium acnes, 1 Peptosctreptococcus micros, 1 Lactobacillus acidophilus, 1 Clostridium perfringens, 1 Prevotella oralis, 1 Eubacterium lentum. Conclusions. The analysis of the results suggests that the incidence of cultures positive to anaerobia was constant across the years. We note that advanced age, altered mucocutaneous tropism, alterations to the oral and intestinal bacterial flora intensify the risk of anaerobial pathogenicity. The analysis of the metronidazole-determined MIC suggests that the intestinal anaerobic flora responds well to therapy and prophylaxis with Metronidazole, while the anaerobic bacteria residing on skin and other mucosae are resistant. It is however hard to determine the clinical impact of anaerobic bacteremiae and their effect on the outcome of the patient, due to the scarcity of available clinical data.

  2. Anaerobic Bacteremia: Impact of Inappropriate Therapy on Mortality

    Science.gov (United States)

    Lee, Yangsoon; Park, Yongjung; Kim, Myungsook; Choi, Jun Yong; Yong, Dongeun; Jeong, Seok Hoon

    2016-01-01

    Background Investigation on incidence and mortality of anaerobic bacteremia (AB) is clinically relevant in spite of its infrequent occurrence and not often explored, which report varies according to period and institutions. Therefore, it is necessary to analyze the incidence and risk factors related to mortality and assess clinical outcomes of AB in current aspect. Materials and Methods Characteristics of AB patients and anaerobic bacteria from blood culture at a university hospital in 2012 were reviewed retrospectively. The correlation between risk factors and 28-day patient mortality was analyzed. Results A total of 70 non-duplicated anaerobic bacteria were isolated from blood of 70 bacteremia patients in 2012. The history of cardiovascular disease as host's risk factor was statistically significant (P = 0.0344) in univariate and multivariate analysis. Although the inappropriate therapy was not statistically significant in univariate and multivariate analysis, the survival rate of bacteremia was significantly worse in patients who had inappropriate therapy compared with those underwent appropriate therapy (hazard ratio, 5.4; 95% confidence interval, 1.7–6.9; P = 0.004). The most frequently isolated organism was Bacteroides fragilis (32 isolates, 46%), followed by Bacteroides thetaiotaomicron (10, 14%), and non-perfringens Clostridium (7, 10%). Conclusion The incidence of AB in 2012 was 2.3% (number of AB patients per 100 positive blood culture patients) and the mortality rate in patients with clinically significant AB was 21.4%. In addition, AB was frequently noted in patients having malignancy and the survival rate of AB was significantly worse in patients who received inappropriate therapy compared with those underwent appropriate therapy. PMID:27433379

  3. Earthquake forecast enrichment scores

    Directory of Open Access Journals (Sweden)

    Christine Smyth

    2012-03-01

    Full Text Available The Collaboratory for the Study of Earthquake Predictability (CSEP is a global project aimed at testing earthquake forecast models in a fair environment. Various metrics are currently used to evaluate the submitted forecasts. However, the CSEP still lacks easily understandable metrics with which to rank the universal performance of the forecast models. In this research, we modify a well-known and respected metric from another statistical field, bioinformatics, to make it suitable for evaluating earthquake forecasts, such as those submitted to the CSEP initiative. The metric, originally called a gene-set enrichment score, is based on a Kolmogorov-Smirnov statistic. Our modified metric assesses if, over a certain time period, the forecast values at locations where earthquakes have occurred are significantly increased compared to the values for all locations where earthquakes did not occur. Permutation testing allows for a significance value to be placed upon the score. Unlike the metrics currently employed by the CSEP, the score places no assumption on the distribution of earthquake occurrence nor requires an arbitrary reference forecast. In this research, we apply the modified metric to simulated data and real forecast data to show it is a powerful and robust technique, capable of ranking competing earthquake forecasts.

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

    Science.gov (United States)

    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.

  5. Medium factors on anaerobic production of rhamnolipids by Pseudomonas aeruginosa SG and a simplifying medium for in situ microbial enhanced oil recovery applications.

    Science.gov (United States)

    Zhao, Feng; Zhou, Jidong; Han, Siqin; Ma, Fang; Zhang, Ying; Zhang, Jie

    2016-04-01

    Aerobic production of rhamnolipid by Pseudomonas aeruginosa was extensively studied. But effect of medium composition on anaerobic production of rhamnolipid by P. aeruginosa was unknown. A simplifying medium facilitating anaerobic production of rhamnolipid is urgently needed for in situ microbial enhanced oil recovery (MEOR). Medium factors affecting anaerobic production of rhamnolipid were investigated using P. aeruginosa SG (Genbank accession number KJ995745). Medium composition for anaerobic production of rhamnolipid by P. aeruginosa is different from that for aerobic production of rhamnolipid. Both hydrophobic substrate and organic nitrogen inhibited rhamnolipid production under anaerobic conditions. Glycerol and nitrate were the best carbon and nitrogen source. The commonly used N limitation under aerobic conditions was not conducive to rhamnolipid production under anaerobic conditions because the initial cell growth demanded enough nitrate for anaerobic respiration. But rhamnolipid was also fast accumulated under nitrogen starvation conditions. Sufficient phosphate was needed for anaerobic production of rhamnolipid. SO4(2-) and Mg(2+) are required for anaerobic production of rhamnolipid. Results will contribute to isolation bacteria strains which can anaerobically produce rhamnolipid and medium optimization for anaerobic production of rhamnolipid. Based on medium optimization by response surface methodology and ions composition of reservoir formation water, a simplifying medium containing 70.3 g/l glycerol, 5.25 g/l NaNO3, 5.49 g/l KH2PO4, 6.9 g/l K2HPO4·3H2O and 0.40 g/l MgSO4 was designed. Using the simplifying medium, 630 mg/l of rhamnolipid was produced by SG, and the anaerobic culture emulsified crude oil to EI24 = 82.5 %. The simplifying medium was promising for in situ MEOR applications. PMID:26925616

  6. The Cultural Heritage of Interculturalism

    Directory of Open Access Journals (Sweden)

    Martin Peterson

    2015-03-01

    Full Text Available The article traces the cultural heritage of inter-cultural contexts, which have had profound impact over long time. It takes its departure in antique and culturally complex environments in the eastern Mediterranean. One millennium later corresponding inter-cultural conditions are explored in the western part of the Mediterranean. Both cases demonstrated their wide and long lasting influences on posterity. The cultural heritage implied the deep effects of cross-fertilization and ensuing cultural enrichment as the conflation of several well-endowed cultures took place. A similar, more powerful outcome followed the Radical Enlightenment in Leiden around 1650s and in Vienna some centuries later.

  7. Effect of music on anaerobic exercise performance.

    Science.gov (United States)

    Atan, T

    2013-03-01

    For years, mostly the effects of music on cardiorespiratory exercise performance have been studied, but a few studies have examined the effect of music on anaerobic exercise. The purpose of this study was to assess the effect of listening to music and its rhythm on anaerobic exercise: on power output, heart rate and the concentration of blood lactate. 28 male subjects were required to visit the laboratory on 6 occasions, each separated by 48 hours. Firstly, each subject performed the Running-based Anaerobic Sprint Test (RAST) under 3 conditions on separate days: while listening to "slow rhythm music", "fast rhythm music" or "no music". 48 hours after the subjects completed RAST under 3 conditions, Wingate Anaerobic Power (WAN) tests were performed under 3 music conditions. The order of the 3 conditions (slow music, fast music and no music) was selected randomly to prevent an order effect. Results showed no significant differences between 3 conditions in anaerobic power assessments, heart rate or blood lactate (p > 0.05). On the basis of these results it can be said that music cannot improve anaerobic performance. The type of music had no impact on power outputs during RAST and WAN exercise. As a conclusion, listening to music and its rhythm cannot enhance anaerobic performance and cannot change the physiological response to supramaximal exercise. PMID:24744463

  8. Biogas production from brewery spent grain enhanced by bioaugmentation with hydrolytic anaerobic bacteria.

    Science.gov (United States)

    Čater, Maša; Fanedl, Lijana; Malovrh, Špela; Logar, Romana Marinšek

    2015-06-01

    Lignocellulosic substrates are widely available but not easily applied in biogas production due to their poor anaerobic degradation. The effect of bioaugmentation by anaerobic hydrolytic bacteria on biogas production was determined by the biochemical methane potential assay. Microbial biomass from full scale upflow anaerobic sludge blanket reactor treating brewery wastewater was a source of active microorganisms and brewery spent grain a model lignocellulosic substrate. Ruminococcus flavefaciens 007C, Pseudobutyrivibrio xylanivorans Mz5(T), Fibrobacter succinogenes S85 and Clostridium cellulovorans as pure and mixed cultures were used to enhance the lignocellulose degradation and elevate the biogas production. P. xylanivorans Mz5(T) was the most successful in elevating methane production (+17.8%), followed by the coculture of P. xylanivorans Mz5(T) and F. succinogenes S85 (+6.9%) and the coculture of C. cellulovorans and F. succinogenes S85 (+4.9%). Changes in microbial community structure were detected by fingerprinting techniques.

  9. Removal of anaerobic soluble microbial products in a biological activated carbon reactor.

    Science.gov (United States)

    Dong, Xiaojing; Zhou, Weili; He, Shengbing

    2013-09-01

    The soluble microbial products (SMP) in the biological treatment effluent are generally of great amount and are poorly biodegradable. Focusing on the biodegradation of anaerobic SMP, the biological activated carbon (BAC) was introduced into the anaerobic system. The experiments were conducted in two identical lab-scale up-flow anaerobic sludge blanket (UASB) reactors. The high strength organics were degraded in the first UASB reactor (UASB1) and the second UASB (UASB2, i.e., BAC) functioned as a polishing step to remove SMP produced in UASB1. The results showed that 90% of the SMP could be removed before granular activated carbon was saturated. After the saturation, the SMP removal decreased to 60% on the average. Analysis of granular activated carbon adsorption revealed that the main role of SMP removal in BAC reactor was biodegradation. A strain of SMP-degrading bacteria, which was found highly similar to Klebsiella sp., was isolated, enriched and inoculated back to the BAC reactor. When the influent chemical oxygen demand (COD) was 10,000 mg/L and the organic loading rate achieved 10 kg COD/(m3 x day), the effluent from the BAC reactor could meet the discharge standard without further treatment. Anaerobic BAC reactor inoculated with the isolated Klebsiella was proved to be an effective, cheap and easy technical treatment approach for the removal of SMP in the treatment of easily-degradable wastewater with COD lower than 10,000 mg/L. PMID:24520716

  10. Selective separation of anaerobic sludge by means of hydrocyclones; Selektive Abtrennung von Anaerobschlamm mit Hydrozyklonen

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, M.; Bohnet, M. [Technische Univ. Braunschweig (Germany). Inst. fuer Verfahrens- und Kerntechnik

    1999-07-01

    In anaerobic waste water cleaning, biomass concentration constitutes a central problem because of long generating times and low biomass sinking speeds. In order to decouple hydraulic retention time from biomass retention time, biomass must be fed back into the reactor. The fact that separation by means of common gravitational separators such as sedimentation tanks and baffle plate thickeners is unspecific results in the enrichment in the reactor of inorganic solids, whose presence is corollary to the anaerobic sludge process. Hence, industry has a great interest in separating anaerobic sludge into organic and inorganic constituents as a means of safeguarding high operating stability and degradation efficiency of anaerobic reactors. Hydrocyclones, permitting selective separation, are an obvious approach. (orig.) [German] Bei der anaeroben Abwasserreinigung ist die Biomassekonzentrierung aufgrund langer Generationszeiten und geringer Sinkgeschwindigkeiten der Biomasse ein zentrales Problem. Zur Entkopplung der hydraulischen Verweilzeit von der Verweilzeit der Biomasse ist eine Rueckfuehrung der Biomasse erforderlich. Da bisher eingesetzte Schwerkraftabscheider, wie Absetzbecken und Lamellenklaerer, unspezifisch trennen, kommt es zu einer Anreicherung anorganischer Feststoffe im Reaktor, die sich prozessbedingt im Anaerobschlamm befinden. So hat die Industrie ein grosses Interesse an einer Auftrennung des Anaerobschlamms in organische und anorganische Bestandteile, um eine hohe Betriebsstabilitaet und Abbauleistung der Anaerobreaktoren zu gewaehrleisten. Hierzu bieten sich Hydrozyklone an, weil mit ihnen eine selektive Trennung moeglich ist. (orig.)

  11. Hydrogen Isotope Fractionation As a Tool to Identify Aerobic and Anaerobic PAH Biodegradation.

    Science.gov (United States)

    Kümmel, Steffen; Starke, Robert; Chen, Gao; Musat, Florin; Richnow, Hans H; Vogt, Carsten

    2016-03-15

    Aerobic and anaerobic polycyclic aromatic hydrocarbon (PAH) biodegradation was characterized by compound specific stable isotope analysis (CSIA) of the carbon and hydrogen isotope effects of the enzymatic reactions initiating specific degradation pathways, using naphthalene and 2-methylnaphtalene as model compounds. Aerobic activation of naphthalene and 2-methylnaphthalene by Pseudomonas putida NCIB 9816 and Pseudomonas fluorescens ATCC 17483 containing naphthalene dioxygenases was associated with moderate carbon isotope fractionation (εC = -0.8 ± 0.1‰ to -1.6 ± 0.2‰). In contrast, anaerobic activation of naphthalene by a carboxylation-like mechanism by strain NaphS6 was linked to negligible carbon isotope fractionation (εC = -0.2 ± 0.2‰ to -0.4 ± 0.3‰). Notably, anaerobic activation of naphthalene by strain NaphS6 exhibited a normal hydrogen isotope fractionation (εH = -11 ± 2‰ to -47 ± 4‰), whereas an inverse hydrogen isotope fractionation was observed for the aerobic strains (εH = +15 ± 2‰ to +71 ± 6‰). Additionally, isotope fractionation of NaphS6 was determined in an overlaying hydrophobic carrier phase, resulting in more reliable enrichment factors compared to immobilizing the PAHs on the bottle walls without carrier phase. The observed differences especially in hydrogen fractionation might be used to differentiate between aerobic and anaerobic naphthalene and 2-methylnaphthalene biodegradation pathways at PAH-contaminated field sites. PMID:26855125

  12. Characterization of a halotolerant acetoclastic methanogen highly enriched from marine sediment and its application in removal of acetate.

    Science.gov (United States)

    Kita, Akihisa; Suehira, Kazuhito; Miura, Toyokazu; Okamura, Yoshiko; Aki, Tsunehiro; Matsumura, Yukihiko; Tajima, Takahisa; Nishio, Naomichi; Nakashimada, Yutaka

    2016-02-01

    A marine sediment collected from Hiroshima Bay was cultured in artificial seawater, containing 0.51 M NaCl and 60 mM acetate and was found to exhibit active methane production at 37°C. Following four successive serial dilutions of cultures in medium containing 0.51 M NaCl, 60 mM acetate, and antibiotics, the well-acclimated methanogen was found to exhibit growth over a range of NaCl concentration (between 0 M and 2.06 M). The specific growth rates of the highly enriched methanogen, termed strain HA, in the absence of NaCl and in the presence of 1.54 M NaCl were estimated to be 0.037 h(-1) and 0.027 h(-1), respectively. The pH and temperature for optimum growth were determined to be 7.0-8.8 and 37°C, respectively. Although cells that had morphology similar to Methanosaeta sp. became dominant in the culture, methane production was still detected in the medium containing 0.51 M NaCl and other substrates such as methanol, formate, and methylamine, indicating contamination with other methanogens. The phylogenetic tree based on 16S rRNA gene sequences revealed that the strain HA was closely related to Methanosaeta harundinacea 6Ac and 8Ac(T), with sequence similarity of 98% and 97%, respectively. The continuous removal of acetate with upflow anaerobic filter reactor for industrial use of strain HA determined a methane production rate of 70 mM/d under condition of 0.51 M NaCl and successful methane production even under 1.54 M NaCl. PMID:26126941

  13. Hydrogen-enriched fuels

    Energy Technology Data Exchange (ETDEWEB)

    Roser, R. [NRG Technologies, Inc., Reno, NV (United States)

    1998-08-01

    NRG Technologies, Inc. is attempting to develop hardware and infrastructure that will allow mixtures of hydrogen and conventional fuels to become viable alternatives to conventional fuels alone. This commercialization can be successful if the authors are able to achieve exhaust emission levels of less than 0.03 g/kw-hr NOx and CO; and 0.15 g/kw-hr NMHC at full engine power without the use of exhaust catalysts. The major barriers to achieving these goals are that the lean burn regimes required to meet exhaust emissions goals reduce engine output substantially and tend to exhibit higher-than-normal total hydrocarbon emissions. Also, hydrogen addition to conventional fuels increases fuel cost, and reduces both vehicle range and engine output power. Maintaining low emissions during transient driving cycles has not been demonstrated. A three year test plan has been developed to perform the investigations into the issues described above. During this initial year of funding research has progressed in the following areas: (a) a cost effective single-cylinder research platform was constructed; (b) exhaust gas speciation was performed to characterize the nature of hydrocarbon emissions from hydrogen-enriched natural gas fuels; (c) three H{sub 2}/CH{sub 4} fuel compositions were analyzed using spark timing and equivalence ratio sweeping procedures and finally; (d) a full size pick-up truck platform was converted to run on HCNG fuels. The testing performed in year one of the three year plan represents a baseline from which to assess options for overcoming the stated barriers to success.

  14. Importance of pre-enrichment media for isolation of Salmonella spp. from swine and poultry

    DEFF Research Database (Denmark)

    Hoorfar, Jeffrey; Baggesen, Dorte Lau

    1998-01-01

    of the BPW method with parallel pre-enrichment of the same sample in UB resulted in high sensitivity for swine (0.92) and poultry (0.95) samples. A 2-h pre-enrichment in the non-selective Revive, followed by overnight enrichment in selective broth, resulted in a low sensitivity, particularly for the neck......, it may be advantageous to use SEE rather than standard culturing. (C) 1998 Federation of European Microbiological Societies....

  15. Taurine reduction in anaerobic respiration of Bilophila wadsworthia RZATAU.

    OpenAIRE

    Laue, Heike; Denger, Karin; Cook, Alasdair M.

    1997-01-01

    Organosulfonates are important natural and man-made compounds, but until recently (T. J. Lie, T. Pitta, E. R. Leadbetter, W. Godchaux III, and J. R. Leadbetter. Arch. Microbiol. 166:204-210, 1996), they were not believed to be dissimilated under anoxic conditions. We also chose to test whether alkane- and arenesulfonates could serve as electron sinks in respiratory metabolism. We generated 60 anoxic enrichment cultures in mineral salts medium which included several potential electron donors a...

  16. Clinically significant anaerobic bacteria isolated from patients in a South African academic hospital: antimicrobial susceptibility testing.

    Science.gov (United States)

    Naidoo, S; Perovic, O; Richards, G A; Duse, A G

    2011-09-27

    BACKGROUND. Increasing resistance to some antimicrobial agents among anaerobic bacteria has made susceptibility patterns less predictable. METHOD. This was a prospective study of the susceptibility data of anaerobic organisms isolated from clinical specimens from patients with suspected anaerobic infections from June 2005 until February 2007. Specimens were submitted to the microbiology laboratory at Charlotte Maxeke Johannesburg Academic Hospital, where microscopy, culture and susceptibility testing were performed the using E test® strip minimum inhibitory concentration method. Results were interpreted with reference to Clinical and Laboratory Standards Institute guidelines for amoxicillin-clavulanate, clindamycin, metronidazole, penicillin, ertapenem, cefoxitin, ceftriaxone, chloramphenicol and piperacillin-tazobactam. RESULTS. One hundred and eighty anaerobic isolates were submitted from 165 patients. The most active antimicrobial agents were chloramphenicol (100% susceptible), ertapenem (97.2%), piperacillin-tazobactam (99.4%) and amoxicillin-clavulanic acid (96.7%). Less active were metronidazole (89.4%), cefoxitin (85%), clindamycin (81.7%), ceftriaxone (68.3%) and penicillin (33.3%). CONCLUSION. Susceptibility testing should be performed periodically to identify emerging trends in resistance and to modify empirical treatment of anaerobic infections.

  17. Microbial populations of an upflow anaerobic sludge blanket reactor treating wastewater from a gelatin industry.

    Science.gov (United States)

    Vieira, A M; Bergamasco, R; Gimenes, M L; Nakamura, C V; Dias Filho, B P

    2001-12-01

    The microbial populations of an upflow anaerobic sludge blanket reactor, used for treating wastewater from the gelatin industry, were studied by microbiological methods and phase-contrast and electron microscopy. Microscopy examination of the sludge showed a complex mixture of various rod-shaped and coccoid bacterial pluslong filaments and verymobile curved rods. In addition free-living anaerobic ciliates and flagellates were also observed. The trophic group population observed in decreasing order of dominance were hydrolytic and acetogenic at 10(6) and sulfate reducing and methanogenic at 10(5). The rate of methane production in anaerobic granular sludge cultivated in growth medium supplement with formate pressurized with H2:CO2 showed a significant increase in methane yield compared with theseed culture containingthe same substrate and atmosphere of N2:CO2. Similar rates of methane production were observed when the growth medium was supplemented with acetate pressurized either with H2:CO2 or N2:CO2. The number of total anaerobic bacteria at 10(7), fecal coliforms and total coliforms at 10(6), and fecal streptococci at 10(3) is based on colony counts on solid media. The four prevalent species of facultative anaerobic gram-negative bacteria that belong to the family of Enterobacteriaceae were identified as Escherichia coli, Esherichia fergusonii, Klebsiella oxytoca, and Citrobacter freundii. The species Aeromonas hydrophila, Aeromonas veronii, Acinetobacter iwoffi and Stenotrophomonas maltophila were the most frequently isolated glucose fermenting and nonfermenting gram-negative bacilli.

  18. Assessment of the ability of sludge to degrade PCP under anaerobic conditions

    Directory of Open Access Journals (Sweden)

    R. M. L. Bolaños

    2005-12-01

    Full Text Available The capacity of sludge from different sources to degrade pentachlorophenol (PCP was evaluated. Three 2.5 liter reactors (R1, R2, and R3 were inoculated with different anaerobic sludges, semi continuously fed and maintained in orbital motion at 30±1°C. R1 was inoculated with aerobic sludge and river sediment collected downstream from a pulp and paper plant. R2 received sludge from an anaerobic reactor treating effluents from a paper recycling plant and R3 received anaerobic sludge from a biodigestor treating industrial and domestic effluents. The sludges were first acclimatized to a culture medium generally recommended for organochloride anaerobic degradation studies. The reactors were then subjected to increasing concentrations of PCP from 0.05 to 10.0 mg.l-1. PCP degradation and metabolite formation were monitored using gas chromatography, and the effects of PCP on the anaerobic process were verified by monitoring pH, volatile fatty acids, alkalinity, total suspended solids, and chemical oxygen demand. It was found that PCP did not affect reactor performance. All the sludges displayed the best PCP degradation capacity at a concentration of 0.2 mg.l-1, producing fewer chlorinated metabolites than when higher PCP concentrations were applied. R1 consistently produced fewer chlorinated metabolites, confirming the hypothesis that pre exposure to chlorinated compounds improves the sludge's capacity to degrade PCP.

  19. Antimicrobial resistance and susceptibility testing of anaerobic bacteria.

    Science.gov (United States)

    Schuetz, Audrey N

    2014-09-01

    Infections due to anaerobic bacteria can be severe and life-threatening. Susceptibility testing of anaerobes is not frequently performed in laboratories, but such testing is important to direct appropriate therapy. Anaerobic resistance is increasing globally, and resistance trends vary by geographic region. An overview of a variety of susceptibility testing methods for anaerobes is provided, and the advantages and disadvantages of each method are reviewed. Specific clinical situations warranting anaerobic susceptibility testing are discussed.

  20. Characterizing the Anaerobic Response of Chlamydomonas reinhardtii by Quantitative Proteomics

    OpenAIRE

    Terashima, Mia; Specht, Michael; Naumann, Bianca; Hippler, Michael

    2010-01-01

    The versatile metabolism of the green alga Chlamydomonas reinhardtii is reflected in its complex response to anaerobic conditions. The anaerobic response is also remarkable in the context of renewable energy because C. reinhardtii is able to produce hydrogen under anaerobic conditions. To identify proteins involved during anaerobic acclimation as well as to localize proteins and pathways to the powerhouses of the cell, chloroplasts and mitochondria from C. reinhardtii in aerobic and anaerobic...

  1. High enrichment to low enrichment core's conversion. Technical securities

    International Nuclear Information System (INIS)

    This work presents the fulfillment of the technical securities subscribed by INVAP S.E. for the conversion of a high enriched uranium core. The reactor (of 5 thermal Mw), built in the 50's and 60's, is of the 'swimming pool' type, with light water and fuel elements of the curve plates MTR type, enriched at 93.15 %. These are neutronic and thermohydraulic securities. (Author)

  2. Interaction of perchlorate and trichloroethene bioreductions in mixed anaerobic culture.

    Science.gov (United States)

    Wen, Li-Lian; Yang, Qiang; Zhang, Zhao-Xin; Yi, Yang-Yi; Tang, Youneng; Zhao, He-Ping

    2016-11-15

    This work evaluated the interaction of perchlorate and trichloroethene (TCE), two common co-contaminants in groundwater, during bioreduction in serum bottles containing synthetic mineral salts media and microbial consortia. TCE at concentrations up to 0.3mM did not significantly affect perchlorate reduction; however, perchlorate concentrations higher than 0.1mM made the reduction of TCE significantly slower. Perchlorate primarily inhibited the reduction of vinyl chloride (VC, a daughter product of TCE) to ethene. Mechanistic analysis showed that the inhibition was mainly because perchlorate reduction is thermodynamically more favorable than reduction of TCE and its daughter products and not because of toxicity due to accumulation of dissolved oxygen produced during perchlorate reduction. As the initial perchlorate concentration increased from 0 to 600mg/L in a set of serum bottles, the relative abundance of Rhodocyclaceae (a putatively perchlorate-reducing genus) increased from 6.3 to 80.6%, while the relative abundance of Dehalococcoides, the only known genus that is able to reduce TCE all the way to ethene, significantly decreased. Similarly, the relative abundance of Proteobacteria (a phylum to which most known perchlorate-reducing bacteria belong) increased from 22% to almost 80%. PMID:27449607

  3. Concurrent nitrate and Fe(III) reduction during anaerobic biodegradation of phenols in a sandstone aquifer

    DEFF Research Database (Denmark)

    Broholm, Mette; Crouzet, C.; Arvin, Erik;

    2000-01-01

    The biodegradation of phenols (similar to 5, 60, 600 mg 1(-1)) under anaerobic conditions (nitrate enriched and unamended) was studied in laboratory microcosms with sandstone material and groundwater from within an anaerobic ammonium plume in an aquifer, The aqueous phase was sampled and analyzed...... for phenols and selected redox sensitive parameters on a regular basis. An experiment with sandstone material from specific depth intervals from a vertical profile across the ammonium plume was also conducted. The miniature microcosms used in this experiment were sacrificed for sampling for phenols...... and selected redox sensitive parameters at the end of the experiment. The sandstone material was characterized with respect to oxidation and reduction potential and Fe(II) and Fe(III) speciation prior to use for all microcosms and at the end of the experiments for selected microcosms. The redox conditions...

  4. Multivariate monitoring of anaerobic co-digestion

    DEFF Research Database (Denmark)

    Madsen, Michael; Holm-Nielsen, Jens Bo

    Anaerobic digestion processes for production of renewable energy in the form of biogas, and in the future hydrogen, are becoming increasingly important worldwide. Sustainable solutions for renewable energy production systems are given high political priority, amongst other things due to global...... warming and environmental concerns. Anaerobic digestion applied in agriculture can simultaneously convert heterogeneous biomasses and wastes from the primary agricultural sector and from the bio processing industries, for instance food processing, pharma, and biofuel production, into valuable organic...... distinct scales. The aim was to investigate, whether changes in the chemical environment in the anaerobic digesters could be monitored by NIRS enabling biogas plant operators to respond to the process dynamics. Results show that several key intermediates suitable for control of the anaerobic digestion...

  5. Exocellular electron transfer in anaerobic microbial communities

    NARCIS (Netherlands)

    Stams, A.J.M.; Bok, de F.A.M.; Plugge, C.M.; Eekert, van M.H.A.; Dolfing, J.; Schraa, G.

    2006-01-01

    Exocellular electron transfer plays an important role in anaerobic microbial communities that degrade organic matter. Interspecies hydrogen transfer between microorganisms is the driving force for complete biodegradation in methanogenic environments. Many organic compounds are degraded by obligatory

  6. An anaerobic mitochondrion that produces hydrogen

    NARCIS (Netherlands)

    Boxma, Brigitte; Graaf, Rob M. de; Staay, Georg W.M. van der; Alen, Theo A. van; Ricard, Guenola; Gabaldón, Toni; Hoek, Angela H.A.M. van; Moon-van der Staay, Seung Yeo; Koopman, Werner J.H.; Hellemond, Jaap J. van; Tielens, Aloysius G.M.; Friedrich, Thorsten; Veenhuis, Marten; Huynen, Martijn A.; Hackstein, Johannes H.P.

    2005-01-01

    Hydrogenosomes are organelles that produce ATP and hydrogen, and are found in various unrelated eukaryotes, such as anaerobic flagellates, chytridiomycete fungi and ciliates. Although all of these organelles generate hydrogen, the hydrogenosomes from these organisms are structurally and metabolicall

  7. Use of an Interculturally Enriched Collaboration Script in Computer-Supported Collaborative Learning in Higher Education

    NARCIS (Netherlands)

    Popov, V.; Biemans, H.J.A.; Kuznetsov, A.N.; Mulder, M.

    2014-01-01

    In this exploratory study, the authors introduced an interculturally enriched collaboration script (IECS) for working in culturally diverse groups within a computer-supported collaborative learning (CSCL) environment and then assessed student online collaborative behaviour, learning performance and

  8. Anammox enrichment from reject water on blank biofilm carriers and carriers containing nitrifying biomass: operation of two moving bed biofilm reactors (MBBR).

    Science.gov (United States)

    Zekker, Ivar; Rikmann, Ergo; Tenno, Toomas; Lemmiksoo, Vallo; Menert, Anne; Loorits, Liis; Vabamäe, Priit; Tomingas, Martin; Tenno, Taavo

    2012-07-01

    The anammox bacteria were enriched from reject water of anaerobic digestion of municipal wastewater sludge onto moving bed biofilm reactor (MBBR) system carriers-the ones initially containing no biomass (MBBR1) as well as the ones containing nitrifying biomass (MBBR2). Duration of start-up periods of the both reactors was similar (about 100 days), but stable total nitrogen (TN) removal efficiency occurred earlier in the system containing nitrifying biomass. Anammox TN removal efficiency of 70% was achieved by 180 days in both 20 l volume reactors at moderate temperature of 26.0°C. During the steady state phase of operation of MBBRs the average TN removal efficiencies and maximum TN removal rates in MBBR1 were 80% (1,000 g-N/m(3)/day, achieved by 308 days) and in MBBR2 85% (1,100 g-N/m(3)/day, achieved by 266 days). In both reactors mixed bacterial cultures were detected. Uncultured Planctomycetales bacterium clone P4, Candidatus Nitrospira defluvii and uncultured Nitrospira sp. clone 53 were identified by PCR-DGGE from the system initially containing blank biofilm carriers as well as from the nitrifying biofilm system; from the latter in addition to these also uncultured ammonium oxidizing bacterium clone W1 and Nitrospira sp. clone S1-62 were detected. FISH analysis revealed that anammox microorganisms were located in clusters in the biofilm. Using previously grown nitrifying biofilm matrix for anammox enrichment has some benefits over starting up the process from zero, such as less time for enrichment and protection against severe inhibitions in case of high substrate loading rates.

  9. Comparative Studies of Alternative Anaerobic Digestion Technologies

    OpenAIRE

    Inman, David C.

    2004-01-01

    Washington D.C. Water and Sewage Authority is planning to construct a new anaerobic digestion facility at its Blue Plains WWTP by 2008. The research conducted in this study is to aid the designers of this facility by evaluating alternative digestion technologies. Alternative anaerobic digestion technologies include thermophilic, acid/gas phased, and temperature phased digestion. In order to evaluate the relative merits of each, a year long study evaluated the performance of bench scale dig...

  10. Anaerobic Digestion of Paper Mill Wastewater

    OpenAIRE

    Shreeshivadasan Chelliapan; Siti Baizura Mahat; Md. Fadjil Md. Din; A. Yuzir; Othman, N.

    2012-01-01

    In general, paper mill wastewater contains complex organic substances which could not be treated completely using conventional treatment processes, e.g. aerobic processes. As a result, anaerobic technology is a promising alternative for paper mill wastewater treatment due to its ability to degrade hard organic compounds. In the present study, treatment of paper mill wastewater using a stage anaerobic reactor was investigated. The more specific objectives of this study were to confirm whether ...

  11. Psychrophilic anaerobic treatment of low strength wastewaters.

    OpenAIRE

    Rebac, S.

    1998-01-01

    The main objective of this thesis was to design a high-rate anaerobic system for the treatment low strength wastewaters under psychrophilic conditions.Psychrophilic (3 to 20 °C) anaerobic treatment of low strength synthetic and malting wastewater was investigated using a single and two stage expanded granular sludge bed (EGSB) reactor system. The chemical oxygen demand (COD) removal efficiencies found in the experiments with synthetic wastewater exceeded 90 % in the single stage reactor at im...

  12. EFFECT OF MUSIC ON ANAEROBIC EXERCISE PERFORMANCE

    OpenAIRE

    Atan, T.

    2013-01-01

    For years, mostly the effects of music on cardiorespiratory exercise performance have been studied, but a few studies have examined the effect of music on anaerobic exercise. The purpose of this study was to assess the effect of listening to music and its rhythm on anaerobic exercise: on power output, heart rate and the concentration of blood lactate. 28 male subjects were required to visit the laboratory on 6 occasions, each separated by 48 hours. Firstly, each subject performed the Running-...

  13. Characterization and Description of Anaeromyxobacter dehalogenans gen. nov., sp. nov., an Aryl-Halorespiring Facultative Anaerobic Myxobacterium

    OpenAIRE

    Sanford, Robert A.; Cole, James R.; Tiedje, James M

    2002-01-01

    Five strains were isolated which form a physiologically and phylogenetically coherent group of chlororespiring microorganisms and represent the first taxon in the Myxobacteria capable of anaerobic growth. The strains were enriched and isolated from various soils and sediments based on their ability to grow using acetate as an electron donor and 2-chlorophenol (2-CPh) as an electron acceptor. They are slender gram-negative rods with a bright red pigmentation that exhibit gliding motility and f...

  14. Methanethiol Removal from Biogas by Biological Conversion in an Anaerobic Biotrickling Filter

    Institute of Scientific and Technical Information of China (English)

    王佳佳; 张卫江; 徐姣

    2015-01-01

    In this study, methanethiol(MT)-degradation bacteria were cultivated by using MT, methanol and trimethylamine as carbon sources under anaerobic conditions. It was found that the batch bacteria used MT and metha-nol as carbon sources grew faster than those used trimethylamine. The enriched bacteria used MT and methanol as the carbon sources were respectively inoculated in different biotrickling filters. The biological conversion performance of MT under anaerobic conditions was investigated in biotrickling filters. The results showed that the performance of the biotrickling filter inoculated with the bacteria enriched using MT was better than that inoculated with the bacteria en-riched using methanol. When the inlet concentration of MT was 0.005vol%(50,ppm), the empty bed residence time was 50 s, pH value was 8.0, and the flow rate of the nutrient solution was 10 L/h, the removal efficiency of MT reached 95.3%. Adding methanol stimulated the growth of the biomass and the degradation of MT, but caused that some bacteria only degrading methanol outcompeted the bacteria only degrading MT. The concentration of sodium bicarbonate in the nutrient solution needed to be controlled lower than 30 g/L, otherwise, it would be harmful to the degradation of MT.

  15. 'Low-acid' sulfide oxidation using nitrate-enriched groundwater

    Science.gov (United States)

    Donn, Michael; Boxall, Naomi; Reid, Nathan; Meakin, Rebecca; Gray, David; Kaksonen, Anna; Robson, Thomas; Shiers, Denis

    2016-04-01

    where pH remains neutral. The "low-acid" oxidation of sulfides with nitrate as an electron acceptor has been demonstrated at the laboratory scale. In 90-day microcosm respirometry experiments, we exposed a mixture of pulverized quartz and pyrite -rich ore to natural, high-nitrate groundwater and inoculated the microcosms with a culture of aerobic and anaerobic nitrate-dependent iron and sulfur-oxidising microorganisms, which were enriched from ore, groundwater and activated waste water. Incubations were performed under both oxic and anoxic conditions, in addition to abiotic controls. Initial results show that oxidation of the sulfides under nitrate-rich and microbially enhanced conditions does produce less acid than the same material under oxic conditions, and to some degree can match the models as long as oxygen ingress can be controlled. These results are the focus of further research into how this process can be enhanced and whether it can be applied in the field. Nitrate-driven oxidation of sulfides could potentially be used as a new approach to reduce acid generation and leaching of contaminants from waste dumps, in a passive or actively managed process designed to deplete and/or ameliorate (i.e. through surface passivation) the mineralogical hazard. Developing our understanding of biological aspects of these processes may also allow testing of longer-term "bio-caps" for various tailings and dump materials.

  16. Support for an anaerobic sulfur cycle in two Canadian peatland soils

    Science.gov (United States)

    Blodau, Christian; Mayer, Bernhard; Peiffer, Stefan; Moore, Tim R.

    2007-06-01

    Sulfur cycling in peatlands may affect global CH4 emissions by suppression of methanogenesis through bacterial sulfate reduction (BSR). We sought evidence for anaerobic sulfur cycling in four peat mesocosms irrigated with sulfate at a loading of 0.8 and 3.3 g S m-2 yr-1. To this end we obtained concentration profiles of dissolved O2, C, S, and Fe, and determined 34S/32S ratios of sulfate, reduced inorganic sulfur (TRIS), and total sulfur. To estimate the importance of BSR for anaerobic respiration, peat was incubated with molybdate as inhibitor of BSR. In the mesocosms, pore water concentrations of dissolved sulfate and H2S adjusted to 5-20 μmol L-1 and 0-9 μmol L-1, respectively, whereas concentrations of CO2, CH4, and DOC reached millimolar levels. CO2 production was not explained by methanogenesis and net reduction of inorganic electron acceptors. In the shallow peat, H2S was produced and 34S in sulfate enriched by 3.6 to 6‰, indicating occurrence of BSR. Sulfate reducers also accounted for much of the metabolic activity. Addition of molybdate suppressed CO2 production by 20 to 50%. Deeper into the peat, the sulfate pool was apparently replenished from the peat matrix as sulfate became enriched in 32S, likely stemming from TRIS or organic sulfur in the peat. Sulfur was thus anaerobically cycled between oxidized and reduced pools. An electron acceptor capable of driving this cycle could not be conclusively identified. Regardless of this uncertainty, the results suggest that anaerobic S cycling can maintain BSR and potentially contribute to low methane production in soils of ombrotrophic bogs.

  17. SLEEP DEPRIVATION INDUCED ANXIETY AND ANAEROBIC PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Selma Arzu Vardar

    2007-12-01

    Full Text Available The aim of this study was to investigate the effects of sleep deprivation induced anxiety on anaerobic performance. Thirteen volunteer male physical education students completed the Turkish version of State Anxiety Inventory and performed Wingate anaerobic test for three times: (1 following a full-night of habitual sleep (baseline measurements, (2 following 30 hours of sleep deprivation, and (3 following partial-night sleep deprivation. Baseline measurements were performed the day before total sleep deprivation. Measurements following partial sleep deprivation were made 2 weeks later than total sleep deprivation measurements. State anxiety was measured prior to each Wingate test. The mean state anxiety following total sleep deprivation was higher than the baseline measurement (44.9 ± 12.9 vs. 27.6 ± 4.2, respectively, p = 0.02 whereas anaerobic performance parameters remained unchanged. Neither anaerobic parameters nor state anxiety levels were affected by one night partial sleep deprivation. Our results suggest that 30 hours continuous wakefulness may increase anxiety level without impairing anaerobic performance, whereas one night of partial sleep deprivation was ineffective on both state anxiety and anaerobic performance

  18. Anaerobic denitrification in fungi from the coastal marine sediments off Goa, India.

    Science.gov (United States)

    Cathrine, Sumathi J; Raghukumar, Chandralata

    2009-01-01

    Denitrification is a microbial process during which nitrate or nitrite is reduced under anaerobic condition to gaseous nitrogen. The Arabian Sea contains one of the major pelagic denitrification zones and in addition to this, denitrification also takes places along the continental shelf. Prokaryotic microorganisms were considered to be the only players in this process. However recent studies have shown that higher microeukaryotes such as fungi can also adapt to anaerobic mode of respiration and reduce nitrate to harmful green house gases such as NO and N2O. In this study we examined the distribution and biomass of fungi in the sediments of the seasonal anoxic region off Goa from two stations. The sampling was carried out in five different periods from October 2005, when dissolved oxygen levels were near zero in bottom waters to March 2006. We isolated mycelial fungi, thraustochytrids and yeasts. Species of Aspergillus and thraustochytrids were dominant. Fungi were isolated under aerobic, as well as anaerobic conditions from different seasons. Four isolates were examined for their denitrification activity. Two cultures obtained from the anoxic sediments showed better growth under anaerobic condition than the other two cultures that were isolated from oxic sediments. Our preliminary results suggest that several species of fungi can grow under oxygen deficient conditions and participate in denitrification processes. PMID:18834939

  19. Meadow enriched ACP process algebras

    OpenAIRE

    J.A. Bergstra; Middelburg, C.A.

    2009-01-01

    We introduce the notion of an ACP process algebra. The models of the axiom system ACP are the origin of this notion. ACP process algebras have to do with processes in which no data are involved. We also introduce the notion of a meadow enriched ACP process algebra, which is a simple generalization of the notion of an ACP process algebra to processes in which data are involved. In meadow enriched ACP process algebras, the mathematical structure for data is a meadow.

  20. Candidatus Desulfofervidus auxilii, a hydrogenotrophic sulfate-reducing bacterium involved in the thermophilic anaerobic oxidation of methane.

    Science.gov (United States)

    Krukenberg, Viola; Harding, Katie; Richter, Michael; Glöckner, Frank Oliver; Gruber-Vodicka, Harald R; Adam, Birgit; Berg, Jasmine S; Knittel, Katrin; Tegetmeyer, Halina E; Boetius, Antje; Wegener, Gunter

    2016-09-01

    The anaerobic oxidation of methane (AOM) is mediated by consortia of anaerobic methane-oxidizing archaea (ANME) and their specific partner bacteria. In thermophilic AOM consortia enriched from Guaymas Basin, members of the ANME-1 clade are associated with bacteria of the HotSeep-1 cluster, which likely perform direct electron exchange via nanowires. The partner bacterium was enriched with hydrogen as sole electron donor and sulfate as electron acceptor. Based on phylogenetic, genomic and metabolic characteristics we propose to name this chemolithoautotrophic sulfate reducer Candidatus Desulfofervidus auxilii. Ca. D. auxilii grows on hydrogen at temperatures between 50°C and 70°C with an activity optimum at 60°C and doubling time of 4-6 days. Its genome draft encodes for canonical sulfate reduction, periplasmic and soluble hydrogenases and autotrophic carbon fixation via the reductive tricarboxylic acid cycle. The presence of genes for pili formation and cytochromes, and their similarity to genes of Geobacter spp., indicate a potential for syntrophic growth via direct interspecies electron transfer when the organism grows in consortia with ANME. This first ANME-free enrichment of an AOM partner bacterium and its characterization opens the perspective for a deeper understanding of syntrophy in anaerobic methane oxidation. PMID:26971539

  1. Biohydrogen production from rotten orange with immobilized mixed culture: Effect of immobilization media for various composition of substrates

    International Nuclear Information System (INIS)

    Enriched–immobilized mixed culture was utilized to produce biohydrogen in mesophilic condition under anaerobic condition using rotten orange as substrate. The process was conducted in batch reactors for 100 hours. Microbial cultures from three different sources were subject to a series of enrichment and immobilized in two different types of media, i.e. calcium alginate (CA, 2%) and mixture of alginate and activated carbon (CAC, 1:1). The performance of immobilized culture in each media was tested for biohydrogen production using four different substrate compositions, namely orange meat (OM), orange meat added with peel (OMP), orange meat added with limonene (OML), and mixture of orange meat and peel added with limonene (OMPL). The results show that, with immobilized culture in CA, the variation of substrate composition gave significant effect on the production of biohydrogen. The highest production of biohydrogen was detected for substrate containing only orange meet, i.e. 2.5%, which was about 3-5 times higher than biohydrogen production from other compositions of substrate. The use of immobilized culture in CAC in general has increased the hydrogen production by 2-7 times depending on the composition of substrate, i.e. 5.4%, 4.8%, 5.1%, and 4.4% for OM, OMP, OML, and OMPL, respectively. The addition of activated carbon has eliminated the effect of inhibitory compounds in the substrate. The major soluble metabolites were acetic acid, propionic acid, and butyric acid

  2. Biohydrogen production from rotten orange with immobilized mixed culture: Effect of immobilization media for various composition of substrates

    Energy Technology Data Exchange (ETDEWEB)

    Damayanti, Astrilia, E-mail: liasholehasd@gmail.com [Department of Chemical Engineering, Faculty of Engineering, Semarang State University, E1 Building, 2nd floor, Kampus Sekaran, Gunungpati, Semarang 50229 (Indonesia); Department of Chemical Engineering, Faculty of Engineering, Gadjah Mada University, Jl. Grafika No. 2, Kampus UGM, Yogyakarta 55281 (Indonesia); Sarto,; Syamsiah, Siti; Sediawan, Wahyudi B. [Department of Chemical Engineering, Faculty of Engineering, Gadjah Mada University, Jl. Grafika No. 2, Kampus UGM, Yogyakarta 55281 (Indonesia)

    2015-12-29

    Enriched–immobilized mixed culture was utilized to produce biohydrogen in mesophilic condition under anaerobic condition using rotten orange as substrate. The process was conducted in batch reactors for 100 hours. Microbial cultures from three different sources were subject to a series of enrichment and immobilized in two different types of media, i.e. calcium alginate (CA, 2%) and mixture of alginate and activated carbon (CAC, 1:1). The performance of immobilized culture in each media was tested for biohydrogen production using four different substrate compositions, namely orange meat (OM), orange meat added with peel (OMP), orange meat added with limonene (OML), and mixture of orange meat and peel added with limonene (OMPL). The results show that, with immobilized culture in CA, the variation of substrate composition gave significant effect on the production of biohydrogen. The highest production of biohydrogen was detected for substrate containing only orange meet, i.e. 2.5%, which was about 3-5 times higher than biohydrogen production from other compositions of substrate. The use of immobilized culture in CAC in general has increased the hydrogen production by 2-7 times depending on the composition of substrate, i.e. 5.4%, 4.8%, 5.1%, and 4.4% for OM, OMP, OML, and OMPL, respectively. The addition of activated carbon has eliminated the effect of inhibitory compounds in the substrate. The major soluble metabolites were acetic acid, propionic acid, and butyric acid.

  3. Anaerobic digestion of cellulosic wastes

    International Nuclear Information System (INIS)

    Anaerobic digestion is a potentially attractive technology for volume reduction of cellulosic wastes. A substantial fraction of the waste is converted to off-gas and a relatively small volume of biologically stabilized sludge is produced. Process development work is underway using a 75-L digester to verify rates and conversions obtained at the bench scale, to develop start-up and operating procedures, and to generate effluent for characterization and disposal studies. Three runs using batch and batch-fed conditions have been made lasting 36, 90, and over 200 days. Solids solubilization and gas production rates and total solids destruction have met or exceeded the target values of 0.6 g cellulose per L of reactor per day, 0.5 L off-gas per L of reactor per day, and 80% destruction of solids, respectively. Successful start-up procedures have been developed, and preliminary effluent characterization and disposal studies have been done. A simple dynamic process model has been constructed to aid in further process development and for use in process monitoring and control of a large-scale digester. 7 references, 5 figures, 1 table

  4. Anaerobic digestion of cellulosic wastes

    International Nuclear Information System (INIS)

    Anaerobic digestion is a potentially attractive technology for volume reduction of low-level radioactive cellulosic wastes. A substantial fraction of the waste is converted to off-gas and a relatively small volume of biologically stabilized sludge is produced. Process development work has been completed using a 75-L digester to verify rates and conversions obtained at the bench scale. Start-up and operating procedures have been developed, and effluent was generated for characterization and disposal studies. Three runs using batch and fed-batch conditions were made lasting 36, 90, and 423 d. Solids solubilization rates and gas production rates averaged approximately 1.8 g cellulose per L of reactor per d and 1.2 L of off-gas per L reactor per d. Greater than 80% destruction of the volatile suspended solids was obtained. A simple dynamic process model was constructed to aid in process design and for use in process monitoring and control of a large-scale digester

  5. Building a Culture of Achievement

    Science.gov (United States)

    Major, Marc R.

    2009-01-01

    Culture is the social and intergenerational glue that defines, connects, sustains, and enriches the members of successful communities--including schools and classrooms. A classroom culture is a psychological atmosphere that nurtures and shapes students' attitudes about their own identity, classes, school, and learning in general. Classroom culture…

  6. Anaerobic Microbial Degradation of Hydrocarbons: From Enzymatic Reactions to the Environment.

    Science.gov (United States)

    Rabus, Ralf; Boll, Matthias; Heider, Johann; Meckenstock, Rainer U; Buckel, Wolfgang; Einsle, Oliver; Ermler, Ulrich; Golding, Bernard T; Gunsalus, Robert P; Kroneck, Peter M H; Krüger, Martin; Lueders, Tillmann; Martins, Berta M; Musat, Florin; Richnow, Hans H; Schink, Bernhard; Seifert, Jana; Szaleniec, Maciej; Treude, Tina; Ullmann, G Matthias; Vogt, Carsten; von Bergen, Martin; Wilkes, Heinz

    2016-01-01

    Hydrocarbons are abundant in anoxic environments and pose biochemical challenges to their anaerobic degradation by microorganisms. Within the framework of the Priority Program 1319, investigations funded by the Deutsche Forschungsgemeinschaft on the anaerobic microbial degradation of hydrocarbons ranged from isolation and enrichment of hitherto unknown hydrocarbon-degrading anaerobic microorganisms, discovery of novel reactions, detailed studies of enzyme mechanisms and structures to process-oriented in situ studies. Selected highlights from this program are collected in this synopsis, with more detailed information provided by theme-focused reviews of the special topic issue on 'Anaerobic biodegradation of hydrocarbons' [this issue, pp. 1-244]. The interdisciplinary character of the program, involving microbiologists, biochemists, organic chemists and environmental scientists, is best exemplified by the studies on alkyl-/arylalkylsuccinate synthases. Here, research topics ranged from in-depth mechanistic studies of archetypical toluene-activating benzylsuccinate synthase, substrate-specific phylogenetic clustering of alkyl-/arylalkylsuccinate synthases (toluene plus xylenes, p-cymene, p-cresol, 2-methylnaphthalene, n-alkanes), stereochemical and co-metabolic insights into n-alkane-activating (methylalkyl)succinate synthases to the discovery of bacterial groups previously unknown to possess alkyl-/arylalkylsuccinate synthases by means of functional gene markers and in situ field studies enabled by state-of-the-art stable isotope probing and fractionation approaches. Other topics are Mo-cofactor-dependent dehydrogenases performing O2-independent hydroxylation of hydrocarbons and alkyl side chains (ethylbenzene, p-cymene, cholesterol, n-hexadecane), degradation of p-alkylated benzoates and toluenes, glycyl radical-bearing 4-hydroxyphenylacetate decarboxylase, novel types of carboxylation reactions (for acetophenone, acetone, and potentially also benzene and

  7. Anaerobic Microbial Degradation of Hydrocarbons: From Enzymatic Reactions to the Environment.

    Science.gov (United States)

    Rabus, Ralf; Boll, Matthias; Heider, Johann; Meckenstock, Rainer U; Buckel, Wolfgang; Einsle, Oliver; Ermler, Ulrich; Golding, Bernard T; Gunsalus, Robert P; Kroneck, Peter M H; Krüger, Martin; Lueders, Tillmann; Martins, Berta M; Musat, Florin; Richnow, Hans H; Schink, Bernhard; Seifert, Jana; Szaleniec, Maciej; Treude, Tina; Ullmann, G Matthias; Vogt, Carsten; von Bergen, Martin; Wilkes, Heinz

    2016-01-01

    Hydrocarbons are abundant in anoxic environments and pose biochemical challenges to their anaerobic degradation by microorganisms. Within the framework of the Priority Program 1319, investigations funded by the Deutsche Forschungsgemeinschaft on the anaerobic microbial degradation of hydrocarbons ranged from isolation and enrichment of hitherto unknown hydrocarbon-degrading anaerobic microorganisms, discovery of novel reactions, detailed studies of enzyme mechanisms and structures to process-oriented in situ studies. Selected highlights from this program are collected in this synopsis, with more detailed information provided by theme-focused reviews of the special topic issue on 'Anaerobic biodegradation of hydrocarbons' [this issue, pp. 1-244]. The interdisciplinary character of the program, involving microbiologists, biochemists, organic chemists and environmental scientists, is best exemplified by the studies on alkyl-/arylalkylsuccinate synthases. Here, research topics ranged from in-depth mechanistic studies of archetypical toluene-activating benzylsuccinate synthase, substrate-specific phylogenetic clustering of alkyl-/arylalkylsuccinate synthases (toluene plus xylenes, p-cymene, p-cresol, 2-methylnaphthalene, n-alkanes), stereochemical and co-metabolic insights into n-alkane-activating (methylalkyl)succinate synthases to the discovery of bacterial groups previously unknown to possess alkyl-/arylalkylsuccinate synthases by means of functional gene markers and in situ field studies enabled by state-of-the-art stable isotope probing and fractionation approaches. Other topics are Mo-cofactor-dependent dehydrogenases performing O2-independent hydroxylation of hydrocarbons and alkyl side chains (ethylbenzene, p-cymene, cholesterol, n-hexadecane), degradation of p-alkylated benzoates and toluenes, glycyl radical-bearing 4-hydroxyphenylacetate decarboxylase, novel types of carboxylation reactions (for acetophenone, acetone, and potentially also benzene and

  8. Application of dynamic membranes in anaerobic membranes in anaerobic membrane bioreactor systems

    NARCIS (Netherlands)

    Erşahin, M.E.

    2015-01-01

    Anaerobic membrane bioreactors (AnMBRs) physically ensure biomass retention by the application of a membrane filtration process. With growing application experiences from aerobic membrane bioreactors (MBRs), the combination of membrane and anaerobic processes has received much attention and become m

  9. Anaerobic digestion of waste sludges from the alginate extraction process

    Energy Technology Data Exchange (ETDEWEB)

    Kerner, K.N.; Hanssen, J.F.; Pedersen, T.A. (Agricultural Univ. of Norway, Aas (NO). Dept. of Biological Sciences)

    1991-01-01

    Anaerobic digestion of waste sludges produced during the industrial extraction of alginate from the algal species Laminaria hyperborea (Gunn.) Foslie and Ascophyllum nodosum (L.) Le Jol was studied. Experiments were carried out in bench scale (8-litre) intermittently stirred digesters at 35{sup o}C. Sieve and flotation sludges were digested in batch (1 month) and semi-continuous cultures. In the semi-continuous trials, retention times of 23 days and 16 days were tested. Methane production varied from 0.10 to 0.15 litre g{sup -1} volatile solids (VS) added during batch; and from 0.07 to 0.28 litre g{sup -1} VS added during semi-continuous fermentation. Specific gas production was significantly higher at 23 days than at 16 days retention time. VS reductions were 20-40% (batch) and 40-50% (semi-continuous). A distinct improvement of the settling qualities of digester effluents was obtained during the anaerobic digestion process. (author).

  10. Growth and Population Dynamics of Anaerobic Methane-Oxidizing Archaea and Sulfate-Reducing Bacteria in a Continuous-Flow Bioreactor

    OpenAIRE

    Peter R. Girguis; Cozen, Aaron E.; DeLong, Edward F

    2005-01-01

    The consumption of methane in anoxic marine sediments is a biogeochemical phenomenon mediated by two archaeal groups (ANME-1 and ANME-2) that exist syntrophically with sulfate-reducing bacteria. These anaerobic methanotrophs have yet to be recovered in pure culture, and key aspects of their ecology and physiology remain poorly understood. To characterize the growth and physiology of these anaerobic methanotrophs and the syntrophic sulfate-reducing bacteria, we incubated marine sediments using...

  11. The effect of outside conditions on anaerobic ammonia oxidation reaction

    Institute of Scientific and Technical Information of China (English)

    YANG Min; WANG Shu-bo

    2016-01-01

    Organic carbon, inorganic carbon, temperature, pH and ORP are all to have a certain influence on the anaerobic ammonia oxidation reaction. We can draw some conclusions on the optimum conditions of anaerobic ammonia oxidation reaction. The optimum temperature of the anaerobic ammonia oxidation reaction is 30-35℃. And the optimum pH of the anaerobic ammonia reaction is 7.5-8.3. The presence of organic matters can affect the anaerobic ammonia reaction, and different organic matters have different influence on it. The concentration of the inorganic carbon also exist great influence on the reaction. High inorganic carbon concentration also can inhibit anaerobic ammonia oxidation reaction.

  12. Genome sequence of Victivallis vadensis ATCC BAA-548, an anaerobic bacterium from the phylum Lentisphaerae, isolated from the human gastro-intestinal tract

    Energy Technology Data Exchange (ETDEWEB)

    Van Passel, Mark W.J. [Wageningen University and Research Centre, The Netherlands; Kant, Ravi [University of Helsinki; Palva, Airi [University of Helsinki; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Dalin, Eileen [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Bruce, David [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Davenport, Karen W. [Los Alamos National Laboratory (LANL); Sims, David [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Han, Cliff [Los Alamos National Laboratory (LANL); Larimer, Frank W [ORNL; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Ovchinnikova, Galina [U.S. Department of Energy, Joint Genome Institute; Richardson, Paul [U.S. Department of Energy, Joint Genome Institute; De Vos, Willem M. [Wageningen University and Research Centre, The Netherlands; Smidt, Hauke [Wageningen University and Research Centre, The Netherlands; Zoetendal, Erwin G. [Wageningen University and Research Centre, The Netherlands

    2011-01-01

    Victivallis vadensis ATCC BAA-548 represents the first cultured representative from the novel phylum Lentisphaerae, a deep-branching bacterial lineage. Few cultured bacteria from this phylum are known, and V. vadensis therefore represents an important organism for evolutionary studies. V. vadensis is a strictly anaerobic sugar-fermenting isolate from the human gastro-intestinal tract.

  13. Influence Of Quinolone Lethality on Irradiated Anaerobic Growth of Escherichia Coli

    International Nuclear Information System (INIS)

    Bacteriostatic and bactericidal activities were measured with wild type cells and isomerase mutants of Escherichia coli for ciprofloxacin, formation of quinolone-gyrase-DNA complexes, observed as a sodium dodecyl sulfate (SDS) dependent drop in cell lysate viscosity, occurred during aerobic and anaerobic growth and in the presence and in the absence of chloramphenicol. Quinolone activity against Escherichia coli was examined during aerobic growth, aerobic treatment with chloramphenicol, and anaerobic growth. Nalidixic acid, norfloxacin and ciprofloxacin were lethal for cultures growing aerobically, and the bacteriostatic activity of each quinolone was unaffected by anaerobic growth. However, lethal activity was distinct for each quinolone with cells treated aerobically with chloramphenicol or grown anaerobically. Nalidixic acid failed to kill cells under both conditions, norfloxacin killed cells when they were grown anaerobically but not when they were treated with chloramphenicol, ciprofloxacin killed cells under both conditions but required higher concentrations than those required with cells grown aerobically, C-methoxy fluoro quinolone was equally lethal under all conditions. However, lethal chromosome fragmentation, detected as a drop in viscosity in the absence of SDS, was occurred with nalidixic acid treatment only under aerobic conditions in the absence of chloramphenicol, thus, all quinolones tested appeared to form reversible bacteriostatic complexes containing broken DNA during aerobic growth, during anaerobic growth, and when protein synthesis is blocked. The ability to fragment chromosomes rapidly kill cells under these conditions depends on quinolone structure. The radiation of sublethal dose was 3 Gy at rate of 0.6 Gy/min was shown as non-significant result

  14. Uranium enrichment: technology, economics, capacity

    International Nuclear Information System (INIS)

    Large-scale enrichment of uranium has now been carried out for 40 years. While the gaseous diffusion process was the original choice of several countries and continues today to provide the major component of the world production of separative work, the last two decades have witnessed the development of a number of alternative processes for enrichment. These processes, which are being studied and deployed around the world, offer a wide range of technical and economic characteristics which will be useful in assuring adequate capacity to meet projected reactor fuel market needs through the rest of this century at competitive prices. With present uncertainties in future enriched uranium needs, it is apparent that flexibility in the deployment and operation of any enrichment process will be one of the prime considerations for the future. More economical production of separative work not only can have a beneficial impact on reactor fuel costs, but also tends to conserve natural uranium resources. This paper reviews the world scene in the enrichment component of the fuel cycle, including existing or planned commercial-scale facilities and announced R and D efforts on various processes

  15. Experimental otitis media in gerbils and chinchillas with Streptococcus pneumoniae, Haemophilus influenzae, and other aerobic and anaerobic bacteria.

    OpenAIRE

    Fulghum, R S; Brinn, J E; Smith, A M; Daniel, H J; Loesche, P J

    1982-01-01

    To ascertain the usefulness of Mongolian gerbils as an inbred model for otitis media, 52 Mongolian gerbils (Meriones unguiculatus, strain MONT/Tum) were compared with 26 chinchillas (Chinchilla laniger) for susceptibility to Streptococcus pneumoniae type 3. Haemophilus influenzae type b, and a polymicrobic culture including anaerobes (Streptococcus intermedius, Propionibacterium acnes, Staphylococcus epidermidis, and Corynebacterium sp.). Organisms were inoculated percutaneously into the supe...

  16. Fast Swinnex Filtration (FSF): A fast and robust sampling and extraction method suitable for metabolomics analysis of cultures grown in complex media

    DEFF Research Database (Denmark)

    McCloskey, Douglas; Utrilla, Jose; Naviaux, Robert K.;

    2015-01-01

    of a suitable method for anaerobic cultures grown in complex media. Given that a vast majority of bacteria are facultative or obligate anaerobes that grow to low biomass density and need to be cultured in complex media, a suitable sampling and extraction strategy for anaerobic cultures is needed. In this work......, we develop a fast-filtration method using pressuredriven Swinnex filters. We show that the method is fast enough to provide an accurate snapshot of intracellular metabolism, reduces matrix interference from the media to improve the number of compounds that can be detected, and is applicable...... to anaerobic and aerobic liquid cultures grown in a variety of culturing systems. Furthermore, we apply the fast filtration method to investigate differences in the absolute intracellular metabolite levels of anaerobic cultures grown in minimal and complex media....

  17. ANAEROBIC BIOLOGICAL TREATMENT OF PRODUCED WATER

    Energy Technology Data Exchange (ETDEWEB)

    John R. Gallagher

    2001-07-31

    During the production of oil and gas, large amounts of water are brought to the surface and must be disposed of in an environmentally sensitive manner. This is an especially difficult problem in offshore production facilities where space is a major constraint. The chief regulatory criterion for produced water is oil and grease. Most facilities have little trouble meeting this criterion using conventional oil-water separation technologies. However, some operations have significant amounts of naphthenic acids in the water that behave as oil and grease but are not well removed by conventional technologies. Aerobic biological treatment of naphthenic acids in simulated-produced water has been demonstrated by others; however, the system was easily overloaded by the large amounts of low-molecular-weight organic acids often found in produced waters. The objective of this research was to determine the ability of an anaerobic biological system to treat these organic acids in a simulated produced water and to examine the potential for biodegradation of the naphthenic acids in the anaerobic environment. A small fixed-film anaerobic biological reactor was constructed and adapted to treat a simulated produced water. The bioreactor was tubular, with a low-density porous glass packing material. The inocula to the reactor was sediment from a produced-water holding pond from a municipal anaerobic digester and two salt-loving methanogenic bacteria. During start-up, the feed to the reactor contained glucose as well as typical produced-water components. When glucose was used, rapid gas production was observed. However, when glucose was eliminated and the major organic component was acetate, little gas was generated. Methane production from acetate may have been inhibited by the high salt concentrations, by sulfide, or because of the lack, despite seeding, of microbes capable of converting acetate to methane. Toluene, a minor component of the produced water (0.1 g/L) was removed in the

  18. Anaerobic Microflora of Everglades Sediments: Effects of Nutrients on Population Profiles and Activities

    OpenAIRE

    Drake, H. L.; Aumen, N. G.; Kuhner, C.; Wagner, C.; Griesshammer, A.; Schmittroth, M.

    1996-01-01

    Everglades sediments (wetland soils) near sources of agricultural runoff had low redox potentials, were blackened with sulfide, and displayed high porewater phosphorus (total) concentrations and high water column conductivities. These sediments yielded 10(sup3)- to 10(sup4)-fold-higher numbers of culturable anaerobes, including methanogens, sulfate reducers, and acetate producers, than did sediments from Everglades and Lake Okeechobee comparative control sites not as directly associated with ...

  19. Comparison of various microbial inocula for the efficient anaerobic digestion of Laminaria hyperborea

    OpenAIRE

    Sutherland, Alastair D; Varela, J.

    2014-01-01

    Background: The hydrolysis of seaweed polysaccharides is the rate limiting step in anaerobic digestion (AD) of seaweeds. Seven different microbial inocula and a mixture of these (inoculum 8) were therefore compared in triplicate, each grown over four weeks in static culture for the ability to degrade Laminaria hyperborea seaweed and produce methane through AD. Results: All the inocula could degrade L. hyperborea and produce methane to some extent. However, an inoculum of slurry from a human s...

  20. Anaerobic digestion of microalgae as a necessary step to make microalgal biodiesel sustainable.

    OpenAIRE

    Sialve, Bruno; Bernet, Nicolas; Bernard, Olivier

    2009-01-01

    International audience The potential of microalgae as a source of biofuels and as a technological solution for CO2 fixation is subject to intense academic and industrial research. In the perspective of setting up massive cultures, the management of large quantities of residual biomass and the high amounts of fertilizers must be considered. Anaerobic digestion is a key process that can solve this waste issue as well as the economical and energetic balance of such a promising technology. Ind...