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Sample records for diverse anaerobic metabolic

  1. Intermediary metabolism in protists: a sequence-based view of facultative anaerobic metabolism in evolutionarily diverse eukaryotes.

    Science.gov (United States)

    Ginger, Michael L; Fritz-Laylin, Lillian K; Fulton, Chandler; Cande, W Zacheus; Dawson, Scott C

    2010-12-01

    Protists account for the bulk of eukaryotic diversity. Through studies of gene and especially genome sequences the molecular basis for this diversity can be determined. Evident from genome sequencing are examples of versatile metabolism that go far beyond the canonical pathways described for eukaryotes in textbooks. In the last 2-3 years, genome sequencing and transcript profiling has unveiled several examples of heterotrophic and phototrophic protists that are unexpectedly well-equipped for ATP production using a facultative anaerobic metabolism, including some protists that can (Chlamydomonas reinhardtii) or are predicted (Naegleria gruberi, Acanthamoeba castellanii, Amoebidium parasiticum) to produce H(2) in their metabolism. It is possible that some enzymes of anaerobic metabolism were acquired and distributed among eukaryotes by lateral transfer, but it is also likely that the common ancestor of eukaryotes already had far more metabolic versatility than was widely thought a few years ago. The discussion of core energy metabolism in unicellular eukaryotes is the subject of this review. Since genomic sequencing has so far only touched the surface of protist diversity, it is anticipated that sequences of additional protists may reveal an even wider range of metabolic capabilities, while simultaneously enriching our understanding of the early evolution of eukaryotes. Copyright © 2010 Elsevier GmbH. All rights reserved.

  2. Genome-centric resolution of microbial diversity, metabolism and interactions in anaerobic digestion.

    Science.gov (United States)

    Vanwonterghem, Inka; Jensen, Paul D; Rabaey, Korneel; Tyson, Gene W

    2016-09-01

    Our understanding of the complex interconnected processes performed by microbial communities is hindered by our inability to culture the vast majority of microorganisms. Metagenomics provides a way to bypass this cultivation bottleneck and recent advances in this field now allow us to recover a growing number of genomes representing previously uncultured populations from increasingly complex environments. In this study, a temporal genome-centric metagenomic analysis was performed of lab-scale anaerobic digesters that host complex microbial communities fulfilling a series of interlinked metabolic processes to enable the conversion of cellulose to methane. In total, 101 population genomes that were moderate to near-complete were recovered based primarily on differential coverage binning. These populations span 19 phyla, represent mostly novel species and expand the genomic coverage of several rare phyla. Classification into functional guilds based on their metabolic potential revealed metabolic networks with a high level of functional redundancy as well as niche specialization, and allowed us to identify potential roles such as hydrolytic specialists for several rare, uncultured populations. Genome-centric analyses of complex microbial communities across diverse environments provide the key to understanding the phylogenetic and metabolic diversity of these interactive communities. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  3. Early anaerobic metabolisms

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene; Rosing, Minik T; Bjerrum, Christian

    2006-01-01

    probably driven by the cycling of H2 and Fe2+ through primary production conducted by anoxygenic phototrophs. Interesting and dynamic ecosystems would have also been driven by the microbial cycling of sulphur and nitrogen species, but their activity levels were probably not so great. Despite the diversity......Before the advent of oxygenic photosynthesis, the biosphere was driven by anaerobic metabolisms. We catalogue and quantify the source strengths of the most probable electron donors and electron acceptors that would have been available to fuel early-Earth ecosystems. The most active ecosystems were...... of potential early ecosystems, rates of primary production in the early-Earth anaerobic biosphere were probably well below those rates observed in the marine environment. We shift our attention to the Earth environment at 3.8Gyr ago, where the earliest marine sediments are preserved. We calculate, consistent...

  4. Anaerobic energy metabolism in unicellular photosynthetic eukaryotes.

    Science.gov (United States)

    Atteia, Ariane; van Lis, Robert; Tielens, Aloysius G M; Martin, William F

    2013-02-01

    Anaerobic metabolic pathways allow unicellular organisms to tolerate or colonize anoxic environments. Over the past ten years, genome sequencing projects have brought a new light on the extent of anaerobic metabolism in eukaryotes. A surprising development has been that free-living unicellular algae capable of photoautotrophic lifestyle are, in terms of their enzymatic repertoire, among the best equipped eukaryotes known when it comes to anaerobic energy metabolism. Some of these algae are marine organisms, common in the oceans, others are more typically soil inhabitants. All these species are important from the ecological (O(2)/CO(2) budget), biotechnological, and evolutionary perspectives. In the unicellular algae surveyed here, mixed-acid type fermentations are widespread while anaerobic respiration, which is more typical of eukaryotic heterotrophs, appears to be rare. The presence of a core anaerobic metabolism among the algae provides insights into its evolutionary origin, which traces to the eukaryote common ancestor. The predicted fermentative enzymes often exhibit an amino acid extension at the N-terminus, suggesting that these proteins might be compartmentalized in the cell, likely in the chloroplast or the mitochondrion. The green algae Chlamydomonas reinhardtii and Chlorella NC64 have the most extended set of fermentative enzymes reported so far. Among the eukaryotes with secondary plastids, the diatom Thalassiosira pseudonana has the most pronounced anaerobic capabilities as yet. From the standpoints of genomic, transcriptomic, and biochemical studies, anaerobic energy metabolism in C. reinhardtii remains the best characterized among photosynthetic protists. This article is part of a Special Issue entitled: The evolutionary aspects of bioenergetic systems. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Teleosts in hypoxia : Aspects of anaerobic metabolism

    NARCIS (Netherlands)

    Van den Thillart, G.; van Waarde, Aren

    1985-01-01

    Moderate hypoxia can be tolerated by many fish species, while only some species survive severe hypoxia or anoxia. Hypoxia usually activates anaerobic glycolysis, which may be temporary when the animals are able to improve their oxygen extraction capacity. Switching over to aerobic metabolism allows

  6. Energy Metabolism during Anaerobic Methane Oxidation in ANME Archaea

    Science.gov (United States)

    McGlynn, Shawn E.

    2017-01-01

    Anaerobic methane oxidation in archaea is often presented to operate via a pathway of “reverse methanogenesis”. However, if the cumulative reactions of a methanogen are run in reverse there is no apparent way to conserve energy. Recent findings suggest that chemiosmotic coupling enzymes known from their use in methylotrophic and acetoclastic methanogens—in addition to unique terminal reductases—biochemically facilitate energy conservation during complete CH4 oxidation to CO2. The apparent enzyme modularity of these organisms highlights how microbes can arrange their energy metabolisms to accommodate diverse chemical potentials in various ecological niches, even in the extreme case of utilizing “reverse” thermodynamic potentials. PMID:28321009

  7. 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.

  8. Anaerobic Metabolism: Linkages to Trace Gases and Aerobic Processes

    Science.gov (United States)

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

    2003-12-01

    Life evolved and flourished in the absence of molecular oxygen (O2). As the O2 content of the atmosphere rose to the present level of 21% beginning about two billion years ago, anaerobic metabolism was gradually supplanted by aerobic metabolism. Anaerobic environments have persisted on Earth despite the transformation to an oxidized state because of the combined influence of water and organic matter. Molecular oxygen diffuses about 104 times more slowly through water than air, and organic matter supports a large biotic O2 demand that consumes the supply faster than it is replaced by diffusion. Such conditions exist in wetlands, rivers, estuaries, coastal marine sediments, aquifers, anoxic water columns, sewage digesters, landfills, the intestinal tracts of animals, and the rumen of herbivores. Anaerobic microsites are also embedded in oxic environments such as upland soils and marine water columns. Appreciable rates of aerobic respiration are restricted to areas that are in direct contact with air or those inhabited by organisms that produce O2.Rising atmospheric O2 reduced the global area of anaerobic habitat, but enhanced the overall rate of anaerobic metabolism (at least on an area basis) by increasing the supply of electron donors and acceptors. Organic carbon production increased dramatically, as did oxidized forms of nitrogen, manganese, iron, sulfur, and many other elements. In contemporary anaerobic ecosystems, nearly all of the reducing power is derived from photosynthesis, and most of it eventually returns to O2, the most electronegative electron acceptor that is abundant. This photosynthetically driven redox gradient has been thoroughly exploited by aerobic and anaerobic microorganisms for metabolism. The same is true of hydrothermal vents (Tunnicliffe, 1992) and some deep subsurface environments ( Chapelle et al., 2002), where thermal energy is the ultimate source of the reducing power.Although anaerobic habitats are currently a small fraction of Earth

  9. Benznidazole induces in vitro anaerobic metabolism in Trypanosoma cruzi epimastigotes

    Directory of Open Access Journals (Sweden)

    Marina Clare Vinaud

    2017-11-01

    Full Text Available Objective: To determine the biochemical alterations of the energetic metabolism of Trypanosoma cruzi epimastigotes in vitro exposed to different concentrations of benzinidazole. Methods: Biochemical analyses were performed at 3, 6 (log phase, 9 and 12 (stationary phase days of culture. Parasites were exposed to five concentrations of benzinidazole. Glycolysis, tricarboxilic acid cycle and fatty acids oxidation pathways were quantified through chromatography. Glucose, urea and creatinine were quantified through spectrophotometric analysis. Results: Anaerobic fermentation and fatty acids oxidation were increased in the stationary phase of the culture. Benzinidazole at high concentrations induced anaerobic metabolism in the log phase of the culture while the parasites exposed to the lower concentrations preferred the citric acid cycle as energy production pathway. Benzinidazole did not influence on the proteins catabolism. Conclusions: It is possible to conclude that there are metabolic differences between evolutive forms of Trypanosoma cruzi and the main drug used for its treatment induces the anaerobic metabolism in the parasite, possibly impairing the mitochondrial pathways.

  10. CAN THE END PRODUCTS OF ANAEROBIC METABOLISM ...

    African Journals Online (AJOL)

    Exercise, primarily powered by the shell adductor muscle, was mainly fueled by ... in seawater) transportation stress of up to 36 h at 7 and 10°C, clearly showed that ... at 10°C), indicating that aerobic metabolism is impaired at an early stage of ...

  11. Summer investigations into the metabolic diversity of the microbial world

    Energy Technology Data Exchange (ETDEWEB)

    Breznak, J.; Dworkin, M.

    1993-05-17

    The philosophy of the course described here is to underscore the essence of microbiology which is diversity>: diversity of morphology and cellular development, behavior, and metabolic and physiological functions. Emphasis is on microbes other than those customarily covered in conventional microbiology courses and includes: the archaebacteria, extremophiles, and array of obligate anaerobes, various phototrophs, and those microbes exhibiting complex developmental cycles. Also included are microbes carrying out a variety of transformations of organic and inorganic compounds, as well as those which normally occur in symbiotic association with other microbes or with higher forms of life.

  12. The anaerobic phototrophic metabolism of 3-chlorobenzoate by Rhodopseudomonas palustris

    Energy Technology Data Exchange (ETDEWEB)

    Kamal, V S

    1992-10-09

    The degradation of chlorinated aromatic compounds by anaerobic bacteria is now known to be an important mechanism of bioremediation. In an experimental study, a mixed phototrophic culture was found to metabolize 3-chlorobenzoate in the presence of benzoate following adaptation on a benzoate and 3-chlorobenzoate medium for 7 weeks. The dominant bacterial isolate was identified as Rhodopseudomonas palustris. Radioisotopic studies showed [sup 14]C-3-chlorobenzoate was converted by the isolate to [sup 14]CO[sub 2] and cell biomass in the absence of oxygen and in the presence of a cosubstrate red light. Cyclohexane carboxylate was able to replace the cosubstrate, benzoate. The isolate also metabolized 3-chlorobenzoate in the presence of pimelic acid, sodium acetate, and sodium succinate; however, the metabolic rate was reduced. Gas chromatography mass spectrometry and high pressure liquid chromatography indicated the intracellular presence of 3-chlorobenzoate and benzoyl-CoA. Cell-free extracts produced benzoate and benzoyl-CoA. A probable route of 3-chlorobenzoate metabolism via dehalogenation followed by steps similar to the benzoate reductive ring fission pathway is suggested. Comparison of kinetic coefficients showed a higher affinity of the isolate for benzoate. Isolates from representative samples of various freshwater and wastewater ecosystems indicated widespread ecological distribution of R. palustris and the common occurrence of the 3-chlorobenzoate metabolic phenotype. R. palustris was found to grow in mixed anaerobic cultures and retained its 3-chlorobenzoate degradation property. 91 refs., 25 figs., 14 tabs.

  13. Global niche of marine anaerobic metabolisms expanded by particle microenvironments

    Science.gov (United States)

    Bianchi, Daniele; Weber, Thomas S.; Kiko, Rainer; Deutsch, Curtis

    2018-04-01

    In ocean waters, anaerobic microbial respiration should be confined to the anoxic waters found in coastal regions and tropical oxygen minimum zones, where it is energetically favourable. However, recent molecular and geochemical evidence has pointed to a much broader distribution of denitrifying and sulfate-reducing microbes. Anaerobic metabolisms are thought to thrive in microenvironments that develop inside sinking organic aggregates, but the global distribution and geochemical significance of these microenvironments is poorly understood. Here, we develop a new size-resolved particle model to predict anaerobic respiration from aggregate properties and seawater chemistry. Constrained by observations of the size spectrum of sinking particles, the model predicts that denitrification and sulfate reduction can be sustained throughout vast, hypoxic expanses of the ocean, and could explain the trace metal enrichment observed in particles due to sulfide precipitation. Globally, the expansion of the anaerobic niche due to particle microenvironments doubles the rate of water column denitrification compared with estimates based on anoxic zones alone, and changes the sensitivity of the marine nitrogen cycle to deoxygenation in a warming climate.

  14. Diversity Profile of Microbes Associated with Anaerobic Sulfur Oxidation in an Upflow Anaerobic Sludge Blanket Reactor Treating Municipal Sewage

    Science.gov (United States)

    Aida, Azrina A.; Kuroda, Kyohei; Yamamoto, Masamitsu; Nakamura, Akinobu; Hatamoto, Masashi; Yamaguchi, Takashi

    2015-01-01

    We herein analyzed the diversity of microbes involved in anaerobic sulfur oxidation in an upflow anaerobic sludge blanket (UASB) reactor used for treating municipal sewage under low-temperature conditions. Anaerobic sulfur oxidation occurred in the absence of oxygen, with nitrite and nitrate as electron acceptors; however, reactor performance parameters demonstrated that anaerobic conditions were maintained. In order to gain insights into the underlying basis of anaerobic sulfur oxidation, the microbial diversity that exists in the UASB sludge was analyzed comprehensively to determine their identities and contribution to sulfur oxidation. Sludge samples were collected from the UASB reactor over a period of 2 years and used for bacterial 16S rRNA gene-based terminal restriction fragment length polymorphism (T-RFLP) and next-generation sequencing analyses. T-RFLP and sequencing results both showed that microbial community patterns changed markedly from day 537 onwards. Bacteria belonging to the genus Desulforhabdus within the phylum Proteobacteria and uncultured bacteria within the phylum Fusobacteria were the main groups observed during the period of anaerobic sulfur oxidation. Their abundance correlated with temperature, suggesting that these bacterial groups played roles in anaerobic sulfur oxidation in UASB reactors. PMID:25817585

  15. Microbial Diversity and Characteristics in Anaerobic Environments in KURT Groundwater

    International Nuclear Information System (INIS)

    Roh, Yul; Oh, Jong Min; Rhee, Sung Keun; Yong, Jong Joong

    2008-03-01

    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

  16. Metabolic interactions between methanogenic consortia and anaerobic respiring bacteria

    DEFF Research Database (Denmark)

    Stams, A.J.; Oude Elferink, S.J.; Westermann, Peter

    2003-01-01

    Most types of anaerobic respiration are able to outcompete methanogenic consortia for common substrates if the respective electron acceptors are present in sufficient amounts. Furthermore, several products or intermediate compounds formed by anaerobic respiring bacteria are toxic to methanogenic...... consortia. Despite the potentially adverse effects, only few inorganic electron acceptors potentially utilizable for anaerobic respiration have been investigated with respect to negative interactions in anaerobic digesters. In this chapter we review competitive and inhibitory interactions between anaerobic...... respiring populations and methanogenic consortia in bioreactors. Due to the few studies in anaerobic digesters, many of our discussions are based upon studies of defined cultures or natural ecosystems...

  17. Anaerobic 4-hydroxyproline utilization: Discovery of a new glycyl radical enzyme in the human gut microbiome uncovers a widespread microbial metabolic activity.

    Science.gov (United States)

    Huang, Yolanda Y; Martínez-Del Campo, Ana; Balskus, Emily P

    2018-02-06

    The discovery of enzymes responsible for previously unappreciated microbial metabolic pathways furthers our understanding of host-microbe and microbe-microbe interactions. We recently identified and characterized a new gut microbial glycyl radical enzyme (GRE) responsible for anaerobic metabolism of trans-4-hydroxy-l-proline (Hyp). Hyp dehydratase (HypD) catalyzes the removal of water from Hyp to generate Δ 1 -pyrroline-5-carboxylate (P5C). This enzyme is encoded in the genomes of a diverse set of gut anaerobes and is prevalent and abundant in healthy human stool metagenomes. Here, we discuss the roles HypD may play in different microbial metabolic pathways as well as the potential implications of this activity for colonization resistance and pathogenesis within the human gut. Finally, we present evidence of anaerobic Hyp metabolism in sediments through enrichment culturing of Hyp-degrading bacteria, highlighting the wide distribution of this pathway in anoxic environments beyond the human gut.

  18. Metagenomic insights into anaerobic metabolism along an Arctic peat soil profile.

    Directory of Open Access Journals (Sweden)

    David A Lipson

    Full Text Available A metagenomic analysis was performed on a soil profile from a wet tundra site in northern Alaska. The goal was to link existing biogeochemical knowledge of the system with the organisms and genes responsible for the relevant metabolic pathways. We specifically investigated how the importance of iron (Fe oxides and humic substances (HS as terminal electron acceptors in this ecosystem is expressed genetically, and how respiratory and fermentative processes varied with soil depth into the active layer and into the upper permafrost. Overall, the metagenomes reflected a microbial community enriched in a diverse range of anaerobic pathways, with a preponderance of known Fe reducing species at all depths in the profile. The abundance of sequences associated with anaerobic metabolic processes generally increased with depth, while aerobic cytochrome c oxidases decreased. Methanogenesis genes and methanogen genomes followed the pattern of CH4 fluxes: they increased steeply with depth into the active layer, but declined somewhat over the transition zone between the lower active layer and the upper permafrost. The latter was relatively enriched in fermentative and anaerobic respiratory pathways. A survey of decaheme cytochromes (MtrA, MtrC and their homologs revealed that this is a promising approach to identifying potential reducers of Fe(III or HS, and indicated a possible role for Acidobacteria as Fe reducers in these soils. Methanogens appear to coexist in the same layers, though in lower abundance, with Fe reducing bacteria and other potential competitors, including acetogens. These observations provide a rich set of hypotheses for further targeted study.

  19. Amino acid metabolism conflicts with protein diversity

    OpenAIRE

    Krick, Teresa; Shub, David A.; Verstraete, Nina; Ferreiro, Diego U.; Alonso, Leonardo G.; Shub, Michael; Sanchez, Ignacio E.

    2014-01-01

    The 20 protein-coding amino acids are found in proteomes with different relative abundances. The most abundant amino acid, leucine, is nearly an order of magnitude more prevalent than the least abundant amino acid, cysteine. Amino acid metabolic costs differ similarly, constraining their incorporation into proteins. On the other hand, a diverse set of protein sequences is necessary to build functional proteomes. Here, we present a simple model for a cost-diversity trade-off postulating that n...

  20. The anaerobic linalool metabolism in Thauera linaloolentis 47 Lol.

    Science.gov (United States)

    Marmulla, Robert; Cala, Edinson Puentes; Markert, Stephanie; Schweder, Thomas; Harder, Jens

    2016-04-27

    The betaproteobacterium Thauera linaloolentis 47Lol(T) was isolated on the tertiary monoterpene alcohol (R,S)-linalool as sole carbon and energy source under denitrifying conditions. Growth experiments indicated the formation of geraniol and geranial. Thus, a 3,1-hydroxyl-Δ(1)-Δ(2)-mutase (linalool isomerase) activity may initiate the degradation, followed by enzymes of the acyclic terpene utilization (Atu) and leucine/isovalerate utilization (Liu) pathways that were extensively studied in Pseudomonas spp. growing on citronellol or geraniol. A transposon mutagenesis yielded 39 transconjugants that could not grow anaerobically on linalool and nitrate in liquid medium. The deficiencies were apparently based on gene functions required to overcome the toxicity of linalool, but not due to inactivation of genes in the degradation pathway. Growing cultures formed geraniol and geranial transiently, but also geranic acid. Analysis of expressed proteins detected several enzymes of the Atu and Liu pathways. The draft genome of T. linaloolentis 47Lol(T) had atu and liu genes with homology to those of Pseudomonas spp.. The in comparison to monoterpenes larger toxicity of monoterpene alcohols is defeated by several modifications of the cellular structure and metabolism in Thauera linaloolentis 47Lol(T). The acyclic terpene utilization pathway is used in T. linaloolentis 47Lol(T) during growth on (R,S)-linalool and nitrate under anoxic conditions. This is the first experimental verification of an active Atu pathway outside of the genus Pseudomonas.

  1. Metabolic Effects of Berries with Structurally Diverse Anthocyanins

    Directory of Open Access Journals (Sweden)

    John Overall

    2017-02-01

    Full Text Available Overconsumption of energy dense foods and sedentary lifestyle are considered as major causes of obesity-associated insulin resistance and abnormal glucose metabolism. Results from both cohort studies and randomized trials suggested that anthocyanins from berries may lower metabolic risks, however these reports are equivocal. The present study was designed to examine effects of six berries with structurally diverse anthocyanin profiles (normalized to 400 µg/g total anthocyanin content on development of metabolic risk factors in the C57BL/6 mouse model of polygenic obesity. Diets supplemented with blackberry (mono-glycosylated cyanidins, black raspberry (acylated mono-glycosylated cyanidins, blackcurrant (mono- and di-glycosylated cyanidins and delphinidins, maqui berry (di-glycosylated delphinidins, Concord grape (acylated mono-glycosylated delphinidins and petunidins, and blueberry (mono-glycosylated delphinidins, malvidins, and petunidins showed a prominent discrepancy between biological activities of delphinidin/malvidin-versus cyanidin-type anthocyanins that could be explained by differences in their structure and metabolism in the gut. Consumption of berries also resulted in a strong shift in the gastrointestinal bacterial communities towards obligate anaerobes that correlated with decrease in the gastrointestinal luminal oxygen and oxidative stress. Further work is needed to understand mechanisms that lead to nearly anoxic conditions in the gut lumens, including the relative contributions of host, diet and/or microbial oxidative activity, and their implication to human health.

  2. Performance and diversity of polyvinyl alcohol-degrading bacteria under aerobic and anaerobic conditions.

    Science.gov (United States)

    Huang, Jianping; Yang, Shisu; Zhang, Siqi

    2016-11-01

    To compare the degradation performance and biodiversity of a polyvinyl alcohol-degrading microbial community under aerobic and anaerobic conditions. An anaerobic-aerobic bioreactor was operated to degrade polyvinyl alcohol (PVA) in simulated wastewater. The degradation performance of the bioreactor during sludge cultivation and the microbial communities in each reactor were compared. Both anaerobic and aerobic bioreactors demonstrated high chemical oxygen demand removal efficiencies of 87.5 and 83.6 %, respectively. Results of 16S rDNA sequencing indicated that Proteobacteria dominated in both reactors and that the microbial community structures varied significantly under different operating conditions. Both reactors obviously differed in bacterial diversity from the phyla Planctomycetes, Chlamydiae, Bacteroidetes, and Chloroflexi. Betaproteobacteria and Alphaproteobacteria dominated, respectively, in the anaerobic and aerobic reactors. The anaerobic-aerobic system is suitable for PVA wastewater treatment, and the microbial genetic analysis may serve as a reference for PVA biodegradation.

  3. Diversity and ubiquity of bacteria capable of utilizing humic substances as electron donors for anaerobic respiration.

    Science.gov (United States)

    Coates, John D; Cole, Kimberly A; Chakraborty, Romy; O'Connor, Susan M; Achenbach, Laurie A

    2002-05-01

    Previous studies have demonstrated that reduced humic substances (HS) can be reoxidized by anaerobic bacteria such as Geobacter, Geothrix, and Wolinella species with a suitable electron acceptor; however, little is known of the importance of this metabolism in the environment. Recently we investigated this metabolism in a diversity of environments including marine and aquatic sediments, forest soils, and drainage ditch soils. Most-probable-number enumeration studies were performed using 2,6-anthrahydroquinone disulfonate (AHDS), an analog for reduced HS, as the electron donor with nitrate as the electron acceptor. Anaerobic organisms capable of utilizing reduced HS as an electron donor were found in all environments tested and ranged from a low of 2.31 x 10(1) in aquifer sediments to a high of 9.33 x 10(6) in lake sediments. As part of this study we isolated six novel organisms capable of anaerobic AHDS oxidation. All of the isolates coupled the oxidation of AHDS to the reduction of nitrate with acetate (0.1 mM) as the carbon source. In the absence of cells, no AHDS oxidation was apparent, and in the absence of AHDS, no cell density increase was observed. Generally, nitrate was reduced to N(2). Analysis of the AHDS and its oxidized form, 2,6-anthraquinone disulfonate (AQDS), in the medium during growth revealed that the anthraquinone was not being biodegraded as a carbon source and was simply being oxidized as an energy source. Determination of the AHDS oxidized and nitrate reduced accounted for 109% of the theoretical electron transfer. In addition to AHDS, all of these isolates could also couple the oxidation of reduced humic substances to the reduction of nitrate. No HS oxidation occurred in the absence of cells and in the absence of a suitable electron acceptor, demonstrating that these organisms were capable of utilizing natural HS as an energy source and that AHDS serves as a suitable analog for studying this metabolism. Alternative electron donors included

  4. Identification of genes specifically required for the anaerobic metabolism of benzene in Geobacter metallireducens

    DEFF Research Database (Denmark)

    Zhang, Tian; Tremblay, Pier-Luc; Chaurasia, Akhilesh Kumar

    2014-01-01

    Although the biochemical pathways for the anaerobic degradation of many of the hydrocarbon constituents in petroleum reservoirs have been elucidated, the mechanisms for anaerobic activation of benzene, a very stable molecule, are not known. Previous studies have demonstrated that Geobacter...... metallireducens can anaerobically oxidize benzene to carbon dioxide with Fe(III) as the sole electron acceptor and that phenol is an intermediate in benzene oxidation. In an attempt to identify enzymes that might be involved in the conversion of benzene to phenol, whole-genome gene transcript abundance...... was compared in cells metabolizing benzene and cells metabolizing phenol. Eleven genes had significantly higher transcript abundance in benzene-metabolizing cells. Five of these genes had annotations suggesting that they did not encode proteins that could be involved in benzene metabolism and were not further...

  5. Metabolism of Hydrocarbons in n-Alkane-Utilizing Anaerobic Bacteria.

    Science.gov (United States)

    Wilkes, Heinz; Buckel, Wolfgang; Golding, Bernard T; Rabus, Ralf

    2016-01-01

    The glycyl radical enzyme-catalyzed addition of n-alkanes to fumarate creates a C-C-bond between two concomitantly formed stereogenic carbon centers. The configurations of the two diastereoisomers of the product resulting from n-hexane activation by the n-alkane-utilizing denitrifying bacterium strain HxN1, i.e. (1-methylpentyl)succinate, were assigned as (2S,1'R) and (2R,1'R). Experiments with stereospecifically deuterated n-(2,5-2H2)hexanes revealed that exclusively the pro-S hydrogen atom is abstracted from C2 of the n-alkane by the enzyme and later transferred back to C3 of the alkylsuccinate formed. These results indicate that the alkylsuccinate-forming reaction proceeds with an inversion of configuration at the carbon atom (C2) of the n-alkane forming the new C-C-bond, and thus stereochemically resembles a SN2-type reaction. Therefore, the reaction may occur in a concerted manner, which may avoid the highly energetic hex-2-yl radical as an intermediate. The reaction is associated with a significant primary kinetic isotope effect (kH/kD ≥3) for hydrogen, indicating that the homolytic C-H-bond cleavage is involved in the first irreversible step of the reaction mechanism. The (1-methylalkyl)succinate synthases of n-alkane-utilizing anaerobic bacteria apparently have very broad substrate ranges enabling them to activate not only aliphatic but also alkyl-aromatic hydrocarbons. Thus, two denitrifiers and one sulfate reducer were shown to convert the nongrowth substrate toluene to benzylsuccinate and further to the dead-end product benzoyl-CoA. For this purpose, however, the modified β-oxidation pathway known from alkylbenzene-utilizing bacteria was not employed, but rather the pathway used for n-alkane degradation involving CoA ligation, carbon skeleton rearrangement and decarboxylation. Furthermore, various n-alkane- and alkylbenzene-utilizing denitrifiers and sulfate reducers were found to be capable of forming benzyl alcohols from diverse alkylbenzenes

  6. Aspects of anaerobic metabolism in Anodonta cygnea L.

    NARCIS (Netherlands)

    Holwerda, Dirk A.; Veenhof, P.R.

    1984-01-01

    1. After 6 days of anoxia A. cygnea had produced 1.0 µmole succinate, 2.7 µmole propionate and 1.7 µmole acetate/g of total soft tissue (wet). In addition, 0.35 µmole glutamate had disappeared. No other changes were detectable. 2. Concentrations of anaerobic end products and of amino acids

  7. Partitioning the metabolic scope: the importance of anaerobic metabolism and implications for the oxygen- and capacity-limited thermal tolerance (OCLTT) hypothesis

    DEFF Research Database (Denmark)

    Ejbye-Ernst, Rasmus; Michaelsen, Thomas Y.; Tirsgaard, B.

    2016-01-01

    . aurata. In contrast, both species revealed significant negative correlations between aerobic and anaerobic components of the MS, indicating a trade-off where both components of the MS cannot be optimized simultaneously. Importantly, the fraction of the MS influenced by anaerobic metabolism was on average...... 24.3 and 26.1% in S. aurata and P. reticulata, respectively. These data highlight the importance of taking anaerobic metabolism into account when assessing effects of environmental variation on the MS, because the fraction where anaerobic metabolism occurs is a poor indicator of sustainable aerobic...

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

    International Nuclear Information System (INIS)

    Kleerebezem, R.; Temudo, M.; Muyzer Van Loosdrecht, M. C. M.

    2009-01-01

    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)

  9. Significance of anaerobic bacteria in postoperative infection after radical cystectomy and urinary diversion or reconstruction.

    Science.gov (United States)

    Hiyama, Yoshiki; Takahashi, Satoshi; Uehara, Teruhisa; Hashimoto, Jiro; Kurimura, Yuichiro; Tanaka, Toshiaki; Masumori, Naoya; Tsukamoto, Taiji

    2013-10-01

    Radical cystectomy followed by urinary diversion or reconstruction (RC) is a standard treatment for patients with muscle-invasive bladder cancer. In these operations, a high frequency of complications, especially postoperative infection, has been reported. However, there have only been a few studies about postoperative anaerobic bacterial infection. To clarify the significance and role of anaerobic bacteria in postoperative infection, we retrospectively analyzed cases in which postoperative infection by these organisms developed. A total of 126 patients who underwent RC from 2006 to 2010 were included in this study. Various types of postoperative infection occurred in 66 patients. Anaerobic bacterial infections were detected with cultures for urine and blood in one case, for blood in two cases, and for surgical wound pus in four. The frequency of postoperative anaerobic bacterial infection in RC was less than that of colon surgery. However, this study revealed the possible development of a nonnegligible number of postoperative anaerobic bacterial infections. Therefore, we should consider anaerobic bacteria as possible pathogens in postoperative infection after RC.

  10. Diversity of Cultured Thermophilic Anaerobes in Hot Springs of Yunnan Province, China

    Science.gov (United States)

    Lin, L.; Lu, Y.; Dong, X.; Liu, X.; Wei, Y.; Ji, X.; Zhang, C.

    2010-12-01

    Thermophilic anaerobes including Archaea and Bacteria refer to those growing optimally at temperatures above 50°C and do not use oxygen as the terminal electron acceptor for growth. Study on thermophilic anaerobes will help to understand how life thrives under extreme conditions. Meanwhile thermophilic anaerobes are of importance in potential application and development of thermophilic biotechnology. We have surveyed culturable thermophilic anaerobes in hot springs (pH6.5-7.5; 70 - 94°C) in Rehai of Tengchong, Bangnazhang of Longlin, Eryuan of Dali,Yunnan, China. 50 strains in total were cultured from the hot springs water using Hungate anaerobic technique, and 30 strains were selected based on phenotypic diversity for analysis of 16S rDNA sequences. Phylogenetic analysis showed that 28 strains belonged to the members of five genera: Caldanaerobacter, Calaramator, Thermoanaerobacter, Dictyoglomus and Fervidobacterium, which formed five branches on the phylogenetic tree. Besides, 2 strains of methanogenic archaea were obtained. The majority of the isolates were the known species, however, seven strains were identified as novel species affiliated to the five genera based on the lower 16S rDNA sequence similarities (less than 93 - 97%) with the described species. This work would provide the future study on their diversity, distribution among different regions and the potential application of thermophilic enzyme. Supported by State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences(SKLMR-080605)and the Foundation of State Natural Science (30660009, 30960022, 31081220175).

  11. Limited Influence of Oxygen on the Evolution of Chemical Diversity in Metabolic Networks

    Directory of Open Access Journals (Sweden)

    Kazuhiro Takemoto

    2013-10-01

    Full Text Available Oxygen is thought to promote species and biomolecule diversity. Previous studies have suggested that oxygen expands metabolic networks by acquiring metabolites with different chemical properties (higher hydrophobicity, for example. However, such conclusions are typically based on biased evaluation, and are therefore non-conclusive. Thus, we re-investigated the effect of oxygen on metabolic evolution using a phylogenetic comparative method and metadata analysis to reduce the bias as much as possible. Notably, we found no difference in metabolic network expansion between aerobes and anaerobes when evaluating phylogenetic relationships. Furthermore, we showed that previous studies have overestimated or underestimated the degrees of differences in the chemical properties (e.g., hydrophobicity between oxic and anoxic metabolites in metabolic networks of unicellular organisms; however, such overestimation was not observed when considering the metabolic networks of multicellular organisms. These findings indicate that the contribution of oxygen to increased chemical diversity in metabolic networks is lower than previously thought; rather, phylogenetic signals and cell-cell communication result in increased chemical diversity. However, this conclusion does not contradict the effect of oxygen on metabolic evolution; instead, it provides a deeper understanding of how oxygen contributes to metabolic evolution despite several limitations in data analysis methods.

  12. Chiling slows anaerobic metabolism to improve anoxia tolerance of insects

    Czech Academy of Sciences Publication Activity Database

    Boardman, L.; Sorensen, J. G.; Košťál, Vladimír; Šimek, Petr; Terblanche, J. S.

    2016-01-01

    Roč. 12, č. 12 (2016), č. článku 176. ISSN 1573-3882 R&D Projects: GA ČR GA13-18509S Institutional support: RVO:60077344 Keywords : anoxia * anaerobism * cold tolerance Subject RIV: ED - Physiology Impact factor: 3.692, year: 2016 http://link.springer.com/article/10.1007/s11306-016-1119-1

  13. Modeling microbial diversity in anaerobic digestion through an extended ADM1 model.

    Science.gov (United States)

    Ramirez, Ivan; Volcke, Eveline I P; Rajinikanth, Rajagopal; Steyer, Jean-Philippe

    2009-06-01

    The anaerobic digestion process comprises a whole network of sequential and parallel reactions, of both biochemical and physicochemical nature. Mathematical models, aiming at understanding and optimization of the anaerobic digestion process, describe these reactions in a structured way, the IWA Anaerobic Digestion Model No. 1 (ADM1) being the most well established example. While these models distinguish between different microorganisms involved in different reactions, to our knowledge they all neglect species diversity between organisms with the same function, i.e. performing the same reaction. Nevertheless, available experimental evidence suggests that the structure and properties of a microbial community may be influenced by process operation and on their turn also determine the reactor functioning. In order to adequately describe these phenomena, mathematical models need to consider the underlying microbial diversity. This is demonstrated in this contribution by extending the ADM1 to describe microbial diversity between organisms of the same functional group. The resulting model has been compared with the traditional ADM1 in describing experimental data of a pilot-scale hybrid Upflow Anaerobic Sludge Filter Bed (UASFB) reactor, as well as in a more detailed simulation study. The presented model is further shown useful in assessing the relationship between reactor performance and microbial community structure in mesophilic CSTRs seeded with slaughterhouse wastewater when facing increasing levels of ammonia.

  14. Harnessing natural diversity to probe metabolic pathways.

    Directory of Open Access Journals (Sweden)

    Oliver R Homann

    2005-12-01

    Full Text Available Analyses of cellular processes in the yeast Saccharomyces cerevisiae rely primarily upon a small number of highly domesticated laboratory strains, leaving the extensive natural genetic diversity of the model organism largely unexplored and unexploited. We asked if this diversity could be used to enrich our understanding of basic biological processes. As a test case, we examined a simple trait: the utilization of di/tripeptides as nitrogen sources. The capacity to import small peptides is likely to be under opposing selective pressures (nutrient utilization versus toxin vulnerability and may therefore be sculpted by diverse pathways and strategies. Hitherto, dipeptide utilization in S. cerevisiae was solely ascribed to the activity of a single protein, the Ptr2p transporter. Using high-throughput phenotyping and several genetically diverse strains, we identified previously unknown cellular activities that contribute to this trait. We find that the Dal5p allantoate/ureidosuccinate permease is also capable of facilitating di/tripeptide transport. Moreover, even in the absence of Dal5p and Ptr2p, an additional activity--almost certainly the periplasmic asparaginase II Asp3p--facilitates the utilization of dipeptides with C-terminal asparagine residues by a different strategy. Another, as-yet-unidentified activity enables the utilization of dipeptides with C-terminal arginine residues. The relative contributions of these activities to the utilization of di/tripeptides vary among the strains analyzed, as does the vulnerability of these strains to a toxic dipeptide. Only by sampling the genetic diversity of multiple strains were we able to uncover several previously unrecognized layers of complexity in this metabolic pathway. High-throughput phenotyping facilitates the rapid exploration of the molecular basis of biological complexity, allowing for future detailed investigation of the selective pressures that drive microbial evolution.

  15. Low cerebral blood flow after cardiac arrest is not associated with anaerobic cerebral metabolism

    NARCIS (Netherlands)

    Hoedemaekers, C.W.E.; Ainslie, Philip N.; Hinssen, S.; Aries, M.J.; Bisschops, Laurens L.; Hofmeijer, Jeannette; van der Hoeven, J.G.

    2017-01-01

    Aim of the study Estimation of cerebral anaerobic metabolism in survivors and non-survivors after cardiac arrest. Methods We performed an observational study in twenty comatose patients after cardiac arrest and 19 healthy control subjects. We measured mean flow velocity in the middle cerebral artery

  16. Increased ratio between anaerobic and aerobic metabolism in lymphocytes from hyperthyroid patients.

    Science.gov (United States)

    Valdemarsson, S; Monti, M

    1994-03-01

    While an increased oxygen consumption is accepted as one consequence of hyperthyroidism, only few data are available on the role of anaerobic processes for the increased metabolic activity in this disease. In this study we evaluated the relative importance of anaerobic and aerobic metabolism for the metabolic activity in lymphocytes from patients before and after treatment for hyperthyroidism. Total lymphocyte heat production rate (P), reflecting total cell metabolic activity, was determined in a plasma lymphocyte suspension using direct microcalorimetry. The contribution from aerobic metabolism (O2-P) was calculated from the product of the lymphocyte oxygen consumption rate and the enthalpy change for glucose combustion, and the anaerobic contribution as the difference between P and O2-P. The total lymphocyte heat production rate P was 3.37 +/- 0.25 (SEM) pW/cell (N = 11) before and 2.50 +/- 0.11 pW/cell (N = 10) after treatment for hyperthyroidism (p hyperthyroid state and to 73.7 +/- 3.2% after treatment (p metabolic activity demonstrated in lymphocytes from hyperthyroid patients cannot be explained by an increased oxygen-dependent consumption.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Assessment of anaerobic bacterial diversity and its effects on anaerobic system stability and the occurrence of antibiotic resistance genes.

    Science.gov (United States)

    Aydin, Sevcan; Ince, Bahar; Ince, Orhan

    2016-05-01

    This study evaluated the link between anaerobic bacterial diversity and, the biodegradation of antibiotic combinations and assessed how amending antibiotic combination and increasing concentration of antibiotics in a stepwise fashion influences the development of resistance genes in anaerobic reactors. The biodegradation, sorption and occurrence of the known antibiotic resistance genes (ARGs) of erythromycin and tetracycline were investigated using the processes of UV-HPLC and qPCR analysis respectively. Ion Torrent sequencing was used to detect microbial community changes in response to the addition of antibiotics. The overall results indicated that changes in the structure of a microbial community lead to changes in biodegradation capacity, sorption of antibiotics combinations and occurrence of ARGs. The enhanced biodegradation efficiency appeared to generate variations in the structure of the bacterial community. The results suggested that controlling the ultimate Gram-negative bacterial community, especially Acinetobacter-related populations, may promote the successful biodegradation of antibiotic combinations and reduce the occurrence of ARGs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Inhibition of microbial metabolism in anaerobic lagoons by selected sulfonamides, tetracyclines, lincomycin, and tylosin tartrate

    Science.gov (United States)

    Loftin, Keith A.; Henny, Cynthia; Adams, Craig D.; Surampali, Rao; Mormile, Melanie R.

    2005-01-01

    Antibiotics are used to maintain healthy livestock and to promote weight gain in concentrated animal feed operations. Antibiotics rarely are metabolized completely by livestock and, thus, are often present in livestock waste and in waste-treatment lagoons. The introduction of antibiotics into anaerobic lagoons commonly used for swine waste treatment has the potential for negative impacts on lagoon performance, which relies on a consortium of microbes ranging from fermentative microorganisms to methanogens. To address this concern, the effects of eight common veterinary antibiotics on anaerobic activity were studied. Anaerobic microcosms, prepared from freshly collected lagoon slurries, were amended with individual antibiotics at 10 mg/L for the initial screening study and at 1, 5, and 25 mg/L for the dose-response study. Monitored metabolic indicators included hydrogen, methane, and volatile fatty acid concentrations as well as chemical oxygen demand. The selected antibiotics significantly inhibited methane production relative to unamended controls, thus indicating that antibiotics at concentrations commonly found in swine lagoons can negatively impact anaerobic metabolism. Additionally, historical antibiotic usage seems to be a potential factor in affecting methane production. Specifically, less inhibition of methane production was noted in samples taken from the lagoon with a history of multiple-antibiotic use.

  19. Inhibition of microbial metabolism in anaerobic lagoons by selected sulfonamides, tetracyclines, lincomycin, and tylosin tartrate.

    Science.gov (United States)

    Loftin, Keith A; Henny, Cynthia; Adams, Craig D; Surampali, Rao; Mormile, Melanie R

    2005-04-01

    Antibiotics are used to maintain healthy livestock and to promote weight gain in concentrated animal feed operations. Antibiotics rarely are metabolized completely by livestock and, thus, are often present in livestock waste and in waste-treatment lagoons. The introduction of antibiotics into anaerobic lagoons commonly used for swine waste treatment has the potential for negative impacts on lagoon performance, which relies on a consortium of microbes ranging from fermentative microorganisms to methanogens. To address this concern, the effects of eight common veterinary antibiotics on anaerobic activity were studied. Anaerobic microcosms, prepared from freshly collected lagoon slurries, were amended with individual antibiotics at 10 mg/L for the initial screening study and at 1, 5, and 25 mg/L for the dose-response study. Monitored metabolic indicators included hydrogen, methane, and volatile fatty acid concentrations as well as chemical oxygen demand. The selected antibiotics significantly inhibited methane production relative to unamended controls, thus indicating that antibiotics at concentrations commonly found in swine lagoons can negatively impact anaerobic metabolism. Additionally, historical antibiotic usage seems to be a potential factor in affecting methane production. Specifically, less inhibition of methane production was noted in samples taken from the lagoon with a history of multiple-antibiotic use.

  20. Anaerobic metabolism of nitroaromatic compounds by sulfate-reducing and methanogenic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Boopathy, R. [Argonne National Lab., IL (United States); Kulpa, C.F. [Notre Dame Univ., IN (United States). Dept. of Biological Sciences

    1994-06-01

    Ecological observations suggest that sulfate-reducing and methanogenic bacteria might metabolize nitroaromatic compounds under anaerobic conditions if appropriate electron donors and electron acceptors are present in the environment, but this ability had not been demonstrated until recently. Most studies on the microbial metabolism of nitroaromatic compounds used aerobic microorganisms. In most cases no mineralization of nitroaromatics occurs, and only superficial modifications of the structures are reported. However, under anaerobic sulfate-reducing conditions, the nitroaromatic compounds reportedly undergo a series of reductions with the formation of amino compounds. For example, trinitrotoluene under sulfate-reducing conditions is reduced to triaminotoluene by the enzyme nitrite reductase, which is commonly found in many Desulfovibrio spp. The removal of ammonia from triaminotoluene is achieved by reductive deamination catalyzed by the enzyme reductive deaminase, with the production of ammonia and toluene. Some sulfate reducers can metabolize toluene to CO{sub 2}. Similar metabolic processes could be applied to other nitroaromatic compounds like nitrobenzene, nitrobenzoic acids, nitrophenols, and aniline. Many methanogenic bacteria can reduce nitroaromatic compounds to amino compounds. In this paper we review the anaerobic metabolic processes of nitroaromatic compounds under sulfate-reducing And methanogenic conditions.

  1. Anaerobic metabolism of nitroaromatic compounds by sulfate-reducing and methanogenic bacteria

    International Nuclear Information System (INIS)

    Boopathy, R.; Kulpa, C.F.

    1994-01-01

    Ecological observations suggest that sulfate-reducing and methanogenic bacteria might metabolize nitroaromatic compounds under anaerobic conditions if appropriate electron donors and electron acceptors are present in the environment, but this ability had not been demonstrated until recently. Most studies on the microbial metabolism of nitroaromatic compounds used aerobic microorganisms. In most cases no mineralization of nitroaromatics occurs, and only superficial modifications of the structures are reported. However, under anaerobic sulfate-reducing conditions, the nitroaromatic compounds reportedly undergo a series of reductions with the formation of amino compounds. For example, trinitrotoluene under sulfate-reducing conditions is reduced to triaminotoluene by the enzyme nitrite reductase, which is commonly found in many Desulfovibrio spp. The removal of ammonia from triaminotoluene is achieved by reductive deamination catalyzed by the enzyme reductive deaminase, with the production of ammonia and toluene. Some sulfate reducers can metabolize toluene to CO 2 . Similar metabolic processes could be applied to other nitroaromatic compounds like nitrobenzene, nitrobenzoic acids, nitrophenols, and aniline. Many methanogenic bacteria can reduce nitroaromatic compounds to amino compounds. In this paper we review the anaerobic metabolic processes of nitroaromatic compounds under sulfate-reducing And methanogenic conditions

  2. Thermophilic anaerobic acetate-utilizing methanogens and their metabolism

    DEFF Research Database (Denmark)

    Mladenovska, Zuzana

    Six strains of thermophilic anaerobic acetate-utilizing methanogens were isolated from different full-scale thermophilic biogas plants in China and Denmark. The strain isolated from the Chinese biogas plant was designated KN-6P and the isolates from the Danish full-scale biogas plants were......, utilizing the substrates acetate, methanol and methylamines but not hydrogen/carbon dioxide. Strain Methanosarcina sp. SO-2P was able to grow mixotrophically on methanol and hydrogen/carbon dioxide with methane formation from hydrogen and carbon dioxide occurring after methanol depletion. All six...... designated HG-1P, LVG-4P R1-1P, SO-2P and V-1P. The isolates were characterized morphologically and physiologically, and their immunological and phylogenetic relatedness to already known isolated strains were established. All isolated strains were identified as organisms belonging to genus Methanosarcina...

  3. Effects of Predation by Protists on Prokaryotic Community Function, Structure, and Diversity in Anaerobic Granular Sludge

    Science.gov (United States)

    Hirakata, Yuga; Oshiki, Mamoru; Kuroda, Kyohei; Hatamoto, Masashi; Kubota, Kengo; Yamaguchi, Takashi; Harada, Hideki; Araki, Nobuo

    2016-01-01

    Predation by protists is top-down pressure that regulates prokaryotic abundance, community function, structure, and diversity in natural and artificial ecosystems. Although the effects of predation by protists have been studied in aerobic ecosystems, they are poorly understood in anoxic environments. We herein studied the influence of predation by Metopus and Caenomorpha ciliates—ciliates frequently found in anoxic ecosystems—on prokaryotic community function, structure, and diversity. Metopus and Caenomorpha ciliates were cocultivated with prokaryotic assemblages (i.e., anaerobic granular sludge) in an up-flow anaerobic sludge blanket (UASB) reactor for 171 d. Predation by these ciliates increased the methanogenic activities of granular sludge, which constituted 155% of those found in a UASB reactor without the ciliates (i.e., control reactor). Sequencing of 16S rRNA gene amplicons using Illumina MiSeq revealed that the prokaryotic community in the UASB reactor with the ciliates was more diverse than that in the control reactor; 2,885–3,190 and 2,387–2,426 operational taxonomic units (>97% sequence similarities), respectively. The effects of predation by protists in anaerobic engineered systems have mostly been overlooked, and our results show that the influence of predation by protists needs to be examined and considered in the future for a better understanding of prokaryotic community structure and function. PMID:27431197

  4. Effects of Predation by Protists on Prokaryotic Community Function, Structure, and Diversity in Anaerobic Granular Sludge.

    Science.gov (United States)

    Hirakata, Yuga; Oshiki, Mamoru; Kuroda, Kyohei; Hatamoto, Masashi; Kubota, Kengo; Yamaguchi, Takashi; Harada, Hideki; Araki, Nobuo

    2016-09-29

    Predation by protists is top-down pressure that regulates prokaryotic abundance, community function, structure, and diversity in natural and artificial ecosystems. Although the effects of predation by protists have been studied in aerobic ecosystems, they are poorly understood in anoxic environments. We herein studied the influence of predation by Metopus and Caenomorpha ciliates-ciliates frequently found in anoxic ecosystems-on prokaryotic community function, structure, and diversity. Metopus and Caenomorpha ciliates were cocultivated with prokaryotic assemblages (i.e., anaerobic granular sludge) in an up-flow anaerobic sludge blanket (UASB) reactor for 171 d. Predation by these ciliates increased the methanogenic activities of granular sludge, which constituted 155% of those found in a UASB reactor without the ciliates (i.e., control reactor). Sequencing of 16S rRNA gene amplicons using Illumina MiSeq revealed that the prokaryotic community in the UASB reactor with the ciliates was more diverse than that in the control reactor; 2,885-3,190 and 2,387-2,426 operational taxonomic units (>97% sequence similarities), respectively. The effects of predation by protists in anaerobic engineered systems have mostly been overlooked, and our results show that the influence of predation by protists needs to be examined and considered in the future for a better understanding of prokaryotic community structure and function.

  5. Responses of anaerobic rumen fungal diversity (phylum Neocallimastigomycota) to changes in bovine diet.

    Science.gov (United States)

    Boots, B; Lillis, L; Clipson, N; Petrie, K; Kenny, D A; Boland, T M; Doyle, E

    2013-03-01

    Anaerobic rumen fungi (Neocallimastigales) play important roles in the breakdown of complex, cellulose-rich material. Subsequent decomposition products are utilized by other microbes, including methanogens. The aim of this study was to determine the effects of dietary changes on anaerobic rumen fungi diversity. Altered diets through increasing concentrate/forage (50 : 50 vs 90 : 10) ratios and/or the addition of 6% soya oil were offered to steers and the Neocallimastigales community was assessed by PCR-based fingerprinting with specific primers within the barcode region. Both a decrease in fibre content and the addition of 6% soya oil affected Neocallimastigales diversity within solid and liquid rumen phases. The addition of 6% soya oil decreased species richness. Assemblages were strongly affected by the addition of 6% soya oil, whereas unexpectedly, the fibre decrease had less effect. Differences in volatile fatty acid contents (acetate, propionate and butyrate) were significantly associated with changes in Neocallimastigales assemblages between the treatments. Diet clearly influences Neocallimastigales assemblages. The data are interpreted in terms of interactions with other microbial groups involved in fermentation processes within the rumen. Knowledge on the influence of diet on anaerobic fungi is necessary to understand changes in microbial processes occurring within the rumen as this may impact on other rumen processes such as methane production. © 2012 The Society for Applied Microbiology.

  6. Evolution of Molybdenum Nitrogenase during the Transition from Anaerobic to Aerobic Metabolism

    Science.gov (United States)

    Boyd, Eric S.; Costas, Amaya M. Garcia; Hamilton, Trinity L.; Mus, Florence

    2015-01-01

    ABSTRACT Molybdenum nitrogenase (Nif), which catalyzes the reduction of dinitrogen to ammonium, has modulated the availability of fixed nitrogen in the biosphere since early in Earth's history. Phylogenetic evidence indicates that oxygen (O2)-sensitive Nif emerged in an anaerobic archaeon and later diversified into an aerobic bacterium. Aerobic bacteria that fix N2 have adapted a number of strategies to protect Nif from inactivation by O2, including spatial and temporal segregation of Nif from O2 and respiratory consumption of O2. Here we report the complement of Nif-encoding genes in 189 diazotrophic genomes. We show that the evolution of Nif during the transition from anaerobic to aerobic metabolism was accompanied by both gene recruitment and loss, resulting in a substantial increase in the number of nif genes. While the observed increase in the number of nif genes and their phylogenetic distribution are strongly correlated with adaptation to utilize O2 in metabolism, the increase is not correlated with any of the known O2 protection mechanisms. Rather, gene recruitment appears to have been in response to selective pressure to optimize Nif synthesis to meet fixed N demands associated with aerobic productivity and to more efficiently regulate Nif under oxic conditions that favor protein turnover. Consistent with this hypothesis, the transition of Nif from anoxic to oxic environments is associated with a shift from posttranslational regulation in anaerobes to transcriptional regulation in obligate aerobes and facultative anaerobes. Given that fixed nitrogen typically limits ecosystem productivity, our observations further underscore the dynamic interplay between the evolution of Earth's oxygen, nitrogen, and carbon biogeochemical cycles. IMPORTANCE Molybdenum nitrogenase (Nif), which catalyzes the reduction of dinitrogen to ammonium, has modulated the availability of fixed nitrogen in the biosphere since early in Earth's history. Nif emerged in an anaerobe and

  7. Evolution of molybdenum nitrogenase during the transition from anaerobic to aerobic metabolism.

    Science.gov (United States)

    Boyd, Eric S; Costas, Amaya M Garcia; Hamilton, Trinity L; Mus, Florence; Peters, John W

    2015-05-01

    Molybdenum nitrogenase (Nif), which catalyzes the reduction of dinitrogen to ammonium, has modulated the availability of fixed nitrogen in the biosphere since early in Earth's history. Phylogenetic evidence indicates that oxygen (O2)-sensitive Nif emerged in an anaerobic archaeon and later diversified into an aerobic bacterium. Aerobic bacteria that fix N2 have adapted a number of strategies to protect Nif from inactivation by O2, including spatial and temporal segregation of Nif from O2 and respiratory consumption of O2. Here we report the complement of Nif-encoding genes in 189 diazotrophic genomes. We show that the evolution of Nif during the transition from anaerobic to aerobic metabolism was accompanied by both gene recruitment and loss, resulting in a substantial increase in the number of nif genes. While the observed increase in the number of nif genes and their phylogenetic distribution are strongly correlated with adaptation to utilize O2 in metabolism, the increase is not correlated with any of the known O2 protection mechanisms. Rather, gene recruitment appears to have been in response to selective pressure to optimize Nif synthesis to meet fixed N demands associated with aerobic productivity and to more efficiently regulate Nif under oxic conditions that favor protein turnover. Consistent with this hypothesis, the transition of Nif from anoxic to oxic environments is associated with a shift from posttranslational regulation in anaerobes to transcriptional regulation in obligate aerobes and facultative anaerobes. Given that fixed nitrogen typically limits ecosystem productivity, our observations further underscore the dynamic interplay between the evolution of Earth's oxygen, nitrogen, and carbon biogeochemical cycles. Molybdenum nitrogenase (Nif), which catalyzes the reduction of dinitrogen to ammonium, has modulated the availability of fixed nitrogen in the biosphere since early in Earth's history. Nif emerged in an anaerobe and later diversified into

  8. Partitioning the metabolic scope: the importance of anaerobic metabolism and implications for the oxygen- and capacity-limited thermal tolerance (OCLTT) hypothesis

    DEFF Research Database (Denmark)

    Ejbye-Ernst, Rasmus; Michaelsen, Thomas Y.; Tirsgaard, B.

    2016-01-01

    , the methodology rarely accounts for anaerobic metabolism within the MS. Using gilthead sea bream (Sparus aurata) and Trinidadian guppy (Poecilia reticulata), this study tested for trade-offs (i) between aerobic and anaerobic components of locomotor performance; and (ii) between the corresponding components...... of the MS. Data collection involved measuring oxygen consumption rate at increasing swimming speeds, using the gait transition from steady to unsteady (burst-assisted) swimming to detect the onset of anaerobic metabolism. Results provided evidence of the locomotor performance trade-off, but only in S...

  9. Microbial diversity and anaerobic hydrocarbon degradation potential in an oil-contaminated mangrove sediment.

    Science.gov (United States)

    Andrade, Luiza L; Leite, Deborah C A; Ferreira, Edir M; Ferreira, Lívia Q; Paula, Geraldo R; Maguire, Michael J; Hubert, Casey R J; Peixoto, Raquel S; Domingues, Regina M C P; Rosado, Alexandre S

    2012-08-30

    Mangrove forests are coastal wetlands that provide vital ecosystem services and serve as barriers against natural disasters like tsunamis, hurricanes and tropical storms. Mangroves harbour a large diversity of organisms, including microorganisms with important roles in nutrient cycling and availability. Due to tidal influence, mangroves are sites where crude oil from spills farther away can accumulate. The relationship between mangrove bacterial diversity and oil degradation in mangrove sediments remains poorly understood. Mangrove sediment was sampled from 0-5, 15-20 and 35-40 cm depth intervals from the Suruí River mangrove (Rio de Janeiro, Brazil), which has a history of oil contamination. DGGE fingerprinting for bamA, dsr and 16S rRNA encoding fragment genes, and qPCR analysis using dsr and 16S rRNA gene fragment revealed differences with sediment depth. Analysis of bacterial 16S rRNA gene diversity revealed changes with depth. DGGE for bamA and dsr genes shows that the anaerobic hydrocarbon-degrading community profile also changed between 5 and 15 cm depth, and is similar in the two deeper sediments, indicating that below 15 cm the anaerobic hydrocarbon-degrading community appears to be well established and homogeneous in this mangrove sediment. qPCR analysis revealed differences with sediment depth, with general bacterial abundance in the top layer (0-5 cm) being greater than in both deeper sediment layers (15-20 and 35-40 cm), which were similar to each other.

  10. Electron acceptors for anaerobic oxidation of methane drive microbial community structure and diversity in mud volcanoes.

    Science.gov (United States)

    Ren, Ge; Ma, Anzhou; Zhang, Yanfen; Deng, Ye; Zheng, Guodong; Zhuang, Xuliang; Zhuang, Guoqiang; Fortin, Danielle

    2018-04-06

    Mud volcanoes (MVs) emit globally significant quantities of methane into the atmosphere, however, methane cycling in such environments is not yet fully understood, as the roles of microbes and their associated biogeochemical processes have been largely overlooked. Here, we used data from high-throughput sequencing of microbial 16S rRNA gene amplicons from six MVs in the Junggar Basin in northwest China to quantify patterns of diversity and characterize the community structure of archaea and bacteria. We found anaerobic methanotrophs and diverse sulfate- and iron-reducing microbes in all of the samples, and the diversity of both archaeal and bacterial communities was strongly linked to the concentrations of sulfate, iron and nitrate, which could act as electron acceptors in anaerobic oxidation of methane (AOM). The impacts of sulfate/iron/nitrate on AOM in the MVs were verified by microcosm experiments. Further, two representative MVs were selected to explore the microbial interactions based on phylogenetic molecular ecological networks. The sites showed distinct network structures, key species and microbial interactions, with more complex and numerous linkages between methane-cycling microbes and their partners being observed in the iron/sulfate-rich MV. These findings suggest that electron acceptors are important factors driving the structure of microbial communities in these methane-rich environments. © 2018 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  11. Performance of thermophilic anaerobic digesters using inoculum mixes with enhanced methanogenic diversity

    KAUST Repository

    Ghanimeh, Sophia

    2017-05-30

    BACKGROUND Reportedly, various mixes of seeds were quasi-randomly selected to startup anaerobic digesters. In contrast, this study examines the impact of inoculating thermophilic anaerobic digesters with a designed mix of non-acclimated seeds based on their methanogen composition, using Quantitative Polymerase Chain Reaction (QPCR) of 16S rRNA gene, to achieve high abundance and diversity of methanogens. RESULTS Based on QPCR results, two seed mixes were selected to inoculate two anaerobic digesters: digester (A) was inoculated with a control seed consisting of digestate, manure, and activated sludge; and digester (B) was inoculated with a further methanogen-enriched seed consisting of the control seed with added compost and leachate. Both seed combinations yielded a balanced microflora that is able to achieve a successful startup. However, upon reaching steady state, digester B exhibited lower propionate levels, resulting in lower VFA concentration and increased buffering capacity, indicating greater stability. Acetotrophs and hydrogenotrophs were dominated by Methanosarcinaceae and Methanobacteriales, respectively, in both digesters, exhibiting an average ratio of 66-to-34% in A and 76-to-24% in B during steady state. CONCLUSION The inoculation strategy in digester B resulted in improved stability, lower propionate concentration and 10% higher relative abundance of acetotrophs.

  12. CO2-dependent metabolic modulation in red blood cells stored under anaerobic conditions

    Science.gov (United States)

    Dumont, Larry J.; D'Alessandro, Angelo; Szczepiorkowski, Zbigniew M.; Yoshida, Tatsuro

    2015-01-01

    Background Anaerobic RBC storage reduces oxidative damage, maintains ATP & 2,3-diphosphoglycerate (DPG) levels and has superior 24hr recovery at 6weeks compared to standard storage. This study will determine if removal of CO2 during O2 depletion by gas exchange may affect RBC during anaerobic storage. Methods This is a matched 3 arm study (n=14): control, O2&CO2 depleted with Ar (AN), O2 depleted with 95%Ar/5%CO2 (AN[CO2]). RBC in additives AS-3 or OFAS3 were evenly divided into 3 bags, and anaerobic conditions were established by gas exchange. Bags were stored 1-6°C in closed chambers under anaerobic conditions or ambient air, sampled weekly for up to 9weeks for a panel of in vitro tests. A full metabolomics screening was conducted for the first 4 weeks of storage. Results Purging with Ar (AN) results in alkalization of the RBC and increased glucose consumption. The addition of 5%CO2 to the purging gas prevented CO2 loss with an equivalent starting and final pH and lactate to control bags (p>0.5, days0-21). ATP levels are higher in AN[CO2] (p<0.0001). DPG was maintained beyond 2 weeks in the AN arm (p<0.0001). Surprisingly, DPG was lost at the same rate in both control and AN[CO2] arms (p=0.6). Conclusion Maintenance of ATP in the AN[CO2] arm demonstrates that ATP production is not solely a function of the pH effect on glycolysis. CO2 in anaerobic storage prevented the maintenance of DPG, and DPG production appears to be pH dependent. CO2 as well as O2 depletion provides metabolic advantage for stored RBC. PMID:26477888

  13. CO2 -dependent metabolic modulation in red blood cells stored under anaerobic conditions.

    Science.gov (United States)

    Dumont, Larry J; D'Alessandro, Angelo; Szczepiorkowski, Zbigniew M; Yoshida, Tatsuro

    2016-02-01

    Anaerobic red blood cell (RBC) storage reduces oxidative damage, maintains adenosine triphosphate (ATP) and 2,3-diphosphoglycerate (DPG) levels, and has superior 24-hour recovery at 6 weeks compared to standard storage. This study will determine if removal of CO2 during O2 depletion by gas exchange may affect RBCs during anaerobic storage. This is a matched three-arm study (n = 14): control, O2 and CO2 depleted with Ar (AN), and O2 depleted with 95%Ar/5%CO2 (AN[CO2 ]). RBCs in additives AS-3 or OFAS-3 were evenly divided into three bags, and anaerobic conditions were established by gas exchange. Bags were stored at 1 to 6°C in closed chambers under anaerobic conditions or ambient air, sampled weekly for up to 9 weeks for a panel of in vitro tests. A full metabolomics screening was conducted for the first 4 weeks of storage. Purging with Ar (AN) results in alkalization of the RBC and increased glucose consumption. The addition of 5% CO2 to the purging gas prevented CO2 loss with an equivalent starting and final pH and lactate to control bags (p > 0.5, Days 0-21). ATP levels are higher in AN[CO2 ] (p < 0.0001). DPG was maintained beyond 2 weeks in the AN arm (p < 0.0001). Surprisingly, DPG was lost at the same rate in both control and AN[CO2 ] arms (p = 0.6). Maintenance of ATP in the AN[CO2 ] arm demonstrates that ATP production is not solely a function of the pH effect on glycolysis. CO2 in anaerobic storage prevented the maintenance of DPG, and DPG production appears to be pH dependent. CO2 as well as O2 depletion provides metabolic advantage for stored RBCs. © 2015 AABB.

  14. Anaerobic carbon monoxide metabolism by Pleomorphomonas carboxyditropha sp. nov., a new mesophilic hydrogenogenic carboxydotroph.

    Science.gov (United States)

    Esquivel-Elizondo, Sofia; Maldonado, Juan; Krajmalnik-Brown, Rosa

    2018-06-01

    Carbon monoxide (CO)-metabolism and phenotypic and phylogenetic characterization of a novel anaerobic, mesophilic and hydrogenogenic carboxydotroph are reported. Strain SVCO-16 was isolated from anaerobic sludge and grows autotrophically and mixotrophically with CO. The genes cooS and cooF, coding for a CO dehydrogenase complex, and genes similar to hycE2, encoding a CO-induced hydrogenase, were present in its genome. The isolate produces H2 and CO2 from CO, and acetate and formate from organic substrates. Based on the 16S rRNA sequence, it is an Alphaproteobacterium most closely related to the genus Pleomorphomonas (98.9%-99.2% sequence identity). Comparison with other previously characterized Pleomorphomonas showed that P. diazotrophica and P. oryzae do not metabolize CO, and P. diazotrophica does not grow anaerobically with organic substrates. Average nucleotide identity values between strain SVCO-16 and P. diazotrophica, P. oryzae or P. koreensis were 86.66 ± 0.21%. These values are below the boundary to define species (95%-96%). Digital DNA-DNA hybridization estimates between strain SVCO-16 and reference strains were also below the 70% threshold for species delineation: 29.1%-34.5%. Based on the differences in CO metabolism, genome analyses and cellular fatty acid composition, the isolate should be classified into the genus Pleomorphomonas as a representative of a novel species, Pleomorphomonas carboxyditropha. The type strain of Pleomorphomonas carboxyditropha is SVCO-16T (strain deposit numbers, DSM 106132T and TSD-119T).

  15. In vitro metabolism of radiolabeled carbohydrates by protective cecal anaerobic bacteria.

    Science.gov (United States)

    Hume, M E; Beier, R C; Hinton, A; Scanlan, C M; Corrier, D E; Peterson, D V; DeLoach, J R

    1993-12-01

    Cecal anaerobic bacteria from adult broilers were cultured in media containing .25% glucose or .25% lactose. Media also contained either [14C]-labeled lactose, glucose, galactose, or lactic acid as metabolic tracers. Cultures were analyzed at 4, 8, and 12 h for pH, radiolabeled and unlabeled volatile fatty acids, and lactic acid. The pH values of cultures containing .25% lactose were significantly (P galactose, lactose > glucose. The volatile fatty acids in which radiolabel was most concentrated were acetic acid, propionic acid, or butyric acid.

  16. Quantitative Metaproteomics Highlight the Metabolic Contributions of Uncultured Phylotypes in a Thermophilic Anaerobic Digester.

    Science.gov (United States)

    Hagen, Live H; Frank, Jeremy A; Zamanzadeh, Mirzaman; Eijsink, Vincent G H; Pope, Phillip B; Horn, Svein J; Arntzen, Magnus Ø

    2017-01-15

    In this study, we used multiple meta-omic approaches to characterize the microbial community and the active metabolic pathways of a stable industrial biogas reactor with food waste as the dominant feedstock, operating at thermophilic temperatures (60°C) and elevated levels of free ammonia (367 mg/liter NH 3 -N). The microbial community was strongly dominated (76% of all 16S rRNA amplicon sequences) by populations closely related to the proteolytic bacterium Coprothermobacter proteolyticus. Multiple Coprothermobacter-affiliated strains were detected, introducing an additional level of complexity seldom explored in biogas studies. Genome reconstructions provided metabolic insight into the microbes that performed biomass deconstruction and fermentation, including the deeply branching phyla Dictyoglomi and Planctomycetes and the candidate phylum "Atribacteria" These biomass degraders were complemented by a synergistic network of microorganisms that convert key fermentation intermediates (fatty acids) via syntrophic interactions with hydrogenotrophic methanogens to ultimately produce methane. Interpretation of the proteomics data also suggested activity of a Methanosaeta phylotype acclimatized to high ammonia levels. In particular, we report multiple novel phylotypes proposed as syntrophic acetate oxidizers, which also exert expression of enzymes needed for both the Wood-Ljungdahl pathway and β-oxidation of fatty acids to acetyl coenzyme A. Such an arrangement differs from known syntrophic oxidizing bacteria and presents an interesting hypothesis for future studies. Collectively, these findings provide increased insight into active metabolic roles of uncultured phylotypes and presents new synergistic relationships, both of which may contribute to the stability of the biogas reactor. Biogas production through anaerobic digestion of organic waste provides an attractive source of renewable energy and a sustainable waste management strategy. A comprehensive understanding

  17. [Effect of the medium redox potential on the growth and metabolism of anaerobic bacteria].

    Science.gov (United States)

    Vasilian, A; Trchunian, A

    2008-01-01

    Based on the available literature data on a decrease in the redox potential of medium to low negative values and a decrease in pH during the growth of sugar-fermenting anaerobic bacteria, it was concluded that these processes cannot be described by the theory of redox potential. A theory was developed according to which the regulation of bacterial metabolism is accomplished through changes in the redox potential. The theory considers the redox potential as a factor determining the growth of anaerobic bacteria, which is regulated by oxidizers and reducers. The assumption is put forward that, under anaerobic conditions, bacteria are sensitive to changes in the redox potential and have a redox taxis. The effect of the redox potential on the transport of protons and other substances through membranes and the activity of membrane-bound enzymes, including the proton F1-F0-ATPase, whose mechanisms of action involve changes in the proton conductance of the membrane, the generation of proton-driving force, and dithiol-disulfide transitions in proteins was studied.

  18. Summer investigations into the metabolic diversity of the microbial world. Progress report, May 5, 1992--April 30, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Breznak, J.; Dworkin, M.

    1993-05-17

    The philosophy of the course described here is to underscore the essence of microbiology which is diversity>: diversity of morphology and cellular development, behavior, and metabolic and physiological functions. Emphasis is on microbes other than those customarily covered in conventional microbiology courses and includes: the archaebacteria, extremophiles, and array of obligate anaerobes, various phototrophs, and those microbes exhibiting complex developmental cycles. Also included are microbes carrying out a variety of transformations of organic and inorganic compounds, as well as those which normally occur in symbiotic association with other microbes or with higher forms of life.

  19. Microbial diversity and anaerobic hydrocarbon degradation potential in an oil-contaminated mangrove sediment

    Directory of Open Access Journals (Sweden)

    Andrade Luiza L

    2012-08-01

    Full Text Available Abstract Background Mangrove forests are coastal wetlands that provide vital ecosystem services and serve as barriers against natural disasters like tsunamis, hurricanes and tropical storms. Mangroves harbour a large diversity of organisms, including microorganisms with important roles in nutrient cycling and availability. Due to tidal influence, mangroves are sites where crude oil from spills farther away can accumulate. The relationship between mangrove bacterial diversity and oil degradation in mangrove sediments remains poorly understood. Results Mangrove sediment was sampled from 0–5, 15–20 and 35–40 cm depth intervals from the Suruí River mangrove (Rio de Janeiro, Brazil, which has a history of oil contamination. DGGE fingerprinting for bamA, dsr and 16S rRNA encoding fragment genes, and qPCR analysis using dsr and 16S rRNA gene fragment revealed differences with sediment depth. Conclusions Analysis of bacterial 16S rRNA gene diversity revealed changes with depth. DGGE for bamA and dsr genes shows that the anaerobic hydrocarbon-degrading community profile also changed between 5 and 15 cm depth, and is similar in the two deeper sediments, indicating that below 15 cm the anaerobic hydrocarbon-degrading community appears to be well established and homogeneous in this mangrove sediment. qPCR analysis revealed differences with sediment depth, with general bacterial abundance in the top layer (0–5 cm being greater than in both deeper sediment layers (15–20 and 35–40 cm, which were similar to each other.

  20. 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

  1. Effect of gamma irradiation on the microstructure and post-mortem anaerobic metabolism of bovine muscle

    International Nuclear Information System (INIS)

    Yook, H.-S.; Lee, J.-W.; Lee, K.-H.; Kim, M.-K.; Song, C.-W.; Byun, M.-W.

    2001-01-01

    Experiments were performed to study the effect of gamma irradiation on morphological properties and post-mortem metabolism in bovine M. sternomandibularis with special reference to ultrastructure, shear force, pH and ATP breakdown. The shortening of sarcomere was not observed in gamma-irradiated muscle, however, the disappearance of M-line and of A- and I-bands was perceptible. During cold storage, the destruction of muscle bundles was faster in the gamma-irradiated muscle than in the non-irradiated with a dose-dependent manner. The same is true for the post mortem pH drop and ATP breakdown. So, experimental results confirmed that the anaerobic metabolism and morphological properties are noticeably affected by gamma irradiation in beef

  2. Acidosis, but Not Alkalosis, Affects Anaerobic Metabolism and Performance in a 4-km Time Trial.

    Science.gov (United States)

    Correia-Oliveira, Carlos Rafaell; Lopes-Silva, João Paulo; Bertuzzi, Romulo; McConell, Glenn K; Bishop, David John; Lima-Silva, Adriano Eduardo; Kiss, Maria Augusta Peduti Dal'molin

    2017-09-01

    This study aimed to determine the effect of preexercise metabolic acidosis and alkalosis on power output (PO) and aerobic and anaerobic energy expenditure during a 4-km cycling time trial (TT). Eleven recreationally trained cyclists (V˙O2peak 54.1 ± 9.3 mL·kg·min) performed a 4-km TT 100 min after ingesting in a double-blind matter 0.15 g·kg of body mass of ammonium chloride (NH4Cl, acidosis), 0.3 g·kg of sodium bicarbonate (NaHCO3, alkalosis), or 0.15 g·kg of CaCO3 (placebo). A preliminary study (n = 7) was conducted to establish the optimal doses to promote the desirable preexercise blood pH alterations without gastrointestinal distress. Data for PO, aerobic and anaerobic energy expenditure, and blood and respiratory parameters were averaged for each 1 km and compared between conditions using two-way repeated-measures ANOVA (condition and distance factors). Gastrointestinal discomfort was analyzed qualitatively. Compared with placebo (pH 7.37 ± 0.02, [HCO3]: 27.5 ± 2.6 mmol·L), the NaHCO3 ingestion resulted in a preexercise blood alkalosis (pH +0.06 ± 0.04, [HCO3]: +4.4 ± 2.0 mmol·L, P 0.05). Minimal gastrointestinal distress was noted in all conditions. Preexercise acidosis, but not alkalosis, affects anaerobic metabolism and PO during a 4-km cycling TT.

  3. Processes of malate catabolism during the anaerobic metabolism of grape berries

    International Nuclear Information System (INIS)

    Flanzy, C.; Andre, P.; Buret, M.; Chambroy, Y.; Garcia, P.

    1976-01-01

    In order to precise malate fate during the anaerobic metabolism of grape, malate- 3 - 14 C was injected into Carignan berries kept in darkness at 35 0 C under carbon dioxide atmosphere. The injection of labelled malate was effected in presence or not of non-labelled oxalate which inhibits malic enzyme (EC I.I.I.40). The analyses of the samples fixed after 3 and 7 days anaerobiosis concerned the titration of various substrates, organic acids, amino-acids and glycolysis products, and the measuring of the NADP + -malic enzyme (EC I.I.I.40) and malate dehydrogenase (EC I.I.I.40). Radioactivity is mainly observed in ethanol, amino-butyrate the non-separated group glycerate-shikimate and succinate. Malic enzyme acts in the first sequence of a process leading from malate to ethanol. Alanin synthesis seems to be stimulated in presence of oxalate. The results obtained and some hypotheses presented in the literature induce to suggest a utilization scheme for malate in the anaerobic metabolism of grape [fr

  4. Hydrodynamic chronoamperometry for probing kinetics of anaerobic microbial metabolism--case study of Faecalibacterium prausnitzii.

    Science.gov (United States)

    Prévoteau, Antonin; Geirnaert, Annelies; Arends, Jan B A; Lannebère, Sylvain; Van de Wiele, Tom; Rabaey, Korneel

    2015-07-01

    Monitoring in vitro the metabolic activity of microorganisms aids bioprocesses and enables better understanding of microbial metabolism. Redox mediators can be used for this purpose via different electrochemical techniques that are either complex or only provide non-continuous data. Hydrodynamic chronoamperometry using a rotating disc electrode (RDE) can alleviate these issues but was seldom used and is poorly characterized. The kinetics of Faecalibacterium prausnitzii A2-165, a beneficial gut microbe, were determined using a RDE with riboflavin as redox probe. This butyrate producer anaerobically ferments glucose and reduces riboflavin whose continuous monitoring on a RDE provided highly accurate kinetic measurements of its metabolism, even at low cell densities. The metabolic reaction rate increased linearly over a broad range of cell concentrations (9 × 10(4) to 5 × 10(7) cells.mL(-1)). Apparent Michaelis-Menten kinetics was observed with respect to riboflavin (KM = 6 μM; kcat = 5.3 × 10(5) s(-1), at 37 °C) and glucose (KM = 6 μM; kcat = 2.4 × 10(5) s(-1)). The short temporal resolution allows continuous monitoring of fast cellular events such as kinetics inhibition with butyrate. Furthermore, we detected for the first time riboflavin reduction by another potential probiotic, Butyricicoccus pullicaecorum. The ability of the RDE for fast, accurate, simple and continuous measurements makes it an ad hoc tool for assessing bioprocesses at high resolution.

  5. Performance of thermophilic anaerobic digesters using inoculum mixes with enhanced methanogenic diversity

    KAUST Repository

    Ghanimeh, Sophia; El-Fadel, Mutasem; Saikaly, Pascal

    2017-01-01

    Reportedly, various mixes of seeds were quasi-randomly selected to startup anaerobic digesters. In contrast, this study examines the impact of inoculating thermophilic anaerobic digesters with a designed mix of non-acclimated seeds based

  6. Probing the redox metabolism in the strictly anaerobic, extremely thermophilic, hydrogen-producing Caldicellulosiruptor saccharolyticus using amperometry

    DEFF Research Database (Denmark)

    Kostesha, Natalie; Willquist, Karin; Emnéus, Jenny

    2011-01-01

    Changes in the redox metabolism in the anaerobic, extremely thermophilic, hydrogen-forming bacterium Caldicellulosiruptor saccharolyticus were probed for the first time in vivo using mediated amperometry with ferricyanide as a thermotolerant external mediator. Clear differences in the intracellul...... in the intracellular electron flow and to probe redox enzyme properties of a strictly anaerobic thermophile in vivo.......Changes in the redox metabolism in the anaerobic, extremely thermophilic, hydrogen-forming bacterium Caldicellulosiruptor saccharolyticus were probed for the first time in vivo using mediated amperometry with ferricyanide as a thermotolerant external mediator. Clear differences in the intracellular...... the NADH-dependent lactate dehydrogenase, upon which more NADH was directed to membrane-associated enzymes for ferricyanide reduction, leading to a higher electrochemical signal. The method is noninvasive and the results presented here demonstrate that this method can be used to accurately detect changes...

  7. Effects of lactone, ketone, and phenolic compounds on methane production and metabolic intermediates during anaerobic digestion.

    Science.gov (United States)

    Wikandari, Rachma; Sari, Noor Kartika; A'yun, Qurrotul; Millati, Ria; Cahyanto, Muhammad Nur; Niklasson, Claes; Taherzadeh, Mohammad J

    2015-02-01

    Fruit waste is a potential feedstock for biogas production. However, the presence of fruit flavors that have antimicrobial activity is a challenge for biogas production. Lactones, ketones, and phenolic compounds are among the several groups of fruit flavors that are present in many fruits. This work aimed to investigate the effects of two lactones, i.e., γ-hexalactone and γ-decalactone; two ketones, i.e., furaneol and mesifurane; and two phenolic compounds, i.e., quercetin and epicatechin on anaerobic digestion with a focus on methane production, biogas composition, and metabolic intermediates. Anaerobic digestion was performed in a batch glass digester incubated at 55 °C for 30 days. The flavor compounds were added at concentrations of 0.05, 0.5, and 5 g/L. The results show that the addition of γ-decalactone, quercetin, and epicathechin in the range of 0.5-5 g/L reduced the methane production by 50 % (MIC50). Methane content was reduced by 90 % with the addition of 5 g/L of γ-decalactone, quercetin, and epicathechin. Accumulation of acetic acid, together with an increase in carbon dioxide production, was observed. On the contrary, γ-hexalactone, furaneol, and mesifurane increased the methane production by 83-132 % at a concentration of 5 g/L.

  8. In situ detection of anaerobic alkane metabolites in subsurface environments

    Directory of Open Access Journals (Sweden)

    Lisa eGieg

    2013-06-01

    Full Text Available Alkanes comprise a substantial fraction of crude oil and refined fuels. As such, they are prevalent within deep subsurface fossil fuel deposits and in shallow subsurface environments such as aquifers that are contaminated with hydrocarbons. These environments are typically anaerobic, and host diverse microbial communities that can potentially use alkanes as substrates. Anaerobic alkane biodegradation has been reported to occur under nitrate-reducing, sulfate-reducing, and methanogenic conditions. Elucidating the pathways of anaerobic alkane metabolism has been of interest in order to understand how microbes can be used to remediate contaminated sites. Alkane activation primarily occurs by addition to fumarate, yielding alkylsuccinates, unique anaerobic metabolites that can be used to indicate in situ anaerobic alkane metabolism. These metabolites have been detected in hydrocarbon-contaminated shallow aquifers, offering strong evidence for intrinsic anaerobic bioremediation. Recently, studies have also revealed that alkylsuccinates are present in oil and coal seam production waters, indicating that anaerobic microbial communities can utilize alkanes in these deeper subsurface environments. In many crude oil reservoirs, the in situ anaerobic metabolism of hydrocarbons such as alkanes may be contibuting to modern-day detrimental effects such as oilfield souring, or may lead to more benefical technologies such as enhanced energy recovery from mature oilfields. In this review, we briefly describe the key metabolic pathways for anaerobic alkane (including n-alkanes, isoalkanes, and cyclic alkanes metabolism and highlight several field reports wherein alkylsuccinates have provided evidence for anaerobic in situ alkane metabolism in shallow and deep subsurface environments.

  9. Diversity and distribution of planktonic anaerobic ammonium-oxidizing bacteria in the Dongjiang River, China.

    Science.gov (United States)

    Sun, Wei; Xia, Chunyu; Xu, Meiying; Guo, Jun; Wang, Aijie; Sun, Guoping

    2014-12-01

    Anaerobic ammonium-oxidizing (anammox) process has recently been recognized as an important pathway for removing fixed nitrogen (N) from aquatic ecosystems. Anammox organisms are widely distributed in freshwater environments. However, little is known about their presence in the water column of riverine ecosystems. Here, the existence of a diverse anammox community was revealed in the water column of the Dongjiang River by analyzing 16S rRNA and hydrazine oxidation (hzo) genes of anammox bacteria. Phylogenetic analyses of hzo genes showed that Candidatus Jettenia related clades of anammox bacteria were dominant in the river, suggesting the ecological microniche distinction from freshwater/estuary and marine anammox bacteria with Ca. Brocadia and Kuenenia genera mainly detected in freshwater/estuary ecosystems, and Ca. Scalindua genus mainly detected in marine ecosystems. The abundance and diversity of anammox bacteria along the river were both significantly correlated with concentrations of NH4(+)-N based on Pearson and partial correlation analyses. Redundancy analyses showed the contents of NH4(+)-N, NO3(-)-N and the ratio of NH4(+)-N to NO2(-)-N significantly influenced the spatial distributions of anammox bacteria in the water column of the Dongjiang River. These results expanded our understanding of the distribution and potential roles of anammox bacteria in the water column of the river ecosystem. Copyright © 2014 Elsevier GmbH. All rights reserved.

  10. Correlation exploration of metabolic and genomic diversity in rice

    Directory of Open Access Journals (Sweden)

    Shinozaki Kazuo

    2009-12-01

    Full Text Available Abstract Background It is essential to elucidate the relationship between metabolic and genomic diversity to understand the genetic regulatory networks associated with the changing metabolo-phenotype among natural variation and/or populations. Recent innovations in metabolomics technologies allow us to grasp the comprehensive features of the metabolome. Metabolite quantitative trait analysis is a key approach for the identification of genetic loci involved in metabolite variation using segregated populations. Although several attempts have been made to find correlative relationships between genetic and metabolic diversity among natural populations in various organisms, it is still unclear whether it is possible to discover such correlations between each metabolite and the polymorphisms found at each chromosomal location. To assess the correlative relationship between the metabolic and genomic diversity found in rice accessions, we compared the distance matrices for these two "omics" patterns in the rice accessions. Results We selected 18 accessions from the world rice collection based on their population structure. To determine the genomic diversity of the rice genome, we genotyped 128 restriction fragment length polymorphism (RFLP markers to calculate the genetic distance among the accessions. To identify the variations in the metabolic fingerprint, a soluble extract from the seed grain of each accession was analyzed with one dimensional 1H-nuclear magnetic resonance (NMR. We found no correlation between global metabolic diversity and the phylogenetic relationships among the rice accessions (rs = 0.14 by analyzing the distance matrices (calculated from the pattern of the metabolic fingerprint in the 4.29- to 0.71-ppm 1H chemical shift and the genetic distance on the basis of the RFLP markers. However, local correlation analysis between the distance matrices (derived from each 0.04-ppm integral region of the 1H chemical shift against genetic

  11. Cancer and Exercise: Warburg Hypothesis, Tumour Metabolism and High-Intensity Anaerobic Exercise.

    Science.gov (United States)

    Hofmann, Peter

    2018-01-31

    There is ample evidence that regular moderate to vigorous aerobic physical activity is related to a reduced risk for various forms of cancer to suggest a causal relationship. Exercise is associated with positive changes in fitness, body composition, and physical functioning as well as in patient-reported outcomes such as fatigue, sleep quality, or health-related quality of life. Emerging evidence indicates that exercise may also be directly linked to the control of tumour biology through direct effects on tumour-intrinsic factors. Beside a multitude of effects of exercise on the human body, one underscored effect of exercise training is to target the specific metabolism of tumour cells, namely the Warburg-type highly glycolytic metabolism. Tumour metabolism as well as the tumour⁻host interaction may be selectively influenced by single bouts as well as regularly applied exercise, dependent on exercise intensity, duration, frequency and mode. High-intensity anaerobic exercise was shown to inhibit glycolysis and some studies in animals showed that effects on tumour growth might be stronger compared with moderate-intensity aerobic exercise. High-intensity exercise was shown to be safe in patients; however, it has to be applied carefully with an individualized prescription of exercise.

  12. Anaerobic C1 metabolism of the O-methyl-14C-labeled substituent of vanillate

    International Nuclear Information System (INIS)

    Frazer, A.C.; Young, L.Y.

    1986-01-01

    The O-methyl substituents of aromatic compounds constitute a C 1 growth substrate for a number of taxonomically diverse anaerobic acetogens. In this study, strain TH-001, an O-demethylating obligate anaerobe, was chosen to represent this physiological group, and the carbon flow when cells were grown on O-methyl substituents as a C 1 substrate was determined by 14 C radiotracer techniques. O-[methyl- 14 C]vanillate (4-hydroxy-3-methoxy-benzoate) was used as the labeled C 1 substrate. The data showed that for every O-methyl carbon converted to [ 14 C]acetate, two were oxidized to 14 CO 2 . Quantitation of the carbon recovered in the two products, acetate and CO 2 , indicated that acetate was formed in part by the fixation of unlabeled CO 2 . The specific activity of 14 C in acetate was 70% of that in the O-methyl substrate, suggesting that only one carbon of acetate was derived from the O-methyl group. Thus, it is postulated that the carboxyl carbon of the product acetate is derived from CO 2 and the methyl carbon is derived from the O-methyl substituent of vanillate

  13. Hydrodynamic chronoamperometry for probing kinetics of anaerobic microbial metabolism - case study of Faecalibacterium prausnitzii

    Science.gov (United States)

    Prévoteau, Antonin; Geirnaert, Annelies; Arends, Jan B. A.; Lannebère, Sylvain; van de Wiele, Tom; Rabaey, Korneel

    2015-07-01

    Monitoring in vitro the metabolic activity of microorganisms aids bioprocesses and enables better understanding of microbial metabolism. Redox mediators can be used for this purpose via different electrochemical techniques that are either complex or only provide non-continuous data. Hydrodynamic chronoamperometry using a rotating disc electrode (RDE) can alleviate these issues but was seldom used and is poorly characterized. The kinetics of Faecalibacterium prausnitzii A2-165, a beneficial gut microbe, were determined using a RDE with riboflavin as redox probe. This butyrate producer anaerobically ferments glucose and reduces riboflavin whose continuous monitoring on a RDE provided highly accurate kinetic measurements of its metabolism, even at low cell densities. The metabolic reaction rate increased linearly over a broad range of cell concentrations (9 × 104 to 5 × 107 cells.mL-1). Apparent Michaelis-Menten kinetics was observed with respect to riboflavin (KM = 6 μM kcat = 5.3×105 s-1, at 37 °C) and glucose (KM = 6 μM kcat = 2.4 × 105 s-1). The short temporal resolution allows continuous monitoring of fast cellular events such as kinetics inhibition with butyrate. Furthermore, we detected for the first time riboflavin reduction by another potential probiotic, Butyricicoccus pullicaecorum. The ability of the RDE for fast, accurate, simple and continuous measurements makes it an ad hoc tool for assessing bioprocesses at high resolution.

  14. Carbohydrate management, anaerobic metabolism, and adenosine levels in the armoured catfish, Liposarcus pardalis (castelnau), during hypoxia.

    Science.gov (United States)

    Maccormack, Tyson James; Lewis, Johanne Mari; Almeida-Val, Vera Maria Fonseca; Val, Adalberto Luis; Driedzic, William Robert

    2006-04-01

    The armoured catfish, Liposarcus pardalis, tolerates severe hypoxia at high temperatures. Although this species can breathe air, it also has a strong anaerobic metabolism. We assessed tissue to plasma glucose ratios and glycogen and lactate in a number of tissues under "natural" pond hypoxia, and severe aquarium hypoxia without aerial respiration. Armour lactate content and adenosine in brain and heart were also investigated. During normoxia, tissue to plasma glucose ratios in gill, brain, and heart were close to one. Hypoxia increased plasma glucose and decreased tissue to plasma ratios to less than one, suggesting glucose phosphorylation is activated more than uptake. High normoxic white muscle glucose relative to plasma suggests gluconeogenesis or active glucose uptake. Excess muscle glucose may serve as a metabolic reserve since hypoxia decreased muscle to plasma glucose ratios. Mild pond hypoxia changed glucose management in the absence of lactate accumulation. Lactate was elevated in all tissues except armour following aquarium hypoxia; however, confinement in aquaria increased armour lactate, even under normoxia. A stress-associated acidosis may contribute to armour lactate sequestration. High plasma lactate levels were associated with brain adenosine accumulation. An increase in heart adenosine was triggered by confinement in aquaria, although not by hypoxia alone.

  15. Kinetics of butyrate, acetate, and hydrogen metabolism in a thermophilic, anaerobic, butyrate-degrading triculture.

    Science.gov (United States)

    Ahring, B K; Westermann, P

    1987-02-01

    Kinetics of butyrate, acetate, and hydrogen metabolism were determined with butyrate-limited, chemostat-grown tricultures of a thermophilic butyrate-utilizing bacterium together with Methanobacterium thermoautotrophicum and the TAM organism, a thermophilic acetate-utilizing methanogenic rod. Kinetic parameters were determined from progress curves fitted to the integrated form of the Michaelis-Menten equation. The apparent half-saturation constants, K(m), for butyrate, acetate, and dissolved hydrogen were 76 muM, 0.4 mM, and 8.5 muM, respectively. Butyrate and hydrogen were metabolized to a concentration of less than 1 muM, whereas acetate uptake usually ceased at a concentration of 25 to 75 muM, indicating a threshold level for acetate uptake. No significant differences in K(m) values for butyrate degradation were found between chemostat- and batch-grown tricultures, although the maximum growth rate was somewhat higher in the batch cultures in which the medium was supplemented with yeast extract. Acetate utilization was found to be the rate-limiting reaction for complete degradation of butyrate to methane and carbon dioxide in continuous culture. Increasing the dilution rate resulted in a gradual accumulation of acetate. The results explain the low concentrations of butyrate and hydrogen normally found during anaerobic digestion and the observation that acetate is the first volatile fatty acid to accumulate upon a decrease in retention time or increase in organic loading of a digestor.

  16. Anaerobic choline metabolism in microcompartments promotes growth and swarming of Proteus mirabilis.

    Science.gov (United States)

    Jameson, Eleanor; Fu, Tiantian; Brown, Ian R; Paszkiewicz, Konrad; Purdy, Kevin J; Frank, Stefanie; Chen, Yin

    2016-09-01

    Gammaproteobacteria are important gut microbes but only persist at low levels in the healthy gut. The ecology of Gammaproteobacteria in the gut environment is poorly understood. Here, we demonstrate that choline is an important growth substrate for representatives of Gammaproteobacteria. Using Proteus mirabilis as a model, we investigate the role of choline metabolism and demonstrate that the cutC gene, encoding a choline-trimethylamine lyase, is essential for choline degradation to trimethylamine by targeted mutagenesis of cutC and subsequent complementation experiments. Proteus mirabilis can rapidly utilize choline to enhance growth rate and cell yield in broth culture. Importantly, choline also enhances swarming-associated colony expansion of P. mirabilis under anaerobic conditions on a solid surface. Comparative transcriptomics demonstrated that choline not only induces choline-trimethylamine lyase but also genes encoding shell proteins for the formation of bacterial microcompartments. Subsequent analyses by transmission electron microscopy confirmed the presence of such novel microcompartments in cells cultivated in liquid broth and hyper-flagellated swarmer cells from solid medium. Together, our study reveals choline metabolism as an adaptation strategy for P. mirabilis and contributes to better understand the ecology of this bacterium in health and disease. © 2015 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  17. Microbiological Diversity of the Anaerobic Sludge During Treatment of Venezuelan Oilfield Produced Waters

    Directory of Open Access Journals (Sweden)

    Cajacuri María Patricia

    2013-06-01

    Full Text Available In the present investigation the microbial abundances in the granular sludge of two upflow anaerobic sludge blanket reactors (UASB were compared: the first one fed with production waters of light oil (31.1-39.0° API, from the zuliana region (Venezuela (APP and the second one with glucose. To this respect, the populations of glucose fermenting bacteria (BFG, acetogenic bacteria (BAC, metanogens (MET, sulfatereducing bacteria (BSR, nitrate-reducing bacteria (BNRand heterotrophic bacteria were monitored, using selective culture media. The microbial density was correlated with physicochemical parameters: pH, total alkalinity, COD, SO4 =, NO3-, as well as with the percentages of CH4, CO2 and N2in the biogas. The results exhibit significant differences between the microbial diversity of both reactors, with a proportion of BFG > BSR > MET > BAC > BNR for the glucose reactor and of MET > BNR > BAC > BSR > BFG for the APP. The abundance of bacteria in the glucose reactor was in the order of 108, whereas in the APP reactor was of 105, which ensues from the organic and mineral composition of effluents. The results presented in this study reach evidences on the population dynamics in sludge of UASB reactors, during the treatment of oilfield produced waters.

  18. Regulation and function of versatile aerobic and anaerobic respiratory metabolism in Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Hiroyuki eArai

    2011-05-01

    Full Text Available Pseudomonas aeruginosa is a ubiquitously distributed opportunistic pathogen that inhabits soil and water as well as animal-, human-, and plant-host-associated environments. The ubiquity would be attributed to its very versatile energy metabolism. P. aeruginosa has a highly branched respiratory chain terminated by multiple terminal oxidases and denitrification enzymes. Five terminal oxidases for aerobic respiration have been identified in the P. aeruginosa cells. Three of them, the cbb3-1 oxidase, the cbb3-2 oxidase, and the aa3 oxidase, are cytochrome c oxidases and the other two, the bo3 oxidase and the cyanide-insensitive oxidase, are quinol oxidases. Each oxidase has a specific affinity for oxygen, efficiency of energy coupling, and tolerance to various stresses such as cyanide and reactive nitrogen species. These terminal oxidases are used differentially according to the environmental conditions. P. aeruginosa also has a complete set of the denitrification enzymes that reduce nitrate to molecular nitrogen via nitrite, nitric oxide (NO, and nitrous oxide. These nitrogen oxides function as alternative electron acceptors and enable P. aeruginosa to grow under anaerobic conditions. One of the denitrification enzymes, NO reductase, is also expected to function for detoxification of NO produced by the host immune defense system. The control of the expression of these aerobic and anaerobic respiratory enzymes would contribute to the adaptation of P. aeruginosa to a wide range of environmental conditions including in the infected hosts. Characteristics of these respiratory enzymes and the regulatory system that controls the expression of the respiratory genes in the P. aeruginosa cells are overviewed in this article.

  19. Microbial diversity in a full-scale anaerobic reactor treating high ...

    African Journals Online (AJOL)

    Microbial characteristics in the up-flow anaerobic sludge blanket reactor (UASB) of a full-scale high concentration cassava alcohol wastewater plant capable of anaerobic hydrocarbon removal were analyzed using cultivation-independent molecular methods. Forty-five bacterial operational taxonomic units (OTUs) and 24 ...

  20. In vivo imaging and tracking of host-microbiota interactions via metabolic labeling of gut anaerobic bacteria

    Science.gov (United States)

    Geva-Zatorsky, Naama; Alvarez, David; Hudak, Jason E.; Reading, Nicola C.; Erturk-Hasdemir, Deniz; Dasgupta, Suryasarathi; von Andrian, Ulrich H.; Kasper, Dennis L.

    2015-01-01

    The intestine is densely populated by anaerobic commensal bacteria. These microorganisms shape immune system development, but our understanding of host–commensal interactions is hampered by a lack of tools for studying the anaerobic intestinal environment. We applied metabolic oligosaccharide engineering and bioorthogonal click-chemistry to label various commensal anaerobes, including Bacteroides fragilis, a common and immunologically important commensal. We studied the dissemination of B. fragilis following acute peritonitis, and characterized the interactions of the intact microbe and its polysaccharide components in myeloid and B cell lineages. The distribution and colonization of labeled B. fragilis along the intestine can be assessed, as well as niche competition following coadministration of multiple species of the microbiota. Nine additional anaerobic commensals (both gram-negative and gram-positive) from three phyla common in the gut—Bacteroidetes, Firmicutes, and Proteobacteria—and five families and one aerobic pathogen (Staphylococcus aureus) were also fluorescently labeled. This strategy permits visualization of the anaerobic microbial niche by various methods, including intravital two-photon microscopy and non-invasive whole-body imaging, and an approach to study microbial colonization and host–microbe interactions in real-time. PMID:26280120

  1. Co-existence of Anaerobic Ammonium Oxidation Bacteria and Denitrifying Anaerobic Methane Oxidation Bacteria in Sewage Sludge: Community Diversity and Seasonal Dynamics.

    Science.gov (United States)

    Xu, Sai; Lu, Wenjing; Mustafa, Muhammad Farooq; Caicedo, Luis Miguel; Guo, Hanwen; Fu, Xindi; Wang, Hongtao

    2017-11-01

    Anaerobic ammonium oxidation (ANAMMOX) and denitrifying anaerobic methane oxidation (DAMO) have been recently discovered as relevant processes in the carbon and nitrogen cycles of wastewater treatment plants. In this study, the seasonal dynamics of ANAMMOX and DAMO bacterial community structures and their abundance in sewage sludge collected from wastewater treatment plants were analysed. Results indicated that ANAMMOX and DAMO bacteria co-existed in sewage sludge in different seasons and their abundance was positively correlated (P bacteria in autumn and winter indicated that these seasons were the preferred time to favour the growth of ANAMMOX and DAMO bacteria. The community structure of ANNAMOX and DAMO bacteria could also shift with seasonal changes. The "Candidatus Brocadia" genus of ANAMMOX bacteria was mainly recovered in spring and summer, and an unknown cluster was primarily detected in autumn and winter. Similar patterns of seasonal variation in the community structure of DAMO bacteria were also observed. Group B was the dominant in spring and summer, whereas in autumn and winter, group A and group B presented almost the same proportion. The redundancy analysis revealed that pH and nitrate were the most significant factors affecting community structures of these two groups (P < 0.01). This study reported the diversity of ANAMMOX and DAMO in wastewater treatment plants that may be the basis for new nitrogen removal technologies.

  2. The effect of isoproterenol on some aspects of the anaerobic metabolism of carbohydrates in mouse submandibular gland.

    Science.gov (United States)

    Sassaki, K T; Nicolau, J

    1982-01-01

    1. The effect of isoproterenol, a beta-adrenergic drug, on some aspects of the anaerobic metabolism of carbohydrates in the submandibular salivary glands of mice was studied. 2. Alterations in enzymatic activities and in the concentrations of some metabolites were observed in groups of animals killed at various times after the stimulation. 3. The potential capacity of the pentose phosphate cycle was greater than that of glycolysis up to 20 hr after the stimulation.

  3. Complete genome of Ignavibacterium album, a metabolically versatile, flagellated, facultative anaerobe from the phylum Chlorobi

    Directory of Open Access Journals (Sweden)

    Zhenfeng eLiu

    2012-05-01

    Full Text Available Prior to the recent discovery of Ignavibacterium album (I. album, anaerobic photoautotrophic green sulfur bacteria (GSB were the only cultivated members of the bacterial phylum Chlorobi. In contrast to GSB, sequence analysis of the 3.7-Mbp genome of I. album shows that this recently described member of the phylum Chlorobi is a chemoheterotroph with a versatile metabolism. I. album lacks genes for photosynthesis and sulfur oxidation but has a full set of genes for flagella and chemotaxis. The occurrence of genes for multiple electron transfer complexes suggests that I. album is capable of organoheterotrophy under both oxic and anoxic conditions. The occurrence of genes encoding enzymes for CO2 fixation as well as other enzymes of the reductive TCA cycle suggests that mixotrophy may be possible under certain growth conditions. However, known biosynthetic pathways for several amino acids are incomplete; this suggests that I. album is dependent upon on exogenous sources of these metabolites or employs novel biosynthetic pathways. Comparisons of I. album and other members of the phylum Chlorobi suggest that the physiology of the ancestors of this phylum might have been quite different from that of modern GSB.

  4. Anaerobic organic acid metabolism of Candida zemplinina in comparison with Saccharomyces wine yeasts.

    Science.gov (United States)

    Magyar, Ildikó; Nyitrai-Sárdy, Diána; Leskó, Annamária; Pomázi, Andrea; Kállay, Miklós

    2014-05-16

    Organic acid production under oxygen-limited conditions has been thoroughly studied in the Saccharomyces species, but practically never investigated in Candida zemplinina, which seems to be an acidogenic species under oxidative laboratory conditions. In this study, several strains of C. zemplinina were tested for organic acid metabolism, in comparison with Saccharomyces cerevisiae, Saccharomyces uvarum and Candida stellata, under fermentative conditions. Only C. stellata produced significantly higher acidity in simple minimal media (SM) with low sugar content and two different nitrogen sources (ammonia or glutamic acid) at low level. However, the acid profile differed largely between the Saccharomyces and Candida species and showed inverse types of N-dependence in some cases. Succinic acid production was strongly enhanced on glutamic acid in Saccharomyces species, but not in Candida species. 2-oxoglutarate production was strongly supported on ammonium nitrogen in Candida species, but remained low in Saccharomyces. Candida species, C. stellata in particular, produced more pyruvic acid regardless of N-sources. From the results, we concluded that the anaerobic organic acid metabolisms of C. zemplinina and C. stellata are different from each other and also from that of the Saccharomyces species. In the formation of succinic acid, the oxidative pathway from glutamic acid seems to play little or no role in C. zemplinina. The reductive branch of the TCA cycle, however, produces acidic intermediates (malic, fumaric, and succinic acid) in a level comparable with the production of the Saccharomyces species. An unidentified organic acid, which was produced on glutamic acid only by the Candida species, needs further investigation. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Microbial diversity and metabolic networks in acid mine drainage habitats

    Directory of Open Access Journals (Sweden)

    Celia eMendez-Garcia

    2015-05-01

    Full Text Available Acid mine drainage (AMD emplacements are low-complexity natural systems. Low-pH conditions appear to be the main factor underlying the limited diversity of the microbial populations thriving in these environments, although temperature, ionic composition, total organic carbon and dissolved oxygen are also considered to significantly influence their microbial life. This natural reduction in diversity driven by extreme conditions was reflected in several studies on the microbial populations inhabiting the various micro-environments present in such ecosystems. Early studies based on the physiology of the autochthonous microbiota and the growing success of omics technologies have enabled a better understanding of microbial ecology and function in low-pH mine outflows; however, complementary omics-derived data should be included to completely describe their microbial ecology. Furthermore, recent updates on the distribution of eukaryotes and ultra-micro-archaea demand their inclusion in the microbial characterisation of AMD systems. In this review, we present a complete overview of the bacterial, archaeal (including ultra-micro-archaeal and eukaryotic diversity in these ecosystems and include a thorough depiction of the metabolism and element cycling in AMD habitats. We also review different metabolic network structures at the organismal level, which is necessary to disentangle the role of each member of the AMD communities described thus far.

  6. Anaerobic metabolism at thermal extremes: a metabolomic test of the oxygen limitation hypothesis in an aquatic insect.

    Science.gov (United States)

    Verberk, W C E P; Sommer, U; Davidson, R L; Viant, M R

    2013-10-01

    Thermal limits in ectotherms may arise through a mismatch between supply and demand of oxygen. At higher temperatures, the ability of their cardiac and ventilatory activities to supply oxygen becomes insufficient to meet their elevated oxygen demand. Consequently, higher levels of oxygen in the environment are predicted to enhance tolerance of heat, whereas reductions in oxygen are expected to reduce thermal limits. Here, we extend previous research on thermal limits and oxygen limitation in aquatic insect larvae and directly test the hypothesis of increased anaerobic metabolism and lower energy status at thermal extremes. We quantified metabolite profiles in stonefly nymphs under varying temperatures and oxygen levels. Under normoxia, the concept of oxygen limitation applies to the insects studied. Shifts in the metabolome of heat-stressed stonefly nymphs clearly indicate the onset of anaerobic metabolism (e.g., accumulation of lactate, acetate, and alanine), a perturbation of the tricarboxylic acid cycle (e.g., accumulation of succinate and malate), and a decrease in energy status (e.g., ATP), with corresponding decreases in their ability to survive heat stress. These shifts were more pronounced under hypoxic conditions, and negated by hyperoxia, which also improved heat tolerance. Perturbations of metabolic pathways in response to either heat stress or hypoxia were found to be somewhat similar but not identical. Under hypoxia, energy status was greatly compromised at thermal extremes, but energy shortage and anaerobic metabolism could not be conclusively identified as the sole cause underlying thermal limits under hyperoxia. Metabolomics proved useful for suggesting a range of possible mechanisms to explore in future investigations, such as the involvement of leaking membranes or free radicals. In doing so, metabolomics provided a more complete picture of changes in metabolism under hypoxia and heat stress.

  7. Directed Evolution Reveals Unexpected Epistatic Interactions That Alter Metabolic Regulation and Enable Anaerobic Xylose Use by Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Trey K Sato

    2016-10-01

    Full Text Available The inability of native Saccharomyces cerevisiae to convert xylose from plant biomass into biofuels remains a major challenge for the production of renewable bioenergy. Despite extensive knowledge of the regulatory networks controlling carbon metabolism in yeast, little is known about how to reprogram S. cerevisiae to ferment xylose at rates comparable to glucose. Here we combined genome sequencing, proteomic profiling, and metabolomic analyses to identify and characterize the responsible mutations in a series of evolved strains capable of metabolizing xylose aerobically or anaerobically. We report that rapid xylose conversion by engineered and evolved S. cerevisiae strains depends upon epistatic interactions among genes encoding a xylose reductase (GRE3, a component of MAP Kinase (MAPK signaling (HOG1, a regulator of Protein Kinase A (PKA signaling (IRA2, and a scaffolding protein for mitochondrial iron-sulfur (Fe-S cluster biogenesis (ISU1. Interestingly, the mutation in IRA2 only impacted anaerobic xylose consumption and required the loss of ISU1 function, indicating a previously unknown connection between PKA signaling, Fe-S cluster biogenesis, and anaerobiosis. Proteomic and metabolomic comparisons revealed that the xylose-metabolizing mutant strains exhibit altered metabolic pathways relative to the parental strain when grown in xylose. Further analyses revealed that interacting mutations in HOG1 and ISU1 unexpectedly elevated mitochondrial respiratory proteins and enabled rapid aerobic respiration of xylose and other non-fermentable carbon substrates. Our findings suggest a surprising connection between Fe-S cluster biogenesis and signaling that facilitates aerobic respiration and anaerobic fermentation of xylose, underscoring how much remains unknown about the eukaryotic signaling systems that regulate carbon metabolism.

  8. Directed Evolution Reveals Unexpected Epistatic Interactions That Alter Metabolic Regulation and Enable Anaerobic Xylose Use by Saccharomyces cerevisiae.

    Science.gov (United States)

    Sato, Trey K; Tremaine, Mary; Parreiras, Lucas S; Hebert, Alexander S; Myers, Kevin S; Higbee, Alan J; Sardi, Maria; McIlwain, Sean J; Ong, Irene M; Breuer, Rebecca J; Avanasi Narasimhan, Ragothaman; McGee, Mick A; Dickinson, Quinn; La Reau, Alex; Xie, Dan; Tian, Mingyuan; Reed, Jennifer L; Zhang, Yaoping; Coon, Joshua J; Hittinger, Chris Todd; Gasch, Audrey P; Landick, Robert

    2016-10-01

    The inability of native Saccharomyces cerevisiae to convert xylose from plant biomass into biofuels remains a major challenge for the production of renewable bioenergy. Despite extensive knowledge of the regulatory networks controlling carbon metabolism in yeast, little is known about how to reprogram S. cerevisiae to ferment xylose at rates comparable to glucose. Here we combined genome sequencing, proteomic profiling, and metabolomic analyses to identify and characterize the responsible mutations in a series of evolved strains capable of metabolizing xylose aerobically or anaerobically. We report that rapid xylose conversion by engineered and evolved S. cerevisiae strains depends upon epistatic interactions among genes encoding a xylose reductase (GRE3), a component of MAP Kinase (MAPK) signaling (HOG1), a regulator of Protein Kinase A (PKA) signaling (IRA2), and a scaffolding protein for mitochondrial iron-sulfur (Fe-S) cluster biogenesis (ISU1). Interestingly, the mutation in IRA2 only impacted anaerobic xylose consumption and required the loss of ISU1 function, indicating a previously unknown connection between PKA signaling, Fe-S cluster biogenesis, and anaerobiosis. Proteomic and metabolomic comparisons revealed that the xylose-metabolizing mutant strains exhibit altered metabolic pathways relative to the parental strain when grown in xylose. Further analyses revealed that interacting mutations in HOG1 and ISU1 unexpectedly elevated mitochondrial respiratory proteins and enabled rapid aerobic respiration of xylose and other non-fermentable carbon substrates. Our findings suggest a surprising connection between Fe-S cluster biogenesis and signaling that facilitates aerobic respiration and anaerobic fermentation of xylose, underscoring how much remains unknown about the eukaryotic signaling systems that regulate carbon metabolism.

  9. Identification of metabolically active methanogens in anaerobic digester by DNA Stable-Isotope Probing using 13C-acetate

    Directory of Open Access Journals (Sweden)

    V. Gowdaman

    2015-04-01

    Full Text Available Anaerobic digestion is gaining enormous attention due to the ability to covert organic wastes into biogas, an alternative sustainable energy. Methanogenic community plays a significant role in biogas production and also for proficient functioning of the anaerobic digester. Therefore, this study was carried out to investigate the methanogen diversity of a food waste anaerobic digester. After endogenous respiration, the digester samples were supplemented with isotopes of acetate to enrich methanogen population, and were analyzed using DNA-SIP (Stable-Isotope Probing. Following separation and fractionation of heavy (13C and light (12C DNA, PCR amplification was carried out using archaeal 16S rRNA gene followed by DGGE analysis. Sequencing of the prominent DGGE bands revealed the dominance of Methanocorpusculum labreanum species belonging to hydrogenotrophic Methanomicrobiales, which can produce methane in the presence of H2/CO2 and requires acetate for its growth. This is the first instance where Methanocorpusculum labreanum is being reported as a dominant species in an anaerobic digester operative on food waste.

  10. Anaerobic hydrocarbon and fatty acid metabolism by syntrophic bacteria and their impact on carbon steel corrosion

    Directory of Open Access Journals (Sweden)

    Christopher Neil Lyles

    2014-04-01

    Full Text Available The microbial metabolism of hydrocarbons is increasingly associated with the corrosion of carbon steel in sulfate-rich marine waters. However, how such transformations influence metal biocorrosion in the absence of an electron acceptor is not fully recognized. We grew a marine alkane-utilizing, sulfate-reducing bacterium, Desulfoglaeba alkanexedens, with either sulfate or Methanospirillum hungatei as electron acceptors, and tested the ability of the cultures to catalyze metal corrosion. Axenically, D. alkanexedens had a higher instantaneous corrosion rate and produced more pits in carbon steel coupons than when the same organism was grown in syntrophic co-culture with the methanogen. Since anaerobic hydrocarbon biodegradation pathways converge on fatty acid intermediates, the corrosive ability of a known fatty acid-oxidizing syntrophic bacterium, Syntrophus aciditrophicus was compared when grown in pure culture or in co-culture with a H2-utilizing sulfate-reducing bacterium (Desulfovibrio sp., strain G11 or a methanogen (M. hungatei. The instantaneous corrosion rates in the cultures were not substantially different, but the syntrophic, sulfate-reducing co-culture produced more pits in coupons than other combinations of microorganisms. Lactate-grown cultures of strain G11 had higher instantaneous corrosion rates and coupon pitting compared to the same organism cultured with hydrogen as an electron donor. Thus, if sulfate is available as an electron acceptor, the same microbial assemblages produce sulfide and low molecular weight organic acids that exacerbated biocorrosion. Despite these trends, a surprisingly high degree of variation was encountered with the corrosion assessments. Differences in biomass, initial substrate concentration, rates of microbial activity or the degree of end product formation did not account for the variations. We are forced to ascribe such differences to the metallurgical properties of the coupons.

  11. Anaerobic hydrocarbon and fatty acid metabolism by syntrophic bacteria and their impact on carbon steel corrosion.

    Science.gov (United States)

    Lyles, Christopher N; Le, Huynh M; Beasley, William Howard; McInerney, Michael J; Suflita, Joseph M

    2014-01-01

    The microbial metabolism of hydrocarbons is increasingly associated with the corrosion of carbon steel in sulfate-rich marine waters. However, how such transformations influence metal biocorrosion in the absence of an electron acceptor is not fully recognized. We grew a marine alkane-utilizing, sulfate-reducing bacterium, Desulfoglaeba alkanexedens, with either sulfate or Methanospirillum hungatei as electron acceptors, and tested the ability of the cultures to catalyze metal corrosion. Axenically, D. alkanexedens had a higher instantaneous corrosion rate and produced more pits in carbon steel coupons than when the same organism was grown in syntrophic co-culture with the methanogen. Since anaerobic hydrocarbon biodegradation pathways converge on fatty acid intermediates, the corrosive ability of a known fatty acid-oxidizing syntrophic bacterium, Syntrophus aciditrophicus was compared when grown in pure culture or in co-culture with a H2-utilizing sulfate-reducing bacterium (Desulfovibrio sp., strain G11) or a methanogen (M. hungatei). The instantaneous corrosion rates in the cultures were not substantially different, but the syntrophic, sulfate-reducing co-culture produced more pits in coupons than other combinations of microorganisms. Lactate-grown cultures of strain G11 had higher instantaneous corrosion rates and coupon pitting compared to the same organism cultured with hydrogen as an electron donor. Thus, if sulfate is available as an electron acceptor, the same microbial assemblages produce sulfide and low molecular weight organic acids that exacerbated biocorrosion. Despite these trends, a surprisingly high degree of variation was encountered with the corrosion assessments. Differences in biomass, initial substrate concentration, rates of microbial activity or the degree of end product formation did not account for the variations. We are forced to ascribe such differences to the metallurgical properties of the coupons.

  12. A review on the bioenergetics of anaerobic microbial metabolism close to the thermodynamic limits and its implications for digestion applications.

    Science.gov (United States)

    Leng, Ling; Yang, Peixian; Singh, Shubham; Zhuang, Huichuan; Xu, Linji; Chen, Wen-Hsing; Dolfing, Jan; Li, Dong; Zhang, Yan; Zeng, Huiping; Chu, Wei; Lee, Po-Heng

    2018-01-01

    The exploration of the energetics of anaerobic digestion systems can reveal how microorganisms cooperate efficiently for cell growth and methane production, especially under low-substrate conditions. The establishment of a thermodynamically interdependent partnership, called anaerobic syntrophy, allows unfavorable reactions to proceed. Interspecies electron transfer and the concentrations of electron carriers are crucial for maintaining this mutualistic activity. This critical review summarizes the functional microorganisms and syntroph partners, particularly in the metabolic pathways and energy conservation of syntrophs. The kinetics and thermodynamics of propionate degradation to methane, reversibility of the acetate oxidation process, and estimation of microbial growth are summarized. The various routes of interspecies electron transfer, reverse electron transfer, and Poly-β-hydroxyalkanoate formation in the syntrophic community are also reviewed. Finally, promising and critical directions of future research are proposed. Fundamental insight in the activities and interactions involved in AD systems could serve as a guidance for engineered systems optimization and upgrade. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Strain-Level Diversity of Secondary Metabolism in Streptomyces albus

    Science.gov (United States)

    Seipke, Ryan F.

    2015-01-01

    Streptomyces spp. are robust producers of medicinally-, industrially- and agriculturally-important small molecules. Increased resistance to antibacterial agents and the lack of new antibiotics in the pipeline have led to a renaissance in natural product discovery. This endeavor has benefited from inexpensive high quality DNA sequencing technology, which has generated more than 140 genome sequences for taxonomic type strains and environmental Streptomyces spp. isolates. Many of the sequenced streptomycetes belong to the same species. For instance, Streptomyces albus has been isolated from diverse environmental niches and seven strains have been sequenced, consequently this species has been sequenced more than any other streptomycete, allowing valuable analyses of strain-level diversity in secondary metabolism. Bioinformatics analyses identified a total of 48 unique biosynthetic gene clusters harboured by Streptomyces albus strains. Eighteen of these gene clusters specify the core secondary metabolome of the species. Fourteen of the gene clusters are contained by one or more strain and are considered auxiliary, while 16 of the gene clusters encode the production of putative strain-specific secondary metabolites. Analysis of Streptomyces albus strains suggests that each strain of a Streptomyces species likely harbours at least one strain-specific biosynthetic gene cluster. Importantly, this implies that deep sequencing of a species will not exhaust gene cluster diversity and will continue to yield novelty. PMID:25635820

  14. Enhanced volatile fatty acids production from anaerobic fermentation of food waste: A mini-review focusing on acidogenic metabolic pathways.

    Science.gov (United States)

    Zhou, Miaomiao; Yan, Binghua; Wong, Jonathan W C; Zhang, Yang

    2018-01-01

    Recently, efficient disposal of food waste (FW) with potential resource recovery has attracted great attentions. Due to its easily biodegradable nature, rich nutrient availability and high moisture content, FW is regarded as favorable substrate for anaerobic digestion (AD). Both waste disposal and energy recovery can be fulfilled during AD of FW. Volatile fatty acids (VFAs) which are the products of the first-two stages of AD, are widely applied in chemical industry as platform chemicals recently. Concentration and distribution of VFAs is the result of acidogenic metabolic pathways, which can be affected by the micro-environment (e.g. pH) in the digester. Hence, the clear elucidation of the acidogenic metabolic pathways is essential for optimization of acidogenic process for efficient product recovery. This review summarizes major acidogenic metabolic pathways and regulating strategies for enhancing VFAs recovery during acidogenic fermentation of FW. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Anaerobes in Industrial- and Environmental Biotechnology.

    Science.gov (United States)

    Hatti-Kaul, Rajni; Mattiasson, Bo

    Anaerobic microorganisms present in diverse ecological niches employ alternative strategies for energy conservation in the absence of oxygen which enables them to play a key role in maintaining the global cycles of carbon, nitrogen, and sulfur, and the breakdown of persistent compounds. Thereby they become useful tools in industrial and environmental biotechnology. Although anaerobes have been relatively neglected in comparison to their aerobic counterparts, with increasing knowledge about their diversity and metabolic potential and the development of genetic tools and process technologies to utilize them, we now see a rapid expansion of their applications in the society. This chapter summarizes some of the developments in the use of anaerobes as tools for biomass valorization, in production of energy carriers and chemicals, wastewater treatment, and the strong potential in soil remediation. The ability of several autotrophic anaerobes to reduce carbon dioxide is attracting growing attention as a means for developing a platform for conversion of waste gases to chemicals, materials, and biofuels.

  16. Diversity, metabolic properties and arsenic mobilization potential of indigenous bacteria in arsenic contaminated groundwater of West Bengal, India.

    Science.gov (United States)

    Paul, Dhiraj; Kazy, Sufia K; Gupta, Ashok K; Pal, Taraknath; Sar, Pinaki

    2015-01-01

    Arsenic (As) mobilization in alluvial aquifers is caused by a complex interplay of hydro-geo-microbiological activities. Nevertheless, diversity and biogeochemical significance of indigenous bacteria in Bengal Delta Plain are not well documented. We have deciphered bacterial community compositions and metabolic properties in As contaminated groundwater of West Bengal to define their role in As mobilization. Groundwater samples showed characteristic high As, low organic carbon and reducing property. Culture-independent and -dependent analyses revealed presence of diverse, yet near consistent community composition mostly represented by genera Pseudomonas, Flavobacterium, Brevundimonas, Polaromonas, Rhodococcus, Methyloversatilis and Methylotenera. Along with As-resistance and -reductase activities, abilities to metabolize a wide range carbon substrates including long chain and polyaromatic hydrocarbons and HCO3, As3+ as electron donor and As5+/Fe3+ as terminal electron acceptor during anaerobic growth were frequently observed within the cultivable bacteria. Genes encoding cytosolic As5+ reductase (arsC) and As3+ efflux/transporter [arsB and acr3(2)] were found to be more abundant than the dissimilatory As5+ reductase gene arrA. The observed metabolic characteristics showed a good agreement with the same derived from phylogenetic lineages of constituent populations. Selected bacterial strains incubated anaerobically over 300 days using natural orange sand of Pleistocene aquifer showed release of soluble As mostly as As3+ along with several other elements (Al, Fe, Mn, K, etc.). Together with the production of oxalic acid within the biotic microcosms, change in sediment composition and mineralogy indicated dissolution of orange sand coupled with As/Fe reduction. Presence of arsC gene, As5+ reductase activity and oxalic acid production by the bacteria were found to be closely related to their ability to mobilize sediment bound As. Overall observations suggest that

  17. Microbial Diversity in Sulfate-Reducing Marine Sediment Enrichment Cultures Associated with Anaerobic Biotransformation of Coastal Stockpiled Phosphogypsum (Sfax, Tunisia

    Directory of Open Access Journals (Sweden)

    Hana Zouch

    2017-08-01

    Full Text Available Anaerobic biotechnology using sulfate-reducing bacteria (SRB is a promising alternative for reducing long-term stockpiling of phosphogypsum (PG, an acidic (pH ~3 by-product of the phosphate fertilizer industries containing high amounts of sulfate. The main objective of this study was to evaluate, for the first time, the diversity and ability of anaerobic marine microorganisms to convert sulfate from PG into sulfide, in order to look for marine SRB of biotechnological interest. A series of sulfate-reducing enrichment cultures were performed using different electron donors (i.e., acetate, formate, or lactate and sulfate sources (i.e., sodium sulfate or PG as electron acceptors. Significant sulfide production was observed from enrichment cultures inoculated with marine sediments, collected near the effluent discharge point of a Tunisian fertilizer industry (Sfax, Tunisia. Sulfate sources impacted sulfide production rates from marine sediments as well as the diversity of SRB species belonging to Deltaproteobacteria. When PG was used as sulfate source, Desulfovibrio species dominated microbial communities of marine sediments, while Desulfobacter species were mainly detected using sodium sulfate. Sulfide production was also affected depending on the electron donor used, with the highest production obtained using formate. In contrast, low sulfide production (acetate-containing cultures was associated with an increase in the population of Firmicutes. These results suggested that marine Desulfovibrio species, to be further isolated, are potential candidates for bioremediation of PG by immobilizing metals and metalloids thanks to sulfide production by these SRB.

  18. Pathways and bioenergetics of anaerobic carbon monoxide fermentation

    NARCIS (Netherlands)

    Diender, Martijn; Stams, Fons; Machado de Sousa, Diana

    2015-01-01

    Carbon monoxide can act as a substrate for different modes of fermentative anaerobic metabolism. The trait of utilizing CO is spread among a diverse group of microorganisms, including members of bacteria as well as archaea. Over the last decade this metabolism has gained interest due to the

  19. Genetic diversity of b-glucuronidase activity among 14 strains of the dominant human gut anaerobe Ruminococcus gnavus

    Directory of Open Access Journals (Sweden)

    Diane Beaud

    2006-01-01

    Full Text Available Bacterial beta-glucuronidase activity in the gut increases the enterohepatic circulation of toxic compounds and plays a major role in the etiology of colon cancer. Previously, we had found that the gus gene, which codes for beta-glucuronidase in a dominant anaerobic species of the gut microbiota, Ruminococcus gnavus strain E1, is transcribed as part of an operon that includes three ORFs that code for beta-glucoside permeases of the phosphotransferase systems. This genetic organization had never been described. We have now compared beta-glucuronidase activity and the genetic environment of the gus gene in 14 strains of Ruminococcus gnavus.We found that five out of the seven glucuronidase-positive R. gnavus strains possessed another glucuronidase gene different from the gusA operon of R. gnavus E1. This dominant commensal intestinal species appears to have a high degree of genetic diversity in the genes that control beta-glucuronidase activity.

  20. A model‐driven quantitative metabolomics analysis of aerobic and anaerobic metabolism in E. coli K‐12 MG1655 that is biochemically and thermodynamically consistent

    DEFF Research Database (Denmark)

    McCloskey, Douglas; Gangoiti, Jon A.; King, Zachary A.

    2014-01-01

    in metabolomes between anaerobic and aerobic growth of Escherichia coli. Constraint‐based modeling was utilized to deduce a target list of compounds for downstream method development. An analytical and experimental methodology was developed and tailored to the compound chemistry and growth conditions of interest....... This included the construction of a rapid sampling apparatus for use with anaerobic cultures. The resulting genome‐scale data sets for anaerobic and aerobic growth were validated by comparison to previous small‐scale studies comparing growth of E. coli under the same conditions. The metabolomics data were......‐oxidation pathway for synthesis of fatty acids. This analysis also identified enzyme promiscuity for the pykA gene, that is critical for anaerobic growth, and which has not been previously incorporated into metabolic models of E coli. Biotechnol....

  1. Anaerobic catabolism of aromatic compounds: a genetic and genomic view.

    Science.gov (United States)

    Carmona, Manuel; Zamarro, María Teresa; Blázquez, Blas; Durante-Rodríguez, Gonzalo; Juárez, Javier F; Valderrama, J Andrés; Barragán, María J L; García, José Luis; Díaz, Eduardo

    2009-03-01

    Aromatic compounds belong to one of the most widely distributed classes of organic compounds in nature, and a significant number of xenobiotics belong to this family of compounds. Since many habitats containing large amounts of aromatic compounds are often anoxic, the anaerobic catabolism of aromatic compounds by microorganisms becomes crucial in biogeochemical cycles and in the sustainable development of the biosphere. The mineralization of aromatic compounds by facultative or obligate anaerobic bacteria can be coupled to anaerobic respiration with a variety of electron acceptors as well as to fermentation and anoxygenic photosynthesis. Since the redox potential of the electron-accepting system dictates the degradative strategy, there is wide biochemical diversity among anaerobic aromatic degraders. However, the genetic determinants of all these processes and the mechanisms involved in their regulation are much less studied. This review focuses on the recent findings that standard molecular biology approaches together with new high-throughput technologies (e.g., genome sequencing, transcriptomics, proteomics, and metagenomics) have provided regarding the genetics, regulation, ecophysiology, and evolution of anaerobic aromatic degradation pathways. These studies revealed that the anaerobic catabolism of aromatic compounds is more diverse and widespread than previously thought, and the complex metabolic and stress programs associated with the use of aromatic compounds under anaerobic conditions are starting to be unraveled. Anaerobic biotransformation processes based on unprecedented enzymes and pathways with novel metabolic capabilities, as well as the design of novel regulatory circuits and catabolic networks of great biotechnological potential in synthetic biology, are now feasible to approach.

  2. Trehalose metabolism genes render rice white tip nematode Aphelenchoides besseyi (Nematoda: Aphelenchoididae) resistant to an anaerobic environment

    Science.gov (United States)

    Chen, Qiaoli; Zhang, Ruizhi; Ling, Yaming

    2018-01-01

    ABSTRACT After experiencing anaerobic environments, Aphelenchoides besseyi will enter a state of suspended animation known as anoxybiosis, during which it may use trehalose as an energy supply to survive. To explore the function of trehalose metabolism, two trehalose-6-phosphate synthase (TPS) genes (Ab-tps1 and Ab-tps2) encoding enzymes catalysing trehalose synthesis, and three trehalase (TRE) genes (Ab-ntre1, Ab-ntre2 and Ab-atre) encoding enzymes catalysing the hydrolysis of trehalose, were identified and investigated. Ab-tps1 and Ab-tps2 were active during certain periods of anoxybiosis for A. besseyi, and Ab-tps2, Ab-ntre1, Ab-ntre2 and Ab-atre were active during certain periods of recovery. The results of RNA interference experiments suggested that TRE genes regulated each other and both TPS genes, while a single TPS gene only regulated the other TPS gene. However, two TPS genes together could regulate TRE genes, which indicated a feedback mechanism between these genes. All these genes also positively regulated the survival and resumption of active metabolism of the nematode. Genes functioning at re-aeration have a greater impact on nematode survival, suggesting that these genes could play roles in anoxybiosis regulation, but may function within restricted time frames. Changes in trehalose levels matched changes in TRE activity during the anoxybiosis–re-aeration process, suggesting that trehalose may act as an energy supply source. The observation of up-regulation of TPS genes during anoxybiosis suggested a possible signal role of trehalose. Trehalose metabolism genes could also work together to control trehalose levels at a certain level when the nematode is under anaerobic conditions. PMID:29158222

  3. Toxic effect evaluation of the lead acetate and chromium chloride on anaerobic bacterial metabolism

    International Nuclear Information System (INIS)

    Wills, Beatriz; Naranjo, Fernando

    2004-01-01

    The toxicity of trivalent chromium and lead to anaerobic sludge system was studied. Performed assay was tested in 60 mL serum vials, the toxicity test to succeed in two steps, first with formic acid and then whey powder as a substrate. Anaerobic toxicity assays were performed taking into account, methane gas production and oxidation-reduction potential (ORP) rate, these tests were considered a useful indicator for monitoring a anaerobic sludge suffering from toxicants, over 72 hours with metals dosage against the control. First of all, exploratory assays in order to know different chromium and lead concentrations were carried out. The assays degradation activity reduced methane by 50% that came into contact with 3.322 mg Cr 3 +/L and 1.415 mg Pb/L and 2.291 mg Cr 3 +/Land 1.982 mg Pb/L with formic acid and whey powder as a substrate respectively. Heavy metal concentrations that caused 50% inhibition of methanogenesis during whey and formic acid methanation indicated that toxicity decreased in order Pb>>Cr

  4. Metabolic engineering for high glycerol production by the anaerobic cultures of Saccharomyces cerevisiae.

    Science.gov (United States)

    Semkiv, Marta V; Dmytruk, Kostyantyn V; Abbas, Charles A; Sibirny, Andriy A

    2017-06-01

    Glycerol is used by the cosmetic, paint, automotive, food, and pharmaceutical industries and for production of explosives. Currently, glycerol is available in commercial quantities as a by-product from biodiesel production, but the purity and the cost of its purification are prohibitive. The industrial production of glycerol by glucose aerobic fermentation using osmotolerant strains of the yeasts Candida sp. and Saccharomyces cerevisiae has been described. A major drawback of the aerobic process is the high cost of production. For this reason, the development of yeast strains that effectively convert glucose to glycerol anaerobically is of great importance. Due to its ability to grow under anaerobic conditions, the yeast S. cerevisiae is an ideal system for the development of this new biotechnological platform. To increase glycerol production and accumulation from glucose, we lowered the expression of TPI1 gene coding for triose phosphate isomerase; overexpressed the fused gene consisting the GPD1 and GPP2 parts coding for glycerol-3-phosphate dehydrogenase and glycerol-3-phosphate phosphatase, respectively; overexpressed the engineered FPS1 gene that codes for aquaglyceroporin; and overexpressed the truncated gene ILV2 that codes for acetolactate synthase. The best constructed strain produced more than 20 g of glycerol/L from glucose under micro-aerobic conditions and 16 g of glycerol/L under anaerobic conditions. The increase in glycerol production led to a drop in ethanol and biomass accumulation.

  5. Pathways and bioenergetics of anaerobic carbon monoxide fermentation.

    OpenAIRE

    Martijn eDiender; Alfons J.M. Stams; Alfons J.M. Stams; Diana Z. Sousa

    2015-01-01

    Carbon monoxide can act as a substrate for different modes of fermentative anaerobic metabolism. The trait of utilizing CO is spread among a diverse group of microorganisms, including members of bacteria as well as archaea. Over the last decade this metabolism has gained interest due to the potential of converting CO rich gas, such as synthesis gas, into bio-based products. Three main types of fermentative CO metabolism can be distinguished: hydrogenogenesis, methanogenesis and acetogenesis, ...

  6. Characterization of the periplasmic redox network that sustains the versatile anaerobic metabolism of Shewanella oneidensis MR-1

    Directory of Open Access Journals (Sweden)

    Mónica N. Alves

    2015-06-01

    Full Text Available The versatile anaerobic metabolism of the Gram-negative bacterium Shewanella oneidensis MR-1 (SOMR-1 relies on a multitude of redox proteins found in its periplasm. Most are multiheme cytochromes that carry electrons to terminal reductases of insoluble electron acceptors located at the cell surface, or bona fide terminal reductases of soluble electron acceptors. In this study, the interaction network of several multiheme cytochromes was explored by a combination of NMR spectroscopy, activity assays followed by UV-visible spectroscopy and comparison of surface electrostatic potentials. From these data the small tetraheme cytochrome (STC emerges as the main periplasmic redox shuttle in SOMR-1. It accepts electrons from CymA and distributes them to a number of terminal oxidoreductases involved in the respiration of various compounds. STC is also involved in the electron transfer pathway to reduce nitrite by interaction with the octaheme tetrathionate reductase (OTR, but not with cytochrome c nitrite reductase (ccNiR. In the main pathway leading the metal respiration STC pairs with flavocytochrome c (FccA, the other major periplasmic cytochrome, which provides redundancy in this important pathway. The data reveals that the two proteins compete for the binding site at the surface of MtrA, the decaheme cytochrome inserted on the periplasmic side of the MtrCAB-OmcA outer-membrane complex. However, this is not observed for the MtrA homologues. Indeed, neither STC nor FccA interact with MtrD, the best replacement for MtrA, and only STC is able to interact with the decaheme cytochrome DmsE of the outer-membrane complex DmsEFABGH. Overall, these results shown that STC plays a central role in the anaerobic respiratory metabolism of SOMR-1. Nonetheless, the trans-periplasmic electron transfer chain is functionally resilient as a consequence of redundancies that arise from the presence of alternative pathways that bypass/compete with STC.

  7. A Metagenomics-Based Metabolic Model of Nitrate-Dependent Anaerobic Oxidation of Methane by Methanoperedens-Like Archaea

    Science.gov (United States)

    Arshad, Arslan; Speth, Daan R.; de Graaf, Rob M.; Op den Camp, Huub J. M.; Jetten, Mike S. M.; Welte, Cornelia U.

    2015-01-01

    Methane oxidation is an important process to mitigate the emission of the greenhouse gas methane and further exacerbating of climate forcing. Both aerobic and anaerobic microorganisms have been reported to catalyze methane oxidation with only a few possible electron acceptors. Recently, new microorganisms were identified that could couple the oxidation of methane to nitrate or nitrite reduction. Here we investigated such an enrichment culture at the (meta) genomic level to establish a metabolic model of nitrate-driven anaerobic oxidation of methane (nitrate-AOM). Nitrate-AOM is catalyzed by an archaeon closely related to (reverse) methanogens that belongs to the ANME-2d clade, tentatively named Methanoperedens nitroreducens. Methane may be activated by methyl-CoM reductase and subsequently undergo full oxidation to carbon dioxide via reverse methanogenesis. All enzymes of this pathway were present and expressed in the investigated culture. The genome of the archaeal enrichment culture encoded a variety of enzymes involved in an electron transport chain similar to those found in Methanosarcina species with additional features not previously found in methane-converting archaea. Nitrate reduction to nitrite seems to be located in the pseudoperiplasm and may be catalyzed by an unusual Nar-like protein complex. A small part of the resulting nitrite is reduced to ammonium which may be catalyzed by a Nrf-type nitrite reductase. One of the key questions is how electrons from cytoplasmically located reverse methanogenesis reach the nitrate reductase in the pseudoperiplasm. Electron transport in M. nitroreducens probably involves cofactor F420 in the cytoplasm, quinones in the cytoplasmic membrane and cytochrome c in the pseudoperiplasm. The membrane-bound electron transport chain includes F420H2 dehydrogenase and an unusual Rieske/cytochrome b complex. Based on genome and transcriptome studies a tentative model of how central energy metabolism of nitrate-AOM could work is

  8. The metabolic costs of improving ethanol yield by reducing glycerol formation capacity under anaerobic conditions in Saccharomyces cerevisiae.

    Science.gov (United States)

    Pagliardini, Julien; Hubmann, Georg; Alfenore, Sandrine; Nevoigt, Elke; Bideaux, Carine; Guillouet, Stephane E

    2013-03-28

    Finely regulating the carbon flux through the glycerol pathway by regulating the expression of the rate controlling enzyme, glycerol-3-phosphate dehydrogenase (GPDH), has been a promising approach to redirect carbon from glycerol to ethanol and thereby increasing the ethanol yield in ethanol production. Here, strains engineered in the promoter of GPD1 and deleted in GPD2 were used to investigate the possibility of reducing glycerol production of Saccharomyces cerevisiae without jeopardising its ability to cope with process stress during ethanol production. For this purpose, the mutant strains TEFmut7 and TEFmut2 with different GPD1 residual expression were studied in Very High Ethanol Performance (VHEP) fed-batch process under anaerobic conditions. Both strains showed a drastic reduction of the glycerol yield by 44 and 61% while the ethanol yield improved by 2 and 7% respectively. TEFmut2 strain showing the highest ethanol yield was accompanied by a 28% reduction of the biomass yield. The modulation of the glycerol formation led to profound redox and energetic changes resulting in a reduction of the ATP yield (YATP) and a modulation of the production of organic acids (acetate, pyruvate and succinate). Those metabolic rearrangements resulted in a loss of ethanol and stress tolerance of the mutants, contrarily to what was previously observed under aerobiosis. This work demonstrates the potential of fine-tuned pathway engineering, particularly when a compromise has to be found between high product yield on one hand and acceptable growth, productivity and stress resistance on the other hand. Previous study showed that, contrarily to anaerobiosis, the resulting gain in ethanol yield was accompanied with no loss of ethanol tolerance under aerobiosis. Moreover those mutants were still able to produce up to 90 gl-1 ethanol in an anaerobic SSF process. Fine tuning metabolic strategy may then open encouraging possibilities for further developing robust strains with improved

  9. Microbial diversity in a full-scale anaerobic reactor treating high ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-03-22

    Mar 22, 2012 ... nitrogen (TN), total phosphorus (TP) and acetic acid of influent and effluent from the plant ... Mean treatment results for various parameters of water quality by the plant. Parameter .... in the metabolism of proteins, peptides and starch. They might ... methylovorans hollandica strain DMS1T were methanol, ...

  10. Isolation and Cultivation of Anaerobes

    DEFF Research Database (Denmark)

    Aragao Börner, Rosa

    2016-01-01

    Anaerobic microorganisms play important roles in different biotechnological processes. Their complex metabolism and special cultivation requirements have led to less isolated representatives in comparison to their aerobic counterparts.In view of that, the isolation and cultivation of anaerobic...

  11. Co-existence of Anaerobic Ammonium Oxidation Bacteria and Denitrifying Anaerobic Methane Oxidation Bacteria in Sewage Sludge: Community Diversity and Seasonal Dynamics

    DEFF Research Database (Denmark)

    Xu, Sai; Lu, Wenjing; Mustafa, Muhammad Farooq

    2017-01-01

    Anaerobic ammonium oxidation (ANAMMOX) and denitrifying anaerobic methane oxidation (DAMO) have been recently discovered as relevant processes in the carbon and nitrogen cycles of wastewater treatment plants. In this study, the seasonal dynamics of ANAMMOX and DAMO bacterial community structures......, and an unknown cluster was primarily detected in autumn and winter. Similar patterns of seasonal variation in the community structure of DAMO bacteria were also observed. Group B was the dominant in spring and summer, whereas in autumn and winter, group A and group B presented almost the same proportion...

  12. Methane Seep in Shallow-Water Permeable Sediment Harbors High Diversity of Anaerobic Methanotrophic Communities, Elba, Italy.

    Science.gov (United States)

    Ruff, S Emil; Kuhfuss, Hanna; Wegener, Gunter; Lott, Christian; Ramette, Alban; Wiedling, Johanna; Knittel, Katrin; Weber, Miriam

    2016-01-01

    The anaerobic oxidation of methane (AOM) is a key biogeochemical process regulating methane emission from marine sediments into the hydrosphere. AOM is largely mediated by consortia of anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB), and has mainly been investigated in deep-sea sediments. Here we studied methane seepage at four spots located at 12 m water depth in coastal, organic carbon depleted permeable sands off the Island of Elba (Italy). We combined biogeochemical measurements, sequencing-based community analyses and in situ hybridization to investigate the microbial communities of this environment. Increased alkalinity, formation of free sulfide and nearly stoichiometric methane oxidation and sulfate reduction rates up to 200 nmol g(-1) day(-1) indicated the predominance of sulfate-coupled AOM. With up to 40 cm thickness the zones of AOM activity were unusually large and occurred in deeper sediment horizons (20-50 cm below seafloor) as compared to diffusion-dominated deep-sea seeps, which is likely caused by advective flow of pore water due to the shallow water depth and permeability of the sands. Hydrodynamic forces also may be responsible for the substantial phylogenetic and unprecedented morphological diversity of AOM consortia inhabiting these sands, including the clades ANME-1a/b, ANME-2a/b/c, ANME-3, and their partner bacteria SEEP-SRB1a and SEEP-SRB2. High microbial dispersal, the availability of diverse energy sources and high habitat heterogeneity might explain that the emission spots shared few microbial taxa, despite their physical proximity. Although the biogeochemistry of this shallow methane seep was very different to that of deep-sea seeps, their key functional taxa were very closely related, which supports the global dispersal of key taxa and underlines strong selection by methane as the predominant energy source. Mesophilic, methane-fueled ecosystems in shallow-water permeable sediments may comprise distinct

  13. Methane seep in shallow-water permeable sediment harbors high diversity of anaerobic methanotrophic communities, Elba, Italy

    Directory of Open Access Journals (Sweden)

    S Emil Ruff

    2016-03-01

    Full Text Available The anaerobic oxidation of methane (AOM is a key biogeochemical process regulating methane emission from marine sediments into the hydrosphere. AOM is largely mediated by consortia of anaerobic methanotrophic archaea (ANME and sulfate-reducing bacteria (SRB, and has mainly been investigated in deep-sea sediments. Here we studied methane seepage at four spots located at 12 m water depth in coastal, organic-carbon depleted permeable sands off the Island of Elba (Italy. We combined biogeochemical measurements, sequencing-based community analyses and in situ hybridization to investigate the microbial communities of this environment. Increased alkalinity, formation of free sulfide and nearly stoichiometric methane oxidation and sulfate reduction rates up to 200 nmol g-1 day-1 indicated the predominance of sulfate-coupled AOM. With up to 40 cm thickness the zones of AOM activity were unusually large and occurred in deeper sediment horizons (20–50 cm below seafloor as compared to diffusion-dominated deep-sea seeps, which is likely caused by advective flow of pore water due to the shallow water depth and permeability of the sands. Hydrodynamic forces also may be responsible for the substantial phylogenetic and unprecedented morphological diversity of AOM consortia inhabiting these sands, including the clades ANME-1a/b, ANME-2a/b/c, ANME-3 and their partner bacteria SEEP-SRB1a and SEEP-SRB2. High microbial dispersal, the availability of diverse energy sources and high habitat heterogeneity might explain that the emission spots shared few microbial taxa, despite their physical proximity. Although the biogeochemistry of this shallow methane seep was very different to that of deep-sea seeps, their key functional taxa were very closely related, which supports the global dispersal of key taxa and underlines strong selection by methane as the predominant energy source. Mesophilic, methane-fueled ecosystems in shallow-water permeable sediments may comprise

  14. Methane Seep in Shallow-Water Permeable Sediment Harbors High Diversity of Anaerobic Methanotrophic Communities, Elba, Italy

    Science.gov (United States)

    Ruff, S. Emil; Kuhfuss, Hanna; Wegener, Gunter; Lott, Christian; Ramette, Alban; Wiedling, Johanna; Knittel, Katrin; Weber, Miriam

    2016-01-01

    The anaerobic oxidation of methane (AOM) is a key biogeochemical process regulating methane emission from marine sediments into the hydrosphere. AOM is largely mediated by consortia of anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB), and has mainly been investigated in deep-sea sediments. Here we studied methane seepage at four spots located at 12 m water depth in coastal, organic carbon depleted permeable sands off the Island of Elba (Italy). We combined biogeochemical measurements, sequencing-based community analyses and in situ hybridization to investigate the microbial communities of this environment. Increased alkalinity, formation of free sulfide and nearly stoichiometric methane oxidation and sulfate reduction rates up to 200 nmol g-1 day-1 indicated the predominance of sulfate-coupled AOM. With up to 40 cm thickness the zones of AOM activity were unusually large and occurred in deeper sediment horizons (20–50 cm below seafloor) as compared to diffusion-dominated deep-sea seeps, which is likely caused by advective flow of pore water due to the shallow water depth and permeability of the sands. Hydrodynamic forces also may be responsible for the substantial phylogenetic and unprecedented morphological diversity of AOM consortia inhabiting these sands, including the clades ANME-1a/b, ANME-2a/b/c, ANME-3, and their partner bacteria SEEP-SRB1a and SEEP-SRB2. High microbial dispersal, the availability of diverse energy sources and high habitat heterogeneity might explain that the emission spots shared few microbial taxa, despite their physical proximity. Although the biogeochemistry of this shallow methane seep was very different to that of deep-sea seeps, their key functional taxa were very closely related, which supports the global dispersal of key taxa and underlines strong selection by methane as the predominant energy source. Mesophilic, methane-fueled ecosystems in shallow-water permeable sediments may comprise distinct

  15. Effect of creatine on aerobic and anaerobic metabolism in skeletal muscle in swimmers.

    OpenAIRE

    Thompson, C H; Kemp, G J; Sanderson, A L; Dixon, R M; Styles, P; Taylor, D J; Radda, G K

    1996-01-01

    OBJECTIVE: To examine the effect of a relatively low dose of creatine on skeletal muscle metabolism and oxygen supply in a group of training athletes. METHODS: 31P magnetic resonance and near-infrared spectroscopy were used to study calf muscle metabolism in a group of 10 female members of a university swimming team. Studies were performed before and after a six week period of training during which they took either 2 g creatine daily or placebo. Calf muscle metabolism and creatine/choline rat...

  16. LakeMetabolizer: An R package for estimating lake metabolism from free-water oxygen using diverse statistical models

    Science.gov (United States)

    Winslow, Luke; Zwart, Jacob A.; Batt, Ryan D.; Dugan, Hilary; Woolway, R. Iestyn; Corman, Jessica; Hanson, Paul C.; Read, Jordan S.

    2016-01-01

    Metabolism is a fundamental process in ecosystems that crosses multiple scales of organization from individual organisms to whole ecosystems. To improve sharing and reuse of published metabolism models, we developed LakeMetabolizer, an R package for estimating lake metabolism from in situ time series of dissolved oxygen, water temperature, and, optionally, additional environmental variables. LakeMetabolizer implements 5 different metabolism models with diverse statistical underpinnings: bookkeeping, ordinary least squares, maximum likelihood, Kalman filter, and Bayesian. Each of these 5 metabolism models can be combined with 1 of 7 models for computing the coefficient of gas exchange across the air–water interface (k). LakeMetabolizer also features a variety of supporting functions that compute conversions and implement calculations commonly applied to raw data prior to estimating metabolism (e.g., oxygen saturation and optical conversion models). These tools have been organized into an R package that contains example data, example use-cases, and function documentation. The release package version is available on the Comprehensive R Archive Network (CRAN), and the full open-source GPL-licensed code is freely available for examination and extension online. With this unified, open-source, and freely available package, we hope to improve access and facilitate the application of metabolism in studies and management of lentic ecosystems.

  17. [Phylogenetic diversity and activity of anaerobic microorganisms of high-temperature horizons of the Dagang Oilfield (China)].

    Science.gov (United States)

    Nazina, T N; Shestakova, N M; Grigor'ian, A A; Mikhaĭlova, E M; Turova, T P; Poltaraus, A B; Feng, C; Ni, F; Beliaev, S S

    2006-01-01

    The number of microorganisms of major metabolic groups and the rates of sulfate-reducing and methanogenic processes in the formation waters of the high-temperature horizons of Dagang oilfield have been determined. Using cultural methods, it was shown that the microbial community contained aerobic bacteria oxidizing crude oil, anaerobic fermentative bacteria, sulfate-reducing bacteria, and methanogenic bacteria. Using cultural methods, the possibility of methane production from a mixture of hydrogen and carbon dioxide (H2 + CO2) and from acetate was established, and this result was confirmed by radioassays involving NaH14CO3 and 14CH3COONa. Analysis of 16S rDNA of enrichment cultures of methanogens demonstrated that these microorganisms belong to Methanothermobacter sp. (M. thermoautotrophicus), which consumes hydrogen and carbon dioxide as basic substrates. The genes of acetate-utilizing bacteria were not identified. Phylotypes of the representatives of Thermococcus spp. were found among 16S rDNAs of archaea. 16S rRNA genes of bacterial clones belong to the orders Thermoanaerobacteriales (Thermoanaerobacter, Thermovenabulum, Thermacetogenium, and Coprothermobacter spp.), Thermotogales, Nitrospirales (Thermodesulfovibrio sp.) and Planctomycetales. 16S rDNA of a bacterium capable of oxidizing acetate in the course of syntrophic growth with H2-utilizing methanogens was found at high-temperature petroleum reservoirs for the first time. These results provide further insight into the composition of microbial communities of high-temperature petroleum reservoirs, indicating that syntrophic processes play an important part in acetate degradation accompanied by methane production.

  18. Relationship between metabolic and genomic diversity in sesame (Sesamum indicum L.

    Directory of Open Access Journals (Sweden)

    Karlovsky Petr

    2008-05-01

    Full Text Available Abstract Background Diversity estimates in cultivated plants provide a rationale for conservation strategies and support the selection of starting material for breeding programs. Diversity measures applied to crops usually have been limited to the assessment of genome polymorphism at the DNA level. Occasionally, selected morphological features are recorded and the content of key chemical constituents determined, but unbiased and comprehensive chemical phenotypes have not been included systematically in diversity surveys. Our objective in this study was to assess metabolic diversity in sesame by nontargeted metabolic profiling and elucidate the relationship between metabolic and genome diversity in this crop. Results Ten sesame accessions were selected that represent most of the genome diversity of sesame grown in India, Western Asia, Sudan and Venezuela based on previous AFLP studies. Ethanolic seed extracts were separated by HPLC, metabolites were ionized by positive and negative electrospray and ions were detected with an ion trap mass spectrometer in full-scan mode for m/z from 50 to 1000. Genome diversity was determined by Amplified Fragment Length Polymorphism (AFLP using eight primer pair combinations. The relationship between biodiversity at the genome and at the metabolome levels was assessed by correlation analysis and multivariate statistics. Conclusion Patterns of diversity at the genomic and metabolic levels differed, indicating that selection played a significant role in the evolution of metabolic diversity in sesame. This result implies that when used for the selection of genotypes in breeding and conservation, diversity assessment based on neutral DNA markers should be complemented with metabolic profiles. We hypothesize that this applies to all crops with a long history of domestication that possess commercially relevant traits affected by chemical phenotypes.

  19. Shape shifting predicts ontogenetic changes in metabolic scaling in diverse aquatic invertebrates

    DEFF Research Database (Denmark)

    Glazier, Douglas S.; Hirst, Andrew G.; Atkinson, D.

    2016-01-01

    in metabolic scaling that deviate from 3/4-power scaling predicted by general models. Here, we show that in diverse aquatic invertebrates, ontogenetic shifts in the scaling of routine metabolic rate from near isometry (bR = scaling exponent approx. 1) to negative allometry (bR

  20. Effects of inorganic carbon on the nitrous oxide emissions and microbial diversity of an anaerobic ammonia oxidation reactor.

    Science.gov (United States)

    Zhang, Wenjie; Wang, Dunqiu; Jin, Yue

    2018-02-01

    Inorganic carbon (IC) is important for anaerobic ammonium oxidation (anammox). In this study, the effects of the IC concentration on N 2 O emissions and microbial diversity in an anammox reactor were investigated. N 2 O emissions were positively correlated with IC concentrations, and IC concentrations in the range of 55-130 mg/L were optimal, considering the nitrogen removal rate and N 2 O emissions. High IC concentrations resulted in the formation of CaCO 3 on the surface of anammox granules, which impacted the diffusion conditions of the substrate. Microbial community analysis indicated that high IC concentrations decreased the populations of specific bacteria, such as Achromobacter spanius strain YJART-7, Achromobacter xylosoxidans strain IHB B 6801, and Denitratisoma oestradiolicum clone 20b_15. D. oestradiolicum clone 20b_15 appeared to be the key contributor to N 2 O emissions. High N 2 O emissions may result from changes in organic carbon sources, which lead to denitrification by D. oestradiolicum clone 20b_15. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Pyruvate dehydrogenase complexes from the equine nematode, Parascaris equorum, and the canine cestode, Dipylidium caninum, helminths exhibiting anaerobic mitochondrial metabolism.

    Science.gov (United States)

    Diaz, F; Komuniecki, R W

    1994-10-01

    The pyruvate dehydrogenase complex (PDC) has been purified to apparent homogeneity from 2 parasitic helminths exhibiting anaerobic mitochondrial metabolism, the equine nematode, Parascaris equorum, and the canine cestode, Dipylidium caninum. The P. equorum PDC yielded 7 major bands when separated by SDS-PAGE. The bands of 72, 55-53.5, 41 and 36 kDa corresponded to E2, E3, E1 alpha and E1 beta, respectively. The complex also contained additional unidentified proteins of 43 and 45 kDa. Incubation of the complex with [2-14C]pyruvate resulted in the acetylation of only E2. These results suggest that the P. equorum PDC lacks protein X and exhibits an altered subunit composition, as has been described previously for the PDC of the related nematode, Ascaris suum. In contrast, the D. caninum PDC yielded only four major bands after SDS-PAGE of 59, 58, 39 and 34 kDa, which corresponded to E3, E2, E1 alpha and E1 beta, respectively. Incubation of the D. caninum complex with [2-14C]pyruvate resulted in the acetylation of E2 and a second protein which comigrated with E3, suggesting that the D. caninum complex contained protein X and had a subunit composition similar to PDCs from other eukaryotic organisms. Both helminth complexes appeared less sensitive to inhibition by elevated NADH/NAD+ ratios than complexes isolated from aerobic organisms, as would be predicted for PDCs from organisms exploiting microaerobic habitats. These results suggest that although these helminths have similar anaerobic mitochondrial pathways, they contain significantly different PDCs.

  2. Genes associated to lactose metabolism illustrate the high diversity of Carnobacterium maltaromaticum

    DEFF Research Database (Denmark)

    Iskandar, Christelle F.; Cailliez-Grimal, Catherine; Rahman, Abdur

    2016-01-01

    The dairy population of Carnobacterium maltaromaticum is characterized by a high diversity suggesting a high diversity of the genetic traits linked to the dairy process. As lactose is the main carbon source in milk, the genetics of lactose metabolism was investigated in this LAB. Comparative...

  3. Metabolic diversity of the heterotrophic microorganisms and potential link to pollution of the Rouge River

    Energy Technology Data Exchange (ETDEWEB)

    Tiquia, S.M., E-mail: smtiquia@umd.umich.ed [Department of Natural Sciences, University of Michigan, 115F Science Building, Dearborn, MI 48128 (United States)

    2010-05-15

    The heterotrophic microbial communities of the Rouge River were tracked using Biolog Ecoplates to understand the metabolic diversity at different temporal and spatial scales, and potential link to river pollution. Site less impacted by anthrophogenic sources (site 1), showed markedly lower metabolic diversity. The only substrates that were utilized in the water samples were carbohydrates. Sites more impacted by anthrophogenic sources (sites 8 and 9) showed higher metabolic diversity. Higher functional diversity was linked to the physico-chemical and biological properties of the water samples (i.e. higher concentrations of DO, DOC, chlorophyll, and bacterial density). Biolog analysis was found to be useful in differentiating metabolic diversity between microbial communities; in determining factors that most influence the separation of communities; and in identifying which substrates were most utilized by the communities. It can also be used as an effective ecological indicator of changes in river function attributable to urbanization and pollution. - BIOLOG differentiated metabolic diversity between microbial communities and can be used as ecological indicator of river function attributable to urbanization and pollution.

  4. Metabolic diversity of the heterotrophic microorganisms and potential link to pollution of the Rouge River

    International Nuclear Information System (INIS)

    Tiquia, S.M.

    2010-01-01

    The heterotrophic microbial communities of the Rouge River were tracked using Biolog Ecoplates to understand the metabolic diversity at different temporal and spatial scales, and potential link to river pollution. Site less impacted by anthrophogenic sources (site 1), showed markedly lower metabolic diversity. The only substrates that were utilized in the water samples were carbohydrates. Sites more impacted by anthrophogenic sources (sites 8 and 9) showed higher metabolic diversity. Higher functional diversity was linked to the physico-chemical and biological properties of the water samples (i.e. higher concentrations of DO, DOC, chlorophyll, and bacterial density). Biolog analysis was found to be useful in differentiating metabolic diversity between microbial communities; in determining factors that most influence the separation of communities; and in identifying which substrates were most utilized by the communities. It can also be used as an effective ecological indicator of changes in river function attributable to urbanization and pollution. - BIOLOG differentiated metabolic diversity between microbial communities and can be used as ecological indicator of river function attributable to urbanization and pollution.

  5. Kinetics of Butyrate, Acetate, and Hydrogen Metabolism in a Thermophilic, Anaerobic, Butyrate-Degrading Triculture

    OpenAIRE

    Ahring, Birgitte K.; Westermann, Peter

    1987-01-01

    Kinetics of butyrate, acetate, and hydrogen metabolism were determined with butyrate-limited, chemostat-grown tricultures of a thermophilic butyrate-utilizing bacterium together with Methanobacterium thermoautotrophicum and the TAM organism, a thermophilic acetate-utilizing methanogenic rod. Kinetic parameters were determined from progress curves fitted to the integrated form of the Michaelis-Menten equation. The apparent half-saturation constants, Km, for butyrate, acetate, and dissolved hyd...

  6. High abundance and diversity of nitrite-dependent anaerobic methane-oxidizing bacteria in a paddy field profile.

    Science.gov (United States)

    Zhou, Leiliu; Wang, Yu; Long, Xi-En; Guo, Jianhua; Zhu, Guibing

    2014-11-01

    The discovery of nitrite-dependent anaerobic methane oxidation (n-damo) mediated by 'Candidatus Methylomirabilis oxyfera' with nitrite and methane as substrates has connected biogeochemical carbon and nitrogen cycles in a new way. The paddy fields often carry substantial methane and nitrate, thus may be a favorable habitat for n-damo bacteria. In this paper, the vertical-temporal molecular fingerprints of M. oxyfera-like bacteria, including abundance and community composition, were investigated in a paddy soil core in Jiangyin, near the Yangtze River. Through qPCR investigation, high abundance of M. oxyfera-like bacteria up to 1.0 × 10(8) copies (g d.w.s.)(-1) in summer and 8.5 × 10(7) copies (g d.w.s.)(-1) in winter was observed in the ecotone of soil and groundwater in the paddy soil core, which was the highest in natural environments to our knowledge. In the ecotone, the ratio of M. oxyfera-like bacteria to total bacteria reached peak values of 2.80% in summer and 4.41% in winter. Phylogenetic analysis showed n-damo bacteria in the paddy soil were closely related to M. oxyfera and had high diversity in the soil/groundwater ecotone. All of the results indicated the soil/groundwater ecotone of the Jiangyin paddy field was a favorable environment for the growth of n-damo bacteria. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2016-05-01

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

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

    International Nuclear Information System (INIS)

    Kiene, R.P.; Oremland, R.S.; Catena, A.; Miller, L.G.; Capone, A.G.

    1986-01-01

    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 [ 14 C]DMS, metabolism by sediments resulted in a 14 CH 4 / 14 CO 2 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 14 CO 2 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 [ 14 C]-DMS to yield a 14 CH 4 / 14 CO 2 ratio of ∼ 2.8

  9. Anoxia tolerance and anaerobic metabolism in two tropical weevil species (Coleoptera, Curculionidae).

    Science.gov (United States)

    Kölsch, G

    2001-10-01

    Although the two curculionid beetle species Cosmopolites sordidus and Temnoschoita nigroplagiata are found in the same habitat (banana plantation), they differ with respect to their microhabitat preference and thereby in their risk of being submerged after rain. The physiological characteristics of the two species that might be important in this context were investigated. As expected, C. sordidus is more resistant to submergence (faster recovery, lower mortality: 30% after 9 days submergence at 20 degrees C); this can be attributed to a generally lower metabolic rate, higher glycogen reserves (135 micromol glycosyl units x g FW(-1)) and a moderate lactate production under anoxia. In T. nigroplagiata, the glycogen reserves are almost completely depleted after 1 day submergence at 20 degrees C and a higher proportion of this glycogen can recovered as lactate (16%). During submergence, the adenylate energy charge falls in both species to 0.2 or below, whereas the total adenine nucleotide content decreases only slowly, especially in C. sordidus.

  10. Drug metabolism and pharmacokinetic diversity of ranunculaceae medicinal compounds.

    Science.gov (United States)

    Hao, Da-Cheng; Ge, Guang-Bo; Xiao, Pei-Gen; Wang, Ping; Yang, Ling

    2015-01-01

    The wide-reaching distributed angiosperm family Ranunculaceae has approximately 2200 species in around 60 genera. Chemical components of this family include several representative groups: benzylisoquinoline alkaloid (BIA), ranunculin, triterpenoid saponin and diterpene alkaloid, etc. Their extensive clinical utility has been validated by traditional uses of thousands of years and current evidence-based medicine studies. Drug metabolism and pharmacokinetic (DMPK) studies of plant-based natural products are an indispensable part of comprehensive medicinal plant exploration, which could facilitate conservation and sustainable utilization of Ranunculaceae pharmaceutical resources, as well as new chemical entity development with improved DMPK parameters. However, DMPK characteristics of Ranunculaceaederived medicinal compounds have not been summarized. Black cohosh (Cimicifuga) and goldenseal (Hydrastis) raise concerns of herbdrug interaction. DMPK studies of other Ranunculaceae genera, e.g., Nigella, Delphinium, Aconitum, Trollius, and Coptis, are also rapidly increasing and becoming more and more clinically relevant. In this contribution, we highlight the up-to-date awareness, as well as the challenges around the DMPK-related issues in optimization of drug development and clinical practice of Ranunculaceae compounds. Herb-herb interaction of Ranunculaceae herb-containing traditional Chinese medicine (TCM) formula could significantly influence the in vivo pharmacokinetic behavior of compounds thereof, which may partially explain the complicated therapeutic mechanism of TCM formula. Although progress has been made on revealing the absorption, distribution, metabolism, excretion and toxicity (ADME/T) of Ranunculaceae compounds, there is a lack of DMPK studies of traditional medicinal genera Aquilegia, Thalictrum and Clematis. Fluorescent probe compounds could be promising substrate, inhibitor and/or inducer in future DMPK studies of Ranunculaceae compounds. A better

  11. Synergetic effect of pH and biochemical components on bacterial diversity during mesophilic anaerobic fermentation of biomass-origin waste.

    Science.gov (United States)

    Lü, F; Shao, L M; Bru, V; Godon, J J; He, P J

    2009-02-01

    To investigate the synergetic effect of pH and biochemical components on bacterial community structure during mesophilic anaerobic degradation of solid wastes with different origins, and under acidic or neutral conditions. The bacterial community in 16 samples of solid wastes with different biochemical compositions and origins was evaluated during mesophilic anaerobic degradation at acidic and neutral pH. Denaturing gradient gel electrophoresis (DGGE) and single-strand conformation polymorphism (SSCP) were used to compare the communities. Multivariate analysis of the DGGE and SSCP results revealed that most of the dominant microbes were dependent on the content of easily degradable carbohydrates in the samples. Furthermore, the dominant microbes were divided into two types, those that preferred an acid environment and those that preferred a neutral environment. A shift in pH was found to change their preference for medium substrates. Although most of the substrates with similar origin and biochemical composition had similar microbial diversity during fermentation, some microbes were found only in substrates with specific origins. For example, two microbes were only found in substrate that contained lignocellulose and animal protein without starch. These microbes were related to micro-organisms that are found in swine manure, as well as in other intestinal or oral niches. In addition, the distribution of fermentation products was less sensitive to the changes in pH and biochemical components than the microbial community. Bacterial diversity during anaerobic degradation of organic wastes was affected by both pH and biochemical components; however, pH exerted a greater effect. The results of this study reveal that control of pH may be an effective method to produce a stable bacterial community and relatively similar product distribution during anaerobic digestion of waste, regardless of variation in the waste feedstocks.

  12. Metabolic Energy Generation In Hydrogenosomes Of The Anaerobic Fungus Neocallimastix - Evidence For A Functional-relationship With Mitochondria

    NARCIS (Netherlands)

    Marvin-Sikkema, F. D.; Driessen, A. J. M.; Gottschal, J. C.; Prins, R. A.

    Anaerobic eukaryotes are often devoid of mitochondria but contain special organelles separated from the cytosol by a single (in fungi) or a double (in protozoa) membrane. Hydrogenosomes from the anaerobic fungus Neocallimastix sp. L2 are thought to catalyse the enzymic steps in the ATP-yielding

  13. Pathways and bioenergetics of anaerobic carbon monoxide fermentation.

    Directory of Open Access Journals (Sweden)

    Martijn eDiender

    2015-11-01

    Full Text Available Carbon monoxide can act as a substrate for different modes of fermentative anaerobic metabolism. The trait of utilizing CO is spread among a diverse group of microorganisms, including members of bacteria as well as archaea. Over the last decade this metabolism has gained interest due to the potential of converting CO rich gas, such as synthesis gas, into bio-based products. Three main types of fermentative CO metabolism can be distinguished: hydrogenogenesis, methanogenesis and acetogenesis, generating hydrogen, methane and acetate, respectively. Here, we review the current knowledge on these three variants of microbial CO metabolism with an emphasis on the potential enzymatic routes and bio-energetics involved.

  14. Pathways and Bioenergetics of Anaerobic Carbon Monoxide Fermentation.

    Science.gov (United States)

    Diender, Martijn; Stams, Alfons J M; Sousa, Diana Z

    2015-01-01

    Carbon monoxide can act as a substrate for different modes of fermentative anaerobic metabolism. The trait of utilizing CO is spread among a diverse group of microorganisms, including members of bacteria as well as archaea. Over the last decade this metabolism has gained interest due to the potential of converting CO-rich gas, such as synthesis gas, into bio-based products. Three main types of fermentative CO metabolism can be distinguished: hydrogenogenesis, methanogenesis, and acetogenesis, generating hydrogen, methane and acetate, respectively. Here, we review the current knowledge on these three variants of microbial CO metabolism with an emphasis on the potential enzymatic routes and bio-energetics involved.

  15. Identity and diversity of archaeal communities during anaerobic co-digestion of chicken feathers and other animal wastes.

    Science.gov (United States)

    Xia, Yun; Massé, Daniel I; McAllister, Tim A; Kong, Yunhong; Seviour, Robert; Beaulieu, Carole

    2012-04-01

    Digestion of raw feathers in anaerobic digesters inoculated with adapted swine manure, slaughterhouse sludge or dairy manure was investigated using twelve 42-L anaerobic digesters at 25°C. After 120days 74%, 49% and 40% added feathers were converted to methane in swine manure, dairy manure and slaughterhouse sludge anaerobic digesters respectively. 16S rRNA gene clone library analyses identified twenty-one operational taxonomic units containing clone sequences from 5 genera, 5 families and 2 phyla of members of the Archaea from 158 sequenced clones. Fluorescence insitu hybridization revealed that methanogens from the Methanomicrobiales, Methanosarcinales and Methanobacteriales constituted a major fraction (>78%) of these Archaea. A high correlation was seen between the distribution of functional archaeal groups and the NH(3)-N levels of digester mixed liquors. The compositions of archaeal communities fed different substrates were statistically significantly different (P<0.05). Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  16. Neighborhood Racial Diversity and Metabolic Syndrome: 2003-2008 National Health and Nutrition Examination Survey.

    Science.gov (United States)

    Li, Kelin; Wen, Ming; Fan, Jessie X

    2018-03-30

    This study investigated the independent association between neighborhood racial/ethnic diversity and metabolic syndrome among US adults, and focused on how this association differed across individual and neighborhood characteristics (i.e., race/ethnicity, sex, age, urbanity, neighborhood poverty). Objectively-measured biomarker data from 2003 to 2008 National Health and Nutrition Examination Survey were linked to census-tract profiles from 2000 decennial census (N = 10,122). Multilevel random intercept logistic regression models were estimated to examine the contextual effects of tract-level racial/ethnic diversity on individual risks of metabolic syndrome. Overall, more than 20% of the study population were identified as having metabolic syndrome, although the prevalence also varied across demographic subgroups and specific biomarkers. Multilevel analyses showed that increased racial/ethnic diversity within a census tract was associated with decreased likelihood of having metabolic syndrome (OR 0.71, 95% CI 0.52-0.96), particularly among female (OR 0.64; 95% CI 0.43-0.96), young adults (OR 0.60; 95% CI 0.39-0.93), and residents living in urban (OR 0.67; 95% CI 0.48-0.93) or poverty neighborhoods (OR 0.54; 95% CI 0.31-0.95). The findings point to the potential benefits of neighborhood racial/ethnic diversity on individual health risks.

  17. Methane-Fueled Syntrophy through Extracellular Electron Transfer: Uncovering the Genomic Traits Conserved within Diverse Bacterial Partners of Anaerobic Methanotrophic Archaea.

    Science.gov (United States)

    Skennerton, Connor T; Chourey, Karuna; Iyer, Ramsunder; Hettich, Robert L; Tyson, Gene W; Orphan, Victoria J

    2017-08-01

    The anaerobic oxidation of methane by anaerobic methanotrophic (ANME) archaea in syntrophic partnership with deltaproteobacterial sulfate-reducing bacteria (SRB) is the primary mechanism for methane removal in ocean sediments. The mechanism of their syntrophy has been the subject of much research as traditional intermediate compounds, such as hydrogen and formate, failed to decouple the partners. Recent findings have indicated the potential for extracellular electron transfer from ANME archaea to SRB, though it is unclear how extracellular electrons are integrated into the metabolism of the SRB partner. We used metagenomics to reconstruct eight genomes from the globally distributed SEEP-SRB1 clade of ANME partner bacteria to determine what genomic features are required for syntrophy. The SEEP-SRB1 genomes contain large multiheme cytochromes that were not found in previously described free-living SRB and also lack periplasmic hydrogenases that may prevent an independent lifestyle without an extracellular source of electrons from ANME archaea. Metaproteomics revealed the expression of these cytochromes at in situ methane seep sediments from three sites along the Pacific coast of the United States. Phylogenetic analysis showed that these cytochromes appear to have been horizontally transferred from metal-respiring members of the Deltaproteobacteria such as Geobacter and may allow these syntrophic SRB to accept extracellular electrons in place of other chemical/organic electron donors. IMPORTANCE Some archaea, known as anaerobic methanotrophs, are capable of converting methane into carbon dioxide when they are growing syntopically with sulfate-reducing bacteria. This partnership is the primary mechanism for methane removal in ocean sediments; however, there is still much to learn about how this syntrophy works. Previous studies have failed to identify the metabolic intermediate, such as hydrogen or formate, that is passed between partners. However, recent analysis of

  18. Effects of cadmium on anaerobic energy metabolism and mRNA expression during air exposure and recovery of an intertidal mollusk Crassostrea virginica

    International Nuclear Information System (INIS)

    Ivanina, Anna V.; Sokolov, Eugene P.; Sokolova, Inna M.

    2010-01-01

    Marine organisms are exposed to periodical oxygen deficiency and pollution stress in estuarine and coastal zones which may strongly affect their performance and survival. We studied the combined effects of exposure to a common pollutant, cadmium (Cd), and intermittent anoxia on anaerobic metabolism, energy status and mRNA expression of 13 genes involved in and/or controlled by the hypoxia inducible factor-1 (HIF-1) pathway in hepatopancreas of an intertidal bivalve, the eastern oyster Crassostrea virginica. In control oysters, prolonged anoxia resulted in a selective suppression of nitric oxide synthase (NOS) and upregulation of cytochrome c oxidase subunit IV (COX4) while the levels of other transcripts remained unchanged. During post-anoxic recovery, mRNA expression of hypoxia inducible factor-1α (HIF-1α) was elevated, phosphoenolpyruvate carboxykinase (PEPCK), NOS and LON protease suppressed, and mRNA expression of other studied genes not changed. Notably, most of the key glycolytic genes that are stimulated by HIF-1 in mammals, either remained unchanged or were downregulated in anoxic oysters suggesting a different mechanism of molecular response to oxygen deficiency. Patterns of transcriptional response during anoxia and reoxygenation were significantly altered by Cd exposure in a gene-specific manner. Anaerobic metabolism (indicated by accumulation of L-alanine, succinate and acetate during anoxia) was also suppressed in Cd-exposed oysters. In control oysters, ATP turnover rate (M ATP ) during anoxia was mostly sustained by anaerobic glycolysis with negligible contributions from ATP and PLA breakdown. In contrast, in Cd-exposed oysters ATP breakdown contributed significantly to anaerobic M ATP . Thus, while control oysters could efficiently defend the ATP levels and tissue energy status during prolonged anoxia, Cd-exposed oysters experienced a disturbance in tissue energy balance indicated by the depletion of ATP, a rapid decline in adenylate energy charge

  19. Effects of cadmium on anaerobic energy metabolism and mRNA expression during air exposure and recovery of an intertidal mollusk Crassostrea virginica

    Energy Technology Data Exchange (ETDEWEB)

    Ivanina, Anna V. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States); Sokolov, Eugene P. [Department of General Surgery, Carolina' s Medical Center, 1000 Blythe Blvd., Charlotte, NC 28203-5871 (United States); Sokolova, Inna M., E-mail: isokolov@uncc.edu [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States)

    2010-09-01

    Marine organisms are exposed to periodical oxygen deficiency and pollution stress in estuarine and coastal zones which may strongly affect their performance and survival. We studied the combined effects of exposure to a common pollutant, cadmium (Cd), and intermittent anoxia on anaerobic metabolism, energy status and mRNA expression of 13 genes involved in and/or controlled by the hypoxia inducible factor-1 (HIF-1) pathway in hepatopancreas of an intertidal bivalve, the eastern oyster Crassostrea virginica. In control oysters, prolonged anoxia resulted in a selective suppression of nitric oxide synthase (NOS) and upregulation of cytochrome c oxidase subunit IV (COX4) while the levels of other transcripts remained unchanged. During post-anoxic recovery, mRNA expression of hypoxia inducible factor-1{alpha} (HIF-1{alpha}) was elevated, phosphoenolpyruvate carboxykinase (PEPCK), NOS and LON protease suppressed, and mRNA expression of other studied genes not changed. Notably, most of the key glycolytic genes that are stimulated by HIF-1 in mammals, either remained unchanged or were downregulated in anoxic oysters suggesting a different mechanism of molecular response to oxygen deficiency. Patterns of transcriptional response during anoxia and reoxygenation were significantly altered by Cd exposure in a gene-specific manner. Anaerobic metabolism (indicated by accumulation of L-alanine, succinate and acetate during anoxia) was also suppressed in Cd-exposed oysters. In control oysters, ATP turnover rate (M{sub ATP}) during anoxia was mostly sustained by anaerobic glycolysis with negligible contributions from ATP and PLA breakdown. In contrast, in Cd-exposed oysters ATP breakdown contributed significantly to anaerobic M{sub ATP}. Thus, while control oysters could efficiently defend the ATP levels and tissue energy status during prolonged anoxia, Cd-exposed oysters experienced a disturbance in tissue energy balance indicated by the depletion of ATP, a rapid decline in

  20. Genomic diversity and versatility of Lactobacillus plantarum, a natural metabolic engineer

    Science.gov (United States)

    2011-01-01

    In the past decade it has become clear that the lactic acid bacterium Lactobacillus plantarum occupies a diverse range of environmental niches and has an enormous diversity in phenotypic properties, metabolic capacity and industrial applications. In this review, we describe how genome sequencing, comparative genome hybridization and comparative genomics has provided insight into the underlying genomic diversity and versatility of L. plantarum. One of the main features appears to be genomic life-style islands consisting of numerous functional gene cassettes, in particular for carbohydrates utilization, which can be acquired, shuffled, substituted or deleted in response to niche requirements. In this sense, L. plantarum can be considered a “natural metabolic engineer”. PMID:21995294

  1. PCR and Omics Based Techniques to Study the Diversity, Ecology and Biology of Anaerobic Fungi: Insights, Challenges and Opportunities

    Czech Academy of Sciences Publication Activity Database

    Edwards, J.E.; Forster, R.; Callaghan, T. M.; Dollhofer, V.; Dagar, S. S.; Cheng, Y.; Chang, J.; Kittelmann, S.; Fliegerová, Kateřina; Puniya, A. K.; Henske, J. K.; Gilmore, S.; O´Malley, M. A.; Griffith, G. W.; Smidt, H.

    2017-01-01

    Roč. 8, č. 8 (2017), č. článku 1657. ISSN 1664-302X R&D Projects: GA MŠk EF15_003/0000460 Institutional support: RVO:67985904 Keywords : anaerobic fungi * Neocallimastigomycota * rumen Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.076, year: 2016

  2. Microbiological Diversity Demonstrates the Potential which Collaboratively Metabolize Nitrogen Oxides ( NOx) under Smog Environmental Stress

    Science.gov (United States)

    Chen, X. Z.; Zhao, X. H.; Chen, X. P.

    2018-03-01

    Recently, smoggy weather has become a daily in large part of China because of rapidly economic growth and accelerative urbanization. Stressed on the smoggy situation and economic growth, the green and environment-friendly technology is necessary to reduce or eliminate the smog and promote the sustainable development of economy. Previous studies had confirmed that nitrogen oxides ( NOx ) is one of crucial factors which forms smog. Microorganisms have the advantages of quickly growth and reproduction and metabolic diversity which can collaboratively Metabolize various NOx. This study will design a kind of bacteria & algae cultivation system which can metabolize collaboratively nitrogen oxides in air and intervene in the local nitrogen cycle. Furthermore, the nitrogen oxides can be transformed into nitrogen gas or assembled in protein in microorganism cell by regulating the microorganism types and quantities and metabolic pathways in the system. Finally, the smog will be alleviated or eliminated because of reduction of nitrogen oxides emission. This study will produce the green developmental methodology.

  3. Investigations into the metabolic diversity of microorganisms as part of microbial diversity

    Energy Technology Data Exchange (ETDEWEB)

    Leadbetter, Jared [California Inst. of Technology (CalTech), Pasadena, CA (United States)

    2016-07-25

    DOE funds supported a key portion of the MBL Microbial Diversity (Woods Hole) program across 6 complete summers. The initial 4 years of the funded period were overseen by two co-Directors, Daniel Buckley (Cornell) and Steve Zinder (Cornell), who then completed their term. The final 2 summers were overseen by 2 new co-Directors, Jared R. Leadbetter (Caltech) and Dianne Newman (Caltech). The 6 funded summer iterations of the course included the incorporation of new themes such as single cell approaches applied to natural microbial communities (cell separation and sorting, genome amplification from single cells, and the use of Nano-SIMS to examine assimilation of carbon and nitrogen from isotopically labeled substrates into single cells), genetics and genomics on bacteria freshly isolated during the course of the programs, quantitative systems biology, and modern quantitative light microscopy.

  4. Anaerobic digestion of swine manure under natural zeolite addition: VFA evolution, cation variation, and related microbial diversity.

    Science.gov (United States)

    Lin, Lin; Wan, Chunli; Liu, Xiang; Lei, Zhongfang; Lee, Duu-Jong; Zhang, Yi; Tay, Joo Hwa; Zhang, Zhenya

    2013-12-01

    Batch experiments were carried out on anaerobic digestion of swine manure under 10 % of total solids and 60 g/L of zeolite addition at 35 °C. Four distinctive volatile fatty acid (VFAs) evolution stages were observed during the anaerobic process, i.e., VFA accumulation, acetic acid (HAc) and butyric acid (HBu) utilization, propionic acid (HPr) and valeric acid (HVa) degradation, and VFA depletion. Large decreases in HAc/HBu and HPr/HVa occurred respectively at the first and second biogas peaks. Biogas yield increased by 20 % after zeolite addition, about 356 mL/g VSadded with accelerated soluble chemical oxygen demand degradation and VFA (especially HPr and HBu) consumption in addition to a shortened lag phase between the two biogas peaks. Compared with Ca(2+) and Mg(2+) (100-300 mg/L) released from zeolite, simultaneous K(+) and NH4 (+) (580-600 mg/L) adsorptions onto zeolite particles contributed more to the enhanced biogasification, resulting in alleviated inhibition effects of ammonium on acidogenesis and methanogenesis, respectively. All the identified anaerobes could be grouped into Bacteroidetes and Firmicutes, and zeolite addition had no significant influence on the microbial biodiversity in this study.

  5. Methanosarcina Play an Important Role in Anaerobic Co-Digestion of the Seaweed Ulva lactuca: Taxonomy and Predicted Metabolism of Functional Microbial Communities.

    Directory of Open Access Journals (Sweden)

    Jamie A FitzGerald

    Full Text Available Macro-algae represent an ideal resource of third generation biofuels, but their use necessitates a refinement of commonly used anaerobic digestion processes. In a previous study, contrasting mixes of dairy slurry and the macro-alga Ulva lactuca were anaerobically digested in mesophilic continuously stirred tank reactors for 40 weeks. Higher proportions of U. lactuca in the feedstock led to inhibited digestion and rapid accumulation of volatile fatty acids, requiring a reduced organic loading rate. In this study, 16S pyrosequencing was employed to characterise the microbial communities of both the weakest (R1 and strongest (R6 performing reactors from the previous work as they developed over a 39 and 27-week period respectively. Comparing the reactor communities revealed clear differences in taxonomy, predicted metabolic orientation and mechanisms of inhibition, while constrained canonical analysis (CCA showed ammonia and biogas yield to be the strongest factors differentiating the two reactor communities. Significant biomarker taxa and predicted metabolic activities were identified for viable and failing anaerobic digestion of U. lactuca. Acetoclastic methanogens were inhibited early in R1 operation, followed by a gradual decline of hydrogenotrophic methanogens. Near-total loss of methanogens led to an accumulation of acetic acid that reduced performance of R1, while a slow decline in biogas yield in R6 could be attributed to inhibition of acetogenic rather than methanogenic activity. The improved performance of R6 is likely to have been as a result of the large Methanosarcina population, which enabled rapid removal of acetic acid, providing favourable conditions for substrate degradation.

  6. Methanosarcina Play an Important Role in Anaerobic Co-Digestion of the Seaweed Ulva lactuca: Taxonomy and Predicted Metabolism of Functional Microbial Communities.

    Science.gov (United States)

    FitzGerald, Jamie A; Allen, Eoin; Wall, David M; Jackson, Stephen A; Murphy, Jerry D; Dobson, Alan D W

    2015-01-01

    Macro-algae represent an ideal resource of third generation biofuels, but their use necessitates a refinement of commonly used anaerobic digestion processes. In a previous study, contrasting mixes of dairy slurry and the macro-alga Ulva lactuca were anaerobically digested in mesophilic continuously stirred tank reactors for 40 weeks. Higher proportions of U. lactuca in the feedstock led to inhibited digestion and rapid accumulation of volatile fatty acids, requiring a reduced organic loading rate. In this study, 16S pyrosequencing was employed to characterise the microbial communities of both the weakest (R1) and strongest (R6) performing reactors from the previous work as they developed over a 39 and 27-week period respectively. Comparing the reactor communities revealed clear differences in taxonomy, predicted metabolic orientation and mechanisms of inhibition, while constrained canonical analysis (CCA) showed ammonia and biogas yield to be the strongest factors differentiating the two reactor communities. Significant biomarker taxa and predicted metabolic activities were identified for viable and failing anaerobic digestion of U. lactuca. Acetoclastic methanogens were inhibited early in R1 operation, followed by a gradual decline of hydrogenotrophic methanogens. Near-total loss of methanogens led to an accumulation of acetic acid that reduced performance of R1, while a slow decline in biogas yield in R6 could be attributed to inhibition of acetogenic rather than methanogenic activity. The improved performance of R6 is likely to have been as a result of the large Methanosarcina population, which enabled rapid removal of acetic acid, providing favourable conditions for substrate degradation.

  7. Nanoscale zero-valent iron/persulfate enhanced upflow anaerobic sludge blanket reactor for dye removal: Insight into microbial metabolism and microbial community

    Science.gov (United States)

    Pan, Fei; Zhong, Xiaohan; Xia, Dongsheng; Yin, Xianze; Li, Fan; Zhao, Dongye; Ji, Haodong; Liu, Wen

    2017-03-01

    This study investigated the efficiency of nanoscale zero-valent iron combined with persulfate (NZVI/PS) for enhanced degradation of brilliant red X-3B in an upflow anaerobic sludge blanket (UASB) reactor, and examined the effects of NZVI/PS on anaerobic microbial communities during the treatment process. The addition of NZVI (0.5 g/L) greatly enhanced the decolourization rate of X-3B from 63.8% to 98.4%. The Biolog EcoPlateTM technique was utilized to examine microbial metabolism in the reactor, and the Illumina MiSeq high-throughput sequencing revealed 22 phyla and 88 genera of the bacteria. The largest genera (Lactococcus) decreased from 33.03% to 7.94%, while the Akkermansia genera increased from 1.69% to 20.23% according to the abundance in the presence of 0.2 g/L NZVI during the biological treatment process. Meanwhile, three strains were isolated from the sludge in the UASB reactors and identified by 16 S rRNA analysis. The distribution of three strains was consistent with the results from the Illumina MiSeq high throughput sequencing. The X-ray photoelectron spectroscopy results indicated that Fe(0) was transformed into Fe(II)/Fe(III) during the treatment process, which are beneficial for the microorganism growth, and thus promoting their metabolic processes and microbial community.

  8. Nanoscale zero-valent iron/persulfate enhanced upflow anaerobic sludge blanket reactor for dye removal: Insight into microbial metabolism and microbial community

    Science.gov (United States)

    Pan, Fei; Zhong, Xiaohan; Xia, Dongsheng; Yin, Xianze; Li, Fan; Zhao, Dongye; Ji, Haodong; Liu, Wen

    2017-01-01

    This study investigated the efficiency of nanoscale zero-valent iron combined with persulfate (NZVI/PS) for enhanced degradation of brilliant red X-3B in an upflow anaerobic sludge blanket (UASB) reactor, and examined the effects of NZVI/PS on anaerobic microbial communities during the treatment process. The addition of NZVI (0.5 g/L) greatly enhanced the decolourization rate of X-3B from 63.8% to 98.4%. The Biolog EcoPlateTM technique was utilized to examine microbial metabolism in the reactor, and the Illumina MiSeq high-throughput sequencing revealed 22 phyla and 88 genera of the bacteria. The largest genera (Lactococcus) decreased from 33.03% to 7.94%, while the Akkermansia genera increased from 1.69% to 20.23% according to the abundance in the presence of 0.2 g/L NZVI during the biological treatment process. Meanwhile, three strains were isolated from the sludge in the UASB reactors and identified by 16 S rRNA analysis. The distribution of three strains was consistent with the results from the Illumina MiSeq high throughput sequencing. The X-ray photoelectron spectroscopy results indicated that Fe(0) was transformed into Fe(II)/Fe(III) during the treatment process, which are beneficial for the microorganism growth, and thus promoting their metabolic processes and microbial community. PMID:28300176

  9. Increased anaerobic metabolism is a distinctive signature in a colorectal cancer cellular model of resistance to antiepidermal growth factor receptor antibody.

    Science.gov (United States)

    Monteleone, Francesca; Rosa, Roberta; Vitale, Monica; D'Ambrosio, Chiara; Succoio, Mariangela; Formisano, Luigi; Nappi, Lucia; Romano, Maria Fiammetta; Scaloni, Andrea; Tortora, Giampaolo; Bianco, Roberto; Zambrano, Nicola

    2013-03-01

    Cetuximab is a chimeric antibody approved for the treatment of metastatic colorectal cancer that selectively targets epidermal growth factor receptor (EGFR) signaling. Treatment efficacy with this drug is often impaired by acquired resistance and poor information has been accumulated on the mechanisms underlying such a phenomenon. By taking advantage of a syngenic cellular system of sensitivity and acquired resistance to anti-EGFR therapy in the colorectal carcinoma GEO cell line, we profiled protein expression differences between Cetuximab-sensitive and -resistant cells. Combined 2D DIGE and MS analyses revealed a main proteomic signature resulting from selective deregulation of various metabolic enzymes, including glucose-6-phosphate dehydrogenase, transketolase, lactate dehydrogenase B, and pyruvate dehydrogenase E1, which was also confirmed by Western blotting experiments. Lactate dehydrogenase B downregulation has been already related to an increased anaerobic utilization of glucose by tumor cells; accordingly, we verified that Cetuximab-resistant cells have a significantly higher production of lactate. Resistant cells also showed decreased nicotinamide adenine dinucleotide phosphate (NADPH) levels. Observed protein deregulations were not related to functional alterations of the hypoxia-inducible factor 1-associated pathways. Our data demonstrate that increased anaerobic metabolism is a prominent feature observed in the GEO syngenic model of acquired resistance to anti-EGFR therapy in colorectal cancer. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Unique Microbial Diversity and Metabolic Pathway Features of Fermented Vegetables From Hainan, China

    OpenAIRE

    Qiannan Peng; Shuaiming Jiang; Jieling Chen; Chenchen Ma; Dongxue Huo; Yuyu Shao; Jiachao Zhang; Jiachao Zhang

    2018-01-01

    Fermented vegetables are typically traditional foods made of fresh vegetables and their juices, which are fermented by beneficial microorganisms. Herein, we applied high-throughput sequencing and culture-dependent technology to describe the diversities of microbiota and identify core microbiota in fermented vegetables from different areas of Hainan Province, and abundant metabolic pathways in the fermented vegetables were simultaneously predicted. At the genus level, Lactobacillus bacteria we...

  11. Phylogenetic, Metabolic, and Taxonomic Diversities Shape Mediterranean Fruit Fly Microbiotas during Ontogeny

    Science.gov (United States)

    Aharon, Yael; Pasternak, Zohar; Ben Yosef, Michael; Behar, Adi; Lauzon, Carol; Yuval, Boaz

    2013-01-01

    The Mediterranean fruit fly (medfly) (Ceratitis capitata) lays eggs in fruits, where larvae subsequently develop, causing large-scale agricultural damage. Within its digestive tract, the fly supports an extended bacterial community that is composed of multiple strains of a variety of enterobacterial species. Most of these bacteria appear to be functionally redundant, with most strains sustaining diazotrophy and/or pectinolysis. At least some of these bacteria were shown to be vertically inherited, but colonization, structural, and metabolic aspects of the community's dynamics have not been investigated. We used fluorescent in situ hybridization, metabolic profiling, plate cultures, and pyrosequencing to show that an initial, egg-borne, diverse community expands throughout the fly's life cycle. While keeping “core” diazotrophic and pectinolytic functions, it also harbors diverse and fluctuating populations that express varied metabolic capabilities. We suggest that the metabolic and compositional plasticity of the fly's microbiota provides potential adaptive advantages to the medfly host and that its acquisition and dynamics are affected by mixed processes that include stochastic effects, host behavior, and molecular barriers. PMID:23104413

  12. Unique Microbial Diversity and Metabolic Pathway Features of Fermented Vegetables From Hainan, China

    Science.gov (United States)

    Peng, Qiannan; Jiang, Shuaiming; Chen, Jieling; Ma, Chenchen; Huo, Dongxue; Shao, Yuyu; Zhang, Jiachao

    2018-01-01

    Fermented vegetables are typically traditional foods made of fresh vegetables and their juices, which are fermented by beneficial microorganisms. Herein, we applied high-throughput sequencing and culture-dependent technology to describe the diversities of microbiota and identify core microbiota in fermented vegetables from different areas of Hainan Province, and abundant metabolic pathways in the fermented vegetables were simultaneously predicted. At the genus level, Lactobacillus bacteria were the most abundant. Lactobacillus plantarum was the most abundant species, followed by Lactobacillus fermentum, Lactobacillus pentosaceus, and Weissella cibaria. These species were present in each sample with average absolute content values greater than 1% and were thus defined as core microbiota. Analysis results based on the alpha and beta diversities of the microbial communities showed that the microbial profiles of the fermented vegetables differed significantly based on the regions and raw materials used, and the species of the vegetables had a greater effect on the microbial community structure than the region from where they were harvested. Regarding microbial functional metabolism, we observed an enrichment of metabolic pathways, including membrane transport, replication and repair and translation, which implied that the microbial metabolism in the fermented vegetables tended to be vigorous. In addition, Lactobacillus plantarum and Lactobacillus fermentum were calculated to be major metabolic pathway contributors. Finally, we constructed a network to better explain correlations among the core microbiota and metabolic pathways. This study facilitates an understanding of the differences in microbial profiles and fermentation pathways involved in the production of fermented vegetables, establishes a basis for optimally selecting microorganisms to manufacture high-quality fermented vegetable products, and lays the foundation for better utilizing tropical microbial

  13. Unique Microbial Diversity and Metabolic Pathway Features of Fermented Vegetables From Hainan, China

    Directory of Open Access Journals (Sweden)

    Qiannan Peng

    2018-03-01

    Full Text Available Fermented vegetables are typically traditional foods made of fresh vegetables and their juices, which are fermented by beneficial microorganisms. Herein, we applied high-throughput sequencing and culture-dependent technology to describe the diversities of microbiota and identify core microbiota in fermented vegetables from different areas of Hainan Province, and abundant metabolic pathways in the fermented vegetables were simultaneously predicted. At the genus level, Lactobacillus bacteria were the most abundant. Lactobacillus plantarum was the most abundant species, followed by Lactobacillus fermentum, Lactobacillus pentosaceus, and Weissella cibaria. These species were present in each sample with average absolute content values greater than 1% and were thus defined as core microbiota. Analysis results based on the alpha and beta diversities of the microbial communities showed that the microbial profiles of the fermented vegetables differed significantly based on the regions and raw materials used, and the species of the vegetables had a greater effect on the microbial community structure than the region from where they were harvested. Regarding microbial functional metabolism, we observed an enrichment of metabolic pathways, including membrane transport, replication and repair and translation, which implied that the microbial metabolism in the fermented vegetables tended to be vigorous. In addition, Lactobacillus plantarum and Lactobacillus fermentum were calculated to be major metabolic pathway contributors. Finally, we constructed a network to better explain correlations among the core microbiota and metabolic pathways. This study facilitates an understanding of the differences in microbial profiles and fermentation pathways involved in the production of fermented vegetables, establishes a basis for optimally selecting microorganisms to manufacture high-quality fermented vegetable products, and lays the foundation for better utilizing

  14. Integrated Analysis of Protein Complexes and Regulatory Networks Involved in Anaerobic Energy Metabolism of Shewanella Oneidensis MR-1

    Energy Technology Data Exchange (ETDEWEB)

    Tiedje, James M.

    2005-06-01

    Anaerobic Nitrate Reduction. Nitrate is an extensive co-contaminant at some DOE sites making metal and radionuclide reduction problematic. Hence, we sought to better understand the nitrate reduction pathway and its control in S. oneidensis MR-1. It is not known whether the nitrate reduction is by denitrification or dissimilatory nitrate reduction into ammonium (DNRA). By both physiological and genetic evidence, we proved that DNRA is the nitrate reduction pathway in this organism. Using the complete genome sequence of S. oneidensis MR-1, we identified a gene encoding a periplasmic nitrate reductase based on its 72% sequence identity with the napA gene in E. coli. Anaerobic growth of MR-1 on nitrate was abolished in a site directed napA mutant, indicating that NapA is the only nitrate reductase present. The anaerobic expression of napA and nrfA, a homolog of the cytochrome b552 nitrite reductase in E. coli, increased with increasing nitrate concentration until a plateau was reached at 3 mM KNO3. This indicates that these genes are not repressed by increasing concentrations of nitrate. The reduction of nitrate can generate intermediates that can be toxic to the microorganism. To determine the genetic response of MR-1 to high concentrations of nitrate, DNA microarrays were used to obtain a complete gene expression profile of MR-1 at low (1 mM) versus high (40 mM) nitrate concentrations. Genes encoding transporters and efflux pumps were up-regulated, perhaps as a mechanism to export toxic compounds. In addition, the gene expression profile of MR-1, grown anaerobically with nitrate as the only electron acceptor, suggested that this dissimilatory pathway contributes to N assimilation. Hence the nitrate reduction pathway could serve a dual purpose. The role of EtrA, a homolog of Fnr (global anaerobic regulator in E. coli) was examined using an etrA deletion mutant we constructed, S. oneidensis EtrA7-1.

  15. Shape shifting predicts ontogenetic changes in metabolic scaling in diverse aquatic invertebrates.

    Science.gov (United States)

    Glazier, Douglas S; Hirst, Andrew G; Atkinson, David

    2015-03-07

    Metabolism fuels all biological activities, and thus understanding its variation is fundamentally important. Much of this variation is related to body size, which is commonly believed to follow a 3/4-power scaling law. However, during ontogeny, many kinds of animals and plants show marked shifts in metabolic scaling that deviate from 3/4-power scaling predicted by general models. Here, we show that in diverse aquatic invertebrates, ontogenetic shifts in the scaling of routine metabolic rate from near isometry (bR = scaling exponent approx. 1) to negative allometry (bR < 1), or the reverse, are associated with significant changes in body shape (indexed by bL = the scaling exponent of the relationship between body mass and body length). The observed inverse correlations between bR and bL are predicted by metabolic scaling theory that emphasizes resource/waste fluxes across external body surfaces, but contradict theory that emphasizes resource transport through internal networks. Geometric estimates of the scaling of surface area (SA) with body mass (bA) further show that ontogenetic shifts in bR and bA are positively correlated. These results support new metabolic scaling theory based on SA influences that may be applied to ontogenetic shifts in bR shown by many kinds of animals and plants. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  16. Genetic variation in eleven phase I drug metabolism genes in an ethnically diverse population.

    Science.gov (United States)

    Solus, Joseph F; Arietta, Brenda J; Harris, James R; Sexton, David P; Steward, John Q; McMunn, Chara; Ihrie, Patrick; Mehall, Janelle M; Edwards, Todd L; Dawson, Elliott P

    2004-10-01

    The extent of genetic variation found in drug metabolism genes and its contribution to interindividual variation in response to medication remains incompletely understood. To better determine the identity and frequency of variation in 11 phase I drug metabolism genes, the exons and flanking intronic regions of the cytochrome P450 (CYP) isoenzyme genes CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4 and CYP3A5 were amplified from genomic DNA and sequenced. A total of 60 kb of bi-directional sequence was generated from each of 93 human DNAs, which included Caucasian, African-American and Asian samples. There were 388 different polymorphisms identified. These included 269 non-coding, 45 synonymous and 74 non-synonymous polymorphisms. Of these, 54% were novel and included 176 non-coding, 14 synonymous and 21 non-synonymous polymorphisms. Of the novel variants observed, 85 were represented by single occurrences of the minor allele in the sample set. Much of the variation observed was from low-frequency alleles. Comparatively, these genes are variation-rich. Calculations measuring genetic diversity revealed that while the values for the individual genes are widely variable, the overall nucleotide diversity of 7.7 x 10(-4) and polymorphism parameter of 11.5 x 10(-4) are higher than those previously reported for other gene sets. Several independent measurements indicate that these genes are under selective pressure, particularly for polymorphisms corresponding to non-synonymous amino acid changes. There is relatively little difference in measurements of diversity among the ethnic groups, but there are large differences among the genes and gene subfamilies themselves. Of the three CYP subfamilies involved in phase I drug metabolism (1, 2, and 3), subfamily 2 displays the highest levels of genetic diversity.

  17. Metabolic analysis of the soil microbe Dechloromonas aromatica str. RCB: indications of a surprisingly complex life-style and cryptic anaerobic pathways for aromatic degradation

    Energy Technology Data Exchange (ETDEWEB)

    Salinero, Kennan Kellaris; Keller, Keith; Feil, William S.; Feil, Helene; Trong, Stephan; Di Bartolo, Genevieve; Lapidus, Alla

    2008-11-17

    Initial interest in Dechloromonas aromatica strain RCB arose from its ability to anaerobically degrade benzene. It is also able to reduce perchlorate and oxidize chlorobenzoate, toluene, and xylene, creating interest in using this organism for bioremediation. Little physiological data has been published for this microbe. It is considered to be a free-living organism. The a priori prediction that the D. aromatica genome would contain previously characterized 'central' enzymes involved in anaerobic aromatic degradation proved to be false, suggesting the presence of novel anaerobic aromatic degradation pathways in this species. These missing pathways include the benzyl succinyl synthase (bssABC) genes (responsible for formate addition to toluene) and the central benzoylCoA pathway for monoaromatics. In depth analyses using existing TIGRfam, COG, and InterPro models, and the creation of de novo HMM models, indicate a highly complex lifestyle with a large number of environmental sensors and signaling pathways, including a relatively large number of GGDEF domain signal receptors and multiple quorum sensors. A number of proteins indicate interactions with an as yet unknown host, as indicated by the presence of predicted cell host remodeling enzymes, effector enzymes, hemolysin-like proteins, adhesins, NO reductase, and both type III and type VI secretory complexes. Evidence of biofilm formation including a proposed exopolysaccharide complex with the somewhat rare exosortase (epsH), is also present. Annotation described in this paper also reveals evidence for several metabolic pathways that have yet to be observed experimentally, including a sulphur oxidation (soxFCDYZAXB) gene cluster, Calvin cycle enzymes, and nitrogen fixation (including RubisCo, ribulose-phosphate 3-epimerase, and nif gene families, respectively). Analysis of the D. aromatica genome indicates there is much to be learned regarding the metabolic capabilities, and life-style, for this microbial

  18. Metabolic analysis of the soil microbe Dechloromonas aromatica str. RCB: indications of a surprisingly complex life-style and cryptic anaerobic pathways for aromatic degradation

    Directory of Open Access Journals (Sweden)

    Feil Helene

    2009-08-01

    Full Text Available Abstract Background Initial interest in Dechloromonas aromatica strain RCB arose from its ability to anaerobically degrade benzene. It is also able to reduce perchlorate and oxidize chlorobenzoate, toluene, and xylene, creating interest in using this organism for bioremediation. Little physiological data has been published for this microbe. It is considered to be a free-living organism. Results The a priori prediction that the D. aromatica genome would contain previously characterized "central" enzymes to support anaerobic aromatic degradation of benzene proved to be false, suggesting the presence of novel anaerobic aromatic degradation pathways in this species. These missing pathways include the benzylsuccinate synthase (bssABC genes (responsible for fumarate addition to toluene and the central benzoyl-CoA pathway for monoaromatics. In depth analyses using existing TIGRfam, COG, and InterPro models, and the creation of de novo HMM models, indicate a highly complex lifestyle with a large number of environmental sensors and signaling pathways, including a relatively large number of GGDEF domain signal receptors and multiple quorum sensors. A number of proteins indicate interactions with an as yet unknown host, as indicated by the presence of predicted cell host remodeling enzymes, effector enzymes, hemolysin-like proteins, adhesins, NO reductase, and both type III and type VI secretory complexes. Evidence of biofilm formation including a proposed exopolysaccharide complex and exosortase (epsH are also present. Annotation described in this paper also reveals evidence for several metabolic pathways that have yet to be observed experimentally, including a sulphur oxidation (soxFCDYZAXB gene cluster, Calvin cycle enzymes, and proteins involved in nitrogen fixation in other species (including RubisCo, ribulose-phosphate 3-epimerase, and nif gene families, respectively. Conclusion Analysis of the D. aromatica genome indicates there is much to be

  19. Functional Gene Diversity and Metabolic Potential of the Microbial Community in an Estuary-Shelf Environment

    Directory of Open Access Journals (Sweden)

    Yu Wang

    2017-06-01

    Full Text Available Microbes play crucial roles in various biogeochemical processes in the ocean, including carbon (C, nitrogen (N, and phosphorus (P cycling. Functional gene diversity and the structure of the microbial community determines its metabolic potential and therefore its ecological function in the marine ecosystem. However, little is known about the functional gene composition and metabolic potential of bacterioplankton in estuary areas. The East China Sea (ECS is a dynamic marginal ecosystem in the western Pacific Ocean that is mainly affected by input from the Changjiang River and the Kuroshio Current. Here, using a high-throughput functional gene microarray (GeoChip, we analyzed the functional gene diversity, composition, structure, and metabolic potential of microbial assemblages in different ECS water masses. Four water masses determined by temperature and salinity relationship showed different patterns of functional gene diversity and composition. Generally, functional gene diversity [Shannon–Weaner’s H and reciprocal of Simpson’s 1/(1-D] in the surface water masses was higher than that in the bottom water masses. The different presence and proportion of functional genes involved in C, N, and P cycling among the bacteria of the different water masses showed different metabolic preferences of the microbial populations in the ECS. Genes involved in starch metabolism (amyA and nplT showed higher proportion in microbial communities of the surface water masses than of the bottom water masses. In contrast, a higher proportion of genes involved in chitin degradation was observed in microorganisms of the bottom water masses. Moreover, we found a higher proportion of nitrogen fixation (nifH, transformation of hydroxylamine to nitrite (hao and ammonification (gdh genes in the microbial communities of the bottom water masses compared with those of the surface water masses. The spatial variation of microbial functional genes was significantly correlated

  20. Anaerobic bacteria

    Science.gov (United States)

    Anaerobic bacteria are bacteria that do not live or grow when oxygen is present. In humans, these bacteria ... Brook I. Diseases caused by non-spore-forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman-Cecil ...

  1. Metabolic and cardiovascular improvements after biliopancreatic diversion in a severely obese patient

    Directory of Open Access Journals (Sweden)

    Lescelleur Odette

    2004-04-01

    Full Text Available Abstract Background Severe obesity is associated with important morbidity and increased mortality. The successes of lifestyle modifications and drug therapy have been partial and mostly unsustained in reducing obesity and its comorbidities. Bariatric surgery, particularly biliopancreatic diversion with duodenal switch reduces efficiently excess body weight and improves metabolic and cardiovascular functions. Case presentation A 56-year-old man with severe clinical obesity underwent a biliopancreatic diversion with a duodenal switch after unsuccessful treatment with weight loss pharmacotherapy. He had diabetes, hypertension and sleep apnea syndrome and was on three medications for hypertension and two hypoglycemic agents in addition to > 200 insulin units daily. Eleven months after the surgery, he had lost 40% of his body weight. The lipid profile showed great improvement and the hypertension and diabetes were more easily controlled with no more insulin needed. The pseudonormalized pattern of left ventricular diastolic function improved and ventricular walls showed decreased thickness. Conclusion Biliopancreatic diversion may bring metabolic and cardiovascular benefits in severely obese patients from a cardiovascular perspective.

  2. One carbon metabolism in anaerobic bacteria: Regulation of carbon and electron flow during organic acid production: Progress report, February 1, 1987-February 1, 1988

    International Nuclear Information System (INIS)

    Zeikus, J.G.; Shen, Gwo-Jenn.

    1988-01-01

    These studies concern the fundamental biochemical mechanisms that control carbon and electron flow in anaerobic bacteria that conserve energy when coupling hydrogen consumption to the production of acetic, propionic, or butyric acids. Two acidogens, Propionispira arboris and Butyribacterium methylotrophicum were chosen as model systems to understand the function of oxidoreductases and electron carriers in the regulation of hydrogen metabolism and single carbon metabolism. In P. arboris, H 2 consumption was linked to the inhibition of CO 2 production and an increase in the propionate/acetate rate; whereas, H 2 consumption was linked to a stimulation of CO 2 consumption and an increase in the butyrate/acetate ratio in B. methylotrophicum. We report studies on the enzymes involved in the regulation of singe carbon metabolism, the enzyme activities and pathways responsible for conversion of multicarbon components to acetate and propionate or butyrate, and how low pH inhibits H 2 and acetic acid production in Sarcina ventriculi as a consequence of hydrogenase regulation. 9 refs

  3. Metatranscriptomic analysis of diverse microbial communities reveals core metabolic pathways and microbiome-specific functionality.

    Science.gov (United States)

    Jiang, Yue; Xiong, Xuejian; Danska, Jayne; Parkinson, John

    2016-01-12

    Metatranscriptomics is emerging as a powerful technology for the functional characterization of complex microbial communities (microbiomes). Use of unbiased RNA-sequencing can reveal both the taxonomic composition and active biochemical functions of a complex microbial community. However, the lack of established reference genomes, computational tools and pipelines make analysis and interpretation of these datasets challenging. Systematic studies that compare data across microbiomes are needed to demonstrate the ability of such pipelines to deliver biologically meaningful insights on microbiome function. Here, we apply a standardized analytical pipeline to perform a comparative analysis of metatranscriptomic data from diverse microbial communities derived from mouse large intestine, cow rumen, kimchi culture, deep-sea thermal vent and permafrost. Sequence similarity searches allowed annotation of 19 to 76% of putative messenger RNA (mRNA) reads, with the highest frequency in the kimchi dataset due to its relatively low complexity and availability of closely related reference genomes. Metatranscriptomic datasets exhibited distinct taxonomic and functional signatures. From a metabolic perspective, we identified a common core of enzymes involved in amino acid, energy and nucleotide metabolism and also identified microbiome-specific pathways such as phosphonate metabolism (deep sea) and glycan degradation pathways (cow rumen). Integrating taxonomic and functional annotations within a novel visualization framework revealed the contribution of different taxa to metabolic pathways, allowing the identification of taxa that contribute unique functions. The application of a single, standard pipeline confirms that the rich taxonomic and functional diversity observed across microbiomes is not simply an artefact of different analysis pipelines but instead reflects distinct environmental influences. At the same time, our findings show how microbiome complexity and availability of

  4. Anaerobic co-digestion of chicken manure and microalgae Chlorella sp.: Methane potential, microbial diversity and synergistic impact evaluation.

    Science.gov (United States)

    Li, Ruirui; Duan, Na; Zhang, Yuanhui; Liu, Zhidan; Li, Baoming; Zhang, Dongming; Dong, Taili

    2017-10-01

    Anaerobic digestion (AD) is a promising alternative for livestock manure management. This paper presents the experimental results obtained through a batch experiment by using chicken manure (CM) and microalgae Chlorella sp. as co-substrates. The effect of co-digestion was evaluated by varying CM to Chlorella sp. ratios (0:10, 2:8, 4:6, 6:4, 8:2, 10: 0 based on the volatile solids (VS)). The major objective of this study is to evaluate the feasibility and synergistic impact of co-digestion of CM and Chlorella sp. Enhanced 14.20% and 76.86% methane production than CM and Chlorella sp. mono-digestion respectively was achieved in co-digestion at the ratio 8:2. In addition, the co-digestion at the ratio 8:2 showed significantly higher methane yield than the weighted average of the individual substrates' specific methane yield (WSMY), indicating strong synergy effect. The Illumina Miseq sequencing analysis showed that the AD process suppressed the acetoclastic methanogenesis Methanosaeta content; but partly enhanced hydrogenotrophic methanogenesis Methanosarcina, Methanospirillum and Methanobacterium, which was responsible for the methane production. The pre-treated microalgae was then introduced at the optimal ratio 8:2 to estimate the effect of pre-treatment of microalgae on AD process. However, the pre-treatment exhibited no positive effect. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Unusual metabolic diversity of hyperalkaliphilic microbial communities associated with subterranean serpentinization at The Cedars.

    Science.gov (United States)

    Suzuki, Shino; Ishii, Shun'ichi; Hoshino, Tatsuhiko; Rietze, Amanda; Tenney, Aaron; Morrill, Penny L; Inagaki, Fumio; Kuenen, J Gijs; Nealson, Kenneth H

    2017-11-01

    Water from The Cedars springs that discharge from serpentinized ultramafic rocks feature highly basic (pH=~12), highly reducing (E h serpentinizing system, was dominated by several bacterial taxa from the phyla OD1 ('Parcubacteria') and Chloroflexi. Members of the GPS1 community had, for the most part, the smallest genomes reported for their respective taxa, and encoded only archaeal (A-type) ATP synthases or no ATP synthases at all. Furthermore, none of the members encoded respiration-related genes and some of the members also did not encode key biosynthesis-related genes. In contrast, BS5, fed by shallow water, appears to have a community driven by hydrogen metabolism and was dominated by a diverse group of Proteobacteria similar to those seen in many terrestrial serpentinization sites. Our findings indicated that the harsh ultrabasic geological setting supported unexpectedly diverse microbial metabolic strategies and that the deep-water-fed springs supported a community that was remarkable in its unusual metagenomic and genomic constitution.

  6. Endophytic actinobacteria: Diversity, secondary metabolism and mechanisms to unsilence biosynthetic gene clusters.

    Science.gov (United States)

    Dinesh, Raghavan; Srinivasan, Veeraraghavan; T E, Sheeja; Anandaraj, Muthuswamy; Srambikkal, Hamza

    2017-09-01

    Endophytic actinobacteria, which reside in the inner tissues of host plants, are gaining serious attention due to their capacity to produce a plethora of secondary metabolites (e.g. antibiotics) possessing a wide variety of biological activity with diverse functions. This review encompasses the recent reports on endophytic actinobacterial species diversity, in planta habitats and mechanisms underlying their mode of entry into plants. Besides, their metabolic potential, novel bioactive compounds they produce and mechanisms to unravel their hidden metabolic repertoire by activation of cryptic or silent biosynthetic gene clusters (BGCs) for eliciting novel secondary metabolite production are discussed. The study also reviews the classical conservative techniques (chemical/biological/physical elicitation, co-culturing) as well as modern microbiology tools (e.g. next generation sequencing) that are being gainfully employed to uncover the vast hidden scaffolds for novel secondary metabolites produced by these endophytes, which would subsequently herald a revolution in drug engineering. The potential role of these endophytes in the agro-environment as promising biological candidates for inhibition of phytopathogens and the way forward to thoroughly exploit this unique microbial community by inducing expression of cryptic BGCs for encoding unseen products with novel therapeutic properties are also discussed.

  7. Molecular genetic studies on obligate anaerobic bacteria

    International Nuclear Information System (INIS)

    Woods, D.R.

    1982-01-01

    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

  8. Gancao-Gansui combination impacts gut microbiota diversity and related metabolic functions.

    Science.gov (United States)

    Yu, Jingao; Guo, Jianming; Tao, Weiwei; Liu, Pei; Shang, Erxin; Zhu, Zhenhua; Fan, Xiuhe; Shen, Juan; Hua, Yongqing; Zhu, Kevin Yue; Tang, Yuping; Duan, Jin-Ao

    2018-03-25

    The theory of "eighteen incompatible medicaments" (EIM) in traditional Chinese medicine (TCM) is the most representative case of herbal-herbal interactions. Gancao and Gansui are one of the incompatible herbal pairs in EIM. Gancao, also known as "licorice", is the most frequently used Chinese herb or food additive. Gansui, the root of Euphorbia kansui T.P. Wang, is another famous Chinese herb usually used to treat edema, ascites and asthma but could induce gastrointestinal (GI) tract irritation. Although Gancao and Gansui are incompatible herbal pairs, they are still used in combination in the famous "Gansui-Banxia" decoction. This study was conducted to investigate if Gancao-Gansui combination could exacerbate Gansui induced GI tract injury. Moreover, the impact of Gancao-Gansui combination to gut microbiota and related metabolism pathways were evaluated. Normal mice were divided into different groups and treated with Gancao extracts, Gansui extracts, and Gancao-Gansui combination extracts for 7 days. Serum biomarkers (diamine oxidase activity, lipopolysaccharide, motilin, IL-1β, IL-6, TNF-α) were determined to reflect GI tract damage. Gut microbiota diversity was studied by 16S rDNA sequencing and metagenomes analysis were also conducted to reflect functional genes expression alteration. Fecal hydrogen sulfide concentrations were measured by spectrophotometry to confirm the alteration of Desulfovibrio genus. Fecal lipid metabolomics study was conducted by GC-MS analysis to confirm the change of metagenomes and Mycoplasma abundance. Gancao-Gansui combination did not exacerbate GI tract tissue or functional damage but caused gut microbiota dysbiosis and increased some rare genus's abundance including Desulfovibrio and Mycoplasma. Desulfovibrio genus proliferation was confirmed by the disturbance of fecal hydrogen sulfide homeostasis. Gancao-Gansui combination also dys-regulated the metabolic genes in metagenomes. Mycoplasma genus proliferation and the metagenomes

  9. Increments and duplication events of enzymes and transcription factors influence metabolic and regulatory diversity in prokaryotes.

    Directory of Open Access Journals (Sweden)

    Mario Alberto Martínez-Núñez

    Full Text Available In this work, the content of enzymes and DNA-binding transcription factors (TFs in 794 non-redundant prokaryotic genomes was evaluated. The identification of enzymes was based on annotations deposited in the KEGG database as well as in databases of functional domains (COG and PFAM and structural domains (Superfamily. For identifications of the TFs, hidden Markov profiles were constructed based on well-known transcriptional regulatory families. From these analyses, we obtained diverse and interesting results, such as the negative rate of incremental changes in the number of detected enzymes with respect to the genome size. On the contrary, for TFs the rate incremented as the complexity of genome increased. This inverse related performance shapes the diversity of metabolic and regulatory networks and impacts the availability of enzymes and TFs. Furthermore, the intersection of the derivatives between enzymes and TFs was identified at 9,659 genes, after this point, the regulatory complexity grows faster than metabolic complexity. In addition, TFs have a low number of duplications, in contrast to the apparent high number of duplications associated with enzymes. Despite the greater number of duplicated enzymes versus TFs, the increment by which duplicates appear is higher in TFs. A lower proportion of enzymes among archaeal genomes (22% than in the bacterial ones (27% was also found. This low proportion might be compensated by the interconnection between the metabolic pathways in Archaea. A similar proportion was also found for the archaeal TFs, for which the formation of regulatory complexes has been proposed. Finally, an enrichment of multifunctional enzymes in Bacteria, as a mechanism of ecological adaptation, was detected.

  10. Anaerobic exercise - Induced changes in serum mineral ...

    African Journals Online (AJOL)

    Anaerobic exercise, a non 02 – dependent energy metabolism leads to transient metabolic changes, which are corrected gradually by homestatic mechanism. We investigated in eight male subjects, the effects of anaerobic exercise after a day sedentary activity on serum mineral concentration. There was significant ...

  11. Effect of biowaste sludge maturation on the diversity of thermophilic bacteria and archaea in an anaerobic reactor.

    Science.gov (United States)

    Goberna, M; Insam, H; Franke-Whittle, I H

    2009-04-01

    Prokaryotic diversity was investigated near the inlet and outlet of a plug-flow reactor. After analyzing 800 clones, 50 bacterial and 3 archaeal phylogenetic groups were defined. Clostridia (>92%) dominated among bacteria and Methanoculleus (>90%) among archaea. Significant changes in pH and volatile fatty acids did not invoke a major shift in the phylogenetic groups. We suggest that the environmental filter imposed by the saline conditions (20 g liter(-1)) selected a stable community of halotolerant and halophilic prokaryotes.

  12. Use of metabolic inhibitors to estimate protozooplankton grazing and bacterial production in a monomictic eutrophic lake with an anaerobic hypolimnion

    International Nuclear Information System (INIS)

    Sanders, R.W.; Porter, K.G.

    1986-01-01

    Inhibitors of eucaryotes (cycloheximide and amphotericin B) and procaryotes (penicillin and chloramphenical) were used to estimate bacterivory and bacterial production in a eutrophic lake. Bacterial production appeared to be slightly greater than protozoan grazing in the aerobic waters of Lake Oglethorpe. Use of penicillin and cycloheximide yielded inconsistent results in anaerobic water and in aerobic water when bacterial production was low. Production measured by inhibiting eucaryotes with cycloheximide did not always agree with [ 3 H]thymidine estimates or differential filtration methods. Laboratory experiments showed that several common freshwater protozoans continued to swim and ingest bacterium-size latex beads in the presence of the eucaryote inhibitor. Penicillin also affected grazing rates of some ciliates. The authors recommended that caution and a corroborating method be used when estimating ecologically important parameters with specific inhibitors

  13. Gender difference of metabolic syndrome and its association with dietary diversity at different ages.

    Science.gov (United States)

    Tian, Xu; Xu, Xiaohui; Zhang, Kai; Wang, Hui

    2017-09-26

    Previous research indicated that dietary diversity had favorable association with metabolic syndrome (MetS), and it has not been investigated in China. Adults (aged 18+) with complete dietary and biochemical data were collected from 2009 China Health and Nutrition Survey ( n =4308). Dietary diversity was measured by modified Dietary Diversity Score (DDS). MetS was defined by the harmonized criteria. The association between DDS and MetS was investigated by multivariable adjusted logistic regression. An inverse-U shape relationship between MetS risk and age was detected for both genders, and female were more vulnerable than male at old times. More diversified diet decreased the risk of MetS for young female (≥18 & ≤45), similar trends were detected in serum TGs, abdominal adiposity, blood pressure, and fasting blood glucose (all P 60) and male adults (>45&≤60). Greater DDS was associated with higher serum TGs, and lower HDL-C level for male adults, higher blood pressure for old men, but lower blood pressure and fasting blood glucose in young men (all P <0.05). Male adults and old female had the highest risk of getting MetS. More diversified diet decreased MetS risk for young female, but increased the risk for male adults and old female.

  14. 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

  15. Metagenomic analysis revealed highly diverse microbial arsenic metabolism genes in paddy soils with low-arsenic contents

    International Nuclear Information System (INIS)

    Xiao, Ke-Qing; Li, Li-Guan; Ma, Li-Ping; Zhang, Si-Yu; Bao, Peng; Zhang, Tong; Zhu, Yong-Guan

    2016-01-01

    Microbe-mediated arsenic (As) metabolism plays a critical role in global As cycle, and As metabolism involves different types of genes encoding proteins facilitating its biotransformation and transportation processes. Here, we used metagenomic analysis based on high-throughput sequencing and constructed As metabolism protein databases to analyze As metabolism genes in five paddy soils with low-As contents. The results showed that highly diverse As metabolism genes were present in these paddy soils, with varied abundances and distribution for different types and subtypes of these genes. Arsenate reduction genes (ars) dominated in all soil samples, and significant correlation existed between the abundance of arr (arsenate respiration), aio (arsenite oxidation), and arsM (arsenite methylation) genes, indicating the co-existence and close-relation of different As resistance systems of microbes in wetland environments similar to these paddy soils after long-term evolution. Among all soil parameters, pH was an important factor controlling the distribution of As metabolism gene in five paddy soils (p = 0.018). To the best of our knowledge, this is the first study using high-throughput sequencing and metagenomics approach in characterizing As metabolism genes in the five paddy soil, showing their great potential in As biotransformation, and therefore in mitigating arsenic risk to humans. - Highlights: • Use metagenomics to analyze As metabolism genes in paddy soils with low-As content. • These genes were ubiquitous, abundant, and associated with diverse microbes. • pH as an important factor controlling their distribution in paddy soil. • Imply combinational effect of evolution and selection on As metabolism genes. - Metagenomics was used to analyze As metabolism genes in paddy soils with low-As contents. These genes were ubiquitous, abundant, and associated with diverse microbes.

  16. Prokaryotic diversity and dynamics in a full-scale municipal solid waste anaerobic reactor from start-up to steady-state conditions.

    Science.gov (United States)

    Cardinali-Rezende, Juliana; Colturato, Luís F D B; Colturato, Thiago D B; Chartone-Souza, Edmar; Nascimento, Andréa M A; Sanz, José L

    2012-09-01

    The prokaryotic diversity of an anaerobic reactor for the treatment of municipal solid waste was investigated over the course of 2 years with the use of 16S rDNA-targeted molecular approaches. The fermentative Bacteroidetes and Firmicutes predominated, and Proteobacteria, Actinobacteria, Tenericutes and the candidate division WWE1 were also identified. Methane production was dominated by the hydrogenotrophic Methanomicrobiales (Methanoculleus sp.) and their syntrophic association with acetate-utilizing and propionate-oxidizing bacteria. qPCR demonstrated the predominance of the hydrogenotrophic over aceticlastic Methanosarcinaceae (Methanosarcina sp. and Methanimicrococcus sp.), and Methanosaetaceae (Methanosaeta sp.) were measured in low numbers in the reactor. According to the FISH and CARD-FISH analyses, Bacteria and Archaea accounted for 85% and 15% of the cells, respectively. Different cell counts for these domains were obtained by qPCR versus FISH analyses. The use of several molecular tools increases our knowledge of the prokaryotic community dynamics from start-up to steady-state conditions in a full-scale MSW reactor. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2016-07-01

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

  18. Microbial diversity arising from thermodynamic constraints

    Science.gov (United States)

    Großkopf, Tobias; Soyer, Orkun S

    2016-01-01

    The microbial world displays an immense taxonomic diversity. This diversity is manifested also in a multitude of metabolic pathways that can utilise different substrates and produce different products. Here, we propose that these observations directly link to thermodynamic constraints that inherently arise from the metabolic basis of microbial growth. We show that thermodynamic constraints can enable coexistence of microbes that utilise the same substrate but produce different end products. We find that this thermodynamics-driven emergence of diversity is most relevant for metabolic conversions with low free energy as seen for example under anaerobic conditions, where population dynamics is governed by thermodynamic effects rather than kinetic factors such as substrate uptake rates. These findings provide a general understanding of the microbial diversity based on the first principles of thermodynamics. As such they provide a thermodynamics-based framework for explaining the observed microbial diversity in different natural and synthetic environments. PMID:27035705

  19. Microbial diversity arising from thermodynamic constraints.

    Science.gov (United States)

    Großkopf, Tobias; Soyer, Orkun S

    2016-11-01

    The microbial world displays an immense taxonomic diversity. This diversity is manifested also in a multitude of metabolic pathways that can utilise different substrates and produce different products. Here, we propose that these observations directly link to thermodynamic constraints that inherently arise from the metabolic basis of microbial growth. We show that thermodynamic constraints can enable coexistence of microbes that utilise the same substrate but produce different end products. We find that this thermodynamics-driven emergence of diversity is most relevant for metabolic conversions with low free energy as seen for example under anaerobic conditions, where population dynamics is governed by thermodynamic effects rather than kinetic factors such as substrate uptake rates. These findings provide a general understanding of the microbial diversity based on the first principles of thermodynamics. As such they provide a thermodynamics-based framework for explaining the observed microbial diversity in different natural and synthetic environments.

  20. The role of peroxisomes in the integration of metabolism and evolutionary diversity of photosynthetic organisms

    DEFF Research Database (Denmark)

    Igamberdiev, A.U.; Lea, P.J.

    2002-01-01

    reactions to flavin-dependent oxidation, coupled to the decomposition of hydrogen peroxide by catalase. Hydrogen peroxide and superoxide originating in peroxisomes are important mediators in signal transduction pathways, particularly those involving salicylic acid. By contributing to the synthesis...... of oxalate, formate and other organic acids, peroxisomes regulate major fluxes of primary and secondary metabolism. The evolutionary diversity of algae has led to the presence of a wide range of enzymes in the peroxisomes that acre only similar to higher plants in their direct predecessors, the Charophyceae....... The appearance of seed plants was connected to the acquirement by storage tissues, of a peroxisomal fatty acid oxidation function linked to the glyoxylate cycle, which is induced during seed germination and maturation. Rearrangement of the peroxisomal photorespiratory function between different tissues of higher...

  1. Diversity

    Science.gov (United States)

    Portraits In Courage Vol. VIII Portraits In Courage Vol. IX Portraits In Courage Vol. X AF Sites Social -Wide Initiative to Promote Diversity and Inclusion in the Federal Workforce Executive Order 13548 : Virtual Diversity Conference Air Force Diversity & Inclusion Air Force Diversity Graphic There is no

  2. Diversity, metabolism and microbial ecology of butyrate-producing bacteria from the human large intestine.

    Science.gov (United States)

    Louis, Petra; Flint, Harry J

    2009-05-01

    Butyrate-producing bacteria play a key role in colonic health in humans. This review provides an overview of the current knowledge of the diversity, metabolism and microbial ecology of this functionally important group of bacteria. Human colonic butyrate producers are Gram-positive firmicutes, but are phylogenetically diverse, with the two most abundant groups related to Eubacterium rectale/Roseburia spp. and to Faecalibacterium prausnitzii. Five different arrangements have been identified for the genes of the central pathway involved in butyrate synthesis, while in most cases butyryl-CoA : acetate CoA-transferase, rather than butyrate kinase, appears to perform the final step in butyrate synthesis. Mechanisms have been proposed recently in non-gut Clostridium spp. whereby butyrate synthesis can result in energy generation via both substrate-level phosphorylation and proton gradients. Here we suggest that these mechanisms also apply to the majority of butyrate producers from the human colon. The roles of these bacteria in the gut community and their influence on health are now being uncovered, taking advantage of the availability of cultured isolates and molecular methodologies. Populations of F. prausnitzii are reported to be decreased in Crohn's disease, for example, while populations of Roseburia relatives appear to be particularly sensitive to the diet composition in human volunteer studies.

  3. [Effects of nitrogen application rate on faba bean fusarium wilt and rhizospheric microbial metabolic functional diversity].

    Science.gov (United States)

    Dong, Yan; Yang, Zhi-xian; Dong, Kun; Tang, Li; Zheng, Yi; Hu, Guo-bin

    2013-04-01

    A field plot experiment was conducted to study the effects of different nitrogen (N) application rates on the microbial functional diversity in faba bean rhizosphere and the relationships between the microbial functional diversity and the occurrence of faba bean fusarium wilt. Four nitrogen application rates were installed, i. e. , N0(0 kg hm-2 , N1 (56. 25 kg hm-2) , N2(112. 5 kg hm-2), and N3 (168.75 kg hm-2), and Biolog microbial analysis system was applied to study the damage of faba bean fusarium wilt and the rhizospheric microbial metabolic functional diversity. Applying N (N1 N2, and N3) decreased the disease index of faba bean fusarium wilt and the quantity of Fusarium oxysporum significantly, and increased the quantities of bacteria and actinomyces and the ratios of bacteria/fungi and actinomyces/fungi significantly, with the peak values of bacteria and actinomyces, bacteria/fungi, and actinomyces/fungi, and the lowest disease index and F. oxysporum density in N2. As compared with N0, applying N increased the AWCD value significantly, but the effects of different N application rates on the ability of rhizospheric microbes in utilizing six types of carbon sources had definite differences. Under the application of N, the utilization rates of carbohydrates, carboxylic acids, and amino acids by the rhizospheric microbes were higher. Principal component analysis demonstrated that applying N changed the rhizospheric microbial community composition obviously, and the carbohydrates, carboxylic acids, and amino acids were the sensitive carbon sources differentiating the changes of the microbial community induced by N application. Applying N inhibited the utilization of carbohydrates and carboxylic acids but improved the utilization of amino acids and phenolic acids by the rhizospheric microbes, which could be one of the main reasons of applying N being able to reduce the harm of faba bean fusarium wilt. It was suggested that rationally applying N could increase the

  4. Establishment and metabolic analysis of a model microbial community for understanding trophic and electron accepting interactions of subsurface anaerobic environments

    Directory of Open Access Journals (Sweden)

    Yang Zamin K

    2010-05-01

    Full Text Available Abstract Background Communities of microorganisms control the rates of key biogeochemical cycles, and are important for biotechnology, bioremediation, and industrial microbiological processes. For this reason, we constructed a model microbial community comprised of three species dependent on trophic interactions. The three species microbial community was comprised of Clostridium cellulolyticum, Desulfovibrio vulgaris Hildenborough, and Geobacter sulfurreducens and was grown under continuous culture conditions. Cellobiose served as the carbon and energy source for C. cellulolyticum, whereas D. vulgaris and G. sulfurreducens derived carbon and energy from the metabolic products of cellobiose fermentation and were provided with sulfate and fumarate respectively as electron acceptors. Results qPCR monitoring of the culture revealed C. cellulolyticum to be dominant as expected and confirmed the presence of D. vulgaris and G. sulfurreducens. Proposed metabolic modeling of carbon and electron flow of the three-species community indicated that the growth of C. cellulolyticum and D. vulgaris were electron donor limited whereas G. sulfurreducens was electron acceptor limited. Conclusions The results demonstrate that C. cellulolyticum, D. vulgaris, and G. sulfurreducens can be grown in coculture in a continuous culture system in which D. vulgaris and G. sulfurreducens are dependent upon the metabolic byproducts of C. cellulolyticum for nutrients. This represents a step towards developing a tractable model ecosystem comprised of members representing the functional groups of a trophic network.

  5. Dietary diversity score is associated with cardiovascular risk factors and serum adiponectin concentrations in patients with metabolic syndrome.

    Science.gov (United States)

    Farhangi, Mahdieh Abbasalizad; Jahangiry, Leila

    2018-04-17

    Metabolic syndrome is associated with cardio-metabolic risk factors and lipid abnormalities. Previous studies evaluated the dietary habits and nutrient intakes among patients with metabolic syndrome; however the association between metabolic risk factors and adiponectin with dietary diversity score (DDS) in patients with metabolic syndrome has not been evaluated yet. Therefore the aim of the current study was to evaluate these relationships among patients with metabolic syndrome. One hundred sixty patients with metabolic syndrome were recruited in the study. The anthropometric parameters including weight, height, waist circumference and hip circumference were measured. Serum adiponectin concentration was measured by enzyme- linked immunosorbent assay method (ELISA). Lipid profile and fasting serum glucose concentrations (FSG) were also measured with enzymatic colorimetric methods. Blood pressure was also measured and DDS was calculated using the data obtained from food frequency questionnaire (FFQ). Subjects in lower DDS categorizes had significantly lower energy and fiber intake; whereas mean protein intake of subjects in the highest quartile was significantly higher than second quartile. Higher prevalence of obesity was also observed in the top quartiles (P metabolic syndrome components among patients in lower DDS quartiles was significantly higher (P metabolic syndrome. However, for further confirming the findings, more studies are warranted.

  6. Genome-scale comparison and constraint-based metabolic reconstruction of the facultative anaerobic Fe(III-reducer Rhodoferax ferrireducens

    Directory of Open Access Journals (Sweden)

    Daugherty Sean

    2009-09-01

    Full Text Available Abstract Background Rhodoferax ferrireducens is a metabolically versatile, Fe(III-reducing, subsurface microorganism that is likely to play an important role in the carbon and metal cycles in the subsurface. It also has the unique ability to convert sugars to electricity, oxidizing the sugars to carbon dioxide with quantitative electron transfer to graphite electrodes in microbial fuel cells. In order to expand our limited knowledge about R. ferrireducens, the complete genome sequence of this organism was further annotated and then the physiology of R. ferrireducens was investigated with a constraint-based, genome-scale in silico metabolic model and laboratory studies. Results The iterative modeling and experimental approach unveiled exciting, previously unknown physiological features, including an expanded range of substrates that support growth, such as cellobiose and citrate, and provided additional insights into important features such as the stoichiometry of the electron transport chain and the ability to grow via fumarate dismutation. Further analysis explained why R. ferrireducens is unable to grow via photosynthesis or fermentation of sugars like other members of this genus and uncovered novel genes for benzoate metabolism. The genome also revealed that R. ferrireducens is well-adapted for growth in the subsurface because it appears to be capable of dealing with a number of environmental insults, including heavy metals, aromatic compounds, nutrient limitation and oxidative stress. Conclusion This study demonstrates that combining genome-scale modeling with the annotation of a new genome sequence can guide experimental studies and accelerate the understanding of the physiology of under-studied yet environmentally relevant microorganisms.

  7. Diversity of Metabolically Active Bacteria in Water-Flooded High-Temperature Heavy Oil Reservoir

    Directory of Open Access Journals (Sweden)

    Tamara N. Nazina

    2017-04-01

    Full Text Available The goal of this work was to study the overall genomic diversity of microorganisms of the Dagang high-temperature oilfield (PRC and to characterize the metabolically active fraction of these populations. At this water-flooded oilfield, the microbial community of formation water from the near-bottom zone of an injection well where the most active microbial processes of oil degradation occur was investigated using molecular, cultural, radiotracer, and physicochemical techniques. The samples of microbial DNA and RNA from back-flushed water were used to obtain the clone libraries for the 16S rRNA gene and cDNA of 16S rRNA, respectively. The DNA-derived clone libraries were found to contain bacterial and archaeal 16S rRNA genes and the alkB genes encoding alkane monooxygenases similar to those encoded by alkB-geo1 and alkB-geo6 of geobacilli. The 16S rRNA genes of methanogens (Methanomethylovorans, Methanoculleus, Methanolinea, Methanothrix, and Methanocalculus were predominant in the DNA-derived library of Archaea cloned sequences; among the bacterial sequences, the 16S rRNA genes of members of the genus Geobacillus were the most numerous. The RNA-derived library contained only bacterial cDNA of the 16S rRNA sequences belonging to metabolically active aerobic organotrophic bacteria (Tepidimonas, Pseudomonas, Acinetobacter, as well as of denitrifying (Azoarcus, Tepidiphilus, Calditerrivibrio, fermenting (Bellilinea, iron-reducing (Geobacter, and sulfate- and sulfur-reducing bacteria (Desulfomicrobium, Desulfuromonas. The presence of the microorganisms of the main functional groups revealed by molecular techniques was confirmed by the results of cultural, radioisotope, and geochemical research. Functioning of the mesophilic and thermophilic branches was shown for the microbial food chain of the near-bottom zone of the injection well, which included the microorganisms of the carbon, sulfur, iron, and nitrogen cycles.

  8. 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 for these ......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...

  9. Sublethal Concentrations of Antibiotics Cause Shift to Anaerobic Metabolism in Listeria monocytogenes and Induce Phenotypes Linked to Antibiotic Tolerance

    DEFF Research Database (Denmark)

    Knudsen, Gitte Maegaard; Fromberg, Arvid; Ng, Yin

    2016-01-01

    The human pathogenic bacterium Listeria monocytogenes is exposed to antibiotics both during clinical treatment and in its saprophytic lifestyle. As one of the keys to successful treatment is continued antibiotic sensitivity, the purpose of this study was to determine if exposure to sublethal...... antibiotic concentrations would affect the bacterial physiology and induce antibiotic tolerance. Transcriptomic analyses demonstrated that each of the four antibiotics tested caused an antibiotic-specific gene expression pattern related to mode-of-action of the particular antibiotic. All four antibiotics...... in Imo1179 (eutE) encoding an aldehyde oxidoreductase where rerouting caused increased ethanol production was tolerant to three of four antibiotics tested. This shift in metabolism could be a survival strategy in response to antibiotics to avoid generation of ROS production from respiration by oxidation...

  10. Culturable prokaryotic diversity of deep, gas hydrate sediments: first use of a continuous high-pressure, anaerobic, enrichment and isolation system for subseafloor sediments (DeepIsoBUG)

    OpenAIRE

    Parkes, R John; Sellek, Gerard; Webster, Gordon; Martin, Derek; Anders, Erik; Weightman, Andrew J; Sass, Henrik

    2009-01-01

    Deep subseafloor sediments may contain depressurization-sensitive, anaerobic, piezophilic prokaryotes. To test this we developed the DeepIsoBUG system, which when coupled with the HYACINTH pressure-retaining drilling and core storage system and the PRESS core cutting and processing system, enables deep sediments to be handled without depressurization (up to 25 MPa) and anaerobic prokaryotic enrichments and isolation to be conducted up to 100 MPa. Here, we describe the system and its first use...

  11. Aiptasia as a model to study metabolic diversity and specificity in cnidarian-dinoflagellate symbioses

    KAUST Repository

    Raedecker, Nils

    2017-11-23

    The symbiosis between cnidarian hosts and microalgae of the genus Symbiodinium provides the foundation of coral reefs in oligotrophic waters. Understanding the nutrient-exchange between these partners is key to identifying the fundamental mechanisms behind this symbiosis. However, deciphering the individual role of host and algal partners in the uptake and cycling of nutrients has proven difficult, given the endosymbiotic nature of this relationship. In this study, we highlight the advantages of the emerging model system Aiptasia to investigate the metabolic diversity and specificity of cnidarian-dinoflagellate symbiosis. For this, we combined traditional measurements with nano-scale secondary ion mass spectrometry (NanoSIMS) and stable isotope labeling to investigate carbon and nitrogen cycling both at the organismal scale and the cellular scale. Our results suggest that the individual nutrient assimilation by hosts and symbionts depends on the identity of their respective symbiotic partner. Further, δ13C enrichment patterns revealed that alterations in carbon fixation rates only affected carbon assimilation in the cnidarian host but not the algal symbiont, suggesting a \\'selfish\\' character of this symbiotic association. Based on our findings, we identify new venues for future research regarding the role and regulation of nutrient exchange in the cnidarian-dinoflagellate symbiosis. In this context, the model system approach outlined in this study constitutes a powerful tool set to address these questions.

  12. Diversity and metabolic potential of the microbiota associated with a soil arthropod.

    Science.gov (United States)

    Bahrndorff, Simon; de Jonge, Nadieh; Hansen, Jacob Kjerulf; Lauritzen, Jannik Mørk Skovgaard; Spanggaard, Lasse Holt; Sørensen, Mathias Hamann; Yde, Morten; Nielsen, Jeppe Lund

    2018-02-06

    Springtails are important members of the soil fauna and play a key role in plant litter decomposition, for example through stimulation of the microbial activity. However, their interaction with soil microorganisms remains poorly understood and it is unclear which microorganisms are associated to the springtail (endo) microbiota. Therefore, we assessed the structure of the microbiota of the springtail Orchesella cincta (L.) using 16S rRNA gene amplicon sequencing. Individuals were sampled across sites in the field and the microbiota and in particular the endomicrobiota were investigated. The microbiota was dominated by the families of Rickettsiaceae, Enterobacteriaceae and Comamonadaceae and at the genus level the most abundant genera included Rickettsia, Chryseobacterium, Pseudomonas, and Stenotrophomonas. Microbial communities were distinct for the interior of the springtails for measures of community diversity and exhibited structure according to collection sites. Functional analysis of the springtail bacterial community suggests that abundant members of the microbiota may be associated with metabolism including decomposition processes. Together these results add to the understanding of the microbiota of springtails and interaction with soil microorganisms including their putative functional roles.

  13. Aiptasia as a model to study metabolic diversity and specificity in cnidarian-dinoflagellate symbioses

    KAUST Repository

    Raedecker, Nils; Raina, Jean-Baptiste; Pernice, Mathieu; Perna, Gabriela; Guagliardo, Paul; Killburn, Matt; Aranda, Manuel; Voolstra, Christian R.

    2017-01-01

    The symbiosis between cnidarian hosts and microalgae of the genus Symbiodinium provides the foundation of coral reefs in oligotrophic waters. Understanding the nutrient-exchange between these partners is key to identifying the fundamental mechanisms behind this symbiosis. However, deciphering the individual role of host and algal partners in the uptake and cycling of nutrients has proven difficult, given the endosymbiotic nature of this relationship. In this study, we highlight the advantages of the emerging model system Aiptasia to investigate the metabolic diversity and specificity of cnidarian-dinoflagellate symbiosis. For this, we combined traditional measurements with nano-scale secondary ion mass spectrometry (NanoSIMS) and stable isotope labeling to investigate carbon and nitrogen cycling both at the organismal scale and the cellular scale. Our results suggest that the individual nutrient assimilation by hosts and symbionts depends on the identity of their respective symbiotic partner. Further, δ13C enrichment patterns revealed that alterations in carbon fixation rates only affected carbon assimilation in the cnidarian host but not the algal symbiont, suggesting a 'selfish' character of this symbiotic association. Based on our findings, we identify new venues for future research regarding the role and regulation of nutrient exchange in the cnidarian-dinoflagellate symbiosis. In this context, the model system approach outlined in this study constitutes a powerful tool set to address these questions.

  14. Best-fitting prediction equations for basal metabolic rate: informing obesity interventions in diverse populations.

    Science.gov (United States)

    Sabounchi, N S; Rahmandad, H; Ammerman, A

    2013-10-01

    Basal metabolic rate (BMR) represents the largest component of total energy expenditure and is a major contributor to energy balance. Therefore, accurately estimating BMR is critical for developing rigorous obesity prevention and control strategies. Over the past several decades, numerous BMR formulas have been developed targeted to different population groups. A comprehensive literature search revealed 248 BMR estimation equations developed using diverse ranges of age, gender, race, fat-free mass, fat mass, height, waist-to-hip ratio, body mass index and weight. A subset of 47 studies included enough detail to allow for development of meta-regression equations. Utilizing these studies, meta-equations were developed targeted to 20 specific population groups. This review provides a comprehensive summary of available BMR equations and an estimate of their accuracy. An accompanying online BMR prediction tool (available at http://www.sdl.ise.vt.edu/tutorials.html) was developed to automatically estimate BMR based on the most appropriate equation after user-entry of individual age, race, gender and weight.

  15. Genome-level comparisons provide insight into the phylogeny and metabolic diversity of species within the genus Lactococcus.

    Science.gov (United States)

    Yu, Jie; Song, Yuqin; Ren, Yan; Qing, Yanting; Liu, Wenjun; Sun, Zhihong

    2017-11-03

    The genomic diversity of different species within the genus Lactococcus and the relationships between genomic differentiation and environmental factors remain unclear. In this study, type isolates of ten Lactococcus species/subspecies were sequenced to assess their genomic characteristics, metabolic diversity, and phylogenetic relationships. The total genome sizes varied between 1.99 (Lactococcus plantarum) and 2.46 megabases (Mb; L. lactis subsp. lactis), and the G + C content ranged from 34.81 (L. lactis subsp. hordniae) to 39.67% (L. raffinolactis) with an average value of 37.02%. Analysis of genome dynamics indicated that the genus Lactococcus has an open pan-genome, while the core genome size decreased with sequential addition at the genus and species group levels. A phylogenetic dendrogram based on the concatenated amino acid sequences of 643 core genes was largely consistent with the phylogenetic tree obtained by 16S ribosomal RNA (rRNA) genes, but it provided a more robust phylogenetic resolution than the 16S rRNA gene-based analysis. Comparative genomics indicated that species in the genus Lactococcus had high degrees of diversity in genome size, gene content, and carbohydrate metabolism. This may be important for the specific adaptations that allow different Lactococcus species to survive in different environments. These results provide a quantitative basis for understanding the genomic and metabolic diversity within the genus Lactococcus, laying the foundation for future studies on taxonomy and functional genomics.

  16. 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.

  17. Vertical profiles of community abundance and diversity of anaerobic methanotrophic archaea (ANME) and bacteria in a simple waste landfill in north China.

    Science.gov (United States)

    Dong, Jun; Ding, Linjie; Wang, Xu; Chi, Zifang; Lei, Jiansen

    2015-03-01

    Anaerobic methane oxidation (AMO) is considered to be an important sink of CH4 in habitats as marine sediments. But, few studies focused on AMO in landfills which may be an important sink of CH4 derived from waste fermentation. To show evidence of AMO and to uncover function anaerobic methanotroph (ANME) community in landfill, different age waste samples were collected in Jinqianpu landfill located in north China. Through high-throughput sequencing, Methanomicrobiales and Methanosarcinales archaea associated with ANME and reverse methanogenic archaea of Methanosarcina and Methanobacterium were detected. Sulfate-reducing bacteria (SRB) (Desulfobulbus and Desulfococcus) which could couple with ANME-conducting AMO were also found. But, the community structure of ANME had no significant difference with depths. From the results of investigation, we can come to a conclusion that sulfate-dependent anaerobic methane oxidation (SR-DAMO) would be the dominant AMO process in the landfill, while iron-dependent anaerobic methane oxidation (M/IR-DAMO) process was weak though concentration of ferric iron was large in the landfill. Denitrification-dependent anaerobic methane oxidation (NR-DAMO) was negative because of lack of nitrate and relevant function microorganisms in the landfill. Results also indicate that CH4 mitigation would have higher potential by increasing electron acceptor contents and promoting the growth of relevant function microorganisms.

  18. The Relation between Diverse Phenotypes of PCOS with Clinical Manifestations, Anthropometric Indices and Metabolic Characteristics.

    Science.gov (United States)

    Shahrami, Seyedeh Hajar; Abbasi Ranjbar, Zahra; Milani, Forozan; Kezem-Nejad, Ehsan; Hassanzadeh Rad, Afagh; Dalil Heirat, Seyedeh Fatemeh

    2016-02-01

    Critical issue regarding to variation of findings based on different phenotypes led investigators to define whether they are distinct features or overlapping ones. Therefore, we aimed to investigate the association between diverse phenotypes of PCOS (Poly Cystic Ovary Syndrome) with clinical manifestations, anthropometric indices, and metabolic characteristics. This was a descriptive cross-sectional study conducted in 15-39 years old women with PCOS referred to infertility clinics in the north part of Iran, Rasht during 2010-2011. Data were gathered through an interview by a form consisted of demographic characteristics, laboratory findings, ovarian volume and anthropometric indices. A total of 214 patients consisted of 161 PCOS (cases) and 53 normal women (controls) participated in this study. The most prevalent phenotype in PCOS population was IM/PCO/HA (54%), followed by IM/HA (28%) and IM/PCO (13%). PCO/HA was present only in 6 PCOS patients (5%). PCOS patients were significantly younger than controls (P=0.07). Results showed that increased ovarian volume were higher in PCOS group in comparison with controls and IM/PCO/HA, and IM/PCO had respectively the largest ovarian volumes. Also, a significant relation was observed based on Cholesterol, 17OHP, LH, TG, 2hpp, and LH/FSH between patients with PCOS and control groups. There were significant differences in demographic, anthropometric, hormonal and ultrasound findings between PCOS and controls. Therefore, it seems that classification of the characteristics of each phenotype could offer an appropriate guide for screening risks of PCOS and may facilitate performing most favorable treatment for these complications.

  19. Physiologically anaerobic microorganisms of the deep subsurface

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, S.E. Jr.; Chung, K.T.

    1991-06-01

    This study seeks to determine numbers, diversity, and morphology of anaerobic microorganisms in 15 samples of subsurface material from the Idaho National Engineering Laboratory, in 18 samples from the Hanford Reservation and in 1 rock sample from the Nevada Test Site; set up long term experiments on the chemical activities of anaerobic microorganisms based on these same samples; work to improve methods for the micro-scale determination of in situ anaerobic microbial activity;and to begin to isolate anaerobes from these samples into axenic culture with identification of the axenic isolates.

  20. Intraspecific variation in aerobic and anaerobic locomotion

    DEFF Research Database (Denmark)

    Svendsen, Jon Christian; Tirsgård, Bjørn; Cordero, Gerardo A.

    2015-01-01

    to unsteady (i.e., burst-assisted) swimming is associated with anaerobic metabolism evidenced as excess post exercise oxygen consumption (EPOC); (2) variation in swimming performance (critical swimming speed; U crit) correlates with metabolic scope (MS) or anaerobic capacity (i.e., maximum EPOC); (3...... respirometry and video analysis. Results showed that anaerobic swimming costs (i.e., EPOC) increase linearly with the number of bursts in S. aurata, with each burst corresponding to 0.53 mg O2 kg(-1). Data are consistent with a previous study on striped surfperch (Embiotoca lateralis), a labriform swimmer...

  1. Bacterial communities associated with Shinkaia crosnieri from the Iheya North, Okinawa Trough: Microbial diversity and metabolic potentials

    Science.gov (United States)

    Zhang, Jian; Zeng, Zhi-gang; Chen, Shuai; Sun, Li

    2018-04-01

    Shinkaia crosnieri is a galatheid crab endemic to the deep-sea hydrothermal systems in the Okinawa Trough. In this study, we systematically analyzed and compared the diversity and metabolic potentials of the microbial communities in different tissues (setae, gill, and intestine) of S. crosnieri by high-throughput sequencing technology and quantitative real-time polymerase chain reaction. Sequence analysis based on the V3-V4 regions of the 16S rRNA gene obtained 408,079 taxon tags, which covered 15 phyla, 22 classes, 32 orders, 42 families, and 25 genera. Overall, the microbial communities in all tissues were dominated by Epsilonproteobacteria and Gammaproteobacteria, of which Epsilonproteobacteria was the largest class and accounted for 85.24% of the taxon tags. In addition, 20 classes of bacteria were discovered for the first time to be associated with S. crosnieri and no archaea were detected. Comparative analysis showed that (i) bacteria from different tissues fell into different groups by β-diversity analysis, (ii) bacterial communities in intestine were similar to that in gill and much more diverse than that in setae, and the sulfur-oxidizing genus Sulfurovum was markedly enriched in intestine and gill. Furthermore, bacteria potentially involved in methane, nitrogen, and metal metabolisms were detected in all samples. The key genes of aprA/dsrA and pmoA involved in sulfate reducing and methane oxidization, respectively, were detected in the gill and gut communities for the first time, and pmoA was significantly more abundant in gill and setae than in intestine. These results provide the first comparative and relatively complete picture of the diversity and metabolic potentials of the bacteria in different tissues of S. crosnieri. These results also indicate that the composition of the microbial communities in hydrothermal fauna changes with time, suggesting the importance of environmental influence.

  2. ‘Candidatus Competibacter’-lineage genomes retrieved from metagenomes reveal functional metabolic diversity

    DEFF Research Database (Denmark)

    McIlroy, Simon Jon; Albertsen, Mads; Andresen, Eva Kammer

    2014-01-01

    as for denitrification, nitrogen fixation, fermentation, trehalose synthesis and utilisation of glucose and lactate. Genetic comparison of P metabolism pathways with sequenced PAOs revealed the absence of the Pit phosphate transporter in the Competibacter-lineage genomes—identifying a key metabolic difference...

  3. Rewiring carbohydrate catabolism differentially affects survival of pancreatic cancer cell lines with diverse metabolic profiles

    Science.gov (United States)

    Tataranni, Tiziana; Agriesti, Francesca; Ruggieri, Vitalba; Mazzoccoli, Carmela; Simeon, Vittorio; Laurenzana, Ilaria; Scrima, Rosella; Pazienza, Valerio; Capitanio, Nazzareno; Piccoli, Claudia

    2017-01-01

    An increasing body of evidence suggests that targeting cellular metabolism represents a promising effective approach to treat pancreatic cancer, overcome chemoresistance and ameliorate patient's prognosis and survival. In this study, following whole-genome expression analysis, we selected two pancreatic cancer cell lines, PANC-1 and BXPC-3, hallmarked by distinct metabolic profiles with specific concern to carbohydrate metabolism. Functional comparative analysis showed that BXPC-3 displayed a marked deficit of the mitochondrial respiratory and oxidative phosphorylation activity and a higher production of reactive oxygen species and a reduced NAD+/NADH ratio, indicating their bioenergetic reliance on glycolysis and a different redox homeostasis as compared to PANC-1. Both cell lines were challenged to rewire their metabolism by substituting glucose with galactose as carbon source, a condition inhibiting the glycolytic flux and fostering full oxidation of the sugar carbons. The obtained data strikingly show that the mitochondrial respiration-impaired-BXPC-3 cell line was unable to sustain the metabolic adaptation required by glucose deprivation/substitution, thereby resulting in a G2\\M cell cycle shift, unbalance of the redox homeostasis, apoptosis induction. Conversely, the mitochondrial respiration-competent-PANC-1 cell line did not show clear evidence of cell sufferance. Our findings provide a strong rationale to candidate metabolism as a promising target for cancer therapy. Defining the metabolic features at time of pancreatic cancer diagnosis and likely of other tumors, appears to be crucial to predict the responsiveness to therapeutic approaches or coadjuvant interventions affecting metabolism. PMID:28476035

  4. Metabolism

    Science.gov (United States)

    ... Are More Common in People With Type 1 Diabetes Metabolic Syndrome Your Child's Weight Healthy Eating Endocrine System Blood Test: Basic Metabolic Panel (BMP) Activity: Endocrine System Growth Disorders Diabetes Center Thyroid Disorders Your Endocrine System Movie: Endocrine ...

  5. Metagenomic approach reveals microbial diversity and predictive microbial metabolic pathways in Yucha, a traditional Li fermented food.

    Science.gov (United States)

    Zhang, Jiachao; Wang, Xiaoru; Huo, Dongxue; Li, Wu; Hu, Qisong; Xu, Chuanbiao; Liu, Sixin; Li, Congfa

    2016-08-31

    Yucha is a typical traditional fermented food of the Li population in the Hainan province of China, and it is made up of cooked rice and fresh fish. In the present study, metagenomic approach and culture-dependent technology were applied to describe the diversity of microbiota and identify beneficial microbes in the Yucha. At the genus level, Lactobacillus was the most abundant genus (43.82% of the total reads), followed by Lactococcus, Enterococcus, Vibrio, Weissella, Pediococcus, Enterobacter, Salinivibrio, Acinetobacter, Macrococcus, Kluyvera and Clostridium; this result was confirmed by q-PCR. PCoA based on Weighted UniFrac distances showed an apparent clustering pattern for Yucha samples from different locations, and Lactobacillus sakei, Lactobacillus saniviri and Staphylococcus sciuri represented OTUs according to the major identified markers. At the microbial functional level, it was observed that there was an enrichment of metabolic functional features, including amino acid and carbohydrate metabolism, which implied that the microbial metabolism in the Yucha samples tended to be vigorous. Accordingly, we further investigated the correlation between the predominant microbes and metabolic functional features. Thirteen species of Lactobacillus (147 strains) were isolated, and Lactobacillus plantarum (60 isolates) and Lactobacillus pentosus (34 isolates) were isolated from every sample.

  6. INFLUENCE OF METRONIDAZOLE, CO, CO2, AND METHANOGENS ON THE FERMENTATIVE METABOLISM OF THE ANAEROBIC FUNGUS NEOCALLIMASTIX SP STRAIN L2

    NARCIS (Netherlands)

    MARVINSIKKEMA, FD; REES, E; KRAAK, MN; GOTTSCHAL, JC; PRINS, RA

    The effects of metronidazole, CO, methanogens, and CO, on the fermentation of glucose by the anaerobic fungus Neocallimastix sp. strain L2 were investigated. Both metronidazole and CO caused a shift in the fermentation products from predominantly H-2, acetate, and formate to lactate as the major

  7. 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...

  8. Automatic process control in anaerobic digestion technology: A critical review.

    Science.gov (United States)

    Nguyen, Duc; Gadhamshetty, Venkataramana; Nitayavardhana, Saoharit; Khanal, Samir Kumar

    2015-10-01

    Anaerobic digestion (AD) is a mature technology that relies upon a synergistic effort of a diverse group of microbial communities for metabolizing diverse organic substrates. However, AD is highly sensitive to process disturbances, and thus it is advantageous to use online monitoring and process control techniques to efficiently operate AD process. A range of electrochemical, chromatographic and spectroscopic devices can be deployed for on-line monitoring and control of the AD process. While complexity of the control strategy ranges from a feedback control to advanced control systems, there are some debates on implementation of advanced instrumentations or advanced control strategies. Centralized AD plants could be the answer for the applications of progressive automatic control field. This article provides a critical overview of the available automatic control technologies that can be implemented in AD processes at different scales. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Metabolism

    Science.gov (United States)

    ... lin), which signals cells to increase their anabolic activities. Metabolism is a complicated chemical process, so it's not ... how those enzymes or hormones work. When the metabolism of body chemicals is ... Hyperthyroidism (pronounced: hi-per-THIGH-roy-dih-zum). Hyperthyroidism ...

  10. Anaerobic digestion of thermal pre-treated emulsified slaughterhouse wastes (TESW): Effect of trace element limitation on process efficiency and sludge metabolic properties.

    Science.gov (United States)

    Eftaxias, Alexandros; Diamantis, Vasileios; Aivasidis, Alexandros

    2018-06-01

    Slaughterhouse solid wastes, characterized by a high lipid content, are considered a valuable resource for energy production by means of anaerobic digestion technologies. Aim of this study was to examine the effect of trace element limitation on the mesophilic anaerobic digestion of thermally pre-treated emulsified slaughterhouse wastes (TESW). Under two distinct experimental periods (Period I - low and Period II - high trace element dosage respectively) a CSTR with sludge recirculation was operated at increasing organic loading rate (OLR) from 1.5 to 10 g L -1  d -1 . Under optimum conditions, COD removal was higher than 96%, biogas yield equal to 0.53 L g -1  COD feed and the biogas methane content 77%. Trace element limitation however, resulted in a dramatic decline in process efficiency, with VFA accumulation and events of extreme sludge flotation, despite that the soluble concentration of Ni, Co and Mo were between 12 and 28 μg L -1 . This is indicative of mass transfer limitations caused by lipids adsorption onto the anaerobic biomass. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Metagenomic Analysis of Subtidal Sediments from Polar and Subpolar Coastal Environments Highlights the Relevance of Anaerobic Hydrocarbon Degradation Processes

    Energy Technology Data Exchange (ETDEWEB)

    Espinola, Fernando J.; Dionisi, Hebe M.; Borglin, Sharon; Brislawn, Colin J.; Jansson, Janet K.; Mac Cormack, Walter P.; Carroll, Jolynn; Sjoling, Sara; Lozada , Mariana

    2018-01-02

    In this work, we analyzed the community structure and metabolic potential of sediment microbial communities in high-latitude coastal environments subjected to low to moderate levels of chronic pollution. Subtidal sediments from four low-energy inlets located in polar and subpolar regions from both Hemispheres were analyzed using large-scale 16S rRNA gene and metagenomic sequencing. Communities showed high diversity (Shannon’s index 6.8 to 10.2), with distinct phylogenetic structures (<40% shared taxa at the Phylum level among regions) but similar metabolic potential in terms of sequences assigned to KOs. Environmental factors (mainly salinity, temperature, and in less extent organic pollution) were drivers of both phylogenetic and functional traits. Bacterial taxa correlating with hydrocarbon pollution included families of anaerobic or facultative anaerobic lifestyle, such as Desulfuromonadaceae, Geobacteraceae, and Rhodocyclaceae. In accordance, biomarker genes for anaerobic hydrocarbon degradation (bamA, ebdA, bcrA, and bssA) were prevalent, only outnumbered by alkB, and their sequences were taxonomically binned to the same bacterial groups. BssA-assigned metagenomic sequences showed an extremely wide diversity distributed all along the phylogeny known for this gene, including bssA sensu stricto, nmsA, assA, and other clusters from poorly or not yet described variants. This work increases our understanding of microbial community patterns in cold coastal sediments, and highlights the relevance of anaerobic hydrocarbon degradation processes in subtidal environments.

  12. Genetic and metabolic diversity of pink-pigmented facultative methylotrophs in phyllosphere of tropical plants

    OpenAIRE

    Balachandar, D.; Raja, P.; Sundaram, SP.

    2008-01-01

    Diversity of Pink-Pigmented Facultative Methylotrophs (PPFMs) in phyllosphere of cotton, maize and sunflower was determined based on differential carbon-substrate utilization profile and Random Amplified Polymorphic DNA data. Results indicate that six diversified groups of PPFMs are found in these crops. Sunflower and maize phyllosphere harbor four different groups of methylobacteria while cotton has only two groups.

  13. Genetic and metabolic diversity of pink-pigmented facultative methylotrophs in phyllosphere of tropical plants.

    Science.gov (United States)

    Balachandar, D; Raja, P; Sundaram, Sp

    2008-01-01

    Diversity of Pink-Pigmented Facultative Methylotrophs (PPFMs) in phyllosphere of cotton, maize and sunflower was determined based on differential carbon-substrate utilization profile and Random Amplified Polymorphic DNA data. Results indicate that six diversified groups of PPFMs are found in these crops. Sunflower and maize phyllosphere harbor four different groups of methylobacteria while cotton has only two groups.

  14. 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

  15. Anaerobic fungal populations

    International Nuclear Information System (INIS)

    Brookman, J.L.; Nicholson, M.J.

    2005-01-01

    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

  16. Arsenic and selenium in microbial metabolism

    Science.gov (United States)

    Stolz, John F.; Basu, Partha; Santini, Joanne M.; Oremland, Ronald S.

    2006-01-01

    Arsenic and selenium are readily metabolized by prokaryotes, participating in a full range of metabolic functions including assimilation, methylation, detoxification, and anaerobic respiration. Arsenic speciation and mobility is affected by microbes through oxidation/reduction reactions as part of resistance and respiratory processes. A robust arsenic cycle has been demonstrated in diverse environments. Respiratory arsenate reductases, arsenic methyltransferases, and new components in arsenic resistance have been recently described. The requirement for selenium stems primarily from its incorporation into selenocysteine and its function in selenoenzymes. Selenium oxyanions can serve as an electron acceptor in anaerobic respiration, forming distinct nanoparticles of elemental selenium that may be enriched in (76)Se. The biogenesis of selenoproteins has been elucidated, and selenium methyltransferases and a respiratory selenate reductase have also been described. This review highlights recent advances in ecology, biochemistry, and molecular biology and provides a prelude to the impact of genomics studies.

  17. Altitudinal patterns of diversity and functional traits of metabolically active microorganisms in stream biofilms

    Science.gov (United States)

    Wilhelm, Linda; Besemer, Katharina; Fragner, Lena; Peter, Hannes; Weckwerth, Wolfram; Battin, Tom J

    2015-01-01

    Resources structure ecological communities and potentially link biodiversity to energy flow. It is commonly believed that functional traits (generalists versus specialists) involved in the exploitation of resources depend on resource availability and environmental fluctuations. The longitudinal nature of stream ecosystems provides changing resources to stream biota with yet unknown effects on microbial functional traits and community structure. We investigated the impact of autochthonous (algal extract) and allochthonous (spruce extract) resources, as they change along alpine streams from above to below the treeline, on microbial diversity, community composition and functions of benthic biofilms. Combining bromodeoxyuridine labelling and 454 pyrosequencing, we showed that diversity was lower upstream than downstream of the treeline and that community composition changed along the altitudinal gradient. We also found that, especially for allochthonous resources, specialisation by biofilm bacteria increased along that same gradient. Our results suggest that in streams below the treeline biofilm diversity, specialisation and functioning are associated with increasing niche differentiation as potentially modulated by divers allochthonous and autochthonous constituents contributing to resources. These findings expand our current understanding on biofilm structure and function in alpine streams. PMID:25978543

  18. An anaerobic bioreactor system for biobutanol production

    Energy Technology Data Exchange (ETDEWEB)

    Paekkilae, J.; Hillukkala, T.; Myllykoski, L.; Keiski, R.L. (Univ. of Oulu, Dept. of Process and Environmental Engineering (Finland)). email: johanna.pakkila@oulu.fi

    2009-07-01

    Concerns about the greenhouse effect, as well as legislation to reduce CO{sub 2} emissions and to increase the use of renewable energy have been the main reasons for the increased production and use of biofuels. In addition to bioethanol and biodiesel production, the research on biobutanol production has also increased during the past years. Butanol can be produced by chemical or biochemical routes. Fuel properties of butanol are considered to be superior to ethanol because of higher energy content, and better air-to-fuel ratio. Butanol is also less volatile and explosive than ethanol, has higher flash point and lower vapour pressure which makes it safer to handle. Biobutanol production is an anaerobic two-stage fermentation process where acetic and butyric acids, carbon dioxide and hydrogen are first produced in the acidogenic phase. Then the culture undergoes metabolic shift to solventogenic phase and acids are converted into acetone, ethanol and butanol. At the end of the fermentation, products are recovered from the cell mass, other suspended solids, and by-products. Several species of Clostridium bacteria are capable to metabolize different sugars, amino and organic acids, polyalcohols and other organic compounds to butanol and other solvents. Feedstock materials for biobutanol are diverse, including different kind of by-products, wastes and residues of agriculture and industry. Optimal fermentation conditions (pH, temperature, nutrients), products and their ratio vary with strains and substrates used. Biobutanol production has still some limitations including butanol toxicity to culture leading to low butanol yields. The product inhibition hinders the yield of butanol and acids, making integrated product separation process highly favorable. Butanol recovery from fermentation broth is expensive because of the low butanol concentration and high boiling point (118 degC). Several different recovery methods are available. Membrane-based methods such as membrane

  19. Novel Insights into the Diversity of Catabolic Metabolism from Ten Haloarchaeal Genomes

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iain; Scheuner, Carmen; Goker, Markus; Mavromatis, Kostas; Hooper, Sean D.; Porat, Iris; Klenk, Hans-Peter; Ivanova, Natalia; Kyrpides, Nikos

    2011-05-03

    The extremely halophilic archaea are present worldwide in saline environments and have important biotechnological applications. Ten complete genomes of haloarchaea are now available, providing an opportunity for comparative analysis. We report here the comparative analysis of five newly sequenced haloarchaeal genomes with five previously published ones. Whole genome trees based on protein sequences provide strong support for deep relationships between the ten organisms. Using a soft clustering approach, we identified 887 protein clusters present in all halophiles. Of these core clusters, 112 are not found in any other archaea and therefore constitute the haloarchaeal signature. Four of the halophiles were isolated from water, and four were isolated from soil or sediment. Although there are few habitat-specific clusters, the soil/sediment halophiles tend to have greater capacity for polysaccharide degradation, siderophore synthesis, and cell wall modification. Halorhabdus utahensis and Haloterrigena turkmenica encode over forty glycosyl hydrolases each, and may be capable of breaking down naturally occurring complex carbohydrates. H. utahensis is specialized for growth on carbohydrates and has few amino acid degradation pathways. It uses the non-oxidative pentose phosphate pathway instead of the oxidative pathway, giving it more flexibility in the metabolism of pentoses. These new genomes expand our understanding of haloarchaeal catabolic pathways, providing a basis for further experimental analysis, especially with regard to carbohydrate metabolism. Halophilic glycosyl hydrolases for use in biofuel production are more likely to be found in halophiles isolated from soil or sediment.

  20. Phenotypic properties and microbial diversity of methanogenic granules from a full-scale upflow anaerobic sludge bed reactor treating brewery wastewater.

    Science.gov (United States)

    Díaz, Emiliano E; Stams, Alfons J M; Amils, Ricardo; Sanz, José L

    2006-07-01

    Methanogenic granules from an anaerobic bioreactor that treated wastewater of a beer brewery consisted of different morphological types of granules. In this study, the microbial compositions of the different granules were analyzed by molecular microbiological techniques: cloning, denaturing gradient gel electrophoresis and fluorescent in situ hybridization (FISH), and scanning and transmission electron microscopy. We propose here that the different types of granules reflect the different stages in the life cycle of granules. Young granules were small, black, and compact and harbored active cells. Gray granules were the most abundant granules. These granules have a multilayer structure with channels and void areas. The core was composed of dead or starving cells with low activity. The brown granules, which were the largest granules, showed a loose and amorphous structure with big channels that resulted in fractured zones and corresponded to the older granules. Firmicutes (as determined by FISH) and Nitrospira and Deferribacteres (as determined by cloning and sequencing) were the predominant Bacteria. Remarkably, Firmicutes could not be detected in the brown granules. The methanogenic Archaea identified were Methanosaeta concilii (70 to 90% by FISH and cloning), Methanosarcina mazei, and Methanospirillum spp. The phenotypic appearance of the granules reflected the physiological condition of the granules. This may be valuable to easily select appropriate seed sludges to start up other reactors.

  1. Impact of Trichloroethylene Exposure on the Microbial Diversity and Protein Expression in Anaerobic Granular Biomass at 37°C and 15°C

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    Alma Siggins

    2012-01-01

    Full Text Available Granular biomass from a laboratory-scale anaerobic bioreactor trial was analysed to identify changes in microbial community structure and function in response to temperature and trichloroethylene (TCE. Two bioreactors were operated at 37°C, while two were operated at 15°C. At the time of sampling, one of each temperature pair of bioreactors was exposed to process failure-inducing concentrations of TCE (60 mg L−1 while the other served as a TCE-free control. Bacterial community structure was investigated using denaturing gradient gel electrophoresis (DGGE and 16S rRNA gene clone library analysis. Temperature was identified as an important factor for bacterial community composition, while minor differences were associated with trichloroethylene supplementation. Proteobacteria was the dominant phylum in all bioreactors, while clone library analysis revealed a higher proportion of Bacteroidetes-, Chloroflexi-, and Firmicutes-like clones at 15°C than at 37°C. Comparative metaproteomics in the presence and absence of TCE was carried out by two-dimensional gel electrophoresis (2-DGE, and 28 protein spots were identified, with putative functions related to cellular processes, including methanogenesis, glycolysis, the glyoxylate cycle, and the methyl malonyl pathway. A good agreement between metaproteomic species assignment and phylogenetic information was observed, with 10 of the identified proteins associated with members of the phylum Proteobacteria.

  2. Metagenomic and Metatranscriptomic Analyses of Diverse Watermelon Cultivars Reveal the Role of Fruit Associated Microbiome in Carbohydrate Metabolism and Ripening of Mature Fruits

    Directory of Open Access Journals (Sweden)

    Thangasamy Saminathan

    2018-01-01

    Full Text Available The plant microbiome is a key determinant of plant health and productivity, and changes in the plant microbiome can alter the tolerance to biotic and abiotic stresses and the quality of end produce. Little is known about the microbial diversity and its effect on carbohydrate metabolism in ripe fruits. In this study, we aimed to understand the diversity and function of microorganisms in relation to carbohydrate metabolism of ripe watermelon fruits. We used 16S metagenomics and RNAseq metatranscriptomics for analysis of red (PI459074, Congo, and SDRose and yellow fruit-flesh cultivars (PI227202, PI435990, and JBush of geographically and metabolically diverse watermelon cultivars. Metagenomics data showed that Proteobacteria were abundant in SDRose and PI227202, whereas Cyanobacteria were most abundant in Congo and PI4559074. In the case of metatranscriptome data, Proteobacteria was the most abundant in all cultivars. High expression of genes linked to infectious diseases and the expression of peptidoglycan hydrolases associated to pathogenicity of eukaryotic hosts was observed in SDRose, which could have resulted in low microbial diversity in this cultivar. The presence of GH28, associated with polygalacturonase activity in JBush and SDRose could be related to cell wall modifications including de-esterification and depolymerization, and consequent loss of galacturonic acid and neutral sugars. Moreover, based on the KEGG annotation of the expressed genes, nine α-galactosidase genes involved in key processes of galactosyl oligosaccharide metabolism, such as raffinose family were identified and galactose metabolism pathway was reconstructed. Results of this study underline the links between the host and fruit-associated microbiome in carbohydrate metabolism of the ripe fruits. The cultivar difference in watermelon reflects the quantum and diversity of the microbiome, which would benefit watermelon and other plant breeders aiming at the holobiont

  3. Arsenic, Anaerobes, and Autotrophy.

    Science.gov (United States)

    Oremland, R. S.

    2008-12-01

    That microbes have resistance to the toxic arsenic oxyanions arsenite [As(III)] and arsenate [As(V)] has been recognized for some time. More recently it was shown that certain prokaryotes can demonstrate As- dependent growth by conserving the energy gained from the aerobic oxidation of As(III) to As(V), or from the reduction of As(V) to As(III) under anaerobic conditions. During the course of our field studies of two alkaline, hypersaline soda lakes (Mono Lake and Searles Lake, CA) we have discovered several new anaerobic chemo- and photo-autotrophic bacteria that can center their energy gain around the redox reactions between As(III) and As(V). Alkalilimnicola ehrlichii, isolated from the water column of Mono Lake is a nitrate-respiring, As(III)-oxidizing chemoautotroph of the gamma-proteobacteria that has a highly flexible metabolism. It can function either as a facultative anaerobe or as a chemo-autotroph, or as a heterotroph (Hoeft et al., 2007). In contrast, strain MLMS-1 of the delta-proteobacteria was also isolated from Mono Lake, but to date is the first example of an obligate As(V)-respirer that is also an obligate chemo-autotroph, gaining its energy via the oxidation of sulfide to sulfate (Hoeft et al., 2004). Strain SLAS-1, isolated from salt-saturated Searles Lake is a member of the Halananerobiales, and can either grow as a heterotroph (lactate e-donor) or chemo- autotroph (sulfide e-donor) while respiring As(V). The fact that it can achieve this feat at salt-saturation (~ 340 g/L) makes it a true extremophile (Oremland et. al., 2005). Finally, strain PHS-1 isolated from a hot spring on Paoha island in Mono Lake is the first example of a photosynthetic bacterium of the gamma- proteobacteria able to link its growth to As(III)-dependent anoxygenic photosynthesis (Kulp et al., 2008). These novel microbes give us new insights into the evolution of arsenic-based metabolism and their role in the biogeochemical cycling of this toxic element. Hoeft, S.E., et

  4. Long-term high-solids anaerobic digestion of food waste: Effects of ammonia on process performance and microbial community.

    Science.gov (United States)

    Peng, Xuya; Zhang, ShangYi; Li, Lei; Zhao, Xiaofei; Ma, Yao; Shi, Dezhi

    2018-04-22

    A long-term high solids anaerobic digestion of food waste was conducted to identify microbial mechanisms of ammonia inhibition during digestion and to clarify correlations between ammonia accumulation, microbial community dynamics (diversity, composition, and interactions), and process stability. Results show that the effects of ammonia on process performance and microbial community were indirectly caused by volatile fatty acid accumulation. Excess free ammonia blocked acetate metabolism, leading to process instability. Accumulated acetate caused feedback inhibition at the acetogenesis stage, which resulted in considerable accumulation of propionate, valerate, and other long-chain fatty acids. This high concentration of volatile fatty acids reduced the abundance of syntrophic acetogenic bacteria and allowed hydrolytic fermentative bacteria to dominate. The normally interactive and orderly metabolic network was broken, which further exacerbated the process instability. These results improve the understanding of microbial mechanisms which contribute to process instability and provide guidance for the microbial management of anaerobic digesters. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Effect of Condensed Tannins on Bacterial Diversity and Metabolic Activity in the Rat Gastrointestinal Tract

    Science.gov (United States)

    Smith, Alexandra H.; Mackie, Roderick I.

    2004-01-01

    The effect of dietary condensed tannins (proanthocyanidins) on rat fecal bacterial populations was ascertained in order to determine whether the proportion on tannin-resistant bacteria increased and if there was a change in the predominant bacterial populations. After 3 weeks of tannin diets the proportion of tannin-resistant bacteria increased significantly (P tannin diet and to 47.2% ± 5.1% with a 2% tannin diet. The proportion of tannin-resistant bacteria returned to preexposure levels in the absence of dietary tannins. A shift in bacterial populations was confirmed by molecular fingerprinting of fecal bacterial populations by denaturing gradient gel electrophoresis (DGGE). Posttreatment samples were generally still distinguishable from controls after 3.5 weeks. Sequence analysis of DGGE bands and characterization of tannin-resistant isolates indicated that tannins selected for Enterobacteriaceae and Bacteroides species. Dot blot quantification confirmed that these gram-negative bacterial groups predominated in the presence of dietary tannins and that there was a corresponding decrease in the gram-positive Clostridium leptum group and other groups. Metabolic fingerprint patterns revealed that functional activities of culturable fecal bacteria were affected by the presence of tannins. Condensed tannins of Acacia angustissima altered fecal bacterial populations in the rat gastrointestinal tract, resulting in a shift in the predominant bacteria towards tannin-resistant gram-negative Enterobacteriaceae and Bacteroides species. PMID:14766594

  6. Metabolic diversity and ecological niches of Achromatium populations revealed with single-cell genomic sequencing

    Directory of Open Access Journals (Sweden)

    Muammar eMansor

    2015-08-01

    Full Text Available Large, sulfur-cycling, calcite-precipitating bacteria in the genus Achromatium represent a significant proportion of bacterial communities near sediment-water interfaces throughout the world. Our understanding of their potentially crucial roles in calcium, carbon, sulfur, nitrogen, and iron cycling is limited because they have not been cultured or sequenced using environmental genomics approaches to date. We utilized single-cell genomic sequencing to obtain one incomplete and two nearly complete draft genomes for Achromatium collected at Warm Mineral Springs, FL. Based on 16S rRNA gene sequences, the three cells represent distinct and relatively distant Achromatium populations (91-92% identity. The draft genomes encode key genes involved in sulfur and hydrogen oxidation; oxygen, nitrogen and polysulfide respiration; carbon and nitrogen fixation; organic carbon assimilation and storage; chemotaxis; twitching motility; antibiotic resistance; and membrane transport. Known genes for iron and manganese energy metabolism were not detected. The presence of pyrophosphatase and vacuolar (V-type ATPases, which are generally rare in bacterial genomes, suggests a role for these enzymes in calcium transport, proton pumping, and/or energy generation in the membranes of calcite-containing inclusions.

  7. Legionella shows a diverse secondary metabolism dependent on a broad spectrum Sfp-type phosphopantetheinyl transferase

    Directory of Open Access Journals (Sweden)

    Nicholas J. Tobias

    2016-11-01

    Full Text Available Several members of the genus Legionella cause Legionnaires’ disease, a potentially debilitating form of pneumonia. Studies frequently focus on the abundant number of virulence factors present in this genus. However, what is often overlooked is the role of secondary metabolites from Legionella. Following whole genome sequencing, we assembled and annotated the Legionella parisiensis DSM 19216 genome. Together with 14 other members of the Legionella, we performed comparative genomics and analysed the secondary metabolite potential of each strain. We found that Legionella contains a huge variety of biosynthetic gene clusters (BGCs that are potentially making a significant number of novel natural products with undefined function. Surprisingly, only a single Sfp-like phosphopantetheinyl transferase is found in all Legionella strains analyzed that might be responsible for the activation of all carrier proteins in primary (fatty acid biosynthesis and secondary metabolism (polyketide and non-ribosomal peptide synthesis. Using conserved active site motifs, we predict some novel compounds that are probably involved in cell-cell communication, differing to known communication systems. We identify several gene clusters, which may represent novel signaling mechanisms and demonstrate the natural product potential of Legionella.

  8. EFFECT OF SIZE OF INTESTINAL DIVERSIONS IN OBESE PATIENTS WITH METABOLIC SYNDROME SUBMITTED TO GASTRIC BYPASS.

    Science.gov (United States)

    Ramos, Rafael Jacques; Mottin, Cláudio Corá; Alves, Letícia Biscaino; Benzano, Daniela; Padoin, Alexandre Vontobel

    There is no consensus on the ideal size of intestinal loops in gastric bypass of bariatric surgeries. To evaluate the metabolic outcome of patients submitted to gastric bypass with alimentary and biliopancreatic loops of different sizes. Was conducted a retrospective cohort study in diabetic obese patients (BMI≥35 kg/m2) with metabolic syndrome submitted to gastric bypass. The patients were divided into three groups according to the size of the intestinal loop: group 1, biliopancreatic limb 50 cm length and alimentary limb 100 cm length; group 2 , biliopancreatic limb 50 cm length and alimentary limb 150 cm length; and group 3, biliopancreatic limb 100 cm length and alimentary limb 150 cm length. The effect of gastric bypass with different sizes of intestinal loops in relation to the parameters that define metabolic syndrome was determined. Sixty-three patients were evaluated, and they had a mean age of 44.7±9.4 years. All were diabetics, with 62 (98.4%) being hypertensive and 51 (82.2%) dyslipidemic. The three groups were homogeneous in relation to the variables. In 24 months, there was a remission of systemic arterial hypertension in 65% of patients in group 1, 62.5% in group 2 and 68.4% in group 3. Remission of diabetes occurred in 85% of patients in group 1, 83% in group 2 and 84% in group 3. There was no statistical difference in %LEW between the groups, and waist measurements decreased in a homogeneous way in all groups. The size of loops also had no influence on the improvement in dyslipidemia. Variation in size of intestinal loops does not appear to influence improvement in metabolic syndrome in this group of patients. Não há consenso sobre o tamanho ideal das alças intestinais no bypass gástrico em Y-de-Roux em cirurgias bariátricas. Avaliar os desfechos metabólicos de pacientes submetidos ao bypass gástrico com alça intestinal alimentar e biliopancreática de tamanhos diferentes. Realizou-se coorte retrospectiva em pacientes obesos (IMC≥35 kg

  9. Microorganism-regulated mechanisms of temperature effects on the performance of anaerobic digestion.

    Science.gov (United States)

    Lin, Qiang; He, Guihua; Rui, Junpeng; Fang, Xiaoyu; Tao, Yong; Li, Jiabao; Li, Xiangzhen

    2016-06-03

    Temperature is an important factor determining the performance and stability of the anaerobic digestion process. However, the microorganism-regulated mechanisms of temperature effects on the performance of anaerobic digestion systems remain further elusive. To address this issue, we investigated the changes in composition, diversity and activities of microbial communities under temperature gradient from 25 to 55 °C using 16S rRNA gene amplicon sequencing approach based on genomic DNA (refer to as "16S rDNA") and total RNA (refer to as "16S rRNA"). Microbial community structure and activities changed dramatically along the temperature gradient, which corresponded to the variations in digestion performance (e.g., daily CH4 production, total biogas production and volatile fatty acids concentration). The ratios of 16S rRNA to 16S rDNA of microbial taxa, as an indicator of the potentially relative activities in situ, and whole activities of microbial community assessed by the similarity between microbial community based on 16S rDNA and rRNA, varied strongly along the temperature gradient, reflecting different metabolic activities. The daily CH4 production increased with temperature from 25 to 50 °C and declined at 55 °C. Among all the examined microbial properties, the whole activities of microbial community and alpha-diversity indices of both microbial communities and potentially relative activities showed highest correlations to the performance. The whole activities of microbial community and alpha-diversity indices of both microbial communities and potentially relative activities were sensitive indicators for the performance of anaerobic digestion systems under temperature gradient, while beta-diversity could predict functional differences. Microorganism-regulated mechanisms of temperature effects on anaerobic digestion performance were likely realized through increasing alpha-diversity of both microbial communities and potentially relative activities to supply

  10. Metabolic and functional diversity of saponins, biosynthetic intermediates and semi-synthetic derivatives

    Science.gov (United States)

    Moses, Tessa; Papadopoulou, Kalliope K.

    2014-01-01

    Saponins are widely distributed plant natural products with vast structural and functional diversity. They are typically composed of a hydrophobic aglycone, which is extensively decorated with functional groups prior to the addition of hydrophilic sugar moieties, to result in surface-active amphipathic compounds. The saponins are broadly classified as triterpenoids, steroids or steroidal glycoalkaloids, based on the aglycone structure from which they are derived. The saponins and their biosynthetic intermediates display a variety of biological activities of interest to the pharmaceutical, cosmetic and food sectors. Although their relevance in industrial applications has long been recognized, their role in plants is underexplored. Recent research on modulating native pathway flux in saponin biosynthesis has demonstrated the roles of saponins and their biosynthetic intermediates in plant growth and development. Here, we review the literature on the effects of these molecules on plant physiology, which collectively implicate them in plant primary processes. The industrial uses and potential of saponins are discussed with respect to structure and activity, highlighting the undoubted value of these molecules as therapeutics. PMID:25286183

  11. High-speed stimulated Raman scattering microscopy for studying the metabolic diversity of motile Euglena gracilis

    Science.gov (United States)

    Suzuki, Y.; Wakisaka, Y.; Iwata, O.; Nakashima, A.; Ito, T.; Hirose, M.; Domon, R.; Sugawara, M.; Tsumura, N.; Watarai, H.; Shimobaba, T.; Suzuki, K.; Goda, K.; Ozeki, Y.

    2017-02-01

    Microalgae have been receiving great attention for their ability to produce biomaterials that are applicable for food supplements, drugs, biodegradable plastics, and biofuels. Among such microalgae, Euglena gracilis has become a popular species by virtue of its capability of accumulating useful metabolites including paramylon and lipids. In order to maximize the production of desired metabolites, it is essential to find ideal culturing conditions and to develop efficient methods for genetic transformation. To achieve this, understanding and controlling cell-to-cell variations in response to external stress is essential, with chemically specific analysis of microalgal cells including E. gracilis. However, conventional analytical tools such as fluorescence microscopy and spontaneous Raman scattering are not suitable for evaluation of diverse populations of motile microalgae, being restricted either by the requirement for fluorescent labels or a limited imaging speed, respectively. Here we demonstrate video-rate label-free metabolite imaging of live E. gracilis using stimulated Raman scattering (SRS) - an optical spectroscopic method for probing the vibrational signatures of molecules with orders of magnitude higher sensitivity than spontaneous Raman scattering. Our SRS's highspeed image acquisition (27 metabolite images per second) allows for population analysis of live E. gracilis cells cultured under nitrogen-deficiency - a technique for promoting the accumulation of paramylon and lipids within the cell body. Thus, our SRS system's fast imaging capability enables quantification and analysis of previously unresolvable cell-to-cell variations in the metabolite accumulation of large motile E. gracilis cell populations.

  12. Beneficial Effects of a Dietary Weight Loss Intervention on Human Gut Microbiome Diversity and Metabolism Are Not Sustained during Weight Maintenance.

    Science.gov (United States)

    Heinsen, Femke-Anouska; Fangmann, Daniela; Müller, Nike; Schulte, Dominik M; Rühlemann, Malte C; Türk, Kathrin; Settgast, Ute; Lieb, Wolfgang; Baines, John F; Schreiber, Stefan; Franke, Andre; Laudes, Matthias

    2016-01-01

    In the present study, we examined the effect of a very low-calorie diet(VLCD)-based obesity program on human gut microbiome diversity and metabolism during weight loss and weight maintenance. Obese subjects underwent 3 months of VLCD followed by 3 months of weight maintenance. A lean and an obese control group were included. The microbiome was characterized by performing high-throughput dual-indexed 16S rDNA amplicon sequencing. At baseline, a significant difference in the Firmicutes/Bacteroidetes ratio between the lean and obese individuals was observed (p = 0.047). The VLCD resulted in significant alterations in gut microbiome diversity from baseline to 3 months (p = 0.0053). Acinetobacter represented an indicator species for the observed effect (indicator value = 0.998, p = 0.006). Metabolic analyses revealed alterations of the bacterial riboflavin pathway from baseline to 3 months (pnom = 0.0078). These changes in diversity and bacterial metabolism induced by VLCD diminished during the weight maintenance phase, despite sustained reductions in body weight and sustained improvements of insulin sensitivity. The present data show that a VLCD is able to beneficially alter both gut microbiome diversity and metabolism in obese humans, but that these changes are not sustained during weight maintenance. This finding might suggest that the microbiome should be targeted during obesity programs. © 2016 The Author(s) Published by S. Karger GmbH, Freiburg.

  13. Beneficial Effects of a Dietary Weight Loss Intervention on Human Gut Microbiome Diversity and Metabolism Are Not Sustained during Weight Maintenance

    Directory of Open Access Journals (Sweden)

    Femke-Anouska Heinsen

    2016-11-01

    Full Text Available Objective: In the present study, we examined the effect of a very low-calorie diet(VLCD-based obesity program on human gut microbiome diversity and metabolism during weight loss and weight maintenance. Methods: Obese subjects underwent 3 months of VLCD followed by 3 months of weight maintenance. A lean and an obese control group were included. The microbiome was characterized by performing high-throughput dual-indexed 16S rDNA amplicon sequencing. Results: At baseline, a significant difference in the Firmicutes/Bacteroidetes ratio between the lean and obese individuals was observed (p = 0.047. The VLCD resulted in significant alterations in gut microbiome diversity from baseline to 3 months (p = 0.0053. Acinetobacter represented an indicator species for the observed effect (indicator value = 0.998, p = 0.006. Metabolic analyses revealed alterations of the bacterial riboflavin pathway from baseline to 3 months (pnom = 0.0078. These changes in diversity and bacterial metabolism induced by VLCD diminished during the weight maintenance phase, despite sustained reductions in body weight and sustained improvements of insulin sensitivity. Conclusion: The present data show that a VLCD is able to beneficially alter both gut microbiome diversity and metabolism in obese humans, but that these changes are not sustained during weight maintenance. This finding might suggest that the microbiome should be targeted during obesity programs.

  14. Genetic and metabolic diversity in Stevia rebaudiana using RAPD and HPTLC analysis.

    Science.gov (United States)

    Chester, Karishma; Tamboli, Ennus Tajuddin; Parveen, Rabea; Ahmad, Sayeed

    2013-06-01

    Stevia rebaudiana Bertoni (Asteraceae) is an important medicinal plant and is much used due to its zero calories sweetening property. Stevia leaves as well as its extracts and pure compounds are currently used in the preparation of several medicines, food products and neutraceuticals. To study the genetic and metabolic variability in S. rebaudiana among accessions of different geographical regions of India using random amplified polymorphic DNA (RAPD) markers and high-performance thin layer chromatography (HPTLC) analysis. The RAPD analysis of Stevia rebaudiana (11 accessions) was carried out using 20 random operon primers. Dendrogram was constructed for cluster analysis based on the unweighted pair group method with arithmetic means (UPGMA) using Winboot. The HPTLC analysis of all samples was carried out on silica using acetone:ethyl acetate:water (5:4:1, v/v/v) for fingerprinting and quantification of stevioside and rebaudioside A at 360 nm after spraying with anisaldehyde sulphuric acid. Ten out of 20 primers screened were found most informative; amplification products of the genotypes yielded a total of 87 scorable bands (67 polymorphic), whereas genetic similarity (GS) coefficient (0.01-0.08) and polymorphism (67.24-92.40%) showed huge variability. Similarly, HPTLC analysis showed large variation among different samples with respect to their presence or absence of metabolite and their concentration. Out of the 11 Stevia accessions, Delhi and Mohali varieties showed much relatedness with each other and were concluded to be the superior genotype in context to RAPD and HPTLC analysis. The information obtained here could be valuable for devising strategies for cultivating this medicinal plant.

  15. Livestock Anaerobic Digester Database

    Science.gov (United States)

    The Anaerobic Digester Database provides basic information about anaerobic digesters on livestock farms in the United States, organized in Excel spreadsheets. It includes projects that are under construction, operating, or shut down.

  16. Anaerobes in pleuropulmonary infections

    Directory of Open Access Journals (Sweden)

    De A

    2002-01-01

    Full Text Available A total of 76 anaerobes and 122 aerobes were isolated from 100 patients with pleuropulmonary infections, e.g. empyema (64, pleural effusion (19 and lung abscess (13. In 14% of the patients, only anaerobes were recovered, while a mixture of aerobes and anaerobes was encountered in 58%. From all cases of lung abscess, anaerobic bacteria were isolated, alone (04 or along with aerobic bacteria (13. From empyema and pleural effusion cases, 65.6% and 68.4% anaerobes were recovered respectively. Amongst anaerobes, gram negative anaerobic bacilli predominated (Prevotella melaninogenicus 16, Fusobacterium spp. 10, Bacteroides spp. 9, followed by gram positive anaerobic cocci (Peptostreptococcus spp. 31. Coliform bacteria (45 and Pseudomonas aeruginosa (42 were the predominant aerobic isolates.

  17. Diverse and Abundant Secondary Metabolism Biosynthetic Gene Clusters in the Genomes of Marine Sponge Derived Streptomyces spp. Isolates

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    Stephen A. Jackson

    2018-02-01

    Full Text Available The genus Streptomyces produces secondary metabolic compounds that are rich in biological activity. Many of these compounds are genetically encoded by large secondary metabolism biosynthetic gene clusters (smBGCs such as polyketide synthases (PKS and non-ribosomal peptide synthetases (NRPS which are modular and can be highly repetitive. Due to the repeats, these gene clusters can be difficult to resolve using short read next generation datasets and are often quite poorly predicted using standard approaches. We have sequenced the genomes of 13 Streptomyces spp. strains isolated from shallow water and deep-sea sponges that display antimicrobial activities against a number of clinically relevant bacterial and yeast species. Draft genomes have been assembled and smBGCs have been identified using the antiSMASH (antibiotics and Secondary Metabolite Analysis Shell web platform. We have compared the smBGCs amongst strains in the search for novel sequences conferring the potential to produce novel bioactive secondary metabolites. The strains in this study recruit to four distinct clades within the genus Streptomyces. The marine strains host abundant smBGCs which encode polyketides, NRPS, siderophores, bacteriocins and lantipeptides. The deep-sea strains appear to be enriched with gene clusters encoding NRPS. Marine adaptations are evident in the sponge-derived strains which are enriched for genes involved in the biosynthesis and transport of compatible solutes and for heat-shock proteins. Streptomyces spp. from marine environments are a promising source of novel bioactive secondary metabolites as the abundance and diversity of smBGCs show high degrees of novelty. Sponge derived Streptomyces spp. isolates appear to display genomic adaptations to marine living when compared to terrestrial strains.

  18. Soil Parameters Drive the Structure, Diversity and Metabolic Potentials of the Bacterial Communities Across Temperate Beech Forest Soil Sequences.

    Science.gov (United States)

    Jeanbille, M; Buée, M; Bach, C; Cébron, A; Frey-Klett, P; Turpault, M P; Uroz, S

    2016-02-01

    Soil and climatic conditions as well as land cover and land management have been shown to strongly impact the structure and diversity of the soil bacterial communities. Here, we addressed under a same land cover the potential effect of the edaphic parameters on the soil bacterial communities, excluding potential confounding factors as climate. To do this, we characterized two natural soil sequences occurring in the Montiers experimental site. Spatially distant soil samples were collected below Fagus sylvatica tree stands to assess the effect of soil sequences on the edaphic parameters, as well as the structure and diversity of the bacterial communities. Soil analyses revealed that the two soil sequences were characterized by higher pH and calcium and magnesium contents in the lower plots. Metabolic assays based on Biolog Ecoplates highlighted higher intensity and richness in usable carbon substrates in the lower plots than in the middle and upper plots, although no significant differences occurred in the abundance of bacterial and fungal communities along the soil sequences as assessed using quantitative PCR. Pyrosequencing analysis of 16S ribosomal RNA (rRNA) gene amplicons revealed that Proteobacteria, Acidobacteria and Bacteroidetes were the most abundantly represented phyla. Acidobacteria, Proteobacteria and Chlamydiae were significantly enriched in the most acidic and nutrient-poor soils compared to the Bacteroidetes, which were significantly enriched in the soils presenting the higher pH and nutrient contents. Interestingly, aluminium, nitrogen, calcium, nutrient availability and pH appeared to be the best predictors of the bacterial community structures along the soil sequences.

  19. Anaerobic fungi

    International Nuclear Information System (INIS)

    Theodorou, M.K.; Brookman, J.; Trinci, A.P.J.

    2005-01-01

    Although the rumen represents one of the most thoroughly investigated of all microbial ecosystems, more information is required about the size, diversity and function of the various cultivatable and non-cultivatable subgroups that constitute the rumen microflora. While microbial, molecular methodologies are developing at a considerable pace, and this will ultimately assist in the description of non-cultivatable forms, there is still a need to study the cultivatable forms, and to do this we need to grow and maintain their viability in axenic laboratory culture

  20. Comparative Genomics Revealed Genetic Diversity and Species/Strain-Level Differences in Carbohydrate Metabolism of Three Probiotic Bifidobacterial Species

    Directory of Open Access Journals (Sweden)

    Toshitaka Odamaki

    2015-01-01

    Full Text Available Strains of Bifidobacterium longum, Bifidobacterium breve, and Bifidobacterium animalis are widely used as probiotics in the food industry. Although numerous studies have revealed the properties and functionality of these strains, it is uncertain whether these characteristics are species common or strain specific. To address this issue, we performed a comparative genomic analysis of 49 strains belonging to these three bifidobacterial species to describe their genetic diversity and to evaluate species-level differences. There were 166 common clusters between strains of B. breve and B. longum, whereas there were nine common clusters between strains of B. animalis and B. longum and four common clusters between strains of B. animalis and B. breve. Further analysis focused on carbohydrate metabolism revealed the existence of certain strain-dependent genes, such as those encoding enzymes for host glycan utilisation or certain membrane transporters, and many genes commonly distributed at the species level, as was previously reported in studies with limited strains. As B. longum and B. breve are human-residential bifidobacteria (HRB, whereas B. animalis is a non-HRB species, several of the differences in these species’ gene distributions might be the result of their adaptations to the nutrient environment. This information may aid both in selecting probiotic candidates and in understanding their potential function as probiotics.

  1. Anaerobic Digestion: Process

    DEFF Research Database (Denmark)

    Angelidaki, Irini; Batstone, Damien J.

    2011-01-01

    Organic waste may degrade anaerobically in nature as well as in engineered systems. The latter is called anaerobic digestion or biogasification. Anaerobic digestion produces two main outputs: An energy-rich gas called biogas and an effluent. The effluent, which may be a solid as well as liquid...... 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...

  2. The effects of micro-aeration on the phylogenetic diversity of microorganisms in a thermophilic anaerobic municipal solid-waste digester.

    Science.gov (United States)

    Tang, Yueqin; Shigematsu, Toru; Ikbal; Morimura, Shigeru; Kida, Kenji

    2004-05-01

    We demonstrated previously that micro-aeration allows construction of an effective thermophilic methane-fermentation system for treatment of municipal solid waste (MSW) without production of H(2)S. In the present study, we compared the microbial communities in a thermophilic MSW digester without aeration and with micro-aeration by fluorescence in situ hybridization (FISH), denaturing gradient gel electrophoresis (DGGE), phylogenetic analysis of libraries of 16S rRNA gene clones and quantitative real-time PCR. Moreover, we studied the activity of sulfate-reducing bacteria (SRB) by analysis of the transcription of the gene for dissimilatory sulfite reductase (dsr). Experiments using FISH revealed that microorganisms belonging to the domain Bacteria dominated in the digester both without aeration and with micro-aeration. Phylogenetic analysis based on 16S rRNA gene and analysis of bacteria by DGGE did not reveal any obvious difference within the microbial communities under the two aeration conditions, and bacteria affiliated with the phylum Firmicutes were dominant. In Archaea, the population of Methanosarcina decreased while the population of Methanoculleus increased as a result of micro-aerations as revealed by the analysis of 16S rRNA gene clones and quantitative real-time PCR. Reverse transcription and PCR (RT-PCR) demonstrated the transcription of dsrA not only in the absence of aeration but also in the presence of micro-aeration, even under conditions where no H(2)S was detected in the biogas. In conclusion, micro-aeration has no obvious effects on the phylogenetic diversity of microorganisms. Furthermore, the activity of SRBs in the digester was not repressed even though the concentration of H(2)S in the biogas was very low under the micro-aeration conditions.

  3. Anaerobic treatment techniques

    International Nuclear Information System (INIS)

    Boehnke, B.; Bischofsberger, W.; Seyfried, C.F.

    1993-01-01

    This practical and theoretical guide presents the current state of knowledge in anaerobic treatment of industrial effluents with a high organic pollutant load and sewage sludges resulting from the treatment of municipal and industrial waste water. Starting from the microbiological bases of anaerobic degradation processes including a description and critical evaluation of executed plants, the book evolves the process-technical bases of anaerobic treatment techniques, derives relative applications, and discusses these with reference to excuted examples. (orig./UWA). 232 figs [de

  4. The effects of chronic cadmium exposure on repeat swimming performance and anaerobic metabolism in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis)

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, Jessie L.; McGeer, James C., E-mail: jmcgeer@wlu.ca

    2016-04-15

    Highlights: • Exposure to 18 nM waterborne Cd induced plasma Ca loss that recovered by day 30 for lake whitefish but not brown trout. • Ucrit measured after an initial swim to 85% of Ucrit and a 30 min rest period was reduced in 18 nM Cd exposed fish compared to controls. • Swimming to 85% of Ucrit resulted in decreased muscle glycogen and increased lactate that was not recovered in the 30 min recovery period. • Second swim impairment is not related to metabolic processes in white muscle. - Abstract: This study investigates the effect of chronic Cd exposure on the ability to perform repeat swim challenges in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis). Fish were exposed to waterborne Cd (18 nM) in moderately hard water (120 mg L{sup −1} CaCO{sub 3}) for 30 days. This level of exposure has been shown to cause sublethal physiological disruption and acclimation responses but no impairment of sustained swimming capacity (U{sub crit}) in single swim challenges. Swim trials were done over the course of the exposure and each one consisted of an initial swim to 85% of the U{sub crit} of control fish, a 30 min recovery period and finally a second swim challenge to determine U{sub crit}. Plasma and tissue samples were collected before and after each of the swim periods. As expected from previous studies, Cd exposure resulted in significant accumulation of Cd in gills, liver and kidney but not in white muscle. Exposure also induced a loss of plasma Ca followed by subsequent recovery (in lake whitefish but not brown trout) with few mortalities (100% survival for lake whitefish and 93% for brown trout). Both control and exposed fish swam to 85% of the single swim U{sub crit} and no differences in performance were seen. The Ucrit of unexposed controls in the second swim challenges were not different from the single swim Ucrit. However, second swim performance was significantly reduced in Cd exposed fish, particularly after a week of exposure

  5. The effects of chronic cadmium exposure on repeat swimming performance and anaerobic metabolism in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis)

    International Nuclear Information System (INIS)

    Cunningham, Jessie L.; McGeer, James C.

    2016-01-01

    Highlights: • Exposure to 18 nM waterborne Cd induced plasma Ca loss that recovered by day 30 for lake whitefish but not brown trout. • Ucrit measured after an initial swim to 85% of Ucrit and a 30 min rest period was reduced in 18 nM Cd exposed fish compared to controls. • Swimming to 85% of Ucrit resulted in decreased muscle glycogen and increased lactate that was not recovered in the 30 min recovery period. • Second swim impairment is not related to metabolic processes in white muscle. - Abstract: This study investigates the effect of chronic Cd exposure on the ability to perform repeat swim challenges in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis). Fish were exposed to waterborne Cd (18 nM) in moderately hard water (120 mg L"−"1 CaCO_3) for 30 days. This level of exposure has been shown to cause sublethal physiological disruption and acclimation responses but no impairment of sustained swimming capacity (U_c_r_i_t) in single swim challenges. Swim trials were done over the course of the exposure and each one consisted of an initial swim to 85% of the U_c_r_i_t of control fish, a 30 min recovery period and finally a second swim challenge to determine U_c_r_i_t. Plasma and tissue samples were collected before and after each of the swim periods. As expected from previous studies, Cd exposure resulted in significant accumulation of Cd in gills, liver and kidney but not in white muscle. Exposure also induced a loss of plasma Ca followed by subsequent recovery (in lake whitefish but not brown trout) with few mortalities (100% survival for lake whitefish and 93% for brown trout). Both control and exposed fish swam to 85% of the single swim U_c_r_i_t and no differences in performance were seen. The Ucrit of unexposed controls in the second swim challenges were not different from the single swim Ucrit. However, second swim performance was significantly reduced in Cd exposed fish, particularly after a week of exposure where 31% and 38

  6. Similar PAH fate in anaerobic digesters inoculated with three microbial communities accumulating either volatile fatty acids or methane.

    Directory of Open Access Journals (Sweden)

    Florence Braun

    Full Text Available Urban sludge produced on wastewater treatment plants are often contaminated by organic pollutants such as polycyclic aromatic hydrocarbons (PAH. Their removal under methanogenic conditions was already reported, but the factors influencing this removal remain unclear. Here, we determined the influence of microbial communities on PAH removal under controlled physico-chemical conditions. Twelve mesophilic anaerobic digesters were inoculated with three microbial communities extracted from ecosystems with contrasting pollution histories: a PAH contaminated soil, a PCB contaminated sediment and a low contaminated anaerobic sludge. These anaerobic digesters were operated during 100 days in continuous mode. A sterilised activated sludge, spiked with 13 PAH at concentrations usually encountered in full-scale wastewater treatment plants, was used as substrate. The dry matter and volatile solid degradation, the biogas production rate and composition, the volatile fatty acids (VFA production and the PAH removals were monitored. Bacterial and archaeal communities were compared in abundance (qPCR, in community structure (SSCP fingerprinting and in dominant microbial species (454-pyrosequencing. The bioreactors inoculated with the community extracted from low contaminated anaerobic sludge showed the greater methane production. The PAH removals ranged from 10% to 30%, respectively, for high and low molecular weight PAH, whatever the inoculums tested, and were highly correlated with the dry matter and volatile solid removals. The microbial community structure and diversity differed with the inoculum source; this difference was maintained after the 100 days of digestion. However, the PAH removal was not correlated to these diverse structures and diversities. We hence obtained three functional stable consortia with two contrasted metabolic activities, and three different pictures of microbial diversity, but similar PAH and matter removals. These results confirm

  7. Similar PAH fate in anaerobic digesters inoculated with three microbial communities accumulating either volatile fatty acids or methane.

    Science.gov (United States)

    Braun, Florence; Hamelin, Jérôme; Bonnafous, Anaïs; Delgenès, Nadine; Steyer, Jean-Philippe; Patureau, Dominique

    2015-01-01

    Urban sludge produced on wastewater treatment plants are often contaminated by organic pollutants such as polycyclic aromatic hydrocarbons (PAH). Their removal under methanogenic conditions was already reported, but the factors influencing this removal remain unclear. Here, we determined the influence of microbial communities on PAH removal under controlled physico-chemical conditions. Twelve mesophilic anaerobic digesters were inoculated with three microbial communities extracted from ecosystems with contrasting pollution histories: a PAH contaminated soil, a PCB contaminated sediment and a low contaminated anaerobic sludge. These anaerobic digesters were operated during 100 days in continuous mode. A sterilised activated sludge, spiked with 13 PAH at concentrations usually encountered in full-scale wastewater treatment plants, was used as substrate. The dry matter and volatile solid degradation, the biogas production rate and composition, the volatile fatty acids (VFA) production and the PAH removals were monitored. Bacterial and archaeal communities were compared in abundance (qPCR), in community structure (SSCP fingerprinting) and in dominant microbial species (454-pyrosequencing). The bioreactors inoculated with the community extracted from low contaminated anaerobic sludge showed the greater methane production. The PAH removals ranged from 10% to 30%, respectively, for high and low molecular weight PAH, whatever the inoculums tested, and were highly correlated with the dry matter and volatile solid removals. The microbial community structure and diversity differed with the inoculum source; this difference was maintained after the 100 days of digestion. However, the PAH removal was not correlated to these diverse structures and diversities. We hence obtained three functional stable consortia with two contrasted metabolic activities, and three different pictures of microbial diversity, but similar PAH and matter removals. These results confirm that PAH removal

  8. The effects of chronic cadmium exposure on repeat swimming performance and anaerobic metabolism in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis).

    Science.gov (United States)

    Cunningham, Jessie L; McGeer, James C

    2016-04-01

    This study investigates the effect of chronic Cd exposure on the ability to perform repeat swim challenges in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis). Fish were exposed to waterborne Cd (18nM) in moderately hard water (120mgL(-1) CaCO3) for 30 days. This level of exposure has been shown to cause sublethal physiological disruption and acclimation responses but no impairment of sustained swimming capacity (Ucrit) in single swim challenges. Swim trials were done over the course of the exposure and each one consisted of an initial swim to 85% of the Ucrit of control fish, a 30min recovery period and finally a second swim challenge to determine Ucrit. Plasma and tissue samples were collected before and after each of the swim periods. As expected from previous studies, Cd exposure resulted in significant accumulation of Cd in gills, liver and kidney but not in white muscle. Exposure also induced a loss of plasma Ca followed by subsequent recovery (in lake whitefish but not brown trout) with few mortalities (100% survival for lake whitefish and 93% for brown trout). Both control and exposed fish swam to 85% of the single swim Ucrit and no differences in performance were seen. The Ucrit of unexposed controls in the second swim challenges were not different from the single swim Ucrit. However, second swim performance was significantly reduced in Cd exposed fish, particularly after a week of exposure where 31% and 38% reductions were observed for brown trout and lake whitefish respectively. Swimming to 85% Ucrit resulted in metabolic expenditure with little recovery after 30min. Few differences were observed between control and Cd exposed fish with the exception of a reduction in resting white muscle ATP stores of Cd exposed fish after 1 week of exposure. The results show that chronic sublethal Cd exposure results in an impairment of swimming ability in repeat swim challenges but this impairment is generally not related to metabolic processes

  9. Biochemistry and physiology of anaerobic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-05-18

    We welcome you to The Power of Anaerobes. This conference serves two purposes. One is to celebrate the life of Harry D. Peck, Jr.,who was born May 18, 1927 and would have celebrated his 73rd birthday at this conference. He died November 20, 1998. The second is to gather investigators to exchange views within the realm of anaerobic microbiology, an area in which tremendous progress has been seen during recent years. It is sufficient to mention discoveries of a new form of life (the archaea), hyper or extreme thermophiles, thermophilic alkaliphiles and anaerobic fungi. With these discoveries has come a new realization about physiological and metabolic properties of microorganisms, and this in turn has demonstrated their importance for the development, maintenance and sustenance of life on Earth.

  10. Rapid isolation of a facultative anaerobic electrochemically active bacterium capable of oxidizing acetate for electrogenesis and azo dyes reduction.

    Science.gov (United States)

    Shen, Nan; Yuan, Shi-Jie; Wu, Chao; Cheng, Yuan-Yuan; Song, Xiang-Ning; Li, Wen-Wei; Tong, Zhong-Hua; Yu, Han-Qing

    2014-05-01

    In this study, 27 strains of electrochemically active bacteria (EAB) were rapidly isolated and their capabilities of extracellular electron transfer were identified using a photometric method based on WO3 nanoclusters. These strains caused color change of WO3 from white to blue in a 24-well agar plate within 40 h. Most of the isolated EAB strains belonged to the genera of Aeromonas and Shewanella. One isolate, Pantoea agglomerans S5-44, was identified as an EAB that can utilize acetate as the carbon source to produce electricity and reduce azo dyes under anaerobic conditions. The results confirmed the capability of P. agglomerans S5-44 for extracellular electron transfer. The isolation of this acetate-utilizing, facultative EBA reveals the metabolic diversity of environmental bacteria. Such strains have great potential for environmental applications, especially at interfaces of aerobic and anaerobic environments, where acetate is the main available carbon source.

  11. Genome analysis coupled with physiological studies reveals a diverse nitrogen metabolism in Methylocystis sp. strain SC2.

    Directory of Open Access Journals (Sweden)

    Bomba Dam

    Full Text Available BACKGROUND: Methylocystis sp. strain SC2 can adapt to a wide range of methane concentrations. This is due to the presence of two isozymes of particulate methane monooxygenase exhibiting different methane oxidation kinetics. To gain insight into the underlying genetic information, its genome was sequenced and found to comprise a 3.77 Mb chromosome and two large plasmids. PRINCIPAL FINDINGS: We report important features of the strain SC2 genome. Its sequence is compared with those of seven other methanotroph genomes, comprising members of the Alphaproteobacteria, Gammaproteobacteria, and Verrucomicrobia. While the pan-genome of all eight methanotroph genomes totals 19,358 CDS, only 154 CDS are shared. The number of core genes increased with phylogenetic relatedness: 328 CDS for proteobacterial methanotrophs and 1,853 CDS for the three alphaproteobacterial Methylocystaceae members, Methylocystis sp. strain SC2 and strain Rockwell, and Methylosinus trichosporium OB3b. The comparative study was coupled with physiological experiments to verify that strain SC2 has diverse nitrogen metabolism capabilities. In correspondence to a full complement of 34 genes involved in N2 fixation, strain SC2 was found to grow with atmospheric N2 as the sole nitrogen source, preferably at low oxygen concentrations. Denitrification-mediated accumulation of 0.7 nmol (30N2/hr/mg dry weight of cells under anoxic conditions was detected by tracer analysis. N2 production is related to the activities of plasmid-borne nitric oxide and nitrous oxide reductases. CONCLUSIONS/PERSPECTIVES: Presence of a complete denitrification pathway in strain SC2, including the plasmid-encoded nosRZDFYX operon, is unique among known methanotrophs. However, the exact ecophysiological role of this pathway still needs to be elucidated. Detoxification of toxic nitrogen compounds and energy conservation under oxygen-limiting conditions are among the possible roles. Relevant features that may stimulate

  12. High-intensity exercise training increases the diversity and metabolic capacity of the mouse distal gut microbiota during diet-induced obesity.

    Science.gov (United States)

    Denou, Emmanuel; Marcinko, Katarina; Surette, Michael G; Steinberg, Gregory R; Schertzer, Jonathan D

    2016-06-01

    Diet and exercise underpin the risk of obesity-related metabolic disease. Diet alters the gut microbiota, which contributes to aspects of metabolic disease during obesity. Repeated exercise provides metabolic benefits during obesity. We assessed whether exercise could oppose changes in the taxonomic and predicted metagenomic characteristics of the gut microbiota during diet-induced obesity. We hypothesized that high-intensity interval training (HIIT) would counteract high-fat diet (HFD)-induced changes in the microbiota without altering obesity in mice. Compared with chow-fed mice, an obesity-causing HFD decreased the Bacteroidetes-to-Firmicutes ratio and decreased the genetic capacity in the fecal microbiota for metabolic pathways such as the tricarboxylic acid (TCA) cycle. After HFD-induced obesity was established, a subset of mice were HIIT for 6 wk, which increased host aerobic capacity but did not alter body or adipose tissue mass. The effects of exercise training on the microbiota were gut segment dependent and more extensive in the distal gut. HIIT increased the alpha diversity and Bacteroidetes/Firmicutes ratio of the distal gut and fecal microbiota during diet-induced obesity. Exercise training increased the predicted genetic capacity related to the TCA cycle among other aspects of metabolism. Strikingly, the same microbial metabolism indexes that were increased by exercise were all decreased in HFD-fed vs. chow diet-fed mice. Therefore, exercise training directly opposed some of the obesity-related changes in gut microbiota, including lower metagenomic indexes of metabolism. Some host and microbial pathways appeared similarly affected by exercise. These exercise- and diet-induced microbiota interactions can be captured in feces. Copyright © 2016 the American Physiological Society.

  13. Characterization and detection of a widely distributed gene cluster that predicts anaerobic choline utilization by human gut bacteria.

    Science.gov (United States)

    Martínez-del Campo, Ana; Bodea, Smaranda; Hamer, Hilary A; Marks, Jonathan A; Haiser, Henry J; Turnbaugh, Peter J; Balskus, Emily P

    2015-04-14

    Elucidation of the molecular mechanisms underlying the human gut microbiota's effects on health and disease has been complicated by difficulties in linking metabolic functions associated with the gut community as a whole to individual microorganisms and activities. Anaerobic microbial choline metabolism, a disease-associated metabolic pathway, exemplifies this challenge, as the specific human gut microorganisms responsible for this transformation have not yet been clearly identified. In this study, we established the link between a bacterial gene cluster, the choline utilization (cut) cluster, and anaerobic choline metabolism in human gut isolates by combining transcriptional, biochemical, bioinformatic, and cultivation-based approaches. Quantitative reverse transcription-PCR analysis and in vitro biochemical characterization of two cut gene products linked the entire cluster to growth on choline and supported a model for this pathway. Analyses of sequenced bacterial genomes revealed that the cut cluster is present in many human gut bacteria, is predictive of choline utilization in sequenced isolates, and is widely but discontinuously distributed across multiple bacterial phyla. Given that bacterial phylogeny is a poor marker for choline utilization, we were prompted to develop a degenerate PCR-based method for detecting the key functional gene choline TMA-lyase (cutC) in genomic and metagenomic DNA. Using this tool, we found that new choline-metabolizing gut isolates universally possessed cutC. We also demonstrated that this gene is widespread in stool metagenomic data sets. Overall, this work represents a crucial step toward understanding anaerobic choline metabolism in the human gut microbiota and underscores the importance of examining this microbial community from a function-oriented perspective. Anaerobic choline utilization is a bacterial metabolic activity that occurs in the human gut and is linked to multiple diseases. While bacterial genes responsible for

  14. Key players and team play: anaerobic microbial communities in hydrocarbon-contaminated aquifers.

    Science.gov (United States)

    Kleinsteuber, Sabine; Schleinitz, Kathleen M; Vogt, Carsten

    2012-05-01

    Biodegradation of anthropogenic pollutants in shallow aquifers is an important microbial ecosystem service which is mainly brought about by indigenous anaerobic microorganisms. For the management of contaminated sites, risk assessment and control of natural attenuation, the assessment of in situ biodegradation and the underlying microbial processes is essential. The development of novel molecular methods, "omics" approaches, and high-throughput techniques has revealed new insight into complex microbial communities and their functions in anoxic environmental systems. This review summarizes recent advances in the application of molecular methods to study anaerobic microbial communities in contaminated terrestrial subsurface ecosystems. We focus on current approaches to analyze composition, dynamics, and functional diversity of subsurface communities, to link identity to activity and metabolic function, and to identify the ecophysiological role of not yet cultured microbes and syntrophic consortia. We discuss recent molecular surveys of contaminated sites from an ecological viewpoint regarding degrader ecotypes, abiotic factors shaping anaerobic communities, and biotic interactions underpinning the importance of microbial cooperation for microbial ecosystem services such as contaminant degradation.

  15. Practice Patterns in Screening for Metabolic Disease in Women with PCOS of Diverse Race-Ethnic Backgrounds.

    Science.gov (United States)

    Mott, Melanie M; Kitos, Nicole R; Coviello, Andrea D

    2014-09-01

    Women with polycystic ovary syndrome (PCOS) are at high risk for metabolic disorders, which prompted the American Association of Clinical Endocrinologists (AACE) to publish a 2005 position statement recommending screening for metabolic disease.The purposes of the present study were to 1) to examine changes in screening rates for obesity, type 2 diabetes (T2D), metabolic syndrome (MetS), hyperlipidemia (HL), nonalcoholic fatty liver disease (NAFLD), and hypertension (HTN) in women with PCOS after publication of the 2005 AACE position statement and 2) to determine if screening rates and metabolic disorders vary by race-ethnicity. PCOS cases in 2006 (n = 547) and 2011 (n = 1,159) and metabolic disorders were identified by International Classification of Diseases, 9th revision (ICD9) code. Screening rates for metabolic disorders were determined by the presence of blood tests (hemoglobin A1c [HbA1c], lipid profile, alanine aminotransferase/aspartate aminotransferase [ALT/AST]). In 2006, ≤25% of PCOS patients underwent recommended screening tests: HbA1c 18%; lipid profile 11, only HbA1c testing had increased (18% to 21%). Obesity increased from 35% to 40%, while other metabolic disorders remained stable. Black women had the highest rates of obesity and HTN in 2011 (Obesity: Black 48%, Hispanic 44%, White 33%, Other 31%, P1; HTN: Black 18%, Hispanic 9%, White 10%, Other 7%, P1). Blacks and Hispanics were screened more often with ALT/AST testing (Black 27/27%, Hispanic 28/27%, White 23/22%, Other 17/18%, P = .02/.03). Screening rates were higher in the endocrine clinic for all metabolic disorders than in other clinics (P11.

  16. 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...

  17. Interspecies Variation of In Vitro Stability and Metabolic Diversity of YZG-331, a Promising Sedative-Hypnotic Compound

    Directory of Open Access Journals (Sweden)

    Zhihao Liu

    2017-08-01

    Full Text Available YZG-331, a synthetic adenosine derivative, express the sedative and hypnotic effects via binding to the adenosine receptor. The current study was taken to investigate the metabolic pathway of YZG-331 as well as species-specific differences in vitro. YZG-331 was reduced by 14, 11, 6, 46, and 11% within 120 min incubation in human, monkey, dog, rat, and mouse liver microsomes (LMs, respectively. However, YZG-331 was stable in human, monkey, dog, rat, and mouse liver cytoplasm. In addition, YZG-331 was unstable in rat or mouse gut microbiota with more than 50% of prototype drug degraded within 120 min incubation. Interestingly, the systemic exposure of M2 and M3 in rats and mice treated with antibiotics were significantly decreased in the pseudo germ-free group. YZG-331 could be metabolized in rat and human liver under the catalysis of CYP enzymes, and the metabolism showed species variation. In addition, 3 phase I metabolites were identified via hydroxyl (M1, hydrolysis (M2, or hydrolysis/ hydroxyl (M3 pathway. Flavin-containing monooxygenase 1 (FMO1 and FMO3 participated in the conversion of YZG-331 in rat LMs. Nevertheless, YZG-331 expressed stability with recombinant human FMOs, which further confirmed the species variation in the metabolism. Overall, these studies suggested that YZG-331 is not stable in LMs and gut microbiota. CYP450 enzymes and FMOs mediated the metabolism of YZG-331, and the metabolic pathway showed species difference. Special attention must be paid when extrapolating data from other species to humans.

  18. Microbial consortia involved in the anaerobic degradation of hydrocarbons.

    Science.gov (United States)

    Zwolinski; Harris, R F; Hickey, W J

    2000-01-01

    In this review, we examine the energetics of well-characterized biodegradation pathways and explore the possibilities for these to support growth of multiple organisms interacting in consortia. The relevant phenotypic and/or phylogenetic characteristics of isolates and consortia mediating hydrocarbon degradation coupled with different terminal electron-accepting processes (TEAP) are also reviewed. While the information on metabolic pathways has been gained from the analysis of individual isolates, the energetic framework presented here demonstrates that microbial consortia could be readily postulated for hydrocarbon degradation coupled to any TEAP. Several specialized reactions occur within these pathways, and the organisms mediating these are likely to play a key role in defining the hydrocarbon degradation characteristics of the community under a given TEAP. Comparing these processes within and between TEAPs reveals biological unity in that divergent phylotypes display similar degradation mechanisms and biological diversity in that hydrocarbon-degraders closely related as phylotypes differ in the type and variety of hydrocarbon degradation pathways they possess. Analysis of microcosms and of field samples suggests that we have only begun to reveal the diversity of organisms mediating anaerobic hydrocarbon degradation. Advancements in the understanding of how hydrocarbon-degrading communities function will be significantly affected by the extent to which organisms mediating specialized reactions can be identified, and tools developed to allow their study in situ.

  19. Anaerobic Digestion Foaming Causes

    OpenAIRE

    Ganidi, Nafsika

    2008-01-01

    Anaerobic digestion foaming has been encountered in several sewage treatment plants in the UK. Foaming has raised major concerns for the water utilities due to significant impacts on process efficiency and operational costs. Several foaming causes have been suggested over the past few years by researchers. However, the supporting experimental information is limited and in some cases site specific. The present report aimed to provide a better understanding of the anaerobic di...

  20. Aespoe Hard Rock Laboratory Canister Retrieval Test. Microorganisms in buffer from the Canister Retrieval Test - numbers and metabolic diversity

    Energy Technology Data Exchange (ETDEWEB)

    Lydmark, Sara; Pedersen, Karsten (Microbial Analytics Sweden AB (Sweden))

    2011-03-15

    bentonite is investigated, it is important that the sample procedures are accurate. Oxygen is toxic to many of the bacteria that thrive in anaerobic groundwater; among them are the sulphate-reducing bacteria. To avoid underestimation of the number of sulphate-reducing bacteria in the bentonite it is important to exclude oxygen during sampling. Therefore, the bentonite was at all occasions except one put in an anaerobic chamber shortly after arrival to the laboratory in Goeteborg a few hours after in-situ sampling. One bentonite block from the R9 level was not put in the anaerobic chamber until four days after sampling. Samples from this specific bentonite block were extracted 10-20 cm into the bentonite to, if possible, retain bentonite not exposed to oxygen. Another factor that may give underestimating results is desiccation. By wrapping the bentonite in sterile aluminium foil and plastic bags it was possible to avoid desiccation. The aluminium foil also served as protection against contamination of bacteria from the surroundings. The sampling procedures worked accurately. It was possible to sample the bentonite under sterile conditions, which was proved by the fact that bacteria only grew where the ambient conditions during storage in the CRT bentonite allowed this. Presence of sulphate-reducing bacteria proved that the bentonite was sampled without intrusion of oxygen in levels toxic to these organisms

  1. Aespoe Hard Rock Laboratory Canister Retrieval Test. Microorganisms in buffer from the Canister Retrieval Test - numbers and metabolic diversity

    International Nuclear Information System (INIS)

    Lydmark, Sara; Pedersen, Karsten

    2011-03-01

    is investigated, it is important that the sample procedures are accurate. Oxygen is toxic to many of the bacteria that thrive in anaerobic groundwater; among them are the sulphate-reducing bacteria. To avoid underestimation of the number of sulphate-reducing bacteria in the bentonite it is important to exclude oxygen during sampling. Therefore, the bentonite was at all occasions except one put in an anaerobic chamber shortly after arrival to the laboratory in Goeteborg a few hours after in-situ sampling. One bentonite block from the R9 level was not put in the anaerobic chamber until four days after sampling. Samples from this specific bentonite block were extracted 10-20 cm into the bentonite to, if possible, retain bentonite not exposed to oxygen. Another factor that may give underestimating results is desiccation. By wrapping the bentonite in sterile aluminium foil and plastic bags it was possible to avoid desiccation. The aluminium foil also served as protection against contamination of bacteria from the surroundings. The sampling procedures worked accurately. It was possible to sample the bentonite under sterile conditions, which was proved by the fact that bacteria only grew where the ambient conditions during storage in the CRT bentonite allowed this. Presence of sulphate-reducing bacteria proved that the bentonite was sampled without intrusion of oxygen in levels toxic to these organisms

  2. Hydroxylamine-dependent Anaerobic Ammonium Oxidation (Anammox) by “ Candidatus Brocadia sinica”

    KAUST Repository

    Oshiki, Mamoru; Ali, Muhammad; Shinyako-Hata, Kaori; Satoh, Hisashi; Okabe, Satoshi

    2016-01-01

    Although metabolic pathways and associated enzymes of anaerobic ammonium oxidation (anammox) of “Ca. Kuenenia stuttgartiensis” have been studied, those of other anammox bacteria are still poorly understood. NO2- reduction to NO is considered to be the first step in the anammox metabolism of “Ca. K. stuttgartiensis”, however, “Ca. Brocadia” lacks the genes that encode canonical NO-forming nitrite reductases (NirS or NirK) in its genome, which is different from “Ca. K. stuttgartiensis”. Here, we studied the anammox metabolism of “Ca. Brocadia sinica”. 15N-tracer experiments demonstrated that “Ca. B. sinica” cells could reduce NO2- to NH2OH, instead of NO, with as yet unidentified nitrite reductase(s). Furthermore, N2H4 synthesis, downstream reaction of NO2- reduction, was investigated using a purified “Ca. B. sinica” hydrazine synthase (Hzs) and intact cells. Both the “Ca. B. sinica” Hzs and cells utilized NH2OH and NH4+, but not NO and NH4+, for N2H4 synthesis and further oxidized N2H4 to N2 gas. Taken together, the metabolic pathway of “Ca. B. sinica” is NH2OH-dependent and different from the one of “Ca. K. stuttgartiensis”, indicating metabolic diversity of anammox bacteria. This article is protected by copyright. All rights reserved.

  3. Hydroxylamine-dependent anaerobic ammonium oxidation (anammox) by "Candidatus Brocadia sinica".

    Science.gov (United States)

    Oshiki, Mamoru; Ali, Muhammad; Shinyako-Hata, Kaori; Satoh, Hisashi; Okabe, Satoshi

    2016-09-01

    Although metabolic pathways and associated enzymes of anaerobic ammonium oxidation (anammox) of 'Ca. Kuenenia stuttgartiensis' have been studied, those of other anammox bacteria are still poorly understood. NO2- reduction to NO is considered to be the first step in the anammox metabolism of 'Ca. K. stuttgartiensis', however, 'Ca. Brocadia' lacks the genes that encode canonical NO-forming nitrite reductases (NirS or NirK) in its genome, which is different from 'Ca. K. stuttgartiensis'. Here, we studied the anammox metabolism of 'Ca. Brocadia sinica'. (15) N-tracer experiments demonstrated that 'Ca. B. sinica' cells could reduce NO2- to NH2 OH, instead of NO, with as yet unidentified nitrite reductase(s). Furthermore, N2 H4 synthesis, downstream reaction of NO2- reduction, was investigated using a purified 'Ca. B. sinica' hydrazine synthase (Hzs) and intact cells. Both the 'Ca. B. sinica' Hzs and cells utilized NH2 OH and NH4+, but not NO and NH4+, for N2 H4 synthesis and further oxidized N2 H4 to N2 gas. Taken together, the metabolic pathway of 'Ca. B. sinica' is NH2 OH-dependent and different from the one of 'Ca. K. stuttgartiensis', indicating metabolic diversity of anammox bacteria. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  4. Hydroxylamine-dependent Anaerobic Ammonium Oxidation (Anammox) by “ Candidatus Brocadia sinica”

    KAUST Repository

    Oshiki, Mamoru

    2016-04-26

    Although metabolic pathways and associated enzymes of anaerobic ammonium oxidation (anammox) of “Ca. Kuenenia stuttgartiensis” have been studied, those of other anammox bacteria are still poorly understood. NO2- reduction to NO is considered to be the first step in the anammox metabolism of “Ca. K. stuttgartiensis”, however, “Ca. Brocadia” lacks the genes that encode canonical NO-forming nitrite reductases (NirS or NirK) in its genome, which is different from “Ca. K. stuttgartiensis”. Here, we studied the anammox metabolism of “Ca. Brocadia sinica”. 15N-tracer experiments demonstrated that “Ca. B. sinica” cells could reduce NO2- to NH2OH, instead of NO, with as yet unidentified nitrite reductase(s). Furthermore, N2H4 synthesis, downstream reaction of NO2- reduction, was investigated using a purified “Ca. B. sinica” hydrazine synthase (Hzs) and intact cells. Both the “Ca. B. sinica” Hzs and cells utilized NH2OH and NH4+, but not NO and NH4+, for N2H4 synthesis and further oxidized N2H4 to N2 gas. Taken together, the metabolic pathway of “Ca. B. sinica” is NH2OH-dependent and different from the one of “Ca. K. stuttgartiensis”, indicating metabolic diversity of anammox bacteria. This article is protected by copyright. All rights reserved.

  5. Status of carbohydrate and lipid metabolism in obese patients with type 2 diabetes mellitus after biliopancreatic diversion surgery

    Directory of Open Access Journals (Sweden)

    2013-10-01

    Full Text Available We examined 70 patients with obesity and diabetes mellitus type 2 before and within 5 years after BPD: these patients showed a significant improvement in the status of carbohydrate and lipid metabolism within 3 months after surgery. This improvement has remained stable along with the reduced body weight during the whole observation period of up to 5 years.

  6. Cyanobacterial life at low O(2): community genomics and function reveal metabolic versatility and extremely low diversity in a Great Lakes sinkhole mat.

    Science.gov (United States)

    Voorhies, A A; Biddanda, B A; Kendall, S T; Jain, S; Marcus, D N; Nold, S C; Sheldon, N D; Dick, G J

    2012-05-01

    Cyanobacteria are renowned as the mediators of Earth's oxygenation. However, little is known about the cyanobacterial communities that flourished under the low-O(2) conditions that characterized most of their evolutionary history. Microbial mats in the submerged Middle Island Sinkhole of Lake Huron provide opportunities to investigate cyanobacteria under such persistent low-O(2) conditions. Here, venting groundwater rich in sulfate and low in O(2) supports a unique benthic ecosystem of purple-colored cyanobacterial mats. Beneath the mat is a layer of carbonate that is enriched in calcite and to a lesser extent dolomite. In situ benthic metabolism chambers revealed that the mats are net sinks for O(2), suggesting primary production mechanisms other than oxygenic photosynthesis. Indeed, (14)C-bicarbonate uptake studies of autotrophic production show variable contributions from oxygenic and anoxygenic photosynthesis and chemosynthesis, presumably because of supply of sulfide. These results suggest the presence of either facultatively anoxygenic cyanobacteria or a mix of oxygenic/anoxygenic types of cyanobacteria. Shotgun metagenomic sequencing revealed a remarkably low-diversity mat community dominated by just one genotype most closely related to the cyanobacterium Phormidium autumnale, for which an essentially complete genome was reconstructed. Also recovered were partial genomes from a second genotype of Phormidium and several Oscillatoria. Despite the taxonomic simplicity, diverse cyanobacterial genes putatively involved in sulfur oxidation were identified, suggesting a diversity of sulfide physiologies. The dominant Phormidium genome reflects versatile metabolism and physiology that is specialized for a communal lifestyle under fluctuating redox conditions and light availability. Overall, this study provides genomic and physiologic insights into low-O(2) cyanobacterial mat ecosystems that played crucial geobiological roles over long stretches of Earth history.

  7. Anaerobic prosthetic joint infection.

    Science.gov (United States)

    Shah, Neel B; Tande, Aaron J; Patel, Robin; Berbari, Elie F

    2015-12-01

    In an effort to improve mobility and alleviate pain from degenerative and connective tissue joint disease, an increasing number of individuals are undergoing prosthetic joint replacement in the United States. Joint replacement is a highly effective intervention, resulting in improved quality of life and increased independence [1]. By 2030, it is predicted that approximately 4 million total hip and knee arthroplasties will be performed yearly in the United States [2]. One of the major complications associated with this procedure is prosthetic joint infection (PJI), occurring at a rate of 1-2% [3-7]. In 2011, the Musculoskeletal Infectious Society created a unifying definition for prosthetic joint infection [8]. The following year, the Infectious Disease Society of America published practice guidelines that focused on the diagnosis and management of PJI. These guidelines focused on the management of commonly encountered organisms associated with PJI, including staphylococci, streptococci and select aerobic Gram-negative bacteria. However, with the exception of Propionibacterium acnes, management of other anaerobic organisms was not addressed in these guidelines [1]. Although making up approximately 3-6% of PJI [9,10], anaerobic microorganisms cause devastating complications, and similar to the more common organisms associated with PJI, these bacteria also result in significant morbidity, poor outcomes and increased health-care costs. Data on diagnosis and management of anaerobic PJI is mostly derived from case reports, along with a few cohort studies [3]. There is a paucity of published data outlining factors associated with risks, diagnosis and management of anaerobic PJI. We therefore reviewed available literature on anaerobic PJI by systematically searching the PubMed database, and collected data from secondary searches to determine information on pathogenesis, demographic data, clinical features, diagnosis and management. We focused our search on five commonly

  8. Exocellular electron transfer in anaerobic microbial communities.

    Science.gov (United States)

    Stams, Alfons J M; de Bok, Frank A M; Plugge, Caroline M; van Eekert, Miriam H A; Dolfing, Jan; Schraa, Gosse

    2006-03-01

    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 syntrophic consortia of proton-reducing acetogenic bacteria and hydrogen-consuming methanogenic archaea. Anaerobic microorganisms that use insoluble electron acceptors for growth, such as iron- and manganese-oxide as well as inert graphite electrodes in microbial fuel cells, also transfer electrons exocellularly. Soluble compounds, like humic substances, quinones, phenazines and riboflavin, can function as exocellular electron mediators enhancing this type of anaerobic respiration. However, direct electron transfer by cell-cell contact is important as well. This review addresses the mechanisms of exocellular electron transfer in anaerobic microbial communities. There are fundamental differences but also similarities between electron transfer to another microorganism or to an insoluble electron acceptor. The physical separation of the electron donor and electron acceptor metabolism allows energy conservation in compounds as methane and hydrogen or as electricity. Furthermore, this separation is essential in the donation or acceptance of electrons in some environmental technological processes, e.g. soil remediation, wastewater purification and corrosion.

  9. Anaerobic halo- alkaliphilic bacterial community of athalassic, hypersaline Mono lake and Owens Lake in California

    Science.gov (United States)

    Pikuta, Elena V.; Detkova, Ekaterina N.; Bej, Asim K.; Marsic, Damien; Hoover, Richard B.

    2003-02-01

    The bacterial diversity of microbial extremophiles from the meromictic, hypersaline Mono Lake and a small evaporite pool in Owens Lake of California was studied. In spite of these regions had differing mineral background and different concentrations of NaCl in water they contain the same halo- alkaliphiles anaerobic bacterial community. Three new species of bacteria were detected in this community: primary anaerobe, dissipotrophic saccharolytic spirochete Spirochaeta americana strain AspG1T, primary anaerobe which is proteolytic Tindallia californiensis strain APOT, and secondary anaerobe, hydrogen using Desulfonatronum thiodismutans strain MLF1T, which is sulfate- reducer with chemo-litho-autotrophic metabolism. All of these bacteria are obligate alkaliphiles and dependent upon Na+ ions and CO32- ions in growth mediums. It is interesting that closest relationships for two of these species were isolates from samples of equatorial African soda Magadi lake: Spirochaeta americana AspG1T has 99.4% similarity on 16S rDNA- analyses with Spirochaeta alkalica Z- 7491T, and Tindallia californiensis APOT has 99.1% similarity with Tindallia magadiensis Z-7934T. But result of DNA-DNA- hybridization demonstrated less then 50% similarity between Spirochaeta americana AspG1T and Spirochaeta alkalica Z-7491T. Percent of homology between Tindallia californiensis APOT and Tindallia magadiensis Z-7934T is only 55%. The sulfate-reducer from the alkalic anaerobic community of Magadi lake Desulfonatronovibrio hydrogenovorans Z-7935T was phylogenetically distant from this sulfate-reducer in Mono lake, but genetically closer (99.7% similarity) to the sulfate-reducer, isolated from Central Asian alkalic lake Khadyn in Siberia Desulfonatronum lacustre Z-7951T. The study of key enzymes (hydrogenase and CO- hydrogenase) in Tindallia californiensis APOT and Desulfonatronum thiodismutans MLF1T showed the presence of high activity of both the enzymes in first and only hydrogenase in second

  10. Effects of Pheretima Guillelmi Cultivation Time on Microbial Community Diversity and Characteristics of Carbon Metabolism in Vegetable Soil

    Directory of Open Access Journals (Sweden)

    ZHENG Xian-qing

    2015-12-01

    Full Text Available In order to study the effect of different biological tillage time (Pheretima guillelmi on soil microbial community metabolic functions in different soil depths, we set a location test in vegetable field at Chongming Island in Shanghai to analyze the changes of soil microbial community and carbon utilization abilities (Average well- color development, AWCD by using biolog eco-plate method. The three-year results showed that: Bio-tillage significantly improved microbial community activity, and with the increase of tillage years, biological tillage could make the average AWCD 3 to 7 times higher. The Simpson index and Shannon index of the biological tillage treatments were significantly higher than that of the control. The cumulative increase of 0~5 cm soil layer was 49 and 6.28 respectively, and the cumulative increase of 5~20 cm soil layer was 31 and 2.55 respectively. Earthworm bio-tillage significantly increased the soil microbial metabolic ability of 6 kinds of carbon sources, and increased the carbohydrate metabolism activity. In this study, earthworm bio-tillage is an effective way to increase the microbial activity of microbial soil.

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

    Science.gov (United States)

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

    2016-01-01

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

  12. Metagenomic approach reveals microbial diversity and predictive microbial metabolic pathways in Yucha, a traditional Li fermented food

    OpenAIRE

    Zhang, Jiachao; Wang, Xiaoru; Huo, Dongxue; Li, Wu; Hu, Qisong; Xu, Chuanbiao; Liu, Sixin; Li, Congfa

    2016-01-01

    Yucha is a typical traditional fermented food of the Li population in the Hainan province of China, and it is made up of cooked rice and fresh fish. In the present study, metagenomic approach and culture-dependent technology were applied to describe the diversity of microbiota and identify beneficial microbes in the Yucha. At the genus level, Lactobacillus was the most abundant genus (43.82% of the total reads), followed by Lactococcus, Enterococcus, Vibrio, Weissella, Pediococcus, Enterobact...

  13. Anaerobes in bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Aggarwal A

    2003-01-01

    Full Text Available Four hundred high vaginal swabs were taken from patients attending gynaecology and obstetrics department of Govt. medical college, Amritsar. The patients were divided into four groups i.e. women in pregnancy (Group I, in labour/post partum (Group II, with abnormal vaginal discharge or bacterial vaginosis (Group III and asymptomatic women as control (Group IV. Anaerobic culture of vaginal swabs revealed that out of 400 cases, 212(53% were culture positive. Maximum isolation of anaerobes was in group III (84% followed by group II (56%, group I (36% and control group (15%. Gram positive anaerobes (69.2% out numbered gram negatives (30.8%. Among various isolates Peptostreptococcus spp. and Bacteroides spp. were predominant.

  14. Contribution of anaerobic energy expenditure to whole body thermogenesis

    Directory of Open Access Journals (Sweden)

    Scott Christopher B

    2005-06-01

    Full Text Available Abstract Heat production serves as the standard measurement for the determination of energy expenditure and efficiency in animals. Estimations of metabolic heat production have traditionally focused on gas exchange (oxygen uptake and carbon dioxide production although direct heat measurements may include an anaerobic component particularly when carbohydrate is oxidized. Stoichiometric interpretations of the ratio of carbon dioxide production to oxygen uptake suggest that both anaerobic and aerobic heat production and, by inference, all energy expenditure – can be accounted for with a measurement of oxygen uptake as 21.1 kJ per liter of oxygen. This manuscript incorporates contemporary bioenergetic interpretations of anaerobic and aerobic ATP turnover to promote the independence of these disparate types of metabolic energy transfer: each has different reactants and products, uses dissimilar enzymes, involves different types of biochemical reactions, takes place in separate cellular compartments, exploits different types of gradients and ultimately each operates with distinct efficiency. The 21.1 kJ per liter of oxygen for carbohydrate oxidation includes a small anaerobic heat component as part of anaerobic energy transfer. Faster rates of ATP turnover that exceed mitochondrial respiration and that are supported by rapid glycolytic phosphorylation with lactate production result in heat production that is independent of oxygen uptake. Simultaneous direct and indirect calorimetry has revealed that this anaerobic heat does not disappear when lactate is later oxidized and so oxygen uptake does not adequately measure anaerobic efficiency or energy expenditure (as was suggested by the "oxygen debt" hypothesis. An estimate of anaerobic energy transfer supplements the measurement of oxygen uptake and may improve the interpretation of whole-body energy expenditure.

  15. Perspectives for anaerobic digestion

    DEFF Research Database (Denmark)

    Ahring, Birgitte Kiær

    2003-01-01

    The modern society generates large amounts of waste that represent a tremendous threat to the environment and human and animal health. To prevent and control this, a range of different waste treatment and disposal methods are used. The choice of method must always be based on maximum safety...... to the soil. Anaerobic digestion (AD) is one way of achieving this goal and it will furthermore, reduce energy consumption or may even be net energy producing. This chapter aims at provide a basic understanding of the world in which anaerobic digestion is operating today. The newest process developments...

  16. Bacterial ecology of abattoir wastewater treated by an anaerobic digestor

    Directory of Open Access Journals (Sweden)

    Linda Jabari

    2016-03-01

    Full Text Available Abstract Wastewater from an anaerobic treatment plant at a slaughterhouse was analysed to determine the bacterial biodiversity present. Molecular analysis of the anaerobic sludge obtained from the treatment plant showed significant diversity, as 27 different phyla were identified. Firmicutes, Proteobacteria, Bacteroidetes, Thermotogae, Euryarchaeota (methanogens, and msbl6 (candidate division were the dominant phyla of the anaerobic treatment plant and represented 21.7%, 18.5%, 11.5%, 9.4%, 8.9%, and 8.8% of the total bacteria identified, respectively. The dominant bacteria isolated were Clostridium, Bacteroides, Desulfobulbus, Desulfomicrobium, Desulfovibrio and Desulfotomaculum. Our results revealed the presence of new species, genera and families of microorganisms. The most interesting strains were characterised. Three new bacteria involved in anaerobic digestion of abattoir wastewater were published.

  17. Bacterial ecology of abattoir wastewater treated by an anaerobic digestor.

    Science.gov (United States)

    Jabari, Linda; Gannoun, Hana; Khelifi, Eltaief; Cayol, Jean-Luc; Godon, Jean-Jacques; Hamdi, Moktar; Fardeau, Marie-Laure

    2016-01-01

    Wastewater from an anaerobic treatment plant at a slaughterhouse was analysed to determine the bacterial biodiversity present. Molecular analysis of the anaerobic sludge obtained from the treatment plant showed significant diversity, as 27 different phyla were identified. Firmicutes, Proteobacteria, Bacteroidetes, Thermotogae, Euryarchaeota (methanogens), and msbl6 (candidate division) were the dominant phyla of the anaerobic treatment plant and represented 21.7%, 18.5%, 11.5%, 9.4%, 8.9%, and 8.8% of the total bacteria identified, respectively. The dominant bacteria isolated were Clostridium, Bacteroides, Desulfobulbus, Desulfomicrobium, Desulfovibrio and Desulfotomaculum. Our results revealed the presence of new species, genera and families of microorganisms. The most interesting strains were characterised. Three new bacteria involved in anaerobic digestion of abattoir wastewater were published. Copyright © 2015 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  18. My Lifelong Passion for Biochemistry and Anaerobic Microorganisms.

    Science.gov (United States)

    Thauer, Rudolf Kurt

    2015-01-01

    Early parental influence led me first to medical school, but after developing a passion for biochemistry and sensing the need for a deeper foundation, I changed to chemistry. During breaks between semesters, I worked in various biochemistry labs to acquire a feeling for the different areas of investigation. The scientific puzzle that fascinated me most was the metabolism of the anaerobic bacterium Clostridium kluyveri, which I took on in 1965 in Karl Decker's lab in Freiburg, Germany. I quickly realized that little was known about the biochemistry of strict anaerobes such as clostridia, methanogens, acetogens, and sulfate-reducing bacteria and that these were ideal model organisms to study fundamental questions of energy conservation, CO2 fixation, and the evolution of metabolic pathways. My passion for anaerobes was born then and is unabated even after 50 years of study.

  19. Genome Analysis of a Limnobacter sp. Identified in an Anaerobic Methane-Consuming Cell Consortium

    OpenAIRE

    Chen, Ying; Feng, Xiaoyuan; He, Ying; Wang, Fengping

    2016-01-01

    Species of Limnobacter genus are widespread in a variety of environments, yet knowledges upon their metabolic potentials and mechanisms of environmental adaptation are limited. In this study, a cell aggregate containing Limnobacter and anaerobic methanotrophic archaea (ANME) was captured from an enriched anaerobic methane oxidizing (AOM) microbial community. A genomic bin of Limnobacter was obtained and analyzed, which provides the first metabolic insights into Limnobacter from an AOM environ...

  20. Genome analysis of a Limnobacter sp. identified in an anaerobic methane-consuming cell consortium

    OpenAIRE

    Ying Chen; Ying Chen; Ying Chen; Xiaoyuan Feng; Xiaoyuan Feng; Ying He; Ying He; Fengping Wang; Fengping Wang

    2016-01-01

    Species of Limnobacter genus are widespread in a variety of environments, yet knowledges upon their metabolic potentials and mechanisms of environmental adaptation are limited. In this study, a cell aggregate containing Limnobacter and anaerobic methanotrophic archaea (ANME) was captured from an enriched anaerobic methane oxidizing (AOM) microbial community. A genomic bin of Limnobacter was obtained and analyzed, which provides the first metabolic insights into Limnobacter from an AOM environ...

  1. Direct detection of diverse metabolic changes in virally transformed and tax-expressing cells by mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Prabhakar Sripadi

    Full Text Available BACKGROUND: Viral transformation of a cell starts at the genetic level, followed by changes in the proteome and the metabolome of the host. There is limited information on the broad metabolic changes in HTLV transformed cells. METHODS AND PRINCIPAL FINDINGS: Here, we report the detection of key changes in metabolites and lipids directly from human T-lymphotropic virus type 1 and type 3 (HTLV1 and HTLV3 transformed, as well as Tax1 and Tax3 expressing cell lines by laser ablation electrospray ionization (LAESI mass spectrometry (MS. Comparing LAESI-MS spectra of non-HTLV1 transformed and HTLV1 transformed cells revealed that glycerophosphocholine (PC lipid components were dominant in the non-HTLV1 transformed cells, and PC(O-32:1 and PC(O-34:1 plasmalogens were displaced by PC(30:0 and PC(32:0 species in the HTLV1 transformed cells. In HTLV1 transformed cells, choline, phosphocholine, spermine and glutathione, among others, were downregulated, whereas creatine, dopamine, arginine and AMP were present at higher levels. When comparing metabolite levels between HTLV3 and Tax3 transfected 293T cells, there were a number of common changes observed, including decreased choline, phosphocholine, spermine, homovanillic acid, and glycerophosphocholine and increased spermidine and N-acetyl aspartic acid. These results indicate that the lipid metabolism pathway as well as the creatine and polyamine biosynthesis pathways are commonly deregulated after expression of HTLV3 and Tax3, indicating that the noted changes are likely due to Tax3 expression. N-acetyl aspartic acid is a novel metabolite that is upregulated in all cell types and all conditions tested. CONCLUSIONS AND SIGNIFICANCE: We demonstrate the high throughput in situ metabolite profiling of HTLV transformed and Tax expressing cells, which facilitates the identification of virus-induced perturbations in the biochemical processes of the host cells. We found virus type-specific (HTLV1 vs. HTLV3

  2. Direct detection of diverse metabolic changes in virally transformed and tax-expressing cells by mass spectrometry.

    Science.gov (United States)

    Sripadi, Prabhakar; Shrestha, Bindesh; Easley, Rebecca L; Carpio, Lawrence; Kehn-Hall, Kylene; Chevalier, Sebastien; Mahieux, Renaud; Kashanchi, Fatah; Vertes, Akos

    2010-09-07

    Viral transformation of a cell starts at the genetic level, followed by changes in the proteome and the metabolome of the host. There is limited information on the broad metabolic changes in HTLV transformed cells. Here, we report the detection of key changes in metabolites and lipids directly from human T-lymphotropic virus type 1 and type 3 (HTLV1 and HTLV3) transformed, as well as Tax1 and Tax3 expressing cell lines by laser ablation electrospray ionization (LAESI) mass spectrometry (MS). Comparing LAESI-MS spectra of non-HTLV1 transformed and HTLV1 transformed cells revealed that glycerophosphocholine (PC) lipid components were dominant in the non-HTLV1 transformed cells, and PC(O-32:1) and PC(O-34:1) plasmalogens were displaced by PC(30:0) and PC(32:0) species in the HTLV1 transformed cells. In HTLV1 transformed cells, choline, phosphocholine, spermine and glutathione, among others, were downregulated, whereas creatine, dopamine, arginine and AMP were present at higher levels. When comparing metabolite levels between HTLV3 and Tax3 transfected 293T cells, there were a number of common changes observed, including decreased choline, phosphocholine, spermine, homovanillic acid, and glycerophosphocholine and increased spermidine and N-acetyl aspartic acid. These results indicate that the lipid metabolism pathway as well as the creatine and polyamine biosynthesis pathways are commonly deregulated after expression of HTLV3 and Tax3, indicating that the noted changes are likely due to Tax3 expression. N-acetyl aspartic acid is a novel metabolite that is upregulated in all cell types and all conditions tested. We demonstrate the high throughput in situ metabolite profiling of HTLV transformed and Tax expressing cells, which facilitates the identification of virus-induced perturbations in the biochemical processes of the host cells. We found virus type-specific (HTLV1 vs. HTLV3), expression-specific (Tax1 vs. Tax3) and cell-type-specific (T lymphocytes vs. kidney

  3. High-throughput metabolic profiling of diverse green Coffea arabica beans identified tryptophan as a universal discrimination factor for immature beans.

    Science.gov (United States)

    Setoyama, Daiki; Iwasa, Keiko; Seta, Harumichi; Shimizu, Hiroaki; Fujimura, Yoshinori; Miura, Daisuke; Wariishi, Hiroyuki; Nagai, Chifumi; Nakahara, Koichi

    2013-01-01

    The maturity of green coffee beans is the most influential determinant of the quality and flavor of the resultant coffee beverage. However, the chemical compounds that can be used to discriminate the maturity of the beans remain uncharacterized. We herein analyzed four distinct stages of maturity (immature, semi-mature, mature and overripe) of nine different varieties of green Coffea arabica beans hand-harvested from a single experimental field in Hawaii. After developing a high-throughput experimental system for sample preparation and liquid chromatography-mass spectrometry (LC-MS) measurement, we applied metabolic profiling, integrated with chemometric techniques, to explore the relationship between the metabolome and maturity of the sample in a non-biased way. For the multivariate statistical analyses, a partial least square (PLS) regression model was successfully created, which allowed us to accurately predict the maturity of the beans based on the metabolomic information. As a result, tryptophan was identified to be the best contributor to the regression model; the relative MS intensity of tryptophan was higher in immature beans than in those after the semi-mature stages in all arabica varieties investigated, demonstrating a universal discrimination factor for diverse arabica beans. Therefore, typtophan, either alone or together with other metabolites, may be utilized for traders as an assessment standard when purchasing qualified trading green arabica bean products. Furthermore, our results suggest that the tryptophan metabolism may be tightly linked to the development of coffee cherries and/or beans.

  4. Proteomic analysis of maize grain development using iTRAQ reveals temporal programs of diverse metabolic processes.

    Science.gov (United States)

    Yu, Tao; Li, Geng; Dong, Shuting; Liu, Peng; Zhang, Jiwang; Zhao, Bin

    2016-11-04

    Grain development in maize is an essential process in the plant's life cycle and is vital for use of the plant as a crop for animals and humans. However, little is known regarding the protein regulatory networks that control grain development. Here, isobaric tag for relative and absolute quantification (iTRAQ) technology was used to analyze temporal changes in protein expression during maize grain development. Maize grain proteins and changes in protein expression at eight developmental stages from 3 to 50 d after pollination (DAP) were performed using iTRAQ-based proteomics. Overall, 4751 proteins were identified; 2639 of these were quantified and 1235 showed at least 1.5-fold changes in expression levels at different developmental stages and were identified as differentially expressed proteins (DEPs). The DEPs were involved in different cellular and metabolic processes with a preferential distribution to protein synthesis/destination and metabolism categories. A K-means clustering analysis revealed coordinated protein expression associated with different functional categories/subcategories at different development stages. Our results revealed developing maize grain display different proteomic characteristics at distinct stages, such as numerous DEPs for cell growth/division were highly expressed during early stages, whereas those for starch biosynthesis and defense/stress accumulated in middle and late stages, respectively. We also observed coordinated expression of multiple proteins of the antioxidant system, which are essential for the maintenance of reactive oxygen species (ROS) homeostasis during grain development. Particularly, some DEPs, such as zinc metallothionein class II, pyruvate orthophosphate dikinase (PPDK) and 14-3-3 proteins, undergo major changes in expression at specific developmental stages, suggesting their roles in maize grain development. These results provide a valuable resource for analyzing protein function on a global scale and also

  5. Bio digester : anaerobic methanogenesis

    NARCIS (Netherlands)

    Bullema, Marten; Hulzen, Hans; Keizer, Melvin; Pruisscher, Gerlof; Smint, Martin; Vincent, Helene

    2014-01-01

    As part of the theme 13 and 14, our group have to realize a project in the field of the renewable energy. This project consist of the design of a bio-digester for the canteen of Zernikeplein. Gert Hofstede is our client. To produce energy, a bio-digester uses the anaerobic digestion, which is made

  6. Anaerobic biotransformation of estrogens

    International Nuclear Information System (INIS)

    Czajka, Cynthia P.; Londry, Kathleen L.

    2006-01-01

    Estrogens are important environmental contaminants that disrupt endocrine systems and feminize male fish. We investigated the potential for anaerobic biodegradation of the estrogens 17-α-ethynylestradiol (EE2) and 17-β-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 μg L -1 day -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-α-estradiol under all but nitrate-reducing conditions. Although E2 could be readily transformed to E1 and in many cases 17-α-estradiol under anaerobic conditions, the complete degradation of estrogens under these conditions was minimal, suggesting that they would accumulate in anoxic environments

  7. Anaerobic treatment in Italy

    Energy Technology Data Exchange (ETDEWEB)

    Del Borghi, M; Solisio, C; Ferrailo, G

    1984-02-01

    In Italy, environmental protection and energy conservation have become very important since the increase in oil prices. The law requires that all waste waters have a B.O.D. of 40 mg/l by 1986 so there has been an expansion of purification plants since 1976, using anaerobic digestion. The report deals with the current state of anaerobic treatment in Italy with particular reference to (1) animal wastes. In intensive holdings, anaerobic digestion leads to a decrease in pollution and an increase in biogas generation which can be used to cover the energy demand of the process. The factors which influence the builders of digestors for farms are considered. (2) Non toxic industrial wastes. These are the waste waters emanating from the meat packing, brewing, pharmaceutical and chemical industries. Particular reference is made to the distillery plants using anaerobic treatment prior to aerobic digestion. (3) Urban wastes. The advantages and the disadvantages are considered and further research and development is recommended. 20 references.

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

    Directory of Open Access Journals (Sweden)

    C. Jeanthon

    2011-07-01

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

  9. Physiologically anaerobic microorganisms of the deep subsurface. Progress report, June 1, 1990--May 30, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, S.E. Jr.; Chung, K.T.

    1991-06-01

    This study seeks to determine numbers, diversity, and morphology of anaerobic microorganisms in 15 samples of subsurface material from the Idaho National Engineering Laboratory, in 18 samples from the Hanford Reservation and in 1 rock sample from the Nevada Test Site; set up long term experiments on the chemical activities of anaerobic microorganisms based on these same samples; work to improve methods for the micro-scale determination of in situ anaerobic microbial activity;and to begin to isolate anaerobes from these samples into axenic culture with identification of the axenic isolates.

  10. Anaerobic biological treatment

    International Nuclear Information System (INIS)

    Speece, R.E.

    1990-01-01

    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 CH 4 and CO 2 . 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

  11. Peatland Acidobacteria with a dissimilatory sulfur metabolism.

    Science.gov (United States)

    Hausmann, Bela; Pelikan, Claus; Herbold, Craig W; Köstlbacher, Stephan; Albertsen, Mads; Eichorst, Stephanie A; Glavina Del Rio, Tijana; Huemer, Martin; Nielsen, Per H; Rattei, Thomas; Stingl, Ulrich; Tringe, Susannah G; Trojan, Daniela; Wentrup, Cecilia; Woebken, Dagmar; Pester, Michael; Loy, Alexander

    2018-02-23

    Sulfur-cycling microorganisms impact organic matter decomposition in wetlands and consequently greenhouse gas emissions from these globally relevant environments. However, their identities and physiological properties are largely unknown. By applying a functional metagenomics approach to an acidic peatland, we recovered draft genomes of seven novel Acidobacteria species with the potential for dissimilatory sulfite (dsrAB, dsrC, dsrD, dsrN, dsrT, dsrMKJOP) or sulfate respiration (sat, aprBA, qmoABC plus dsr genes). Surprisingly, the genomes also encoded DsrL, which so far was only found in sulfur-oxidizing microorganisms. Metatranscriptome analysis demonstrated expression of acidobacterial sulfur-metabolism genes in native peat soil and their upregulation in diverse anoxic microcosms. This indicated an active sulfate respiration pathway, which, however, might also operate in reverse for dissimilatory sulfur oxidation or disproportionation as proposed for the sulfur-oxidizing Desulfurivibrio alkaliphilus. Acidobacteria that only harbored genes for sulfite reduction additionally encoded enzymes that liberate sulfite from organosulfonates, which suggested organic sulfur compounds as complementary energy sources. Further metabolic potentials included polysaccharide hydrolysis and sugar utilization, aerobic respiration, several fermentative capabilities, and hydrogen oxidation. Our findings extend both, the known physiological and genetic properties of Acidobacteria and the known taxonomic diversity of microorganisms with a DsrAB-based sulfur metabolism, and highlight new fundamental niches for facultative anaerobic Acidobacteria in wetlands based on exploitation of inorganic and organic sulfur molecules for energy conservation.

  12. Bacterial diversity exploration in hydrocarbon polluted soil: metabolic potential and degrader community evolution revealed by isotope labeling

    International Nuclear Information System (INIS)

    Martin, F.

    2011-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous compounds produced by incomplete combustion of organic matter. They are a source of environmental pollution, especially associated to oil product exploitation, and represent a threat for living organisms including human beings because of their toxicity. Many bacteria capable of degrading PAHs have been isolated and studied. However, since less than 5% of soil bacteria can be cultivated in the laboratory, bacterial species able to degrade PAHs in situ have been poorly studied. The first goal of this study was to identify bacteria that degrade PAHs in soil using culture-independent molecular methods. To this end, a strategy known a stable isotope probing has been implemented based on the use of phenanthrene, a three rings PAH, in which the natural isotope of carbon was replaced by 13 C. This molecule has been introduced as a tracer in microcosms containing soil from a constructed wetlands collecting contaminated water from highway runoff. Bacteria having incorporated the 13 C were then identified by 16 S rRNA gene sequence analysis after PCR amplification from labeled genomic DNA extracted from soil. The results show that so far little studied Betaproteobacteria, belonging to the genera Acidovorax, Rhodoferax, Hydrogenophaga and Thiobacillus, as well as Rhodocyclaceae, were the key players in phenanthrene degradation. Predominance of Betaproteobacteries was established thanks to quantitative PCR measurements. A dynamic analysis of bacterial diversity also showed that the community structure of degraders depended on phenanthrene bioavailability. In addition, the phylogenetic diversity of ring-hydroxylating di-oxygenases, enzymes involved in the first step of PAH degradation, has been explored. We detected new sequences, mostly related to di-oxygenases from Sphingomonadales and Burkholderiales. For the first time, we were able to associate a catalytic activity for oxidation of PAHs to partial gene sequences

  13. Phylloplane bacteria of Jatropha curcas: diversity, metabolic characteristics, and growth-promoting attributes towards vigor of maize seedling.

    Science.gov (United States)

    Dubey, Garima; Kollah, Bharati; Ahirwar, Usha; Mandal, Asit; Thakur, Jyoti Kumar; Patra, Ashok Kumar; Mohanty, Santosh Ranjan

    2017-10-01

    The complex role of phylloplane microorganisms is less understood than that of rhizospheric microorganisms in lieu of their pivotal role in plant's sustainability. This experiment aims to study the diversity of the culturable phylloplane bacteria of Jatropha curcas and evaluate their growth-promoting activities towards maize seedling vigor. Heterotrophic bacteria were isolated from the phylloplane of J. curcas and their 16S rRNA genes were sequenced. Sequences of the 16S rRNA gene were very similar to those of species belonging to the classes Bacillales (50%), Gammaproteobacteria (21.8%), Betaproteobacteria (15.6%), and Alphaproteobacteria (12.5%). The phylloplane bacteria preferred to utilize alcohol rather than monosaccharides and polysaccharides as a carbon source. Isolates exhibited ACC (1-aminocyclopropane-1-carboxylic acid) deaminase, phosphatase, potassium solubilization, and indole acetic acid (IAA) production activities. The phosphate-solubilizing capacity (mg of PO 4 solubilized by 10 8 cells) varied from 0.04 to 0.21. The IAA production potential (μg IAA produced by 10 8 cells in 48 h) of the isolates varied from 0.41 to 9.29. Inoculation of the isolates to maize seed significantly increased shoot and root lengths of maize seedlings. A linear regression model of the plant-growth-promoting activities significantly correlated (p < 0.01) with the growth parameters. Similarly, a correspondence analysis categorized ACC deaminase and IAA production as the major factors contributing 41% and 13.8% variation, respectively, to the growth of maize seedlings.

  14. Diversity of metabolic syndrome criteria in association with cardiovascular diseases--a family medicine-based investigation.

    Science.gov (United States)

    Ivezić-Lalić, Dragica; Bergman Marković, Biserka; Kranjčević, Ksenija; Kern, Josipa; Vrdoljak, Davorka; Vučak, Jasna

    2013-07-12

    This study compared the association between the 3 definitions of metabolic syndrome (MetS) suggested by the World Health Organization (WHO), National Cholesterol Education Programme (NCEP ATP III), and International Diabetes Federation (IDF), and the risk of cardiovascular diseases (CVD) and shows the prevalence and characteristics of persons with MetS in continental vs. coastal regions and rural vs. urban residence in Croatia. A prospective multicenter study was conducted on 3245 participants≥40 years, who visited general practices from May to July 2008 for any reason. This was a cross-sectional study of the Cardiovascular Risk and Intervention Study in Croatia-family medicine project (ISRCTN31857696). All analyzed MetS definitions showed an association with CVD, but the strongest was shown by NCEP ATP III; coronary disease OR 2.48 (95% CI 1.80-3.82), cerebrovascular disease OR 2.14 (1.19-3.86), and peripheral artery disease OR 1.55 (1.04-2.32), especially for age and male sex. According to the NCEP ATP III (IDF), the prevalence was 38.7% (45.9%) [15.9% (18.6%) in men, and 22.7% (27.3%) in women, and 28.4% (33.9%) in the continental region, 10.2% (10.9%) in the coastal region, 26.2% (31.5%) in urban areas, and 12.4% (14.4%) in rural areas. Older age, male sex, and residence in the continental area were positively associated with MetS diagnosis according to NCEP ATP III, and current smoking and Mediterranean diet adherence have protective effects. The NCEP ATP III definition seems to provide the strongest association with CVD and should therefore be preferred for use in this population.

  15. 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.

  16. Physiologically anaerobic microorganisms of the deep subsurface

    International Nuclear Information System (INIS)

    Stevens, S.E. Jr.; Chung, K.T.

    1993-10-01

    Anaerobic bacteria were isolated from deep subsurface sediment samples taken at study sites in Idaho (INEL) and Washington (HR) by culturing on dilute and concentrated medium. Morphologically distinct colonies were purified, and their responses to 21 selected physiological tests were determined. Although the number of isolates was small (18 INEL, 27 HR) some general patterns could be determined. Most strains could utilize all the carbon sources, however the glycerol and melizitose utilization was positive for 50% or less of the HR isolates. Catalase activity (27.78% at INEL, 74.07% at HR) and tryptophan metabolism (11.12% at INEL, 40.74% at HR) were significantly different between the two study sites. MPN and viable counts indicate that sediments near the water table yield the greatest numbers of anaerobes. Deeper sediments also appear to be more selective with the greatest number of viable counts on low-nutrient mediums. Likewise, only strictly obligate anaerobes were found in the deepest sediment samples. Selective media indicated the presence of methanogens, acetogens, and sulfate reducers at only the HR site

  17. Intrinsic Anaerobic Bioremediation of Hydrocarbons in Contaminated Subsurface Plumes and Marine Sediments

    Science.gov (United States)

    Nanny, M. A.; Nanny, M. A.; Suflita, J. M.; Suflita, J. M.; Davidova, I.; Kropp, K.; Caldwell, M.; Philp, R.; Gieg, L.; Rios-Hernandez, L. A.

    2001-05-01

    petroleum production plant, MS profiles consistent with the addition products of methylcycloalkenes were observed. This work helps attests to: 1) the extrapolatability of laboratory results to the field, 2) the unifying metabolic features for the anaerobic destruction of diverse types of hydrocarbons, and 3) how this information can be used to assess the intrinsic bioremediation processes in petroleum-contaminated environments.

  18. Anaerobic azo dye reduction

    OpenAIRE

    Zee, van der, F.P.

    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 dye...

  19. Effects of photochemical Transformations of Dissolved Organic Matter on Bacterial Metabolism and Diversity in Three Contrasting Coastal Sites in the Northwestern Mediterranean Sea during Summer

    International Nuclear Information System (INIS)

    Abboudi, M.

    2010-01-01

    The effects of photo transformation of dissolved organic matter (DOM) on bacterial growth, production, respiration, growth efficiency, and diversity were investigated during summer in two lagoons and one oligo trophic coastal water samples from the Northwestern Mediterranean Sea, differing widely in DOM and chromophoric DOM concentrations. Exposure of 0.2μm filtered waters to full sun radiation for 1 d resulted in small changes in optical properties and concentrations of DOM, and no changes in nitrate, nitrite, and phosphate concentrations. After exposure to sunlight or dark (control) treatments, the water samples were inoculated with the original bacterial com community. Photo transformation of DOM had contrasting effects on bacterial production and respiration, depending on the water's origin, resulting in an increase of bacterial growth efficiency for the oligo trophic coastal water sample (120%) and a decrease for the lagoon waters (20 to 40%) relative to that observed in dark treatments. We also observed that bacterial growth on DOM irradiated by full sun resulted in changes in community structure of total and metabolically active bacterial cells for the three locations studied when compared to the bacteria growing on unirradiated DOM, and that changes were mainly caused by photo transformation of DOM by UV radiation for the eutrophic lagoon and the oligo trophic coastal water and by photosynthetically active radiation (PAR) for the meso eutrophic lagoon. These initial results indicate that photo transformation of DOM significantly alters both bacterial metabolism and community structure in surface water for a variety of coastal ecosystems in the Mediterranean Sea. Further studies will be necessary to elucidate a more detailed appreciation of potential temporal and spatial variations of the effects measured. (author)

  20. Ability of industrial anaerobic ecosystems to produce methane from ethanol in psychrophilic, mesophilic and thermophilic conditions

    International Nuclear Information System (INIS)

    Mabala, Jojo Charlie

    2012-01-01

    The process of anaerobic degradation of organic matter is a natural phenomenon widespread in many ecosystems (eg, marshes, lakes, rice fields, digestive systems of animals and humans). A high microbial diversity is maintained during this process, reflecting a diversity of metabolic pathways involved. When complete, the anaerobic digestion results in the formation of biogas (mixture of methane and carbon dioxide). In terms of biotechnology, anaerobic treatment of organic pollution reduces the volume of waste and generates energy as methane recoverable in several forms (electricity, heat, natural gas, biofuels). Industrial digesters are mostly operated at 35 deg. C or 55 deg. C which requires exogenous energy. The objective of the thesis is to study the adaptability of ecosystems sourced from anaerobic industrial scale reactors treating different range of wastes from different processes to convert ethanol into biogas at various temperatures. The first phase of the study was to adapt, in laboratory reactors ecosystems to their original temperature with a readily biodegradable substrate (ethanol). Then, the performances of microbial communities (the maximum methanogenic potential and degradation kinetics) were estimated on a temperature gradient from 5 deg. C to 55 deg. C in batch reactors. The adaptation phase of the ecosystems in lab-scale reactors showed that the biogas averaged theoretical production and this production was followed by a decrease in reaction time with successive addition of the substrate. In addition, the kinetics of the biogas obtained varied greatly from one ecosystem to another. Molecular fingerprinting profiles (CE-SSCP) of bacterial and archaeal communities were performed at the beginning and at the end of conditioning. These community profiles were compared with each other by principal component analysis (PCA). Bacterial populations that ensured efficient performance were different from those that ensured a good adaptability. In addition, the

  1. Species diversity and metabolic impact of the microbiota are low in spontaneously acidified Belgian sausages with an added starter culture of Staphylococcus carnosus.

    Science.gov (United States)

    Janssens, M; Myter, N; De Vuyst, L; Leroy, F

    2012-04-01

    Quality of fermented sausages is affected by acidifying lactic acid bacteria (LAB) and colour- and flavour-promoting coagulase-negative staphylococci (CNS), whether or not used as starter culture. Artisan fermented sausages are often perceived as superior to industrial variants, partially because of the specific microbiota due to spontaneous acidification, which may be considered as an artisan characteristic. Therefore, two kinds of spontaneously acidified Belgian sausages were prepared (Belgian-type salami and Boulogne sausage), but with addition of a Staphylococcus carnosus culture. The Belgian-type salami was made from pork and beef, whereas the Boulogne sausage contained pork and horse meat. In all cases, Lactobacillus sakei was the dominant LAB species present on the raw materials and during fermentation, whereas enterococci remained present in the background. Enterobacteriaceae vanished after fermentation. The CNS species diversity on the raw materials was large and differed between the pork, beef, and horse meat. Nevertheless, this species diversity was annihilated during fermentation by the added S. carnosus culture. The volatiles fraction was mainly composed of aldehydes that originated from lipid oxidation and spices-derived compounds. Aromatic compounds that are typically associated to CNS activity, such as end-products from the metabolism of branched-chain amino acids, were not present in the Belgian-type salami and only marginally present in the Boulogne sausage. In conclusion, spontaneous acidification of Belgian-type fermented sausages leads to dominance of L. sakei and is no guarantee for bacterial contribution to the aroma profile when S. carnosus is added as a starter culture. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Applicability of generic assays based on liquid chromatography–electrospray mass spectrometry to study in vitro metabolism of 55 structurally diverse compounds

    Directory of Open Access Journals (Sweden)

    Timo Rousu

    2010-08-01

    Full Text Available Liquid chromatography-mass spectrometry (LC/MS with generic gradient elution for a large number of chemically different compounds is a common approach in drug development, used to acquire a large amount of data in a short time frame for drug candidates. The analysis with non-optimised parameters however may lead to a poor method performance for many compounds, and contains a risk of losing important information. Here, generic electrospray-time-of-flight (ESI-TOF MS methods in various pH conditions were tested for 55 chemically diverse compounds (10 acids, 25 bases, 17 neutrals and 3 amphoterics, aiming to find best analytical conditions for each compound, for studies of in vitro metabolic properties in liver preparations. The effect of eluent pH and elution gradient strength on chromatographic performance and electrospray MS ionisation efficiency were examined for each compound. The data are evaluated how well the best generic approach could cover the analysis of test compounds and how many compounds would still need completely different analytical conditions after that. Aqueous mobile phase consisting of 0.05% acetic acid and 5 mM ammonium acetate (pH 4.4 showed the best general suitability for the analyses, showing adequate performance for metabolite profiling for 41 out of 55 compounds either in positive or negative ion mode. In positive ion mode, the main limitation of performance in various pH conditions was generally not the lack of ionisation, but rather the poor chromatographic performance (inadequate retention or poor peak shape, suggesting that more emphasis should be put in finding conditions providing best chromatographic performance, rather than highest ionisation properties. However, a single generic approach for a large number of different compounds is not likely to produce good results for all compounds. Preferably, at least two or three different conditions are needed for the coverage of a larger number of structurally diverse

  3. Biogeochemistry of anaerobic crude oil biodegradation

    Science.gov (United States)

    Head, Ian; Gray, Neil; Aitken, Caroline; Sherry, Angela; Jones, Martin; Larter, Stephen

    2010-05-01

    Anaerobic degradation of crude oil and petroleum hydrocarbons is widely recognized as a globally significant process both in the formation of the world's vast heavy oil deposits and for the dissipation of hydrocarbon pollution in anoxic contaminated environments. Comparative analysis of crude oil biodegradation under methanogenic and sulfate-reducing conditions has revealed differences not only in the patterns of compound class removal but also in the microbial communities responsible. Under methanogenic conditions syntrophic associations dominated by bacteria from the Syntropheaceae are prevalent and these are likely key players in the initial anaerobic degradation of crude oil alkanes to intermediates such as hydrogen and acetate. Syntrophic acetate oxidation plays an important role in these systems and often results in methanogenesis dominated by CO2 reduction by members of the Methanomicrobiales. By contrast the bacterial communities from sulfate-reducing crude oil-degrading systems were more diverse and no single taxon dominated the oil-degrading sulfate-reducing systems. All five proteobacterial subdivisions were represented with Delta- and Gammaproteobacteria being detected most consistently. In sediments which were pasteurized hydrocarbon degradation continued at a relatively low rate. Nevertheless, alkylsuccinates characteristic of anaerobic hydrocarbon degradation accumulated to high concentrations. This suggested that the sediments harbour heat resistant, possibly spore-forming alkane degrading sulfate-reducers. This is particularly interesting since it has been proposed recently, that spore-forming sulfate-reducing bacteria found in cold arctic sediments may have originated from seepage of geofluids from deep subsurface hydrocarbon reservoirs.

  4. New perspectives in anaerobic digestion

    DEFF Research Database (Denmark)

    van Lier, J.B.; Tilche, A.; Ahring, Birgitte Kiær

    2001-01-01

    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...... 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...

  5. [Anaerobic bacteria isolated from patients with suspected anaerobic infections].

    Science.gov (United States)

    Ercis, Serpil; Tunçkanat, Ferda; Hasçelik, Gülşen

    2005-10-01

    The study involved 394 clinical samples sent to the Clinical Microbiology Laboratory of Hacettepe University Adult Hospital between January 1997 and May 2004 for anaerobic cultivation. Since multiple cultures from the same clinical samples of the same patient were excluded, the study was carried on 367 samples. The anaerobic cultures were performed in anaerobic jar using AnaeroGen kits (Oxoid, Basingstoke, U.K.) or GENbox (bioMérieux, Lyon, France). The isolates were identified by both classical methods and "BBL Crystal System" (Becton Dickinson, U.S.A.). While no growth was detected in 120 (32.7%) of the clinical samples studied, in 144 samples (39.2%) only aerobes, in 28 (7.6%) only anaerobes and in 75 (20.5%) of the samples both aerobes and anaerobes were isolated. The number of the anaerobic isolates was 217 from 103 samples with anaerobic growth. Of these 103 samples 15 showed single bacterial growth whereas in 88 samples multiple bacterial isolates were detected. Anaerobic isolates consisted of 92 Gram negative bacilli (Bacteroides spp. 50, Prevotella spp. 14, Porphyromonas spp. 10, Fusobacterium spp. 7, Tisierella spp. 2, unidentified 9), 57 Gram positive bacilli (Clostridium spp.17, Propionibacterium spp. 16, Lactobacillus spp. 8, Actinomyces spp. 5, Eubacterium spp. 2, Bifidobacterium adolescentis 1, Mobiluncus mulieris 1, unidentified nonspore forming rods 7), 61 Gram positive cocci (anaerobic cocci 44, microaerophilic cocci 17), and 7 Gram negative cocci (Veillonella spp.). In conclusion, in the samples studied with prediagnosis of anaerobic infection, Bacteroides spp. (23%) were the most common bacteria followed by anaerobic Gram positive cocci (20.3%) and Clostridium spp (7.8%).

  6. Systematization of the protein sequence diversity in enzymes related to secondary metabolic pathways in plants, in the context of big data biology inspired by the KNApSAcK motorcycle database.

    Science.gov (United States)

    Ikeda, Shun; Abe, Takashi; Nakamura, Yukiko; Kibinge, Nelson; Hirai Morita, Aki; Nakatani, Atsushi; Ono, Naoaki; Ikemura, Toshimichi; Nakamura, Kensuke; Altaf-Ul-Amin, Md; Kanaya, Shigehiko

    2013-05-01

    Biology is increasingly becoming a data-intensive science with the recent progress of the omics fields, e.g. genomics, transcriptomics, proteomics and metabolomics. The species-metabolite relationship database, KNApSAcK Core, has been widely utilized and cited in metabolomics research, and chronological analysis of that research work has helped to reveal recent trends in metabolomics research. To meet the needs of these trends, the KNApSAcK database has been extended by incorporating a secondary metabolic pathway database called Motorcycle DB. We examined the enzyme sequence diversity related to secondary metabolism by means of batch-learning self-organizing maps (BL-SOMs). Initially, we constructed a map by using a big data matrix consisting of the frequencies of all possible dipeptides in the protein sequence segments of plants and bacteria. The enzyme sequence diversity of the secondary metabolic pathways was examined by identifying clusters of segments associated with certain enzyme groups in the resulting map. The extent of diversity of 15 secondary metabolic enzyme groups is discussed. Data-intensive approaches such as BL-SOM applied to big data matrices are needed for systematizing protein sequences. Handling big data has become an inevitable part of biology.

  7. Anaerobic and aerobic transformation of TNT

    Energy Technology Data Exchange (ETDEWEB)

    Kulpa, C.F. [Univ. of Notre Dame, IN (United States). Dept. of Biological Sciences; Boopathy, R.; Manning, J. [Argonne National Lab., IL (United States). Environmental Research Div.

    1996-12-31

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

  8. Engineering of the redox imbalance of Fusarium oxysporum enables anaerobic growth on xylose

    DEFF Research Database (Denmark)

    Panagiotou, Gianni; Christakopoulos, Paul; Grotkjær, Thomas

    2006-01-01

    Dissimilatory nitrate reduction metabolism, of the natural xylose-fermenting fungus Fusarium oxysporum, was used as a strategy to achieve anaerobic growth and ethanol production from xylose. Beneficial alterations of the redox fluxes and thereby of the xylose metabolism were obtained by taking ad...

  9. New perspectives in anaerobic digestion.

    NARCIS (Netherlands)

    Lier, van J.B.; Tilche, A.; Ahring, B.K.; Macarie, H.; Moletta, R.; Dohanyos, M.; Hulshoff Pol, L.W.; Lens, P.N.L.; Verstraete, W.

    2001-01-01

    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

  10. 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.

  11. 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

  12. Pyruvate Kinase Triggers a Metabolic Feedback Loop that Controls Redox Metabolism in Respiring Cells

    NARCIS (Netherlands)

    Grüning, N.M.; Rinnerthaler, M.; Bluemlein, K.; Mulleder, M.; Wamelink, M.M.C.; Lehrach, H.; Jakobs, C.A.J.M.; Breitenbach, M.; Ralser, M.

    2011-01-01

    In proliferating cells, a transition from aerobic to anaerobic metabolism is known as the Warburg effect, whose reversal inhibits cancer cell proliferation. Studying its regulator pyruvate kinase (PYK) in yeast, we discovered that central metabolism is self-adapting to synchronize redox metabolism

  13. Anaerobic respiration of Escherichia coli in the mouse intestine.

    Science.gov (United States)

    Jones, Shari A; Gibson, Terri; Maltby, Rosalie C; Chowdhury, Fatema Z; Stewart, Valley; Cohen, Paul S; Conway, Tyrrell

    2011-10-01

    The intestine is inhabited by a large microbial community consisting primarily of anaerobes and, to a lesser extent, facultative anaerobes, such as Escherichia coli, which we have shown requires aerobic respiration to compete successfully in the mouse intestine (S. A. Jones et al., Infect. Immun. 75:4891-4899, 2007). If facultative anaerobes efficiently lower oxygen availability in the intestine, then their sustained growth must also depend on anaerobic metabolism. In support of this idea, mutants lacking nitrate reductase or fumarate reductase have extreme colonization defects. Here, we further explore the role of anaerobic respiration in colonization using the streptomycin-treated mouse model. We found that respiratory electron flow is primarily via the naphthoquinones, which pass electrons to cytochrome bd oxidase and the anaerobic terminal reductases. We found that E. coli uses nitrate and fumarate in the intestine, but not nitrite, dimethyl sulfoxide, or trimethylamine N-oxide. Competitive colonizations revealed that cytochrome bd oxidase is more advantageous than nitrate reductase or fumarate reductase. Strains lacking nitrate reductase outcompeted fumarate reductase mutants once the nitrate concentration in cecal mucus reached submillimolar levels, indicating that fumarate is the more important anaerobic electron acceptor in the intestine because nitrate is limiting. Since nitrate is highest in the absence of E. coli, we conclude that E. coli is the only bacterium in the streptomycin-treated mouse large intestine that respires nitrate. Lastly, we demonstrated that a mutant lacking the NarXL regulator (activator of the NarG system), but not a mutant lacking the NarP-NarQ regulator, has a colonization defect, consistent with the advantage provided by NarG. The emerging picture is one in which gene regulation is tuned to balance expression of the terminal reductases that E. coli uses to maximize its competitiveness and achieve the highest possible population in

  14. Selected Topics in Anaerobic Bacteriology.

    Science.gov (United States)

    Church, Deirdre L

    2016-08-01

    Alteration in the host microbiome at skin and mucosal surfaces plays a role in the function of the immune system, and may predispose immunocompromised patients to infection. Because obligate anaerobes are the predominant type of bacteria present in humans at skin and mucosal surfaces, immunocompromised patients are at increased risk for serious invasive infection due to anaerobes. Laboratory approaches to the diagnosis of anaerobe infections that occur due to pyogenic, polymicrobial, or toxin-producing organisms are described. The clinical interpretation and limitations of anaerobe recovery from specimens, anaerobe-identification procedures, and antibiotic-susceptibility testing are outlined. Bacteriotherapy following analysis of disruption of the host microbiome has been effective for treatment of refractory or recurrent Clostridium difficile infection, and may become feasible for other conditions in the future.

  15. Improved anaerobic biodegradation of biosolids by the addition of food waste as a co-substrate

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H.-W.; Han, S.-K.; Song, Y.-C.; Baek, B.-C.; Yoo, K.-S.; Lee, J.-J.; Shin, H.-S.

    2003-07-01

    The temperature phased anaerobic digestion (TPAD) process was applied to increase the performance of anaerobic treatment of biosolids. Previously obtained results indicate that this system showed the advantages of thermophilic and mesophilic anaerobic digestion process. By comparing the performance of each reactor of the system, it was illustrated that the main stage of methane production was the thermophilic reactor which has faster microbial metabolism. However, the result revealed that substrate characteristics of low VS/TS limited the system performance. Therefore, to evaluate the effect of food waste as a co-substrate for improving anaerobic biodegradability, biochemical methane potential (BMP) tests were conducted in thermophilic conditions with biomass of thermophilic reactor. It was confirmed that the co-digestion of sewage sludge mixed with food waste had a distinct improvement on biodegradability. The most significant advantages were the preferable environment provided by food waste for the growth and activity of anaerobes and the mutual assistance between biosolids and food waste. (author)

  16. Amixicile, a novel strategy for targeting oral anaerobic pathogens.

    Science.gov (United States)

    Hutcherson, Justin A; Sinclair, Kathryn M; Belvin, Benjamin R; Gui, Qin; Hoffman, Paul S; Lewis, Janina P

    2017-09-05

    The oral microflora is composed of both health-promoting as well as disease-initiating bacteria. Many of the disease-initiating bacteria are anaerobic and include organisms such as Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, and Tannerella forsythia. Here we investigated a novel therapeutic, amixicile, that targets pyruvate:ferredoxin oxidoreductase (PFOR), a major metabolic enzyme involved in energy generation through oxidative decarboxylation of pyruvate. PFOR is present in these anaerobic pathogenic bacteria and thus we hypothesized that amixicile would effectively inhibit their growth. In general, PFOR is present in all obligate anaerobic bacteria, while oral commensal aerobes, including aerotolerant ones, such as Streptococcus gordonii, use pyruvate dehydrogenase to decarboxylate pyruvate. Accordingly, we observed that growth of the PFOR-containing anaerobic periodontal pathogens, grown in both monospecies as well as multispecies broth cultures was inhibited in a dose-dependent manner while that of S. gordonii was unaffected. Furthermore, we also show that amixicile is effective against these pathogens grown as monospecies and multispecies biofilms. Finally, amixicile is the first selective therapeutic agent active against bacteria internalized by host cells. Together, the results show that amixicile is an effective inhibitor of oral anaerobic bacteria and as such, is a good candidate for treatment of periodontal diseases.

  17. Physiological and functional diversity of phenol degraders isolated from phenol-grown aerobic granules: Phenol degradation kinetics and trichloroethylene co-metabolic activities.

    Science.gov (United States)

    Zhang, Yi; Tay, Joo Hwa

    2016-03-15

    Aerobic granule is a novel form of microbial aggregate capable of degrading toxic and recalcitrant substances. Aerobic granules have been formed on phenol as the growth substrate, and used to co-metabolically degrade trichloroethylene (TCE), a synthetic solvent not supporting aerobic microbial growth. Granule formation process, rate limiting factors and the comprehensive toxic effects of phenol and TCE had been systematically studied. To further explore their potential at the level of microbial population and functions, phenol degraders were isolated and purified from mature granules in this study. Phenol and TCE degradation kinetics of 15 strains were determined, together with their TCE transformation capacities and other physiological characteristics. Isolation in the presence of phenol and TCE exerted stress on microbial populations, but the procedure was able to preserve their diversity. Wide variation was found with the isolates' kinetic behaviors, with the parameters often spanning 3 orders of magnitude. Haldane kinetics described phenol degradation well, and the isolates exhibited actual maximum phenol-dependent oxygen utilization rates of 9-449 mg DO g DW(-1) h(-1), in phenol concentration range of 4.8-406 mg L(-1). Both Michaelis-Menten and Haldane types were observed for TCE transformation, with the actual maximum rate of 1.04-21.1 mg TCE g DW(-1) h(-1) occurring between TCE concentrations of 0.42-4.90 mg L(-1). The TCE transformation capacities and growth yields on phenol ranged from 20-115 mg TCE g DW(-1) and 0.46-1.22 g DW g phenol(-1), respectively, resulting in TCE transformation yields of 10-70 mg TCE g phenol(-1). Contact angles of the isolates were between 34° and 82°, suggesting both hydrophobic and hydrophilic cell surface. The diversity in the isolates is a great advantage, as it enables granules to be versatile and adaptive under different operational conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Anaerobic bacteria colonizing the lower airways in lung cancer patients.

    Science.gov (United States)

    Rybojad, Pawel; Los, Renata; Sawicki, Marek; Tabarkiewicz, Jacek; Malm, Anna

    2011-01-01

    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.

  19. 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

  20. Quantification of patterns of regional cardiac metabolism

    International Nuclear Information System (INIS)

    Lear, J.L.; Ackermann, R.F.

    1990-01-01

    To quantitatively map and compare patterns of regional cardiac metabolism with greater spatial resolution than is possible with positron emission tomography (PET), the authors developed autoradiographic techniques for use with combinations of radiolabeled fluorodeoxyglucose (FDG), glucose (GLU), and acetate (ACE) and applied the techniques to normal rats. Kinetic models were developed to compare GLU-based oxidative glucose metabolism with FDG-based total glucose metabolism (oxidative plus anaerobic) and to compare ACE-based overall oxidative metabolism with FDG-based total glucose metabolism. GLU-based metabolism generally paralleled FDG-based metabolism, but divergence occurred in certain structures such as the papillary muscles, where FDG-based metabolism was much greater. ACE-based metabolism also generally paralleled FDG-based metabolism, but again, the papillary muscles had relatively greater FDG-based metabolism. These discrepancies between FDG-based metabolism and GLU- or ACE-based metabolism suggest the presence of high levels of anaerobic glycolysis. Thus, the study indicates that anaerobic glycolysis, in addition to occurring in ischemic or stunned myocardium (as has been shown in recent PET studies), occurs normally in specific cardiac regions, despite the presence of abundant oxygen

  1. Anaerobes as Sources of Bioactive Compounds and Health Promoting Tools.

    Science.gov (United States)

    Mamo, Gashaw

    Aerobic microorganisms have been sources of medicinal agents for several decades and an impressive variety of drugs have been isolated from their cultures, studied and formulated to treat or prevent diseases. On the other hand, anaerobes, which are believed to be the oldest life forms on earth and evolved remarkably diverse physiological functions, have largely been neglected as sources of bioactive compounds. However, results obtained from the limited research done so far show that anaerobes are capable of producing a range of interesting bioactive compounds that can promote human health. In fact, some of these bioactive compounds are found to be novel in their structure and/or mode of action.Anaerobes play health-promoting roles through their bioactive products as well as application of whole cells. The bioactive compounds produced by these microorganisms include antimicrobial agents and substances such as immunomodulators and vitamins. Bacteriocins produced by anaerobes have been in use as preservatives for about 40 years. Because these substances are effective at low concentrations, encounter relatively less resistance from bacteria and are safe to use, there is a growing interest in these antimicrobial agents. Moreover, several antibiotics have been reported from the cultures of anaerobes. Closthioamide and andrimid produced by Clostridium cellulolyticum and Pantoea agglomerans, respectively, are examples of novel antibiotics of anaerobe origin. The discovery of such novel bioactive compounds is expected to encourage further studies which can potentially lead to tapping of the antibiotic production potential of this fascinating group of microorganisms.Anaerobes are widely used in preparation of fermented foods and beverages. During the fermentation processes, these organisms produce a number of bioactive compounds including anticancer, antihypertensive and antioxidant substances. The well-known health promoting effect of fermented food is mostly due to these

  2. Isolation and some characteristics of anaerobic oxalate-degrading bacteria from the rumen.

    OpenAIRE

    Dawson, K A; Allison, M J; Hartman, P A

    1980-01-01

    Obligately anaerobic oxalate-degrading bacteria were isolated from an enriched population of rumen bacteria in an oxalate-containing medium that had been depleted of other readily metabolized substrates. These organisms, which are the first reported anaerobic oxalate degraders isolated from the rumen, were gram negative, nonmotile rods. They grew in a medium containing sodium oxalate, yeast extract, cysteine, and minerals. The only substrate that supported growth was oxalate. Growth was direc...

  3. Groundbreaking technology: in-situ anaerobic bioremediation for treatment of contaminated soil and groundwater

    International Nuclear Information System (INIS)

    Fernandes, K.A.

    2002-01-01

    Anaerobic in-situ bioremediation is a technique often used to cleanse contaminated soil and groundwater. 'Anaerobic in-situ bioremediation' is a phrase with distinct terms all having relevance in the application of this technique. Anaerobic implies the absence of dissolved oxygen, while 'in-situ' simply means that the environmental cleansing occurs with out removing, displacing, or significantly disturbing the specimen or surrounding area. 'Bioremediation' is a term used to describe the biological use of microbes or plants to detoxify the environment. In order to properly implement this complex process, one must have an understanding of microbiology, biochemistry, genetics, metabolic processes, and structure and function of natural microbial communities. (author)

  4. Metabolic imaging using SPECT

    International Nuclear Information System (INIS)

    Taki, Junichi; Matsunari, Ichiro

    2007-01-01

    In normal condition, the heart obtains more than two-thirds of its energy from the oxidative metabolism of long chain fatty acids, although a wide variety of substrates such as glucose, lactate, ketone bodies and amino acids are also utilised. In ischaemic myocardium, on the other hand, oxidative metabolism of free fatty acid is suppressed and anaerobic glucose metabolism plays a major role in residual oxidative metabolism. Therefore, metabolic imaging can be an important technique for the assessment of various cardiac diseases and conditions. In SPECT, several iodinated fatty acid traces have been introduced and studied. Of these, 123 I-labelled 15-(p-iodophenyl)3-R, S-methylpentadecanoic acid (BMIPP) has been the most commonly used tracer in clinical studies, especially in some of the European countries and Japan. In this review article, several fatty acid tracers for SPECT are characterised, and the mechanism of uptake and clinical utility of BMIPP are discussed in detail. (orig.)

  5. Geochemical constraints on sources of metabolic energy for chemolithoautotrophy in ultramafic-hosted deep-sea hydrothermal systems.

    Science.gov (United States)

    McCollom, Thomas M

    2007-12-01

    Numerical models are employed to investigate sources of chemical energy for autotrophic microbial metabolism that develop during mixing of oxidized seawater with strongly reduced fluids discharged from ultramafic-hosted hydrothermal systems on the seafloor. Hydrothermal fluids in these systems are highly enriched in H(2) and CH(4) as a result of alteration of ultramafic rocks (serpentinization) in the subsurface. Based on the availability of chemical energy sources, inferences are made about the likely metabolic diversity, relative abundance, and spatial distribution of microorganisms within ultramafic-hosted systems. Metabolic reactions involving H(2) and CH(4), particularly hydrogen oxidation, methanotrophy, sulfate reduction, and methanogenesis, represent the predominant sources of chemical energy during fluid mixing. Owing to chemical gradients that develop from fluid mixing, aerobic metabolisms are likely to predominate in low-temperature environments (energy per kilogram of hydrothermal fluid, while anaerobic metabolic reactions can supply about 1 kJ, which is sufficient to support a maximum of approximately 120 mg (dry weight) of primary biomass production by aerobic organisms and approximately 20-30 mg biomass by anaerobes. The results indicate that ultramafic-hosted systems are capable of supplying about twice as much chemical energy as analogous deep-sea hydrothermal systems hosted in basaltic rocks.

  6. Isolation of a human intestinal anaerobe, Bifidobacterium sp. strain SEN, capable of hydrolyzing sennosides to sennidins.

    OpenAIRE

    Akao, T; Che, Q M; Kobashi, K; Yang, L; Hattori, M; Namba, T

    1994-01-01

    A strictly anaerobic bacterium capable of metabolizing sennosides was isolated from human feces and identified as Bifidobacterium sp., named strain SEN. The bacterium hydrolyzed sennosides A and B to sennidins A and B via sennidin A and B 8-monoglucosides, respectively. Among nine species of Bifidobacterium having beta-glucosidase activity, only Bifidobacterium dentium and B. adolescentis metabolized sennoside B to sennidin B, suggesting that the sennoside-metabolizing bacteria produce a nove...

  7. Implementing Livestock Anaerobic Digestion Projects

    Science.gov (United States)

    Page provides information to help make an informed decision about installing an anaerobic digester. Is it a good match for a farm’s organic waste, project financing, development guidelines and permit requirements?

  8. Anaerobic toxicity of cationic silver nanoparticles

    International Nuclear Information System (INIS)

    Gitipour, Alireza; Thiel, Stephen W.; Scheckel, Kirk G.; Tolaymat, Thabet

    2016-01-01

    The microbial toxicity of silver nanoparticles (AgNPs) stabilized with different capping agents was compared to that of Ag"+ under anaerobic conditions. Three AgNPs were investigated: (1) negatively charged citrate-coated AgNPs (citrate-AgNPs), (2) minimally charged polyvinylpyrrolidone coated AgNPs (PVP-AgNPs) and (3) positively charged branched polyethyleneimine coated AgNPs (BPEI-AgNPs). The AgNPs investigated in this experiment were similar in size (10–15 nm), spherical in shape, but varied in surface charge which ranged from highly negative to highly positive. While, at AgNPs concentrations lower than 5 mg L"−"1, the anaerobic decomposition process was not influenced by the presence of the nanoparticles, there was an observed impact on the diversity of the microbial community. At elevated concentrations (100 mg L"−"1 as silver), only the cationic BPEI-AgNPs demonstrated toxicity similar in magnitude to that of Ag"+. Both citrate and PVP-AgNPs did not exhibit toxicity at the 100 mg L"−"1 as measured by biogas evolution. These findings further indicate the varying modes of action for nanoparticle toxicity and represent one of the few studies that evaluate end-of-life management concerns with regards to the increasing use of nanomaterials in our everyday life. These findings also highlight some of the concerns with a one size fits all approach to the evaluation of environmental health and safety concerns associated with the use of nanoparticles. - Highlights: • At concentrations -1 the anaerobic decomposition process was not impacted. • An impact on the microbial community at concentrations -1 were observed. • At high concentrations (100 mg L"−"1), the cationic BPEI-AgNPs demonstrated toxicity. • Toxicity was demonstrated without the presence of oxidative dissolution of silver. • A one size fits all approach for the evaluation of NPs may not be accurate.

  9. Ecophysiology of terminal carbon metabolizing bacteria in anoxic sedimentary environments

    International Nuclear Information System (INIS)

    Phelps, T.J.

    1985-01-01

    Chemical, radiotracer, and microbiological experiments were used to understand the transformation of simple carbon compounds by anaerobic bacteria in diverse aquatic sediments and laboratory cultures. The mildly acidic sediments of Knack Lake (pH 6.2), displayed low rates of organic decomposition, and methane formation occurred almost exclusively from acetate. Low pH inhibited methanogenesis and organic decomposition. Fall turnover in Lake Mendota sediments was associated with dramatic changes in environmental parameters including: elevated concentrations of sulfate and carbon metabolites, increased rates of sulfate reduction, decreased levels of methanogenesis, increased ratio (by viable counts) of sulfate reducing to methanogenic bacteria, and higher 14 CO 2 / 14 C 4 + 14 CO 2 gas ratios produced during the biodegradation of 14 C-carbon substrates (e.g., acetate and methanol). Hydrogen consumption by sulfate reducers in Lake Mendota sediments and in co-cultures of Desulfovibrio vulgaris and Methanosarcina barkeri led to an alteration in the carbon and electron flow pathway resulting in increased CO 2 , sulfide production, and decreased methanogenesis. These data agreed with the environmental observations in Lake Mendota that high sulfate concentrations resulted in higher ratios of CO 2 /CH 4 produced from the degradation of organic matter. A new glycine-metabolizing acetogenic species was isolated and characterized from Knaack Lake which further extended the known diversity of anaerobic bacteria in nature

  10. High performance biological methanation in a thermophilic anaerobic trickle bed reactor.

    Science.gov (United States)

    Strübing, Dietmar; Huber, Bettina; Lebuhn, Michael; Drewes, Jörg E; Koch, Konrad

    2017-12-01

    In order to enhance energy efficiency of biological methanation of CO 2 and H 2 , this study investigated the performance of a thermophilic (55°C) anaerobic trickle bed reactor (ATBR) (58.1L) at ambient pressure. With a methane production rate of up to 15.4m 3 CH4 /(m 3 trickle bed ·d) at methane concentrations above 98%, the ATBR can easily compete with the performance of other mixed culture methanation reactors. Control of pH and nutrient supply turned out to be crucial for stable operation and was affected significantly by dilution due to metabolic water production, especially during demand-orientated operation. Considering practical applications, inoculation with digested sludge, containing a diverse biocenosis, showed high adaptive capacity due to intrinsic biological diversity. However, no macroscopic biofilm formation was observed at thermophilic conditions even after 313days of operation. The applied approach illustrates the high potential of thermophilic ATBRs as a very efficient energy conversion and storage technology. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Acetate and succinate production in amoebae, helminths, diplomonads, trichomonads and trypanosomatids: common and diverse metabolic strategies used by parasitic lower eukaryotes.

    Science.gov (United States)

    Bringaud, F; Ebikeme, C; Boshart, M

    2010-08-01

    Parasites that often grow anaerobically in their hosts have adopted a fermentative strategy relying on the production of partially oxidized end products, including lactate, glycerol, ethanol, succinate and acetate. This review focuses on recent progress in understanding acetate production in protist parasites, such as amoebae, diplomonads, trichomonads, trypanosomatids and in the metazoan parasites helminths, as well as the succinate production pathway(s) present in some of them. We also describe the unconventional organisation of the tricarboxylic acid cycle associated with the fermentative strategy adopted by the procyclic trypanosomes, which may resemble the probable structure of the primordial TCA cycle in prokaryotes.

  12. Anaerobic bacteria that dechlorinate perchloroethene.

    Science.gov (United States)

    Fathepure, B Z; Nengu, J P; Boyd, S A

    1987-01-01

    In this study, we identified specific cultures of anaerobic bacteria that dechlorinate perchlorethene (PCE). The bacteria that significantly dechlorinated PCE were strain DCB-1, an obligate anaerobe previously shown to dechlorinate chlorobenzoate, and two strains of Methanosarcina. The rate of PCE dechlorination by DCB-1 compared favorably with reported rates of trichloroethene bio-oxidation by methanotrophs. Even higher PCE dechlorination rates were achieved when DCB-1 was grown in a methanogenic consortium. PMID:3426224

  13. PENGOLAHAN LIMBAH CAIR INDUSTRI FARMASI FORMULASI DENGAN METODE ANAEROB-AEROB DAN ANAEROB-KOAGULASI

    OpenAIRE

    Farida Crisnaningtyas; Hanny Vistanty

    2016-01-01

    Studi ini membahas mengenai pengolahan limbah cair industri farmasi dalam skala laboratorium dengan menggunakan konsep anaerob-kimia-fisika dan anaerob-aerob. Proses anaerob dilakukan dengan menggunakan reaktor Upflow Anaerobic Sludge Bed reactor (UASBr) pada kisaran OLR (Organic Loading Rate) 0,5 – 2 kg COD/m3hari, yang didahului dengan proses aklimatisasi menggunakan substrat gula. Proses anaerob mampu memberikan efisiensi penurunan COD hingga 74%. Keluaran dari proses anaerob diolah lebih ...

  14. The effect of trace elements on the metabolism of methanogenic consortia

    NARCIS (Netherlands)

    Jiang, B.

    2006-01-01

    Trace metals are essential for the growth and metabolism of anaerobic microorganisms, duo to their roles in key enzymes or cofactors of metabolic pathways. The requirement of trace metals has been recognized. But, proper dosing of these metals in anaerobic treatment system as nutrient still is a

  15. Microbial diversity in methane hydrate-bearing deep marine sediments core preserved in the original pressure.

    Science.gov (United States)

    Takahashi, Y.; Hata, T.; Nishida, H.

    2017-12-01

    In normal coring of deep marine sediments, the sampled cores are exposed to the pressure of the atmosphere, which results in dissociation of gas-hydrates and might change microbial diversity. In this study, we analyzed microbial composition in methane hydrate-bearing sediment core sampled and preserved by Hybrid-PCS (Pressure Coring System). We sliced core into three layers; (i) outside layer, which were most affected by drilling fluids, (ii) middle layer, and (iii) inner layer, which were expected to be most preserved as the original state. From each layer, we directly extracted DNA, and amplified V3-V4 region of 16S rRNA gene. We determined at least 5000 of nucleotide sequences of the partial 16S rDNA from each layer by Miseq (Illumina). In the all layers, facultative anaerobes, which can grow with or without oxygen because they can metabolize energy aerobically or anaerobically, were detected as majority. However, the genera which are often detected anaerobic environment is abundant in the inner layer compared to the outside layer, indicating that condition of drilling and preservation affect the microbial composition in the deep marine sediment core. This study was conducted as a part of the activity of the Research Consortium for Methane Hydrate Resources in Japan [MH21 consortium], and supported by JOGMEC (Japan Oil, Gas and Metals National Corporation). The sample was provided by AIST (National Institute of Advanced Industrial Science and Technology).

  16. Exposure to polystyrene nanoplastic leads to inhibition of anaerobic digestion system.

    Science.gov (United States)

    Fu, Shan-Fei; Ding, Jian-Nan; Zhang, Yun; Li, Yi-Fei; Zhu, Rong; Yuan, Xian-Zheng; Zou, Hua

    2018-06-01

    In this study, impacts of nanoplastic on the pure and mixed anaerobic digestion systems were investigated. Results showed the growth and metabolism of Acetobacteroides hydrogenigenes were partly inhibited by nanoplastic existed in the pure anaerobic digestion system. The anaerobic digestion of sewage sludge was also obviously inhibited by nanoplastic existed in the mixed anaerobic digestion system. Both the methane yield and methane production rate of the mixed anaerobic digestion system showed negative correlation with the nanoplastic concentration. Compared with anaerobic digestion system without nanoplastic, methane yield and maximum daily methane yield at the nanoplastic concentration of 0.2g/L decreased for 14.4% and 40.7%, respectively. In addition, the start-up of mixed anaerobic digestion system was prolonged by addition of nanoplastic. Microbial community structure analysis indicated the microbial community structures were also affected by nanoplastic existed in the system. At the nanoplastic concentration of 0.2g/L, the relative abundances of family Cloacamonaceae, Porphyromonadaceae, Anaerolinaceae and Gracilibacteraceae decreased partly. Conversely, the relative abundances of family Anaerolinaceae, Clostridiaceae, Geobacteraceae, Dethiosulfovibrionaceae and Desulfobulbaceae improved partly. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Microbial diversity in European alpine permafrost and active layers.

    Science.gov (United States)

    Frey, Beat; Rime, Thomas; Phillips, Marcia; Stierli, Beat; Hajdas, Irka; Widmer, Franco; Hartmann, Martin

    2016-03-01

    Permafrost represents a largely understudied genetic resource. Thawing of permafrost with global warming will not only promote microbial carbon turnover with direct feedback on greenhouse gases, but also unlock an unknown microbial diversity. Pioneering metagenomic efforts have shed light on the permafrost microbiome in polar regions, but temperate mountain permafrost is largely understudied. We applied a unique experimental design coupled to high-throughput sequencing of ribosomal markers to characterize the microbiota at the long-term alpine permafrost study site 'Muot-da-Barba-Peider' in eastern Switzerland with an approximate radiocarbon age of 12 000 years. Compared to the active layers, the permafrost community was more diverse and enriched with members of the superphylum Patescibacteria (OD1, TM7, GN02 and OP11). These understudied phyla with no cultured representatives proposedly feature small streamlined genomes with reduced metabolic capabilities, adaptations to anaerobic fermentative metabolisms and potential ectosymbiotic lifestyles. The permafrost microbiota was also enriched with yeasts and lichenized fungi known to harbour various structural and functional adaptation mechanisms to survive under extreme sub-zero conditions. These data yield an unprecedented view on microbial life in temperate mountain permafrost, which is increasingly important for understanding the biological dynamics of permafrost in order to anticipate potential ecological trajectories in a warming world. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Influence of pretreatment techniques on anaerobic digestion of pulp and paper mill sludge: A review.

    Science.gov (United States)

    Veluchamy, C; Kalamdhad, Ajay S

    2017-12-01

    Pulp and paper industry is one of the most polluting, energy and water intensive industries in the world. Produced pulp and paper mill sludge (PPMS) faces a major problem for handling and its management. An anaerobic digestion has become an alternative source. This review provides a detailed summary of anaerobic digestion of PPMS - An overview of the developments and improvement opportunities. This paper explores the different pretreatment methods to enhance biogas production from the PPMS. First, the paper gives an overview of PPMS production, and then it reviews PPMS as a substrate for anaerobic digestion with or without pretreatment. Finally, it discuss the optimal condition and concentration of organic and inorganic compounds required for the anaerobic metabolic activity. Future research should focus on the combination of different pretreatment technologies, relationship between sludge composition, reactor design and its operation, and microbial community dynamics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. 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

  20. RISK FACTORS IN NEONATAL ANAEROBIC INFECTIONS

    Directory of Open Access Journals (Sweden)

    M. S. Tabib

    2008-06-01

    Full Text Available Anaerobic bacteria are well known causes of sepsis in adults but there are few studies regarding their role in neonatal sepsis. In an attempt to define the incidence of neonatal anaerobic infections a prospective study was performed during one year period. A total number of 400 neonates under sepsis study were entered this investigation. Anaerobic as well as aerobic cultures were sent. The patients were subjected to comparison in two groups: anaerobic culture positive and anaerobic culture negative and this comparison were analyzed statistically. There were 7 neonates with positive anaerobic culture and 35 neonates with positive aerobic culture. A significant statistical relationship was found between anaerobic infections and abdominal distention and pneumonia. It is recommended for those neonates with abdominal distention and pneumonia refractory to antibiotic treatment to be started on antibiotics with anaerobic coverage.

  1. Transcriptome Changes Associated with Anaerobic Growth in Yersinia intermedia (ATCC29909)

    Science.gov (United States)

    Kiley, Patricia J.; Glasner, Jeremy D.; Perna, Nicole T.

    2013-01-01

    Background The yersiniae (Enterobacteriaceae) occupy a variety of niches, including some in human and flea hosts. Metabolic adaptations of the yersiniae, which contribute to their success in these specialized environments, remain largely unknown. We report results of an investigation of the transcriptome under aerobic and anaerobic conditions for Y. intermedia, a non-pathogenic member of the genus that has been used as a research surrogate for Y. pestis. Y. intermedia shares characteristics of pathogenic yersiniae, but is not known to cause disease in humans. Oxygen restriction is an important environmental stimulus experienced by many bacteria during their life-cycles and greatly influences their survival in specific environments. How oxygen availability affects physiology in the yersiniae is of importance in their life cycles but has not been extensively characterized. Methodology/Principal Findings Tiled oligonucleotide arrays based on a draft genome sequence of Y. intermedia were used in transcript profiling experiments to identify genes that change expression in response to oxygen availability during growth in minimal media with glucose. The expression of more than 400 genes, constituting about 10% of the genome, was significantly altered due to oxygen-limitation in early log phase under these conditions. Broad functional categorization indicated that, in addition to genes involved in central metabolism, genes involved in adaptation to stress and genes likely involved with host interactions were affected by oxygen-availability. Notable among these, were genes encoding functions for motility, chemotaxis and biosynthesis of cobalamin, which were up-regulated and those for iron/heme utilization, methionine metabolism and urease, which were down-regulated. Conclusions/Significance This is the first transcriptome analysis of a non-pathogenic Yersinia spp. and one of few elucidating the global response to oxygen limitation for any of the yersiniae. Thus this study

  2. Anaerobic α-Amylase Production and Secretion with Fumarate as the Final Electron Acceptor in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Liu, Zihe; Österlund, Tobias; Hou, Jin

    2013-01-01

    In this study, we focus on production of heterologous α-amylase in the yeast Saccharomyces cerevisiae under anaerobic conditions. We compare the metabolic fluxes and transcriptional regulation under aerobic and anaerobic conditions, with the objective of identifying the final electron acceptor...... reticulum are transferred to fumarate as the final electron acceptor. This model is supported by findings that the addition of fumarate under anaerobic (but not aerobic) conditions improves cell growth, specifically in the α-amylase-producing strain, in which it is not used as a carbon source. Our results...... provide a model for the molecular mechanism of anaerobic protein secretion using fumarate as the final electron acceptor, which may allow for further engineering of yeast for improved protein secretion under anaerobic growth conditions....

  3. 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...

  4. 21 CFR 866.2120 - Anaerobic chamber.

    Science.gov (United States)

    2010-04-01

    ... 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. (a) Identification. An anaerobic chamber is a device intended for medical purposes to maintain an anaerobic (oxygen...

  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

  6. The phenomenon of granulation of anaerobic sludge

    NARCIS (Netherlands)

    Hulshoff Pol, L.

    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

  7. Microbial degradation of 4-monobrominated diphenyl ether with anaerobic sludge

    International Nuclear Information System (INIS)

    Shih, Yang-hsin; Chou, Hsi-Ling; Peng, Yu-Huei

    2012-01-01

    Highlights: ► BDE-3 was degraded with two anaerobes in different rates. ► Glucose addition augment the debromination efficiencies. ► Hydrogen gas was detected and relative microbes were identified. ► Extra-carbon source enhanced degradation partial due to H 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 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.

  8. Microbial examination of anaerobic sludge adaptation to animal slurry.

    Science.gov (United States)

    Moset, V; Cerisuelo, A; Ferrer, P; Jimenez, A; Bertolini, E; Cambra-López, M

    2014-01-01

    The objective of this study was to evaluate changes in the microbial population of anaerobic sludge digesters during the adaptation to pig slurry (PS) using quantitative real-time polymerase chain reaction (qPCR) and qualitative scanning electron microscopy (SEM). Additionally, the relationship between microbial parameters and sludge physicochemical composition and methane yield was examined. Results showed that the addition of PS to an unadapted thermophilic anaerobic digester caused an increase in volatile fatty acids (VFA) concentration, a decrease in removal efficiency and CH4 yield. Additionally, increases in total bacteria and total archaea were observed using qPCR. Scanning electron micrographs provided a general overview of the sludge's cell morphology, morphological diversity and degree of organic matter degradation. A change in microbial morphotypes from homogeneous cell morphologies to a higher morphological diversity, similar to that observed in PS, was observed with the addition of PS by SEM. Therefore, the combination of qPCR and SEM allowed expanding the knowledge about the microbial adaptation to animal slurry in thermophilic anaerobic digesters.

  9. Genome analysis of a Limnobacter sp. identified in an anaerobic methane-consuming cell consortium

    Directory of Open Access Journals (Sweden)

    Ying Chen

    2016-12-01

    Full Text Available Species of Limnobacter genus are widespread in a variety of environments, yet knowledges upon their metabolic potentials and mechanisms of environmental adaptation are limited. In this study, a cell aggregate containing Limnobacter and anaerobic methanotrophic archaea (ANME was captured from an enriched anaerobic methane oxidizing (AOM microbial community. A genomic bin of Limnobacter was obtained and analyzed, which provides the first metabolic insights into Limnobacter from an AOM environment. This Limnobacter was found to contain genes involved in the Embden-Meyerhof pathway, the citrate cycle, citronellol degradation, and transporters of various organic substances, indicating a potentially heterotrophic lifestyle. A number of genes involved in sulfur oxidization, oxidative phosphorylation and ethanol fermentation that serve both aerobic and anaerobic purposes have been found in Limnobacter. This work suggests that in the AOM environment, Limnobacter strains may live on the organic substances produced through AOM activity and subsequently may contribute to the AOM community by providing sulfate from sulfur oxidation.

  10. 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.

  11. 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.

  12. 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...

  13. Inhibition of Anaerobic Biological Treatment: A Review

    Science.gov (United States)

    Hou, Li; Ji, Dandan; Zang, Lihua

    2018-01-01

    Anaerobic digestion is a method for treating living and industrial wastewater by anaerobic degradation of organic compounds, which can produce biogas (carbon dioxide and methane mixture) and microbial biomass. And biogas as a renewable resource, can replace the use of ore fuel. In the process of anaerobic digestion, the problems of low methane yield and unstable reaction process are often encountered, which limits the widespread use of this technology. Various inhibitors are the main limiting factors for anaerobic digestion. In this paper, the main factors limiting anaerobic digestion are reviewed, and the latest research progress is introduced.

  14. Anaerobic bacteria as producers of antibiotics.

    Science.gov (United States)

    Behnken, Swantje; Hertweck, Christian

    2012-10-01

    Anaerobic bacteria are the oldest terrestrial creatures. They occur ubiquitously in soil and in the intestine of higher organisms and play a major role in human health, ecology, and industry. However, until lately no antibiotic or any other secondary metabolite has been known from anaerobes. Mining the genome sequences of Clostridium spp. has revealed a high prevalence of putative biosynthesis genes (PKS and NRPS), and only recently the first antibiotic from the anaerobic world, closthioamide, has been isolated from the cellulose degrading bacterium Clostridium cellulolyticum. The successful genetic induction of antibiotic biosynthesis in an anaerobe encourages further investigations of obligate anaerobes to tap their hidden biosynthetic potential.

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

    DEFF Research Database (Denmark)

    Lloyd, Karen; Teske, Andreas; Alperin, Marc J.

    2011-01-01

    . Anaerobic methane oxidation regulates methane emissions in marine sediments and appears to occur through a reversal of a methane-producing metabolism. We tested the assumption that ANME are obligate methanotrophs by detecting and quantifying gene transcription of ANME-1 across zones of methane oxidation...

  16. [Current clinical significance of anaerobic bacteremia].

    Science.gov (United States)

    Jirsa, Roman; Marešová, Veronika; Brož, Zdeněk

    2010-10-01

    to estimate tje current clinical significance of anaerobic bacteremia in a group of Czech hospitals. this retrospective analysis comprised 8 444 anaerobic blood cultures in patients admitted to four Czech hospitals between 2004 and 2007. in 16 patients, blood cultures yielded significant anaerobic bacteria. Thus, anaerobic bacteremia accounted for less than 2 % of clinically significant bacteremia. Four patients (18 %) died but none of the deaths could be clearly attributable to anaerobic bacteria in the bloodstream. The most common comorbidities predisposing to anaerobic bacteremia and the most frequent sources of infection were similar to those reported by other authors. The majority of anaerobic bacteremia cases were due to gram-negative bacteria, followed by Clostridium perfringens and, surprisingly, Eubacterium spp. (particularly Eubacterium lentum). anaerobic bacteremia remains rare. The comparison of our data with those by other authors suggests that (despite the reported high mortality) the actual clinical significance of anaerobic bacteremia is rather controversial and that the anaerobic bacteremia might not correspond to more serious pathogenic role of the anaerobic bacteria as the source of infection.

  17. Anaerobic toxicity of cationic silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Gitipour, Alireza; Thiel, Stephen W. [Biomedical, Chemical, and Environmental Engineering, University of Cincinnati, Cincinnati, OH (United States); Scheckel, Kirk G. [USEPA, Office of Research and Development, Cincinnati, OH (United States); Tolaymat, Thabet, E-mail: tolaymat.thabet@epa.gov [USEPA, Office of Research and Development, Cincinnati, OH (United States)

    2016-07-01

    The microbial toxicity of silver nanoparticles (AgNPs) stabilized with different capping agents was compared to that of Ag{sup +} under anaerobic conditions. Three AgNPs were investigated: (1) negatively charged citrate-coated AgNPs (citrate-AgNPs), (2) minimally charged polyvinylpyrrolidone coated AgNPs (PVP-AgNPs) and (3) positively charged branched polyethyleneimine coated AgNPs (BPEI-AgNPs). The AgNPs investigated in this experiment were similar in size (10–15 nm), spherical in shape, but varied in surface charge which ranged from highly negative to highly positive. While, at AgNPs concentrations lower than 5 mg L{sup −1}, the anaerobic decomposition process was not influenced by the presence of the nanoparticles, there was an observed impact on the diversity of the microbial community. At elevated concentrations (100 mg L{sup −1} as silver), only the cationic BPEI-AgNPs demonstrated toxicity similar in magnitude to that of Ag{sup +}. Both citrate and PVP-AgNPs did not exhibit toxicity at the 100 mg L{sup −1} as measured by biogas evolution. These findings further indicate the varying modes of action for nanoparticle toxicity and represent one of the few studies that evaluate end-of-life management concerns with regards to the increasing use of nanomaterials in our everyday life. These findings also highlight some of the concerns with a one size fits all approach to the evaluation of environmental health and safety concerns associated with the use of nanoparticles. - Highlights: • At concentrations -1 the anaerobic decomposition process was not impacted. • An impact on the microbial community at concentrations -1 were observed. • At high concentrations (100 mg L{sup −1}), the cationic BPEI-AgNPs demonstrated toxicity. • Toxicity was demonstrated without the presence of oxidative dissolution of silver. • A one size fits all approach for the evaluation of NPs may not be accurate.

  18. The utility of anaerobic blood culture in detecting facultative anaerobic bacteremia in children.

    Science.gov (United States)

    Shoji, Kensuke; Komuro, Hisako; Watanabe, Yasushi; Miyairi, Isao

    2013-08-01

    Routine anaerobic blood culture is not recommended in children because obligate anaerobic bacteremia is rare in the pediatric population. However, a number of facultative anaerobic bacteria can cause community and hospital acquired infections in children and the utility of anaerobic blood culture for detection of these organisms is still unclear. We conducted a retrospective analysis of all blood culture samples (n = 24,356) at a children's hospital in Japan from October 2009 to June 2012. Among the samples that had paired aerobic and anaerobic blood cultures, 717 samples were considered clinically significant with 418 (58%) organisms detected from both aerobic and anaerobic cultures, 167 (23%) detected only from aerobic culture and 132 (18%) detected only from anaerobic culture. While most facultative anaerobes were detectable by aerobic culture, over 25% of Enterobacteriaceae and 15% of Staphylococcus sp. were detected from anaerobic cultures bottles only, suggesting its potential role in selected settings. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Linking phylogenetic and functional diversity to nutrient spiraling in microbial mats from Lower Kane Cave (USA).

    Science.gov (United States)

    Engel, Annette Summers; Meisinger, Daniela B; Porter, Megan L; Payn, Robert A; Schmid, Michael; Stern, Libby A; Schleifer, K H; Lee, Natuschka M

    2010-01-01

    Microbial mats in sulfidic cave streams offer unique opportunities to study redox-based biogeochemical nutrient cycles. Previous work from Lower Kane Cave, Wyoming, USA, focused on the aerobic portion of microbial mats, dominated by putative chemolithoautotrophic, sulfur-oxidizing groups within the Epsilonproteobacteria and Gammaproteobacteria. To evaluate nutrient cycling and turnover within the whole mat system, a multidisciplinary strategy was used to characterize the anaerobic portion of the mats, including application of the full-cycle rRNA approach, the most probable number method, and geochemical and isotopic analyses. Seventeen major taxonomic bacterial groups and one archaeal group were retrieved from the anaerobic portions of the mats, dominated by Deltaproteobacteria and uncultured members of the Chloroflexi phylum. A nutrient spiraling model was applied to evaluate upstream to downstream changes in microbial diversity based on carbon and sulfur nutrient concentrations. Variability in dissolved sulfide concentrations was attributed to changes in the abundance of sulfide-oxidizing microbial groups and shifts in the occurrence and abundance of sulfate-reducing microbes. Gradients in carbon and sulfur isotopic composition indicated that released and recycled byproduct compounds from upstream microbial activities were incorporated by downstream communities. On the basis of the type of available chemical energy, the variability of nutrient species in a spiraling model may explain observed differences in microbial taxonomic affiliations and metabolic functions, thereby spatially linking microbial diversity to nutrient spiraling in the cave stream ecosystem.

  20. A simple coculture system shows mutualism between anaerobic faecalibacteria and epithelial Caco-2 cells.

    Science.gov (United States)

    Sadaghian Sadabad, Mehdi; von Martels, Julius Z H; Khan, Muhammed Tanweer; Blokzijl, Tjasso; Paglia, Giuseppe; Dijkstra, Gerard; Harmsen, Hermie J M; Faber, Klaas Nico

    2015-12-15

    Most gut bacteria are obligate anaerobes and are important for human health. However, little mechanistic insight is available on the health benefits of specific anaerobic gut bacteria. A main obstacle in generating such knowledge is the lack of simple and robust coculturing methods for anaerobic bacteria and oxygen-requiring human cells. Here, we describe the development of a coculture system for intestinal Caco-2 cells and an anaerobic symbiont, Faecalibacterium prausnitzii, making use of 50 mL culture tubes. F. prausnitzii was grown in 40 mL YCFAG-agar with glass-adhered Caco-2 cells placed on top in 10 mL DMEM medium. Grown for 18-36 h in a humidified incubator at 37 °C and 5% CO2, coverslip-attached Caco-2 cells promoted growth and metabolism of F. prausnitzii, while F. prausnitzii suppressed inflammation and oxidative stress in Caco-2 cells. F. prausnitzii did not compromise Caco-2 cell viability. Exogenously added porcine mucin also promoted growth of F. prausnitzii, suggesting that it may be part of the mechanism of Caco-2-stimulated growth of F. prausnitzii. This 'Human oxygen-Bacteria anaerobic' (HoxBan) coculturing system uniquely establishes host-microbe mutualism of a beneficial anaerobic gut microbe in vitro and principally allows the analysis of host-microbe interactions of pure and mixed cultures of bacteria and human cells.

  1. Anaerobic methane oxidation and aerobic methane production in an east African great lake (Lake Kivu)

    DEFF Research Database (Denmark)

    Roland, Fleur A.E.; Morana, Cédric; Darchambeau, François

    2018-01-01

    We investigated CH4 oxidation in the water column of Lake Kivu, a deep meromictic tropical lake with CH4-rich anoxic deep waters. Depth profiles of dissolved gases (CH4 and N2O) and a diversity of potential electron acceptors for anaerobic CH4 oxidation (NO3 −, SO4 2−, Fe and Mn oxides) were dete...

  2. Anaerobic soil disinfestation and Brassica seed meal amendment alter soil microbiology and system resistance

    Science.gov (United States)

    Brassica seed meal amendments and anaerobic soil disinfestation control a spectrum of soil-borne plant pathogens via a diversity of mechanisms. Transformations in microbial community structure and function in certain instances were determinants of disease control and enhanced plant performance. Fo...

  3. In vivo IgA coating of anaerobic bacteria in human faeces

    NARCIS (Netherlands)

    vanderWaaij, LA; Limburg, PC; Mesander, G; vanderWaaij, D

    The bacterial flora in the human colon, although extremely diverse, has a relatively stable composition and non-infectious anaerobic bacteria are dominant. The flora forms a pool of numerous different antigens separated from mucosal immunocompetent cells by just a single layer of epithelial cells.

  4. Clinical features of anaerobic orthopaedic infections.

    Science.gov (United States)

    Lebowitz, Dan; Kressmann, Benjamin; Gjoni, Shpresa; Zenelaj, Besa; Grosgurin, Olivier; Marti, Christophe; Zingg, Matthieu; Uçkay, Ilker

    2017-02-01

    Some patient populations and types of orthopaedic surgery could be at particular risk for anaerobic infections. In this retrospective cohort study of operated adult patients with infections from 2004 to 2014, we assessed obligate anaerobes and considered first clinical infection episodes. Anaerobes, isolated from intra-operative samples, were identified in 2.4% of 2740 surgical procedures, of which half (33/65; 51%) were anaerobic monomicrobial infections. Propionibacterium acnes, a penicillin and vancomycin susceptible pathogen, was the predominantly isolated anaerobe. By multivariate analysis, the presence of fracture fixation plates was the variable most strongly associated with anaerobic infection (odds ratio: 2.1, 95% CI: 1.3-3.5). Anaerobes were also associated with spondylodesis and polymicrobial infections. In contrast, it revealed less likely in native bone or prosthetic joint infections and was not related to prior antibiotic use. In conclusion, obligate anaerobes in our case series of orthopaedic infections were rare, and mostly encountered in infections related to trauma with open-fracture fixation devices rather than clean surgical site infection. Anaerobes were often co-pathogens, and cultures most frequently recovered P. acnes. These observations thus do not support changes in current practices such as broader anaerobe coverage for perioperative prophylaxis.

  5. Spatial separation of photosynthesis and ethanol production by cell type-specific metabolic engineering of filamentous cyanobacteria.

    Science.gov (United States)

    Ehira, Shigeki; Takeuchi, Takuto; Higo, Akiyoshi

    2018-02-01

    Cyanobacteria, which perform oxygenic photosynthesis, have drawn attention as hosts for the direct production of biofuels and commodity chemicals from CO 2 and H 2 O using light energy. Although cyanobacteria capable of producing diverse chemicals have been generated by metabolic engineering, anaerobic non-photosynthetic culture conditions are often necessary for their production. In this study, we conducted cell type-specific metabolic engineering of the filamentous cyanobacterium Anabaena sp. PCC 7120, which forms a terminally differentiated cell called a heterocyst with a semi-regular spacing of 10-15 cells. Because heterocysts are specialized cells for nitrogen fixation, the intracellular oxygen level of heterocysts is maintained very low even when adjacent cells perform oxygenic photosynthesis. Pyruvate decarboxylase of Zymomonas mobilis and alcohol dehydrogenase of Synechocystis sp. PCC 6803 were exclusively expressed in heterocysts. Ethanol production was concomitant with nitrogen fixation in genetically engineered Anabaena sp. PCC 7120. Engineering of carbon metabolism in heterocysts improved ethanol production, and strain ET14, with an extra copy of the invB gene expressed from a heterocyst-specific promoter, produced 130.9 mg L -1 of ethanol after 9 days. ET14 produced 1681.9 mg L -1 of ethanol by increasing the CO 2 supply. Ethanol production per heterocyst cell was approximately threefold higher than that per cell of unicellular cyanobacterium. This study demonstrates the potential of heterocysts for anaerobic production of biofuels and commodity chemicals under oxygenic photosynthetic conditions.

  6. 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...

  7. Application of a tetrazolium dye as an indicator of viability in anaerobic bacteria.

    Science.gov (United States)

    Bhupathiraju, V K; Hernandez, M; Landfear, D; Alvarez-Cohen, L

    1999-09-01

    The use of the redox dye 5-cyano-2,3,-ditolyl tetrazolium chloride (CTC) for evaluating the metabolic activity of aerobic bacteria has gained wide application in recent years. In this study, we examined the utility of CTC in capturing the metabolic activity of anaerobic bacteria. In addition, the factors contributing to abiotic reduction of CTC were also examined. CTC was used in conjunction with the fluorochrome 5-(4,6-dichlorotriazinyl) aminofluorescein (DTAF), that targets bacterial cell wall proteins, to quantitate the active fraction of total bacterial numbers. Facultative anaerobic bacteria, including Escherichia coli grown fermentatively, and Pseudomonas chlorophis, P. fluorescens, P. stutzeri, and P. pseudoalcalegenes subsp. pseudoalcalegenes grown under nitrate-reducing conditions, actively reduced CTC during all phases of growth. Greater than 95% of these cells accumulated intracellular CTC-formazan crystals during the exponential phase. Obligate anaerobic bacteria, including Syntrophus aciditrophicus grown fermentatively, Geobacter sulfurreducens grown with fumarate as the electron acceptor, Desulfovibrio desulfuricans subsp. desulfuricans and D. halophilus grown under sulfate-reducing conditions, Methanobacterium formicicum grown on formate, H2 and CO2, and Methanobacterium thermoautotrophicum grown autotrophically on H2 and CO2 all reduced CTC to intracellular CTC-formazan crystals. The optimal CTC concentration for all organisms examined was 5 mM. Anaerobic CTC incubations were not required for quantification of anaerobically grown cells. CTC-formazan production by all cultures examined was proportional to biomass production, and CTC reduction was observed even in the absence of added nutrients. CTC was reduced by culture fluids containing ferric citrate as electron acceptor following growth of either G. metallireducens or G. sulfurreducens. Abiotic reduction of CTC was observed in the presence of ascorbic acid, cysteine hydrochloride, dithiothreitol

  8. Anaerobic Biotransformation and Mobility of Pu and of Pu-EDTA

    Energy Technology Data Exchange (ETDEWEB)

    Xun, Luying

    2009-11-20

    The enhanced mobility of radionuclides by co-disposed chelating agent, ethylenediaminetetraacetate (EDTA), is likely to occur only under anaerobic conditions. Our extensive effort to enrich and isolate anaerobic EDTA-degrading bacteria has failed. Others has tried and also failed. To explain the lack of anaerobic biodegradation of EDTA, we proposed that EDTA has to be transported into the cells for metabolism. A failure of uptake may contribute to the lack of EDTA degradation under anaerobic conditions. We demonstrated that an aerobic EDTA-degrading bacterium strain BNC1 uses an ABC-type transporter system to uptake EDTA. The system has a periplasmic binding protein that bind EDTA and then interacts with membrane proteins to transport EDTA into the cell at the expense of ATP. The bind protein EppA binds only free EDTA with a Kd of 25 nM. The low Kd value indicates high affinity. However, the Kd value of Ni-EDTA is 2.4 x 10^(-10) nM, indicating much stronger stability. Since Ni and other trace metals are essential for anaerobic respiration, we conclude that the added EDTA sequestrates all trace metals and making anaerobic respiration impossible. Thus, the data explain the lack of anaerobic enrichment cultures for EDTA degradation. Although we did not obtain an EDTA degrading culture under anaerobic conditions, our finding may promote the use of certain metals that forms more stable metal-EDTA complexes than Pu(III)-EDTA to prevent the enhanced mobility. Further, our data explain why EDTA is the most dominant organic pollutant in surface waters, due to the lack of degradation of certain metal-EDTA complexes.

  9. Anaerobic Biotransformation and Mobility of Pu and of Pu-EDTA

    International Nuclear Information System (INIS)

    Xun, Luying

    2009-01-01

    The enhanced mobility of radionuclides by co-disposed chelating agent, ethylenediaminetetraacetate (EDTA), is likely to occur only under anaerobic conditions. Our extensive effort to enrich and isolate anaerobic EDTA-degrading bacteria has failed. Others has tried and also failed. To explain the lack of anaerobic biodegradation of EDTA, we proposed that EDTA has to be transported into the cells for metabolism. A failure of uptake may contribute to the lack of EDTA degradation under anaerobic conditions. We demonstrated that an aerobic EDTA-degrading bacterium strain BNC1 uses an ABC-type transporter system to uptake EDTA. The system has a periplasmic binding protein that bind EDTA and then interacts with membrane proteins to transport EDTA into the cell at the expense of ATP. The bind protein EppA binds only free EDTA with a Kd of 25 nM. The low Kd value indicates high affinity. However, the Kd value of Ni-EDTA is 2.4 x 10 -10 nM, indicating much stronger stability. Since Ni and other trace metals are essential for anaerobic respiration, we conclude that the added EDTA sequestrates all trace metals and making anaerobic respiration impossible. Thus, the data explain the lack of anaerobic enrichment cultures for EDTA degradation. Although we did not obtain an EDTA degrading culture under anaerobic conditions, our finding may promote the use of certain metals that forms more stable metal-EDTA complexes than Pu(III)-EDTA to prevent the enhanced mobility. Further, our data explain why EDTA is the most dominant organic pollutant in surface waters, due to the lack of degradation of certain metal-EDTA complexes.

  10. Metabolic Flexibility of Sulfate Reducing Bacteria

    Directory of Open Access Journals (Sweden)

    Caroline M. Plugge

    2011-05-01

    Full Text Available Dissimilatory sulfate-reducing prokaryotes (SRB are a very diverse group of anaerobic bacteria that are omnipresent in nature and play an imperative role in the global cycling of carbon and sulfur. In anoxic marine sediments sulfate reduction accounts for up to 50% of the entire organic mineralization in coastal and shelf ecosystems where sulfate diffuses several meters deep into the sediment. As a consequence, SRB would be expected in the sulfate-containing upper sediment layers, whereas methanogenic Archaea would be expected to succeed in the deeper sulfate-depleted layers of the sediment. Where sediments are high in organic matter, sulfate is depleted at shallow sediment depths, and biogenic methane production will occur. In the absence of sulfate, many SRB ferment organic acids and alcohols, producing hydrogen, acetate, and carbon dioxide, and may even rely on hydrogen- and acetate-scavenging methanogens to convert organic compounds to methane. SRB can establish two different life styles, and these can be termed as sulfidogenic and acetogenic, hydrogenogenic metabolism. The advantage of having different metabolic capabilities is that it raises the chance of survival in environments when electron acceptors become depleted. In marine sediments, SRB and methanogens do not compete but rather complement each other in the degradation of organic matter.Also in freshwater ecosystems with sulfate concentrations of only 10-200 μM, sulfate is consumed efficiently within the top several cm of the sediments. Here, many of the δ-Proteobacteria present have the genetic machinery to perform dissimilatory sulfate reduction, yet they have an acetogenic, hydrogenogenic way of life.In this review we evaluate the physiology and metabolic mode of SRB in relation with their environment.

  11. Anaerobic thermophilic culture-system

    Energy Technology Data Exchange (ETDEWEB)

    Ljungdahl, L G; Wiegel, J K.W.

    1981-04-14

    A mixed culture system of Thermoanaerobacter ethanolicus and Clostridium thermocellum is employed for anaerobic, thermophilic ethanol fermentation of cellulose. By cellulase action, monosaccharides are formed which inhibit the growth of C. thermocellum, but are fermented by T. ethanolicus. Thus, at a regulated pH-value of 7.5, this mixed culture system of micro organisms results in a cellulose fermentation with a considerably higher ethanol yield.

  12. Endocarditis caused by anaerobic bacteria.

    Science.gov (United States)

    Kestler, M; Muñoz, P; Marín, M; Goenaga, M A; Idígoras Viedma, P; de Alarcón, A; Lepe, J A; Sousa Regueiro, D; Bravo-Ferrer, J M; Pajarón, M; Costas, C; García-López, M V; Hidalgo-Tenorio, C; Moreno, M; Bouza, E

    2017-10-01

    Infective endocarditis (IE) caused by anaerobic bacteria is a rare and poorly characterized disease. Most data reported in the literature are from case reports [1-3]. Therefore, we assessed the situation of anaerobic IE (AIE) in Spain using the database of the Spanish Collaboration on Endocarditis (GAMES). We performed a prospective study from 2008 to 2016 in 26 Spanish centers. We included 2491 consecutive cases of definite IE (Duke criteria). Anaerobic bacteria caused 22 cases (0.9%) of definite IE. Median age was 66 years (IQR, 56-73), and 19 (86.4%) patients were men. Most patients (14 [63.6%]) had prosthetic valve IE and all episodes were left-sided: aortic valves, 12 (54.5%); and mitral valves, 8 (36.4%). The most common pathogens were Propionibacterium acnes (14 [63.6%]), Lactobacillus spp (3 [13.63%]), and Clostridium spp. (2 [9.0%]), and the infection was mainly odontogenic. Fifteen of the 22 patients (68.2%) underwent cardiac surgery. Mortality was 18.2% during admission and 5.5% after 1 year of follow-up. When patients with AIE were compared with the rest of the cohort, we found that although those with AIE had a similar age and Charlson comorbidity index, they were more likely to have community-acquired IE (86.4% vs. 60.9%, p = 0.01), have undergone cardiac surgery (68.2% vs 48.7% p = 0.06), and have had lower mortality rates during admission (18.2% vs. 27.3%). IE due to anaerobic bacteria is an uncommon disease that affects mainly prosthetic valves and frequently requires surgery. Otherwise, there are no major differences between AIE and IE caused by other microorganisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Simple and convenient method for culturing anaerobic bacteria.

    OpenAIRE

    Behbehani, M J; Jordan, H V; Santoro, D L

    1982-01-01

    A simple and convenient method for culturing anaerobic bacteria is described. Cultures can be grown in commercially available flasks normally used for preparation of sterile external solutions. A special disposable rubber flask closure maintains anaerobic conditions in the flask after autoclaving. Growth of a variety of anaerobic oral bacteria was comparable to that obtained after anaerobic incubation of broth cultures in Brewer Anaerobic Jars.

  14. Drug Targets and Mechanisms of Resistance in the Anaerobic Protozoa

    Science.gov (United States)

    Upcroft, Peter; Upcroft, Jacqueline A.

    2001-01-01

    The anaerobic protozoa Giardia duodenalis, Trichomonas vaginalis, and Entamoeba histolytica infect up to a billion people each year. G. duodenalis and E. histolytica are primarily pathogens of the intestinal tract, although E. histolytica can form abscesses and invade other organs, where it can be fatal if left untreated. T. vaginalis infection is a sexually transmitted infection causing vaginitis and acute inflammatory disease of the genital mucosa. T. vaginalis has also been reported in the urinary tract, fallopian tubes, and pelvis and can cause pneumonia, bronchitis, and oral lesions. Respiratory infections can be acquired perinatally. T. vaginalis infections have been associated with preterm delivery, low birth weight, and increased mortality as well as predisposing to human immunodeficiency virus infection, AIDS, and cervical cancer. All three organisms lack mitochondria and are susceptible to the nitroimidazole metronidazole because of similar low-redox-potential anaerobic metabolic pathways. Resistance to metronidazole and other drugs has been observed clinically and in the laboratory. Laboratory studies have identified the enzyme that activates metronidazole, pyruvate:ferredoxin oxidoreductase, to its nitroso form and distinct mechanisms of decreasing drug susceptibility that are induced in each organism. Although the nitroimidazoles have been the drug family of choice for treating the anaerobic protozoa, G. duodenalis is less susceptible to other antiparasitic drugs, such as furazolidone, albendazole, and quinacrine. Resistance has been demonstrated for each agent, and the mechanism of resistance has been investigated. Metronidazole resistance in T. vaginalis is well documented, and the principal mechanisms have been defined. Bypass metabolism, such as alternative oxidoreductases, have been discovered in both organisms. Aerobic versus anaerobic resistance in T. vaginalis is discussed. Mechanisms of metronidazole resistance in E. histolytica have recently

  15. Metatranscriptomic and metagenomic description of the bacterial nitrogen metabolism in waste water wet oxidation effluents

    Directory of Open Access Journals (Sweden)

    Julien Crovadore

    2017-10-01

    Full Text Available Anaerobic digestion is a common method for reducing the amount of sludge solids in used waters and enabling biogas production. The wet oxidation process (WOX improves anaerobic digestion by converting carbon into methane through oxidation of organic compounds. WOX produces effluents rich in ammonia, which must be removed to maintain the activity of methanogens. Ammonia removal from WOX could be biologically operated by aerobic granules. To this end, granulation experiments were conducted in 2 bioreactors containing an activated sludge (AS. For the first time, the dynamics of the microbial community structure and the expression levels of 7 enzymes of the nitrogen metabolism in such active microbial communities were followed in regard to time by metagenomics and metatranscriptomics. It was shown that bacterial communities adapt to the wet oxidation effluent by increasing the expression level of the nitrogen metabolism, suggesting that these biological activities could be a less costly alternative for the elimination of ammonia, resulting in a reduction of the use of chemicals and energy consumption in sewage plants. This study reached a strong sequencing depth (from 4.4 to 7.6 Gb and enlightened a yet unknown diversity of the microorganisms involved in the nitrogen pathway. Moreover, this approach revealed the abundance and expression levels of specialised enzymes involved in nitrification, denitrification, ammonification, dissimilatory nitrate reduction to ammonium (DNRA and nitrogen fixation processes in AS. Keywords: Applied sciences, Biological sciences, Environmental science, Genetics, Microbiology

  16. Anaerobic degradation of landfill leachate using an upflow anaerobic fixed-bed reactor with microbial sulfate reduction

    International Nuclear Information System (INIS)

    Ben Dhia Thabet, Olfa; Bouallagui, Hassib; Cayol, Jean-luc; Ollivier, Bernard; Fardeau, Marie-Laure; Hamdi, Moktar

    2009-01-01

    This study evaluated the anaerobic degradation of landfill leachate and sulfate reduction as a function of COD/(SO 4 2- ) ratio in an upflow anaerobic fixed-bed reactor. The reactor, which was inoculated with a mixed consortium, was operated under a constant hydraulic retention time (HRT) of 5 days. We investigated the effect of COD/(SO 4 2- ) ratio variation on the sulfate reduction efficiency, hydrogen sulfide production, chemical oxygen demand (COD) removal, conductivity, and pH variation. The best reactor performance, with significant sulfate reduction efficiency and COD removal efficiency of 91% and 87%, respectively, was reached under a COD/(SO 4 2- ) ratio of 1.17. Under these conditions, microscopic analysis showed the abundance of vibrios and rod-shaped bacterial cells. Two anaerobic bacteria were isolated from the reactor sludge. Phylogenetic studies performed on these strains identified strain A1 as affiliated to Clostridium genus and strain H1 as a new species of sulfate-reducing bacteria affiliated to the Desulfovibrio genus. The closest phylogenetic relative of strain H1 was Desulfovibrio desulfuricans, at 96% similarity for partial 16S RNA gene sequence data. Physiological and metabolic characterization was performed for this strain.

  17. 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

  18. Engineering of the redox imbalance of Fusarium oxysporum enables anaerobic growth on xylose.

    Science.gov (United States)

    Panagiotou, Gianni; Christakopoulos, Paul; Grotkjaer, Thomas; Olsson, Lisbeth

    2006-09-01

    Dissimilatory nitrate reduction metabolism, of the natural xylose-fermenting fungus Fusarium oxysporum, was used as a strategy to achieve anaerobic growth and ethanol production from xylose. Beneficial alterations of the redox fluxes and thereby of the xylose metabolism were obtained by taking advantage of the regeneration of the cofactor NAD(+) during the denitrification process. In batch cultivations, nitrate sustained growth under anaerobic conditions (1.21 g L(-1) biomass) and simultaneously a maximum yield of 0.55 moles of ethanol per mole of xylose was achieved, whereas substitution of nitrate with ammonium limited the growth significantly (0.15 g L(-1) biomass). Using nitrate, the maximum acetate yield was 0.21 moles per mole of xylose and no xylitol excretion was observed. Furthermore, the network structure in the central carbon metabolism of F. oxysporum was characterized in steady state. F. oxysporum grew anaerobically on [1-(13)C] labelled glucose and unlabelled xylose in chemostat cultivation with nitrate as nitrogen source. The use of labelled substrate allowed the precise determination of the glucose and xylose contribution to the carbon fluxes in the central metabolism of this poorly described microorganism. It was demonstrated that dissimilatory nitrate reduction allows F. oxysporum to exhibit typical respiratory metabolic behaviour with a highly active TCA cycle and a large demand for NADPH.

  19. Plasma protein carbonyl responses to anaerobic exercise in female cyclists

    Directory of Open Access Journals (Sweden)

    M.E Afzalpour

    2016-03-01

    Full Text Available Single bouts of aerobic exercise may leads to oxidative stress due to the use of oxygen for metabolism and the generation of reactive oxygen. In athletes, oxidative stress can lead to several deleterious performance effects, such as muscular oxidative damage, muscle soreness, loss of skeletal muscle force production and/or inflammation. However, little is known regarding the severity and duration of oxidative stress arising from intensive anaerobic modes of exercise in aerobically-trained athletes. The purpose of this study was to investigate the effect of a single bout of intensive anaerobic exercise on plasma protein carbonyl (PC in aerobically-trained women. Aerobically-trained, provincial female cyclists [n = 18, age: 24.2±2.7 years; stature: 163.6±4.6 cm; body mass: 53.4±4.2 kg] were randomly assigned into either a non-exercising control (CON; n = 9 or experimental (EXP; n = 9 group that underwent a 30-second anaerobic (Wingate cycle ergometer exercise session. Blood sampling took place before exercise, immediately after the exercise (IE, and 24 hours following the exercise (24HR bout. In the EXP, results indicated significant (P ≤ 0.05 differences in PC levels between the pre-test and IE (0.010±0.0124 to 0.0149±0.0420 mmol/milt; P = 0.010, and IE and 24HR (0.0149±0.0420 to 0.0111±0.0183 mmol/milt; P = 0.013. No significant differences were observed between pre-test and 24HR (0.010±0.0124 to 0.0111±0.0183 mmol/milt; P = 0.371. These results indicate that oxidative protein damage, as indicated by PC levels, rises immediately with the onset of anaerobic exercise, but returns to resting levels within 24 hours following exercise in aerobically-trained women.

  20. 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...

  1. Diversity of apolipoprotein E genetic polymorphism significance on cardiovascular risk is determined by the presence of metabolic syndrome among hypertensive patients.

    Science.gov (United States)

    Teixeira, Andrei Alkmim; Marrocos, Mauro Sergio; Quinto, Beata Marie Redublo; Dalboni, Maria Aparecida; Rodrigues, Cassio Jose de Oliveira; Carmona, Silmara de Melo; Kuniyoshi, Mariana; Batista, Marcelo Costa

    2014-11-20

    Hypertension has a significant relevance as a cardiovascular risk factor. A consistent increase on world's Metabolic Syndrome (MetS) incidence has been associated with an epidemic cardiovascular risk in different populations. Dislipidemia plays a major role determining the epidemic CV burden attributed to MetS. Apolipoprotein E (ApoE) is involved on cholesterol and triglycerides metabolism regulation. Once ApoE polymorphism may influence lipid metabolism, it is possible that it brings on individual susceptibility consequences for the development of MetS and cardiovascular risk. The objective of the study is to measure the discriminatory power of ApoE polymorphism in determining cardiovascular risk stratification based on the presence MetS in a cohort of hypertensive patients. It was enrolled 383 patients, divided in two groups, classified by MetS presence (IDF criteria): Group 1: 266 patients with MetS (MetS +) and Group 2: 117 patients without Mets (MetS -). Patient's data were collected by clinical evaluation, physical exam, file reviews and laboratory testing. Polymorphic ApoE analysis was performed by PCR amplification. Groups were compared on clinical and laboratory characteristics as well as allele and genotype distribution towards ApoE polymorphism. Mets CVD prevalence was analysed according to E4 allele prevalence. The results evidenced 184 men (48%), 63,7% whites, 45,1% diabetics and 11,7% of patients were smokers. Mean age was 64,0 ± 12,0 years. When genotypic distribution was analyzed, E3/3 genotype and E3 allele frequencies were more prevalent. Among patients with MetS, we observed an independent association between CVD prevalence and E4 allele frequency (OR 2.42 (1.17- 5.0, p < 0,05)). On the opposite direction, in those without MetS, there was lesser CVD burden in E4 allele carriers (OR 0,14 (0,02-0,75)). These associations remained significant even after confounding factor corrections. The results presented demonstrate that the association

  2. Quantitative proteome-level analysis of paulownia witches’ broom disease with methyl methane sulfonate assistance reveals diverse metabolic changes during the infection and recovery processes

    Directory of Open Access Journals (Sweden)

    Zhe Wang

    2017-07-01

    Full Text Available Paulownia witches’ broom (PaWB disease caused by phytoplasma is a fatal disease that leads to considerable economic losses. Although there are a few reports describing studies of PaWB pathogenesis, the molecular mechanisms underlying phytoplasma pathogenicity in Paulownia trees remain uncharacterized. In this study, after building a transcriptome database containing 67,177 sequences, we used isobaric tags for relative and absolute quantification (iTRAQ to quantify and analyze the proteome-level changes among healthy P. fortunei (PF, PaWB-infected P. fortunei (PFI, and PaWB-infected P. fortunei treated with 20 mg L−1 or 60 mg L−1 methyl methane sulfonate (MMS (PFI-20 and PFI-60, respectively. A total of 2,358 proteins were identified. We investigated the proteins profiles in PF vs. PFI (infected process and PFI-20 vs. PFI-60 (recovered process, and further found that many of the MMS-response proteins mapped to “photosynthesis” and “ribosome” pathways. Based on our comparison scheme, 36 PaWB-related proteins were revealed. Among them, 32 proteins were classified into three functional groups: (1 carbohydrate and energy metabolism, (2 protein synthesis and degradation, and (3 stress resistance. We then investigated the PaWB-related proteins involved in the infected and recovered processes, and discovered that carbohydrate and energy metabolism was inhibited, and protein synthesis and degradation decreased, as the plant responded to PaWB. Our observations may be useful for characterizing the proteome-level changes that occur at different stages of PaWB disease. The data generated in this study may serve as a valuable resource for elucidating the pathogenesis of PaWB disease during phytoplasma infection and recovery stages.

  3. Methane-metabolizing microbial communities in sediments of the Haima cold seep area, northwest slope of the South China Sea.

    Science.gov (United States)

    Niu, Mingyang; Fan, Xibei; Zhuang, Guangchao; Liang, Qianyong; Wang, Fengping

    2017-09-01

    Cold seeps are widespread chemosynthetic ecosystems in the deep-sea environment, and cold seep microbial communities of the South China Sea are poorly constrained. Here we report on the archaeal communities, particularly those involved in methane metabolization, in sediments of a newly discovered cold seep (named 'Haima') on the northwest slope of the South China Sea. Archaeal diversity, abundance and distribution were investigated in two piston cores collected from a seep area (QDN-14B) and a non-seep control site (QDN-31B). Geochemical investigation of the QDN-14B core identified an estimated sulfate-methane transition zone (Estimated SMTZ) at 300-400 cm below sea floor (cmbsf), where a high abundance of anaerobic methane-oxidizing archaea (ANME) occurred, as revealed by analysis of the 16S rRNA gene and the gene (mcrA) encoding the α-subunit of the key enzyme methyl-coenzyme M reductase. ANME-2a/b was predominant in the upper and middle layers of the estimated SMTZ, whereas ANME-1b outcompeted ANME-2 in the sulfate-depleted bottom layers of the estimated SMTZ and the methanogenic zone. Fine-scale phylogenetic analysis further divided the ANME-1b group into three subgroups with different distribution patterns: ANME-1bI, ANME-1bII and ANME-1bIII. Multivariate analyses indicated that dissolved inorganic carbon and sulfate may be important factors controlling the composition of the methane-metabolizing community. Our study on ANME niche separation and interactions with other archaeal groups improves our understanding of the metabolic diversity and flexibility of ANME, and the findings further suggest that ANME subgroups may have evolved diversified/specified metabolic capabilities other than syntrophic anaerobic oxidation of methane coupled with sulfate reduction in marine sediments. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Intrinsic kinetic parameters of substrate utilization by immobilized anaerobic sludge.

    Science.gov (United States)

    Zaiat, M; Vieira, L G; Foresti, E

    1997-01-20

    This article presents a method for evaluating the intrinsic kinetic parameters of the specific substrate utilization rate (r) equation and discusses the results obtained for anaerobic sludge-bed samples taken from a horizontal-flow anaerobic immobilized sludge (HAIS) reactor. This method utilizes a differential reactor filled with polyurethane foam matrices containing immobilized anaerobic sludge which is subjected to a range of feeding substrate flow rates. The range of liquid superficial velocities thus obtained are used for generating data of observed specific substrate utilization rates (r(obs)) under a diversity of external mass transfer resistance conditions. The r(obs) curves are then adjusted to permit their extrapolation for the condition of no external mass transfer resistance, and the values determined are used as a test for the condition of absence of limitation of internal mass transfer. The intrinsic parameters r(max), the maximum specific substrate utilization rate, and K(s), the half-velocity coefficient, are evaluated from the r values under no external mass transfer resistance and no internal mass transfer limitation. The application of such a method for anaerobic sludge immobilized in polyurethane foam particles treating a glucose substrate at 30 degrees C resulted in intrinsic r(max) and K(s), respectively, of 0.330 mg chemical oxygen demand (COD) . mg(-1) volatile suspended solids (VSS) . h(-1) and 72 mg COD . L(-1). In comparison with the values found in the literature, intrinsic r(max) is significantly high and intrinsic K(s) is relatively low. (c) 1997 John Wiley & Sons, Inc.

  5. Isolation of a human intestinal anaerobe, Bifidobacterium sp. strain SEN, capable of hydrolyzing sennosides to sennidins.

    Science.gov (United States)

    Akao, T; Che, Q M; Kobashi, K; Yang, L; Hattori, M; Namba, T

    1994-01-01

    A strictly anaerobic bacterium capable of metabolizing sennosides was isolated from human feces and identified as Bifidobacterium sp., named strain SEN. The bacterium hydrolyzed sennosides A and B to sennidins A and B via sennidin A and B 8-monoglucosides, respectively. Among nine species of Bifidobacterium having beta-glucosidase activity, only Bifidobacterium dentium and B. adolescentis metabolized sennoside B to sennidin B, suggesting that the sennoside-metabolizing bacteria produce a novel type of beta-glucosidase capable of hydrolyzing sennosides to sennidins. PMID:8161172

  6. Taurine does not affect the composition, diversity, or metabolism of human colonic microbiota simulated in a single-batch fermentation system.

    Science.gov (United States)

    Sasaki, Kengo; Sasaki, Daisuke; Okai, Naoko; Tanaka, Kosei; Nomoto, Ryohei; Fukuda, Itsuko; Yoshida, Ken-Ichi; Kondo, Akihiko; Osawa, Ro

    2017-01-01

    Accumulating evidence suggests that dietary taurine (2-aminoethanesulfonic acid) exerts beneficial anti-inflammatory effects in the large intestine. In this study, we investigated the possible impact of taurine on human colonic microbiota using our single-batch fermentation system (Kobe University Human Intestinal Microbiota Model; KUHIMM). Fecal samples from eight humans were individually cultivated with and without taurine in the KUHIMM. The results showed that taurine remained largely undegraded after 30 h of culturing in the absence of oxygen, although some 83% of the taurine was degraded after 30 h of culturing under aerobic conditions. Diversity in bacterial species in the cultures was analyzed by 16S rRNA gene sequencing, revealing that taurine caused no significant change in the diversity of the microbiota; both operational taxonomic unit and Shannon-Wiener index of the cultures were comparable to those of the respective source fecal samples. In addition, principal coordinate analysis indicated that taurine did not alter the composition of bacterial species, since the 16S rRNA gene profile of bacterial species in the original fecal sample was maintained in each of the cultures with and without taurine. Furthermore, metabolomic analysis revealed that taurine did not affect the composition of short-chain fatty acids produced in the cultures. These results, under these controlled but artificial conditions, suggested that the beneficial anti-inflammatory effects of dietary taurine in the large intestine are independent of the intestinal microbiota. We infer that dietary taurine may act directly in the large intestine to exert anti-inflammatory effects.

  7. Iron biomineralization by anaerobic neutrophilic iron-oxidizing bacteria

    DEFF Research Database (Denmark)

    Miot, Jennyfer; Benzerara, Karim; Morin, Guillaume

    2009-01-01

    Minerals formed by bio-oxidation of ferrous iron (Fe(II)) at neutral pH, their association with bacterial ultrastructures as well as their impact on the metabolism of iron-oxidizing bacteria remain poorly understood. Here, we investigated iron biomineralization by the anaerobic nitrate-dependent ......Minerals formed by bio-oxidation of ferrous iron (Fe(II)) at neutral pH, their association with bacterial ultrastructures as well as their impact on the metabolism of iron-oxidizing bacteria remain poorly understood. Here, we investigated iron biomineralization by the anaerobic nitrate...... precipitation in the periplasm (in a few tens of minutes), followed by the formation of surface-bound globules. Moreover, we frequently observed an asymmetric mineral thickening at the cell poles. In parallel, the evolution of iron oxidation was quantified by STXM: iron both contained in the bacteria...... and in the extracellular precipitates reached complete oxidation within 6 days. While a progressive oxidation of Fe in the bacteria and in the medium could be observed, spatial redox (oxido-reduction state) heterogeneities were detected at the cell poles and in the extracellular precipitates after 1 day. All...

  8. Activation of Acetone and Other Simple Ketones in Anaerobic Bacteria.

    Science.gov (United States)

    Heider, Johann; Schühle, Karola; Frey, Jasmin; Schink, Bernhard

    2016-01-01

    Acetone and other ketones are activated for subsequent degradation through carboxylation by many nitrate-reducing, phototrophic, and obligately aerobic bacteria. Acetone carboxylation leads to acetoacetate, which is subsequently activated to a thioester and degraded via thiolysis. Two different types of acetone carboxylases have been described, which require either 2 or 4 ATP equivalents as an energy supply for the carboxylation reaction. Both enzymes appear to combine acetone enolphosphate with carbonic phosphate to form acetoacetate. A similar but more complex enzyme is known to carboxylate the aromatic ketone acetophenone, a metabolic intermediate in anaerobic ethylbenzene metabolism in denitrifying bacteria, with simultaneous hydrolysis of 2 ATP to 2 ADP. Obligately anaerobic sulfate-reducing bacteria activate acetone to a four-carbon compound as well, but via a different process than bicarbonate- or CO2-dependent carboxylation. The present evidence indicates that either carbon monoxide or a formyl residue is used as a cosubstrate, and that the overall ATP expenditure of this pathway is substantially lower than in the known acetone carboxylase reactions. © 2016 S. Karger AG, Basel.

  9. Thermodynamic principles governing metabolic operation : inference, analysis, and prediction

    NARCIS (Netherlands)

    Niebel, Bastian

    2015-01-01

    The principles governing metabolic flux are poorly understood. Because diverse organisms show similar metabolic flux patterns, we hypothesized that fundamental thermodynamic constraints might shape cellular metabolism. We developed a constraint-based model for Saccharomyces cerevisiae that included

  10. Increased number of anaerobic bacteria in the infected root canal in type 2 diabetic rats.

    Science.gov (United States)

    Iwama, Akihiro; Morimoto, Taisuke; Tsuji, Masahito; Nakamura, Koki; Higuchi, Naoya; Imaizumi, Ichiro; Shibata, Naoki; Yamasaki, Masahiro; Nakamura, Hiroshi

    2006-05-01

    The purpose of this study was to investigate the relationship between type 2 diabetes mellitus and anaerobic bacteria detected in infected root canals. Normal Wistar rats (control) received a standard laboratory diet with water (group A), and GK rats (type 2 diabetes mellitus rats) a normal laboratory diet with water (group B) or a 30% sucrose solution (group C). Chemotaxis assay was conducted on polymorphonuclear leukocytes from the 3 groups, and the numbers of anaerobic bacteria in infected root canals were determined. In the chemotaxis assay on the polymorphonuclear leukocytes, the chemotactic response of cells in group C was lower than that for groups A and B (P obligate anaerobic bacteria which stained gram negative, were significantly more numerous in group C (P < .01) than in groups A and B. The metabolic condition produced by type 2 diabetes mellitus in rats might lower the general host resistance against bacterial infection.

  11. Specific characteristics of physical fitness at work anaerobic endurance type of rowers in canoe

    Directory of Open Access Journals (Sweden)

    Penchen Guo

    2014-12-01

    Full Text Available Purpose: to determine the effect of the reactive properties cardiorespiratory system to a special performance by canoe paddlers who specialize in the 200 m. Material : The study involved 22 paddler aged 18 - 29 years. Results : there were significant indicators of the reaction due to pulmonary performance and efficiency of anaerobic metabolism. The range of correlation coefficients (r was -0.54 - 0.77 (T 50 V E and 0,55-0,71 (V E. Conclusions : It was found that the optimization of the reactive properties of the cardiorespiratory system to realize the potential impact endurance rowers when using anaerobic nature. The greatest number of significant connections were indicators of efficiency and response of pulmonary ventilation. This allowed the evaluation of the functional improve information security work and increase specialized training sessions focus in the development of anaerobic endurance while working character in canoeing.

  12. Genome Analysis of the Biotechnologically Relevant Acidophilic Iron Oxidising Strain JA12 Indicates Phylogenetic and Metabolic Diversity within the Novel Genus “Ferrovum”

    Science.gov (United States)

    Ullrich, Sophie R.; Poehlein, Anja; Tischler, Judith S.; González, Carolina; Ossandon, Francisco J.; Daniel, Rolf; Holmes, David S.; Schlömann, Michael; Mühling, Martin

    2016-01-01

    Background Members of the genus “Ferrovum” are ubiquitously distributed in acid mine drainage (AMD) waters which are characterised by their high metal and sulfate loads. So far isolation and microbiological characterisation have only been successful for the designated type strain “Ferrovum myxofaciens” P3G. Thus, knowledge about physiological characteristics and the phylogeny of the genus “Ferrovum” is extremely scarce. Objective In order to access the wider genetic pool of the genus “Ferrovum” we sequenced the genome of a “Ferrovum”-containing mixed culture and successfully assembled the almost complete genome sequence of the novel “Ferrovum” strain JA12. Phylogeny and Lifestyle The genome-based phylogenetic analysis indicates that strain JA12 and the type strain represent two distinct “Ferrovum” species. “Ferrovum” strain JA12 is characterised by an unusually small genome in comparison to the type strain and other iron oxidising bacteria. The prediction of nutrient assimilation pathways suggests that “Ferrovum” strain JA12 maintains a chemolithoautotrophic lifestyle utilising carbon dioxide and bicarbonate, ammonium and urea, sulfate, phosphate and ferrous iron as carbon, nitrogen, sulfur, phosphorous and energy sources, respectively. Unique Metabolic Features The potential utilisation of urea by “Ferrovum” strain JA12 is moreover remarkable since it may furthermore represent a strategy among extreme acidophiles to cope with the acidic environment. Unlike other acidophilic chemolithoautotrophs “Ferrovum” strain JA12 exhibits a complete tricarboxylic acid cycle, a metabolic feature shared with the closer related neutrophilic iron oxidisers among the Betaproteobacteria including Sideroxydans lithotrophicus and Thiobacillus denitrificans. Furthermore, the absence of characteristic redox proteins involved in iron oxidation in the well-studied acidophiles Acidithiobacillus ferrooxidans (rusticyanin) and Acidithiobacillus

  13. ANAEROBIC BIODEGRADATION OF A BIODEGRADABLE MATERIAL UNDER ANAEROBIC - THERMOPHILIC DIGESTION

    Directory of Open Access Journals (Sweden)

    RICARDO CAMACHO-MUÑOZ

    2014-12-01

    Full Text Available This paper dertermined the anaerobic biodegradation of a polymer obtained by extrusion process of native cassava starch, polylactic acid and polycaprolactone. Initially a thermophilic - methanogenic inoculum was prepared from urban solid waste. The gas final methane concentration and medium’s pH reached values of 59,6% and 7,89 respectively. The assay assembly was carried out according ASTM D5511 standard. The biodegradation percent of used materials after 15 day of digestion were: 77,49%, 61,27%, 0,31% for cellulose, sample and polyethylene respectively. Due cellulose showed biodegradation levels higher than 70% it’s deduced that the inoculum conditions were appropriate. A biodegradation level of 61,27%, 59,35% of methane concentration in sample’s evolved gas and a medium’s finale pH of 7,71 in sample’s vessels, reveal the extruded polymer´s capacity to be anaerobically degraded under thermophilic- high solid concentration conditions.

  14. Evaluation of microorganisms with sulfidogenic metabolic potential under anaerobic conditions

    Directory of Open Access Journals (Sweden)

    Isabel Kimiko Sakamoto

    2012-10-01

    Full Text Available The aim of this work was to identify groups of microorganisms that are capable of degrading organic matter utilizing sulfate as an electron acceptor. The assay applied for this purpose consisted of running batch reactors and monitoring lactate consumption, sulfate reduction and sulfide production. A portion of the lactate added to the batch reactors was consumed, and the remainder was converted into acetic, propionic and butyric acid after 111 hours of operation These results indicate the presence of sulfate-reducing bacteria (SRB catalyzing both complete and incomplete oxidation of organic substrates. The sulfate removal efficiency was 49.5% after 1335 hours of operation under an initial sulfate concentration of 1123 mg/L. The SRB concentrations determined by the most probable number (MPN method were 9.0x10(7 cells/mL at the beginning of the assay and 8.0x10(5 cells/mL after 738 hours of operation.

  15. Gut Microbiota and Metabolic Disorders

    Directory of Open Access Journals (Sweden)

    Kyu Yeon Hur

    2015-06-01

    Full Text Available Gut microbiota plays critical physiological roles in the energy extraction and in the control of local or systemic immunity. Gut microbiota and its disturbance also appear to be involved in the pathogenesis of diverse diseases including metabolic disorders, gastrointestinal diseases, cancer, etc. In the metabolic point of view, gut microbiota can modulate lipid accumulation, lipopolysaccharide content and the production of short-chain fatty acids that affect food intake, inflammatory tone, or insulin signaling. Several strategies have been developed to change gut microbiota such as prebiotics, probiotics, certain antidiabetic drugs or fecal microbiota transplantation, which have diverse effects on body metabolism and on the development of metabolic disorders.

  16. Systems Level Dissection of Anaerobic Methane Cycling: Quantitative Measurements of Single Cell Ecophysiology, Genetic Mechanisms, and Microbial Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Orphan, Victoria [California Inst. of Technology (CalTech), Pasadena, CA (United States); Tyson, Gene [University of Queensland, Brisbane Australia; Meile, Christof [University of Georgia, Athens, Georgia; McGlynn, Shawn [California Inst. of Technology (CalTech), Pasadena, CA (United States); Yu, Hang [California Inst. of Technology (CalTech), Pasadena, CA (United States); Chadwick, Grayson [California Inst. of Technology (CalTech), Pasadena, CA (United States); Marlow, Jeffrey [California Inst. of Technology (CalTech), Pasadena, CA (United States); Trembath-Reichert, Elizabeth [California Inst. of Technology (CalTech), Pasadena, CA (United States); Dekas, Anne [California Inst. of Technology (CalTech), Pasadena, CA (United States); Hettich, Robert [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pan, Chongle [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ellisman, Mark [University of California San Diego; Hatzenpichler, Roland [California Inst. of Technology (CalTech), Pasadena, CA (United States); Skennerton, Connor [California Inst. of Technology (CalTech), Pasadena, CA (United States); Scheller, Silvan [California Inst. of Technology (CalTech), Pasadena, CA (United States)

    2017-12-25

    The global biological CH4 cycle is largely controlled through coordinated and often intimate microbial interactions between archaea and bacteria, the majority of which are still unknown or have been only cursorily identified. Members of the methanotrophic archaea, aka ‘ANME’, are believed to play a major role in the cycling of methane in anoxic environments coupled to sulfate, nitrate, and possibly iron and manganese oxides, frequently forming diverse physical and metabolic partnerships with a range of bacteria. The thermodynamic challenges overcome by the ANME and their bacterial partners and corresponding slow rates of growth are common characteristics in anaerobic ecosystems, and, in stark contrast to most cultured microorganisms, this type of energy and resource limited microbial lifestyle is likely the norm in the environment. While we have gained an in-depth systems level understanding of fast-growing, energy-replete microorganisms, comparatively little is known about the dynamics of cell respiration, growth, protein turnover, gene expression, and energy storage in the slow-growing microbial majority. These fundamental properties, combined with the observed metabolic and symbiotic versatility of methanotrophic ANME, make these cooperative microbial systems a relevant (albeit challenging) system to study and for which to develop and optimize culture-independent methodologies, which enable a systems-level understanding of microbial interactions and metabolic networks. We used an integrative systems biology approach to study anaerobic sediment microcosms and methane-oxidizing bioreactors and expanded our understanding of the methanotrophic ANME archaea, their interactions with physically-associated bacteria, ecophysiological characteristics, and underlying genetic basis for cooperative microbial methane-oxidation linked with different terminal electron acceptors. Our approach is inherently multi-disciplinary and multi-scaled, combining transcriptional and

  17. Microbial diversity in subseafloor fluids from Explorer Ridge, Northeast Pacific

    Science.gov (United States)

    Bolton, S.; Huber, J. A.; Embley, R.; Butterfield, D. A.; Baross, J. A.

    2003-12-01

    The Gorda, Juan de Fuca and Explorer Ridges are first order spreading centers located in the northeast Pacific. While the Gorda and Juan de Fuca Ridges have been extensively sampled for chemical and microbiological analyses, what little is known about the Explorer Ridge is from preliminary observations made in the mid-1980's. A cruise in 2002 revisited the area and discovered vigorous hydrothermal activity at Magic Mountain, a site located outside the primary rift valley. Explorer Ridge is an important site to compare with other well-described vent sites on the Juan de Fuca Ridge. Our research has focused on describing the phylogenetic and physiological diversity of bacteria and archaea in low temperature hydrothermal fluids in an effort to identify subseafloor indicator organisms and to use the physiological characteristics of these organisms to help constrain subseafloor habitat characteristics. We have previously established that there are microbial taxa that are unique to subseafloor habitats associated with diffuse flow fluids at Axial Seamount and at Endeavour both located on the Juan de Fuca Ridge. These included cultured anaerobic, thermophilic and hyperthermophilic heterotrophs, methanogens and sulfur metabolizers. Moreover, results from molecular phylogeny analyses using the 16S rRNA sequences identified a phylogenetically diverse group of bacteria belonging to the epsilon-proteobacteria. While anaerobic hyperthermophiles were cultured from some diffuse-flow vent sites at Explorer, they were less abundant than at Axial Volcano and Endeavour, and curiously, no methanogens were cultured or detected in 16S rRNA clonal libraries. Like Axial, a diverse group of epsilon-proteobacterial clones were found with many similar to those identified from Axial Seamount and other hydrothermal vent sites, although there appears to be some unique species. The overall bacterial diversity at Explorer appears different than at Axial, possibly linked to temperature or chemical

  18. Anaerobic co-digestion of Tunisian green macroalgae Ulva rigida with sugar industry wastewater for biogas and methane production enhancement.

    Science.gov (United States)

    Karray, Raida; Karray, Fatma; Loukil, Slim; Mhiri, Najla; Sayadi, Sami

    2017-03-01

    Ulva rigida is a green macroalgae, abundantly available in the Mediterranean which offers a promising source for the production of valuable biomaterials, including methane. In this study, anaerobic digestion assays in a batch mode was performed to investigate the effects of various inocula as a mixture of fresh algae, bacteria, fungi and sediment collected from the coast of Sfax, on biogas production from Ulva rigida. The results revealed that the best inoculum to produce biogas and feed an anaerobic reactor is obtained through mixing decomposed macroalgae with anaerobic sludge and water, yielding into 408mL of biogas. The process was then investigated in a sequencing batch reactor (SBR) which led to an overall biogas production of 375mL with 40% of methane. Further co-digestion studies were performed in an anaerobic up-flow bioreactor using sugar wastewater as a co-substrate. A high biogas production yield of 114mL g -1 VS added was obtained with 75% of methane. The co-digestion proposed in this work allowed the recovery of natural methane, providing a promising alternative to conventional anaerobic microbial fermentation using Tunisian green macroalgae. Finally, in order to identify the microbial diversity present in the reactor during anaerobic digestion of Ulva rigida, the prokaryotic diversity was investigated in this bioreactor by the denaturing gradient gel electrophoresis (DGGE) method targeting the 16S rRNA gene. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Method for anaerobic fermentation and biogas production

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to a method for biomass processing, anaerobic fermentation of the processed biomass, and the production biogas. In particular, the invention relates to a system and method for generating biogas from anaerobic fermentation of processed organic material that comprises...

  20. Integrated anaerobic and aerobic treatment of sewage

    NARCIS (Netherlands)

    Wang, K.

    1994-01-01

    This thesis describes results of investigations dealing with sequential concept of anaerobic-aerobic treatment of municipal wastewater. The main purposes of the study were 1) to develop a proper anaerobic hydrolytic pretreatment unit, consisting of a Hydrolysis Upflow Sludge Bed (HUSB-)

  1. Genome Analysis of the Biotechnologically Relevant Acidophilic Iron Oxidising Strain JA12 Indicates Phylogenetic and Metabolic Diversity within the Novel Genus "Ferrovum".

    Directory of Open Access Journals (Sweden)

    Sophie R Ullrich

    Full Text Available Members of the genus "Ferrovum" are ubiquitously distributed in acid mine drainage (AMD waters which are characterised by their high metal and sulfate loads. So far isolation and microbiological characterisation have only been successful for the designated type strain "Ferrovum myxofaciens" P3G. Thus, knowledge about physiological characteristics and the phylogeny of the genus "Ferrovum" is extremely scarce.In order to access the wider genetic pool of the genus "Ferrovum" we sequenced the genome of a "Ferrovum"-containing mixed culture and successfully assembled the almost complete genome sequence of the novel "Ferrovum" strain JA12.The genome-based phylogenetic analysis indicates that strain JA12 and the type strain represent two distinct "Ferrovum" species. "Ferrovum" strain JA12 is characterised by an unusually small genome in comparison to the type strain and other iron oxidising bacteria. The prediction of nutrient assimilation pathways suggests that "Ferrovum" strain JA12 maintains a chemolithoautotrophic lifestyle utilising carbon dioxide and bicarbonate, ammonium and urea, sulfate, phosphate and ferrous iron as carbon, nitrogen, sulfur, phosphorous and energy sources, respectively.The potential utilisation of urea by "Ferrovum" strain JA12 is moreover remarkable since it may furthermore represent a strategy among extreme acidophiles to cope with the acidic environment. Unlike other acidophilic chemolithoautotrophs "Ferrovum" strain JA12 exhibits a complete tricarboxylic acid cycle, a metabolic feature shared with the closer related neutrophilic iron oxidisers among the Betaproteobacteria including Sideroxydans lithotrophicus and Thiobacillus denitrificans. Furthermore, the absence of characteristic redox proteins involved in iron oxidation in the well-studied acidophiles Acidithiobacillus ferrooxidans (rusticyanin and Acidithiobacillus ferrivorans (iron oxidase indicates the existence of a modified pathway in "Ferrovum" strain JA12

  2. 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.

  3. Degradative capacities and bioaugmentation potential of an anaerobic benzene-degrading bacterium strain DN11

    Energy Technology Data Exchange (ETDEWEB)

    Yuki Kasai; Yumiko Kodama; Yoh Takahata; Toshihiro Hoaki; Kazuya Watanabe [Marine Biotechnology Institute, Kamaishi (Japan)

    2007-09-15

    Azoarcus sp. strain DN11 is a denitrifying bacterium capable of benzene degradation under anaerobic conditions. The present study evaluated strain DN11 for its application to bioaugmentation of benzene-contaminated underground aquifers. Strain DN11 could grow on benzene, toluene, m-xylene, and benzoate as the sole carbon and energy sources under nitrate-reducing conditions, although o- and p-xylenes were transformed in the presence of toluene. Phenol was not utilized under anaerobic conditions. Kinetic analysis of anaerobic benzene degradation estimated its apparent affinity and inhibition constants to be 0.82 and 11 {mu}M, respectively. Benzene-contaminated groundwater taken from a former coal-distillation plant site in Aichi, Japan was anaerobically incubated in laboratory bottles and supplemented with either inorganic nutrients (nitrogen, phosphorus, and nitrate) alone, or the nutrients plus strain DN11, showing that benzene was significantly degraded only when DN11 was introduced. Denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA gene fragments, and quantitative PCR revealed that DN11 decreased after benzene was degraded. Following the decrease in DN11 16S rRNA gene fragments corresponding to bacteria related to Owenweeksia hongkongensis and Pelotomaculum isophthalicum, appeared as strong bands, suggesting possible metabolic interactions in anaerobic benzene degradation. Results suggest that DN11 is potentially useful for degrading benzene that contaminates underground aquifers at relatively low concentrations. 50 refs., 6 figs., 1 tab.

  4. Kinetic study of the anaerobic biodegradation of alkyl polyglucosides and the influence of their structural parameters.

    Science.gov (United States)

    Ríos, Francisco; Fernández-Arteaga, Alejandro; Lechuga, Manuela; Jurado, Encarnación; Fernández-Serrano, Mercedes

    2016-05-01

    This paper reports a study of the anaerobic biodegradation of non-ionic surfactants alkyl polyglucosides applying the method by measurement of the biogas production in digested sludge. Three alkyl polyglucosides with different length alkyl chain and degree of polymerization of the glucose units were tested. The influence of their structural parameters was evaluated, and the characteristics parameters of the anaerobic biodegradation were determined. Results show that alkyl polyglucosides, at the standard initial concentration of 100 mgC L(-1), are not completely biodegradable in anaerobic conditions because they inhibit the biogas production. The alkyl polyglucoside having the shortest alkyl chain showed the fastest biodegradability and reached the higher percentage of final mineralization. The anaerobic process was well adjusted to a pseudo first-order equation using the carbon produced as gas during the test; also, kinetics parameters and a global rate constant for all the involved metabolic process were determined. This modeling is helpful to evaluate the biodegradation or the persistence of alkyl polyglucosides under anaerobic conditions in the environment and in the wastewater treatment.

  5. Diversity management

    OpenAIRE

    Knákalová, Lucie

    2009-01-01

    The key topic of the work is diversity management, i.e. management of em-ployees" diversity within organization. Opening part of the work identifies the position of diversity within society and related phenomena such as stereotypes, biases and various forms of discrimination. Then the work discusses the role of diversity management in organizations, its principles and basic areas of focus. Attention is paid to certain social groups that the diversity management concept should especially deal ...

  6. VRML metabolic network visualizer.

    Science.gov (United States)

    Rojdestvenski, Igor

    2003-03-01

    A successful date collection visualization should satisfy a set of many requirements: unification of diverse data formats, support for serendipity research, support of hierarchical structures, algorithmizability, vast information density, Internet-readiness, and other. Recently, virtual reality has made significant progress in engineering, architectural design, entertainment and communication. We experiment with the possibility of using the immersive abstract three-dimensional visualizations of the metabolic networks. We present the trial Metabolic Network Visualizer software, which produces graphical representation of a metabolic network as a VRML world from a formal description written in a simple SGML-type scripting language.

  7. Anaerobic ammonia removal in presence of organic matter: A novel route

    International Nuclear Information System (INIS)

    Sabumon, P.C.

    2007-01-01

    This study describes the feasibility of anaerobic ammonia removal process in presence of organic matter. Different sources of biomass collected from diverse eco-systems containing ammonia and organic matter (OM) were screened for potential anaerobic ammonia removal. Sequential batch studies confirmed the possibility of anaerobic ammonia removal in presence of OM, but ammonia was oxidized anoxically to nitrate (at oxidation reduction potential; ORP -248 ± 25 mV) by an unknown mechanism unlike in the reported anammox process. The oxygen required for oxidation of ammonia might have been generated through catalase enzymatic activity of facultative anaerobes in mixed culture. The oxygen generation possibility by catalase enzyme route was demonstrated. Among the inorganic electron acceptors (NO 2 - , NO 3 - and SO 4 2- ) studied, NO 2 - was found to be most effective in total nitrogen removal. Denitrification by the developed culture was much effective and faster compared to ammonia oxidation. The results of this study show that anaerobic ammonia removal is feasible in presence of OM. The novel nitrogen removal route is hypothesized as enzymatic anoxic oxidation of NH 4 + to NO 3 - , followed by denitrification via autotrophic and/or heterotrophic routes. The results of batch study were confirmed in continuous reactor operation

  8. Phylogenetic and functional diversity of metagenomic libraries of phenol degrading sludge from petroleum refinery wastewater treatment system.

    Science.gov (United States)

    Silva, Cynthia C; Hayden, Helen; Sawbridge, Tim; Mele, Pauline; Kruger, Ricardo H; Rodrigues, Marili Vn; Costa, Gustavo Gl; Vidal, Ramon O; Sousa, Maíra P; Torres, Ana Paula R; Santiago, Vânia Mj; Oliveira, Valéria M

    2012-03-27

    In petrochemical refinery wastewater treatment plants (WWTP), different concentrations of pollutant compounds are received daily in the influent stream, including significant amounts of phenolic compounds, creating propitious conditions for the development of particular microorganisms that can rapidly adapt to such environment. In the present work, the microbial sludge from a refinery WWTP was enriched for phenol, cloned into fosmid vectors and pyrosequenced. The fosmid libraries yielded 13,200 clones and a comprehensive bioinformatic analysis of the sequence data set revealed a complex and diverse bacterial community in the phenol degrading sludge. The phylogenetic analyses using MEGAN in combination with RDP classifier showed a massive predominance of Proteobacteria, represented mostly by the genera Diaphorobacter, Pseudomonas, Thauera and Comamonas. The functional classification of phenol degrading sludge sequence data set generated by MG-RAST showed the wide metabolic diversity of the microbial sludge, with a high percentage of genes involved in the aerobic and anaerobic degradation of phenol and derivatives. In addition, genes related to the metabolism of many other organic and xenobiotic compounds, such as toluene, biphenyl, naphthalene and benzoate, were found. Results gathered herein demonstrated that the phenol degrading sludge has complex phylogenetic and functional diversities, showing the potential of such community to degrade several pollutant compounds. This microbiota is likely to represent a rich resource of versatile and unknown enzymes which may be exploited for biotechnological processes such as bioremediation.

  9. Versatile transformations of hydrocarbons in anaerobic bacteria: substrate ranges and regio- and stereo-chemistry of activation reactions†

    Science.gov (United States)

    Jarling, René; Kühner, Simon; Basílio Janke, Eline; Gruner, Andrea; Drozdowska, Marta; Golding, Bernard T.; Rabus, Ralf; Wilkes, Heinz

    2015-01-01

    Anaerobic metabolism of hydrocarbons proceeds either via addition to fumarate or by hydroxylation in various microorganisms, e.g., sulfate-reducing or denitrifying bacteria, which are specialized in utilizing n-alkanes or alkylbenzenes as growth substrates. General pathways for carbon assimilation and energy gain have been elucidated for a limited number of possible substrates. In this work the metabolic activity of 11 bacterial strains during anaerobic growth with crude oil was investigated and compared with the metabolite patterns appearing during anaerobic growth with more than 40 different hydrocarbons supplied as binary mixtures. We show that the range of co-metabolically formed alkyl- and arylalkyl-succinates is much broader in n-alkane than in alkylbenzene utilizers. The structures and stereochemistry of these products are resolved. Furthermore, we demonstrate that anaerobic hydroxylation of alkylbenzenes does not only occur in denitrifiers but also in sulfate reducers. We propose that these processes play a role in detoxification under conditions of solvent stress. The thermophilic sulfate-reducing strain TD3 is shown to produce n-alkylsuccinates, which are suggested not to derive from terminal activation of n-alkanes, but rather to represent intermediates of a metabolic pathway short-cutting fumarate regeneration by reverse action of succinate synthase. The outcomes of this study provide a basis for geochemically tracing such processes in natural habitats and contribute to an improved understanding of microbial activity in hydrocarbon-rich anoxic environments. PMID:26441848

  10. EFFECT OF MUSIC ON ANAEROBIC EXERCISE PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Tülin Atan

    2013-01-01

    Full Text Available 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.

  11. Imaging metabolic heterogeneity in cancer.

    Science.gov (United States)

    Sengupta, Debanti; Pratx, Guillem

    2016-01-06

    As our knowledge of cancer metabolism has increased, it has become apparent that cancer metabolic processes are extremely heterogeneous. The reasons behind this heterogeneity include genetic diversity, the existence of multiple and redundant metabolic pathways, altered microenvironmental conditions, and so on. As a result, methods in the clinic and beyond have been developed in order to image and study tumor metabolism in the in vivo and in vitro regimes. Both regimes provide unique advantages and challenges, and may be used to provide a picture of tumor metabolic heterogeneity that is spatially and temporally comprehensive. Taken together, these methods may hold the key to appropriate cancer diagnoses and treatments in the future.

  12. A simple anaerobic system for onsite treatment of domestic wastewater

    African Journals Online (AJOL)

    Among several anaerobic treatment processes, high rate anaerobic digesters receive great attention due to its high loading capacity and chemical oxygen demand removal rate. Up-flow anaerobic sludge blanket reactor (UASB) is getting wide acceptance among several anaerobic processes. However, its application is still ...

  13. Isolation of anaerobes from bubo associated with chancroid.

    Science.gov (United States)

    Kumar, B; Sharma, V K; Bakaya, V; Ayyagiri, A

    1991-01-01

    Ten men with bubo associated with chancroid were studied for bacterial flora especially anaerobes. Anaerobes were isolated from all 10 buboes and eight out of 10 ulcers of chancroid. Anaerobic cocci, B melaninogenicus and B fragilis were the most common isolates. anaerobes probably play a role in the pathogenesis of bubo in chancroid. PMID:1680792

  14. Anaerobic digestion of hog wastes

    Energy Technology Data Exchange (ETDEWEB)

    Taiganides, E P; Baumann, E R; Johnson, H P; Hazen, T E

    1963-01-01

    A short history, a list of advantages and limitations, and a short introduction to the principles of the process of anaerobic digestion are given. Six five gallon bottle digesters were daily fed hog manure, maintained at 35/sup 0/C, and constantly agitated. Satisfactory operation was assured at 3.2 g VS/l/day with a detention time of 10 days, yielding 490-643 ml gas/g VS/day with a CH/sub 4/ content of 59% (2.1 x 10/sup 7/ joules/m/sup 3/). A figure and discussion portray the interrelationships of loading rate, solids concentration and detention time. They estimate that a marginal profit might be obtained by the operation of a heated digester handling the wastes of 10,000 hogs.

  15. Anaerobic degradation of linear alkylbenzene sulfonate

    DEFF Research Database (Denmark)

    Mogensen, Anders Skibsted; Haagensen, Frank; Ahring, Birgitte Kiær

    2003-01-01

    Linear alkylbenzene sulfonate (LAS) found in wastewater is removed in the wastewater treatment facilities by sorption and aerobic biodegradation. The anaerobic digestion of sewage sludge has not been shown to contribute to the removal. The concentration of LAS based on dry matter typically...... increases during anaerobic stabilization due to transformation of easily degradable organic matter. Hence, LAS is regarded as resistant to biodegradation under anaerobic conditions. We present data from a lab-scale semi-continuously stirred tank reactor (CSTR) spiked with linear dodecylbenzene sulfonate (C...

  16. Accelerated anaerobic hydrolysis rates under a combination of intermittent aeration and anaerobic conditions

    DEFF Research Database (Denmark)

    Jensen, T. R.; Lastra Milone, T.; Petersen, G.

    2017-01-01

    Anaerobic hydrolysis in activated return sludge was investigated in laboratory scale experiments to find if intermittent aeration would accelerate anaerobic hydrolysis rates compared to anaerobic hydrolysis rates under strict anaerobic conditions. The intermittent reactors were set up in a 240 h...... for calculating hydrolysis rates based on soluble COD were compared. Two-way ANOVA with the Bonferroni post-test was performed in order to register any significant difference between reactors with intermittent aeration and strictly anaerobic conditions respectively. The experiment demonstrated a statistically...... significant difference in favor of the reactors with intermittent aeration showing a tendency towards accelerated anaerobic hydrolysis rates due to application of intermittent aeration. The conclusion of the work is thus that intermittent aeration applied in the activated return sludge process (ARP) can...

  17. Aerobic and anaerobic metabolism for the zebrafish, Danio rerio, reared under normoxic and hypoxic conditions and exposed to acute hypoxia during development Metabolismo aeróbico e anaeróbico do paulistinha Danio rerio, mantidos sob normóxia e hipóxia moderada e expostos a hipóxia aguda durante diferentes estágios de desenvolvimento

    Directory of Open Access Journals (Sweden)

    WR Barrionuevo

    2010-05-01

    Full Text Available In order to verify the influence of chronic and acute ambient oxygen levels from egg to adult stage of the zebrafish, in vivo oxygen consumption (MO2, critical tensions of oxygen (Pcrit, heart rate (fH and total body lactate concentration (Lc were determined for Danio rerio (Hamilton, 1822 raised at 28 °C under normoxic (7.5 mgO2.L-1 or 80 mm.Hg-1 and hypoxic conditions (4.3 mgO2.L-1 and exposed to acute hypoxia during different developmental stages. Our findings confirmed that very early stages do not respond effectively to ambient acute hypoxia. However, after the stage corresponding to the age of 30 days, D. rerio was able to respond to acute hypoxia through effective physiological mechanisms involving aerobic and anaerobic metabolism. Such responses were more efficient for the fishes reared under hypoxia which showed that D. rerio survival capability increased during acclimation to mild hypoxia. Measurements of body mass and length showed that moderate hypoxia did not affect growth significantly until the fish reached the stage of 60 days. Moreover, a growth delay was verified for the hypoxic-reared animals. Also, the D. rerio eggs-to-larvae survival varied from 87.7 to 62.4% in animals reared under normoxia and mild hypoxia, respectively. However, the surviving animals raised under moderated hypoxia showed a better aptitude to regulate aerobic and anaerobic capacities when exposed to acute hypoxia.A influência de diferentes níveis de oxigênio no desenvolvimento (ovos a adulto do peixe paulistinha Danio rerio (Hamilton, 1822 foi verificada por meio de medidas experimentais de consumo de oxigênio (MO2, tensões críticas de oxigênio (Pcrit, taxa de batimentos cardíacos (fH e concentração total de lactato nos tecidos (Lc, para os animais mantidos a 28 ºC sob níveis normóxicos de oxigênio (7.5 mgO2.L-1 ou 80 mmHg e hipóxicos (4.3 mgO2.L-1 e submetidos a hipóxia ambiental aguda, em diferentes estágios de desenvolvimento. Os

  18. Dynamics of pyruvate metabolism in Lactococcus lactis

    DEFF Research Database (Denmark)

    Melchiorsen, Claus Rix; Jensen, Niels B.S.; Christensen, Bjarke

    2001-01-01

    The pyruvate metabolism in the lactic acid bacterium Lactococcus lactis was studied in anaerobic cultures under transient conditions. During growth of L. lactis in continuous culture at high dilution rate, homolactic product formation was observed, i.e., lactate was produced as the major end...... product. At a lower dilution rate, the pyruvate metabolism shifted towards mixed acid-product formation where formate, acetate, and ethanol were produced in addition to lactate. The regulation of the shift in pyruvate metabolism was investigated by monitoring the dynamic behavior of L. lactis...

  19. Vitamin and amino acid auxotrophy in anaerobic consortia operating under methanogenic condition

    OpenAIRE

    Eiler, Alexander; Bertilsson, Stefan; Berry, David; Wendeberg, Anneli; Foght, Julia; Tan, Boonfei; Buck, Moritz; Hubalek, Valeria

    2017-01-01

    Syntrophy among Archaea and Bacteria facilitates the anaerobic degradation of organic compounds to CH4 and CO2. Particularly during aliphatic and aromatic hydrocarbon mineralization, as in crude oil reservoirs and petroleum contaminated sediments, metabolic interactions between obligate mutualistic microbial partners are of central importance1. Using micromanipulation combined with shotgun metagenomic approaches, we disentangled the genomes of complex consortia inside a short chain alkane deg...

  20. Vitamin and Amino Acid Auxotrophy in Anaerobic Consortia Operating under Methanogenic Conditions

    OpenAIRE

    Valerie Hubalek; Moritz Buck; BoonFei Tan; Julia Foght; Annelie Wendeberg; David Berry; Stefan Bertilsson; Alexander Eiler; Karen G. Lloyd

    2017-01-01

    ABSTRACT Syntrophy among Archaea and Bacteria facilitates the anaerobic degradation of organic compounds to CH4 and CO2. Particularly during aliphatic and aromatic hydrocarbon mineralization, as in the case of crude oil reservoirs and petroleum-contaminated sediments, metabolic interactions between obligate mutualistic microbial partners are of central importance. Using micromanipulation combined with shotgun metagenomic approaches, we describe the genomes of complex consortia within short-ch...

  1. Diversity Index

    Data.gov (United States)

    Town of Chapel Hill, North Carolina — This map service summarizes racial and ethnic diversity in the United States in 2012.The Diversity Index shows the likelihood that two persons chosen at random from...

  2. Managing Diversity.

    Science.gov (United States)

    Geber, Beverly

    1990-01-01

    Demographic trends imply that organizations must learn to manage a diverse work force. Ways to change organizational systems, structures, and practices to eliminate subtle barriers are awareness training, attitude change, and valuing diversity. (SK)

  3. Mesophilic anaerobic stabilization of sewage sludge. Mesophile anaerobe Klaerschlammstabilisierung mit aerober Folgebehandlung

    Energy Technology Data Exchange (ETDEWEB)

    Stoll, U.

    1988-01-01

    Sludges treated in two stages in experiments - 7 days of anaerobic treatment and 2 days of aerobic-thermophilic treatment - can be judged to be completely stabilized because of the stabilization parameters BOD/sub 5//COD ratio and respiratory activity. The degradation results obtained are comparable to or better than those of the 20-day digestion (reference process). For all aerobic processes under investigation a clear temperature increase in the aerobic reactor was measured because of the exothermal metabolic processes of the aerobic biocenosis. There was a temperature rise of 15/sup 0/C in the tests in the aerobic reactor even after longer digestion times of 15 and 20 days. The results of the epidemics and hygiene investigations show that a secondary aerobic-thermophilic stage after the mesophilic digestion with adequate marginal conditions - germ retention time of 23 hours in the aerobic reactor at process temperatures higher than 50/sup 0/C as well as charging in batch quantities - leads to a safe and complete decontamination. Under these process and operation conditions all salmonellae were killed and the number of the enterobacteriaceae in 1 g of sludge was always less than 1.000. (orig./EF).

  4. 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 aerotolerant Clostridium perfringens strain. A zone diameter above 27 mm was indicative of acceptable anaerobic conditions....

  5. Illumina sequencing-based analysis of a microbial community enriched under anaerobic methane oxidation condition coupled to denitrification revealed coexistence of aerobic and anaerobic methanotrophs.

    Science.gov (United States)

    Siniscalchi, Luciene Alves Batista; Leite, Laura Rabelo; Oliveira, Guilherme; Chernicharo, Carlos Augusto Lemos; de Araújo, Juliana Calabria

    2017-07-01

    Methane is produced in anaerobic environments, such as reactors used to treat wastewaters, and can be consumed by methanotrophs. The composition and structure of a microbial community enriched from anaerobic sewage sludge under methane-oxidation condition coupled to denitrification were investigated. Denaturing gradient gel electrophoresis (DGGE) analysis retrieved sequences of Methylocaldum and Chloroflexi. Deep sequencing analysis revealed a complex community that changed over time and was affected by methane concentration. Methylocaldum (8.2%), Methylosinus (2.3%), Methylomonas (0.02%), Methylacidiphilales (0.45%), Nitrospirales (0.18%), and Methanosarcinales (0.3%) were detected. Despite denitrifying conditions provided, Nitrospirales and Methanosarcinales, known to perform anaerobic methane oxidation coupled to denitrification (DAMO) process, were in very low abundance. Results demonstrated that aerobic and anaerobic methanotrophs coexisted in the reactor together with heterotrophic microorganisms, suggesting that a diverse microbial community was important to sustain methanotrophic activity. The methanogenic sludge was a good inoculum to enrich methanotrophs, and cultivation conditions play a selective role in determining community composition.

  6. Rethinking Diversity.

    Science.gov (United States)

    1996

    These three papers were presented at a symposium on rethinking diversity in human resource development (HRD) moderated by Neal Chalofsky at the 1996 conference of the Academy of Human Resource Development. "Diversity: A Double-Edged Sword" (Sally F. Angus) presents the notion of work force diversity through two differing perspectives in order to…

  7. 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

  8. PENGOLAHAN LIMBAH CAIR INDUSTRI FARMASI FORMULASI DENGAN METODE ANAEROB-AEROB DAN ANAEROB-KOAGULASI

    Directory of Open Access Journals (Sweden)

    Farida Crisnaningtyas

    2016-05-01

    Full Text Available Studi ini membahas mengenai pengolahan limbah cair industri farmasi dalam skala laboratorium dengan menggunakan konsep anaerob-kimia-fisika dan anaerob-aerob. Proses anaerob dilakukan dengan menggunakan reaktor Upflow Anaerobic Sludge Bed reactor (UASBr pada kisaran OLR (Organic Loading Rate 0,5 – 2 kg COD/m3hari, yang didahului dengan proses aklimatisasi menggunakan substrat gula. Proses anaerob mampu memberikan efisiensi penurunan COD hingga 74%. Keluaran dari proses anaerob diolah lebih lanjut dengan menggunakan dua opsi proses: (1 fisika-kimia, dan (2 aerob. Koagulan alumunium sulfat dan flokulan kationik memberikan efisiensi penurunan COD tertinggi (73% pada kecepatan putaran masing-masing 100 rpm dan 40 rpm. Uji coba aerob dilakukan pada kisaran MLSS antara 4000-5000 mg/L dan mampu memberikan efisiensi penurunan COD hingga 97%. Hasil uji coba menunjukkan bahwa efisiensi penurunan COD total yang dapat dicapai dengan menggunakan teknologi anaerob-aerob adalah 97%, sedangkan kombinasi anaerob-koagulasi-flokulasi hanya mampu menurunkan COD total sebesar 72,53%. Berdasarkan hasil tersebut, kombinasi proses anaerob-aerob merupakan teknologi yang potensial untuk diaplikasikan dalam sistem pengolahan limbah cair industri farmasi. 

  9. Simulation of the anaerobic digestion process

    Energy Technology Data Exchange (ETDEWEB)

    Maia, C A.M.

    1981-01-01

    The dynamic model of anaerobic fermentation includes an inhibition function to relate volatile acid concentration to a specific growth rate for the methane bacteria and also includes the interactions between the liquid, gaseous, and biology phases of the digester.

  10. Anaerobic Toxicity of Cationic Silver Nanoparticles

    Data.gov (United States)

    U.S. Environmental Protection Agency — Toxicity data for the impact of nano-silver on anaerobic degradation. This dataset is associated with the following publication: Gitipour, A., S. Thiel, K. Scheckel,...

  11. Solar pond for heating anaerobic digesters

    International Nuclear Information System (INIS)

    Song Kehui; Li Shensheng

    1991-10-01

    A theoretical analysis and numerical results calculated for solar pond heating anaerobic digesters in Beijing area in China are presented. The effect of temperature rise is evident and rather steady. 3 refs, 1 fig., 1 tab

  12. 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

  13. 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

  14. Anaerobic membrane bioreactor under extreme conditions (poster)

    NARCIS (Netherlands)

    Munoz Sierra, J.D.; De Kreuk, M.K.; Spanjers, H.; Van Lier, J.B.

    2013-01-01

    Membrane bioreactors ensure biomass retention by the application of micro or ultrafiltration processes. This allows operation at high sludge concentrations. Previous studies have shown that anaerobic membrane bioreactors is an efficient way to retain specialist microorganisms for treating

  15. Application of Methanobrevibacter acididurans in anaerobic digestion.

    Science.gov (United States)

    Savant, D V; Ranade, D R

    2004-01-01

    To operate anaerobic digesters successfully under acidic conditions, hydrogen utilizing methanogens which can grow efficiently at low pH and tolerate high volatile fatty acids (VFA) are desirable. An acid tolerant hydrogenotrophic methanogen viz. Methanobrevibacter acididurans isolated from slurry of an anaerobic digester running on alcohol distillery wastewater has been described earlier by this lab. This organism could grow optimally at pH 6.0. In the experiments reported herein, M. acididurans showed better methanogenesis under acidic conditions with high VFA, particularly acetate, than Methanobacterium bryantii, a common hydrogenotrophic inhabitant of anaerobic digesters. Addition of M. acididurans culture to digesting slurry of acidogenic as well as methanogenic digesters running on distillery wastewater showed increase in methane production and decrease in accumulation of volatile fatty acids. The results proved the feasibility of application of M. acididurans in anaerobic digesters.

  16. Effects of shearing on biogas production and microbial community structure during anaerobic digestion with recuperative thickening.

    Science.gov (United States)

    Yang, Shufan; Phan, Hop V; Bustamante, Heriberto; Guo, Wenshan; Ngo, Hao H; Nghiem, Long D

    2017-06-01

    Recuperative thickening can intensify anaerobic digestion to produce more biogas and potentially reduce biosolids odour. This study elucidates the effects of sludge shearing during the thickening process on the microbial community structure and its effect on biogas production. Medium shearing resulted in approximately 15% increase in biogas production. By contrast, excessive or high shearing led to a marked decrease in biogas production, possibly due to sludge disintegration and cell lysis. Microbial analysis using 16S rRNA gene amplicon sequencing showed that medium shearing increased the evenness and diversity of the microbial community in the anaerobic digester, which is consistent with the observed improved biogas production. By contrast, microbial diversity decreased under either excessive shearing or high shearing condition. In good agreement with the observed decrease in biogas production, the abundance of Bacteroidales and Syntrophobaterales (which are responsible for hydrolysis and acetogenesis) decreased due to high shearing during recuperative thickening. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  17. Fermentative hydrogen production by diverse microflora

    International Nuclear Information System (INIS)

    Baghchehsaraee, B.; Nakhla, G.; Karamanev, D.; Margaritis, A.

    2009-01-01

    'Full text': In this study of hydrogen production with activated sludge, a diverse bacterial source has been investigated and compared to microflora from anaerobic digester sludge, which is less diverse. Batch experiments were conducted at mesophilic (37 o C) and thermophilic (55 o C) temperatures. The hydrogen production yields with activated sludge at 37 o C and 55 o C were 0.25 and 0.93 mol H 2 /mol glucose, respectively. The maximum hydrogen production rates with activated sludge in both temperatures were 4.2 mL/h. Anaerobic digester sludge showed higher hydrogen production yields and rates at both mesophilic and thermophilic temperatures. The results of repeated batch experiments with activated sludge showed an increase in the hydrogen production during the consecutive batches. However, hydrogen production was not stable along the repeated batches. The observed instability was due to the formation of lactic acid and ethanol. (author)

  18. Anaerobic bacteraemia revisited: species and susceptibilities.

    Science.gov (United States)

    Ng, Lily S Y; Kwang, Lee Ling; Rao, Suma; Tan, Thean Yen

    2015-01-01

    This retrospective study was performed to evaluate the frequency of anaerobic bacteraemia over a 10-year period, and to provide updated antibiotic susceptibilities for the more clinically relevant anaerobes causing blood stream infection. Data were retrieved from the laboratory information system for the period 2003 to 2012. During this time, blood cultures were inoculated in Bactec™ Plus vials (BD, USA) and continuously monitored in the Bactec™ 9000 blood culture system (BD, USA). Anaerobic organisms were identified using commercial identification kits, predominantly API 20 A (bioMérieux, France) supplemented with Vitek ANC cards (bioMérieux, France) and AN-Ident discs (Oxoid, United Kingdom). A representative subset of isolates were retrieved from 2009 to 2011 and antimicrobial susceptibilities to penicillin, amoxicillin-clavulanate, clindamycin, imipenem, moxifloxacin, piperacillin-tazobactam and metronidazole were determined using the Etest method. Anaerobes comprised 4.1% of all positive blood culture with 727 obligate anaerobes recovered over the 10-year period, representing a positivity rate of 0.35%. The only significant change in anaerobe positivity rates occurred between 2003 and 2004, with an increase of 0.2%. The Bacteroides fragilis group (45%) were the predominant anaerobic pathogens, followed by Clostridium species (12%), Propioniobacterium species (11%) and Fusobacterium species (6%). The most active in vitro antibiotics were imipenem, piperacillin-tazobactam, amoxicillin-clavulanate and metronidazole, with susceptibilities of 95.0%, 93.3%, 90.8% and 90.8% respectively. Resistance was high to penicillin, clindamycin and moxifl oxacin. However, there were apparent differences for antibiotic susceptibilities between species. This study indicates that the anaerobes comprise a small but constant proportion of bloodstream isolates. Antibiotic resistance was high to some antibiotics, but metronidazole, the beta-lactam/beta-lactamase inhibitors and

  19. Anaerobic digester for treatment of organic waste

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, V. K. [Indian Insitute of Technology, Delhi (India)]|[ENEA, Centro Ricerche Trisaia, Matera (Italy); Fortuna, F.; Canditelli, M.; Cornacchia, G. [ENEA, Centro Ricerche Trisaia, Matera (Italy). Dipt. Ambiente; Farina, R. [ENEA, centro Ricerche ``Ezio Clementel``, Bologna (Italy). Dipt. Ambiente

    1997-09-01

    The essential features of both new and more efficient reactor systems and their appropriate applications for various organic waste management situations, description of several working plants are discussed in the present communication. It is hoped that significant development reported here would be useful in opening a new vista to the application of anaerobic biotechnology for the waste treatment of both low/high organic strength and specialized treatment for toxic substances, using appropriate anaerobic methods.

  20. Covering Materials for Anaerobic Digesters Producing Biogas

    International Nuclear Information System (INIS)

    Itodo, I. N.; Philips, T. K.

    2002-01-01

    The suitability of foam, concrete and clay soil as covering material on anaerobic digesters producing biogas was investigated using four batch-type digesters of 20 litres volume. The methane yield from the digesters was of the order: foam >control> concrete > clay soil. The digester covered with foam had the highest methane yield, best temperature control and most favourable pH conditions. It is most suitable as cover material on anaerobic digesters

  1. Anaerobic Digestion Assessment for Contingency Base Waste

    Science.gov (United States)

    2014-05-01

    heating. The use of anaerobic digestion for high solids organic waste (15 to 50 percent solids; i.e., mixed organic solids, such as food waste, manure ...but the team was not able to identify any for anaerobic digestion . One potentially widespread source is manure from ruminant organisms, such as...plug-flow digesters treating swine manure and used cooking grease. Bioresource Technology 101:4362-4370. ERDC TR-14-3 63 Lansing, S., and A.R

  2. Microbial and functional diversity of a subterrestrial high pH groundwater associated to serpentinization.

    Science.gov (United States)

    Tiago, Igor; Veríssimo, António

    2013-06-01

    Microbial and functional diversity were assessed, from a serpentinization-driven subterrestrial alkaline aquifer - Cabeço de Vide Aquifer (CVA) in Portugal. DGGE analyses revealed the presence of a stable microbial community. By 16S rRNA gene libraries and pyrosequencing analyses, a diverse bacterial composition was determined, contrasting with low archaeal diversity. Within Bacteria the majority of the populations were related to organisms or sequences affiliated to class Clostridia, but members of classes Acidobacteria, Actinobacteria, Alphaproteobacteria, Betaproteobacteria, Deinococci, Gammaproteobacteria and of the phyla Bacteroidetes, Chloroflexi and Nitrospira were also detected. Domain Archaea encompassed mainly sequences affiliated to Euryarchaeota. Only form I RuBisCO - cbbL was detected. Autotrophic carbon fixation via the rTCA, 3-HP and 3-HP/4H-B cycles could not be confirmed. The detected APS reductase alpha subunit - aprA sequences were phylogenetically related to sequences of sulfate-reducing bacteria belonging to Clostridia, and also to sequences of chemolithoautothrophic sulfur-oxidizing bacteria belonging to Betaproteobacteria. Sequences of methyl coenzyme M reductase - mcrA were phylogenetically affiliated to sequences belonging to Anaerobic Methanotroph group 1 (ANME-1). The populations found and the functional key markers detected in CVA suggest that metabolisms related to H2 , methane and/or sulfur may be the major driving forces in this environment. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  3. Decomposition of Alternative Chirality Amino Acids by Alkaliphilic Anaerobe from Owens Lake, California

    Science.gov (United States)

    Townsend, Alisa; Pikuta, Elena V.; Guisler, Melissa; Hoover, Richard B.

    2009-01-01

    The study of alkaliphilic microbial communities from anaerobic sediments of Owens and Mono Lakes in California led to the isolation of a bacterial strain capable of metabolizing amino acids with alternative chirality. According to the phylogenetic analysis, the anaerobic strain BK1 belongs to the genus Tindallia; however, despite the characteristics of other described species of this genus, the strain BK1 was able to grow on D-arginine and Dlysine. Cell morphology of this strain showed straight, motile, non-spore-forming rods with sizes 0.45 x 1.2-3 microns. Physiological characteristics of the strain showed that it is catalase negative, obligately anaerobic, mesophilic, and obligately alkaliphilic. This isolate is unable to grow at pH 7 and requires CO3 (2-) ions for growth. The strain has chemo-heterotrophic metabolism and is able to ferment various proteolysis products and some sugars. It plays the role of a primary anaerobe within the trophic chain of an anaerobic microbial community by the degradation of complex protein molecules to smaller and less energetic molecules. The new isolate requires NaCl for growth, and can grow within the range of 0.5-13 %, with the optimum at 1 % NaCl (w/v). The temperature range for the growth of the new isolate is 12-40 C with optimum at 35 C. The pH range for the growth of strain BK1 occurs between 7.8 and 11.0 with optimum at 9.5. This paper presents detailed physiological characteristics of the novel isolate from Owens Lake, a unique relic ecosystem of Astrobiological significance, and makes an accent on the ability of this strain to utilize L-amino acids.

  4. Anaerobic degradation of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA).

    Science.gov (United States)

    Finneran, K T; Lovley, D R

    2001-05-01

    The potential for anaerobic degradation of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) was investigated in laboratory incubations of sediments from a petroleum-contaminated aquifer and in aquatic sediments. The addition of humic substances (HS) stimulated the anaerobic degradation of MTBE in aquifer sediments in which Fe(III) was available as an electron acceptor. This is attributed to the fact that HS and other extracellular quinones can stimulate the activity of Fe(III)-reducing microorganisms by acting as an electron shuttle between Fe(III)-reducing microorganisms and insoluble Fe(III) oxides. MTBE was not degraded in aquifer sediments without Fe(III) and HS. [14C]-MTBE added to aquatic sediments adapted for anaerobic MTBE degradation was converted to 14CO2 in the presence or absence of HS or the HS analog, anthraquione-2,6-disulfonate. Unamended aquatic sediments produced 14CH4 as well as 14CO2 from [14C]-MTBE. The aquatic sediments also rapidly consumed TBA under anaerobic conditions and converted [14C]-TBA to 14CH4 and 14CO2. An adaptation period of ca. 250-300 days was required prior to the most rapid anaerobic MTBE degradation in both sediment types, whereas TBA was metabolized in the aquatic sediments without a lag. These results demonstrate that, under the appropriate conditions, MTBE and TBA can be degraded in the absence of oxygen. This suggests that it may be possible to design strategies for the anaerobic remediation of MTBE in petroleum-contaminated subsurface environments.

  5. Mechanism of quinolone resistance in anaerobic bacteria.

    Science.gov (United States)

    Oh, H; Edlund, C

    2003-06-01

    Several recently developed quinolones have excellent activity against a broad range of aerobic and anaerobic bacteria and are thus potential drugs for the treatment of serious anaerobic and mixed infections. Resistance to quinolones is increasing worldwide, but is still relatively infrequent among anaerobes. Two main mechanisms, alteration of target enzymes (gyrase and topoisomerase IV) caused by chromosomal mutations in encoding genes, or reduced intracellular accumulation due to increased efflux of the drug, are associated with quinolone resistance. These mechanisms have also been found in anaerobic species. High-level resistance to the newer broad-spectrum quinolones often requires stepwise mutations in target genes. The increasing emergence of resistance among anaerobes may be a consequence of previous widespread use of quinolones, which may have enriched first-step mutants in the intestinal tract. Quinolone resistance in the Bacteroides fragilis group strains is strongly correlated with amino acid substitutions at positions 82 and 86 in GyrA (equivalent to positions 83 and 87 of Escherichia coli). Several studies have indicated that B. fragilis group strains possess efflux pump systems that actively expel quinolones, leading to resistance. DNA gyrase seems also to be the primary target for quinolones in Clostridium difficile, since amino acid substitutions in GyrA and GyrB have been detected in resistant strains. To what extent other mechanisms, such as mutational events in other target genes or alterations in outer-membrane proteins, contribute to resistance among anaerobes needs to be further investigated.

  6. NMR and MALDI-TOF MS based characterization of exopolysaccharides in anaerobic microbial aggregates from full-scale reactors

    KAUST Repository

    Gonzalez-Gil, Graciela

    2015-09-22

    Anaerobic granular sludge is composed of multispecies microbial aggregates embedded in a matrix of extracellular polymeric substances (EPS). Here we characterized the chemical fingerprint of the polysaccharide fraction of EPS in anaerobic granules obtained from full-scale reactors treating different types of wastewater. Nuclear magnetic resonance (NMR) signals of the polysaccharide region from the granules were very complex, likely as a result of the diverse microbial population in the granules. Using nonmetric multidimensional scaling (NMDS), the 1H NMR signals of reference polysaccharides (gellan, xanthan, alginate) and those of the anaerobic granules revealed that there were similarities between the polysaccharides extracted from granules and the reference polysaccharide alginate. Further analysis of the exopolysaccharides from anaerobic granules, and reference polysaccharides using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) revealed that exopolysaccharides from two of the anaerobic granular sludges studied exhibited spectra similar to that of alginate. The presence of sequences related to the synthesis of alginate was confirmed in the metagenomes of the granules. Collectively these results suggest that alginate-like exopolysaccharides are constituents of the EPS matrix in anaerobic granular sludge treating different industrial wastewater. This finding expands the engineered environments where alginate has been found as EPS constituent of microbial aggregates.

  7. NMR and MALDI-TOF MS based characterization of exopolysaccharides in anaerobic microbial aggregates from full-scale reactors

    KAUST Repository

    Gonzalez-Gil, Graciela; Thomas, Ludivine; Emwas, Abdul-Hamid M.; Lens, Piet N. L.; Saikaly, Pascal

    2015-01-01

    Anaerobic granular sludge is composed of multispecies microbial aggregates embedded in a matrix of extracellular polymeric substances (EPS). Here we characterized the chemical fingerprint of the polysaccharide fraction of EPS in anaerobic granules obtained from full-scale reactors treating different types of wastewater. Nuclear magnetic resonance (NMR) signals of the polysaccharide region from the granules were very complex, likely as a result of the diverse microbial population in the granules. Using nonmetric multidimensional scaling (NMDS), the 1H NMR signals of reference polysaccharides (gellan, xanthan, alginate) and those of the anaerobic granules revealed that there were similarities between the polysaccharides extracted from granules and the reference polysaccharide alginate. Further analysis of the exopolysaccharides from anaerobic granules, and reference polysaccharides using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) revealed that exopolysaccharides from two of the anaerobic granular sludges studied exhibited spectra similar to that of alginate. The presence of sequences related to the synthesis of alginate was confirmed in the metagenomes of the granules. Collectively these results suggest that alginate-like exopolysaccharides are constituents of the EPS matrix in anaerobic granular sludge treating different industrial wastewater. This finding expands the engineered environments where alginate has been found as EPS constituent of microbial aggregates.

  8. Genome analysis of the anaerobic thermohalophilic bacterium Halothermothrix orenii.

    Directory of Open Access Journals (Sweden)

    Konstantinos Mavromatis

    Full Text Available Halothermothirx orenii is a strictly anaerobic thermohalophilic bacterium isolated from sediment of a Tunisian salt lake. It belongs to the order Halanaerobiales in the phylum Firmicutes. The complete sequence revealed that the genome consists of one circular chromosome of 2578146 bps encoding 2451 predicted genes. This is the first genome sequence of an organism belonging to the Haloanaerobiales. Features of both Gram positive and Gram negative bacteria were identified with the presence of both a sporulating mechanism typical of Firmicutes and a characteristic Gram negative lipopolysaccharide being the most prominent. Protein sequence analyses and metabolic reconstruction reveal a unique combination of strategies for thermophilic and halophilic adaptation. H. orenii can serve as a model organism for the study of the evolution of the Gram negative phenotype as well as the adaptation under thermohalophilic conditions and the development of biotechnological applications under conditions that require high temperatures and high salt concentrations.

  9. Anaerobic Degradation of Bicyclic Monoterpenes in Castellaniella defragrans

    Directory of Open Access Journals (Sweden)

    Edinson Puentes-Cala

    2018-02-01

    Full Text Available The microbial degradation pathways of bicyclic monoterpenes contain unknown enzymes for carbon–carbon cleavages. Such enzymes may also be present in the betaproteobacterium Castellaniella defragrans, a model organism to study the anaerobic monoterpene degradation. In this study, a deletion mutant strain missing the first enzyme of the monocyclic monoterpene pathway transformed cometabolically the bicyclics sabinene, 3-carene and α-pinene into several monocyclic monoterpenes and traces of cyclic monoterpene alcohols. Proteomes of cells grown on bicyclic monoterpenes resembled the proteomes of cells grown on monocyclic monoterpenes. Many transposon mutants unable to grow on bicyclic monoterpenes contained inactivated genes of the monocyclic monoterpene pathway. These observations suggest that the monocyclic degradation pathway is used to metabolize bicyclic monoterpenes. The initial step in the degradation is a decyclization (ring-opening reaction yielding monocyclic monoterpenes, which can be considered as a reverse reaction of the olefin cyclization of polyenes.

  10. Anaerobic methanotrophic communities thrive in deep submarine permafrost.

    Science.gov (United States)

    Winkel, Matthias; Mitzscherling, Julia; Overduin, Pier P; Horn, Fabian; Winterfeld, Maria; Rijkers, Ruud; Grigoriev, Mikhail N; Knoblauch, Christian; Mangelsdorf, Kai; Wagner, Dirk; Liebner, Susanne

    2018-01-22

    Thawing submarine permafrost is a source of methane to the subsurface biosphere. Methane oxidation in submarine permafrost sediments has been proposed, but the responsible microorganisms remain uncharacterized. We analyzed archaeal communities and identified distinct anaerobic methanotrophic assemblages of marine and terrestrial origin (ANME-2a/b, ANME-2d) both in frozen and completely thawed submarine permafrost sediments. Besides archaea potentially involved in anaerobic oxidation of methane (AOM) we found a large diversity of archaea mainly belonging to Bathyarchaeota, Thaumarchaeota, and Euryarchaeota. Methane concentrations and δ 13 C-methane signatures distinguish horizons of potential AOM coupled either to sulfate reduction in a sulfate-methane transition zone (SMTZ) or to the reduction of other electron acceptors, such as iron, manganese or nitrate. Analysis of functional marker genes (mcrA) and fluorescence in situ hybridization (FISH) corroborate potential activity of AOM communities in submarine permafrost sediments at low temperatures. Modeled potential AOM consumes 72-100% of submarine permafrost methane and up to 1.2 Tg of carbon per year for the total expected area of submarine permafrost. This is comparable with AOM habitats such as cold seeps. We thus propose that AOM is active where submarine permafrost thaws, which should be included in global methane budgets.

  11. Repeated pulse feeding induces functional stability in anaerobic digestion.

    Science.gov (United States)

    De Vrieze, Jo; Verstraete, Willy; Boon, Nico

    2013-07-01

    Anaerobic digestion is an environmental key technology in the future bio-based economy. To achieve functional stability, a minimal microbial community diversity is required. This microbial community should also have a certain 'elasticity', i.e. the ability to rapidly adapt to suboptimal conditions or stress. In this study it was evaluated whether a higher degree of functional stability could be achieved by changing the feeding pattern, which can change the evenness, dynamics and richness of the bacterial community. The first reactor (CSTR stable ) was fed on daily basis, whereas the second reactor (CSTR dynamic ) was fed every 2 days. Average biogas production was 0.30 l CH4 l(-1) day(-1) in both reactors, although daily variation was up to four times higher in the CSTR dynamic compared with the CSTR stable during the first 50 days. Bacterial analysis revealed that this CSTR dynamic had a two times higher degree of bacterial community dynamics. The CSTR dynamic also appeared to be more tolerant to an organic shock load of 8 g COD l(-1) and ammonium levels up to 8000 mg TAN l(-1). These results suggest that the regular application of a limited pulse of organic material and/or a variation in the substrate composition might promote higher functional stability in anaerobic digestion. © 2013 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  12. Anaerobic biodegradation of nonylphenol in river sediment under nitrate- or sulfate-reducing conditions and associated bacterial community

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhao; Yang, Yuyin; Dai, Yu; Xie, Shuguang, E-mail: xiesg@pku.edu.cn

    2015-04-09

    Highlights: • NP biodegradation can occur under both nitrate- and sulfate-reducing conditions. • Anaerobic condition affects sediment bacterial diversity during NP biodegradation. • NP-degrading bacterial community structure varies under different anaerobic conditions. - Abstract: Nonylphenol (NP) is a commonly detected pollutant in aquatic ecosystem and can be harmful to aquatic organisms. Anaerobic degradation is of great importance for the clean-up of NP in sediment. However, information on anaerobic NP biodegradation in the environment is still very limited. The present study investigated the shift in bacterial community structure associated with NP degradation in river sediment microcosms under nitrate- or sulfate-reducing conditions. Nearly 80% of NP (100 mg kg{sup −1}) could be removed under these two anaerobic conditions after 90 or 110 days’ incubation. Illumina MiSeq sequencing analysis indicated that Proteobacteria, Firmicutes, Bacteroidetes and Chloroflexi became the dominant phylum groups with NP biodegradation. The proportion of Gammaproteobacteria, Deltaproteobacteria and Choloroflexi showed a marked increase in nitrate-reducing microcosm, while Gammaproteobacteria and Firmicutes in sulfate-reducing microcosm. Moreover, sediment bacterial diversity changed with NP biodegradation, which was dependent on type of electron acceptor.

  13. Genome-scale metabolic analysis of Clostridium thermocellum for bioethanol production

    Directory of Open Access Journals (Sweden)

    Brooks J Paul

    2010-03-01

    Full Text Available Abstract Background Microorganisms possess diverse metabolic capabilities that can potentially be leveraged for efficient production of biofuels. Clostridium thermocellum (ATCC 27405 is a thermophilic anaerobe that is both cellulolytic and ethanologenic, meaning that it can directly use the plant sugar, cellulose, and biochemically convert it to ethanol. A major challenge in using microorganisms for chemical production is the need to modify the organism to increase production efficiency. The process of properly engineering an organism is typically arduous. Results Here we present a genome-scale model of C. thermocellum metabolism, iSR432, for the purpose of establishing a computational tool to study the metabolic network of C. thermocellum and facilitate efforts to engineer C. thermocellum for biofuel production. The model consists of 577 reactions involving 525 intracellular metabolites, 432 genes, and a proteomic-based representation of a cellulosome. The process of constructing this metabolic model led to suggested annotation refinements for 27 genes and identification of areas of metabolism requiring further study. The accuracy of the iSR432 model was tested using experimental growth and by-product secretion data for growth on cellobiose and fructose. Analysis using this model captures the relationship between the reduction-oxidation state of the cell and ethanol secretion and allowed for prediction of gene deletions and environmental conditions that would increase ethanol production. Conclusions By incorporating genomic sequence data, network topology, and experimental measurements of enzyme activities and metabolite fluxes, we have generated a model that is reasonably accurate at predicting the cellular phenotype of C. thermocellum and establish a strong foundation for rational strain design. In addition, we are able to draw some important conclusions regarding the underlying metabolic mechanisms for observed behaviors of C. thermocellum

  14. Influence of feed characteristics on the removal of micropollutants during the anaerobic digestion of contaminated sludge

    International Nuclear Information System (INIS)

    Barret, M.; Barcia, G. Cea; Guillon, A.; Carrere, H.; Patureau, D.

    2010-01-01

    The removal of 13 polycyclic aromatic hydrocarbons, 7 polychlorobiphenyls and nonylphenol was measured during the continuous anaerobic digestion of five different sludge samples. The reactors were fed with one of the following: primary/secondary sludge (PS/SS), thermally treated PS, cellulose-added SS, or SS augmented with dissolved and colloidal matter (DCM). These various feeding conditions induced variable levels of micropollutant bioavailability (assumed to limit their biodegradation) and overall metabolism (supposed to be linked to micropollutant metabolism throughout co-metabolism). On the one hand, overall metabolism was higher with secondary sludge than with primary and the same was observed for micropollutant removal. However, when overall metabolism was enhanced thanks to cellulose addition, a negative influence on micropollutant removal was observed. This suggests that either the co-metabolic synergy would be linked to a specific metabolism or co-metabolism was not the limiting factor in this case. On the other hand, micropollutant bioavailability was presumably diminished by thermal treatment and increased by DCM addition. In both cases, micropollutant removal was reduced. These results suggest that neither overall metabolism nor bioavailability would absolutely limit micropollutant removal. Each phenomenon might alternatively predominate depending on the feed characteristics.

  15. Identity, Diversity and Diversity Management

    DEFF Research Database (Denmark)

    Holck, Lotte; Muhr, Sara Louise; Villeseche, Florence

    2016-01-01

    – The work can encourage policy makers, diversity and HR managers to question their own practices and assumptions leading to more theoretical informed diversity management practices. Originality/value – The theoretical connections between identity and diversity literature have so far not been reviewed......The purpose of this paper is to examine the relationship between the identity and diversity literatures and discuss how a better understanding of the theoretical connections between the two informs both diversity research and diversity management practices. Design/methodology/approach – Literature...... and limitations – is crucial for successful diversity management research and practice. Research limitations/implications – The authors argue for a better understanding of differences, overlaps and limits of different identity perspectives, and for a stronger engagement with practice. Practical implications...

  16. Anaerobic Nitrogen Fixers on Mars

    Science.gov (United States)

    Lewis, B. G.

    2000-07-01

    The conversion of atmospheric nitrogen gas to the protein of living systems is an amazing process of nature. The first step in the process is biological nitrogen fixation, the transformation of N2 to NH3. The phenomenon is crucial for feeding the billions of our species on Earth. On Mars, the same process may allow us to discover how life can adapt to a hostile environment, and render it habitable. Hostile environments also exist on Earth. For example, nothing grows in coal refuse piles due to the oxidation of pyrite and marcasite to sulfuric acid. Yet, when the acidity is neutralized, alfalfa and soybean plants develop root nodules typical of symbiotic nitrogen fixation with Rhizobium species possibly living in the pyritic material. When split open, these nodules exhibited the pinkish color of leghemoglobin, a protein in the nodule protecting the active nitrogen-fixing enzyme nitrogenase against the toxic effects of oxygen. Although we have not yet obtained direct evidence of nitrogenase activity in these nodules (reduction of acetylene to ethylene, for example), these findings suggested the possibility that nitrogen fixation was taking place in this hostile, non-soil material. This immediately raises the possibility that freeliving anaerobic bacteria which fix atmospheric nitrogen on Earth, could do the same on Mars.

  17. Anaerobic digestion of cellulosic wastes

    International Nuclear Information System (INIS)

    Lee, D.D.; Donaldson, T.L.

    1985-01-01

    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

  18. Anaerobic digestion of cellulosic wastes

    International Nuclear Information System (INIS)

    Donaldson, T.L.; Lee, D.D.

    1984-01-01

    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

  19. Genome resolved analysis of a premature infant gut microbial community reveals a Varibaculum cambriense genome and a shift towards fermentation-based metabolism during the third week of life.

    Science.gov (United States)

    Brown, Christopher T; Sharon, Itai; Thomas, Brian C; Castelle, Cindy J; Morowitz, Michael J; Banfield, Jillian F

    2013-12-17

    The premature infant gut has low individual but high inter-individual microbial diversity compared with adults. Based on prior 16S rRNA gene surveys, many species from this environment are expected to be similar to those previously detected in the human microbiota. However, the level of genomic novelty and metabolic variation of strains found in the infant gut remains relatively unexplored. To study the stability and function of early microbial colonizers of the premature infant gut, nine stool samples were taken during the third week of life of a premature male infant delivered via Caesarean section. Metagenomic sequences were assembled and binned into near-complete and partial genomes, enabling strain-level genomic analysis of the microbial community.We reconstructed eleven near-complete and six partial bacterial genomes representative of the key members of the microbial community. Twelve of these genomes share >90% putative ortholog amino acid identity with reference genomes. Manual curation of the assembly of one particularly novel genome resulted in the first essentially complete genome sequence (in three pieces, the order of which could not be determined due to a repeat) for Varibaculum cambriense (strain Dora), a medically relevant species that has been implicated in abscess formation.During the period studied, the microbial community undergoes a compositional shift, in which obligate anaerobes (fermenters) overtake Escherichia coli as the most abundant species. Other species remain stable, probably due to their ability to either respire anaerobically or grow by fermentation, and their capacity to tolerate fluctuating levels of oxygen. Metabolic predictions for V. cambriense suggest that, like other members of the microbial community, this organism is able to process various sugar substrates and make use of multiple different electron acceptors during anaerobic respiration. Genome comparisons within the family Actinomycetaceae reveal important differences

  20. Anaerobic Methane-Oxidizing Microbial Community in a Coastal Marine Sediment: Anaerobic Methanotrophy Dominated by ANME-3.

    Science.gov (United States)

    Bhattarai, Susma; Cassarini, Chiara; Gonzalez-Gil, Graciela; Egger, Matthias; Slomp, Caroline P; Zhang, Yu; Esposito, Giovanni; Lens, Piet N L

    2017-10-01

    The microbial community inhabiting the shallow sulfate-methane transition zone in coastal sediments from marine Lake Grevelingen (The Netherlands) was characterized, and the ability of the microorganisms to carry out anaerobic oxidation of methane coupled to sulfate reduction was assessed in activity tests. In vitro activity tests of the sediment with methane and sulfate demonstrated sulfide production coupled to the simultaneous consumption of sulfate and methane at approximately equimolar ratios over a period of 150 days. The maximum sulfate reduction rate was 5 μmol sulfate per gram dry weight per day during the incubation period. Diverse archaeal and bacterial clades were retrieved from the sediment with the majority of them clustered with Euryarchaeota, Thaumarcheota, Bacteroidetes, and Proteobacteria. The 16S rRNA gene sequence analysis showed that the sediment from marine Lake Grevelingen contained anaerobic methanotrophic Archaea (ANME) and methanogens as archaeal clades with a role in the methane cycling. ANME at the studied site mainly belong to the ANME-3 clade. This study provides one of the few reports for the presence of ANME-3 in a shallow coastal sediment. Sulfate-reducing bacteria from Desulfobulbus clades were found among the sulfate reducers, however, with very low relative abundance. Desulfobulbus has previously been commonly found associated with ANME, whereas in our study, ANME-3 and Desulfobulbus were not observed simultaneously in clusters, suggesting the possibility of independent AOM by ANME-3.

  1. Nitrogen source effects on the denitrifying anaerobic methane oxidation culture and anaerobic ammonium oxidation bacteria enrichment process.

    Science.gov (United States)

    Fu, Liang; Ding, Jing; Lu, Yong-Ze; Ding, Zhao-Wei; Zeng, Raymond J

    2017-05-01

    The co-culture system of denitrifying anaerobic methane oxidation (DAMO) and anaerobic ammonium oxidation (Anammox) has a potential application in wastewater treatment plant. This study explored the effects of permutation and combination of nitrate, nitrite, and ammonium on the culture enrichment from freshwater sediments. The co-existence of NO 3 - , NO 2 - , and NH 4 + shortened the enrichment time from 75 to 30 days and achieved a total nitrogen removal rate of 106.5 mg/L/day on day 132. Even though ammonium addition led to Anammox bacteria increase and a higher nitrogen removal rate, DAMO bacteria still dominated in different reactors with the highest proportion of 64.7% and the maximum abundance was 3.07 ± 0.25 × 10 8 copies/L (increased by five orders of magnitude) in the nitrite reactor. DAMO bacteria showed greater diversity in the nitrate reactor, and one was similar to M. oxyfera; DAMO bacteria in the nitrite reactor were relatively unified and similar to M. sinica. Interestingly, no DAMO archaea were found in the nitrate reactor. This study will improve the understanding of the impact of nitrogen source on DAMO and Anammox co-culture enrichment.

  2. Functional bacterial and archaeal community structures of major trophic groups in a full-scale anaerobic sludge digester.

    Science.gov (United States)

    Ariesyady, Herto Dwi; Ito, Tsukasa; Okabe, Satoshi

    2007-04-01

    Functional Bacteria and Archaea community structures of a full-scale anaerobic sludge digester were investigated by using a full-cycle 16S rRNA approach followed by microautoradiography (MAR)-fluorescent in situ hybridization (FISH) technique and micromanipulation. FISH analysis with a comprehensive set of 16S and 23S rRNA-targeted oligonucleotide probes based on 16S rRNA clone libraries revealed that the Gram-positive bacteria represented by probe HGC69A-hybridized Actinobacteria (8.5+/-1.4% of total 4', 6-diamidino-2-phenylindole (DAPI)-stained cells) and probe LGC354-hybridized Firmicutes (3.8+/-0.8%) were the major phylogenetic bacterial phyla, followed by Bacteroidetes (4.0+/-1.2%) and Chloroflexi (3.7+/-0.8%). The probe MX825-hybridized Methanosaeta (7.6+/-0.8%) was the most abundant archaeal group, followed by Methanomicrobiales (2.8+/-0.6%) and Methanobacteriaceae (2.7+/-0.4%). The functional community structures (diversity and relative abundance) of major trophic groups were quantitatively analyzed by MAR-FISH. The results revealed that glucose-degrading microbial community had higher abundance (ca. 10.6+/-4.9% of total DAPI-stained cells) and diversity (at least seven phylogenetic groups) as compared with fatty acid-utilizing microbial communities, which were more specialized to a few phylogenetic groups. Despite the dominance of Betaproteobacteria, members of Chloroflexi, Smithella, Syntrophomonas and Methanosaeta groups dominated the [(14)C]glucose-, [(14)C]propionate-, [(14)C]butyrate- and [(14)C]acetate-utilizing microorganism community, and accounted for 27.7+/-4.3%, 29.6+/-7.0%, 34.5+/-7.6% and 18.2+/-9.5%, respectively. In spite of low abundance (ca. 1%), the hitherto unknown metabolic functions of Spirochaeta and candidate phylum of TM7 as well as Synergistes were found to be glucose and acetate utilization, respectively.

  3. Expanding diversity of potential bacterial partners of the methanotrophic ANME archaea using Magneto-FISH

    Science.gov (United States)

    Trembath-Reichert, E.; Green-Saxena, A.; Steele, J. A.; Orphan, V. J.

    2012-12-01

    Sulfate-coupled anaerobic oxidation of methane (AOM) in marine sediments is the major sink for methane in the oceans. This process is believed to be catalyzed by as yet uncultured syntrophic consortia of ANME archaea (affiliated with the Methanosarcinales) and sulfate-reducing bacteria belonging to the Desulfosarcina/Desulfococcus and Desulfobulbaceae. These syntrophic consortia have been described from methane-rich habitats worldwide and appear to be most concentrated in areas of high methane flux, such as cold seeps along continental margins. The extent of the diversity and ecophysiological potential of these microbial associations is still poorly constrained. In an effort to better characterize the diversity of microorganisms forming associations with different clades of methanotrophic ANME archaea (ANME-1, ANME-2a/b/c, ANME-3) and link these organisms to potentially diagnostic metabolic genes (e.g. mcrA, dsrAB, aprA), we employed a unique culture-independent whole cell capture technique which combines Fluorescence In Situ Hybridization with immuno-magnetic cell capture (Magneto-FISH). We used Magneto-FISH for targeted enrichment of specific ANME groups and their associated bacteria directly from formalin- and ethanol-fixed methane seep sediment. The identity and metabolic gene diversity of captured microorganisms were then assessed by clone library construction and sequencing. Diversity recovered from Magneto-FISH experiments using general and clade-specific ANME targeted probes show both the expected selectivity of the FISH probes (i.e. predominately ANME-2c subclade captured with an ANME-2c probe and multiple ANME groups recovered with the general probe targeting most ANME). Follow up FISH experiments were conducted to confirm physical associations between ANME and unique bacterial members (deltaproteobacteria and other non-sulfate reducing groups) that were common to multiple Magneto-FISH capture experiments. Analyses of metabolic gene diversity for archaeal

  4. Anaerobic fungi (phylum Neocallimastigomycota): advances in understanding their taxonomy, life cycle, ecology, role and biotechnological potential.

    Science.gov (United States)

    Gruninger, Robert J; Puniya, Anil K; Callaghan, Tony M; Edwards, Joan E; Youssef, Noha; Dagar, Sumit S; Fliegerova, Katerina; Griffith, Gareth W; Forster, Robert; Tsang, Adrian; McAllister, Tim; Elshahed, Mostafa S

    2014-10-01

    Anaerobic fungi (phylum Neocallimastigomycota) inhabit the gastrointestinal tract of mammalian herbivores, where they play an important role in the degradation of plant material. The Neocallimastigomycota represent the earliest diverging lineage of the zoosporic fungi; however, understanding of the relationships of the different taxa (both genera and species) within this phylum is in need of revision. Issues exist with the current approaches used for their identification and classification, and recent evidence suggests the presence of several novel taxa (potential candidate genera) that remain to be characterised. The life cycle and role of anaerobic fungi has been well characterised in the rumen, but not elsewhere in the ruminant alimentary tract. Greater understanding of the 'resistant' phase(s) of their life cycle is needed, as is study of their role and significance in other herbivores. Biotechnological application of anaerobic fungi, and their highly active cellulolytic and hemi-cellulolytic enzymes, has been a rapidly increasing area of research and development in the last decade. The move towards understanding of anaerobic fungi using -omics based (genomic, transcriptomic and proteomic) approaches is starting to yield valuable insights into the unique cellular processes, evolutionary history, metabolic capabilities and adaptations that exist within the Neocallimastigomycota. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  5. Facultative or obligate anaerobic bacteria have the potential for multimodality therapy of solid tumours.

    Science.gov (United States)

    Wei, Ming Q; Ellem, Kay A O; Dunn, Paul; West, Malcolm J; Bai, Chun Xue; Vogelstein, Bert

    2007-02-01

    Recent understanding of the unique pathology of solid tumours has shed light on the difficult and disappointing nature of their clinical treatment. All solid tumours undergo angiogenesis that results in biological changes and adaptive metabolisms, i.e. formation of defective vessels, appearance of hypoxic areas, and emergence of an heterogeneous tumour cell population. This micro-milieu provides a haven for anaerobic bacteria. The strictly anaerobic clostridia have several advantages over other facultative anaerobes such as salmonella or lactic acid-producing, Gram-positive, obligate, anaerobic bifidobacteria. Both pathogenic and non-pathogenic clostridia have been demonstrated to specifically colonise and destroy solid tumours. Early trials of non-pathogenic strains in humans had shown plausible safety. Genetic modifications and adaptation of pathogenic and non-pathogenic strains have further created improved features. However, these manipulations rarely generate strains that resulted in complete tumour control alone. Combined modalities of therapies with chemo and radiation therapies, on the other hand, often perform better, including 'cure' of solid tumours in a high percentage of animals. Considering that clostridia have unlimited capacities for genetic improvement, we predict that designer clostridia forecast a promising future for the development of potent strains for tumour destruction, incorporating mechanisms such as immunotherapy to overcome immune suppression and to elicit strong anti-tumour responses.

  6. Conversion of sulfur compounds and microbial community in anaerobic treatment of fish and pork waste.

    Science.gov (United States)

    He, Ruo; Yao, Xing-Zhi; Chen, Min; Ma, Ruo-Chan; Li, Hua-Jun; Wang, Chen; Ding, Shen-Hua

    2018-04-07

    Volatile sulfur compounds (VSCs) are not only the main source of malodor in anaerobic treatment of organic waste, but also pose a threat to human health. In this study, VSCs production and microbial community was investigated during the anaerobic degradation of fish and pork waste. The results showed that after the operation of 245 days, 94.5% and 76.2% of sulfur compounds in the fish and pork waste was converted into VSCs. Among the detected VSCs including H 2 S, carbon disulfide, methanethiol, ethanethiol, dimethyl sulfide, dimethyl disulfide and dimethyl trisulfide, methanethiol was the major component with the maximum concentration of 4.54% and 3.28% in the fish and pork waste, respectively. The conversion of sulfur compounds including total sulfur, SO 4 2- -S, S 2- , methionine and cysteine followed the first-order kinetics. Miseq sequencing analysis showed that Acinetobacter, Clostridium, Proteus, Thiobacillus, Hyphomicrobium and Pseudomonas were the main known sulfur-metabolizing microorganisms in the fish and pork waste. The C/N value had most significant influence on the microbial community in the fish and pork waste. A main conversion of sulfur compounds with CH 3 SH as the key intermediate was firstly hypothesized during the anaerobic degradation of fish and pork waste. These findings are helpful to understand the conversion of sulfur compounds and to develop techniques to control ordor pollution in the anaerobic treatment of organic waste. Copyright © 2018. Published by Elsevier Ltd.

  7. Granzyme B Disrupts Central Metabolism and Protein Synthesis in Bacteria to Promote an Immune Cell Death Program.

    Science.gov (United States)

    Dotiwala, Farokh; Sen Santara, Sumit; Binker-Cosen, Andres Ariel; Li, Bo; Chandrasekaran, Sriram; Lieberman, Judy

    2017-11-16

    Human cytotoxic lymphocytes kill intracellular microbes. The cytotoxic granule granzyme proteases released by cytotoxic lymphocytes trigger oxidative bacterial death by disrupting electron transport, generating superoxide anion and inactivating bacterial oxidative defenses. However, they also cause non-oxidative cell death because anaerobic bacteria are also killed. Here, we use differential proteomics to identify granzyme B substrates in three unrelated bacteria: Escherichia coli, Listeria monocytogenes, and Mycobacteria tuberculosis. Granzyme B cleaves a highly conserved set of proteins in all three bacteria, which function in vital biosynthetic and metabolic pathways that are critical for bacterial survival under diverse environmental conditions. Key proteins required for protein synthesis, folding, and degradation are also substrates, including multiple aminoacyl tRNA synthetases, ribosomal proteins, protein chaperones, and the Clp system. Because killer cells use a multipronged strategy to target vital pathways, bacteria may not easily become resistant to killer cell attack. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. ANAEROBIC BIOLOGICAL TREATMENT OF PRODUCED WATER; TOPICAL

    International Nuclear Information System (INIS)

    John R. Gallagher

    2001-01-01

    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

  9. 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

  10. Is anaerobic blood culture necessary? If so, who needs it?

    Science.gov (United States)

    Iwata, Kentaro; Takahashi, Miwa

    2008-07-01

    The role of anaerobic blood cultures is not validated, although they are drawn routinely. We performed a retrospective chart review at a private hospital in Japan for patients admitted between July 1, 2004 to June 30, 2005 to determine patient characteristics resulting in anaerobic blood culture. During the study period, 17,775 blood culture bottles were sent for the analysis, and 2132 bottles (12.0%) were positive for microbial growth. Bacteria were grown from 958 anaerobic bottles (44.7%), and 719 (33.7%) of those were judged to represent real infections, which accounted for 410 cases of bacteremia. Only 47 cases (11.5%) were detected by anaerobic cultures alone. Among those 47, obligate anaerobes represented 12 cases. Clinical evaluation could have predicted 7 of 12 cases of obligate anaerobic bacteremia. In the remaining 5 cases, the source of bacteremia was unclear. There were 2.7 cases of anaerobic bacteremia per 1000 blood cultures. The mortality attributable to anaerobic bacteremia was 50%. Among bacteremic cases not caused by obligate anaerobes yet diagnosed solely by anaerobic bottles, either the standard 2 sets of blood were not taken or their clinical outcomes were favorable. Anaerobic blood culture can be avoided in most cases. Anaerobic blood culture may be most helpful when (1) bacteremia because of obligate anaerobes is clinically suspected, (2) patients are severely immunocompromised, and (3) source of bacteremia is not identified by clinical evaluation.

  11. Performance of mesophilic anaerobic granules for removal of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) from aqueous solution

    International Nuclear Information System (INIS)

    An Chunjiang; He Yanling; Huang Guohe; Liu Yonghong

    2010-01-01

    The performance of mesophilic anaerobic granules to degrade octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) was investigated under various conditions. The results of batch experiments showed that anaerobic granules were capable of removing HMX from aqueous solution with high efficiency. Both biotic and abiotic mechanisms contributed to the removal of HMX by anaerobic granules under mesophilic conditions. Adsorption appeared to play a significant role in the abiotic process. Furthermore, HMX could be biodegraded by anaerobic granules as the sole substrate. After 16 days of incubation, 99.04% and 96.42% of total HMX could be removed by 1 g VSS/L acclimated and unacclimated granules, respectively. Vancomycin, an inhibitor of acetogenic bacteria, caused a significant inhibition of HMX biotransformation, while 2-bromoethanesulfonic acid, an inhibitor of methanogenic bacteria, only resulted in a slight decrease of metabolic activity. The presence of the glucose, as a suitable electron donor and carbon source, was found to enhance the degradation of HMX by anaerobic granules. Our study showed that sulfate had little adverse effects on biotransformation of HMX by anaerobic granules. However, nitrate had significant inhibitory effect on the extent of HMX removal especially in the initial period. This study offered good prospects of using high-rate anaerobic technology in the treatment of munition wastewater.

  12. Diversity Management

    DEFF Research Database (Denmark)

    Ravazzani, Silvia

    2018-01-01

    This entry provides an overview of diversity management which, in the context of organizations, consists in the strategic process of harnessing the potential of all employees to create an inclusive environment and, at the same time, contribute to meeting organizational goals. The entry first...... describes the complex construct of diversity that has been variously conceptualized in the literature, embracing multiple social and informational diversity dimensions such as gender, age, culture, values, and workstyle. This is followed by illustration of the historical development of diversity-management...... discourse and practice, and possible overarching approaches guiding organizations. It goes on to elucidate elements linked to the implementation of diversity management: positive and negative outcomes, most spread practices including communication, and contingency factors shaping the understanding...

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

    Science.gov (United States)

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

    2017-08-15

    are under aerobic conditions. Under anaerobic conditions, E. coli cells accumulate excess intracellular copper, which specifically targets iron-sulfur proteins by blocking iron-sulfur cluster biogenesis. Since iron-sulfur proteins are involved in diverse and vital physiological processes, inhibition of iron-sulfur cluster biogenesis by copper disrupts multiple cellular functions and ultimately inhibits cell growth. The results from this study illustrate a new interplay between intracellular copper toxicity and iron-sulfur cluster biogenesis in bacterial cells under anaerobic conditions. Copyright © 2017 American Society for Microbiology.

  14. High frequency of phylogenetically diverse reductive dehalogenase-homologous genes in deep subseafloor sedimentary metagenomes

    Directory of Open Access Journals (Sweden)

    Mikihiko eKawai

    2014-03-01

    Full Text Available Marine subsurface sediments on the Pacific margin harbor diverse microbial communities even at depths of several hundreds meters below the seafloor (mbsf or more. Previous PCR-based molecular analysis showed the presence of diverse reductive dehalogenase gene (rdhA homologs in marine subsurface sediment, suggesting that anaerobic respiration of organohalides is one of the possible energy-yielding pathways in the organic-rich sedimentary habitat. However, primer-independent molecular characterization of rdhA has remained to be demonstrated. Here, we studied the diversity and frequency of rdhA homologs by metagenomic analysis of five different depth horizons (0.8, 5.1, 18.6, 48.5 and 107.0 mbsf at Site C9001 off the Shimokita Peninsula of Japan. From all metagenomic pools, remarkably diverse rdhA-homologous sequences, some of which are affiliated with novel clusters, were observed with high frequency. As a comparison, we also examined frequency of dissimilatory sulfite reductase genes (dsrAB, key functional genes for microbial sulfate reduction. The dsrAB were also widely observed in the metagenomic pools whereas the frequency of dsrAB genes was generally smaller than that of rdhA-homologous genes. The phylogenetic composition of rdhA-homologous genes was similar among the five depth horizons. Our metagenomic data revealed that subseafloor rdhA homologs are more diverse than previously identified from PCR-based molecular studies. Spatial distribution of similar rdhA homologs across wide depositional ages indicates that the heterotrophic metabolic processes mediated by the genes can be ecologically important, functioning in the organic-rich subseafloor sedimentary biosphere.

  15. Impact of acclimation methods on microbial communities and performance of anaerobic fluidized bed membrane bioreactors

    KAUST Repository

    Labarge, Nicole

    2016-10-17

    An anaerobic fluidized bed membrane bioreactor (AFMBR) is a new and effective method for energy-efficient treatment of low strength wastewater, but the factors that affect performance are not well known. Different inocula and acclimation methods of the granular activated carbon (GAC) used in the reactor were examined here to determine their impact on chemical oxygen demand (COD) removal and microbial community composition of domestic wastewater-fed AFMBRs. AFMBRs inoculated with anaerobic digester sludge (D) or domestic wastewater (W) and fed domestic wastewater, or inoculated with a microbiologically diverse anaerobic bog sediment and acclimated using methanol (M), all produced the same COD removal of 63 ± 12% using a diluted wastewater feed (100 ± 21 mg L−1 COD). However, an AFMBR with GAC inoculated with anaerobic digester sludge and acclimated using acetate (A) showed significantly increased wastewater COD removal to 84 ± 6%. In addition, feeding the AFMBR with the M-acclimated GAC with an acetate medium for one week subsequently increased COD removal to 70 ± 6%. Microbial communities enriched on the GAC included Geobacter, sulfur-reducing bacteria, Syntrophaceae, and Chlorobiaceae, with reactor A having the highest relative abundance of Geobacter. These results showed that acetate was the most useful substrate for acclimation of GAC communities, and GAC harbors unique communities relative to those in the AFMBR influent and recirculated solution.

  16. Anaerobic oral flora in the North American black bear (Ursus americanus) in eastern North Carolina.

    Science.gov (United States)

    Clarke, Elsburgh O; Stoskopf, Michael K; Minter, Larry J; Stringer, Elizabeth M

    2012-06-01

    Microbial flora can provide insight into the ecology and natural history of wildlife in addition to improving understanding of health risks. This study examines the anaerobic oral flora of hunter killed black bears (Ursus americanus) in eastern North Carolina. Oral swabs from the buccal and lingual supragingival tooth surfaces of the first and second mandibular and maxillary molars of 22 black bears were inoculated onto Brucella Blood Agar plates supplemented with hemin and vitamin K after transport from the field using reduced oxoid nutrient broth. Sixteen anaerobic bacterial species, representing nine genera were identified using the RapID ANA II Micromethod Kit system and a number of organisms grown that could not be identified with the system. The most frequently identified anaerobes were Peptostreptococcus prevotii, Streptococcus constellatus, and Porphyromonas gingivalis. The diversity in the anaerobic oral flora of black bear in eastern North Carolina suggests the importance of including these organisms in basic health risk assessment protocols and suggests a potential tool for assessment of bear/habitat interactions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Long-term performance of anaerobic digestion for crop residues containing heavy metals and response of microbial communities.

    Science.gov (United States)

    Lee, Jongkeun; Kim, Joonrae Roger; Jeong, Seulki; Cho, Jinwoo; Kim, Jae Young

    2017-01-01

    In order to investigate the long-term stability on the performance of the anaerobic digestion process, a laboratory-scale continuous stirred-tank reactor (CSTR) was operated for 1100 days with sunflower harvested in a heavy metal contaminated site. Changes of microbial communities during digestion were identified using pyrosequencing. According to the results, soluble heavy metal concentrations were lower than the reported inhibitory level and the reactor performance remained stable up to OLR of 2.0g-VS/L/day at HRT of 20days. Microbial communities commonly found in anaerobic digestion for cellulosic biomass were observed and stably established with respect to the substrate. Thus, the balance of microbial metabolism was maintained appropriately and anaerobic digestion seems to be feasible for disposal of heavy metal-containing crop residues from phytoremediation sites. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. The cross-tissue metabolic response of abalone (Haliotis midae) to functional hypoxia.

    Science.gov (United States)

    Venter, Leonie; Loots, Du Toit; Mienie, Lodewyk J; Jansen van Rensburg, Peet J; Mason, Shayne; Vosloo, Andre; Lindeque, Jeremie Z

    2018-03-23

    Functional hypoxia is a stress condition caused by the abalone itself as a result of increased muscle activity, which generally necessitates the employment of anaerobic metabolism if the activity is sustained for prolonged periods. With that being said, abalone are highly reliant on anaerobic metabolism to provide partial compensation for energy production during oxygen-deprived episodes. However, current knowledge on the holistic metabolic response for energy metabolism during functional hypoxia, and the contribution of different metabolic pathways and various abalone tissues towards the overall accumulation of anaerobic end-products in abalone are scarce. Metabolomics analysis of adductor muscle, foot muscle, left gill, right gill, haemolymph and epipodial tissue samples indicated that South African abalone ( Haliotis midae) subjected to functional hypoxia utilises predominantly anaerobic metabolism, and depends on all of the main metabolite classes (proteins, carbohydrates and lipids) for energy supply. Functional hypoxia caused increased levels of anaerobic end-products: lactate, alanopine, tauropine, succinate and alanine. Also, elevation in arginine levels was detected, confirming that abalone use phosphoarginine to generate energy during functional hypoxia. Different tissues showed varied metabolic responses to hypoxia, with functional hypoxia showing excessive changes in the adductor muscle and gills. From this metabolomics investigation, it becomes evident that abalone are metabolically able to produce sufficient amounts of energy when functional hypoxia is experienced. Also, tissue interplay enables the adjustment of H. midae energy requirements as their metabolism shifts from aerobic to anaerobic respiration during functional hypoxia.This article has an associated First Person interview with the first author of the paper. © 2018. Published by The Company of Biologists Ltd.

  19. The cross-tissue metabolic response of abalone (Haliotis midae to functional hypoxia

    Directory of Open Access Journals (Sweden)

    Leonie Venter

    2018-03-01

    Full Text Available Functional hypoxia is a stress condition caused by the abalone itself as a result of increased muscle activity, which generally necessitates the employment of anaerobic metabolism if the activity is sustained for prolonged periods. With that being said, abalone are highly reliant on anaerobic metabolism to provide partial compensation for energy production during oxygen-deprived episodes. However, current knowledge on the holistic metabolic response for energy metabolism during functional hypoxia, and the contribution of different metabolic pathways and various abalone tissues towards the overall accumulation of anaerobic end-products in abalone are scarce. Metabolomics analysis of adductor muscle, foot muscle, left gill, right gill, haemolymph and epipodial tissue samples indicated that South African abalone (Haliotis midae subjected to functional hypoxia utilises predominantly anaerobic metabolism, and depends on all of the main metabolite classes (proteins, carbohydrates and lipids for energy supply. Functional hypoxia caused increased levels of anaerobic end-products: lactate, alanopine, tauropine, succinate and alanine. Also, elevation in arginine levels was detected, confirming that abalone use phosphoarginine to generate energy during functional hypoxia. Different tissues showed varied metabolic responses to hypoxia, with functional hypoxia showing excessive changes in the adductor muscle and gills. From this metabolomics investigation, it becomes evident that abalone are metabolically able to produce sufficient amounts of energy when functional hypoxia is experienced. Also, tissue interplay enables the adjustment of H. midae energy requirements as their metabolism shifts from aerobic to anaerobic respiration during functional hypoxia. This article has an associated First Person interview with the first author of the paper.

  20. Methane-yielding microbial communities processing lactate-rich substrates: a piece of the anaerobic digestion puzzle.

    Science.gov (United States)

    Detman, Anna; Mielecki, Damian; Pleśniak, Łukasz; Bucha, Michał; Janiga, Marek; Matyasik, Irena; Chojnacka, Aleksandra; Jędrysek, Mariusz-Orion; Błaszczyk, Mieczysław K; Sikora, Anna

    2018-01-01

    Anaerobic digestion, whose final products are methane and carbon dioxide, ensures energy flow and circulation of matter in ecosystems. This naturally occurring process is used for the production of renewable energy from biomass. Lactate, a common product of acidic fermentation, is a key intermediate in anaerobic digestion of biomass in the environment and biogas plants. Effective utilization of lactate has been observed in many experimental approaches used to study anaerobic digestion. Interestingly, anaerobic lactate oxidation and lactate oxidizers as a physiological group in methane-yielding microbial communities have not received enough attention in the context of the acetogenic step of anaerobic digestion. This study focuses on metabolic transformation of lactate during the acetogenic and methanogenic steps of anaerobic digestion in methane-yielding bioreactors. Methane-yielding microbial communities instead of pure cultures of acetate producers were used to process artificial lactate-rich media to methane and carbon dioxide in up-flow anaerobic sludge blanket reactors. The media imitated the mixture of acidic products found in anaerobic environments/digesters where lactate fermentation dominates in acidogenesis. Effective utilization of lactate and biogas production was observed. 16S rRNA profiling was used to examine the selected methane-yielding communities. Among Archaea present in the bioreactors, the order Methanosarcinales predominated. The acetoclastic pathway of methane formation was further confirmed by analysis of the stable carbon isotope composition of methane and carbon dioxide. The domain Bacteria was represented by Bacteroidetes , Firmicutes , Proteobacteria , Synergistetes , Actinobacteria , Spirochaetes , Tenericutes , Caldithrix , Verrucomicrobia , Thermotogae , Chloroflexi , Nitrospirae, and Cyanobacteria. Available genome sequences of species and/or genera identified in the microbial communities were searched for genes encoding the lactate

  1. Cancer Cell Metabolism: One Hallmark, Many Faces

    OpenAIRE

    Cantor, Jason R.; Sabatini, David M.

    2012-01-01

    Cancer cells must rewire cellular metabolism to satisfy the demands of growth and proliferation. Although many of the metabolic alterations are largely similar to those in normal proliferating cells, they are aberrantly driven in cancer by a combination of genetic lesions and nongenetic factors such as the tumor microenvironment. However, a single model of altered tumor metabolism does not describe the sum of metabolic changes that can support cell growth. Instead, the