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Sample records for aerobic microbial enhanced

  1. Aerobic microbial enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Torsvik, T. [Univ. of Bergen (Norway); Gilje, E.; Sunde, E.

    1995-12-31

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

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

    Science.gov (United States)

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

    2006-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, V.; Wang, Xiao-Hui; Tay, S.T.L.; Tay, Joo-Hwa [Nanyang Technological Univ., Singapore (Singapore). School of Civil and Environmental Engineering

    2006-04-15

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

  4. Dynamics of Microbial Community Structure of and Enhanced Biological Phosphorus Removal by Aerobic Granules Cultivated on Propionate or Acetate▿

    OpenAIRE

    Gonzalez-Gil, Graciela; Holliger, Christof

    2011-01-01

    Aerobic granules are dense microbial aggregates with the potential to replace floccular sludge for the treatment of wastewaters. In bubble-column sequencing batch reactors, distinct microbial populations dominated propionate- and acetate-cultivated aerobic granules after 50 days of reactor operation when only carbon removal was detected. Propionate granules were dominated by Zoogloea (40%), Acidovorax, and Thiothrix, whereas acetate granules were mainly dominated by Thiothrix (60%). Thereafte...

  5. Microbial community structure in a thermophilic aerobic digester used as a sludge pretreatment process for the mesophilic anaerobic digestion and the enhancement of methane production.

    Science.gov (United States)

    Jang, Hyun Min; Park, Sang Kyu; Ha, Jeong Hyub; Park, Jong Moon

    2013-10-01

    An effective two-stage sewage sludge digestion process, consisting of thermophilic aerobic digestion (TAD) followed by mesophilic anaerobic digestion (MAD), was developed for efficient sludge reduction and methane production. Using TAD as a biological pretreatment, the total volatile suspended solid reduction (VSSR) and methane production rate (MPR) in the MAD reactor were significantly improved. According to denaturing gradient gel electrophoresis (DGGE) analysis, the results indicated that the dominant bacteria species such as Ureibacillus thermophiles and Bacterium thermus in TAD were major routes for enhancing soluble organic matter. TAD pretreatment using a relatively short SRT of 1 day showed highly increased soluble organic products and positively affected an increment of bacteria populations which performed interrelated microbial metabolisms with methanogenic species in the MAD; consequently, a quantitative real-time PCR indicated greatly increased Methanosarcinales (acetate-utilizing methanogens) in the MAD, resulting in enhanced methane production. PMID:23419990

  6. Nitrogen removal characteristics of indigenous aerobic denitrifiers and changes in the microbial community of a reservoir enclosure system via in situ oxygen enhancement using water lifting and aeration technology.

    Science.gov (United States)

    Zhou, Shilei; Huang, Tinglin; Ngo, Huu Hao; Zhang, Haihan; Liu, Fei; Zeng, Mingzheng; Shi, Jianchao; Qiu, Xiaopeng

    2016-08-01

    Indigenous aerobic denitrifiers of a reservoir system were enhanced in situ by water lifting and aeration technology. Nitrogen removal characteristics and changes in the bacterial community were investigated. Results from a 30-day experiment showed that the TN in the enhanced water system decreased from 1.08-2.02 to 0.75-0.91mg/L and that TN removal rates varied between 21.74% and 52.54% without nitrite accumulation, and TN removal rate of surface sediments reached 41.37±1.55%. The densities of aerobic denitrifiers in the enhanced system increased. Furthermore, the enhanced system showed a clear inhibition of Fe, Mn, and P performances. Community analysis using Miseq showed that diversity was higher in the in situ oxygen enhanced system than in the control system. In addition, the microbial composition was significantly different between systems. It can be concluded that in situ enhancement of indigenous aerobic denitrifiers is very effective in removing nitrogen from water reservoir systems. PMID:27128190

  7. Aerobic Microbial Respiration In Oceanic Oxygen Minimum Zones

    DEFF Research Database (Denmark)

    Kalvelage, Tim; Lavik, Gaute; Jensen, Marlene Mark;

    2015-01-01

    Namibia and Peru. Experiments with additions of double-labelled oxygen revealed high aerobic activity in the upper OMZs, likely controlled by surface organic matter export. Consistently observed oxygen consumption in samples retrieved throughout the lower OMZs hints at efficient exploitation of vertically...... denitrification and alternative anaerobic pathways of organic matter remineralization cannot account for the ammonium requirements of reported anammox rates. Here, we explore the significance of microaerobic respiration as a source of ammonium during organic matter degradation in the oxygen-deficient waters off...... and laterally advected, oxygenated waters in this zone by aerobic microorganisms. In accordance, metagenomic and metatranscriptomic analyses identified genes encoding for aerobic terminal oxidases and demonstrated their expression by diverse microbial communities, even in virtually anoxic waters. Our...

  8. Aerobic Microbial Skin Flora in Jeddah City, Saudi Arabia

    OpenAIRE

    Rajaa M. Milyani

    2001-01-01

    The aerobic microbial skin flora of 40 healthy subjects living in Jeddah city (Saudi Arabia) was determined. Two age groups: children and adults; including males and females were investigated. Seven sites were studied: forehead, axilla, chest, groin, leg, toe web and anterior nares. The skin was sampled by rubbing the chosen site with a surfactant substance (Tween 80) moistened cotton swab which was dipped back in the surfactant container and the resulted suspension was agitated for one minut...

  9. Aerobic Microbial Respiration In Oceanic Oxygen Minimum Zones

    DEFF Research Database (Denmark)

    Kalvelage, Tim; Lavik, Gaute; Jensen, Marlene Mark;

    2015-01-01

    denitrification and alternative anaerobic pathways of organic matter remineralization cannot account for the ammonium requirements of reported anammox rates. Here, we explore the significance of microaerobic respiration as a source of ammonium during organic matter degradation in the oxygen-deficient waters off...... and laterally advected, oxygenated waters in this zone by aerobic microorganisms. In accordance, metagenomic and metatranscriptomic analyses identified genes encoding for aerobic terminal oxidases and demonstrated their expression by diverse microbial communities, even in virtually anoxic waters. Our......Oxygen minimum zones are major sites of fixed nitrogen loss in the ocean. Recent studies have highlighted the importance of anaerobic ammonium oxidation, anammox, in pelagic nitrogen removal. Sources of ammonium for the anammox reaction, however, remain controversial, as heterotrophic...

  10. Enhancement of aerobic granulation by zero-valent iron in sequencing batch airlift reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Qiang, E-mail: kongqiang0531@hotmail.com [College of Life Science, Shandong Normal University, 88 Wenhua Donglu, Jinan 250014, Shandong (China); Ngo, Huu Hao [School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007 (Australia); Shu, Li [School of Engineering, Faculty of Science, Engineering and Built Environment, Deakin University, Geelong, Victoria 3216 (Australia); Fu, Rong-shu; Jiang, Chun-hui [College of Life Science, Shandong Normal University, 88 Wenhua Donglu, Jinan 250014, Shandong (China); Miao, Ming-sheng, E-mail: mingshengmiao@163.com [College of Life Science, Shandong Normal University, 88 Wenhua Donglu, Jinan 250014, Shandong (China)

    2014-08-30

    Highlights: • Zero-valent iron (ZVI) was used firstly to enhance the aerobic granulation. • ZVI significantly decreased the start-up time of the aerobic granulation. • ZVI had the function of enhancing organic material diversity identified by 3-D EEM. • ZVI could enhance the diversity of microbial community. - Abstract: This study elucidates the enhancement of aerobic granulation by zero-valent iron (ZVI). A reactor augmented with ZVI had a start-up time of aerobic granulation (43 days) that was notably less than that for a reactor without augmentation (64 days). The former reactor also had better removal efficiencies for chemical oxygen demand and ammonium. Moreover, the mature granules augmented with ZVI had better physical characteristics and produced more extracellular polymeric substances (especially of protein). Three-dimensional-excitation emission matrix fluorescence showed that ZVI enhanced organic material diversity. Additionally, ZVI enhanced the diversity of the microbial community. Fe{sup 2+} dissolution from ZVI helped reduce the start-up time of aerobic granulation and increased the extracellular polymeric substance content. Conclusively, the use of ZVI effectively enhanced aerobic granulation.

  11. Enhancement of aerobic granulation by zero-valent iron in sequencing batch airlift reactor

    International Nuclear Information System (INIS)

    Highlights: • Zero-valent iron (ZVI) was used firstly to enhance the aerobic granulation. • ZVI significantly decreased the start-up time of the aerobic granulation. • ZVI had the function of enhancing organic material diversity identified by 3-D EEM. • ZVI could enhance the diversity of microbial community. - Abstract: This study elucidates the enhancement of aerobic granulation by zero-valent iron (ZVI). A reactor augmented with ZVI had a start-up time of aerobic granulation (43 days) that was notably less than that for a reactor without augmentation (64 days). The former reactor also had better removal efficiencies for chemical oxygen demand and ammonium. Moreover, the mature granules augmented with ZVI had better physical characteristics and produced more extracellular polymeric substances (especially of protein). Three-dimensional-excitation emission matrix fluorescence showed that ZVI enhanced organic material diversity. Additionally, ZVI enhanced the diversity of the microbial community. Fe2+ dissolution from ZVI helped reduce the start-up time of aerobic granulation and increased the extracellular polymeric substance content. Conclusively, the use of ZVI effectively enhanced aerobic granulation

  12. Aerobic granules: microbial landscape and architecture, stages, and practical implications.

    Science.gov (United States)

    Gonzalez-Gil, Graciela; Holliger, Christof

    2014-06-01

    For the successful application of aerobic granules in wastewater treatment, granules containing an appropriate microbial assembly able to remove contaminants should be retained and propagated within the reactor. To manipulate and/or optimize this process, a good understanding of the formation and dynamic architecture of the granules is desirable. Models of granules often assume a spherical shape with an outer layer and an inner core, but limited information is available regarding the extent of deviations from such assumptions. We report on new imaging approaches to gain detailed insights into the structural characteristics of aerobic granules. Our approach stained all components of the granule to obtain a high quality contrast in the images; hence limitations due to thresholding in the image analysis were overcome. A three-dimensional reconstruction of the granular structure was obtained that revealed the mesoscopic impression of the cavernlike interior of the structure, showing channels and dead-end paths in detail. In "old" granules, large cavities allowed for the irrigation and growth of dense microbial colonies along the path of the channels. Hence, in some areas, paradoxically higher biomass content was observed in the inner part of the granule compared to the outer part. Microbial clusters "rooting" from the interior of the mature granule structure indicate that granules mainly grow via biomass outgrowth and not by aggregation of small particles. We identify and discuss phenomena contributing to the life cycle of aerobic granules. With our approach, volumetric tetrahedral grids are generated that may be used to validate complex models of granule formation. PMID:24657859

  13. Aerobic microbial metabolism of condensed thiophenes found in petroleum

    International Nuclear Information System (INIS)

    The aerobic microbial degradation of 21 condensed thiophenes found in petroleum or synthetic fuels have been studied, motivated by recent research which showed that resistance to biodegradation increases with increasing methyl-substitution. The specific objective was to identify metabolites in pure cultures of aromatic hydrocarbon-degrading Pseudomonas spp. incubated in mineral medium in the presence of an aromatic growth substrate and a condensed thiophene. Over 80 metabolites of the condensed thiophenes were identified using gas chromatography analysis with an atomic emission detector. Among the metabolites identified were sulfoxides, sulfones, hydroxy- and carboxyl-substituted benzothiophenes, hydroxy-substituted dibenzothiophenes, substituted benzothiophene-2,3-diones, and 3-hydroxy-2-formylbenzothiophenes

  14. Enhancement of aerobic granulation by zero-valent iron in sequencing batch airlift reactor.

    Science.gov (United States)

    Kong, Qiang; Ngo, Huu Hao; Shu, Li; Fu, Rong-Shu; Jiang, Chun-Hui; Miao, Ming-sheng

    2014-08-30

    This study elucidates the enhancement of aerobic granulation by zero-valent iron (ZVI). A reactor augmented with ZVI had a start-up time of aerobic granulation (43 days) that was notably less than that for a reactor without augmentation (64 days). The former reactor also had better removal efficiencies for chemical oxygen demand and ammonium. Moreover, the mature granules augmented with ZVI had better physical characteristics and produced more extracellular polymeric substances (especially of protein). Three-dimensional-excitation emission matrix fluorescence showed that ZVI enhanced organic material diversity. Additionally, ZVI enhanced the diversity of the microbial community. Fe(2+) dissolution from ZVI helped reduce the start-up time of aerobic granulation and increased the extracellular polymeric substance content. Conclusively, the use of ZVI effectively enhanced aerobic granulation. PMID:25108827

  15. Microbial fuel cells with highly active aerobic biocathodes

    Science.gov (United States)

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

    2016-08-01

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

  16. Aerobic Microbial Respiration In Oceanic Oxygen Minimum Zones.

    Directory of Open Access Journals (Sweden)

    Tim Kalvelage

    Full Text Available Oxygen minimum zones are major sites of fixed nitrogen loss in the ocean. Recent studies have highlighted the importance of anaerobic ammonium oxidation, anammox, in pelagic nitrogen removal. Sources of ammonium for the anammox reaction, however, remain controversial, as heterotrophic denitrification and alternative anaerobic pathways of organic matter remineralization cannot account for the ammonium requirements of reported anammox rates. Here, we explore the significance of microaerobic respiration as a source of ammonium during organic matter degradation in the oxygen-deficient waters off Namibia and Peru. Experiments with additions of double-labelled oxygen revealed high aerobic activity in the upper OMZs, likely controlled by surface organic matter export. Consistently observed oxygen consumption in samples retrieved throughout the lower OMZs hints at efficient exploitation of vertically and laterally advected, oxygenated waters in this zone by aerobic microorganisms. In accordance, metagenomic and metatranscriptomic analyses identified genes encoding for aerobic terminal oxidases and demonstrated their expression by diverse microbial communities, even in virtually anoxic waters. Our results suggest that microaerobic respiration is a major mode of organic matter remineralization and source of ammonium (~45-100% in the upper oxygen minimum zones, and reconcile hitherto observed mismatches between ammonium producing and consuming processes therein.

  17. Formation and functions of aerobic microbial granula; Entstehung und Funktionen aerober mikrobieller Granula

    Energy Technology Data Exchange (ETDEWEB)

    Etterer, T.; Wilderer, P.A. [Technische Univ. Muenchen, Garching (Germany). Lehrstuhl und Pruefamt fuer Wasserguete- und Abfallwirtschaft

    1999-07-01

    The present project investigates the phenomenon of the formation of aerobic microbial granula and their properties. To generate granula, sequencing batch reactors fed in batches were used. As shown by microbiological assays, fungi played an above-average role in granula formation and build-up. In first degradation experiments, furthermore, chemical oxygen demand (COD) could be reduced by over 90 %. The determination yielded comparable values to activated sludge, standing on average at 1.044g/ml. (orig.) [German] Im Rahmen des hier vorgestellten Projekts wurde das Phaenomen der Bildung aerober mikrobieller Granula sowie deren Eigenschaften untersucht. Zur Erzeugung von Granula wurden schubweise beschickte Reaktoren, sogenannte Sequencing-Batch-Reaktoren (SBR) verwendet. Wie mikrobiologische Untersuchungen zeigten spielen Pilze bei der Entstehung und beim Aufbau eine ueberdurchschnittliche Rolle. Des weiteren konnte in ersten Abbauversuchen der chemische Sauerstoff-Bedarf (CSB) um ueber 90% gesenkt werden. Die Dichtebestimmung ergab vergleichbare Werte zu Belebtschlamm und zwar im Durchschnitt 1,044 g/ml. (orig.)

  18. EVALUATION OF A TWO-STAGE TREATMENT OF DOMESTIC SEWAGE WITH ANAEROBIC-AEROBIC MICROBIAL FILM

    OpenAIRE

    A.Mesdaghinia

    1986-01-01

    The objective of this research was to study the feasibility of a two stage continuous system employing anaerobic-aerobic microbial film for domestic wastewater treatment and the effect of iron on the behavior of sulfate reducing bacteria in anaerobic metabolism. A bench scale system with an anaerobic filter followed by aerobic fixed units used plastic media and was operated in up flow manner with hydraulic detention times of 6 hours, whereas the aerobic unit utilized diffused aeration. Raw do...

  19. Aerobic Microbial Skin Flora in Jeddah City, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Rajaa M. Milyani

    2001-12-01

    Full Text Available The aerobic microbial skin flora of 40 healthy subjects living in Jeddah city (Saudi Arabia was determined. Two age groups: children and adults; including males and females were investigated. Seven sites were studied: forehead, axilla, chest, groin, leg, toe web and anterior nares. The skin was sampled by rubbing the chosen site with a surfactant substance (Tween 80 moistened cotton swab which was dipped back in the surfactant container and the resulted suspension was agitated for one minute. Thirty three microbial species were isolated from the seven sites of the study group, in which Acinetobacter baumannii, Acinetobacter lwoffii, corynebacterium species and Staphylococcus (Staph. aureus dominated among children (30% each. The most other prevalent isolates recovered were Alkaligenes species, Bacillus species, Chryseomonas luteola, Staph. epidermidis, Enterococcus faecalis and Staph. hominis (27.5% each. Organisms including Candida albicans, Enterobacter agglomerans, Escherichia coli, Flavobacterium meningosepticum, Klebsiella oxytoca, Micrococcus luteus, Micrococcus roseus, Micrococcus varians, Micrococcus species, Burkholderia cepacia, Stenotrophomonas maltophilia, Pseudomonas paucimobilis, Pseudomonas fluorescence, Pseudomonas species, Staph. capitis, Staph. cohnii, Staph. saprophyticus, Staph. simulans, Staph. warneri, Staph. xylosus, viridans-type streptococcus and yeasts were also found in different percentage. Higher isolation rates of Acinetobacter lwoffii, Staph. aureus, Alkaligenes species, Corynebacterium species, Chryseomonas luteola, Enterobacter agglomerans, Staph. epidermidis and other coagulase negative Staphylococci were noted in children from the seven sites. However, Chryseomonas luteola, and Pseudomonas species, were found only in the groin area among males. Otherwise, no significant differences were recorded in the isolation rates from each site separately in relation to age and sex. The role of the isolated microorganisms

  20. Enhanced selection of micro-aerobic pentachlorophenol degrading granular sludge

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Yuancai, E-mail: donkey1204@hotmail.com [State Key Laboratory of Pulp and Paper Engineering, College of Light Industry and Food Science, South China University of Technology, Guangzhou 510640 (China); Chen, Yuancai, E-mail: chenyc@scut.edu.cn [State Key Laboratory of Pulp and Paper Engineering, College of Light Industry and Food Science, South China University of Technology, Guangzhou 510640 (China); Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); Song, Wenzhe, E-mail: songwenzhe007@126.com [Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); Hu, Yongyou, E-mail: ppyyhu@scut.edu.cn [State Key Laboratory of Pulp and Paper Engineering, College of Light Industry and Food Science, South China University of Technology, Guangzhou 510640 (China); Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou 510006 (China)

    2014-09-15

    Graphical abstract: In this work, an aerobic column reactor was placed before the USB to maintain micro-oxygen condition in the reactor and the micro-aerobic pentachlorophenol (PCP) degrading granular sludge under oxygen-limited conditions (0.1–0.2 mg L{sup −1}) was successfully obtained. PCP degradation by the micro-aerobic system was studied and the variance of microbial community was also discussed by using PCR-DGGE analysis. - Highlights: • Micro-aerobic granular sludge was cultivated in column-type combined reactors. • PCP biodegradation, VFA accumulation and biogas production were studied. • The function of Methanogenic archaeon in the system was investigated. • Fluctuation and diversity of microbial community were discussed by DGGE analysis. • The dominated microorganisms were identified by 16S rDNA sequences. - Abstract: Column-type combined reactors were designed to cultivate micro-aerobic pentachlorophenol (PCP) degrading granular sludge under oxygen-limited conditions (0.1–0.2 mg L{sup −1}) over 39-day experimental period. Micro-aerobic granular had both anaerobic activity (SMA: 2.34 mMCH{sub 4}/h g VSS) and aerobic activity (SOUR: 2.21 mMO{sub 2}/h g VSS). Metabolite analysis results revealed that PCP was sequentially dechlorinated to TCP, DCP, and eventually to MCP. Methanogens were not directly involved in the dechlorination of PCP, but might played a vital role in stabilizing the overall structure of the granule sludge. For Eubacteria, the Shannon Index (2.09 in inoculated granular sludge) increased both in micro-aerobic granular sludge (2.61) and PCP-degradation granular sludge (2.55). However, for Archaea, it decreased from 2.53 to 1.85 and 1.84, respectively. Although the Shannon Index demonstrated slight difference between micro-aerobic granular sludge and PCP-degradation granular sludge, the Principal Component Analysis (PCA) indicated obvious variance of the microbial composition, revealing significant effect of micro-aerobic

  1. Enhanced selection of micro-aerobic pentachlorophenol degrading granular sludge

    International Nuclear Information System (INIS)

    Graphical abstract: In this work, an aerobic column reactor was placed before the USB to maintain micro-oxygen condition in the reactor and the micro-aerobic pentachlorophenol (PCP) degrading granular sludge under oxygen-limited conditions (0.1–0.2 mg L−1) was successfully obtained. PCP degradation by the micro-aerobic system was studied and the variance of microbial community was also discussed by using PCR-DGGE analysis. - Highlights: • Micro-aerobic granular sludge was cultivated in column-type combined reactors. • PCP biodegradation, VFA accumulation and biogas production were studied. • The function of Methanogenic archaeon in the system was investigated. • Fluctuation and diversity of microbial community were discussed by DGGE analysis. • The dominated microorganisms were identified by 16S rDNA sequences. - Abstract: Column-type combined reactors were designed to cultivate micro-aerobic pentachlorophenol (PCP) degrading granular sludge under oxygen-limited conditions (0.1–0.2 mg L−1) over 39-day experimental period. Micro-aerobic granular had both anaerobic activity (SMA: 2.34 mMCH4/h g VSS) and aerobic activity (SOUR: 2.21 mMO2/h g VSS). Metabolite analysis results revealed that PCP was sequentially dechlorinated to TCP, DCP, and eventually to MCP. Methanogens were not directly involved in the dechlorination of PCP, but might played a vital role in stabilizing the overall structure of the granule sludge. For Eubacteria, the Shannon Index (2.09 in inoculated granular sludge) increased both in micro-aerobic granular sludge (2.61) and PCP-degradation granular sludge (2.55). However, for Archaea, it decreased from 2.53 to 1.85 and 1.84, respectively. Although the Shannon Index demonstrated slight difference between micro-aerobic granular sludge and PCP-degradation granular sludge, the Principal Component Analysis (PCA) indicated obvious variance of the microbial composition, revealing significant effect of micro-aerobic condition and PCP on

  2. Comparative investigation on microbial community and electricity generation in aerobic and anaerobic enriched MFCs.

    Science.gov (United States)

    Quan, Xiang-chun; Quan, Yan-ping; Tao, Kun; Jiang, Xiao-man

    2013-01-01

    This study compared the difference in microbial community and power generation capacity of air-cathode MFCs enriched under anode aerobic and anaerobic conditions. Results showed that MFCs successfully started with continuous air inputting to anode chamber. The aerobic enriched MFC produced comparable and even more electricity with the fuels of acetate, glucose and ethanol compared to the anaerobic MFC when returning to anaerobic condition. The two MFCs showed a slightly different microbial community for anode biofilms (a similarity of 77%), but a highly similar microbial community (a similarity of 97%) for anolyte microbes. The anode biofilm of aerobic enriched MFC showed the presence of some specific bacteria closely related to Clostridium sticklandii, Leucobacter komagatae and Microbacterium laevaniformans. The anaerobic enriched MFC found the presence of a large number of yeast Trichosporon sp. This research demonstrates that it is possible to enrich oxygen-tolerant anode respiring bacteria through purposely aeration in anode chamber. PMID:23196248

  3. Aerobic remediation of petroleum sludge through soil supplementation: Microbial community analysis

    International Nuclear Information System (INIS)

    Highlights: ► Enhanced aerobic-degradation of PAHs was noticed with increasing soil concentration. ► Lower ring PAHs showed superior degradation over higher ring PAHs. ► Role of dehydrogenase activity, redox pattern and dissolved oxygen was investigated. ► Community analysis detected survival of efficient aromatic degrading microorganisms. - Abstract: The effect of soil concentration on the aerobic degradation of real-field petroleum sludge was studied in slurry phase reactor. Total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAHs) showed effective removal but found to depend on the soil concentration. Aromatic fraction (48.12%) documented effective degradation compared to aliphatics (47.31%), NSO (28.69%) and asphaltenes (26.66%). PAHs profile showed efficient degradation of twelve individual aromatic compounds where lower ring compounds showed relatively higher degradation efficiency compared to the higher ring compounds. The redox behaviour and dehydrogenase activity showed a linear increment with the degradation pattern. Microbial community composition and changes during bioremediation were studied using denaturing gradient gel electrophoresis (DGGE). Among the 12 organisms identified, Proteobacteria was found to be dominant representing 50% of the total population (25% of γ-proteobacteria; 16.6% of β-proteobacteria; 8.3% of α-proteobacteria), while 33.3% were of uncultured bacteria and 16.6% were of firmicutes.

  4. Effects of gene-augmentation on the formation, characteristics and microbial community of 2,4-dichlorophenoxyacetic acid degrading aerobic microbial granules

    International Nuclear Information System (INIS)

    Highlights: ► The first study to cultivate aerobic granules capable of utilizing 2,4-D as the sole carbon source. ► Granules cultivated through gene-augmentation were first compared systematically with the control on granule formation, degradation kinetics, morphology, and microbial community. ► The first report on the fate of transconjugats in the granules during long term operation after bioaugmentation. ► The first study to isolate in dominant bacteria in 2,4-D degrading microbial granules. - Abstract: Development of 2,4-dichlorophenoxyacetic acid (2,4-D) degrading aerobic granular sludge was conducted in two sequencing batch reactors (SBR) with one bioaugmented with a plasmid pJP4 donor strain Pseudomonas putida SM1443 and the other as a control. Half-matured aerobic granules pre-grown on glucose were used as the starting seeds and a two-stage operation strategy was applied. Granules capable of utilizing 2,4-D (about 500 mg/L) as the sole carbon source was successfully cultivated in both reactors. Gene-augmentation resulted in the enhancement of 2,4-D degradation rates by the percentage of 65–135% for the granules on Day 18, and 6–24% for the granules on Day 105. Transconjugants receiving plasmid pJP4 were established in the granule microbial community after bioaugmentation and persisted till the end of operation. Compared with the control granules, the granules in the bioaugmented reactor demonstrated a better settling ability, larger size, more abundant microbial diversity and stronger tolerance to 2,4-D. The finally obtained granules in the bioaugmented and control reactor had a granule size of around 600 μm and 500 μm, a Shannon–Weaver diversity index (H) of 0.96 and 0.55, respectively. A shift in microbial community was found during the granulation process.

  5. Enhancing excess sludge aerobic digestion with low intensity ultrasound

    Institute of Scientific and Technical Information of China (English)

    DING Wen-chuan; LI Dong-xue; ZENG Xiao-lan; LONG Teng-rui

    2006-01-01

    In order to enhance the efficiency of aerobic digestion, the excess sludge was irradiated by low intensity ultrasound at a frequency of 28 kHz and acoustic intensity of 0.53 W/cm2. The results show that the sludge stabilization without ultrasonic treatment can be achieved after 17 d of digestion, whereas the digestion time of ultrasonic groups can be cut by 3 - 7 d. During the same digestion elapsing, in ultrasonic groups the total volatile suspended solid removal rate is higher than that in the control group. The kinetics of aerobic digestion of excess sludge with ultrasound can also be described with first-order reaction.

  6. Improved TNT detoxification by starch addition in a nitrogen-fixing Methylophilus-dominant aerobic microbial consortium.

    Science.gov (United States)

    Khan, Muhammad Imran; Lee, Jaejin; Yoo, Keunje; Kim, Seonghoon; Park, Joonhong

    2015-12-30

    In this study, a novel aerobic microbial consortium for the complete detoxification of 2,4,6-trinitrotoluene (TNT) was developed using starch as a slow-releasing carbon source under nitrogen-fixing conditions. Aerobic TNT biodegradation coupled with microbial growth was effectively stimulated by the co-addition of starch and TNT under nitrogen-fixing conditions. The addition of starch with TNT led to TNT mineralization via ring cleavage without accumulation of any toxic by-products, indicating improved TNT detoxification by the co-addition of starch and TNT. Pyrosequencing targeting the bacterial 16S rRNA gene suggested that Methylophilus and Pseudoxanthomonas population were significantly stimulated by the co-addition of starch and TNT and that the Methylophilus population became predominant in the consortium. Together with our previous study regarding starch-stimulated RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) degradation (Khan et al., J. Hazard. Mater. 287 (2015) 243-251), this work suggests that the co-addition of starch with a target explosive is an effective way to stimulate aerobic explosive degradation under nitrogen-fixing conditions for enhancing explosive detoxification. PMID:26342802

  7. Microbial enhanced oil recovery (MEOR).

    Science.gov (United States)

    Brown, Lewis R

    2010-06-01

    Two-thirds of the oil ever found is still in the ground even after primary and secondary production. Microbial enhanced oil recovery (MEOR) is one of the tertiary methods purported to increase oil recovery. Since 1946 more than 400 patents on MEOR have been issued, but none has gained acceptance by the oil industry. Most of the literature on MEOR is from laboratory experiments or from field trials of insufficient duration or that lack convincing proof of the process. Several authors have made recommendations required to establish MEOR as a viable method to enhance oil recovery, and until these tests are performed, MEOR will remain an unproven concept rather than a highly desirable reality. PMID:20149719

  8. Aerobic Microbial Community of Insectary Population of Phlebotomus papatasi

    OpenAIRE

    Naseh Maleki-Ravasan; Mohammad Ali Oshaghi; Sara Hajikhani; Zahra Saeidi; Amir Ahmad Akhavan; Mohsen Gerami-Shoar; Mohammad Hasan Shirazi; Bagher Yakhchali; Yavar Rassi; Davoud Afshar

    2013-01-01

    Background: Microbes particularly bacteria presenting in the gut of haematophagous insects may have an important role in the epidemiology of human infectious disease. Methods: The microbial flora of gut and surrounding environmental of a laboratory strain of Phlebotomus papatasi, the main vector of Zoonotic Cutaneous Leishmaniasis (ZCL) in the old world, was investigated. Biochemical reactions and 16s rDNA sequencing of the isolated bacteria against 24 sugars and amino acids were used for bac...

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

    KAUST Repository

    Harb, Moustapha

    2016-07-09

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

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

    Science.gov (United States)

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

    2016-10-01

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

  11. Enhanced aerobic granulation, stabilization, and nitrification in a continuous-flow bioreactor by inoculating biofilms.

    Science.gov (United States)

    Yang, Yang; Zhou, Dandan; Xu, Zhengxue; Li, Aijun; Gao, Hang; Hou, Dianxun

    2014-06-01

    In this study, the possibility of using backwashed biofilm as seed in an aerobic granular sludge continuous-flow airlift fluidized bed (CAFB) reactor was investigated. After the addition of the inoculated backwashed biofilm, the start-up period of this reactor fed with municipal wastewater was reduced to 25 days, and aerobic granulation and stabilization were enhanced. At steady state, the chemical oxygen demand (COD) removal efficiency and nitrification efficiency were as high as 80-90 and 60 %, respectively. The CAFB was operated continuously and totally for 90 days, and its performance was much more stable when compared with system inoculated with activated sludge. Microbial distribution analyzed by fluorescence in situ hybridization (FISH) showed that the nitrite-oxidizing bacteria (NOB) and ammonium-oxidizing bacteria (AOB) were compatible with heterotrophic bacteria and distributed evenly throughout the granules. Such unique population distribution might be attributed to the low COD level and abundant dissolved oxygen in the entire granule as simulated by the mathematic models. Moreover, scanning electron microscopy revealed broad holes in the granules, which might promote the mass transfer of the nutrients from the surface to the center and enable simultaneous COD removal and nitrification. In conclusion, backwashed biofilm is an alternative seed of the conventional flocculent activated sludge in the aerobic granular sludge system to enhance carbonaceous oxidization and nitrification. PMID:24643735

  12. EVALUATION OF A TWO-STAGE TREATMENT OF DOMESTIC SEWAGE WITH ANAEROBIC-AEROBIC MICROBIAL FILM

    Directory of Open Access Journals (Sweden)

    A.Mesdaghinia

    1986-08-01

    Full Text Available The objective of this research was to study the feasibility of a two stage continuous system employing anaerobic-aerobic microbial film for domestic wastewater treatment and the effect of iron on the behavior of sulfate reducing bacteria in anaerobic metabolism. A bench scale system with an anaerobic filter followed by aerobic fixed units used plastic media and was operated in up flow manner with hydraulic detention times of 6 hours, whereas the aerobic unit utilized diffused aeration. Raw domestic sewage was fed to the anaerobic unit, and the aerobic unit was fed with the anaerobic unit was fed with the anaerobic effluent. Although, the anaerobic filter did not show a considerable organic removal with domestic sex age it was improved when glucose was added to the influent to increase influent soluble COD. When glucose was added the anaerobic filter removed about 290 mg/1 of influent soluble COD. The aerobic unit produced an excellent effluent with COD, BOD5 and TSS concentrations of 37 mg/1, 9 mg/1 and 10 mg/l respectively. Overall, the system removed 95 percent of influent COD, 97 percent of influent BOD5 and 96 percent of influent TSS.

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

    Science.gov (United States)

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

    2013-08-01

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

  14. Aerobic Microbial Community of Insectary Population of Phlebotomus papatasi.

    Directory of Open Access Journals (Sweden)

    Naseh Maleki-Ravasan

    2014-06-01

    Full Text Available Microbes particularly bacteria presenting in the gut of haematophagous insects may have an important role in the epidemiology of human infectious disease.The microbial flora of gut and surrounding environmental of a laboratory strain of Phlebotomus papatasi, the main vector of Zoonotic Cutaneous Leishmaniasis (ZCL in the old world, was investigated. Biochemical reactions and 16s rDNA sequencing of the isolated bacteria against 24 sugars and amino acids were used for bacteria species identification. Common mycological media used for fungi identification as well.Most isolates belonged to the Enterobacteriaceae, a large, heterogeneous group of gram-negative rods whose natural habitat is the intestinal tract of humans and animals. Enterobacteriaceae groups included Edwardsiella, Enterobacter, Escherichia, Klebsiella, Kluyvera, Leminorella, Pantoea, Proteus, Providencia, Rahnella, Serratia, Shigella, Tatumella, and Yersinia and non Enterobacteriaceae groups included Bacillus, Staphylococcus and Pseudomonas. The most prevalent isolates were Proteus mirabilis and P. vulgaris. These saprophytic and swarming motile bacteria were isolated from all immature, pupae, and mature fed or unfed male or female sand flies as well as from larval and adult food sources. Five fungi species were also isolated from sand flies, their food sources and colonization materials where Candida sp. was common in all mentioned sources.Midgut microbiota are increasingly seen as an important factor for modulating vector competence in insect vectors so their possible effects of the mirobiota on the biology of P. papatasi and their roles in the sandfly-Leishmania interaction are discussed.

  15. Aerobic Microbial Degradation of Chlorochromate Compounds Polluting the Environment

    International Nuclear Information System (INIS)

    Eight soil and sludge samples which have been polluted with petroleum wastes for more than 41 years were used for isolation of adapted indigenous microbial communities able to mineralize the chloro aromatic compounds [3-chlorobenzoic acid (3-CBA), 2,4-dichlorophenol (2,4-DCP), 2,6-dichlorophenol indole phenol (2,6-DCPP) and 1,2,4-trichlorobenzene (1,2,4-TCB)] and use them as a sole carbon and energy sources. From these communities, the most promising bacterial strain MAM-24 which has the ability to degrade the four chosen aromatic compounds was isolated and identified by comparative sequence analysis for its 16S-rRNA coding genes and it was identified as Bacillus mucilaginosus HQ 013329. Degradation percentage was quantified by HPLC. Degradation products were identified by GC-MS analysis which revealed that the isolated strain and its mutant dechlorinated the four chloro aromatic compounds in the first step forming acetophenone which is considered as the corner stone of the intermediate compounds

  16. Cognitive enhancement by transcranial laser stimulation and acute aerobic exercise.

    Science.gov (United States)

    Hwang, Jungyun; Castelli, Darla M; Gonzalez-Lima, F

    2016-08-01

    This is the first randomized, controlled study comparing the cognitive effects of transcranial laser stimulation and acute aerobic exercise on the same cognitive tasks. We examined whether transcranial infrared laser stimulation of the prefrontal cortex, acute high-intensity aerobic exercise, or the combination may enhance performance in sustained attention and working memory tasks. Sixty healthy young adults were randomly assigned to one of the following four treatments: (1) low-level laser therapy (LLLT) with infrared laser to two forehead sites while seated (total 8 min, 1064 nm continuous wave, 250 mW/cm(2), 60 J/cm(2) per site of 13.6 cm(2)); (2) acute exercise (EX) of high-intensity (total 20 min, with 10-min treadmill running at 85-90 % VO2max); (3) combined treatment (LLLT + EX); or (4) sham control (CON). Participants were tested for prefrontal measures of sustained attention with the psychomotor vigilance task (PVT) and working memory with the delayed match-to-sample task (DMS) before and after the treatments. As compared to CON, both LLLT and EX reduced reaction time in the PVT [F(1.56) = 4.134, p = 0.01, η (2)  = 0.181] and increased the number of correct responses in the DMS [F(1.56) = 4.690, p = 0.005, η (2)  = 0.201], demonstrating a significant enhancing effect of LLLT and EX on cognitive performance. LLLT + EX effects were similar but showed no significantly greater improvement on PVT and DMS than LLLT or EX alone. The transcranial infrared laser stimulation and acute aerobic exercise treatments were similarly effective for cognitive enhancement, suggesting that they augment prefrontal cognitive functions similarly. PMID:27220529

  17. Microbial activity in subsurface samples before and during nitrate-enhanced bioremediation

    International Nuclear Information System (INIS)

    A study was conducted to determine the microbial activity at a site contaminated with JP-4 jet fuel before and during nitrate-enhanced bioremediation. Samples at three depths from six different locations were collected aseptically under anaerobic conditions before and during treatment. Cores were located in or close to the source of contamination, downgradient of the source, or outside the zone of contamination. Parameters for microbial characterization included (1) viable counts of aerobic heterotrophic, JP-4 degrading, and oligotrophic bacteria; (2) the most probable number (MPN) of aerobic and anaerobic protozoa; (3) the MPN of total denitrifiers; and (4) the MPN of denitrifiers in hydrocarbon-amended microcosms. The results indicate that the total number of denitrifiers increased by an order of magnitude during nitrate-enhanced bioremediation in most samples. The number of total heterotrophs and JP-4-degrading microorganisms growing aerobically also increased. In addition, the first anaerobic protozoa associated with hydrocarbon-contaminated subsurface materials were detected

  18. Enhanced aerobic sludge granulation with layered double hydroxide

    Directory of Open Access Journals (Sweden)

    Jizhi Zhou

    2014-06-01

    Full Text Available Aerobic granular sludge technology has been developed for the biochemical treatment of wastewater in the present study. A fast cultivation of aerobic granular sludge was realized in Sequencing Batch Reactor (SBR, where Mg-Al layered double hydroxide (LDH was used as a carrier for granules growth. In comparison, the sludge particle size with LDH addition was bigger than those without LDH, with more than 50% of compact granular sludge >1.4 mm in size. This indicatestheLDH improved the growth ofthegranular sludge. The frequency of LDH addition had little effect on the granule growth. Moreover, the formation of granules led to the low sludge volume index (SVI and high mixed liquid suspended solids (MLSS in SBR reactor. With the formation of granular sludge, more than 80% of COD was removed in SBR reactor. The high COD removal efficiency of wastewater was observed regardless of various COD loading strength. The results suggest that the growth of granular sludge with LDH as a carrier enhanced the treatment efficiency. Therefore, our results have provided a promising way to prepare the granular sludge for wastewater treatment.

  19. Aerobic microbial dolomite at the nanometer scale: Implications for the geologic record

    Science.gov (United States)

    Sánchez-Román, Mónica; Vasconcelos, Crisógono; Schmid, Thomas; Dittrich, Maria; McKenzie, Judith A.; Zenobi, Renato; Rivadeneyra, Maria A.

    2008-11-01

    Microbial experiments are the only proven approach to produceexperimental dolomite under Earth's surface conditions. Althoughmicrobial metabolisms are known to induce dolomite precipitationby favoring dolomite growth kinetics, the involvement of microbesin the dolomite nucleation process is poorly understood. Inparticular, the nucleation of microbially mediated dolomiteremains a matter for investigation because the metabolic diversityinvolved in this process has not been fully explored. Hereinwe demonstrate that Halomonas meridiana and Virgibacillus marismortui,two moderately halophilic aerobic bacteria, mediate primaryprecipitation of dolomite at low temperatures (25, 35 °C).This report emphasizes the biomineralogical implications fordolomite formation at the nanometer scale. We describe nucleationof dolomite on nanoglobules in intimate association with thebacterial cell surface. A combination of both laboratory cultureexperiments and natural samples reveals that these nanoglobulestructures may be: (1) the initial step for dolomite nucleation,(2) preserved in the geologic record, and (3) used as microbialtracers through time and/or as a proxy for ancient microbialdolomite, as well as other carbonate minerals.

  20. Location and chemical composition of microbially induced phosphorus precipitates in anaerobic and aerobic granular sludge.

    Science.gov (United States)

    Mañas, A; Spérandio, M; Decker, F; Biscans, B

    2012-01-01

    This work focuses on combined scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX) applied to granular sludge used for biological treatment of high-strength wastewater effluents. Mineral precipitation is shown to occur in the core of microbial granules under different operating conditions. Three dairy wastewater effluents, from three different upflow anaerobic sludge blanket (UASB) reactors and two aerobic granular sequenced batch reactors (GSBR) were evaluated. The relationship between the solid phase precipitation and the chemical composition of the wastewater was investigated with PHREEQC software (calculation of saturation indexes). Results showed that pH, Ca:P ratios and biological reactions played a major role in controlling the biomineralization phenomena. Thermodynamics calculations can be used to foresee the nature of bio-precipitates, but the location of the mineral concretions will need further investigation as it is certainly due to local microbial activity. PMID:23393959

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

    Science.gov (United States)

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

    2016-03-15

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

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

    OpenAIRE

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

    2013-01-01

    Methane can be used as an alternative carbon source in biological denitrification because it is nontoxic, widely available and relatively inexpensive. A microbial consortium involved in methane oxidation coupled to denitrification (MOD) was enriched with nitrite and nitrate as electron acceptors under micro-aerobic conditions. The 16S rRNA gene combined with pmoA phylogeny of methanotrophs and nirK phylogeny of denitrifiers were analysed to reveal the dominant microbial populations and functi...

  3. Physicochemical and Microbial Caracteristics Performency in Wastewater Treated Under Aerobic Reactor

    Directory of Open Access Journals (Sweden)

    Asma B. Rajeb

    2011-01-01

    Full Text Available Problem statement: The current work study the efficiency of biological wastewater treatment by an aerobic reactor which could be used in small agglomerations. RBC reduced physicochemical and microbiological load of wastewater but values remain above Tunisian standard. Approach: Experiments were conducted on a sand filled PVC column fed with wastewater treated by Rotating Biological Contactor (RBC at a pulsed rhythm of 8 sequences per day. For performances study process, physicochemical and bacterial analyses effluent at inlet and outlet of column were realized. Results: The results showed that through filter mass (D10 = 0.55 mm, D60 = 1.3 mm and coefficient uniformity = 2.36 96% of suspended solids, 99% of NH4 +-N (during first phase, 92% of COD, 91% of BOD5 and 46% of phosphorus are retained by surface filtration. The microbial abatement results is E. coli. The microbial water quality is slightly higher than Tunisian standards. The removal of microbial indicators in the considered reactor depends on the depth of the filter and negatively correlated with NO3 --N (r = -0.99, with E. coli at 3rd OPD. Conclusion/Recommendation: Results confirmed that the reactor tested is performed as an advanced treatment system for DBO, COD, SS, NH4 +-N and NO3 --N. Despite that 96% of SS efficiency reduction, clogging is not achieved quickly that due to biofilm detachment phenomena. The removal of microbial indicators in the considered reactor depends on the depth of the filter and negatively correlated with NO3 --N. Disinfection performances for the considered reactor reduce microbial load, however chlore, ozone or UV disinfection should be considered.

  4. The Effect of Microbial Inoculants Applied at Ensiling on Sorghum Silage Characteristics and Aerobic Stability

    Institute of Scientific and Technical Information of China (English)

    GUAN Wu-tai; Ashbell G; Hen Y; Weinberg Z G

    2002-01-01

    Whole crop forage sorghum (Saccharatum) cultivar FS5 was harvested at the soft dough stage of maturity. The sorghum was chopped to approximately 2 cm pieces and ensiled under laboratory conditions in 1.5 L Weck glass jars. At ensiling, it was treated with two commercial microbial inoculants: inoculant A and inoculant B. The inoculants were applied at 2 × 105 colony forming units g- 1 DM. Silage with no additives served as a control. Three jars per treatment were opened on days 2, 4, 8, 15 and 60 post-ensiling to study fermentation dynamics. After 60 days of ensiling, the silages were analyzed and subjected to an aerobic stability test lasting 5 days. Results showed that both inoculants caused a more rapid rate of pH decline and a higher amount of lactic acid production. Silages treated with each inoculant produced a little more CO2 and resulted in more glucose loss as compared with the control. Addition of inoculants did not influence ( P > 0.05) the ash and crude protein contents, but tended to decrease the concentration of acetic acid (P < 0.05), butyric acid (P < 0.01) and propionic acid ( P < 0.01 ), and increase the lactic acid concentration ( P < 0.01 ). Silages treated with inoculant A possess the more DM loss, and the higher yeast counts upon aerobic exposure. Silage treated with inoculant B had the most DM (P < 0.05), lactic acid contents (P < 0.01 ), the least acetic acid content (P < 0.05). Inoculant B reduced the ADF (P < 0.01), ADL and NDF ( P < 0.05) contents. It was concluded that lactic bacteria inoculants may improve the fermentation but might impair the aerobic stability for sorghum ensilage.

  5. Surface Chemistry Enhanced Microbial Bioelectrocatalysis

    Science.gov (United States)

    Santoro, Carlo; Babanova, Sofia; Artyushkova, Kateryna; Cornejo, Jose’ A.; Ista, Linnea; Bretschger, Orianna; Marsili, Enrico; Atanassov, Plamen; Schuler, Andrew J.

    2016-01-01

    Self-assembled monolayers (SAMs) modified gold anodes are used in single chamber microbial fuel cells (SCMFC) for organics removal and electricity generation. Hydrophilic (−N(CH3)3+, −OH, −COOH) and hydrophobic (−CH3) SAMs are examined for their effect on bacterial attachment, current and power output. The different substratum chemistry affects both the current and power output and the community composition of the electrochemically active biofilm formed. Of the four SAM-modified anode tested, −N(CH3)3+ results in shortest start up time, highest single electrode polarization and power density, followed by −OH and –COOH SAMs. Hydrophobic SAM decreases bacteria attachment and anodes performance in comparison to hydrophilic SAMs. Electron transfer rate is faster on the N(CH3)3+-surface than on other surfaces, and correlates with a high abundance of δ-Proteobacteria, including electrochemically active species. A consortium of Clostridia and δ-Proteobacteria is found on all the anode surfaces, suggesting a synergistic cooperation under anodic conditions. PMID:26025340

  6. Effect of microbial inoculants on the quality and aerobic stability of bermudagrass round-bale haylage.

    Science.gov (United States)

    Arriola, K G; Queiroz, O C M; Romero, J J; Casper, D; Muniz, E; Hamie, J; Adesogan, A T

    2015-01-01

    The objective of this study was to compare the efficacy of using 4 commercially available microbial inoculants to improve the fermentation and aerobic stability of bermudagrass haylage. We hypothesized that the microbial inoculants would increase the fermentation and aerobic stability of the haylages. Bermudagrass (4-wk regrowth) was harvested and treated with (1) deionized water (control); (2) Buchneri 500 (B500; Lallemand Animal Nutrition, Milwaukee, WI) containing 1×10(5) of Pediococcus pentosaceus and 4×10(5) of Lactobacillus buchneri 40788; (3) Biotal Plus II (BPII; Lallemand Animal Nutrition) containing 1.2×10(5) of P. pentosaceus and Propionibacteria freudenreichii; (4) Silage Inoculant II (SI; AgriKing Inc., Fulton, IL) containing 1×10(5) of Lactobacillus plantarum and P. pentosaceus; and (5) Silo King (SK; AgriKing Inc.), containing 1×10(5) of L. plantarum, Enterococcus faecium, and P. pentosaceus, respectively. Forty round bales (8 per treatment; 441±26kg; 1.2×1.2 m diameter) were made and each was wrapped with 7 layers of plastic. Twenty bales were stored for 112 d and the remaining 20 were stored for 30 d and sampled by coring after intermediary storage periods of 0, 3, 7, and 30 d. The pH of control and inoculated haylages sampled on d 3 did not differ. However, B500 and BPII had lower pH (5.77±0.04 vs. 6.16±0.04; 5.06±0.13 vs. 5.52±0.13) than other treatments by d 7 and 30, respectively. At final bale opening on d 112, all treatments had lower pH than the control haylage (4.77±0.07 vs. 5.37±0.07). The B500, BPII, and SI haylages had greater lactic acid and lactic-to-acetic acid ratios than SK and control haylages. No differences were detected in neutral detergent fiber digestibility, dry matter losses, dry matter, lactic and acetic acid concentrations, and yeast and coliform counts. The SK haylage had lower clostridia counts compared with the control (1.19±0.23 vs. 1.99±0.23 cfu/g). Treatments B500, BPII, SI, and SK tended to reduce

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

    International Nuclear Information System (INIS)

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

  8. Improved RDX detoxification with starch addition using a novel nitrogen-fixing aerobic microbial consortium from soil contaminated with explosives.

    Science.gov (United States)

    Khan, Muhammad Imran; Yang, Jihoon; Yoo, Byungun; Park, Joonhong

    2015-04-28

    In this work, we developed and characterized a novel nitrogen-fixing aerobic microbial consortium for the complete detoxification of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). Aerobic RDX biodegradation coupled with microbial growth and nitrogen fixation activity were effectively stimulated by the co-addition of starch and RDX under nitrogen limiting conditions. In the starch-stimulated nitrogen-fixing RDX degradative consortium, the RDX degradation activity was correlated with the xplA and nifH gene copy numbers, suggesting the involvement of nitrogen fixing populations in RDX biodegradation. Formate, nitrite, nitrate, and ammonia were detected as aerobic RDX degradation intermediates without the accumulation of any nitroso-derivatives or NDAB (4-nitro-2,4-diazabutanal), indicating nearly complete mineralization. Pyrosequencing targeting the bacterial 16S rRNA genes revealed that the Rhizobium, Rhizobacter and Terrimonas population increased as the RDX degradation activity increased, suggesting their involvement in the degradation process. These findings imply that the nitrogen-fixing aerobic RDX degrading consortium is a valuable microbial resource for improving the detoxification of RDX-contaminated soil or groundwater, especially when combined with rhizoremediation. PMID:25661171

  9. Microbial Enhanced Oil Recovery - Advanced Reservoir Simulation

    OpenAIRE

    Nielsen, Sidsel Marie; Shapiro, Alexander; Stenby, Erling Halfdan; Michelsen, Michael Locht

    2010-01-01

    In this project, a generic model has been set up to include the two main mechanisms in the microbial enhanced oil recovery (MEOR) process; reduction of the interfacial tension (IFT) due to surfactant production, and microscopic fluid diversion as a part of the overall fluid diversion mechanism due to formation of biofilm. The construction of a one-dimensional simulator enables us to investigate how the different mechanisms and the combination of these influence the displacement processes, the...

  10. Evaluation of microbial transport during aerobic bioaugmentation of an RDX-contaminated aquifer.

    Science.gov (United States)

    Crocker, Fiona H; Indest, Karl J; Jung, Carina M; Hancock, Dawn E; Fuller, Mark E; Hatzinger, Paul B; Vainberg, Simon; Istok, Jonathan D; Wilson, Edward; Michalsen, Mandy M

    2015-11-01

    In situ bioaugmentation with aerobic hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)-degrading bacteria is being considered for treatment of explosives-contaminated groundwater at Umatilla Chemical Depot, Oregon (UMCD). Two forced-gradient bacterial transport tests of site groundwater containing chloride or bromide tracer and either a mixed culture of Gordonia sp. KTR9 (xplA (+)Km(R)), Rhodococcus jostii RHA1 (pGKT2 transconjugant; xplA (+)Km(R)) and Pseudomonas fluorescens I-C (xenB (+)), or a single culture of Gordonia sp. KTR9 (xplA (+); i.e. wild-type) were conducted at UMCD. Groundwater monitoring evaluated cell viability and migration in the injection well and downgradient monitoring wells. Enhanced degradation of RDX was not evaluated in these demonstrations. Quantitative PCR analysis of xplA, the kanamycin resistance gene (aph), and xenB indicated that the mixed culture was transported at least 3 m within 2 h of injection. During a subsequent field injection of bioaugmented groundwater, strain KTR9 (wild-type) migrated up to 23-m downgradient of the injection well within 3 days. Thus, the three RDX-degrading strains were effectively introduced and transported within the UMCD aquifer. This demonstration represents an innovative application of bioaugmentation to potentially enhance RDX biodegradation in aerobic aquifers. PMID:26438043

  11. Bioaugmentation of aerobic sludge granules with a plasmid donor strain for enhanced degradation of 2,4-dichlorophenoxyacetic acid

    International Nuclear Information System (INIS)

    Aerobic sludge granules pre-grown on glucose were bioaugmented with a plasmid pJP4 carrying strain Pseudomonas putida SM1443 in a fed-batch microcosm system and a lab-scale sequencing batch reactor (SBR) to enhance their degradation capacity to 2,4-dichlorophenoxyacetic acid (2,4-D). The fed-batch test results showed that the bioaugmented aerobic granule system gained 2,4-D degradation ability faster and maintained a more stable microbial community than the control in the presence of 2,4-D. 2,4-D at the initial concentration of about 160 mg/L was nearly completely removed by the bioaugmented granule system within 62 h, while the control system only removed 26% within 66 h. In the bioaugmented SBR which had been operated for 90 days, the seeded aerobic granules pre-grown on glucose successfully turned into 2,4-D degrading granules through bioaugmentation and stepwise increase of 2,4-D concentration from 8 to 385 mg/L. The granules showed a compact structure and good settling ability with the mean diameter of about 450 μm. The degradation kinetics of 2,4-D by the aerobic granules can be described with the Haldane kinetics model with Vmax = 31.1 mg 2,4-D/gVSS h, Ki = 597.9 mg/L and Ks = 257.3 mg/L, respectively. This study shows that plasmid mediated bioaugmentation is a feasible strategy to cultivate aerobic granules degrading recalcitrant pollutants.

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

    Science.gov (United States)

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

    2011-01-01

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

  13. Aerobic training enhances muscle deoxygenation in early post-myocardial infarction

    OpenAIRE

    Takagi, Shun; Murase, Norio; Kime, Ryotaro; Niwayama, Masatsugu; Osada, Takuya; Katsumura, Toshihito

    2016-01-01

    Purpose Exercise-induced skeletal muscle deoxygenation is startling by its absence in early post-myocardial infarction (MI) patients. Exercise training early post-MI is associated with reduced cardiovascular risk and increased aerobic capacity. We therefore investigated whether aerobic training could enhance the muscle deoxygenation in early post-MI patients. Methods 21 ± 8 days after the first MI patients (n = 16) were divided into 12-week aerobic training (TR, n = 10) or non-training (CON, ...

  14. Starting up microbial enhanced oil recovery.

    Science.gov (United States)

    Siegert, Michael; Sitte, Jana; Galushko, Alexander; Krüger, Martin

    2014-01-01

    This chapter gives the reader a practical introduction into microbial enhanced oil recovery (MEOR) including the microbial production of natural gas from oil. Decision makers who consider the use of one of these technologies are provided with the required scientific background as well as with practical advice for upgrading an existing laboratory in order to conduct microbiological experiments. We believe that the conversion of residual oil into natural gas (methane) and the in situ production of biosurfactants are the most promising approaches for MEOR and therefore focus on these topics. Moreover, we give an introduction to the microbiology of oilfields and demonstrate that in situ microorganisms as well as injected cultures can help displace unrecoverable oil in place (OIP). After an initial research phase, the enhanced oil recovery (EOR) manager must decide whether MEOR would be economical. MEOR generally improves oil production but the increment may not justify the investment. Therefore, we provide a brief economical assessment at the end of this chapter. We describe the necessary state-of-the-art scientific equipment to guide EOR managers towards an appropriate MEOR strategy. Because it is inevitable to characterize the microbial community of an oilfield that should be treated using MEOR techniques, we describe three complementary start-up approaches. These are: (i) culturing methods, (ii) the characterization of microbial communities and possible bio-geochemical pathways by using molecular biology methods, and (iii) interfacial tension measurements. In conclusion, we hope that this chapter will facilitate a decision on whether to launch MEOR activities. We also provide an update on relevant literature for experienced MEOR researchers and oilfield operators. Microbiologists will learn about basic principles of interface physics needed to study the impact of microorganisms living on oil droplets. Last but not least, students and technicians trying to understand

  15. A novel biosensor for p-nitrophenol based on an aerobic anode microbial fuel cell.

    Science.gov (United States)

    Chen, Zhengjun; Niu, Yongyan; Zhao, Shuai; Khan, Aman; Ling, Zhenmin; Chen, Yong; Liu, Pu; Li, Xiangkai

    2016-11-15

    P-nitrophenol is one of the most common contaminants in chemical industrial wastewater, and in situ real-time monitoring of PNP cannot be achieved by conventional analytical techniques. Here, a two-chamber microbial fuel cell with an aerobic anode chamber was tested as a biosensor for in situ real-time monitoring of PNP. Pseudomonas monteilii LZU-3, which was used as the biological recognition element, can form a biofilm on the anode electrode using PNP as a sole substrate. The optimal operation parameters of the biosensor were as follows: external resistance 1000Ω, pH 7.8, temperature 30°C, and maximum PNP concentration 50mgL(-1). Under these conditions, the maximum voltages showed a linear relationship with PNP concentrations ranging from 15±5 to 44±4.5mgL(-1). Furthermore, we developed a novel portable device for in situ real-time monitoring of PNP. When the device was applied to measure PNP in wastewater containing various additional aromatic compounds and metal ions, the performance of the biosensor was not affected and the correlation between the maximum voltages and the PNP concentrations ranging from 9±4mgL(-1) to 36 ± 5mgL(-1) was conserved. The results demonstrated that the MFC biosensor provides a rapid and cost-efficient analytical method for real-time monitoring of toxic and recalcitrant pollutants in environmental samples. PMID:27295573

  16. Effect of wastewater COD/N ratio on aerobic nitrifying sludge granulation and microbial population shift

    Institute of Scientific and Technical Information of China (English)

    Lei Wu; Chengyao Peng; Yongzhen Peng; Lingyun Li; Shuying Wang; Yong Ma

    2012-01-01

    The effect of COD/N ratio on the granulation process and microbial population succession was investigated.Four identical sequencing batch reactors,R1,R2,R3 and R4,were operated with various initial COD/N ratios ranging from 0/200 to 800/200 (m/n).Ethanol was fed as the source of COD.Aerobic granules were successfully cultivated in R2 and R3,operating with the COD/N ratio of 200/200 and 400/200,respectively.Scanning electron microscope observations indicated that short rod-shaped and spherical bacteria were dominant in R2,while granules produced in R3 were surrounded with a large amount of filamentous bacteria.The average specific nitritation rate in R2 and R3 were 0.019 and 0.008 mg N/(mg MLVSS.hr),respectively.Fluorescence in situ hybridization results demonstrated that nitrifying bacteria population was enriched remarkably in R2.It indicated that nitrification ability and nitrifying bacteria population were enriched remarkably at low COD/N ratio.However,no granules were formed in R1and R4 which might attribute to either limited or excessive extracellular polymeric substances production.This study contributed to a better understanding of the role of COD/N ratio in nitrifying sludge granulation.

  17. Species and distribution of inorganic and organic phosphorus in enhanced phosphorus removal aerobic granular sludge.

    Science.gov (United States)

    Huang, Wenli; Huang, Weiwei; Li, Huifang; Lei, Zhongfang; Zhang, Zhenya; Tay, Joo Hwa; Lee, Duu-Jong

    2015-10-01

    The species and distribution of phosphorus (P) in an enhanced biological phosphorus removal (EBPR)-aerobic granular sludge (AGS) were fractionated and further analyzed. Results showed that microbial cells, extracellular polymeric substances (EPS) and mineral precipitates contributed about 73.7%, 17.6% and 5.3-6.4% to the total P (TP) of EBPR-AGS, respectively. Inorganic P (IP) species were orthophosphate, pyrophosphate and polyphosphate among which polyphosphate was the major P species in the AGS, cells and EPS. Monoester and diester phosphates were identified as the organic P (OP) species in the AGS and cells. Hydroxyapatite (Ca5(PO4)3OH) and calcium phosphate (Ca2(PO4)3) were the dominant P minerals accumulated in the core of the granules. Cells along with polyphosphate were mainly in the outer layer of AGS while EPS were distributed in the whole granules. Based on the above results, the distribution of IP and OP species in AGS has been conceived. PMID:26144019

  18. Microbial enhanced oil recovery. A short review

    Energy Technology Data Exchange (ETDEWEB)

    Zekri, A.Y. [United Arab Emirates Univ., Al Ain (United Arab Emirates)

    2001-03-01

    Several literature reviews have been published on microbial enhanced oil recovery (MEOR). This paper updates the state of art in MEOR process and presents a summary of field projects. The most common practice technique of MEOR is cyclic stimulation treatment of production wells. Normally small amount of microbial solution injected in a single well and left to soak for a period of time before putting the well back on production. This process results in a limited volume of the reservoir being treated. This usual type of treatment is easy to implement, quick response and relatively inexpensive. The second technique is to apply microbial along with water flooding to improve both sweep efficiency and displacement efficiency. A number of projects have been conducted to improve oil recovery using MEOR technique. In laboratory, bacteria have been shown to produce chemicals such as surfactant, acids, solvents and gases (mainly CO{sub 2}) that can extensively contribute to improvement of displacement efficiency. Microorganism growth at substantial rate and some are capable of polymer production, which resulted in improving the volumetric sweep efficiency of the process and consequently improvement of oil recovery. MEOR process is friendly to the environment, which is an addition plus to the process. In this paper a complete review of the current laboratory work and field projects will be presented in additional to reviewing the mechanism of the process in details. (orig.)

  19. Enhanced biodegradation of hydrocarbon-contaminated sediments using microbial fuel cells

    International Nuclear Information System (INIS)

    Highlights: ► One of the 1st studies on sediments MFC-enhanced hydrocarbon degradation. ► MFCs realizes close-to-aerobic biodegradation in anaerobic sediments. ► MFC-enhanced in situ biodegradation is 12× fold of the background sediments. ► Wicking electrode design increases DO in sediments while enhancing degradation. ► Results offers a passive, effective remedy for cleaning HC contaminated sediments. - Abstract: A sediment microbial fuel cell (MFC) was tested to determine if electron transfer from the anaerobic zone of contaminated sediments to the overlying aerobic water could facilitate an enhanced and aerobic equivalent degradation of total petroleum hydrocarbons (TPH). Results indicate that voltages as high as 190 mV (2162 mW/m3) were achieved in a sediment MFC with an anode buried in sediments containing TPH concentrations at approximately 16,000 mg kg−1. Additionally, after approximately 66 days, the TPH degradation rates were 2% and 24% in the open-circuit control sediment MFC and active sediment MFC, respectively. Therefore, it appears that applying MFC technology to contaminated sediments enhances natural biodegradation by nearly 12 fold. Additionally, a novel sediment MFC was designed to provide a cost-effective method of passive oxidation or indirect aerobic degradation of contaminants in an otherwise anaerobic environment. In addition, the use of a wicking air cathode in this study maintained dissolved oxygen concentrations 1–2 mg l−1 higher than submerged cathodes, demonstrating that this technology can be applied to environments with either aerobic or anaerobic overlying water and an anaerobic matrix, such as shallow lagoon, ponds, and marshes, and groundwater.

  20. Interaction of Polybrominated Diphenyl Ethers and Aerobic Granular Sludge: Biosorption and Microbial Degradation

    OpenAIRE

    Shou-Qing Ni; Qingjie Cui; Zhen Zheng

    2014-01-01

    As a new category of persistent organic pollutants, polybrominated diphenyl ethers (PBDEs) have become ubiquitous global environmental contaminants. No literature is available on the aerobic biotransformation of decabromodiphenyl ether (BDE-209). Herein, we investigated the interaction of PBDEs with aerobic granular sludge. The results show that the removal of BDE-209 from wastewater is mainly via biosorption onto aerobic granular sludge. The uptake capacity increased when temperature, contac...

  1. Microbial Mechanisms Enhancing Soil C Storage

    Energy Technology Data Exchange (ETDEWEB)

    Zak, Donald [Univ. of Michigan, Ann Arbor, MI (United States)

    2015-09-24

    Human activity has globally increased the amount of nitrogen (N) entering ecosystems, which could foster higher rates of C sequestration in the N-limited forests of the Northern Hemisphere. Presently, these ecosystems are a large global sink for atmospheric CO2, the magnitude of which could be influenced by the input of human-derived N from the atmosphere. Nevertheless, empirical studies and simulation models suggest that anthropogenic N deposition could have either an important or inconsequential effect on C storage in forests of the Northern Hemisphere, a set of observations that continues to fuel scientific discourse. Although a relatively simple set of physiological processes control the C balance of terrestrial ecosystems, we still fail to understand how these processes directly and indirectly respond to greater N availability in the environment. The uptake of anthropogenic N by N-limited forest trees and a subsequent enhancement of net primary productivity have been the primary mechanisms thought to increase ecosystem C storage in Northern Hemisphere forests. However, there are reasons to expect that anthropogenic N deposition could slow microbial activity in soil, decrease litter decay, and increase soil C storage. Fungi dominate the decay of plant detritus in forests and, under laboratory conditions, high inorganic N concentrations can repress the transcription of genes coding for enzymes which depolymerize lignin in plant detritus; this observation presents the possibility that anthropogenic N deposition could elicit a similar effect under field conditions. In our 18-yr-long field experiment, we have been able to document that simulated N deposition, at a rate expected in the near future, resulted in a significant decline in cellulolytic and lignolytic microbial activity, slowed plant litter decay, and increased soil C storage (+10%); this response is not portrayed in any biogeochemical model simulating the effect of atmospheric N deposition on ecosystem C

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

    International Nuclear Information System (INIS)

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

  3. Comparison of Ca2+ and Mg2+ enhancing aerobic granulation in SBR

    International Nuclear Information System (INIS)

    Two sequencing batch reactors (SBRs) were operated to investigate the effect of Ca2+ and Mg2+ augmentation on aerobic granulation. Reactor R1 was augmented with Ca2+ at 40 mg/L, while Mg2+ was added to the reactor R2 with 40 mg/L. Results showed that the reactor R1 had a faster granulation process compared with R2, and the mature granules in R1 showed better physical characteristics. However, the mature granules in R2 had the higher production yield of polysaccharides and proteins, and aerobic granules in R2 experienced a faster substrate biodegradation. Microbial and genetic characteristics in mature granules were analyzed using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) techniques. The results revealed that Mg2+ addition led to higher microbial diversity in mature granules. In addition, an uncultured bacterium (AB447697) was major specie in R1, and β-proteobacterium was dominant in R2. It can be concluded that Ca2+ had an important effect on physical properties of aerobic granules, while Mg2+ played a key role on biological properties during the sludge granulation.

  4. Microbial enhanced oil recovery: Entering the log phase

    Energy Technology Data Exchange (ETDEWEB)

    Bryant, R.S.

    1995-12-31

    Microbial enhanced oil recovery (MEOR) technology has advanced internationally since 1980 from a laboratory-based evaluation of microbial processes to field applications. In order to adequately support the decline in oil production in certain areas, research on cost-effective technologies such as microbial enhanced oil recovery processes must focus on both near-term and long-term applications. Many marginal wells are desperately in need of an inexpensive improved oil recovery technology today that can assist producers in order to prevent their abandonment. Microbial enhanced waterflooding technology has also been shown to be an economically feasible technology in the United States. Complementary environmental research and development will also be required to address any potential environmental impacts of microbial processes. In 1995 at this conference, the goal is to further document and promote microbial processes for improved oil recovery and related technology for solving environmental problems.

  5. Methods of lab silos sealing and fermentation characteristics and aerobic stability of sugarcane silage treated with microbial additive

    Directory of Open Access Journals (Sweden)

    Charles Ortiz Novinski

    2012-02-01

    Full Text Available The present experimental assay evaluated the effect of lab silo sealing methods on the ensilage of the sugarcane, with or without microbial additives (Lactobacillus plantarum and Propionibacterium acidipropionici. Twenty-liter plastic buckets were used as experimental silos, which were sealed with either a polyethylene sheet (silo cover with a mesh size of 200 µm or an appropriate plastic lid equipped with Bunsen valve. Silos were stored for 30, 60, or 90 days. Fermentative losses, chemical composition, organic acids, ethanol and aerobic stability were evaluated. The sealing method employed did not influence most of evaluated variables, showing a small decrease of effluent production in silos covered with polyethylene sheet. The microbial additive did not avoid dry matter (DM fermentative losses in sugarcane silages (216 g kg-1, nor affected aerobic stability (44.6 hours. The levels of neutral and acid detergent fiber of fresh sugarcane increased after ensiling due to DM losses as gases and effluent. The ethanol content of silages was not influenced by treatments (mean 146 g kg-1 of DM. The sealing methods of experimental silos were not affected by the evaluated variables; polyethylene sheet and plastic lid show the same performance on the fermentative model and both methods represent well the conditions of large scale farm silos.

  6. Enhancing Metagenomics Investigations of Microbial Interactions with Biofilm Technology

    OpenAIRE

    Kakirde, Kavita S.; McLean, Robert J. C.

    2013-01-01

    Investigations of microbial ecology and diversity have been greatly enhanced by the application of culture-independent techniques. One such approach, metagenomics, involves sample collections from soil, water, and other environments. Extracted nucleic acids from bulk environmental samples are sequenced and analyzed, which allows microbial interactions to be inferred on the basis of bioinformatics calculations. In most environments, microbial interactions occur predominately in surface-adheren...

  7. Microbial enhancement of oil recovery: Recent advances

    Energy Technology Data Exchange (ETDEWEB)

    Premuzic, E.T.; Woodhead, A.D.; Vivirito, K.J. (eds.)

    1992-01-01

    During recent years, systematic, scientific, and engineering effort by researchers in the United States and abroad, has established the scientific basis for Microbial Enhanced Oil Recovery (MEOR) technology. The successful application of MEOR technology as an oil recovery process is a goal of the Department of Energy (DOE). Research efforts involving aspects of MEOR in the microbiological, biochemical, and engineering fields led DOE to sponsor an International Conference at Brookhaven National Laboratory in 1992, to facilitate the exchange of information and a discussion of ideas for the future research emphasis. At this, the Fourth International MEOR Conference, where international attendees from 12 countries presented a total of 35 papers, participants saw an equal distribution between research'' and field applications.'' In addition, several modeling and state-of-the-art'' presentations summed up the present status of MEOR science and engineering. Individual papers in this proceedings have been process separately for inclusion in the Energy Science and Technology Database.

  8. Enhanced pyrene degradation by a microbial surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Harper, J.D.; Churchill, P.F. [Univ. of Alabama, Tuscaloosa, AL (United States); Churchill, S.A. [Washington State Univ., Pullman, WA (United States)

    1996-10-01

    A microbial biosurfactant was investigated for its ability to enhance the biodegradation of a bacterial enrichment culture. The biosurfactants used in this study were a mixture of rhamnolipids produced by Pseudomonas aeruginosa ATCC 9027 grown in phosphate-limited media. The rhamnolipid preparation was found to lower the surface tension of a phosphate buffered solution to 32 dyne cm{sup -1} and to dramatically increase the apparent aqueous solubility of pyrene. The mineralization of [{sup 14}C]-pyrene in liquid phase and in soil-water systems was quantified by measuring the production of [{sup 14}C]-carbon dioxide. In liquid phase studies, an initial lag phase was observed when rhamnolipid was added at concentrations higher than the CMC. However, mineralization in the surfactant amended cultures eventually exceeded that observed in unamended samples. In soil-water systems, mineralization was slightly more rapid in rhamnolipid amended samples then in unamended samples. These results suggest that rhamnolipids may help facilitate bioremediation of polycyclic aromatic hydrocarbons.

  9. About the order in aerobic heterotrophic microbial communities from hydrocarbon-contaminated sites

    NARCIS (Netherlands)

    Becker, P.M.

    1999-01-01

    The organizational structure of communities of aerobic heterotrophic bacteria was studied by means of physiological and molecular typing of the members of arbitrary samples of isolates, ASsI. The isolate sample assay (ISA) was applied to three different hydrocarbon-polluted sites: a dry windrow pile

  10. Microbial Enhanced Oil Recovery - Modeling and Numerical Simulations

    OpenAIRE

    Amundsen, Aleksander

    2015-01-01

    This thesis examines the process by which microbes are used to enhance oil recovery from subsurface reservoirs. A brief introduction to reservoirs is given and the possible effects of microbes are explained. A model is developed combining porous media flow and microbial kinetics. The model is then used to run simulations in conjunction with the MATLAB Reservoir Simulation Toolbox from SINTEF (Stiftelsen for Industriell og Teknisk Forskning). Microbial enhanced oil recovery (MEOR) is simulated...

  11. Understanding of aerobic granulation enhanced by starvation in the perspective of quorum sensing.

    Science.gov (United States)

    Liu, Xiang; Sun, Supu; Ma, Buyun; Zhang, Chen; Wan, Chunli; Lee, Duu-Jong

    2016-04-01

    Three sequencing batch reactors (M1, M2, and M3) were set up to investigate the influence of different lengths of starvation time (3, 5, and 7 h) on aerobic granulation in the perspective of quorum sensing (QS). Autoinducer-2 (AI-2) level was quantified to evaluate the QS ability of aerobic granules. The results indicated that AI-2 level increased steadily during a cycle of sequencing batch reactors, suggesting that starvation was closely related to AI-2 secretion. In the long-term operation, aerobic granules cultivated using a prolonged starvation period had a better integrity and a higher level of cell adhesiveness despite a slower formation speed. With the extension of the starvation period, the total amount of extracellular polymeric substances (EPS) displayed an increasing tendency. EPS with large molecular weight (MW) also reached a higher level using a prolonged starvation period. However, a higher level of AI-2 and cell adhesiveness was observed in M2, which might be related to more stable granules. The results implied that the starvation period could trigger AI-2 secretion and promoted the production of large MW EPS, leading to cell adhesiveness enhancement and granule formation. Therefore, a combination of different starvation periods was proposed in this study in order to improve aerobic granulation. PMID:26695156

  12. Effects of microbial inoculants on corn silage fermentation, microbial contents, aerobic stability, and milk production under field conditions

    DEFF Research Database (Denmark)

    Kristensen, Niels Bastian; Sloth, Karen Helle; Højberg, Ole;

    2010-01-01

    The present study aimed to investigate the effects of 2 corn silage inoculation strategies (homofermentative vs. heterofermentative inoculation) under field conditions and to monitor responses in silage variables over the feeding season from January to August. Thirty-nine commercial dairy farms...... sufficiently from the epiphytic flora on whole-crop corn to affect fermentation in standard qualities of corn silage. Heterofermentative inoculation increased aerobic stability and numerous fermentation variables. None of the treatments affected milk production, and more-stable corn silage seemed to have a...

  13. Microbial enhancement of non-Darcy flow: Theoretical consideration

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Jianxin; Schneider, D.R.

    1995-12-31

    In the near well-bore region and perforations, petroleum fluids usually flow at high velocities and may exhibit non-Darcy-flow behavior. Microorganisms can increase permeability and porosity by removing paraffin or asphaltene accumulations. They can also reduce interfacial tension by producing biosurfactants. These changes can significantly affect non-Darcy flow behavior. Theoretical analysis shows that microbial activities can enhance production by decreasing the turbulence pressure drop and in some cases increasing the drag force exerted to the oil phase. This implies that the effects of microbial activities on non-Darcy flow are important and should be considered in the evaluation of microbial well stimulation and enhanced oil recovery.

  14. Effect of microbial inoculant or molasses on fermentative quality and aerobic stability of sawdust-based spent mushroom substrate.

    Science.gov (United States)

    Kim, J S; Lee, Y H; Kim, Y I; Ahmadi, F; Oh, Y K; Park, J M; Kwak, W S

    2016-09-01

    In the first experiment, the effect of two novel Lactobacillus plantarum strains was studied on the fermentation of spent mushroom substrate (SMS) through 10d of ensiling. Based on lactic acid production and lactic acid bacteria population, L. plantarum KU5 was identified as the best strain for fermentation with a 5-L bag silo. Spent mushroom substrate was ensiled with 0.5% (v/w) L. plantarum KU5 without or with 5% molasses. Silages treated with microbial inoculant and molasses had the lowest pH and the highest fermentative odors. In a second set of experiments similar to the above 5-L silo study, the simultaneous application of L. plantarum KU5 inoculant and molasses to 80-L silos improved fermentability and aerobic stability of SMS silages. For similar treatment using ton-bag silos, aerobic stability decreased and NH3-N content increased dramatically. In conclusion, sawdust-based SMS for animal use was successfully ensiled with L. plantarum KU5 inoculant and molasses. PMID:27240234

  15. Microbially influenced corrosion of stainless steels by aerobic bacteria; Kokisei saikin no kanyoshita sutenresu ko no biseibutsu fushoku

    Energy Technology Data Exchange (ETDEWEB)

    Amaya, H.; Miyuki, H. [Sumitomo Metal Inductries Ltd., Osaka (Japan). Corporate Research and Development Lab.

    1996-03-20

    Influence of microorganisms on the corrosion of metals has been recognized since Kuhr proposed the hypothesis of corrosion promotion due to so called hydrogen double electrode when hydrogen formed in corrosion reaction of steel is used by anaerobic bacteria. Corrosion of metals caused by the influence of such type of microorganisms is known as Microbially influenced corrosion (MIC), and recently is paid attention specially in Europe and America. These recent years, research on MIC is showing active trend even in Japan. As for the research subjects of MIC, the example of corrosion promotion of carbon steel by sulfate reducing bacteria (SRB) in anaerobic environment is paid attention conventionally. Further, at present, effect of general type of aerobic heterotrophic bacteria on the corrosion of steel is paid attention and research is carried out actively. In this report, effect of aerobic heterotrophic bacteria on the corrosion of stainless steel is introduced focusing to the authors knowhow regarding the ennoblement phenomena of corrosion potential of stainless steel in natural sea water. 44 refs., 10 figs., 3 tabs.

  16. Microbial Community Profiling of Biodegradable Municipal Solid Waste Treatments : Aerobic Composting and Anaerobic Digestion

    OpenAIRE

    Yu, Dan

    2014-01-01

    An enormous quantity of solid waste is generated annually all over the world. Solid waste can be divided into three main categories: municipal waste, industrial waste and agricultural waste. The focus of the research presented in this thesis was on the biodegradable fraction of municipal solid waste (MSW), and particularly on the biowaste and sewage sludge generated in the Nordic countries. In general, there are two major options for processing biodegradable MSW in a sustainable manner: aerob...

  17. AKT-mediated enhanced aerobic glycolysis causes acquired radioresistance by human tumor cells

    International Nuclear Information System (INIS)

    Background and purpose: Cellular radioresistance is a major impediment to effective radiotherapy. Here, we demonstrated that long-term exposure to fractionated radiation conferred acquired radioresistance to tumor cells due to AKT-mediated enhanced aerobic glycolysis. Material and methods: Two human tumor cell lines with acquired radioresistance were established by long-term exposure to fractionated radiation with 0.5 Gy of X-rays. Glucose uptake was inhibited using 2-deoxy-D-glucose, a non-metabolizable glucose analog. Aerobic glycolysis was assessed by measuring lactate concentrations. Cells were then used for assays of ROS generation, survival, and cell death as assessed by annexin V staining. Results: Enhanced aerobic glycolysis was shown by increased glucose transporter Glut1 expression and a high lactate production rate in acquired radioresistant cells compared with parental cells. Inhibiting the AKT pathway using the AKT inhibitor API-2 abrogated these phenomena. Moreover, we found that inhibiting glycolysis with 2-deoxy-D-glucose suppressed acquired tumor cell radioresistance. Conclusions: Long-term fractionated radiation confers acquired radioresistance to tumor cells by AKT-mediated alterations in their glucose metabolic pathway. Thus, tumor cell metabolic pathway is an attractive target to eliminate radioresistant cells and improve radiotherapy efficacy

  18. Comparison of four enhancement strategies for aerobic granulation in sequencing batch reactors

    International Nuclear Information System (INIS)

    Aerobic granules were developed in four identical sequencing batch reactors (SBRs) with synthetic wastewater to compare different strategies for the enhancement of granulation. The SBRs were operated by (a) increasing organic loading rate in R1; (b) reducing settling time in R2; (c) extending starvation period in R3; and (d) increasing shear force in R4. The results showed that four operational strategies were able to enhance aerobic granulation successfully in SBR, but that also showed different effect on the granulation process and characteristics of mature aerobic granules. The rapidest granulation was observed by using short settling time (R2) and the granules had higher extracellular polymeric substance (EPS) than other reactors. Extended starvation period (R3) and high shear force (R4) resulted in longer granulation period and the granules with higher integrity and smaller size. Higher organic loading rate (R1) resulted in the granules with larger size and higher K value. The maximum specific COD removal rates (qmax) of the granules in all SBRs were at a similar level (0.13-0.16 g COD/h-g VSS) but the granules in R1 and R2 had higher apparent half rate constant (K) of 18 and 16 mg/L, than those in R3 and R4 (2.8 and 3.3 mg/L).

  19. Temperature-induced changes in treatment efficiency and microbial structure of aerobic granules treating landfill leachate.

    Science.gov (United States)

    Mieczkowski, Dorian; Cydzik-Kwiatkowska, Agnieszka; Rusanowska, Paulina; Świątczak, Piotr

    2016-06-01

    This paper investigates the effect of temperature on nitrogen and carbon removal by aerobic granules from landfill leachate with a high ammonium concentration and low concentration of biodegradable organics. The study was conducted in three stages; firstly the operating temperature of the batch reactor with aerobic granules was maintained at 29 °C, then at 25 °C, and finally at 20 °C. It was found that a gradual decrease in operational temperature allowed the nitrogen-converting community in the granules to acclimate, ensuring efficient nitrification even at ambient temperature (20 °C). Ammonium was fully removed from leachate regardless of the temperature, but higher operational temperatures resulted in higher ammonium removal rates [up to 44.2 mg/(L h) at 29 °C]. Lowering the operational temperature from 29 to 20 °C decreased nitrite accumulation in the GSBR cycle. The highest efficiency of total nitrogen removal was achieved at 25 °C (36.8 ± 10.9 %). The COD removal efficiency did not exceed 50 %. Granules constituted 77, 80 and 83 % of the biomass at 29, 25 and 20 °C, respectively. Ammonium was oxidized by both aerobic and anaerobic ammonium-oxidizing bacteria. Accumulibacter sp., Thauera sp., cultured Tetrasphaera PAO and Azoarcus-Thauera cluster occurred in granules independent of the temperature. Lower temperatures favored the occurrence of denitrifiers of Zooglea lineage (not Z. resiniphila), bacteria related to Comamonadaceae, Curvibacter sp., Azoarcus cluster, Rhodobacter sp., Roseobacter sp. and Acidovorax spp. At lower temperatures, the increased abundance of denitrifiers compensated for the lowered enzymatic activity of the biomass and ensured that nitrogen removal at 20 °C was similar to that at 25 °C and significantly higher than removal at 29 °C. PMID:27116957

  20. Microbial Enhanced Oil Recovery: 3D Simulation with Gravity Effects

    DEFF Research Database (Denmark)

    Nielsen, Sidsel Marie; Jessen, K.; Shapiro, Alexander;

    2010-01-01

    Microbial enhanced oil recovery (MEOR) utilizes the activity of microorganisms, where microorganisms simultaneously grow in a reservoir and convert substrate into recovery enhancing products (usually, surfactants). In order to predict the performance of a MEOR process, a simulation tool is requir...

  1. Aerobic biodegradation of natural and xenobiotic organic compounds by subsurface microbial communities

    International Nuclear Information System (INIS)

    Studies were conducted to characterize the diversity of degradative abilities of microbial communities from pristine aquifer solids samples. Biodegradation was measured in aquifer solids slurries as both the conversion of radiolabeled substrate to 14CO2 and the incorporation of label into cell biomass. The microbial community degraded aniline hydrochloride, chlorobenzene, p-chlorophenol, m-cresol, ethylene dibromide, naphthalene, phenol, toluene, and trichlorobenzene. Several kinetic parameters were calculated from the uptake and mineralization data. The results show that uptake into cell biomass represents a large fraction of total metabolism for many of the xenobiotic compounds

  2. Aerobic and anaerobic microbial activity in deep subsurface sediments from the Savannah River Plant

    International Nuclear Information System (INIS)

    Methanogenesis, sulfate reduction, and rates of carbon mineralization were determined for samples derived at different depths from four cores drilled at the Savannah River Plant, Aiken South Carolina. Three gram subsamples of the sediments were dispersed to 10-ml serum bottles under 5% H2 95% N2 and amended with 0.5 mL degassed distilled water with or without the following solutes: formate plus acetate, bicarbonate, lactate, and radiolabeled sulfate, glucose, and indole. After incubating 1 to 5 days, the sediments were assayed for methane, H2, 35S, and 14CO2. No methanogenesis was detected at any depth in any core and sulfate was rarely reduced. Evolution of 14CO2 from glucose and indole was detected in sediments as deep as 262 and 259 m, respectively. At some depths the 14CO2 evolution rate was comparable to that of surface soils; however, at other depths no 14CO2 evolution could be detected. Injection of sterile air into anaerobic incubations increased rates of carbon mineralization at all depths that had demonstrated anaerobic activity and stimulated mineralization activity in sediments that were inactive anaerobically, suggesting a predominance of aerobic metabolism. Increasing the concentration of added glucose and indole often increased the resulting rates of 14CO2 evolved from these substrates. The data indicate that both aerobic and anaerobic microorganisms are present and metabolically active in samples from deep subsurface environments. 16 refs., 3 figs

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

    Science.gov (United States)

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

    2016-01-01

    Mental and physical (MAP) training is a novel clinical intervention that combines mental training through meditation and physical training through aerobic exercise. The intervention was translated from neuroscientific studies indicating that MAP training increases neurogenesis in the adult brain. Each session consisted of 30 min of focused-attention (FA) meditation and 30 min of moderate-intensity aerobic exercise. Fifty-two participants completed the 8-week intervention, which consisted of two sessions per week. Following the intervention, individuals with major depressive disorder (MDD; n=22) reported significantly less depressive symptoms and ruminative thoughts. Typical healthy individuals (n=30) also reported less depressive symptoms at follow-up. Behavioral and event-related potential indices of cognitive control were collected at baseline and follow-up during a modified flanker task. Following MAP training, N2 and P3 component amplitudes increased relative to baseline, especially among individuals with MDD. These data indicate enhanced neural responses during the detection and resolution of conflicting stimuli. Although previous research has supported the individual beneficial effects of aerobic exercise and meditation for depression, these findings indicate that a combination of the two may be particularly effective in increasing cognitive control processes and decreasing ruminative thought patterns. PMID:26836414

  4. Improving phosphorus removal in aerobic granular sludge processes through selective microbial management.

    Science.gov (United States)

    Henriet, Olivier; Meunier, Christophe; Henry, Paul; Mahillon, Jacques

    2016-07-01

    This study aimed to improve phosphorus removal in aerobic granular sludge sequential batch reactors (AGS-SBR) by a differential selection of the granules containing the highest proportion of phosphate accumulating organisms (PAOs). The abundance of PAOs in granules with different density was analyzed by PCR-DGGE, pyrosequencing and qPCR. Dense granules contained a higher proportion of Candidatus Accumulibacter (PAO) with a 16S rRNA gene frequency up to 45%. Starting with an AGS-SBR with low height/diameter ratio performing unstable P removal, two strategies of biomass removal were assessed. First, a high selective pressure (short settling time) was applied and second, an increase of the settling time was combined with a homogeneous purge of the sludge bed. The first strategy resulted in a reduction of P removal efficiency while the second improved and stabilized P removal over 90%. This study offers a new approach of biomass management in AGS-SBR. PMID:27023385

  5. Enhanced degradation of 14C-HCB in two tropical clay soils using multiple anaerobic–aerobic cycles

    International Nuclear Information System (INIS)

    The aim of the study was to induce and enhance the degradation of hexachlorobenzene (HCB), a highly-chlorinated persistent organic pollutant, in two ecologically different tropical soils: a paddy soil (PS) and a non-paddy soil (FS). The degradation of HCB was enhanced using two anaerobic–aerobic cycles in model laboratory experiments. There was greater degradation of HCB in the PS (half-life of 224 days) relative to the FS (half-life of 286 days). It was further shown that soils amended with compost had higher metabolite concentrations relative to the non-amended soils. In the first cycle, there was little degradation of HCB in both soils. However, in the second cycle, there was enhanced mineralization in the PS under aerobic conditions, with the compost-treated samples showing higher mineralization. There was also extensive volatilization in both soils. The metabolite pattern revealed that the increased mineralization and volatilization was due to the formation of lower chlorinated benzenes. - Highlights: ► Two anaerobic–aerobic cycles enhanced the dissipation of HCB in two tropical soils – a paddy and non-paddy soil. ► The paddy soil was more effective in degrading HCB. ► The non-paddy soil adapted and degraded HCB in the second anaerobic–aerobic cycle. ► An additional carbon source enhanced degradation and mineralisation of HCB in both soils. - Two anaerobic–aerobic cycles enhance the degradation of HCB in two ecologically different tropical clay soils.

  6. Revival of microbial enhanced oil recovery (MEOR) initiatives on UK continental shelf

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, D.; Brealey, N. [Reservoir Management Ltd., Aberdeen (United Kingdom)

    2003-09-01

    This paper reviewed early activities of the Microbial Enhanced Oil Recovery (MEOR) initiative with particular reference to design and implementation of the MEOR project on the United Kingdom's continental shelf. Results of tests conducted in the 1980s and 1990s of the Biological Oil Stimulation process were ambiguous. A microbial flow diversion method was also being developed at that time to determine temperature profiles between injector and producer wells. The challenge for reservoir managers was the general lack of understanding on how a microbial treatment could affect flow within the reservoir at the microscopic and macroscopic level. There was also a need to model MEOR within a commercial reservoir. In 2001, Statoil announced the first field-wide offshore application of an aerobic MEOR technique with its development of the Norne field in the Norwegian sector of the North Sea. This prompted a rival and review of MEOR activity on the UK continental shelf. A workshop for UK operators was held to evaluate potential design characteristics and performance of MEOR using an adapted and commercially available reservoir simulator. New joint initiatives in the UK were also established. 12 refs., 12 figs.

  7. Theagalloflavic Acid, a New Pigment Derived from Hexahydroxydiphenoyl Group, and Lignan Oxidation Products Produced by Aerobic Microbial Fermentation of Green Tea.

    Science.gov (United States)

    Matsuo, Yosuke; Matsuda, Tomoko; Sugihara, Keisuke; Saito, Yoshinori; Zhang, Ying-Jun; Yang, Chong-Ren; Tanaka, Takashi

    2016-01-01

    Chinese ripe pu-erh tea is produced by aerobic microbial fermentation of green tea. To clarify the microbial degradation of tea polyphenols, Japanese commercial green tea was mixed with Chinese ripe pu-erh tea, which retains microorganisms, and fermented for 5 d. Chromatographic separation yielded a novel water-soluble yellow pigment termed theagalloflavic acid. Spectroscopic and chemical evidence suggested that this pigment was produced by oxidative ring cleavage of hexahydroxydiphenoyl esters. In addition, two new oxygenated lignin metabolites, (+)-5,5'-dihydroxypinoresinol and 5-hydroxydihydrodehydrodiconiferyl alcohol, were also isolated together with known degradation products of quercetin and tea catechins. PMID:27373646

  8. Strategies of aerobic microbial Fe acquisition from Fe-bearing montmorillonite clay

    Science.gov (United States)

    Kuhn, Keshia M.; DuBois, Jennifer L.; Maurice, Patricia A.

    2013-09-01

    This research investigated strategies used by the common aerobic soil bacterium Pseudomonas mendocina to acquire Fe associated with Fe(III)-bearing montmorillonite (MMT) clay. Given the known importance of Fe(III)-chelating siderophores, Fe-limited batch experiments were conducted using a wild-type (WT) strain that produces siderophores and a ΔpmhA mutant with a siderophore(-) phenotype. Growth measurements were coupled with a transcriptional biosensor assay that monitors the siderophore biosynthesis gene pmhA, measurements of cells' reducing ability, and quantification of exopolymeric substance (EPS) production. WT cells actively grow when MMT is the sole Fe source, but sorption to MMT may decrease the concentration of dissolved Fe-siderophore complex accessible to cells. Cells also obtain Fe by reducing MMT-associated Fe(III), but because P. mendocina lacks a secreted/diffusible reductant, direct physical contact is required. Dual strategies for Fe acquisition—a reducing mechanism that requires contact and that is likely facilitated by biofilm production and a siderophore related mechanism that does not require contact—provide flexibility to address the environmental Fe challenge.

  9. Photochemically enhanced microbial degradation of environmental pollutants

    International Nuclear Information System (INIS)

    Biodegradation of persistent halogenated organic pollutants is of great interest from the viewpoint of its potential use to cleanup the contaminated sites and industrial waste streams on-site (i.e., in situ remediation). Recent studies have shown that lignin-degrading white rot fungi possess capabilities to degrade a variety of highly recalcitrant and toxic compounds. On the other hand, photodegradation by sunlight or ultraviolet light (UV) has not been considered as a potential technology to detoxify the contaminated sites, in spite of the availability of extensive research data, because of its limited reaching ability to subsurface locations. In view of the urgent needs for the development of technology to deal with mounting problems of toxic wastes, the authors have decided to experiment with the ideas of combining photochemical and microbial technologies. The main obstacle in developing such simultaneous combination systems has been the susceptibilities of microorganisms in general to UV irradiation. To overcome this problem, the authors have developed an ultraviolet- and fungicide-resistant strain of white rot fungus and now report their results

  10. Enhancement of microbial degradation of hydrocarbons in soil and water

    International Nuclear Information System (INIS)

    A major focus in the biotechnology program at the Institute of Gas Technology (IGT) is to develop bioremediation processes for soil and water contaminated with hazaardous organic chemicals. Aerobic microbial cultures that have been developed in the past and anaerobic microbial cultures recently enriched for, are being used in a variety of ways to develop viable treatment strategies for these wastes. The authors have found that the chief factor limiting the rate and extent of PAH biodegradation in contaminated soil is mass transfer and when PAH's are rendered bioavailable in extensively. The most effective biodegradation is observed for polycyclic compounds of three- and fewer rings. Although not to as remarkable an extent, cultures are also able to decompose four, five and six ring PAH's. Studies with 14C-labelled PAH's haave revealed thaat two-, three-, four-, five-, and six-ring compounds can be completely mineralized with bacterial cultures or the white-rot fungus, Phanerochaete chrysosporium, either as pure reagent chemicals or in complex organic mixtures derived from contaminated town gas site soils. Continued scientific investigations must endeavor to overcome hazaardous waste mass transfer difficulties as an integral part of the development of practical treatment processes

  11. Biogas production enhancement using semi-aerobic pre-aeration in a hybrid bioreactor landfill.

    Science.gov (United States)

    Cossu, Raffaello; Morello, Luca; Raga, Roberto; Cerminara, Giulia

    2016-09-01

    Landfilling continues to be one of the main methods used in managing Municipal Solid Waste (MSW) worldwide, particularly in developing countries. Although in many countries national legislation aims to reduce this practice as much as possible, landfill is a necessary and unavoidable step in closing the material cycle. The need for innovative waste management techniques to improve landfill management and minimize the adverse environmental impact produced has resulted in an increasing interest in innovative systems capable of accelerating waste stabilization. Landfill bioreactors allow decomposition kinetics to be increased and post-operational phase to be shortened; in particular, hybrid bioreactors combine the benefits afforded by both aerobic and anaerobic processes. Six bioreactor simulators were used in the present study: four managed as hybrid, with an initial semi-aerobic phase and a second anaerobic phase, and two as anaerobic control bioreactors. The main goal of the first aerated phase is to reduce Volatile Fatty Acids (VFA) in order to increase pH and enhance methane production during the anaerobic phase; for this reason, air injection was stopped only when these parameters reached the optimum range for methanogenic bacteria. Biogas and leachate were constantly monitored throughout the entire methanogenic phase with the aim of calibrating a Gompertz Model and evaluating the effects of pre-aeration on subsequent methane production. The results showed that moderate and intermittent pre-aeration produces a positive effect both on methane potential and in the kinetics of reaction. PMID:26531047

  12. Bioturbation enhances the aerobic respiration of lake sediments in warming lakes.

    Science.gov (United States)

    Baranov, Viktor; Lewandowski, Jörg; Krause, Stefan

    2016-08-01

    While lakes occupy less than 2% of the total surface of the Earth, they play a substantial role in global biogeochemical cycles. For instance, shallow lakes are important sites of carbon metabolism. Aerobic respiration is one of the important drivers of the carbon metabolism in lakes. In this context, bioturbation impacts of benthic animals (biological reworking of sediment matrix and ventilation of the sediment) on sediment aerobic respiration have previously been underestimated. Biological activity is likely to change over the course of a year due to seasonal changes of water temperatures. This study uses microcosm experiments to investigate how the impact of bioturbation (by Diptera, Chironomidae larvae) on lake sediment respiration changes when temperatures increase. While at 5°C, respiration in sediments with and without chironomids did not differ, at 30°C sediment respiration in microcosms with 2000 chironomids per m(2) was 4.9 times higher than in uninhabited sediments. Our results indicate that lake water temperature increases could significantly enhance lake sediment respiration, which allows us to better understand seasonal changes in lake respiration and carbon metabolism as well as the potential impacts of global warming. PMID:27484649

  13. Gut Microbial Metabolite TMAO Enhances Platelet Hyperreactivity and Thrombosis Risk.

    Science.gov (United States)

    Zhu, Weifei; Gregory, Jill C; Org, Elin; Buffa, Jennifer A; Gupta, Nilaksh; Wang, Zeneng; Li, Lin; Fu, Xiaoming; Wu, Yuping; Mehrabian, Margarete; Sartor, R Balfour; McIntyre, Thomas M; Silverstein, Roy L; Tang, W H Wilson; DiDonato, Joseph A; Brown, J Mark; Lusis, Aldons J; Hazen, Stanley L

    2016-03-24

    Normal platelet function is critical to blood hemostasis and maintenance of a closed circulatory system. Heightened platelet reactivity, however, is associated with cardiometabolic diseases and enhanced potential for thrombotic events. We now show gut microbes, through generation of trimethylamine N-oxide (TMAO), directly contribute to platelet hyperreactivity and enhanced thrombosis potential. Plasma TMAO levels in subjects (n > 4,000) independently predicted incident (3 years) thrombosis (heart attack, stroke) risk. Direct exposure of platelets to TMAO enhanced sub-maximal stimulus-dependent platelet activation from multiple agonists through augmented Ca(2+) release from intracellular stores. Animal model studies employing dietary choline or TMAO, germ-free mice, and microbial transplantation collectively confirm a role for gut microbiota and TMAO in modulating platelet hyperresponsiveness and thrombosis potential and identify microbial taxa associated with plasma TMAO and thrombosis potential. Collectively, the present results reveal a previously unrecognized mechanistic link between specific dietary nutrients, gut microbes, platelet function, and thrombosis risk. PMID:26972052

  14. Experimental Studies of Microbial Enhanced Oil Recovery

    OpenAIRE

    Crescente, Christian Miguel

    2012-01-01

    The main purpose of this work was to understand the driving mechanisms by which the bacterium Rhodococcus sp. 094 increases oil recovery. The reason for only using this species was to thorougly investigate different aspects of it, to be able to answer as many questions as possible so that in the end it would be possible to confidently understand which mechanisms are responsible for enhanced oil recovery with this bacterium. From the lessons learned on this work one could more efficiently desi...

  15. Microbial dynamics and properties of aerobic granules developed in a laboratory-scale sequencing batch reactor with an intermediate filamentous bulking stage.

    Science.gov (United States)

    Aqeel, H; Basuvaraj, M; Hall, M; Neufeld, J D; Liss, S N

    2016-01-01

    Aerobic granules offer enhanced biological nutrient removal and are compact and dense structures resulting in efficient settling properties. Granule instability, however, is still a challenge as understanding of the drivers of instability is poorly understood. In this study, transient instability of aerobic granules, associated with filamentous outgrowth, was observed in laboratory-scale sequencing batch reactors (SBRs). The transient phase was followed by the formation of stable granules. Loosely bound, dispersed, and pinpoint seed flocs gradually turned into granular flocs within 60 days of SBR operation. In stage 1, the granular flocs were compact in structure and typically 0.2 mm in diameter, with excellent settling properties. Filaments appeared and dominated by stage 2, resulting in poor settleability. By stage 3, the SBRs were selected for larger granules and better settling structures, which included filaments that became enmeshed within the granule, eventually forming structures 2-5 mm in diameter. Corresponding changes in sludge volume index were observed that reflected changes in settleability. The protein-to-polysaccharide ratio in the extracted extracellular polymeric substance (EPS) from stage 1 and stage 3 granules was higher (2.8 and 5.7, respectively), as compared to stage 2 filamentous bulking (1.5). Confocal laser scanning microscopic (CLSM) imaging of the biomass samples, coupled with molecule-specific fluorescent staining, confirmed that protein was predominant in stage 1 and stage 3 granules. During stage 2 bulking, there was a decrease in live cells; dead cells predominated. Denaturing gradient gel electrophoresis (DGGE) fingerprint results indicated a shift in bacterial community composition during granulation, which was confirmed by 16S rRNA gene sequencing. In particular, Janthinobacterium (known denitrifier and producer of antimicrobial pigment) and Auxenochlorella protothecoides (mixotrophic green algae) were predominant during stage

  16. Acclimatization of microbial consortia to alkaline conditions and enhanced electricity generation.

    Science.gov (United States)

    Zhang, Enren; Zhai, Wenjing; Luo, Yue; Scott, Keith; Wang, Xu; Diao, Guowang

    2016-07-01

    Air-cathode microbial fuel cells (MFCs), obtained by inoculating with an aerobic activated sludge, were activated over a one month period, at pH 10.0, to obtain alkaline MFCs. The alkaline MFCs produced stable power of 118mWm(-2) and a maximum power density of 213mWm(-2) at pH 10.0, using glucose as substrate. The performance of the MFCs was enhanced to produce a stable power of 140mWm(-2) and a maximum power density of 235mWm(-2) by increasing pH to 11.0. This is the highest pH for stably operating MFCs reported in the literature. Power production was found to be suppressed at higher pH (12.0) and lower pH (9.0). Microbial analysis indicated that Firmicutes phylum was largely enriched in the anodic biofilms (88%), within which Eremococcus genus was the dominant group (47%). It is the first time that Eremococcus genus was described in bio-electrochemical systems. PMID:27061261

  17. Comprehensive microbial analysis of combined mesophilic anaerobic-thermophilic aerobic process treating high-strength food wastewater

    DEFF Research Database (Denmark)

    Jang, Hyun Min; Ha, Jeong Hyub; Park, Jong Moon;

    2015-01-01

    A combined mesophilic anaerobic-thermophilic aerobic process was used to treat high-strength food wastewater in this study. During the experimental period, most of solid residue from the mesophilic anaerobic reactor (R1) was separated by centrifugation and introduced into the thermophilic aerobic...

  18. Innovative treatment approaches in schizophrenia enhancing neuroplasticity: aerobic exercise, erythropoetin and repetitive transcranial magnetic stimulation.

    Science.gov (United States)

    Wobrock, T; Hasan, A; Falkai, P

    2012-06-01

    Schizophrenia is a brain disorder associated with subtle, but replicable cerebral volume loss mostly prevalent in frontal and temporal brain regions. Post-mortem studies of the hippocampus point to a reduction of the neuropil constituting mainly of synapses associated with changes of molecules mediating plastic responses of neurons during development and learning. Derived from animal studies interventions to enhance neuroplasticity by inducing adult neurogenesis, synaptogenesis, angiogenesis and long-term potentiation (LTP) were developed and the results translated into clinical studies in schizophrenia. Out of these interventions aerobic exercise has been shown to increase hippocampal volume, elevate N-acetyl-aspartate in the hippocampus as neuronal marker, and improve short-term memory in schizophrenia. The hematopoietic growth factor erythropoetin (EPO) is involved in brain development and associated with the production and differentiation of neuronal precursor cells. A first study demonstrated a positive effect of EPO application on cognition in schizophrenia patients. In randomised controlled studies with small sample size, the efficacy of repetitive transcranial magnetic stimulation (rTMS), a biological intervention focussing on the enhancement of LTP, has been shown for the improvement of positive and negative symptoms in schizophrenia,. The putative underlying neurobiological mechanisms of these interventions including the role of neurotrophic factors are outlined and implications for future research regarding neuroprotection strategies to improve schizophrenia are discussed. PMID:22283764

  19. Enhanced microbial reduction of vanadium (V) in groundwater with bioelectricity from microbial fuel cells

    Science.gov (United States)

    Hao, Liting; Zhang, Baogang; Tian, Caixing; Liu, Ye; Shi, Chunhong; Cheng, Ming; Feng, Chuanping

    2015-08-01

    Bioelectricity generated from the microbial fuel cell (MFC) is applied to the bioelectrical reactor (BER) directly to enhance microbial reduction of vanadium (V) (V(V)) in groundwater. With the maximum power density of 543.4 mW m-2 from the MFC, V(V) removal is accelerated with efficiency of 93.6% during 12 h operation. Higher applied voltage can facilitate this process. V(V) removals decrease with the increase of initial V(V) concentration, while extra addition of chemical oxygen demand (COD) has little effect on performance improvement. Microbial V(V) reduction is enhanced and then suppressed with the increase of conductivity. High-throughput 16S rRNA gene pyrosequencing analysis implies the accumulated Enterobacter and Lactococcus reduce V(V) with products from fermentative microorganisms such as Macellibacteroides. The presentation of electrochemically active bacteria as Enterobacter promotes electron transfers. This study indicates that application of bioelectricity from MFCs is a promising strategy to improve the efficiency of in-situ bioremediation of V(V) polluted groundwater.

  20. Microbial enhanced oil recovery and wettability research program

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, C.P.; Bala, G.A.; Duvall, M.L.

    1991-07-01

    This report covers research results for the microbial enhanced oil recovery (MEOR) and wettability research program conducted by EG G Idaho, Inc. at the Idaho National Engineering Laboratory (INEL). The isolation and characterization of microbial species collected from various locations including target oil field environments is underway to develop more effective oil recovery systems for specific applications. The wettability research is a multi-year collaborative effort with the New Mexico Petroleum Recovery Research Center (NMPRRC), to evaluate reservoir wettability and its effects on oil recovery. Results from the wettability research will be applied to determine if alteration of wettability is a significant contributing mechanism for MEOR systems. Eight facultatively anaerobic surfactant producing isolates able to function in the reservoir conditions of the Minnelusa A Sands of the Powder River Basin in Wyoming were isolated from naturally occurring oil-laden environments. Isolates were characterized according to morphology, thermostability, halotolerance, growth substrates, affinity to crude oil/brine interfaces, degradative effects on crude oils, and biochemical profiles. Research at the INEL has focused on the elucidation of microbial mechanisms by which crude oil may be recovered from a reservoir and the chemical and physical properties of the reservoir that may impact the effectiveness of MEOR. Bacillus licheniformis JF-2 (ATCC 39307) has been used as a benchmark organism to quantify MEOR of medium weight crude oils (17.5 to 38.1{degrees}API) the capacity for oil recovery of Bacillus licheniformis JF-2 utilizing a sucrose-based nutrient has been elucidated using Berea sandstone cores. Spacial distribution of cells after microbial flooding has been analyzed with scanning electron microscopy. Also the effect of microbial surfactants on the interfacial tensions (IFT) of aqueous/crude oil systems has been measured. 87 refs., 60 figs., 15 tabs.

  1. Response of aerobic granular sludge to the long-term presence to nanosilver in sequencing batch reactors: Reactor performance, sludge property, microbial activity and community

    Energy Technology Data Exchange (ETDEWEB)

    Quan, Xiangchun, E-mail: xchquan@bnu.edu.cn; Cen, Yan; Lu, Fang; Gu, Lingyun; Ma, Jingyun

    2015-02-15

    The increasing use of silver nanoparticles (Ag NPs) raises concerns about their potential toxic effects on the environment. Granular shape sludge is a special type of microbial aggregate. The response of aerobic granular sludge (AGS) to the long-term presence of Ag NPs has not been well studied. In this study, AGS was exposed to 5 and 50 mg/L Ag NPs in sequence batch reactors (SBRs) for 69 days, and its response was evaluated based on the sludge properties, microbial activity and community, and reactor performance. The results showed that Ag NPs caused inhibition to microbial activities of AGS from Day 35. At the end of 69 days of Ag NPs exposure, the microbial activity of AGS was significantly inhibited in terms of inhibitions of the ammonia oxidizing rate (33.0%), respiration rate (17.7% and 45.6%) and denitrification rate (6.8%), as well as decreases in the ammonia mono-oxygenase and nitrate reductase activities. During the long-term exposure, the AGS maintained its granular shape and large granule size (approximately 900 μm); the microbial community of AGS slightly changed, but the dominant microbial population remained. Overall, the AGS tolerated the toxicity of Ag NPs well, but a long-term exposure may produce chronic toxicity to the AGS, which is concerning. - Highlights: • AGS demonstrated a good tolerance to the long-term presence of Ag NPs. • Ag NPs did not produce acute toxicity but cause chronic toxicity to AGS. • AGS maintained granular shape, granule size and good settling ability. • The microbial community of AGS slightly changed after long-term Ag NPs exposure.

  2. Response of aerobic granular sludge to the long-term presence to nanosilver in sequencing batch reactors: Reactor performance, sludge property, microbial activity and community

    International Nuclear Information System (INIS)

    The increasing use of silver nanoparticles (Ag NPs) raises concerns about their potential toxic effects on the environment. Granular shape sludge is a special type of microbial aggregate. The response of aerobic granular sludge (AGS) to the long-term presence of Ag NPs has not been well studied. In this study, AGS was exposed to 5 and 50 mg/L Ag NPs in sequence batch reactors (SBRs) for 69 days, and its response was evaluated based on the sludge properties, microbial activity and community, and reactor performance. The results showed that Ag NPs caused inhibition to microbial activities of AGS from Day 35. At the end of 69 days of Ag NPs exposure, the microbial activity of AGS was significantly inhibited in terms of inhibitions of the ammonia oxidizing rate (33.0%), respiration rate (17.7% and 45.6%) and denitrification rate (6.8%), as well as decreases in the ammonia mono-oxygenase and nitrate reductase activities. During the long-term exposure, the AGS maintained its granular shape and large granule size (approximately 900 μm); the microbial community of AGS slightly changed, but the dominant microbial population remained. Overall, the AGS tolerated the toxicity of Ag NPs well, but a long-term exposure may produce chronic toxicity to the AGS, which is concerning. - Highlights: • AGS demonstrated a good tolerance to the long-term presence of Ag NPs. • Ag NPs did not produce acute toxicity but cause chronic toxicity to AGS. • AGS maintained granular shape, granule size and good settling ability. • The microbial community of AGS slightly changed after long-term Ag NPs exposure

  3. Treatment of colour industry wastewaters with concomitant bioelectricity production in a sequential stacked mono-chamber microbial fuel cells-aerobic system.

    Science.gov (United States)

    Fernando, Eustace; Keshavarz, Taj; Kyazze, Godfrey; Fonseka, Keerthi

    2016-01-01

    The scalability of any microbial fuel cell (MFC)-based system is of vital importance if it is to be utilized for potential field applications. In this study, an integrated MFC-aerobic bioreactor system was investigated for its scalability with the purpose of treating a simulated dye wastewater and industrial wastewaters originated from textile dyebaths and leather tanning. The influent containing real wastewater was fed into the reactor in continuous mode at ambient temperature. Three MFC units were integrated to act in unison as a single module for wastewater treatment and a continuously stirred aerobic bioreactor operating downstream to the MFC module was installed in order to ensure more complete degradation of colouring agents found in the wastewater. Total colour removal in the final effluent exceeded 90% in all experiments where both synthetic (AO-7 containing) and real wastewater were used as the influent feed. The chemical oxygen demand reduction also exceeded 80% in all experiments under the same conditions. The MFC modules connected in parallel configuration allowed obtaining higher current densities than that can be obtained from a single MFC unit. The maximum current density of the MFC stack reached 1150 mA m(-2) when connected in a parallel configuration. The outcome of this work implies that suitably up-scaled MFC-aerobic integrated bioprocesses could be used for colour industry wastewater treatment under industrially relevant conditions with possible prospects of bioelectricity generation. PMID:26212183

  4. An enhanced aerobic bioremediation system at a central production facility -- system design and data analysis

    International Nuclear Information System (INIS)

    A successful field demonstration of the enhanced in-situ aerobic bioremediation with remarkable results took place during the period of August 1, 1991 through year-end 1992 at a central production facility in Michigan. The in-situ soil logging and groundwater sampling by the cone penetrometer/porous probe system provided a real-time definition of the groundwater flow ''channel'' and a clear delineation of the plume extent. That facilitated the design of the closed-loop bioremediation system, consisting of two downgradient pumping wells to completely capture the plume and two pairs of bi-level injection wells located upgradient of the plume. The purged groundwater from the two pumping wells after amending with dissolved oxygen is directly reinjected to the two pairs of upgradient bi-level injection wells. In addition, the performance of the system is monitored by 17 multilevel piezometers. Each piezometer consists of four vertical sampling levels, providing a total of 68 sampling points to fully define the three-dimensional characteristics of the BTEX and DO plumes. Based on a hydrograph analysis of the groundwater data, the closed-loop bioremediation system has been operating properly. In addition, a particle tracking analysis showed groundwater flowlines converge to the pumping wells demonstrating the effectiveness of the plume capture. The trend analysis showed a consistent decline of BTEX concentrations at all of the 68 sampling points

  5. In situ microbial systems for the enhancement of oil recovery

    International Nuclear Information System (INIS)

    Microbial Enhancement of Oil Recovery (MEOR) offers important new opportunities in the quest for increased oil production. It refers not to a single technique but rather to a collection of methodologies, analogous to parallel non-microbiological methods. MEOR has relevance for many type of production and reservoir problems detailed protocols: may be tailored specifically to a range of individual reservoir conditions. Microorganisms downhole can generate a wide variety of chemical products from inexpensive feed stocks: where these are more cost-effective than oil field chemicals injected from the surface, microbial methods may win widespread acceptance. MEOR methods must be defined precisely; in any particular reservoir procedure their proposed mechanism of action must be clearly understood and criteria established for evaluating their success. The most important applications for MEOR are 1) the production f insoluble or highly viscous polymer to control coning or to plug selectively high permeability thief zones and fractures, 2) the continuous generation of the active agents for polymer-and/or surfactant floods, 3) matrix acidisation and acid fracturing in carbonate rocks stimulate flows into production wells. All these approaches are currently actively been explored; several programmes for field-testing microbial EOR methods already exist, or are being readied, and rapid progress is likely within the next few years. (author)

  6. Impact of nitrite on aerobic phosphorus uptake by poly-phosphate accumulating organisms in enhanced biological phosphorus removal sludges.

    Science.gov (United States)

    Zeng, Wei; Li, Boxiao; Yang, Yingying; Wang, Xiangdong; Li, Lei; Peng, Yongzhen

    2014-02-01

    Impact of nitrite on aerobic phosphorus (P) uptake of poly-phosphate accumulating organisms (PAOs) in three different enhanced biological phosphorus removal (EBPR) systems was investigated, i.e., the enriched PAOs culture fed with synthetic wastewater, the two lab-scale sequencing batch reactors (SBRs) treating domestic wastewater for nutrient removal through nitrite-pathway nitritation and nitrate-pathway nitrification, respectively. Fluorescence in situ hybridization results showed that PAOs in the three sludges accounted for 72, 7.6 and 6.5% of bacteria, respectively. In the enriched PAOs culture, at free nitrous acid (FNA) concentration of 0.47 × 10(-3) mg HNO₂-N/L, aerobic P-uptake and oxidation of intercellular poly-β-hydroxyalkanoates were both inhibited. Denitrifying phosphorus removal under the aerobic conditions was observed, indicating the existence of PAOs using nitrite as electron acceptor in this culture. When the FNA concentration reached 2.25 × 10(-3) mg HNO2-N/L, denitrifying phosphorus removal was also inhibited. And the inhibition ceased once nitrite was exhausted. Corresponding to both SBRs treating domestic wastewater with nitritation and nitrification pathway, nitrite inhibition on aerobic P-uptake by PAOs did not occur even though FNA concentration reached 3 × 10(-3) and 2.13 × 10(-3) mg HNO₂-N/L, respectively. Therefore, PAOs taken from different EBPR activated sludges had different tolerance to nitrite. PMID:23771179

  7. Benzoate-induced stress enhances xylitol yield in aerobic fed-batch culture of Candida mogii TISTR 5892.

    Science.gov (United States)

    Wannawilai, Siwaporn; Sirisansaneeyakul, Sarote; Chisti, Yusuf

    2015-01-20

    Production of the natural sweetener xylitol from xylose via the yeast Candida mogii TISTR 5892 was compared with and without the growth inhibitor sodium benzoate in the culture medium. Sodium benzoate proved to be an uncompetitive inhibitor in relatively poorly oxygenated shake flask aerobic cultures. In a better controlled aerobic environment of a bioreactor, the role of sodium benzoate could equally well be described as competitive, uncompetitive or noncompetitive inhibitor of growth. In intermittent fed-batch fermentations under highly aerobic conditions, the presence of sodium benzoate at 0.15gL(-1) clearly enhanced the xylitol titer relative to the control culture without the sodium benzoate. The final xylitol concentration and the average xylitol yield on xylose were nearly 50gL(-1) and 0.57gg(-1), respectively, in the presence of sodium benzoate. Both these values were substantially higher than reported for the same fermentation under microaerobic conditions. Therefore, a fed-batch aerobic fermentation in the presence of sodium benzoate is promising for xylitol production using C. mogii. PMID:25499077

  8. Acute aerobic exercise enhances attentional modulation of somatosensory event-related potentials during a tactile discrimination task.

    Science.gov (United States)

    Popovich, Christina; Staines, W Richard

    2015-03-15

    Neuroimaging research has shown that acute bouts of moderate intensity aerobic exercise can enhance attention-based neuronal activity in frontal brain regions, namely in the prefrontal cortex (PFC), as well as improve cognitive performance. The circuitry of the PFC is complex with extensive reciprocal corticocortical and thalamocortical connections, yet it remains unclear if aerobic exercise can also assist attentional control over modality-specific sensory cortices. To test this, we used a tactile discrimination task to compare tactile event-related potentials (ERPs) prior to and following an acute bout of moderate intensity aerobic exercise. We hypothesized that exercise preceding performance of the task would result in more efficient sensory gating of irrelevant/non-attended and enhancement of relevant/attended sensory information, respectively. Participants received vibrotactile stimulation to the second and fifth digit on the left hand and reported target stimuli on one digit only. ERP amplitudes for the P50, P100, N140 and long latency positivity (LLP) were quantified for attended and non-attended trials at FC4, C4, CP4 and P4 while P300 amplitudes were quantified in response to attended target stimuli at electrodes FCZ, CZ and CPZ. Results showed no effect of attention on the P50, however, both P100 and LLP amplitudes were significantly greater during attended, task-relevant trials, while the N140 was enhanced for non-attended, task-irrelevant stimuli. Moreover, unattended N140 amplitudes over parietal sites contralateral to stimulation were significantly greater post-exercise versus pre-exercise, while LLP modulation varied with greater unattended amplitudes post-exercise over frontal sites and greater attended amplitudes post-exercise over parietal sites. These results suggest that a single session of moderate intensity aerobic exercise facilitated the sensory gating of task-irrelevant tactile stimuli so that relevant sensory signals could be enhanced at

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

    OpenAIRE

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

    2016-01-01

    Mental and physical (MAP) training is a novel clinical intervention that combines mental training through meditation and physical training through aerobic exercise. The intervention was translated from neuroscientific studies indicating that MAP training increases neurogenesis in the adult brain. Each session consisted of 30 min of focused-attention (FA) meditation and 30 min of moderate-intensity aerobic exercise. Fifty-two participants completed the 8-week intervention, which consisted of t...

  10. Microbial based strategies for assessing rhizosphere-enhanced phytoremediation

    International Nuclear Information System (INIS)

    The U.S. Department of Defense has considered phytoremediation to be a feasible technology to clean up contaminated sites in remote, cold regions. In cold regions, contaminated soil treatment rates are reduced by low temperatures and short treatment seasons. One technology that overcomes these limitations is rhizosphere-enhanced biotreatment which is a low-cost, simple technology that stimulates indigenous microorganisms. A study was conducted in which rhizosphere-enhanced treatment was compared to natural attenuation at a petroleum-contaminated site in Fairbanks, Alaska. The effects of vegetation and nutrient additions on remediation of soils contaminated with both diesel and crude oil were examined. Soil total petroleum hydrocarbon (TPH) concentrations in both treatments decreased relative to the initial TPH concentrations. After 640 days of treatment, the rhizosphere treatment had significantly lower TPH concentrations. It was concluded that an improved understanding of the time-dependent relationships between contaminant concentration changes and microbial community changes, along with improved techniques to characterize microbial communities, could provide a useful tool for monitoring the functioning of phytoremediation. 25 refs., 8 figs

  11. Microbial community structure and diversity in an integrated system of anaerobic-aerobic reactors and a constructed wetland for the treatment of tannery wastewater in Modjo, Ethiopia.

    Directory of Open Access Journals (Sweden)

    Adey Feleke Desta

    Full Text Available A culture-independent approach was used to elucidate the microbial diversity and structure in the anaerobic-aerobic reactors integrated with a constructed wetland for the treatment of tannery wastewater in Modjo town, Ethiopia. The system has been running with removal efficiencies ranging from 94%-96% for COD, 91%-100% for SO4(2- and S(2-, 92%-94% for BOD, 56%-82% for total Nitrogen and 2%-90% for NH3-N. 16S rRNA gene clone libraries were constructed and microbial community assemblies were determined by analysis of a total of 801 unique clone sequences from all the sites. Operational Taxonomic Unit (OTU--based analysis of the sequences revealed highly diverse communities in each of the reactors and the constructed wetland. A total of 32 phylotypes were identified with the dominant members affiliated to Clostridia (33%, Betaproteobacteria (10%, Bacteroidia (10%, Deltaproteobacteria (9% and Gammaproteobacteria (6%. Sequences affiliated to the class Clostridia were the most abundant across all sites. The 801 sequences were assigned to 255 OTUs, of which 3 OTUs were shared among the clone libraries from all sites. The shared OTUs comprised 80 sequences belonging to Clostridiales Family XIII Incertae Sedis, Bacteroidetes and unclassified bacterial group. Significantly different communities were harbored by the anaerobic, aerobic and rhizosphere sites of the constructed wetland. Numerous representative genera of the dominant bacterial classes obtained from the different sample sites of the integrated system have been implicated in the removal of various carbon- containing pollutants of natural and synthetic origins. To our knowledge, this is the first report of microbial community structure in tannery wastewater treatment plant from Ethiopia.

  12. Application of high OLR-fed aerobic granules for the treatment of low-strength wastewater: performance, granule morphology and microbial community.

    Science.gov (United States)

    Ma, Jingyun; Quan, Xiangchun; Li, Huai

    2013-08-01

    Aerobic granules, pre-cultivated at the organic loading rate (OLR) of 3.0 kg COD/(m3 x day), were used to treat low-strength wastewater in two sequencing batch reactors at low OLRs of 1.2 and 0.6 kg COD/(m3 x day), respectively. Reactor performance, evolution of granule morphology, structure and microbial community at low OLRs under long-term operation (130 days) were investigated. Results showed that low OLRs did not cause significant damage to granule structure as a dominant granule morphology with size over 540 microm was maintained throughout the operation. Aerobic granules at sizes of about 750 microm were finally obtained at the low OLRs. The granule reactors operated at low OLRs demonstrated effective COD and ammonia removals (above 90%), smaller granule sizes and less biomass. The contents of extracellular polymeric substances in the granules were decreased while the ratios of exopolysaccharide/exoprotein were increased (above 1.0). The granules cultivated at the low OLRs showed a smoother surface and more compact structure than the seeded granules. A significant shift in microbial community was observed but the microbial diversity remained relatively stable. Confocal Laser Scanning Microscopy observation showed that the live cells were spread throughout the whole granule, while the dead cells were mainly concentrated in the outer layer of the granule, and the proteins, polysaccharides and lipids were mainly located in the central regime of the granule. In conclusion, granules cultivated at high OLRs show potential for treating low-strength organic wastewater steadily under long-term operation. PMID:24520692

  13. Microbial Community Structure and Diversity in an Integrated System of Anaerobic-Aerobic Reactors and a Constructed Wetland for the Treatment of Tannery Wastewater in Modjo, Ethiopia

    Science.gov (United States)

    Desta, Adey Feleke; Assefa, Fassil; Leta, Seyoum; Stomeo, Francesca; Wamalwa, Mark; Njahira, Moses; Appolinaire, Djikeng

    2014-01-01

    A culture-independent approach was used to elucidate the microbial diversity and structure in the anaerobic-aerobic reactors integrated with a constructed wetland for the treatment of tannery wastewater in Modjo town, Ethiopia. The system has been running with removal efficiencies ranging from 94%–96% for COD, 91%–100% for SO42- and S2-, 92%–94% for BOD, 56%–82% for total Nitrogen and 2%–90% for NH3-N. 16S rRNA gene clone libraries were constructed and microbial community assemblies were determined by analysis of a total of 801 unique clone sequences from all the sites. Operational Taxonomic Unit (OTU) - based analysis of the sequences revealed highly diverse communities in each of the reactors and the constructed wetland. A total of 32 phylotypes were identified with the dominant members affiliated to Clostridia (33%), Betaproteobacteria (10%), Bacteroidia (10%), Deltaproteobacteria (9%) and Gammaproteobacteria (6%). Sequences affiliated to the class Clostridia were the most abundant across all sites. The 801 sequences were assigned to 255 OTUs, of which 3 OTUs were shared among the clone libraries from all sites. The shared OTUs comprised 80 sequences belonging to Clostridiales Family XIII Incertae Sedis, Bacteroidetes and unclassified bacterial group. Significantly different communities were harbored by the anaerobic, aerobic and rhizosphere sites of the constructed wetland. Numerous representative genera of the dominant bacterial classes obtained from the different sample sites of the integrated system have been implicated in the removal of various carbon- containing pollutants of natural and synthetic origins. To our knowledge, this is the first report of microbial community structure in tannery wastewater treatment plant from Ethiopia. PMID:25541981

  14. Investigations in the microbial degradation of polychlorinated dibenzo-p-dioxins and means of reductive dechlorination and aerobic mineralization

    International Nuclear Information System (INIS)

    The work had the objective to develop a biological method for cleaning up PCDD/PCDF contaminated upper soil layers (PCDDs/PCDFs: polychlorinated dibenzo-p-dioxins and dibenzofurans). Since highly chlorinated aromatic compounds persist in soil under aerobic conditions, reductive dechlorination of the compounds under anaerobic conditions was aimed at in a first phase of the project. A second, topped phase was destined for aerobic mineralization of the dechlorinated matrices. The tests were carried out on three farmland soils following long-term contamination with PCDDs/PCDFs. (orig./MG)

  15. Microbial processes in the Athabasca Oil Sands and their potential applications in microbial enhanced oil recovery.

    Science.gov (United States)

    Harner, N K; Richardson, T L; Thompson, K A; Best, R J; Best, A S; Trevors, J T

    2011-11-01

    The Athabasca Oil Sands are located within the Western Canadian Sedimentary Basin, which covers over 140,200 km(2) of land in Alberta, Canada. The oil sands provide a unique environment for bacteria as a result of the stressors of low water availability and high hydrocarbon concentrations. Understanding the mechanisms bacteria use to tolerate these stresses may aid in our understanding of how hydrocarbon degradation has occurred over geological time, and how these processes and related tolerance mechanisms may be used in biotechnology applications such as microbial enhanced oil recovery (MEOR). The majority of research has focused on microbiology processes in oil reservoirs and oilfields; as such there is a paucity of information specific to oil sands. By studying microbial processes in oil sands there is the potential to use microbes in MEOR applications. This article reviews the microbiology of the Athabasca Oil Sands and the mechanisms bacteria use to tolerate low water and high hydrocarbon availability in oil reservoirs and oilfields, and potential applications in MEOR. PMID:21853326

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

    Science.gov (United States)

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

    2016-07-01

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

  17. Microbial enhancement of oil recovery: Recent advances. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Premuzic, E.T.; Woodhead, A.D.; Vivirito, K.J. [eds.

    1992-12-31

    During recent years, systematic, scientific, and engineering effort by researchers in the United States and abroad, has established the scientific basis for Microbial Enhanced Oil Recovery (MEOR) technology. The successful application of MEOR technology as an oil recovery process is a goal of the Department of Energy (DOE). Research efforts involving aspects of MEOR in the microbiological, biochemical, and engineering fields led DOE to sponsor an International Conference at Brookhaven National Laboratory in 1992, to facilitate the exchange of information and a discussion of ideas for the future research emphasis. At this, the Fourth International MEOR Conference, where international attendees from 12 countries presented a total of 35 papers, participants saw an equal distribution between ``research`` and ``field applications.`` In addition, several modeling and ``state-of-the-art`` presentations summed up the present status of MEOR science and engineering. Individual papers in this proceedings have been process separately for inclusion in the Energy Science and Technology Database.

  18. Simulations of Microbial-Enhanced Oil Recovery: Adsorption and Filtration

    DEFF Research Database (Denmark)

    Nielsen, Sidsel Marie; Nesterov, Igor; Shapiro, Alexander

    2014-01-01

    introduced to study the process efficiency: the dimensionless time at which average recovery between pure water injection and maximum surfactant effect is reached. This characteristic recovery period (CRP) was studied as a function of the different MEOR parameters such as bacterial activity, filtration......In the context of microbial-enhanced oil recovery (MEOR) with injection of surfactant-producing bacteria into the reservoir, different types of bacteria attachment and growth scenarios are studied using a 1D simulator. The irreversible bacteria attachment due to filtration similar to the deep bed...... applied to filtration model provides formation of two oil banks during recovery. This feature is not reproduced by application of REA model or DBF with growth in attached phase. This makes it possible to select a right model based on the qualitative analysis of the experimental data. A criterion is...

  19. How Specific Microbial Communities Benefit the Oil Industry: Microbial-Enhanced Oil Recovery (MEOR)

    Science.gov (United States)

    Rudyk, Svetlana; Søgaard, Erik

    Microbial-enhanced oil recovery (MEOR) involves injecting into the oil-saturated layer microbes and/nutrients to create the in situ production of metabolic products or nutrients to stimulate indigenous microbes. The purposes of MEOR are to increase oil production, decrease the water cut and prolong the productive life of the oilfield. The most probable targets of MEOR are reservoirs that have reached the limits of oil production by injection of water to displace oil (Donaldson and Obeida, 1991). MEOR is the cheapest approach of oil recovery after water flooding. MEOR investigations have been conducted all over the world and resulted in many successful field applications in the USA, UK, China, Russia, Malaysia, Germany, Romania, Poland and others.

  20. Carbon fiber enhanced bioelectricity generation in soil microbial fuel cells.

    Science.gov (United States)

    Li, Xiaojing; Wang, Xin; Zhao, Qian; Wan, Lili; Li, Yongtao; Zhou, Qixing

    2016-11-15

    The soil microbial fuel cell (MFC) is a promising biotechnology for the bioelectricity recovery as well as the remediation of organics contaminated soil. However, the electricity production and the remediation efficiency of soil MFC are seriously limited by the tremendous internal resistance of soil. Conductive carbon fiber was mixed with petroleum hydrocarbons contaminated soil and significantly enhanced the performance of soil MFC. The maximum current density, the maximum power density and the accumulated charge output of MFC mixed carbon fiber (MC) were 10, 22 and 16 times as high as those of closed circuit control due to the carbon fiber productively assisted the anode to collect the electron. The internal resistance of MC reduced by 58%, 83% of which owed to the charge transfer resistance, resulting in a high efficiency of electron transfer from soil to anode. The degradation rates of total petroleum hydrocarbons enhanced by 100% and 329% compared to closed and opened circuit controls without the carbon fiber respectively. The effective range of remediation and the bioelectricity recovery was extended from 6 to 20cm with the same area of air-cathode. The mixed carbon fiber apparently enhanced the bioelectricity generation and the remediation efficiency of soil MFC by means of promoting the electron transfer rate from soil to anode. The use of conductively functional materials (e.g. carbon fiber) is very meaningful for the remediation and bioelectricity recovery in the bioelectrochemical remediation. PMID:27162144

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Chao Wei

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

  3. Enhancement of aerobic biodegradation in an oxygen-limiting environment using a saponin-based microbubble suspension

    International Nuclear Information System (INIS)

    This study investigated the ability of a saponin-based microbubble suspension to enhance aerobic biodegradation of phenanthrene by subsurface delivery. As the microbubble suspension flowed through a sand column pressure buildup and release was repeatedly observed, which delivered oxygen to the less permeable regions. Burkholderia cepacia RPH1, a phenanthrene-degrading bacterium, was mainly transported in a suspended form in the microbubble suspension. When three pore volumes of the microbubble suspension containing B. cepacia RPH1 was introduced into a column contaminated with phenanthrene (100 mg/kg), the oxygen content declined to 5% from an initial value of 20% within 5 days and correspondingly, 34.4% of initial phenanthrene was removed in 8 days. The addition of two further three pore volumes enhanced the biodegradation efficiency by a factor of 2.2. Our data suggest that a saponin-based microbubble suspension could be a potential carrier for enhancing the aerobic biodegradation under an oxygen-limiting environment. - Microbubble suspension can enhance the phenanthrene biodegradation under an oxygen-limiting condition.

  4. Enhancement of aerobic biodegradation in an oxygen-limiting environment using a saponin-based microbubble suspension

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong Ju; Kim, Young-Jin [Department of Civil and Environmental Engineering, Seoul National University, Shillim-dong, Gwanak-gu, Seoul (Korea, Republic of); Nam, Kyoungphile, E-mail: kpnam@snu.ac.k [Department of Civil and Environmental Engineering, Seoul National University, Shillim-dong, Gwanak-gu, Seoul (Korea, Republic of)

    2009-08-15

    This study investigated the ability of a saponin-based microbubble suspension to enhance aerobic biodegradation of phenanthrene by subsurface delivery. As the microbubble suspension flowed through a sand column pressure buildup and release was repeatedly observed, which delivered oxygen to the less permeable regions. Burkholderia cepacia RPH1, a phenanthrene-degrading bacterium, was mainly transported in a suspended form in the microbubble suspension. When three pore volumes of the microbubble suspension containing B. cepacia RPH1 was introduced into a column contaminated with phenanthrene (100 mg/kg), the oxygen content declined to 5% from an initial value of 20% within 5 days and correspondingly, 34.4% of initial phenanthrene was removed in 8 days. The addition of two further three pore volumes enhanced the biodegradation efficiency by a factor of 2.2. Our data suggest that a saponin-based microbubble suspension could be a potential carrier for enhancing the aerobic biodegradation under an oxygen-limiting environment. - Microbubble suspension can enhance the phenanthrene biodegradation under an oxygen-limiting condition.

  5. Microbial surfactant-enhanced mineral oil recovery under laboratory conditions.

    Science.gov (United States)

    Bordoloi, N K; Konwar, B K

    2008-05-01

    Microbial enhanced oil recovery (MEOR) is potentially useful to recover incremental oil from a reservoir being beyond primary and secondary recovery operations. Effort has been made to isolate and characterize natural biosurfactant produced by bacterial isolates collected from various oil fields of ONGC in Assam. Production of biosurfactant has been considered to be an effective major index for the purpose of enhanced oil recovery. On the basis of the index, four promising bacterial isolates: Pseudomonas aeruginosa (MTCC7815), P. aeruginosa (MTCC7814), P. aeruginosa (MTCC7812) and P. aeruginosa (MTCC8165) were selected for subsequent testing. Biosurfactant produced by the promising bacterial isolates have been found to be effective in the recovery of crude oil from saturated column under laboratory conditions. Two bacterial strains: P. aeruginosa (MTCC7815) and P. aeruginosa (MTCC7812) have been found to be the highest producer of biosurfactant. Tensiometer studies revealed that biosurfactants produced by these bacterial strains could reduce the surface tension (sigma) of the growth medium from 68 to 30 mN m(-1) after 96 h of growth. The bacterial biosurfactants were found to be functionally stable at varying pH (2.5-11) conditions and temperature of 100 degrees C. The treatment of biosurfactant containing, cell free culture broth in crude oil saturated sand pack column could release about 15% more crude oil at 90 degrees C than at room temperature and 10% more than at 70 degrees C under laboratory condition. PMID:18164187

  6. Repeated Bouts of Aerobic Exercise Enhance Regulatory T Cell Responses in a Murine Asthma Model

    OpenAIRE

    Lowder, Thomas; Dugger, Kari; Deshane, Jessy; Estell, Kim; Schwiebert, Lisa M

    2009-01-01

    We have reported previously that moderate intensity aerobic exercise training attenuates airway inflammation in a murine asthma model. Recent studies implicate regulatory T (Treg) cells in decreasing asthma-related airway inflammation; as such, the current study examined the effect of exercise on Treg cell function in a murine asthma model. Mice were sensitized with ovalbumin (OVA) prior to the start of exercise training at a moderate intensity 3× / week for 4 wks; exercise was performed as t...

  7. Screening of microorganisms for microbial enhanced oil recovery processes

    Energy Technology Data Exchange (ETDEWEB)

    Yonebayashi, H. [Japan National Oil Corp., Tokyo (Japan); Yoshida, S. [Japan Food Research Laboratiories, Tokyo (Japan). Div. of Microbiology; Ono, K. [Japan National Oil Corp., Chiba (Japan). Tech. Research Center; Enomoto, H. [Tohoku University, Sendai (Japan). Dept. of Geoscience and Tech.

    2000-01-01

    The objective of this study is to screen effective microorganisms for the Microbial Enhanced Oil Recovery process (or simply as MEOR). Samples of drilling cuttings, formation water, and soil were collected from domestic drilling sites and oil fields. Moreover, samples of activated-sludge and compost were collected from domestic sewage treatment facility and food treatment facility. At first, microorganisms in samples were investigated by incubation with different media; then they were isolated. By two stage-screening based on metabolizing ability, 4 strains (Bacillus licheniformis TRC-18-2-a, Enterobacter cloacae TRC-322, Bacillus subtilis TRC-4118, and Bacillus subtilis TRC-4126) were isolated as effective microorganisms for oil recovery. B. licheniformis TRC-18-2-a is a multifunctional microorganism possessing excellent surfactant productivity, and in addition it has gas, acid and polymer productivities. E. cloacae TRC-332 has gas and acid producing abilities. B. subtilis TRC-4118 and TRC-4126 are effective biosurfactant producers, and they reduce the interfacial tension to 0.04 and 0.12 dyne/cm, respectively. (author)

  8. Microbial enhanced oil recovery research. Final report, Annex 5

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, M.M.; Gerogiou, G.

    1993-07-01

    The objective of this project was to develop an engineering framework for the exploitation of microorganisms to enhance oil recovery. An order of magnitude analysis indicated that selective plugging and the production of biosurfactants are the two most likely mechanisms for the mobilization of oil in microbial enhanced oil recovery (MEOR). The latter, biosurfactant production, is easier to control within a reservoir environment and was investigated in some detail. An extensive literature survey indicated that the bacterium Bacillus licheniformis JF-2 produces a very effective surface active agent capable of increasing the capillary number to values sufficiently low for oil mobilization. In addition, earlier studies had shown that growth of this bacterium and biosurfactant production occur under conditions that are typically encountered in MEOR, namely temperatures up to 55{degrees}C, lack of oxygen and salinities of up to 10% w/v. The chemical structure of the surfactant, its interfacial properties and its production by fermentation were characterized in some detail. In parallel, a set of experiments as conducted to measure the transport of Bacillus licheniformis JF-2 in sandpacks. It was shown that the determining parameters for cell transport in porous media are: cell size and degree of coagulation, presence of dispersants, injection velocity and cell concentration. The mechanisms of bacteria retention within the pores of the reservoir were analyzed based on heuristic arguments. A mathematical simulator of MEOR was developed using conservation equations in which the mechanisms of bacteria retention and the growth kinetics of the cells were incorporated. The predictions of the model agreed reasonably well with experimental results.

  9. Development of a predictive model for the growth kinetics of aerobic microbial population on pomegranate marinated chicken breast fillets under isothermal and dynamic temperature conditions.

    Science.gov (United States)

    Lytou, Anastasia; Panagou, Efstathios Z; Nychas, George-John E

    2016-05-01

    The aim of this study was the development of a model to describe the growth kinetics of aerobic microbial population of chicken breast fillets marinated in pomegranate juice under isothermal and dynamic temperature conditions. Moreover, the effect of pomegranate juice on the extension of the shelf life of the product was investigated. Samples (10 g) of chicken breast fillets were immersed in marinades containing pomegranate juice for 3 h at 4 °C following storage under aerobic conditions at 4, 10, and 15 °C for 10 days. Total Viable Counts (TVC), Pseudomonas spp and lactic acid bacteria (LAB) were enumerated, in parallel with sensory assessment (odor and overall appearance) of marinated and non-marinated samples. The Baranyi model was fitted to the growth data of TVC to calculate the maximum specific growth rate (μmax) that was further modeled as a function of temperature using a square root-type model. The validation of the model was conducted under dynamic temperature conditions based on two fluctuating temperature scenarios with periodic changes from 6 to 13 °C. The shelf life was determined both mathematically and with sensory assessment and its temperature dependence was modeled by an Arrhenius type equation. Results showed that the μmax of TVC of marinated samples was significantly lower compared to control samples regardless temperature, while under dynamic temperature conditions the model satisfactorily predicted the growth of TVC in both control and marinated samples. The shelf-life of marinated samples was significantly extended compared to the control (5 days extension at 4 °C). The calculated activation energies (Ea), 82 and 52 kJ/mol for control and marinated samples, respectively, indicated higher temperature dependence of the shelf life of control samples compared to marinated ones. The present results indicated that pomegranate juice could be used as an alternative ingredient in marinades to prolong the shelf life of chicken. PMID:26742613

  10. Strain-resolved microbial community proteomics reveals simultaneous aerobic and anaerobic function during gastrointestinal tract colonization of a preterm infant

    Directory of Open Access Journals (Sweden)

    Brandon eBrooks

    2015-07-01

    Full Text Available While there has been growing interest in the gut microbiome in recent years, it remains unclear whether closely related species and strains have similar or distinct functional roles and if organisms capable of both aerobic and anaerobic growth do so simultaneously. To investigate these questions, we implemented a high-throughput mass spectrometry-based proteomics approach to identify proteins in fecal samples collected on days of life 13-21 from an infant born at 28 weeks gestation. No prior studies have coupled strain-resolved community metagenomics to proteomics for such a purpose. Sequences were manually curated to resolve the genomes of two strains of Citrobacter that were present during the later stage of colonization. Proteome extracts from fecal samples were processed via a nano-2D-LC-MS/MS and peptides were identified based on information predicted from the genome sequences for the dominant organisms, Serratia and the two Citrobacter strains. These organisms are facultative anaerobes, and proteomic information indicates the utilization of both aerobic and anaerobic metabolisms throughout the time series. This may indicate growth in distinct niches within the gastrointestinal tract. We uncovered differences in the physiology of coexisting Citrobacter strains, including differences in motility and chemotaxis functions. Additionally, for both Citrobacter strains we resolved a community-essential role in vitamin metabolism and a predominant role in propionate production. Finally, in this case study we detected differences between genome abundance and activity levels for the dominant populations. This underlines the value in layering proteomic information over genetic potential.

  11. Methods of lab silos sealing and fermentation characteristics and aerobic stability of sugarcane silage treated with microbial additive

    OpenAIRE

    Charles Ortiz Novinski; Daniel Junges; Patrick Schmidt; Paulo Rossi Junior; João Paulo Gomes de Carvalho; Rodrigo de Almeida Teixeira

    2012-01-01

    The present experimental assay evaluated the effect of lab silo sealing methods on the ensilage of the sugarcane, with or without microbial additives (Lactobacillus plantarum and Propionibacterium acidipropionici). Twenty-liter plastic buckets were used as experimental silos, which were sealed with either a polyethylene sheet (silo cover with a mesh size of 200 µm) or an appropriate plastic lid equipped with Bunsen valve. Silos were stored for 30, 60, or 90 days. Fermentative losses, chemical...

  12. Microbial consortia in Oman oil fields: a possible use in enhanced oil recovery.

    Science.gov (United States)

    Al-Bahry, Saif N; Elshafie, Abdulkader E; Al-Wahaibi, Yahya M; Al-Bemani, Ali S; Joshi, Sanket J; Al-Maaini, Ratiba A; Al-Alawi, Wafa J; Sugai, Yuichi; Al-Mandhari, Mussalam

    2013-01-01

    Microbial enhanced oil recovery (MEOR) is one of the most economical and efficient methods for extending the life of production wells in a declining reservoir. Microbial consortia from Wafra oil wells and Suwaihat production water, Al-Wusta region, Oman were screened. Microbial consortia in brine samples were identified using denaturing gradient gel electrophoresis and 16S rRNA gene sequences. The detected microbial consortia of Wafra oil wells were completely different from microbial consortia of Suwaihat formation water. A total of 33 genera and 58 species were identified in Wafra oil wells and Suwaihat production water. All of the identified microbial genera were first reported in Oman, with Caminicella sporogenes for the first time reported from oil fields. Most of the identified microorganisms were found to be anaerobic, thermophilic, and halophilic, and produced biogases, biosolvants, and biosurfactants as by-products, which may be good candidates for MEOR. PMID:23314376

  13. The effects of fractional wettability on microbial enhanced oil recovery

    Science.gov (United States)

    Wildenschild, D.; Armstrong, R. T.

    2011-12-01

    Microbial enhanced oil recovery (MEOR) is a tertiary oil recovery technology that has had inconsistent success at the field-scale, while lab-scale experiments are mostly successful. One potential reason for these inconsistencies is that the efficacy of MEOR in fractional-wet systems is unknown. Our MEOR strategy consists of the injection of ex situ produced metabolic byproducts produced by Bacillus mojavensis JF-2 (that lower interfacial tension via biosurfactant production) into fractional-wet cores containing residual oil. Fractional-wet cores tested were 50%, 25%, and 0% oil-wet and two different MEOR flooding solutions were tested; one solution contained both microbes and metabolic byproducts while the other contained only the metabolic byproducts. The columns were imaged with x-ray computed microtomography (CMT) after water flooding, and after MEOR, which allowed for the evaluation of the pore-scale processes taking place during MEOR and wettability effects. Results indicate that during MEOR the larger residual oil blobs in mostly fractional-wet pores and residual oil held under relatively low capillary pressures were the main fractions recovered, while residual oil blobs in purely oil-wet pores remained in place. Residual oil saturation, interfacial curvatures, and oil blob sizes were measured from the CMT images and used to develop a conceptual model for MEOR in fractional-wet systems. Overall, results indicate that MEOR was effective at recovering oil from fractional-wet systems with reported additional oil recovered (AOR) values between 44% and 80%; the highest AOR values were observed in the most oil-wet system.

  14. Development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium

    International Nuclear Information System (INIS)

    Microbial assisted phytoremediation is a promising, though yet poorly explored, new remediation technique. The aim of this study was to develop autochthonous microbial consortia resistant to cadmium that could enhance phytoremediation of salt-marsh sediments contaminated with this metal. The microbial consortia were selectively enriched from rhizosediments colonized by Juncus maritimus and Phragmites australis. The obtained consortia presented similar microbial abundance but a fairly different community structure, showing that the microbial community was a function of the sediment from which the consortia were enriched. The effect of the bioaugmentation with the developed consortia on cadmium uptake, and the microbial community structure associated to the different sediments were assessed using a microcosm experiment. Our results showed that the addition of the cadmium resistant microbial consortia increased J. maritimus metal phytostabilization capacity. On the other hand, in P. australis, microbial consortia amendment promoted metal phytoextraction. The addition of the consortia did not alter the bacterial structure present in the sediments at the end of the experiments. This study provides new evidences that the development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium might be a simple, efficient, and environmental friendly remediation procedure. Capsule abstract: Development of autochthonous microbial consortia resistant to cadmium that enhanced phytoremediation by salt-marsh plants, without a long term effect on sediment bacterial diversity. - Highlights: • Cd resistant microbial consortia were developed and applied to salt-marsh sediments. • In Phragmites australis the consortia amendment promoted metal phytoextraction. • The consortia addition increased Juncus maritimus phytostabilization capacity. • No long term changes on the rhizosediment bacterial structure were observed

  15. Development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Catarina [Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Laboratório de Hidrobiologia e Ecologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto (Portugal); Almeida, C. Marisa R.; Nunes da Silva, Marta [Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Bordalo, Adriano A. [Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Laboratório de Hidrobiologia e Ecologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto (Portugal); Mucha, Ana P., E-mail: amucha@ciimar.up.pt [Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal)

    2014-09-15

    Microbial assisted phytoremediation is a promising, though yet poorly explored, new remediation technique. The aim of this study was to develop autochthonous microbial consortia resistant to cadmium that could enhance phytoremediation of salt-marsh sediments contaminated with this metal. The microbial consortia were selectively enriched from rhizosediments colonized by Juncus maritimus and Phragmites australis. The obtained consortia presented similar microbial abundance but a fairly different community structure, showing that the microbial community was a function of the sediment from which the consortia were enriched. The effect of the bioaugmentation with the developed consortia on cadmium uptake, and the microbial community structure associated to the different sediments were assessed using a microcosm experiment. Our results showed that the addition of the cadmium resistant microbial consortia increased J. maritimus metal phytostabilization capacity. On the other hand, in P. australis, microbial consortia amendment promoted metal phytoextraction. The addition of the consortia did not alter the bacterial structure present in the sediments at the end of the experiments. This study provides new evidences that the development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium might be a simple, efficient, and environmental friendly remediation procedure. Capsule abstract: Development of autochthonous microbial consortia resistant to cadmium that enhanced phytoremediation by salt-marsh plants, without a long term effect on sediment bacterial diversity. - Highlights: • Cd resistant microbial consortia were developed and applied to salt-marsh sediments. • In Phragmites australis the consortia amendment promoted metal phytoextraction. • The consortia addition increased Juncus maritimus phytostabilization capacity. • No long term changes on the rhizosediment bacterial structure were observed.

  16. Microsensor Measurements of Sulfate Reduction and Sulfide Oxidation in Compact Microbial Communities of Aerobic Biofilms Rid A-1977-2009

    DEFF Research Database (Denmark)

    KUHL, M.; JØRGENSEN, BB

    1992-01-01

    The microzonation of O2 respiration, H2S oxidation, and SO4(2-) reduction in aerobic trickling-filter biofilms was studied by measuring concentration profiles at high spatial resolution (25 to 100-mu-m) with microsensors for O2, S2-, and pH. Specific reaction rates were calculated from measured......, whereas sulfate reduction occurred in deeper, anoxic parts of the biofilm. Sulfate reduction accounted for up to 50% of the total mineralization of organic carbon in the biofilms. All H2S produced from sulfate reduction was reoxidized by O2 in a narrow reaction zone, and no H2S escaped to the overlying...... water. Turnover times of H2S and O2 in the reaction zone were only a few seconds owing to rapid bacterial H2S oxidation. Anaerobic H2S oxidation with NO3- could be induced by addition of nitrate to the medium. Total sulfate reduction rates increased when the availability of SO4(2-) or organic substrate...

  17. Engineering microbial consortia to enhance biomining and bioremediation

    Directory of Open Access Journals (Sweden)

    Karl Dietrich Brune

    2012-06-01

    Full Text Available In natural environments microorganisms commonly exist as communities of multiple species that are capable of performing more varied and complicated tasks than clonal populations. Synthetic biologists have engineered clonal populations with characteristics such as differentiation, memory and pattern formation, which are usually associated with more complex multicellular organisms. The prospect of designing microbial communities has alluring possibilities for environmental, biomedical and energy applications and is likely to reveal insight into how natural microbial consortia function. Cell signaling and communication pathways between different species are likely to be key processes for designing novel functions in synthetic and natural consortia. Recent efforts to engineer synthetic microbial interactions will be reviewed here, with particular emphasis given to research with significance for industrial applications in the field of biomining and bioremediation of acid mine drainage.

  18. Engineering microbial consortia to enhance biomining and bioremediation.

    Science.gov (United States)

    Brune, Karl D; Bayer, Travis S

    2012-01-01

    In natural environments microorganisms commonly exist as communities of multiple species that are capable of performing more varied and complicated tasks than clonal populations. Synthetic biologists have engineered clonal populations with characteristics such as differentiation, memory, and pattern formation, which are usually associated with more complex multicellular organisms. The prospect of designing microbial communities has alluring possibilities for environmental, biomedical, and energy applications, and is likely to reveal insight into how natural microbial consortia function. Cell signaling and communication pathways between different species are likely to be key processes for designing novel functions in synthetic and natural consortia. Recent efforts to engineer synthetic microbial interactions will be reviewed here, with particular emphasis given to research with significance for industrial applications in the field of biomining and bioremediation of acid mine drainage. PMID:22679443

  19. Nitrate Enhanced Microbial Cr(VI) Reduction-Final Report

    Energy Technology Data Exchange (ETDEWEB)

    John F. Stolz

    2011-06-15

    A major challenge for the bioremediation of radionuclides (i.e., uranium, technetium) and metals (i.e., Cr(VI), Hg) is the co-occurrence of nitrate as it can inhibit metal transformation. Denitrification (nitrate reduction to dinitrogen gas) is considered the most important ecological process. For many metal and metalloid reducing bacteria, however, ammonia is the end product through respiratory nitrate reduction (RNRA). The focus of this work was to determine how RNRA impacts Cr(VI) transformation. The goal was to elucidate the specific mechanism(s) that limits Cr(VI) reduction in the presence of nitrate and to use this information to develop strategies that enhance Cr(VI) reduction (and thus detoxification). Our central hypothesis is that nitrate impacts the biotransformation of metals and metalloids in three ways 1) as a competitive alternative electron acceptor (inhibiting transformation), 2) as a co-metabolite (i.e., concomitant reduction, stimulating transformation), and 3) as an inducer of specific proteins and pathways involved in oxidation/reduction reactions (stimulating transformation). We have identified three model organisms, Geobacter metallireducens (mechanism 1), Sulfurospirillum barnesii, (mechasism 2), and Desulfovibrio desulfuricans (mechanisms 3). Our specific aims were to 1) investigate the role of Cr(VI) concentration on the kinetics of both growth and reduction of nitrate, nitrite, and Cr(VI) in these three organisms; 2) develop a profile of bacterial enzymes involved in nitrate transformation (e.g., oxidoreductases) using a proteomic approach; 3) investigate the function of periplasmic nitrite reductase (Nrf) as a chromate reductase; and 4) develop a strategy to maximize microbial chromium reduction in the presence of nitrate. We found that growth on nitrate by G. metallireducens was inhibited by Cr(VI). Over 240 proteins were identified by LC/MS-MS. Redox active proteins, outer membrane heavy metal efflux proteins, and chemotaxis sensory

  20. Engineering microbial consortia to enhance biomining and bioremediation

    OpenAIRE

    TravisBayer

    2012-01-01

    In natural environments microorganisms commonly exist as communities of multiple species that are capable of performing more varied and complicated tasks than clonal populations. Synthetic biologists have engineered clonal populations with characteristics such as differentiation, memory, and pattern formation, which are usually associated with more complex multicellular organisms. The prospect of designing microbial communities has alluring possibilities for environmental, biomedical, and ene...

  1. Cathode innovations for enhanced H2 production through microbial electrolysis

    NARCIS (Netherlands)

    Jeremiasse, A.W.

    2011-01-01

    Met een microbiële elektrolysecel (MEC) kan waterstof worden gewonnen uit organische reststromen. Aan de bioanode van een MEC zetten elektrochemisch actieve bacteriën organisch materiaal om in stroom, welke vervolgens aan de kathode wordt omgezet in waterstof. Dit proces behoeft een aangelegd voltag

  2. Applications of advanced intervention technologies to enhance microbial food safety

    Science.gov (United States)

    Food safety issues may arise due to chemical and/or microbial contaminations. Foodborne pathogens typically are the major reasons in food related outbreaks that result in human sickness/death, product disposal/waste and other economic losses. The food industry is continuously seeking better interv...

  3. The complicated substrates enhance the microbial diversity and zinc leaching efficiency in sphalerite bioleaching system.

    Science.gov (United States)

    Xiao, Yunhua; Xu, YongDong; Dong, Weiling; Liang, Yili; Fan, Fenliang; Zhang, Xiaoxia; Zhang, Xian; Niu, Jiaojiao; Ma, Liyuan; She, Siyuan; He, Zhili; Liu, Xueduan; Yin, Huaqun

    2015-12-01

    This study used an artificial enrichment microbial consortium to examine the effects of different substrate conditions on microbial diversity, composition, and function (e.g., zinc leaching efficiency) through adding pyrite (SP group), chalcopyrite (SC group), or both (SPC group) in sphalerite bioleaching systems. 16S rRNA gene sequencing analysis showed that microbial community structures and compositions dramatically changed with additions of pyrite or chalcopyrite during the sphalerite bioleaching process. Shannon diversity index showed a significantly increase in the SP (1.460), SC (1.476), and SPC (1.341) groups compared with control (sphalerite group, 0.624) on day 30, meanwhile, zinc leaching efficiencies were enhanced by about 13.4, 2.9, and 13.2%, respectively. Also, additions of pyrite or chalcopyrite could increase electric potential (ORP) and the concentrations of Fe3+ and H+, which were the main factors shaping microbial community structures by Mantel test analysis. Linear regression analysis showed that ORP, Fe3+ concentration, and pH were significantly correlated to zinc leaching efficiency and microbial diversity. In addition, we found that leaching efficiency showed a positive and significant relationship with microbial diversity. In conclusion, our results showed that the complicated substrates could significantly enhance microbial diversity and activity of function. PMID:26266752

  4. Mechanism of enhancement of microbial cell hydrophobicity by cationic polymers.

    OpenAIRE

    Goldberg, S; Doyle, R J; Rosenberg, M

    1990-01-01

    Polycationic polymers have been noted for their effects in promoting cell adhesion to various surfaces, but previous studies have failed to describe a mechanism dealing with this type of adhesion. In the present study, three polycationic polymers (chitosan, poly-L-lysine, and lysozyme) were tested for their effects on microbial hydrophobicity, as determined by adhesion to hydrocarbon and polystyrene. Test strains (Escherichia coli, Candida albicans, and a nonhydrophobic mutant, MR-481, derive...

  5. Microbial characterization before, during and after nitrate-enhanced bioremediation of a jet fuel-contaminated aquifer

    International Nuclear Information System (INIS)

    A JP-4 fuel-contaminated aquifer that underwent a pilot demonstration of nitrate-enhanced bioremediation was characterized microbially before, during and after treatment. The most probable number of total denitrifiers, denitrifiers that use JP-4 or JP-4 degradation products, aerobic and anaerobic protozoa, and the number of heterotrophs and JP-4 degrading microorganisms were determined. The pilot demonstration was conducted by constructing two 100 ft by 100 ft treatment cells, located in a zone of residual contamination, which received either unamended or nitrate-amended recharge water. Core materials were collected in March 1993, August 1994 and May 1995. The demonstration was initiated in April 1994. Preliminary analysis of the results indicates that the number of total denitrifiers in the treatment zone increased after 4 months of treatment but declined to initial levels by the end of the demonstration. However, the number of denitrifiers that use JP-4 or its degradation products, heterotrophs and JP-4 degraders declined after 4 months, and then increased by the final sampling, even in the control samples. Measurements of contaminant concentrations at the interim sampling indicated little removal; however, BTEX concentrations in the ground water at the final sampling were less than initial levels

  6. Profiling of Indigenous Microbial Community Dynamics and Metabolic Activity During Enrichment in Molasses-Supplemented Crude Oil-Brine Mixtures for Improved Understanding of Microbial Enhanced Oil Recovery

    DEFF Research Database (Denmark)

    Halim, Amalia Yunita; Pedersen, Dorthe Skou; Nielsen, Sidsel Marie;

    2015-01-01

    Anaerobic incubations using crude oil and brine from a North Sea reservoir were conducted to gain increased understanding of indigenous microbial community development, metabolite production, and the effects on the oil–brine system after addition of a complex carbon source, molasses....... The microbial growth caused changes in the crude oil–brine system: formation of oil emulsions, and reduction of interfacial tension (IFT). Reduction in IFT was associated with microbes being present at the oil–brine interphase. These findings suggest that stimulation of indigenous microbial growth by addition...... of molasses has potential as microbial enhanced oil recovery (MEOR) strategy in North Sea oil reservoirs....

  7. Quantitative Modeling Of Formation Damage On The Reservoir During Microbial Enhanced Oil Recovery

    Directory of Open Access Journals (Sweden)

    Nmegbu, Chukwuma Godwin Jacob

    2014-07-01

    Full Text Available Microbial enhanced oil recovery is an inexpensive, environmentally friendly method of oil recovery, utilizing the potentials of certain microbes to significantly influence oil productionwith wide range of oil recovery mechanisms including oil mobilization, reservoir re-pressurization, permeability alteration, mobility control and a range of other exploitable recovery techniques. This study presents an investigation on the degree of damage to the reservoir as a result of microbial injection. Results from this analysis shows that for a continuous microbial injection process, the pore area of the formation reduces equivalently due to microbial plugging and or as a result of biomass accumulation in the reservoir. The prevailing effects of formation damage (skin due to these microbes are also presented. Residual fluid flow rates and corresponding velocities were found to reduce in magnitude with deducing pore area after several days of injection.

  8. Microbial Reverse Electrodialysis Cells for Synergistically Enhanced Power Production

    KAUST Repository

    Kim, Younggy

    2011-07-01

    A new type of bioelectrochemical system for producing electrical power, called a microbial reverse-electrodialysis cell (MRC), was developed to increase voltages and power densities compared to those generated individually by microbial fuel cells (MFCs) or reverse electrodialysis (RED) systems. In RED systems, electrode overpotentials create significant energy losses due to thermodynamically unfavorable electrode reactions, and therefore a large number of stacked cells must be used to have significant energy recovery. This results in high capital costs for the large number of membranes, and increases energy losses from pumping water through a large number of cells. In an MRC, high overpotentials are avoided through oxidation of organic matter by exoelectrogenic bacteria on the anode and oxygen reduction on the cathode. An MRC containing only five pairs of RED cells, fed solutions typical of seawater (600 mM NaCl) and river water (12 mM NaCl) at 0.85 mL/min, produced up to 3.6 W/m2 (cathode surface area) and 1.2-1.3 V with acetate as a substrate. Pumping accounted for <2% of the produced power. A higher flow rate (1.55 mL/min) increased power densities up to 4.3 W/m2. COD removal was 98% with a Coulombic efficiency of 64%. Power production by the individual components was substantially lower with 0.7 W/m2 without salinity driven energy, and <0.015 W/m2 with reduced exoelectrogenic activity due to substrate depletion. These results show that the combination of an MFC and a RED stack synergistically increases performance relative to the individual systems, producing a new type of system that can be used to more efficiently capture salinity driven energy from seawater and river water. © 2011 American Chemical Society.

  9. Wiring microbial biofilms to the electrode by osmium redox polymer for the performance enhancement of microbial fuel cells.

    Science.gov (United States)

    Yuan, Yong; Shin, Hyosul; Kang, Chan; Kim, Sunghyun

    2016-04-01

    An osmium redox polymer, PAA-PVI-[Os(4,4'-dimethyl-2,2'-bipyridine)2Cl]+/2+ that has been used in enzymatic fuel cells and microbial sensors, was applied for the first time to the anode of single-chamber microbial fuel cells with the mixed culture inoculum aiming at enhancing performance. Functioning as a molecular wire connecting the biofilm to the anode, power density increased from 1479 mW m(-2) without modification to 2355 mW m(-2) after modification of the anode. Evidence from cyclic voltammetry showed that the catalytic activity of an anodic biofilm was greatly enhanced in the presence of an osmium redox polymer, indicating that electrons were more efficiently transferred to the anode via co-immobilized osmium complex tethered to wiring polymer chains at the potential range of -0.3 V-+0.1 V (vs. SCE). The optimum amount of the redox polymer was determined to be 0.163 mg cm(-2). PMID:26599210

  10. Microbial Enhanced Oil Recovery-Laboratory Experiments with a Strain of Clostridium tyrobutyricum

    DEFF Research Database (Denmark)

    Jimoh, Ismaila Adetunji

    It is well known that each microbial enhanced oil recovery (MEOR) method has its own selection criteria in order to match different reservoir conditions. Therefore successful application of MEOR method depends on the ability of microbes to adapt to extreme reservoir conditions and to produce the...

  11. Microbial degradation of hydrocarbons and its applications to enhanced oil recovery at lab scale

    OpenAIRE

    Pereira, Jorge F. B.; Gudiña, Eduardo J.; L. R. Rodrigues; J.A. Teixeira; Coutinho, J.A.P.

    2011-01-01

    The renewed interest in Enhanced Oil Recovery (EOR) techniques as a consequence of the current oil prices is boosting the development of the Microbial Enhanced Oil Recovery (MEOR). This technique is useful to recover incremental oil from a reservoir beyond primary and secondary recovery operations and can be carried by the injection of exogenous or stimulation of indigenous microorganisms. This last approach is here investigated. In this work we address the isolation and identification of mic...

  12. Isolation and study of microorganisms from oil samples for application in Microbial Enhanced Oil Recovery

    OpenAIRE

    Gudiña, Eduardo J.; Pereira, Jorge F. B.; L. R. Rodrigues; Coutinho, João A. P.; J.A. Teixeira

    2012-01-01

    Microbial Enhanced Oil Recovery (MEOR) is potentially useful to increment oil recovery from a reservoir beyond primary and secondary recovery operations using microorganisms and their metabolites. Stimulation of bacterial growth for biosurfactant production and degradation of heavy oil fractions by indigenous microorganisms can enhance the fluidity and reduce the capillary forces that retain the oil into the reservoir. MEOR offers major advantages over conventional EOR, namely low...

  13. Microbial enhanced oil recovery—a modeling study of the potential of spore-forming bacteria

    DEFF Research Database (Denmark)

    Nielsen, Sidsel Marie; Nesterov, Igor; Shapiro, Alexander

    2016-01-01

    Microbial enhanced oil recovery (MEOR) utilizes microbes for enhancing the recovery by several mechanisms, among which the most studied are the following: (1) reduction of oil-water interfacial tension (IFT) by the produced biosurfactant and (2) selective plugging by microbes and metabolic products...... spore-forming bacteria gives a higher total production of surfactant and the reduced risk of clogging, leading to an increased period of production and a higher oil recovery....

  14. Microbial enhancement of compost extracts based on cattle rumen content compost - characterisation of a system.

    Science.gov (United States)

    Shrestha, Karuna; Shrestha, Pramod; Walsh, Kerry B; Harrower, Keith M; Midmore, David J

    2011-09-01

    Microbially enhanced compost extracts ('compost tea') are being used in commercial agriculture as a source of nutrients and for their perceived benefit to soil microbiology, including plant disease suppression. Rumen content material is a waste of cattle abattoirs, which can be value-added by conversion to compost and 'compost tea'. A system for compost extraction and microbial enhancement was characterised. Molasses amendment increased bacterial count 10-fold, while amendment based on molasses and 'fish and kelp hydrolysate' increased fungal count 10-fold. Compost extract incubated at 1:10 (w/v) dilution showed the highest microbial load, activity and humic/fulvic acid content compared to other dilutions. Aeration increased the extraction efficiency of soluble metabolites, and microbial growth rate, as did extraction of compost without the use of a constraining bag. A protocol of 1:10 dilution and aerated incubation with kelp and molasses amendments is recommended to optimise microbial load and fungal-to-bacterial ratio for this inoculum source. PMID:21752637

  15. Using Microbial Source Tracking to Enhance Environmental Stewardship of Agriculture

    Science.gov (United States)

    Martin, Sherry; Rose, Joan; Flood, Matthew; Aw, Tiong; Hyndman, David

    2016-04-01

    Large scale agriculture relies on the application of chemical fertilizers and animal manure. It is well known that nutrients in excess of a plant's uptake and soil retention capacity can travel to nearby waterways via surface run-off and groundwater pathways, indirectly fertilizing these aquatic ecosystems. It has not yet been possible to distinguish water quality impacts of fertilizer from those derived from human and animal waste sources. However, new microbial source tracking (MST) tools allow specific identification of fecal pollution. Our objective was to examine pollution risks at the regional scale using MST, mapping and classification and regression tree analysis. We present results Bovine M2 genetic marker data from three flow regimes (baseflow, snow melt, and post-planting rain). Key landscape characteristics were related to the presence of the bovine markers and appear to be related to fate and transport. Impacts at this regional watershed scale will be discussed. Our research aims to identify the impacts of agricultural management practices on water quality by linking nutrient concentrations with fecal pollution sources. We hope that our research will provide guidance that will help improve water quality through agricultural best management practices to reduce pathogen contamination.

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

    Science.gov (United States)

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

    2016-03-01

    Sequential anaerobic-aerobic digestion has been demonstrated to be effective for enhanced sludge stabilization, in terms of increased solid reduction and improvement of sludge dewaterability. In this study, we propose a modified version of the sequential anaerobic-aerobic digestion process by operating the aerobic step under mesophilic conditions (T=37 °C), in order to improve the aerobic degradation kinetics of soluble and particulate chemical oxygen demand (COD). Process performance has been assessed in terms of "classical parameters" such as volatile solids (VS) removal, biogas production, COD removal, nitrogen species, and polysaccharide and protein fate. The aerobic step was operated under intermittent aeration to achieve nitrogen removal. Aerobic mesophilic conditions consistently increased VS removal, providing 32% additional removal vs. 20% at 20 °C. Similar results were obtained for nitrogen removal, increasing from 64% up to 99% at the higher temperature. Improved sludge dewaterability was also observed with a capillary suction time decrease of ~50% during the mesophilic aerobic step. This finding may be attributable to the decreased protein content in the aerobic digested sludge. The post-aerobic digestion exerted a positive effect on the reduction of microbial indicators while no consistent improvement of hygienization related to the increased temperature was observed. The techno-economic analysis of the proposed digestion layout showed a net cost saving for sludge disposal estimated in the range of 28-35% in comparison to the single-phase anaerobic digestion. PMID:26760266

  17. Medium factors on anaerobic production of rhamnolipids by Pseudomonas aeruginosa SG and a simplifying medium for in situ microbial enhanced oil recovery applications.

    Science.gov (United States)

    Zhao, Feng; Zhou, Jidong; Han, Siqin; Ma, Fang; Zhang, Ying; Zhang, Jie

    2016-04-01

    Aerobic production of rhamnolipid by Pseudomonas aeruginosa was extensively studied. But effect of medium composition on anaerobic production of rhamnolipid by P. aeruginosa was unknown. A simplifying medium facilitating anaerobic production of rhamnolipid is urgently needed for in situ microbial enhanced oil recovery (MEOR). Medium factors affecting anaerobic production of rhamnolipid were investigated using P. aeruginosa SG (Genbank accession number KJ995745). Medium composition for anaerobic production of rhamnolipid by P. aeruginosa is different from that for aerobic production of rhamnolipid. Both hydrophobic substrate and organic nitrogen inhibited rhamnolipid production under anaerobic conditions. Glycerol and nitrate were the best carbon and nitrogen source. The commonly used N limitation under aerobic conditions was not conducive to rhamnolipid production under anaerobic conditions because the initial cell growth demanded enough nitrate for anaerobic respiration. But rhamnolipid was also fast accumulated under nitrogen starvation conditions. Sufficient phosphate was needed for anaerobic production of rhamnolipid. SO4(2-) and Mg(2+) are required for anaerobic production of rhamnolipid. Results will contribute to isolation bacteria strains which can anaerobically produce rhamnolipid and medium optimization for anaerobic production of rhamnolipid. Based on medium optimization by response surface methodology and ions composition of reservoir formation water, a simplifying medium containing 70.3 g/l glycerol, 5.25 g/l NaNO3, 5.49 g/l KH2PO4, 6.9 g/l K2HPO4·3H2O and 0.40 g/l MgSO4 was designed. Using the simplifying medium, 630 mg/l of rhamnolipid was produced by SG, and the anaerobic culture emulsified crude oil to EI24 = 82.5 %. The simplifying medium was promising for in situ MEOR applications. PMID:26925616

  18. Profiling of Indigenous Microbial Community Dynamics and Metabolic Activity During Enrichment in Molasses-Supplemented Crude Oil-Brine Mixtures for Improved Understanding of Microbial Enhanced Oil Recovery.

    Science.gov (United States)

    Halim, Amalia Yunita; Pedersen, Dorthe Skou; Nielsen, Sidsel Marie; Lantz, Anna Eliasson

    2015-06-01

    Anaerobic incubations using crude oil and brine from a North Sea reservoir were conducted to gain increased understanding of indigenous microbial community development, metabolite production, and the effects on the oil-brine system after addition of a complex carbon source, molasses, with or without nitrate to boost microbial growth. Growth of the indigenous microbes was stimulated by addition of molasses. Pyrosequencing showed that specifically Anaerobaculum, Petrotoga, and Methanothermococcus were enriched. Addition of nitrate favored the growth of Petrotoga over Anaerobaculum. The microbial growth caused changes in the crude oil-brine system: formation of oil emulsions, and reduction of interfacial tension (IFT). Reduction in IFT was associated with microbes being present at the oil-brine interphase. These findings suggest that stimulation of indigenous microbial growth by addition of molasses has potential as microbial enhanced oil recovery (MEOR) strategy in North Sea oil reservoirs. PMID:25894951

  19. Enhanced Microbial Pathways for Methane Production from Oil Shale

    Energy Technology Data Exchange (ETDEWEB)

    Paul Fallgren

    2009-02-15

    Methane from oil shale can potentially provide a significant contribution to natural gas industry, and it may be possible to increase and continue methane production by artificially enhancing methanogenic activity through the addition of various substrate and nutrient treatments. Western Research Institute in conjunction with Pick & Shovel Inc. and the U.S. Department of Energy conducted microcosm and scaled-up reactor studies to investigate the feasibility and optimization of biogenic methane production from oil shale. The microcosm study involving crushed oil shale showed the highest yield of methane was produced from oil shale pretreated with a basic solution and treated with nutrients. Incubation at 30 C, which is the estimated temperature in the subsurface where the oil shale originated, caused and increase in methane production. The methane production eventually decreased when pH of the system was above 9.00. In the scaled-up reactor study, pretreatment of the oil shale with a basic solution, nutrient enhancements, incubation at 30 C, and maintaining pH at circumneutral levels yielded the highest rate of biogenic methane production. From this study, the annual biogenic methane production rate was determined to be as high as 6042 cu. ft/ton oil shale.

  20. Modelling and laboratory investigation of microbial enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Desouky, S.M. [King Saud University, College of Engineering, Riyadh (Saudi Arabia); Abdel-Daim, M.M.; Sayyouh, M.H.; Dahab, A.S. [Cairo University, College of Engineering and Petroleum Engineering Department, Giza (Egypt)

    1996-08-15

    A one-dimensional model was developed to simulate the process of enhanced oil recovery by microorganisms. The model involves five components (oil, water, bacteria, nutrient and metabolites), with adsorption, diffusion, chemotaxis, growth and decay of bacteria, nutrient consumption, permeability damage and porosity reduction effects. Experiments were conducted to identify the parameters affecting the transport and growth of three bacterial strains: Streptococcus, Staphylococcus and Bacillus in porous media. Several correlations were developed from the experimental laboratory data and were used in the simulator. Comparison between the experimental and simulated results emphasized the validity of the developed simulator and determined its degree of accuracy (average absolute relative error=8.323%). The simulator was used to investigate the effects of indigenous bacteria, slug size, incubation time, residual oil saturation, absolute permeability, and injection flow rate on oil recovery. Results show that more oil can be recovered by using Streptococcus with molasses as a medium. Oil recovery is sensitive to variation in concentration of injected indigenous bacteria, size of bacterial culture slug, incubation time and residual oil saturation. The change of absolute permeability, or injection flow rate, has no effect on oil recovery efficiency by bacteria

  1. Novel bioemulsifier produced by a Paenibacilus sp. strain and its applicability in microbial enhanced oil recovery

    OpenAIRE

    Gudiña, Eduardo J.; L. R. Rodrigues; J.A. Teixeira

    2015-01-01

    Microbial Enhanced Oil Recovery (MEOR) is potentially useful to increment oil recovery from reservoirs beyond primary and secondary recovery operations using microorganisms and their metabolites. In situ stimulation of microorganisms that produce surface active compounds reduces the capillary forces that retain the oil inside the reservoir, thus promoting its flow and increasing oil production. Paenibacillus sp. #510, isolated from crude oil samples obtained from a Brazilian oil field, produc...

  2. Microbial enhanced oil recovery by Bacillus subtilis strains under simulated reservoir conditions

    OpenAIRE

    Gudiña, Eduardo J.; L. R. Rodrigues; J.A. Teixeira; Pereira, J. F.; Coutinho, J.A.P.; Soares, L. P.; Ribeiro, M. T.

    2012-01-01

    Microbial Enhanced Oil Recovery (MEOR) is a tertiary oil recovery process in which microorganisms and their metabolites are used to retrieve unrecoverable oil from mature reservoirs. Stimulation of microorganisms that produce biosurfactants and degrade heavy oil fractions in situ reduces the capillary forces that retain the oil into the reservoir and decreases oil viscosity, thus promoting its flow. As a result, oil production can be increased. In previous work, Bacillus subtilis strains that...

  3. Numerical Modelling of Microbial Enhanced Oil Recovery with Focus on Dynamic Effects: An Iterative Approach

    OpenAIRE

    Skiftestad, Kai

    2015-01-01

    Recovering more of the available oil has been a main driver behind the extensive work done in the field of enhanced oil recovery (EOR) over the last decades. Microbial en- hanced oil recovery (MEOR) has been heavily researched, and is picking up pace com- pared with other EOR methods used today. MEOR is economically attractive and has a huge potential if applied in accordance to reservoir conditions. This thesis considers a two-phase flow regime in homogeneous porous media, under the influenc...

  4. Graphene-modified Electrodes for Enhancing the Performance of Microbial Fuel Cells

    OpenAIRE

    Yuan, Heyang; He, Zhen

    2014-01-01

    Graphene is an emerging material with superior physical and chemical properties, which can benefit the development of microbial fuel cells (MFC) in several aspects. Graphene-based anodes can enhance MFC performance with increased electron transfer efficiency, higher specific surface area and more active microbe-electrode-electrolyte interaction. For cathodic processes, oxygen reduction reaction is effectively catalyzed by graphene-based materials because of a favorable pathway and an increase...

  5. Biogenic palladium enhances diatrizoate removal from hospital wastewater in a microbial electrolysis cell

    OpenAIRE

    De Gusseme, Bart; Hennebel, Tom; Vanhaecke, Lynn; Soetaert, Maarten; Desloover, Joachim; Wille, Klaas; Verbeken, Kim; Verstraete, Willy; Boon, Nico

    2011-01-01

    decrease the load of pharmaceuticals to the environment, decentralized wastewater treatment has been proposed for important point-sources such as hospitals. In this study, a microbial electrolysis cell (MEC) was used for the dehalogenation of the iodinated X-ray contrast medium diatrizoate. The presence of biogenic palladium nanoparticles (bio-Pd) in the cathode significantly enhanced diatrizoate removal by direct electrochemical reduction and by reductive catalysis using the H(2) gas produce...

  6. Microbially enhanced carbon capture and storage - from pores to cores (Invited)

    Science.gov (United States)

    Mitchell, A. C.; Cunningham, A. B.; Spangler, L.; Gerlach, R.

    2010-12-01

    During the operation of Geologic Carbon Capture and Storage (CCS) and the injection of supercritical CO2 into underground formations, microbe-rock-fluid interactions occur. These interactions may be important for controlling the ultimate fate of the injected CO2, and may also be manipulated to enhance the storage of the CO2, via mineral-trapping, solubility trapping, formation trapping, and leakage reduction. We have demonstrated that engineered microbial biofilms are capable of enhancing formation, mineral, and solubility trapping in carbon sequestration-relevant formation materials. Batch and flow experiments at atmospheric and high pressures (> 74 bar) have shown the ability of microbial biofilms to decrease the permeability of natural and artificial porous media, survive the exposure to supercritical CO2, and facilitate the conversion of gaseous and supercritical CO2 into long-term stable carbonate phases as well as increase the solubility of CO2 in brines. Ongoing microscopy and modelling studies aim to understand these processes at both the pore- and core-scale in order to facilitate larger scale understanding and potential manipulation for biologically based CCS engineering. Successful development of these biologically-based concepts could result in microbially enhanced carbon sequestration strategies as well as CO2 leakage mitigation technologies, which can be applied either before CO2 injection or as a remedial measure around injection wells.

  7. Characterization of indigenous oil field microorganisms for microbially enhanced oil recovery (MEOR)

    Energy Technology Data Exchange (ETDEWEB)

    Sitte, J.; Krueger, M. [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany); Biegel, E.; Herold, A. [BASF SE, Ludwigshafen (Germany); Alkan, H. [Wintershall Holding GmbH, Kassel (Germany)

    2013-08-01

    Microbial activities and their resulting metabolites became a focus of attention for enhanced oil recovery (MEOR, microbial enhanced oil recovery) in the recent years. In order to develop a strategy for a MEOR application in a German oil field operated by Wintershall experiments were performed to investigate different sampling strategies and the microbial communities found in these samples. The objectives of this study were (1) to characterize the indigenous microbial communities, (2) to investigate the dependency of microbial activity/diversity on the different sampling strategies, and (3) to study the influence of the in situ pressure on bacterial growth and metabolite production. Fluids were sampled at the well head (surface) and in situ in approx. 785 m depth to collect uncontaminated production water directly from the reservoir horizon and under the in situ pressure of 31 bar (subsurface). In the lab the pressure was either released quickly or slowly to assess the sensitivity of microorganisms to rapid pressure changes. Quantitative PCR resulted in higher microbial cell numbers in the subsurface than in the surface sample. Biogenic CO{sub 2} and CH{sub 4} formation rates were determined under atmospheric and high pressure conditions in the original fluids, with highest rates found in the surface fluid. Interestingly, no methane was formed in the native fluid samples. While nitrate reduction was exclusively detected in the surface samples, sulfide formation also occurred in the subsurface fluids. Increased CO{sub 2} formation was measured after addition of a variety of substrates in the surface fluids, while only fructose and glucose showed a stimulating effect on CO{sub 2} production for the subsurface sample. Stable enrichment cultures were obtained in complex medium inoculated with the subsurface fluid, both under atmospheric and in situ pressure. Growth experiments with constant or changing pressure, and subsequent DGGE analysis of bacterial 16S rRNA genes

  8. Performances and microbial features of an aerobic packed-bed biofilm reactor developed to post-treat an olive mill effluent from an anaerobic GAC reactor

    Directory of Open Access Journals (Sweden)

    Marchetti Leonardo

    2006-04-01

    Full Text Available Abstract Background Olive mill wastewater (OMW is the aqueous effluent of olive oil producing processes. Given its high COD and content of phenols, it has to be decontaminated before being discharged. Anaerobic digestion is one of the most promising treatment process for such an effluent, as it combines high decontamination efficiency with methane production. The large scale anaerobic digestion of OMWs is normally conducted in dispersed-growth reactors, where however are generally achieved unsatisfactory COD removal and methane production yields. The possibility of intensifying the performance of the process using a packed bed biofilm reactor, as anaerobic treatment alternative, was demonstrated. Even in this case, however, a post-treatment step is required to further reduce the COD. In this work, a biological post-treatment, consisting of an aerobic biological "Manville" silica bead-packed bed aerobic reactor, was developed, tested for its ability to complete COD removal from the anaerobic digestion effluents, and characterized biologically through molecular tools. Results The aerobic post-treatment was assessed through a 2 month-continuous feeding with the digested effluent at 50.42 and 2.04 gl-1day-1 of COD and phenol loading rates, respectively. It was found to be a stable process, able to remove 24 and 39% of such organic loads, respectively, and to account for 1/4 of the overall decontamination efficiency displayed by the anaerobic-aerobic integrated system when fed with an amended OMW at 31.74 and 1.70 gl-1day-1 of COD and phenol loading rates, respectively. Analysis of 16S rRNA gene sequences of biomass samples from the aerobic reactor biofilm revealed that it was colonized by Rhodobacterales, Bacteroidales, Pseudomonadales, Enterobacteriales, Rhodocyclales and genera incertae sedis TM7. Some taxons occurring in the influent were not detected in the biofilm, whereas others, such as Paracoccus, Pseudomonas, Acinetobacter and Enterobacter

  9. Similar enhancement of BK(Ca) channel function despite different aerobic exercise frequency in aging cerebrovascular myocytes.

    Science.gov (United States)

    Li, N; Liu, B; Xiang, S; Shi, L

    2016-07-18

    Aerobic exercise showed beneficial influence on cardiovascular systems in aging, and mechanisms underlying vascular adaption remain unclear. Large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels play critical roles in regulating cellular excitability and vascular tone. This study determined the effects of aerobic exercise on aging-associated functional changes in BK(Ca) channels in cerebrovascular myocytes, Male Wistar rats aged 20-22 months were randomly assigned to sedentary (O-SED), low training frequency (O-EXL), and high training frequency group (O-EXH). Young rats were used as control. Compared to young rats, whole-cell BK(Ca) current was decreased, and amplitude of spontaneous transient outward currents were reduced. The open probability and Ca(2+)/voltage sensitivity of single BK(Ca) channel were declined in O-SED, accompanied with a reduction of tamoxifen-induced BK(Ca) activation; the mean open time of BK(Ca) channels was shortened whereas close time was prolonged. Aerobic exercise training markedly alleviated the aging-associated decline independent of training frequency. Exercise three times rather than five times weekly may be a time and cost-saving training volume required to offer beneficial effects to offset the functional declines of BK(Ca) during aging. PMID:27070745

  10. Enhanced Biological Phosphorus Removal in Anaerobic/Aerobic Sequencing Batch Reactor Supplied with Glucose as Carbon Source

    Institute of Scientific and Technical Information of China (English)

    LIU Yanan; YU Shui-li; JING Guo-lin; ZHAO Bing-jie; GUO Si-yuan

    2005-01-01

    Phosphorus removal performance in an aerobic/aerobic sequencing batch reactor (SBR) supplied with glucose as carbon source was investigated. It was found that there was no phosphate release concomitant with the storing of poly-β-hydroxyalkanoate (PHA) during the anaerobic phase. Whereas, glycogen was soon built up followed by rapid consumption, at the same time, glucose was depleted rapidly. Based on the analysis of different fractions of phosphorus in activated sludge, the relative ratio of organically bound phosphorus in sludge changed at the end of anaerobic and aerobic phases. The ratios were 45.3% and51.8% respectively. This showed that the polyphosphate broke down during the anaerobic phase to supply part of energy for PHA synthesis. The reason why there was no phosphate release might be the biosorption effect of extracellular exopolymers (EPS). It was also proved by the analysis of EPS with scanning electron microscopy (SEM)combined with energy dispersive spectrometry (EDS). The phosphorus weight percentage of EPS at the end of anaerobic phase was 9.22%.

  11. Applicability of anaerobic nitrate-dependent Fe(II) oxidation to microbial enhanced oil recovery (MEOR).

    Science.gov (United States)

    Zhu, Hongbo; Carlson, Han K; Coates, John D

    2013-08-01

    Microbial processes that produce solid-phase minerals could be judiciously applied to modify rock porosity with subsequent alteration and improvement of floodwater sweep in petroleum reservoirs. However, there has been little investigation of the application of this to enhanced oil recovery (EOR). Here, we investigate a unique approach of altering reservoir petrology through the biogenesis of authigenic rock minerals. This process is mediated by anaerobic chemolithotrophic nitrate-dependent Fe(II)-oxidizing microorganisms that precipitate iron minerals from the metabolism of soluble ferrous iron (Fe(2+)) coupled to the reduction of nitrate. This mineral biogenesis can result in pore restriction and reduced pore throat diameter. Advantageously and unlike biomass plugs, these biominerals are not susceptible to pressure or thermal degradation. Furthermore, they do not require continual substrate addition for maintenance. Our studies demonstrate that the biogenesis of insoluble iron minerals in packed-bed columns results in effective hydrology alteration and homogenization of heterogeneous flowpaths upon stimulated microbial Fe(2+) biooxidation. We also demonstrate almost 100% improvement in oil recovery from hydrocarbon-saturated packed-bed columns as a result of this metabolism. These studies represent a novel departure from traditional microbial EOR approaches and indicate the potential for nitrate-dependent Fe(2+) biooxidation to improve volumetric sweep efficiency and enhance both the quality and quantity of oil recovered. PMID:23799785

  12. Exopolysaccharide production by a genetically engineered Enterobacter cloacae strain for microbial enhanced oil recovery.

    Science.gov (United States)

    Sun, Shanshan; Zhang, Zhongzhi; Luo, Yijing; Zhong, Weizhang; Xiao, Meng; Yi, Wenjing; Yu, Li; Fu, Pengcheng

    2011-05-01

    Microbial enhanced oil recovery (MEOR) is a petroleum biotechnology for manipulating function and/or structure of microbial environments existing in oil reservoirs for prolonged exploitation of the largest source of energy. In this study, an Enterobacter cloacae which is capable of producing water-insoluble biopolymers at 37°C and a thermophilic Geobacillus strain were used to construct an engineered strain for exopolysaccharide production at higher temperature. The resultant transformants, GW3-3.0, could produce exopolysaccharide up to 8.83 g l(-1) in molasses medium at 54°C. This elevated temperature was within the same temperature range as that for many oil reservoirs. The transformants had stable genetic phenotype which was genetically fingerprinted by RAPD analysis. Core flooding experiments were carried out to ensure effective controlled profile for the simulation of oil recovery. The results have demonstrated that this approach has a promising application potential in MEOR. PMID:21444201

  13. Enhanced methane production via repeated batch bioaugmentation pattern of enriched microbial consortia.

    Science.gov (United States)

    Yang, Zhiman; Guo, Rongbo; Xu, Xiaohui; Wang, Lin; Dai, Meng

    2016-09-01

    Using batch and repeated batch cultivations, this study investigated the effects of bioaugmentation with enriched microbial consortia (named as EMC) on methane production from effluents of hydrogen-producing stage of potato slurry, as well as on the indigenous bacterial community. The results demonstrated that the improved methane production and shift of the indigenous bacterial community structure were dependent on the EMC/sludge ratio and bioaugmentation patterns. The methane yield and production rate in repeated batch bioaugmentation pattern of EMC were, respectively, average 15% and 10% higher than in one-time bioaugmentation pattern of EMC. DNA-sequencing approach showed that the enhanced methane production in the repeated batch bioaugmentation pattern of EMC mainly resulted from the enriched iron-reducing bacteria and the persistence of the introduced Syntrophomonas, which led to a rapid degradation of individual VFAs to methane. The findings contributed to understanding the correlation between the bioaugmentation of microbial consortia, community shift, and methane production. PMID:27262722

  14. Enhancing anaerobic digestion of cotton stalk by pretreatment with a microbial consortium (MC1).

    Science.gov (United States)

    Yuan, Xufeng; Ma, Lei; Wen, Boting; Zhou, Dayun; Kuang, Meng; Yang, Weihua; Cui, Zongjun

    2016-05-01

    Microbial pretreatment is beneficial in some anaerobic digestion systems, but the consortia used to date have not been able to effectively increase methane production from cotton stalk. In this study, a thermophilic microbial consortium (MC1) was used for pretreatment in order to enhance biogas and methane production yields. The results indicated that the concentrations of soluble chemical oxygen demand and volatile organic products increased significantly in the early stages of pretreatment. Ethanol, acetic acid, propionic acid, and butyric acid were the predominant volatile organic products in the MC1 hydrolysate. Biogas and methane production yields from cotton stalk were significantly increased following MC1 pretreatment. In addition, the methane production rate from the treated cotton stalk was greater than that from the untreated sample. PMID:26896713

  15. Power generation enhancement in novel microbial carbon capture cells with immobilized Chlorella vulgaris

    Science.gov (United States)

    Zhou, Minghua; He, Huanhuan; Jin, Tao; Wang, Hongyu

    2012-09-01

    With the increasing concerns for global climate change, a sustainable, efficient and renewable energy production from wastewater is imperative. In this study, a novel microbial carbon capture cell (MCC), is constructed for the first time by the introduction of immobilized microalgae (Chlorella vulgaris) into the cathode chamber of microbial fuel cells (MFCs) to fulfill the zero discharge of carbon dioxide. This process can achieve an 84.8% COD removal, and simultaneously the maximum power density can reach 2485.35 mW m-3 at a current density of 7.9 A m-3 and the Coulombic efficiency is 9.40%, which are 88% and 57.7% greater than that with suspended C. vulgaris, respectively. These enhancements in performance demonstrate the feasibility of an economical and effective approach for the simultaneous wastewater treatment, electricity generation and biodiesel production from microalgae.

  16. Impact of an indigenous microbial enhanced oil recovery field trial on microbial community structure in a high pour-point oil reservoir.

    Science.gov (United States)

    Zhang, Fan; She, Yue-Hui; Li, Hua-Min; Zhang, Xiao-Tao; Shu, Fu-Chang; Wang, Zheng-Liang; Yu, Long-Jiang; Hou, Du-Jie

    2012-08-01

    Based on preliminary investigation of microbial populations in a high pour-point oil reservoir, an indigenous microbial enhanced oil recovery (MEOR) field trial was carried out. The purpose of the study is to reveal the impact of the indigenous MEOR process on microbial community structure in the oil reservoir using 16Sr DNA clone library technique. The detailed monitoring results showed significant response of microbial communities during the field trial and large discrepancies of stimulated microorganisms in the laboratory and in the natural oil reservoir. More specifically, after nutrients injection, the original dominant populations of Petrobacter and Alishewanella in the production wells almost disappeared. The expected desirable population of Pseudomonas aeruginosa, determined by enrichment experiments in laboratory, was stimulated successfully in two wells of the five monitored wells. Unexpectedly, another potential population of Pseudomonas pseudoalcaligenes which were not detected in the enrichment culture in laboratory was stimulated in the other three monitored production wells. In this study, monitoring of microbial community displayed a comprehensive alteration of microbial populations during the field trial to remedy the deficiency of culture-dependent monitoring methods. The results would help to develop and apply more MEOR processes. PMID:22159733

  17. Impact of an indigenous microbial enhanced oil recovery field trial on microbial community structure in a high pour-point oil reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fan; Zhang, Xiao-Tao; Hou, Du-Jie [China Univ. of Geosciences, Beijing (China). The Key Lab. of Marine Reservoir Evolution and Hydrocarbon Accumulation Mechanism; She, Yue-Hui [Yangtze Univ., Jingzhou, Hubei (China). College of Chemistry and Environmental Engineering; Huazhong Univ. of Science and Technology, Wuhan (China). College of Life Science and Technology; Li, Hua-Min [Beijing Bioscience Research Center (China); Shu, Fu-Chang; Wang, Zheng-Liang [Yangtze Univ., Jingzhou, Hubei (China). College of Chemistry and Environmental Engineering; Yu, Long-Jiang [Huazhong Univ. of Science and Technology, Wuhan (China). College of Life Science and Technology

    2012-08-15

    Based on preliminary investigation of microbial populations in a high pour-point oil reservoir, an indigenous microbial enhanced oil recovery (MEOR) field trial was carried out. The purpose of the study is to reveal the impact of the indigenous MEOR process on microbial community structure in the oil reservoir using 16Sr DNA clone library technique. The detailed monitoring results showed significant response of microbial communities during the field trial and large discrepancies of stimulated microorganisms in the laboratory and in the natural oil reservoir. More specifically, after nutrients injection, the original dominant populations of Petrobacter and Alishewanella in the production wells almost disappeared. The expected desirable population of Pseudomonas aeruginosa, determined by enrichment experiments in laboratory, was stimulated successfully in two wells of the five monitored wells. Unexpectedly, another potential population of Pseudomonas pseudoalcaligenes which were not detected in the enrichment culture in laboratory was stimulated in the other three monitored production wells. In this study, monitoring of microbial community displayed a comprehensive alteration of microbial populations during the field trial to remedy the deficiency of culture-dependent monitoring methods. The results would help to develop and apply more MEOR processes. (orig.)

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  20. A two-year program of aerobics and weight training enhances bone mineral density of young women

    Science.gov (United States)

    Friedlander, A. L.; Genant, H. K.; Sadowsky, S.; Byl, N. N.; Gluer, C. C.

    1995-01-01

    Previous research suggests that physical activity may have a beneficial effect on bone mineral density (BMD) in women. This relationship was explored in a 2-year, randomized, intervention trial investigating the efficacy of exercise and calcium supplementation on increasing peak bone mass in young women. One hundred and twenty-seven subjects (ages of 20-35 years) were randomly assigned either to an exercise program that contained both aerobics and weight training components or to a stretching program. Calcium supplementation (up to 1500 mg/day including dietary intake) or placebo was given in a double-blinded design to all subjects. Spinal trabecular BMD was determined using quantitative computed tomography (QCT). Spinal integral, femoral neck, and trochanteric BMD were measured by dual X-ray absorptiometry (DXA) and calcaneal BMD by single photon absorptiometry (SPA). Fitness variables included maximal aerobic capacity (VO2max), and isokinetic muscle performance of the trunk and thigh. Measurements were made at baseline, 1 year, and 2 years. Sixty-three subjects (32 exercise, 31 stretching) completed the study, and all the measured bone parameters indicated a positive influence of the exercise intervention. There were significant positive differences in BMD between the exercise and stretching groups for spinal trabecular (2.5%), femoral neck (2.4%), femoral trochanteric (2.3%), and calcaneal (6.4%) measurements. The exercise group demonstrated a significant gain in BMD for spinal integral (1.3 +/- 2.8%, p effect on any of the bone parameters. In regard to fitness parameters, the exercise group completed the study with significant gains in VO2max and isokinetic (peak torque) values for the knee flexion and extension and trunk extension. This study indicates that over a 2-year period, a combined regimen of aerobics and weight training has beneficial effects on BMD and fitness parameters in young women. However, the addition of daily calcium supplementation does not

  1. Post-treatment of anaerobically degraded azo dye Acid Red 18 using aerobic moving bed biofilm process: Enhanced removal of aromatic amines

    International Nuclear Information System (INIS)

    Highlights: → Biofilm process was applied as post-treatment of anaerobically degraded an azo dye. → More than 65% of the dye total metabolites was completely mineralized. → Based on HPLC analysis, more than 80% of 1-naphthylamine-4-sulfonate was removed. → Inhibition of biofilm growth was increased with increasing the initial dye concentration. → Considerable porous morphology was observed in the SEM photographs of the biofilm. - Abstract: The application of aerobic moving bed biofilm process as post-treatment of anaerobically degraded azo dye Acid Red 18 was investigated in this study. The main objective of this work was to enhance removal of anaerobically formed the dye aromatic metabolites. Three separate sequential treatment systems were operated with different initial dye concentrations of 100, 500 and 1000 mg/L. Each treatment system consisted of an anaerobic sequencing batch reactor (An-SBR) followed by an aerobic moving bed sequencing batch biofilm reactor (MB-SBBR). Up to 98% of the dye decolorization and more than 80% of the COD removal occurred anaerobically. The obtained results suggested no significant difference in COD removal as well as the dye decolorization efficiency using three An-SBRs receiving different initial dye concentrations. Monitoring the dye metabolites through HPLC suggested that more than 80% of anaerobically formed 1-naphthylamine-4-sulfonate was completely removed in the aerobic biofilm reactors. Based on COD analysis results, at least 65-72% of the dye total metabolites were mineralized during the applied treatment systems. According to the measured biofilm mass and also based on respiration-inhibition test results, increasing the initial dye concentration inhibited the growth and final mass of the attached-growth biofilm in MB-SBBRs.

  2. Bacterial biosurfactants, and their role in microbial enhanced oil recovery (MEOR).

    Science.gov (United States)

    Khire, J M

    2010-01-01

    Surfactants are chemically synthesized surface-active compounds widely used for large number of applications in various industries. During last few years there is increase demand of biological surface-active compounds or biosurfactants which are produced by large number of microorganisms as they exert biodegradability, low toxicity and widespread application compared to chemical surfactants. They can be used as emulsifiers, de-emulsifiers, wetting agents, spreading agents, foaming agents, functional food ingredients and detergents. Various experiments at laboratory scale on sand-pack columns and field trials have successfully indicated effectiveness of biosurfactants in microbial enhanced oil recovery (MEOR). PMID:20545280

  3. Prospects of Microbial Enhanced Oil Recovery  in Danish chalk rocks

    DEFF Research Database (Denmark)

    Rudyk, Svetlana Nikolayevna; Jørgensen, Leif Wagner; Bah Awasi, Ismail

      Microbial Enhanced Oil Recovery (MEOR) uses bacteria, producing gas (CO2), polymers or surfactants to help recover residual oil after the water injection depletes its possibilities. Two strains of Clostridia tyrobutiricum were investigated as possible candidates for MEOR  implementation in Danish...... chalk reservoir rocks. Parameters such as high salinity, low permeability, high temperature and toxic elements, being typical characteristics of Danish fields can cause limiting effects on MEOR applications. The work fulfilled showed that microbes can be adapted to higher salinities through a serial...

  4. Organic amendments enhance microbial diversity and abundance of functional genes in Australian Soils

    Science.gov (United States)

    Aldorri, Sind; McMillan, Mary; Pereg, Lily

    2016-04-01

    Food and cash crops play important roles in Australia's economy with black, grey and red clay soil, widely use for growing cotton, wheat, corn and other crops in rotation. While the majority of cotton growers use nitrogen and phosphate fertilizers only in the form of agrochemicals, a few experiment with the addition of manure or composted plant material before planting. We hypothesized that the use of such organic amendments would enhance the soil microbial function through increased microbial diversity and abundance, thus contribute to improved soil sustainability. To test the hypothesis we collected soil samples from two cotton-growing farms in close geographical proximity and with mostly similar production practices other than one grower has been using composted plants as organic amendment and the second farmer uses only agrochemicals. We applied the Biolog Ecoplate system to study the metabolic signature of microbial communities and used qPCR to estimate the abundance of functional genes in the soil. The soil treated with organic amendments clearly showed higher metabolic activity of a more diverse range of carbon sources as well as higher abundance of genes involved in the nitrogen and phosphorous cycles. Since microbes undertake a large number of soil functions, the use of organic amendments can contribute to the sustainability of agricultural soils.

  5. Microbial Enhanced Oil Recovery and Wettability Research Program. Annual report, FY 1991

    Energy Technology Data Exchange (ETDEWEB)

    Bala, G.A.; Barrett, K.B.; Eastman, S.L.; Herd, M.D.; Jackson, J.D.; Robertson, E.P.; Thomas, C.P.

    1993-09-01

    This report covers research results for fiscal year 1991 for the Microbial Enhanced Oil Recovery (MEOR) and Wettability Research Program conducted by EG&G Idaho, Inc. at the Idaho National Engineering Laboratory ONEL) for the US Department of Energy Idaho Field Office (DOE-ID). The program is funded by the Assistant Secretary of Fossil Energy, and managed by DOE-ID and the Bartlesville Project Office (BPO). The objectives of this multi-year program are to develop MEOR systems for application to reservoirs containing medium to heavy crude oils and to design and implement an industry cost-shared field demonstration project of the developed technology. An understanding of the controlling mechanisms will first be developed through the use of laboratory scale testing to determine the ability of microbially mediated processes to recover oil under reservoir conditions and to develop the design criteria for scale-up to the field. Concurrently with this work, the isolation and characterization of microbial species collected from various locations including target oil field environments is underway to develop more effective oil recovery systems for specific applications. Research focus includes the study of biogenic product and formation souring processes including mitigation and prevention. Souring research performed in FY 1991 also included the development of microsensor probe technology for the detection of total sulfide in collaboration with the Montana State University Center for Interfacial Microbial Process Engineering (CIMPE). Wettability research is a multi-year collaborative effort with the New Mexico Petroleum Recovery Research Center (NMPRRC) at the New Mexico institute of Mining and Technology, Socorro, NM to evaluate reservoir wettability and its effects on oil recovery. Results from the wettability research will be applied to determine if alteration of wettability is a significant contributing mechanism for MEOR systems.

  6. DETECTION OF A MICROBIAL CONSORTIUM, INCLUDING TYPE 2 METHANOTROPHS, BY USE OF PHOSPHOLIPID FATTY ACIDES IN AN AEROBIC HALOGENATED HYDROCARBON-DEGRADING SOIL COLUMN ENRICHED WITH NATURAL GAS

    Science.gov (United States)

    The phospholipid ester-linked normal and lipopolysaccharide layer hydroxy fatty acids from microbes in a natural gas (85% methane)-stimulated soil column capable of degrading halogenated hydrocarbons were analyzed in detail by capillary column GC-MS. Microbial biomass, calculated...

  7. Microbial Consortium with High Cellulolytic Activity (MCHCA for enhanced biogas production.

    Directory of Open Access Journals (Sweden)

    Krzysztof ePoszytek

    2016-03-01

    Full Text Available The use of lignocellulosic biomass as a substrate in agricultural biogas plants is very popular and yields good results. However, the efficiency of anaerobic digestion, and thus biogas production, is not always satisfactory due to the slow or incomplete degradation (hydrolysis of plant matter. To enhance the solubilization of the lignocellulosic biomass various physical, chemical and biological pretreatment methods are used.The aim of this study was to select and characterize cellulose-degrading bacteria, and to construct a microbial consortium, dedicated for degradation of maize silage and enhancing biogas production from this substrate.Over one hundred strains of cellulose-degrading bacteria were isolated from: sewage sludge, hydrolyzer from an agricultural biogas plant, cattle slurry and manure. After physiological characterization of the isolates, sixteen strains (representatives of Bacillus, Providencia and Ochrobactrum genera were chosen for the construction of a Microbial Consortium with High Cellulolytic Activity, called MCHCA. The selected strains had a high endoglucanase activity (exceeding 0.21 IU/mL CMCase activity and a wide range of tolerance to various physical and chemical conditions. Lab-scale simulation of biogas production using the selected strains for degradation of maize silage was carried out in a two-bioreactor system, similar to those used in agricultural biogas plants.The obtained results showed that the constructed MCHCA consortium is capable of efficient hydrolysis of maize silage, and increases biogas production by even 38%, depending on the inoculum used for methane fermentation. The results in this work indicate that the mesophilic Microbial Consortium with High Cellulolytic Activity has a great potential for application on industrial scale in agricultural biogas plants.

  8. A phosphorus-free anolyte to enhance coulombic efficiency of microbial fuel cells

    Science.gov (United States)

    Tang, Xinhua; Li, Haoran; Du, Zhuwei; Ng, How Yong

    2014-12-01

    In this study, a phosphorus-free anolyte is prepared by using bicarbonate to replace phosphate buffer for application in two chamber microbial fuel cells (MFCs). Optical density test and Bradford protein assay shows that this phosphorus-free anolyte effectively inhibits the growth and reproduction of microorganisms suspended in the solution and greatly reduces the suspended cell mass. As a result, it considerably enhances the coulombic efficiency (CE) of MFCs. When the acetate concentration is 11 mM, the CE of the MFC using the pH 7 phosphate-containing anolyte is 9.7% and the CE with the pH 8.3 phosphate-containing anolyte is 9.1%, while the CE of the MFC using the phosphorus-free anolyte (pH 8.3) achieves 26.6%. This study demonstrates that this phosphorus-free anolyte holds the potential to enhance the feasibility for practical applications of MFCs.

  9. Microbially-Enhanced Coal Bed Methane: Strategies for Increased Biogenic Production

    Science.gov (United States)

    Davis, K.; Barhart, E. P.; Schweitzer, H. D.; Cunningham, A. B.; Gerlach, R.; Hiebert, R.; Fields, M. W.

    2014-12-01

    Coal is the largest fossil fuel resource in the United States. Most of this coal is deep in the subsurface making it costly and potentially dangerous to extract. However, in many of these deep coal seams, methane, the main component of natural gas, has been discovered and successfully harvested. Coal bed methane (CBM) currently accounts for approximately 7.5% of the natural gas produced in the U.S. Combustion of natural gas produces substantially less CO2 and toxic emissions (e.g. heavy metals) than combustion of coal or oil thereby making it a cleaner energy source. In the large coal seams of the Powder River Basin (PRB) in southeast Montana and northeast Wyoming, CBM is produced almost entirely by biogenic processes. The in situ conversion of coal to CBM by the native microbial community is of particular interest for present and future natural gas sources as it provides the potential to harvest energy from coal seams with lesser environmental impacts than mining and burning coal. Research at Montana State University has shown the potential for enhancing the subsurface microbial processes that produce CBM. Long-term batch enrichments have investigated the methane enhancement potential of yeast extract as well as algal and cyanobacterial biomass additions with increased methane production observed with all three additions when compared to no addition. Future work includes quantification of CBM enhancement and normalization of additions. This presentation addresses the options thus far investigated for increasing CBM production and the next steps for developing the enhanced in situ conversion of coal to CBM.

  10. Chemical and Microbial Characterization of North Slope Viscous Oils to Assess Viscosity Reduction and Enhanced Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Shirish Patil; Abhijit Dandekar; Mary Beth Leigh

    2008-12-31

    A large proportion of Alaska North Slope (ANS) oil exists in the form of viscous deposits, which cannot be produced entirely using conventional methods. Microbially enhanced oil recovery (MEOR) is a promising approach for improving oil recovery for viscous deposits. MEOR can be achieved using either ex situ approaches such as flooding with microbial biosurfactants or injection of exogenous surfactant-producing microbes into the reservoir, or by in situ approaches such as biostimulation of indigenous surfactant-producing microbes in the oil. Experimental work was performed to analyze the potential application of MEOR to the ANS oil fields through both ex situ and in situ approaches. A microbial formulation containing a known biosurfactant-producing strain of Bacillus licheniformis was developed in order to simulate MEOR. Coreflooding experiments were performed to simulate MEOR and quantify the incremental oil recovery. Properties like viscosity, density, and chemical composition of oil were monitored to propose a mechanism for oil recovery. The microbial formulation significantly increased incremental oil recovery, and molecular biological analyses indicated that the strain survived during the shut-in period. The indigenous microflora of ANS heavy oils was investigated to characterize the microbial communities and test for surfactant producers that are potentially useful for biostimulation. Bacteria that reduce the surface tension of aqueous media were isolated from one of the five ANS oils (Milne Point) and from rock oiled by the Exxon Valdez oil spill (EVOS), and may prove valuable for ex situ MEOR strategies. The total bacterial community composition of the six different oils was evaluated using molecular genetic tools, which revealed that each oil tested possessed a unique fingerprint indicating a diverse bacterial community and varied assemblages. Collectively we have demonstrated that there is potential for in situ and ex situ MEOR of ANS oils. Future work

  11. Spectral Induced Polarization (SIP) monitoring during Microbial Enhanced Oil Recovery (MEOR)

    Science.gov (United States)

    Heenan, J. W.; Ntarlagiannis, D.; Slater, L. D.

    2010-12-01

    Jeffrey Heenan, Dimitrios Ntarlagiannis, Lee Slater Department of Earth and Environmental Sciences, Rutgers University, Newark NJ Microbial Enhanced Oil Recovery (MEOR) is an established, cost effective, method for enhancing tertiary oil recovery. Although not commonly used for shallow heavy oils, it could be a viable alternative since it can offer sustainable economic recovery and minimal environmental impact. A critical component of successful MEOR treatments is accurate, real time monitoring of the biodegradation processes resulting from the injection of microbial communities into the formation; results of recent biogeophysical research suggest that minimally-invasive geophysical methods could significantly contribute to such monitoring efforts. Here we present results of laboratory experiments, to assess the sensitivity of the spectral induced polarization method (SIP) to MEOR treatments. We used heavy oil, obtained from a shallow oilfield in SW Missouri, to saturate three sand columns. We then followed common industry procedures,and used a commercially available microbial consortia, to treat the oil columns. The active MEOR experiments were performed in duplicate while a control column maintained similar conditions, without promoting microbial activity and oil degradation. We monitored the SIP signatures, between 0.001 Hz and 1000 Hz, for a period of six months. To support the geophysical measurements we also monitored common geochemical parameters, including pH, Eh and fluid conductivity, and collected weekly fluid samples from the outflow and inflow for further analysis; fluid samples were analyzed to confirm that microbes actively degraded the heavy oils in the column while destructive analysis of the solid materials was performed upon termination of the experiment. Preliminary analysis of the results suggests that SIP is sensitive to MEOR processes. In both inoculated columns we recorded an increase in the low frequency polarization with time; measureable

  12. 不同微生物菌剂对玉米秸秆好氧堆肥效果的影响%Effects of Different Microbial Inoculants on Aerobic Composting of Corn Stalk

    Institute of Scientific and Technical Information of China (English)

    冯致; 李杰; 张国斌; 李雯琳; 贾豪语; 刘赵帆; 郁继华

    2013-01-01

    This study was committed to screen out the suitable corn stalk single fermentation mi-crobial inoculants on the northwest desert region of non-cultivated land in an aerobic composting test. Three representative microbial inoculants (microbial inoculant 1 is mainly consisted of cellulose fungus and degraded starch bacillus;microbial inoculant 2 is mainly consisted of Bacillus subtilis,Strepto-myces tendae,Streptomyces albogriseolus,Aspergillus niger and Trichoderma reesei;microbial inoculant 3 is mainly consisted of dozens microorganisms and bio-enzyme) were selected to do the com-post experiment on corn stalk,not adding inoculants for the control check. The stacking temperature, moisture content,pH,germination seed index and other factors were surveyed and analyzed during the composting. The results show that adding microbial inoculants can effectively speed up the fermentation. The effects are better than that without addition.The temperatures of adding microbial inoculant 1 and microbial inoculant 3 treatments are relatively higher,which rose to 55 °C after 2 days.High tempera-ture lasted for 27 and 33 days,respectively.In the microbial inoculant 2 treatment,high temperature had short duration.The seed germination index was over 80% after 30 d,when treated by microbial inoculant 1 and microbial inoculant 3,while the CK needed 40 d.The total organic carbon contents of various treatments showed a downward trend,when fermentation was implemented. Treatment of micro-bial inoculant 3 had the fastest speed for organic carbon degradation.The pH values of all treatments were within the scope suitable for matured compost.We can summarize that the effect of microbial in-oculant 3 is the best,microbial inoculant 1 is second and microbial inoculant 2 is worst.%  为了筛选适合西北非耕地荒漠区玉米秸秆单一发酵的微生物菌剂,以不添加菌剂为对照,研究了3种微生物菌剂(菌剂1主要由纤维素菌和降解淀

  13. Aerobic granular processes: Current research trends.

    Science.gov (United States)

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

    2016-06-01

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

  14. Enhancement of Electricity Production by Graphene Oxide in Soil Microbial Fuel Cells and Plant Microbial Fuel Cells

    OpenAIRE

    Goto, Yuko; Yoshida, Naoko; Umeyama, Yuto; Yamada, Takeshi; Tero, Ryugo; Hiraishi, Akira

    2015-01-01

    The effects of graphene oxide (GO) on electricity generation in soil microbial fuel cells (SMFCs) and plant microbial fuel cell (PMFCs) were investigated. GO at concentrations ranging from 0 to 1.9 g⋅kg−1 was added to soil and reduced for 10 days under anaerobic incubation. All SMFCs (GO-SMFCs) utilizing the soils incubated with GO produced electricity at a greater rate and in higher quantities than the SMFCs which did not contain GO. In fed-batch operations, the overall average electricity g...

  15. Enhanced biofilm distribution and cell performance of microfluidic microbial fuel cells with multiple anolyte inlets.

    Science.gov (United States)

    Yang, Yang; Ye, Dingding; Liao, Qiang; Zhang, Pengqing; Zhu, Xun; Li, Jun; Fu, Qian

    2016-05-15

    A laminar-flow controlled microfluidic microbial fuel cell (MMFC) is considered as a promising approach to be a bio-electrochemical system (BES). But poor bacterial colonization and low power generation are two severe bottlenecks to restrict its development. In this study, we reported a MMFC with multiple anolyte inlets (MMFC-MI) to enhance the biofilm formation and promote the power density of MMFCs. Voltage profiles during the inoculation process demonstrated MMFC-MI had a faster start-up process than the conventional microfluidic microbial fuel cell with one inlet (MMFC-OI). Meanwhile, benefited from the periodical replenishment of boundary layer near the electrode, a more densely-packed bacterial aggregation was observed along the flow direction and also the substantially low internal resistance for MMFC-MI. Most importantly, the output power density of MMFC-MI was the highest value among the reported µl-scale MFCs to our best knowledge. The presented MMFC-MI appears promising for bio-chip technology and extends the scope of microfluidic energy. PMID:26735875

  16. Effects of nitrate injection on microbial enhanced oil recovery and oilfield reservoir souring.

    Science.gov (United States)

    da Silva, Marcio Luis Busi; Soares, Hugo Moreira; Furigo, Agenor; Schmidell, Willibaldo; Corseuil, Henry Xavier

    2014-11-01

    Column experiments were utilized to investigate the effects of nitrate injection on sulfate-reducing bacteria (SRB) inhibition and microbial enhanced oil recovery (MEOR). An indigenous microbial consortium collected from the produced water of a Brazilian offshore field was used as inoculum. The presence of 150 mg/L volatile fatty acids (VFA´s) in the injection water contributed to a high biological electron acceptors demand and the establishment of anaerobic sulfate-reducing conditions. Continuous injection of nitrate (up to 25 mg/L) for 90 days did not inhibit souring. Contrariwise, in nitrogen-limiting conditions, the addition of nitrate stimulated the proliferation of δ-Proteobacteria (including SRB) and the associated sulfide concentration. Denitrification-specific nirK or nirS genes were not detected. A sharp decrease in water interfacial tension (from 20.8 to 14.5 mN/m) observed concomitantly with nitrate consumption and increased oil recovery (4.3 % v/v) demonstrated the benefits of nitrate injection on MEOR. Overall, the results support the notion that the addition of nitrate, at this particular oil reservoir, can benefit MEOR by stimulating the proliferation of fortuitous biosurfactant-producing bacteria. Higher nitrate concentrations exceeding the stoichiometric volatile fatty acid (VFA) biodegradation demands and/or the use of alternative biogenic souring control strategies may be necessary to warrant effective SRB inhibition down gradient from the injection wells. PMID:25149457

  17. The in situ microbial enhanced oil recovery in fractured porous media

    Energy Technology Data Exchange (ETDEWEB)

    Soudmand-asli, Alireza; Ayatollahi, S. Shahab; Zareie, Maryam [School of Chemical and Petroleum Engineering, Shiraz University, Shiraz (Iran); Mohabatkar, Hassan [Department of Biology, School of Sciences, Shiraz University, Shiraz (Iran); Shariatpanahi, S. Farzad [Department of Chemical Engineering, Faculty of Engineering, University of Tehran, Tehran (Iran)

    2007-08-15

    These experiments aim to investigate the microbial enhanced oil recovery (MEOR) technique in fractured porous media using etched-glass micromodels. Three identically patterned micromodels with different fracture angle orientation of inclined, vertical and horizontal with respect to the flow direction were utilized. A non-fractured model was also used to compare the efficiency of MEOR in fractured and non-fractured porous media. Two types of bacteria were employed: Bacillus subtilis (a biosurfactant-producing bacterium) and Leuconostoc mesenteroides (an exopolymer-producing bacterium). The results show that higher oil recovery efficiency can be achieved by using biosurfactant-producing bacterium in fractured porous media. Further investigation on the effect of the mentioned bacteria on oil viscosity, porous media permeability and wettability suggests that the plugging of matrix-fracture interfaces by an exopolymer is the main reason for the low performance of the exopolymer-producing bacterium. Oil viscosity reduction as well as the reduction of IFT was also found to be the reason for better microbial recovery efficiencies of biosurfactant-producing bacterium in the fractured models. (author)

  18. Microbial mechanisms of using enhanced ecological floating beds for eutrophic water improvement.

    Science.gov (United States)

    Wu, Qing; Hu, Yue; Li, Shuqun; Peng, Sen; Zhao, Huabing

    2016-07-01

    Enhanced ecological floating beds were implemented to reduce nutrient quantity and improve the water quality of a eutrophic lake. The results showed that average removal efficiencies of CODCr, total nitrogen, NH3-N and total phosphorus for Canna indica L. set-up were 23.1%, 15.3%, 18.1% and 19.4% higher, respectively, than that of the setup with only substrate, and 14.2%, 12.8%, 7.9% and 11.9% higher than Iris pseudacorus L. ecological floating bed. The microbial community structure had obvious differences between devices and low similarity; bacteria were mainly attached on the fiber filling. The microbial population was abundant at the start and end of the experiment. Shannon index of samples selected ranged from 0.85 to 1.05. The sequencing results showed that fiber filling collected most uncultured bacteria species and the majority of bacteria on the plant roots were β-Proteobacteria and α-Proteobacteria. The co-dominant species attaching to the filling and plant was Nitrosomonadaceae. PMID:27035477

  19. Evaluation of In-situ Sludge Reduction and Enhanced Nutrient Removal in an Integrated Repeatedly Coupling Aerobic and Anaerobic and Oxic-setting-anaerobic System

    Institute of Scientific and Technical Information of China (English)

    Shanshan Yang; Wanqian Guo; Qinglian Wu; Haichao Luo; Simai Peng; Heshan Zheng; Xiaochi Feng; Nanqi Ren∗

    2015-01-01

    Aiming to achieve simultaneous good performances of in⁃situ sludge reduction and effluent quality, an integrated repeatedly coupling aerobic and anaerobic and oxic⁃setting⁃anaerobic system ( rCAA+OSA ) is developed to reduce sludge production and enhance nutrient removal. Considering the mechanism of in⁃situ sludge reduction in this rCAA+OSA system, the combined effect of energy uncoupling metabolism and sludge cryptic growth maybe attributed to the higher reduction of biomass. Results show that the maximal sludge reduction in this rCAA+OSA system is obtained when the hydraulic retention time ( HRT ) is controlled at 6�5 h, which an increase in 16�67% reduction in excess sludge is achieved compared with OSA system ( HRT of 6�5 h) . When compared the performances of effluent qualities, the enhanced nutrient removal efficiencies also can be observed in this rCAA+OSA system. Three⁃dimensional excitation emission matrix ( 3D⁃EEM ) fluorescence spectroscopy is applied to characterize the effluent organic matters ( EfOM) under different HRTs in the OSA and the rCAA+OSA systems. Analyses of 3D⁃EEM spectra show that more refractory humic⁃like and fulvic⁃like components are observed in the effluent of the OSA system. On the basis of these results, simultaneous enhanced in⁃situ sludge reduction and improved nutrient removal can be obtained in the rCAA+OSA systems.

  20. Mathematical modeling of the soaking period in a microbial enhanced oil recovery application

    Energy Technology Data Exchange (ETDEWEB)

    Behlulgil, K. [Middle East Technical University, Ankara (Turkey). Petroleum and Natural Gas Engineering Dept.; Durgut, I. [Norwegian University of Science and Technology, Trondheim (Norway). Petroleum Engineering and Applied Geophysics Dept.

    2003-09-01

    In this study, experimental conditions of the microbial enhanced oil recovery (MEOR) technique applied for Garzan oil (26{sup o} API; southeast Turkey) were utilized in a mathematical model that describes the transport of bacteria and its nutrients by convective and dispersive forces, including bacterial decay and growth. From the results of the variation of bacterial concentration with distance, it was observed that the bacterial concentration increased as the nutrients were consumed with time. Although some bacteria died during the experiments, this did not slow down the overall increase in bacterial population significantly at earlier times. However, in the later periods of the soaking process, severe bacterial decay occurred due to the lack of nutrients. The pressure behavior in the model during the shut-in period was also calculated and agreed well with the experimental results. (author)

  1. Enhancement of microbial motility due to speed-dependent nutrient absorption

    CERN Document Server

    Di Salvo, Mario E

    2013-01-01

    Marine microorganisms often reach high swimming speeds, either to take advantage of evanescent nutrient patches or to beat Brownian forces. Since this implies that a sizable part of their energetic budget must be allocated to motion, it is reasonable to assume that some fast-swimming microorganisms may increase their nutrient intake by increasing their speed v. We formulate a model to investigate this hypothesis and its consequences, finding the steady state solutions and analyzing their stability. Surprisingly, we find that even modest increases in nutrient absorption may lead to a significant increase of the microbial speed. In fact, evaluations obtained using realistic parameter values for bacteria indicate that the speed increase due to the enhanced nutrient absorption may be quite large.

  2. Enhancement of microbial motility due to speed-dependent nutrient absorption

    International Nuclear Information System (INIS)

    Marine microorganisms often reach high swimming speeds, either to take advantage of evanescent nutrient patches or to beat Brownian forces. Since this implies that a sizable part of their energetic budget must be allocated to motion, it is reasonable to assume that some fast-swimming microorganisms may increase their nutrient intake by increasing their speed v. We formulate a model to investigate this hypothesis and its consequences, finding the steady-state solutions and analyzing their stability. Surprisingly, we find that even modest increases in nutrient absorption may lead to a significant increase of the microbial speed. In fact, evaluations obtained using realistic parameter values for bacteria indicate that the speed increase due to the enhanced nutrient absorption may be quite large. (paper)

  3. Copper catalysis for enhancement of cobalt leaching and acid utilization efficiency in microbial fuel cells.

    Science.gov (United States)

    Liu, Yaxuan; Shen, Jingya; Huang, Liping; Wu, Dan

    2013-11-15

    Enhancement of both cobalt leaching from LiCoO2 and acid utilization efficiency (AUE) in microbial fuel cells (MFCs) was successfully achieved by the addition of Cu(II). A dosage of 10mg/L Cu(II) improved both cobalt leaching up to 308% and AUE of 171% compared to the controls with no presence of Cu(II). The apparent activation energy of cobalt leaching catalyzed by Cu(II) in MFCs was only 11.8 kJ/mol. These results demonstrate cobalt leaching in MFCs using Cu(II) as a catalyst may be an effective strategy for cobalt recovery and recycle of spent Li-ion batteries, and the evidence of influence factors including solid/liquid ratio, temperature, and pH and solution conductivity can contribute to improving understanding of and optimizing cobalt leaching catalyzed by Cu(II) in MFCs. PMID:24007993

  4. 1D Simulations for Microbial Enhanced Oil Recovery with Metabolite Partitioning

    DEFF Research Database (Denmark)

    Nielsen, Sidsel Marie; Shapiro, Alexander; Michelsen, Michael Locht;

    2010-01-01

    characteristics for the water phase saturation profiles and the oil recovery curves are elucidated. However, the effect from the surfactant is not necessarily restricted to influence only interfacial tension, but it can also be an approach for changing, e.g., wettability. The distribution coefficient determines....... For all the methods, the incremental recovery is very similar, only coming from small differences in water phase saturation profiles. Overall, a significant incremental oil recovery can be achieved, when the sensitive parameters in the context of MEOR are carefully dealt with.......We have developed a mathematical model describing the process of microbial enhanced oil recovery (MEOR). The one-dimensional isothermal model comprises displacement of oil bywater containing bacteria and substrate for their feeding. The bacterial products are both bacteria andmetabolites. In the...

  5. Influence of thermophilic aerobic digestion as a sludge pre-treatment and solids retention time of mesophilic anaerobic digestion on the methane production, sludge digestion and microbial communities in a sequential digestion process.

    Science.gov (United States)

    Jang, Hyun Min; Cho, Hyun Uk; Park, Sang Kyu; Ha, Jeong Hyub; Park, Jong Moon

    2014-01-01

    In this study, the changes in sludge reduction, methane production and microbial community structures in a process involving two-stage thermophilic aerobic digestion (TAD) and mesophilic anaerobic digestion (MAD) under different solid retention times (SRTs) between 10 and 40 days were investigated. The TAD reactor (RTAD) was operated with a 1-day SRT and the MAD reactor (RMAD) was operated at three different SRTs: 39, 19 and 9 days. For a comparison, control MAD (RCONTROL) was operated at three different SRTs of 40, 20 and 10 days. Our results reveal that the sequential TAD-MAD process has about 42% higher methane production rate (MPR) and 15% higher TCOD removal than those of RCONTROL when the SRT decreased from 40 to 20 days. Denaturing gradient gel electrophoresis (DGGE) and real-time PCR results indicate that RMAD maintained a more diverse bacteria and archaea population compared to RCONTROL, due to the application of the biological TAD pre-treatment process. In RTAD, Ureibacillus thermophiles and Bacterium thermus were the major contributors to the increase in soluble organic matter. In contrast, Methanosaeta concilii, a strictly aceticlastic methanogen, showed the highest population during the operation of overall SRTs in RMAD. Interestingly, as the SRT decreased to 20 days, syntrophic VFA oxidizing bacteria, Clostridium ultunense sp., and a hydrogenotrophic methanogen, Methanobacterium beijingense were detected in RMAD and RCONTROL. Meanwhile, the proportion of archaea to total microbe in RMAD and RCONTROL shows highest values of 10.5 and 6.5% at 20-d SRT operation, respectively. Collectively, these results demonstrate that the increased COD removal and methane production at different SRTs in RMAD might be attributed to the increased synergism among microbial species by improving the hydrolysis of the rate limiting step in sludge with the help of the biological TAD pre-treatment. PMID:23871253

  6. Microbial Consortium with High Cellulolytic Activity (MCHCA) for Enhanced Biogas Production

    Science.gov (United States)

    Poszytek, Krzysztof; Ciezkowska, Martyna; Sklodowska, Aleksandra; Drewniak, Lukasz

    2016-01-01

    The use of lignocellulosic biomass as a substrate in agricultural biogas plants is very popular and yields good results. However, the efficiency of anaerobic digestion, and thus biogas production, is not always satisfactory due to the slow or incomplete degradation (hydrolysis) of plant matter. To enhance the solubilization of the lignocellulosic biomass various physical, chemical and biological pretreatment methods are used. The aim of this study was to select and characterize cellulose-degrading bacteria, and to construct a microbial consortium, dedicated for degradation of maize silage and enhancing biogas production from this substrate. Over 100 strains of cellulose-degrading bacteria were isolated from: sewage sludge, hydrolyzer from an agricultural biogas plant, cattle slurry and manure. After physiological characterization of the isolates, 16 strains (representatives of Bacillus, Providencia, and Ochrobactrum genera) were chosen for the construction of a Microbial Consortium with High Cellulolytic Activity, called MCHCA. The selected strains had a high endoglucanase activity (exceeding 0.21 IU/mL CMCase activity) and a wide range of tolerance to various physical and chemical conditions. Lab-scale simulation of biogas production using the selected strains for degradation of maize silage was carried out in a two-bioreactor system, similar to those used in agricultural biogas plants. The obtained results showed that the constructed MCHCA consortium is capable of efficient hydrolysis of maize silage, and increases biogas production by even 38%, depending on the inoculum used for methane fermentation. The results in this work indicate that the mesophilic MCHCA has a great potential for application on industrial scale in agricultural biogas plants. PMID:27014244

  7. Sophorolipids Production by Candida bombicola ATCC 22214 and its Potential Application in Microbial Enhanced Oil Recovery

    Science.gov (United States)

    Elshafie, Abdulkadir E.; Joshi, Sanket J.; Al-Wahaibi, Yahya M.; Al-Bemani, Ali S.; Al-Bahry, Saif N.; Al-Maqbali, Dua’a; Banat, Ibrahim M.

    2015-01-01

    Biosurfactant production using Candida bombicola ATCC 22214, its characterization and potential applications in enhancing oil recovery were studied at laboratory scale. The seed media and the production media were standardized for optimal growth and biosurfactant production. The production media were tested with different carbon sources: glucose (2%w/v) and corn oil (10%v/v) added separately or concurrently. The samples were collected at 24 h interval up to 120 h and checked for growth (OD660), and biosurfactant production [surface tension (ST) and interfacial tension (IFT)]. The medium with both glucose and corn oil gave better biosurfactant production and reduced both ST and IFT to 28.56 + 0.42mN/m and 2.13 + 0.09mN/m, respectively within 72 h. The produced biosurfactant was quite stable at 13–15% salinity, pH range of 2–12, and at temperature up to 100°C. It also produced stable emulsions (%E24) with different hydrocarbons (pentane, hexane, heptane, tridecane, tetradecane, hexadecane, 1-methylnaphthalene, 2,2,4,4,6,8-heptamethylnonane, light and heavy crude oil). The produced biosurfactant was extracted using ethyl acetate and characterized as a mixture of sophorolipids (SPLs). The potential of SPLs in enhancing oil recovery was tested using core-flooding experiments under reservoir conditions, where additional 27.27% of residual oil (Sor) was recovered. This confirmed the potential of SPLs for applications in microbial enhanced oil recovery. PMID:26635782

  8. BIOTIGER, A NATURAL MICROBIAL PRODUCT FOR ENHANCED HYDROCARBON RECOVERY FROM OIL SANDS.

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R; Topher Berry, T; Whitney Jones, W; Charles Milliken, C

    2008-05-27

    BioTiger{trademark} is a unique microbial consortia that resulted from over 8 years of extensive microbiology screening and characterization of samples collected from a century-old Polish waste lagoon. BioTiger{trademark} shows rapid and complete degradation of aliphatic and aromatic hydrocarbons, produces novel surfactants, is tolerant of both chemical and metal toxicity and shows good activity at temperature and pH extremes. Although originally developed and used by the U.S. Department of Energy for bioremediation of oil-contaminated soils, recent efforts have proven that BioTiger{trademark} can also be used to increase hydrocarbon recovery from oil sands. This enhanced ex situ oil recovery process utilizes BioTiger{trademark} to optimize bitumen separation. A floatation test protocol with oil sands from Ft. McMurray, Canada was used for the BioTiger{trademark} evaluation. A comparison of hot water extraction/floatation test of the oil sands performed with BioTiger{trademark} demonstrated a 50% improvement in separation as measured by gravimetric analysis in 4 h and a five-fold increase at 25 hr. Since BioTiger{trademark} performs well at high temperatures and process engineering can enhance and sustain metabolic activity, it can be applied to enhance recovery of hydrocarbons from oil sands or other complex recalcitrant matrices.

  9. Regular Exercise Enhances the Immune Response Against Microbial Antigens Through Up-Regulation of Toll-like Receptor Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Qishi Zheng

    2015-09-01

    Full Text Available Background/Aims: Regular physical exercise can enhance resistance to many microbial infections. However, little is known about the mechanism underlying the changes in the immune system induced by regular exercise. Methods: We recruited members of a university badminton club as the regular exercise (RE group and healthy sedentary students as the sedentary control (SC group. We investigated the distribution of peripheral blood mononuclear cell (PBMC subsets and functions in the two groups. Results: There were no significant differences in plasma cytokine levels between the RE and SC groups in the true resting state. However, enhanced levels of IFN-γ, TNF-α, IL-6, IFN-α and IL-12 were secreted by PBMCs in the RE group following microbial antigen stimulation, when compared to the SC group. In contrast, the levels of TNF-α and IL-6 secreted by PBMC in the RE group were suppressed compared with those in SC group following non-microbial antigen stimulation (concanavalin A or α-galactosylceramide. Furthermore, PBMC expression of TLR2, TLR7 and MyD88 was significantly increased in the RE group in response to microbial antigen stimulation. Conclusion: Regular exercise enhances immune cell activation in response to pathogenic stimulation leading to enhanced cytokine production mediated via the TLR signaling pathways.

  10. Enhancement of electricity production by graphene oxide in soil microbial fuel cells and plant microbial fuel cells

    Directory of Open Access Journals (Sweden)

    Yuko eGoto

    2015-04-01

    Full Text Available The effects of graphene oxide (GO on electricity generation in soil microbial fuel cells (SMFCs and plant microbial fuel cell (PMFCs were investigated. GO at concentrations ranging from 0 to 1.9 g•kg-1 was added to soil and reduced for 10 days under anaerobic incubation. All SMFCs (GO-SMFCs utilizing the soils incubated with GO produced electricity at a greater rate and in higher quantities than the SMFCs which did not contain GO. In fed-batch operations, the overall average electricity generation in GO-SMFCs containing 1.0 g•kg-1 of GO was 40 ± 19 mW•m-2, which was significantly higher than the value of 6.6 ± 8.9 mW•m-2 generated from GO-free SMFCs (p -2 of electricity after 27 days of operation. Collectively, this study demonstrates that GO added to soil can be microbially reduced in soil, and facilitates electron transfer to the anode in both SMFCs and PMFCs.

  11. Dynamic changes of the dominant functioning microbial community in the compost of a 90-m(3) aerobic solid state fermentor revealed by integrated meta-omics.

    Science.gov (United States)

    Zhang, Lili; Zhang, Huaiqiang; Wang, Zhiheng; Chen, Guanjun; Wang, Lushan

    2016-03-01

    The dynamic changes in the composition and function of both bacterial and fungal communities over time and at various depths in the compost of a 90-m(3) industrial-scale fermentor were explored using integrated meta-omics. The microbial communities in the middle layer (1.2m) of the compost developed a stable and simple structure over time, which was mainly composed of Thermobifida, Bacillus, Thermomyces and Aspergillus. According to the metaproteomic results, the bacterial community was more focused on cellulose degradation, characterized by 44% of the cellulases that were secreted by Thermobifida, while the fungal community was more likely to degrade hemicellulose, mainly via Thermomyces and Aspergillus. The results revealed that, under artificial control of the temperature and oxygen concentration, the efficiency of organic waste degradation was greatly increased and the fermentation cycle was shortened to 11days. PMID:26720133

  12. Aerobic training alone or combined with strength training affects fitness in elderly

    DEFF Research Database (Denmark)

    Burich, Rasmus; Teljigović, Sanel; Boyle, Eleanor;

    2015-01-01

    PURPOSE: To investigate if combined strength and aerobic training can enhance aerobic capacity in the elderly to a similar extent as aerobic training alone when training duration is matched. METHODS: Elderly men and women (age 63.2 ± 4.7) were randomized into two intervention groups: an aerobic...... subsequently to the aerobic training. Combined training additionally improves strength and self-assessed general health more than aerobic training alone....

  13. Enhanced bioelectricity harvesting in microbial fuel cells treating food waste leachate produced from biohydrogen fermentation.

    Science.gov (United States)

    Choi, Jeongdong; Ahn, Youngho

    2015-05-01

    Microbial fuel cells (MFCs) treating the food waste leachate produced from biohydrogen fermentation were examined to enhance power generation and energy recovery. In batch mode, the maximum voltage production was 0.56 V and the power density reached 1540 mW/m(2). The maximum Coulombic efficiency (CEmax) and energy efficiency (EE) in the batch mode were calculated to be 88.8% and 18.8%, respectively. When the organic loading rate in sequencing batch mode varied from 0.75 to 6.2 g COD/L-d (under CEmax), the maximum power density reached 769.2 mW/m(2) in OLR of 3.1 g COD/L-d, whereas higher energy recovery (CE=52.6%, 0.346 Wh/g CODrem) was achieved at 1.51 g COD/L-d. The results demonstrate that readily biodegradable substrates in biohydrogen fermentation can be effectively used for the enhanced bioelectricity harvesting of MFCs and a MFC coupled with biohydrogen fermentation is of great benefit on higher electricity generation and energy efficiency. PMID:25723127

  14. A microbial fluidized electrode electrolysis cell (MFEEC) for enhanced hydrogen production

    KAUST Repository

    Liu, Jia

    2014-12-01

    A microbial fluidized electrode electrolysis cell (MFEEC) was used to enhance hydrogen gas production from dissolved organic matter. Flowable granular activated carbon (GAC) particles were used to provide additional surface area for growth of exoelectrogenic bacteria. The use of this exoelectrogenic biofilm on the GAC particles with fluidization produced higher current densities and hydrogen gas recoveries than controls (no recirculation or no GAC), due to intermittent contact of the capacitive particles with the anode. The total cumulative charge of 1688C m-2 with the MFEEC reactor (a recirculation flow rate of 19 mL min-1) was 20% higher than that of the control reactor (no GAC). The highest hydrogen gas yield of 0.82 ± 0.01 mol-H2/mol-acetate (17 mL min-1) was 39% higher than that obtained without recirculation (0.59 ± 0.01 mol-H 2/mol-acetate), and 116% higher than that of the control (no GAC, without recirculation). These results show that flowable GAC particles provide a useful approach for enhancing hydrogen gas production in bioelectrochemical systems. © 2014 Elsevier B.V. All rights reserved.

  15. Designer-Wet Micromodels for Studying Potential Changes in Wettability during Microbial Enhanced Oil Recovery

    Science.gov (United States)

    Armstrong, R. T.; Wildenschild, D.

    2010-12-01

    Microbial Enhanced Oil Recovery (MEOR) is a process where microorganisms are used for tertiary recovery of oil. Some bacteria can facilitate the mobilization of oil through the production of amphiphilic compounds called biosurfactants that reduce the interfacial tension (IFT) between immiscible phases. Additionally, most bacteria have an inclination to colonize surfaces and form biofilm, which can change a reservoir's wetting properties or clog preferential flow paths. Herein, we aim to understand changes in wettability during MEOR under mixed wettability conditions within silicon etched micromodels and to identify the type of oil field (i.e. based on wettability) in which MEOR is likely to be most profitable. To quantify porous media wettability, macro-scale indexes (obtained with techniques such as the Carter or Amott methods) are used regularly. However, these measurements lack the capability for characterization of changes in wettability during MEOR treatment, and only provide macro-scale information. In an effort to understand micro-scale temporal and spatial changes in wettability we measure interfacial curvature from stereo microscope images using level set methods. Curvature, from the perspective of the oil phase, is positive for a concave interface (i.e. water-wet surface) and negative for a convex interface (i.e. oil-wet surface). Thus, shifts in the radius of curvature distribution (i.e. from positive to negative or conversely) are indicative of wettability changes. Both curvature distributions using level-set methods and the Carter method are used to characterize wettability before and after microbial treatment. In preliminary studies aimed at understanding wettability changes due to microbial surface interactions by Bacillus mojavensis JF-2, oil droplets were placed on glass slides suspended in growth media and the resulting contact angle was measured over time. Results showed that a water-wet surface will become more water wet as JF-2 accumulated in

  16. Enhancing microbial iron reduction in hyperalkaline, chromium contaminated sediments by pH amendment

    International Nuclear Information System (INIS)

    Soil collected from beneath a chromite ore processing residue (COPR) disposal site contained a diverse population of anaerobic alkaliphiles, despite receiving a continuous influx of a Cr(VI) contaminated, hyperalkaline leachate (pH 12.2). Chromium was found to have accumulated in this soil as a result of an abiotic reaction of Cr(VI) with Fe(II) present in the soil. This sediment associated Fe(II) was, therefore, acting as a natural reactive zone beneath the COPR and thereby preventing the spread of Cr(VI). In anaerobic microcosm experiments soil microorganisms were able to reduce NO3- at pH 11.2 coupled to the oxidation of electron donors derived from the original soil organic matter, but progressive anoxia did not develop to the point of Fe reduction over a period of 9 months. It is not clear, therefore, if Fe(II) can be actively replenished by microbial processes occurring within the soil at in situ conditions. Sodium bicarbonate was added to this soil to investigate whether bioreduction of Fe in hyperalkaline Cr contaminated soils could be enhanced by reducing the pH to a value optimal for many alkaliphilic bacteria. The addition of NaHCO3 produced a well buffered system with a pH of ∼9.3 and Fe reducing conditions developed within 1 month once complete denitrification had occurred. Fe(III) reduction was associated with an increase in the proportion of genetic clone libraries that were from the phylum Firmicutes, suggesting that these species are responsible for the Fe(III) reduction observed. Amendment of the pH using bicarbonate may provide a suitable strategy for stimulating the bioreduction of Fe(III) in COPR leachate contaminated soils or other environments where microbial reduction is inhibited by elevated pH.

  17. Variability in aerobic methane oxidation over the past 1.2 Myrs recorded in microbial biomarker signatures from Congo fan sediments

    Science.gov (United States)

    Talbot, Helen M.; Handley, Luke; Spencer-Jones, Charlotte L.; Dinga, Bienvenu Jean; Schefuß, Enno; Mann, Paul J.; Poulsen, John R.; Spencer, Robert G. M.; Wabakanghanzi, Jose N.; Wagner, Thomas

    2014-05-01

    Methane (CH4) is a strong greenhouse gas known to have perturbed global climate in the past, especially when released in large quantities over short time periods from continental or marine sources. It is therefore crucial to understand and, if possible, quantify the individual and combined response of these variable methane sources to natural climate variability. However, past changes in the stability of greenhouse gas reservoirs remain uncertain and poorly constrained by geological evidence. Here, we present a record from the Congo fan of a highly specific bacteriohopanepolyol (BHP) biomarker for aerobic methane oxidation (AMO), 35-aminobacteriohopane-30,31,32,33,34-pentol (aminopentol), that identifies discrete periods of increased AMO as far back as 1.2 Ma. Fluctuations in the concentration of aminopentol, and other 35-aminoBHPs, follow a pattern that correlates with late Quaternary glacial-interglacial climate cycles, with highest concentrations during warm periods. We discuss possible sources of aminopentol, and the methane consumed by the precursor methanotrophs, within the context of the Congo River setting, including supply of methane oxidation markers from terrestrial watersheds and/or marine sources (gas hydrate and/or deep subsurface gas reservoir). Compound-specific carbon isotope values of -30‰ to -40‰ for BHPs in ODP 1075 and strong similarities between the BHP signature of the core and surface sediments from the Congo estuary and floodplain wetlands from the interior of the Congo River Basin, support a methanotrophic and likely terrigenous origin of the 35-aminoBHPs found in the fan sediments. This new evidence supports a causal connection between marine sediment BHP records of tropical deep sea fans and wetland settings in the feeding river catchments, and thus tropical continental hydrology. Further research is needed to better constrain the different sources and pathways of methane emission. However, this study identifies the large potential

  18. Estabilidade aeróbica de silagens de capim-elefante (Pennisetum purpureum, Schum emurchecido e tratado com inoculante microbiano Aerobic stability of wilted grass silages (Pennisetum Purpureum, Schum. treated with microbial inoculant

    Directory of Open Access Journals (Sweden)

    Adriana Guim

    2002-11-01

    Full Text Available Para avaliar o efeito de um inoculante microbiano sobre a estabilidade aeróbica de silagens de capim-elefante (Pennisetum purpureum, Schum pré-seco, foi conduzido um experimento na UNESP, Campus de Jaboticabal. O capim foi cortado com 96 dias de crescimento, permanecendo sob ação do sol, por aproximadamente 5 horas para o emurchecimento. Foram confeccionados silagens, em barricas plásticas de 200 L de capacidade, que receberam (CI ou não (SI o inoculante no momento da ensilagem. Para o estudo da deterioração aeróbica, na abertura dos silos (T0, cada barrica foi subdividida em três profundidades e as silagens expostas ao ar em um sistema, usado para a determinação de CO2, por 2 (T2, 4 (T4, 6 (T6 e 8 (T8 dias. A silagem da camada superficial não apresentou diferenças no valor de pH e contagem de leveduras, em relação à da camada intermediária, porém ambas apresentaram valores superiores à camada mais profunda. O teor de N-NH3 da camada superior foi menor que o da intermediária e profunda, que não diferiram entre si. A interação significativa entre inóculo e tempo de exposição mostrou que nos primeiros tempos de aeração (T0; T2 e T4 as silagens inoculadas não diferiram das controle em termos de pH, teor de N-NH3 e contagem de bolores, mas com avanço do tempo (T6 e T8 passaram a apresentar menor valor de pH, menor contagem de fungos e tendência a menor produção de CO2, indicando menor velocidade de deterioração após seis dias de exposição aeróbica.An experiment was carried out at UNESP, Jaboticabal Campus to evaluate the effect of a microbial inoculant on aerobic stability of wilted grass silage (Pennisetum purpureum, Schum. The grass was cut with 96 days of growing, remaining under sun action 5 hours to wilt. Silages were made in plastic silos, 0.2m³ capacity, that received (CI or not (SI inoculant at the ensilage time. For the study of aerobic deterioration, each silo was subdivided in three levels and the

  19. Formation of aerobic granules in the presence of a synthetic chelating agent

    International Nuclear Information System (INIS)

    This paper examines the development of aerobic granular sludge in the presence of a synthetic chelating agent, nitrilotriacetic acid (NTA), in sequencing batch reactors (SBR). The growth of seed sludge at 0.26 mM, 0.52 mM and 1.05 mM of NTA was found to be significantly lower as compared to that in the absence of NTA. Aerobic granulation was significantly enhanced in the three SBRs (R2, R3 and R4), which were fed with 0.26 mM, 0.52 mM and 1.05 mM of NTA as a co-substrate, in comparison to the acetate-alone fed SBR (R1). After 2 months of operation, the mean diameter of the biomass stabilized at 0.35 mm in R1 (acetate alone), as compared to 2.18 mm in R4 (1.05 mM NTA + acetate). NTA degradation was established in SBRs, with almost complete removal during the SBR cycle. Batch experiments also showed efficient degradation of NTA by the aerobic granules. - Synthetic chelating agent enhances aerobic microbial granulation

  20. Formation of aerobic granules in the presence of a synthetic chelating agent

    Energy Technology Data Exchange (ETDEWEB)

    Nancharaiah, Yarlagadda V. [Water and Steam Chemistry Division, Chemistry Group, Bhabha Atomic Research Centre, BARC Facilities, Kalpakkam 603 102 (India)], E-mail: yvn@igcar.ernet.in; Joshi, Hiren M.; Krishna Mohan, Tulsi V.; Venugopalan, Vayalam P.; Narasimhan, Sevilimedu V. [Water and Steam Chemistry Division, Chemistry Group, Bhabha Atomic Research Centre, BARC Facilities, Kalpakkam 603 102 (India)

    2008-05-15

    This paper examines the development of aerobic granular sludge in the presence of a synthetic chelating agent, nitrilotriacetic acid (NTA), in sequencing batch reactors (SBR). The growth of seed sludge at 0.26 mM, 0.52 mM and 1.05 mM of NTA was found to be significantly lower as compared to that in the absence of NTA. Aerobic granulation was significantly enhanced in the three SBRs (R2, R3 and R4), which were fed with 0.26 mM, 0.52 mM and 1.05 mM of NTA as a co-substrate, in comparison to the acetate-alone fed SBR (R1). After 2 months of operation, the mean diameter of the biomass stabilized at 0.35 mm in R1 (acetate alone), as compared to 2.18 mm in R4 (1.05 mM NTA + acetate). NTA degradation was established in SBRs, with almost complete removal during the SBR cycle. Batch experiments also showed efficient degradation of NTA by the aerobic granules. - Synthetic chelating agent enhances aerobic microbial granulation.

  1. Treatment of anthraquinone dye wastewater by hydrolytic acidification-aerobic process

    Institute of Scientific and Technical Information of China (English)

    YANG Jian; WU Min; Li Dan

    2004-01-01

    Experiment on microbial degradation with two kinds of biological process, hydrolytic acidification-aerobic process and aerobic process was conducted to treat the anthraquinone dye wastewater with CODCr concentration of 400 mg/L and chroma 800. The experimental result demonstrated that the hydrolytic-aerobic process could raise the biodegradability of anthraquinone dye wastewater effectively. The effluent CODCr can reach 120-170 mg/L and chroma 150 which is superior to that from simple aerobic process.

  2. Impact of butyrate on microbial selection in enhanced biological phosphorus removal systems.

    Science.gov (United States)

    Begum, Shamim A; Batista, Jacimaria R

    2014-01-01

    Microbial selection in an enhanced biological phosphorus removal system was investigated in a laboratory-scale sequencing batch reactor fed exclusively with butyrate as a carbon source. As reported in the few previous studies, butyrate uptake was slow and phosphorus (P) release occurred during the entire anaerobic period. Polyphosphate-accumulating organism (PAO), i.e. Candidatus Accumulibacter phosphatis (named as Accumulibacter), glycogen-accumulating organisms (GAOs), i.e. Candidatus Competibacter phosphatis (named as Competibacter) and Defluviicoccus-related, tetrad-forming alphaproteobacteria (named as Defluviicoccus) were identified using fluorescence in situ hybridization analysis. The results show that Accumulibacter and Defluviicoccus were selected in the butyrate-fed reactor, whereas Competibacter was not selected. P removal was efficient at the beginning of the experiment with an increasing percentage relative abundance (% RA) of PAOs. The % RA of Accumulibacter and Defluviicoccus increased from 13% to 50% and 8% to 16%, respectively, and the % RA of Competibacter decreased from 8% to 2% during the experiment. After 6 weeks, P removal deteriorated with the poor correlation between the percentage of P removal and % RA of GAOs. PMID:25189844

  3. Potential Enhancement of Plant Iron Assimilation by Microbial-Induced Root Exudation of Phenolic Compounds

    Directory of Open Access Journals (Sweden)

    Cheng Zhou

    2016-03-01

    Full Text Available Iron (Fe deficiency in crop plants is a modern agricultural problem worldwide. Although multiple strategies have been evolved to improve Fe assimilation, some plant species, especially dicots and nongraminaceous monocots (strategy I plants, cannot avoid Fe deficiency in low Fe-availability soils. It is well documented that graminaceous plants (strategy II plants employ the chelationbased Fe acquisition, and the strategy I plants use the reduction-based strategy to take up Fe. Intriguingly, under Fe deficiency the strategy I plants have recently been found to acquire Fe via exudation of phenolic compounds to mobilize Fe, which is much similar to the chelation-based mechanism of strategy II plants. Hitherto, increasing evidence has shown that soil microbes play a cooperative role in plant Fe acquisition. Several beneficial rhizobacteria have been found to increase plant Fe accumulation via activation of the reduction-based strategy. Moreover, microbial-induced root exudation of phenolic compounds can also promote plant Fe absorption by efficient mobilization of Fe, which increases Fe bioavailability in calcareous soils. Here, we briefly review the recent progress on the Fe assimilation strategies of strategy I and II plants, and further discuss the possible mechanisms underlying soil microbes enhance plant Fe acquisition.

  4. Identification of bacteria used for microbial enhanced oil recovery process by fluorescence in situ hybridization technique

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, K.; Tanaka, S.; Otsuka, M. [Kansai Research Institute, Kyoto (Japan). Lifescience Lab.; Yonebayashi, H. [Japan National Oil Corp., Chiba (Japan). Tech. Research Center; Enomoto, H. [Tohoku University, Sendai (Japan). Dept. of Geoscience and Tech.

    2000-01-01

    A fluorescence in situ hybridization (FISH) technique using 16S rRNA-targeted oligonucleotide probes was developed for rapid detection of microorganisms for use in the microbial enhancement of oil recovery (MEOR) process. Two microorganisms, Enterobacter cloacae TRC-322 and Bacillus licheniformis TRC-18-2-a, were selected from a collection of Enterobacter sp. and Bacillus sp. which were screened in previous studies as candidate microorganisms for injection, and were used for this experiment. Oligonucleotide probes, design based on specific sequences in the 16S rRNA gene were labeled with either fluorescein isothiocyanate (FITC), or 6-car-boxy-X-rhodamine (ROX), and were allowed to hybridize with fixed cells of the two microorganisms noted above. The fluorescence signal emitted from each microorganism cells could clearly be detected by an epifluorescence microscope. Moreover, E. cloacae TRC-322 and B, licheniformis TRC-18-2-a, suspended in actual reservoir brine, including inorganic salts, oil and aboriginal cells of the reservoir brine, could be detected directly by this hybridization method, without the need for cultivation and isolation. (author)

  5. The Application Of Microbial Enhanced Oil Recovery On Unconventional Oil: A Field Specific Approach

    Science.gov (United States)

    Goodman, Sean; Millar, Andrew; Allison, Heather; McCarthy, Alan

    2014-05-01

    A substantial amount of the world's recoverable oil reserves are made from unconventional or heavy resources. However, great difficulty has been had in recovering this oil after primary and secondary recovery methods have been employed. Therefore, tertiary methods such as microbial enhanced oil recovery (MEOR) have been employed. MEOR involves the use of bacteria and their metabolic products to alter the oil properties or rock permeability within a reservoir in order to promote the flow of oil. Although MEOR has been trialed in the past with mixed outcomes, its feasibility on heavier oils has not been demonstrated. The aim of this study is to show that MEOR can be successfully applied to unconventional oils. By using an indigenous strain of bacteria isolated from a reservoir of interest and applied to field specific microcosms, we will look into the effect of these bacteria compared to variant inoculums to identify which mechanisms of action the bacteria are using to improve recovery. Using this information, we will be able to identify genes of interest and groups of bacteria that may be beneficial for MEOR and look accurately identify favorable bacteria within a reservoir.

  6. Microbial Enhanced Oil Recovery in Fractional-Wet Systems: A Pore-Scale Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Ryan T.; Wildenschild, Dorthe (Oregon State U.)

    2012-10-24

    Microbial enhanced oil recovery (MEOR) is a technology that could potentially increase the tertiary recovery of oil from mature oil formations. However, the efficacy of this technology in fractional-wet systems is unknown, and the mechanisms involved in oil mobilization therefore need further investigation. Our MEOR strategy consists of the injection of ex situ produced metabolic byproducts produced by Bacillus mojavensis JF-2 (which lower interfacial tension (IFT) via biosurfactant production) into fractional-wet cores containing residual oil. Two different MEOR flooding solutions were tested; one solution contained both microbes and metabolic byproducts while the other contained only the metabolic byproducts. The columns were imaged with X-ray computed microtomography (CMT) after water flooding, and after MEOR, which allowed for the evaluation of the pore-scale processes taking place during MEOR. Results indicate that the larger residual oil blobs and residual oil held under relatively low capillary pressures were the main fractions recovered during MEOR. Residual oil saturation, interfacial curvatures, and oil blob sizes were measured from the CMT images and used to develop a conceptual model for MEOR in fractional-wet systems. Overall, results indicate that MEOR was effective at recovering oil from fractional-wet systems with reported additional oil recovered (AOR) values between 44 and 80%; the highest AOR values were observed in the most oil-wet system.

  7. Enhanced surface functionality and microbial fuel cell performance of chitosan membranes through phosphorylation.

    Science.gov (United States)

    Holder, Shima L; Lee, Ching-Hwa; Popuri, Srinivasa R; Zhuang, Meng-Xin

    2016-09-20

    The effects of plasticization and cross-linking on the performance of chitosan as promising proton exchange membranes (PEMs) for bioelectricity generation in microbial fuel cells (MFCs) were investigated. The physico-chemical properties of chitosan (CS), sorbitol-chitosan (S-CS), phosphorylated-chitosan (CS-P) and phosphorylated-sorbitol-chitosan (S-CS-P) membranes were investigated by FESEM-EDS, FTIR-ATR, XRD, TGA, tensile strength and sorption studies. The performance of the fabricated PEMs was assessed by power density and cation exchange capacity (CEC). Maximum power densities achieved were 130.03, 20.76, 94.59 and 7.42mW/m(2) for CS-P, S-CS-P, S-CS and CS membranes respectively. Phosphorylation of the CS membranes increased CEC and tensile strength, attributed to an increase in bonded amide and phosphate ionic surface groups. Further, 49.07% COD removal from municipal wastewater was achieved with CS-P membranes. Thus, through chemical modifications, the physico-chemical and mechanical properties of natural abundant biopolymer chitosan can be enhanced for its use as an environmentally sustainable PEM in MFC technology. PMID:27261749

  8. Plant carbohydrate binding module enhances activity of hybrid microbial cellulase enzyme

    Directory of Open Access Journals (Sweden)

    Caitlin Siobhan Byrt

    2012-11-01

    Full Text Available A synthetic, highly active cellulase enzyme suitable for in planta production may be a valuable tool for biotechnological approaches to develop transgenic biofuel crops with improved digestibility. Here, we demonstrate that the addition of a plant derived carbohydrate binding module (CBM to a synthetic glycosyl hydrolase (GH improved the activity of the hydrolase in releasing sugar from plant biomass. A CEL-HYB1-CBM enzyme was generated by fusing a hybrid microbial cellulase, CEL-HYB1, with the carbohydrate-binding module (CBM of the tomato (Solanum lycopersicum SlCel9C1 cellulase. CEL-HYB1 and CEL-HYB1-CBM enzymes were produced in vitro using Pichia pastoris and the activity of these enzymes was tested using CMC, MUC and native crystalline cellulose assays. The presence of the CBM substantially improved the endo-glucanase activity of CEL-HYB1, especially against the native crystalline cellulose encountered in Sorghum plant cell walls. These results indicate that addition of an endogenous plant derived CBM to cellulase enzymes may enhance hydrolytic activity.

  9. Experimental and numerical simulation study of microbial enhanced oil recovery using bio-surfactants

    Science.gov (United States)

    Maudgalya, Saikrishna

    An experimental and numerical study were conducted to investigate the ability of bio-surfactant produced by the microbe Bacillus mojavensis strain JF-2 to recover residual oil from consolidated porous media. Experiments showed that the bio-surfactant at concentrations as low as 40.0 ppm. (0.04 mg/scc) and viscosified with 1000.0 ppm of polymer could recover 10.0 % to 40.0 % of residual oil when injected through sandstone cores at typical field rates. A 2-phase, 10-component microbial enhanced oil recovery numerical simulator was modified to include reservoir salinity and facilitate surfactant and polymer injection. The effects of reservoir brine salinity and divalent ion effects on bio-surfactant and polymer adsorption, polymer retention, polymer viscosity, bio-surfactant interfacial tension and the shear rate effect on polymer viscosity were added to the simulator. Core flood experiments where JF-2 bio-surfactant viscosified with partially hydrolyzed polyacrylamide was injected into Berea cores at waterflood residual oil saturation were simulated. The effects of brine salinity and hardness on surfactant and polymer behavior were tested and the core flood simulation results compared with the experimental results. After the laboratory and simulation studies, a residual oil recovery method based on non-aqueous phase liquid (NAPL) contaminant removal from aquifers is discussed and functional form of the transport equation presented. In this method, residual oil is treated as another chemical species dispersed in porous media instead of a phase that is uniformly distributed across the media.

  10. Enhanced nitrogen removal in single-chamber microbial fuel cells with increased gas diffusion areas

    KAUST Repository

    Yan, Hengjing

    2012-11-23

    Single-chamber microbial fuel cells (MFCs) with nitrifiers pre-enriched at the air cathodes have previously been demonstrated as a passive strategy for integrating nitrogen removal into current-generating bioelectrochemical systems. To further define system design parameters for this strategy, we investigated in this study the effects of oxygen diffusion area and COD/N ratio in continuous-flow reactors. Doubling the gas diffusion area by adding an additional air cathode or a diffusion cloth significantly increased the ammonia and COD removal rates (by up to 115% and 39%), ammonia removal efficiency (by up to 134%), the cell voltage and cathode potentials, and the power densities (by a factor of approximately 2). When the COD/N ratio was lowered from 13 to 3, we found up to 244% higher ammonia removal rate but at least 19% lower ammonia removal efficiency. An increase of COD removal rate by up to 27% was also found when the COD/N ratio was lowered from 11 to 3. The Coulombic efficiency was not affected by the additional air cathode, but decreased by an average of 11% with the addition of a diffusion cloth. Ammonia removal by assimilation was also estimated to understand the ammonia removal mechanism in these systems. These results showed that the doubling of gas diffusion area enhanced N and COD removal rates without compromising electrochemical performance. © 2012 Wiley Periodicals, Inc.

  11. Diversity Enhances NPP, N Retention, and Soil Microbial Diversity in Experimental Urban Grassland Assemblages

    Science.gov (United States)

    Thompson, Grant L.; Kao-Kniffin, Jenny

    2016-01-01

    Urban grasslands, landscapes dominated by turfgrasses for aesthetic or recreational groundcovers, are rapidly expanding in the United States and globally. These managed ecosystems are often less diverse than the natural or agricultural lands they replace, leading to potential losses in ecosystem functioning. Research in non-urban systems has provided evidence for increases in multiple ecosystem functions associated with greater plant diversity. To test if biodiversity-ecosystem function findings are applicable to urban grasslands, we examined the effect of plant species and genotypic diversity on three ecosystem functions, using grassland assemblages of increasing diversity that were grown within a controlled environment facility. We found positive effects of plant diversity on reduced nitrate leaching and plant productivity. Soil microbial diversity (Mean Shannon Diversity, H’) of bacteria and fungi were also enhanced in multi-species plantings, suggesting that moderate increments in plant diversity influence the composition of soil biota. The results from this study indicate that plant diversity impacts multiple functions that are important in urban ecosystems; therefore, further tests of urban grassland biodiversity should be examined in situ to determine the feasibility of manipulating plant diversity as an explicit landscape design and function trait. PMID:27243768

  12. Enhanced Activated Carbon Cathode Performance for Microbial Fuel Cell by Blending Carbon Black

    KAUST Repository

    Zhang, Xiaoyuan

    2014-02-04

    Activated carbon (AC) is a useful and environmentally sustainable catalyst for oxygen reduction in air-cathode microbial fuel cells (MFCs), but there is great interest in improving its performance and longevity. To enhance the performance of AC cathodes, carbon black (CB) was added into AC at CB:AC ratios of 0, 2, 5, 10, and 15 wt % to increase electrical conductivity and facilitate electron transfer. AC cathodes were then evaluated in both MFCs and electrochemical cells and compared to reactors with cathodes made with Pt. Maximum power densities of MFCs were increased by 9-16% with CB compared to the plain AC in the first week. The optimal CB:AC ratio was 10% based on both MFC polarization tests and three electrode electrochemical tests. The maximum power density of the 10% CB cathode was initially 1560 ± 40 mW/m2 and decreased by only 7% after 5 months of operation compared to a 61% decrease for the control (Pt catalyst, 570 ± 30 mW/m2 after 5 months). The catalytic activities of Pt and AC (plain or with 10% CB) were further examined in rotating disk electrode (RDE) tests that minimized mass transfer limitations. The RDE tests showed that the limiting current of the AC with 10% CB was improved by up to 21% primarily due to a decrease in charge transfer resistance (25%). These results show that blending CB in AC is a simple and effective strategy to enhance AC cathode performance in MFCs and that further improvement in performance could be obtained by reducing mass transfer limitations. © 2014 American Chemical Society.

  13. Enhanced U(VI) release from autunite mineral by aerobic Arthrobacter sp. in the presence of aqueous bicarbonate

    Energy Technology Data Exchange (ETDEWEB)

    Katsenovich, Yelena; Carvajal, Denny A.; Wellman, Dawn M.; Lagos, Leonel

    2012-04-20

    The bacterial effect on U(VI) leaching from the autunite mineral (Ca[(UO{sub 2})(PO{sub 4})]{sub 2} {center_dot} 3H{sub 2}O) was investigated to provide a more comprehensive understanding into important microbiological processes affecting autunite stability within subsurface bicarbonate-bearing environments. Experiments were performed in a culture of G975 Arthrobacter oxydans strain, herein referred to as G975, a soil bacterium previously isolated from Hanford Site soil. 91 mg of autunite powder and 50 mL of phosphorus-limiting sterile media were amended with bicarbonate ranging between 1-10 mM in glass reactor bottles and inoculated with G975 strain after the dissolution of autunite was at steady state. SEM observations indicated G975 formed a biofilm on the autunite surface and penetrated the mineral cleavages. The mineral surface colonization by bacteria tended to increase concomitantly with bicarbonate concentrations. Additionally, a sterile cultureware with inserts was used in non-contact bioleaching experiments where autunite and bacteria cells were kept separately. The data suggest the G975 bacteria is able to enhance U(VI) leaching from autunite without the direct contact with the mineral. In the presence of bicarbonate, the damage to bacterial cells caused by U(VI) toxicity was reduced, yielding similar values for total organic carbon (TOC) degradation and cell density compared to U(VI)-free controls. The presence of active bacterial cells greatly enhanced the U(VI) bioleaching from autunite in bicarbonate-amended media.

  14. Aerobic exercise (image)

    Science.gov (United States)

    Aerobic exercise gets the heart working to pump blood through the heart more quickly and with more force than ... must be oxygenated more quickly, which quickens respiration. Aerobic exercise strengthens the heart and boosts healthy cholesterol ...

  15. Bacterial cellulose-polyaniline nano-biocomposite: A porous media hydrogel bioanode enhancing the performance of microbial fuel cell

    Science.gov (United States)

    Mashkour, Mehrdad; Rahimnejad, Mostafa; Mashkour, Mahdi

    2016-09-01

    Microbial fuel cells (MFCs) are one of the possible renewable energy supplies which microorganisms play an active role in bio-oxidize reactions of a substrate such as glucose. Electrode materials and surface modifications are highly effective tools in enhancing MFCs' Performance. In this study, new composite anodes are fabricated. Bacterial cellulose (BC) is used as continuous phase and polyaniline (PANI) as dispersed one which is synthesized by in situ chemical oxidative polymerization on BC's fibers. With hydrogel nature of BC as a novel feature and polyaniline conductivity there meet the favorable conditions to obtain an active microbial biofilm on anode surface. Maximum power density of 117.76 mW/m2 in current density of 617 mA/m2 is achieved for BC/PANI anode. The amounts demonstrate a considerable enhancement compared with graphite plate (1 mW/m2 and 10 mA/m2).

  16. Microbial and Chemical Enhancement of In-Situ Carbon Mineralization in Geological Formation

    Energy Technology Data Exchange (ETDEWEB)

    Matter, J.; Chandran, K.

    2013-05-31

    Predictions of global energy usage suggest a continued increase in carbon emissions and rising concentrations of CO{sub 2} in the atmosphere unless major changes are made to the way energy is produced and used. Various carbon capture and storage (CCS) technologies are currently being developed, but unfortunately little is known regarding the fundamental characteristics of CO{sub 2}-mineral reactions to allow a viable in-situ carbon mineralization that would provide the most permanent and safe storage of geologically-injected CO{sub 2}. The ultimate goal of this research project was to develop a microbial and chemical enhancement scheme for in-situ carbon mineralization in geologic formations in order to achieve long-term stability of injected CO{sub 2}. Thermodynamic and kinetic studies of CO{sub 2}-mineral-brine systems were systematically performed to develop the in-situ mineral carbonation process that utilizes organic acids produced by a microbial reactor. The major participants in the project are three faculty members and their graduate and undergraduate students at the School of Engineering and Applied Science and at the Lamont-Doherty Earth Observatory at Columbia University: Alissa Park in Earth and Environmental Engineering & Chemical Engineering (PI), Juerg Matter in Earth and Environmental Science (Co-PI), and Kartik Chandran in Earth and Environmental Engineering (Co-PI). Two graduate students, Huangjing Zhao and Edris Taher, were trained as a part of this project as well as a number of graduate students and undergraduate students who participated part-time. Edris Taher received his MS degree in 2012 and Huangjing Zhao will defend his PhD on Jan. 15th, 2014. The interdisciplinary training provided by this project was valuable to those students who are entering into the workforce in the United States. Furthermore, the findings from this study were and will be published in referred journals to disseminate the results. The list of the papers is given at

  17. Teaching Aerobic Fitness Concepts.

    Science.gov (United States)

    Sander, Allan N.; Ratliffe, Tom

    2002-01-01

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

  18. Microbial Enhanced Heavy Oil Recovery by the Aid of Inhabitant Spore-Forming Bacteria: An Insight Review

    OpenAIRE

    Biji Shibulal; Al-Bahry, Saif N.; Al-Wahaibi, Yahya M.; Elshafie, Abdulkader E.; Al-Bemani, Ali S.; Joshi, Sanket J.

    2014-01-01

    Crude oil is the major source of energy worldwide being exploited as a source of economy, including Oman. As the price of crude oil increases and crude oil reserves collapse, exploitation of oil resources in mature reservoirs is essential for meeting future energy demands. As conventional recovery methods currently used have become less efficient for the needs, there is a continuous demand of developing a new technology which helps in the upgradation of heavy crude oil. Microbial enhanced oil...

  19. Gas Production Generated from Crude Oil Biodegradation: Preliminary Study on its Aplication in Microbial Enhanced Oil Recovery (MEOR)

    OpenAIRE

    Astri Nugroho

    2009-01-01

    Gas Production Generated from Crude Oil Biodegradation: Preliminary Study on its Aplication in MicrobialEnhanced Oil Recovery (MEOR). The objective of this study is to observe the capacity of gas production generatedfrom crude oil degradation by the isolated bacteria. The gas in the MEOR could increase pressure in the reservoir,decrease oil viscosity, increase oil permeability-due to the increase of the porosity and viscosity, and also increase oilvolume due to the amount of dissolved gas. A ...

  20. Surface Area Expansion of Electrodes with Grass-like Nanostructures to Enhance Electricity Generation in Microbial Fuel Cells

    OpenAIRE

    Al Atraktchi, Fatima Al-Zahraa; Zhang, Yifeng; Safaa Noori, Jafar; Angelidaki, Irini

    2012-01-01

    Microbial fuel cells (MFCs) have applications possibilities for wastewater treatment, biotransformation, and biosensor, but the development of highly efficient electrode materials is critical for enhancing the power generation. Two types of electrodes modified with nanoparticles or grass-like nanostructure (termed nanograss) were used. A two-chamber MFC with plain silicium electrodes achieved a maximum power density of 0.002 mW/m2, while an electrode with nanograss of titanium and gold deposi...

  1. Selection of Bacteria with Favorable Transport Properties Through Porous Rock for the Application of Microbial-Enhanced Oil Recovery

    OpenAIRE

    Jang, Long-Kuan; Chang, Philip W.; Findley, John E.; Yen, Teh Fu

    1983-01-01

    This paper presents a bench-scale study on the transport in highly permeable porous rock of three bacterial species—Bacillus subtilis, Pseudomonas putida, and Clostridium acetobutylicum—potentially applicable in microbial-enhanced oil recovery processes. The transport of cells during the injection of bacterial suspension and nutrient medium was simulated by a deep bed filtration model. Deep bed filtration coefficients and the maximum capacity of cells in porous rock were measured. Low to inte...

  2. Production of microbial rhamnolipid by Pseudomonas aeruginosa MM1011 for ex situ enhanced oil recovery.

    Science.gov (United States)

    Amani, Hossein; Müller, Markus Michael; Syldatk, Christoph; Hausmann, Rudolf

    2013-07-01

    Recently, several investigations have been carried out on the in situ bacteria flooding, but the ex situ biosurfactant production and addition to the sand pack as agents for microbial enhanced oil recovery (MEOR) has little been studied. In order to develop suitable technology for ex situ MEOR processes, it is essential to carry out tests about it. Therefore, this work tries to fill the gap. The intention of this study was to investigate whether the rhamnolipid mix could be produced in high enough quantities for enhanced oil recovery in the laboratory scale and prove its potential use as an effective material for field application. In this work, the ability of Pseudomonas aeruginosa MM1011 to grow and produce rhamnolipid on sunflower as sole carbon source under nitrogen limitation was shown. The production of Rha-C10-C10 and Rha2-C10-C10 was confirmed by thin-layer chromatography and high-performance liquid chromatography analysis. The rhamnolipid mixture obtained was able to reduce the surface and interfacial tension of water to 26 and 2 mN/m, respectively. The critical micelle concentration was 120 mg/L. Maximum rhamnolipid production reached to about 0.7 g/L in a shake flask. The yield of rhamnolipid per biomass (Y RL/x ), rhamnolipid per sunflower oil (Y RL/s ), and the biomass per sunflower oil (Y x/s ) for shake flask were obtained about 0.01, 0.0035, and 0.035 g g(-1), respectively. The stability of the rhamnolipid at different salinities, pH and temperature, and also, its emulsifying activity has been investigated. It is an effective surfactant at very low concentrations over a wide range of temperatures, pHs, and salt concentrations, and it also has the ability to emulsify oil, which is essential for enhanced oil recovery. With 120 mg/L rhamnolipid, 27 % of original oil in place was recovered after water flooding from a sand pack. This result not only suggests rhamnolipids as appropriate model biosurfactants for MEOR, but it even shows the potential as a

  3. Enhancement of microbial quality and inactivation of pathogenic bacteria by gamma irradiation of ready-to-cook Iranian barbecued chicken

    Energy Technology Data Exchange (ETDEWEB)

    Fallah, Aziz A., E-mail: a_a_falah@yahoo.co [Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Shahre-Kord University, Shahre-Kord 34141 (Iran, Islamic Republic of); Research Institute of Zoonotic Diseases, Shahre-Kord University, Shahre-Kord 34141 (Iran, Islamic Republic of); Siavash Saei-Dehkordi, S. [Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Shahre-Kord University, Shahre-Kord 34141 (Iran, Islamic Republic of); Research Institute of Zoonotic Diseases, Shahre-Kord University, Shahre-Kord 34141 (Iran, Islamic Republic of); Rahnama, Mohammad [Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, University of Zabol, Zabol 98615 (Iran, Islamic Republic of)

    2010-10-15

    Ready-to-cook Iranian barbecued chicken consists of cubed chicken breast, lemon juice, salt, red pepper, onion, saffron and vegetable oil with an overall pH value of about 5.5. This product is sometimes consumed under-cooked, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. In this study, the effect of gamma irradiation (0, 1.5, 3 and 4.5 kGy) on the microbial quality of ready-to-cook (RTC) barbecued chicken samples stored at 4 {sup o}C for 15 days was investigated. Moreover, the effectiveness of irradiation for inactivating Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella typhimurium inoculated into the samples was also studied. Irradiation of the samples resulted in dose dependent reduction in counts of aerobic mesophilic bacteria, yeasts and molds, Enterobacteriaceae and lactic acid bacteria. Among the microbial flora, yeasts and molds and Enterobacteriaceae were more sensitive to irradiation and got completely eliminated at dose of 3 kGy. D{sub 10} values of L. monocytogenes, E. coli O157:H7 and S. typhimurium inoculated into the samples were 0.680, 0.397 and 0.601 kGy, respectively. An irradiation dose of 3 kGy reduced the counts of E. coli O157:H7 to an undetectable level in RTC barbecued chicken but was ineffective on elimination of L. monocytogenes and S. typhimurium. However, none of the food-borne pathogens were detected in the samples irradiated at 4.5 kGy. This study showed that irradiation had no undesirable effects on the initial sensory attributes of barbecued chicken. At the end of the storage period, irradiated samples were more acceptable compared to non-irradiated ones.

  4. Enhancement of microbial quality and inactivation of pathogenic bacteria by gamma irradiation of ready-to-cook Iranian barbecued chicken

    Science.gov (United States)

    Fallah, Aziz A.; Siavash Saei-Dehkordi, S.; Rahnama, Mohammad

    2010-10-01

    Ready-to-cook Iranian barbecued chicken consists of cubed chicken breast, lemon juice, salt, red pepper, onion, saffron and vegetable oil with an overall pH value of about 5.5. This product is sometimes consumed under-cooked, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. In this study, the effect of gamma irradiation (0, 1.5, 3 and 4.5 kGy) on the microbial quality of ready-to-cook (RTC) barbecued chicken samples stored at 4 °C for 15 days was investigated. Moreover, the effectiveness of irradiation for inactivating Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella typhimurium inoculated into the samples was also studied. Irradiation of the samples resulted in dose dependent reduction in counts of aerobic mesophilic bacteria, yeasts and molds, Enterobacteriaceae and lactic acid bacteria. Among the microbial flora, yeasts and molds and Enterobacteriaceae were more sensitive to irradiation and got completely eliminated at dose of 3 kGy. D10 values of L. monocytogenes, E. coli O157:H7 and S. typhimurium inoculated into the samples were 0.680, 0.397 and 0.601 kGy, respectively. An irradiation dose of 3 kGy reduced the counts of E. coli O157:H7 to an undetectable level in RTC barbecued chicken but was ineffective on elimination of L. monocytogenes and S. typhimurium. However, none of the food-borne pathogens were detected in the samples irradiated at 4.5 kGy. This study showed that irradiation had no undesirable effects on the initial sensory attributes of barbecued chicken. At the end of the storage period, irradiated samples were more acceptable compared to non-irradiated ones.

  5. Enhancement of microbial quality and inactivation of pathogenic bacteria by gamma irradiation of ready-to-cook Iranian barbecued chicken

    International Nuclear Information System (INIS)

    Ready-to-cook Iranian barbecued chicken consists of cubed chicken breast, lemon juice, salt, red pepper, onion, saffron and vegetable oil with an overall pH value of about 5.5. This product is sometimes consumed under-cooked, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. In this study, the effect of gamma irradiation (0, 1.5, 3 and 4.5 kGy) on the microbial quality of ready-to-cook (RTC) barbecued chicken samples stored at 4 oC for 15 days was investigated. Moreover, the effectiveness of irradiation for inactivating Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella typhimurium inoculated into the samples was also studied. Irradiation of the samples resulted in dose dependent reduction in counts of aerobic mesophilic bacteria, yeasts and molds, Enterobacteriaceae and lactic acid bacteria. Among the microbial flora, yeasts and molds and Enterobacteriaceae were more sensitive to irradiation and got completely eliminated at dose of 3 kGy. D10 values of L. monocytogenes, E. coli O157:H7 and S. typhimurium inoculated into the samples were 0.680, 0.397 and 0.601 kGy, respectively. An irradiation dose of 3 kGy reduced the counts of E. coli O157:H7 to an undetectable level in RTC barbecued chicken but was ineffective on elimination of L. monocytogenes and S. typhimurium. However, none of the food-borne pathogens were detected in the samples irradiated at 4.5 kGy. This study showed that irradiation had no undesirable effects on the initial sensory attributes of barbecued chicken. At the end of the storage period, irradiated samples were more acceptable compared to non-irradiated ones.

  6. The United States Culture Collection Network (USCCN): Enhancing Microbial Genomics Research through Living Microbe Culture Collections

    Energy Technology Data Exchange (ETDEWEB)

    Boundy-Mills, K.; Hess, Matthias; Bennett, A. R.; Ryan, Matthew; Kang, Seogchan; Nobles, David; Eisen, Jonathan A.; Inderbitzin, Patrik; Sitepu, Irnayuli R.; Torok, Tamas; Brown, Daniel R; Cho, Juliana; Wertz, John E.; Mukherjee, Supratim; Cady, Sherry L.; McCluskey, Kevin

    2015-09-01

    The mission of the United States Culture Collection Network (USCCN; http://usccn.org) is "to facilitate the safe and responsible utilization of microbial resources for research, education, industry, medicine, and agriculture for the betterment of human kind." Microbial culture collections are a key component of life science research, biotechnology, and emerging global biobased economies. Representatives and users of several microbial culture collections from the United States and Europe gathered at the University of California, Davis, to discuss how collections of microorganisms can better serve users and stakeholders and to showcase existing resources available in public culture collections.

  7. High quality residues from cover crops favor changes in microbial community and enhance C and N sequestration

    Directory of Open Access Journals (Sweden)

    Ileana Frasier

    2016-04-01

    Full Text Available The objective of the study was to evaluate the effect of a change in management on the soil microbial community and C sequestration. We conducted a 3-year field study in La Pampa (Argentina with rotation of sorghum (Sorghum bicolor in zero tillage alternating with rye (Secale cereale and vetch (Vicia villosa ssp. dasycarpa. Soil was sampled once a year at two depths. Soil organic matter fractions, dissolved organic matter, microbial biomass (MBC and community composition (DNA extraction, qPCR, and phospholipid FAME profiles were determined. Litter, aerial- and root biomass were collected and all material was analyzed for C and N. Results showed a rapid response of microbial biomass to a bacterial dominance independent of residue quality. Vetch had the highest diversity index, while the fertilized treatment had the lowest one. Vetch–sorghum rotation with high N mineralization rates and diverse microbial community sequestered more C and N in stable soil organic matter fractions than no-till sorghum alone or with rye, which had lower N turnover rates. These results reaffirm the importance of enhanced soil biodiversity for maintaining soil ecosystem functioning and services. The supply of high amounts of N-rich residues as provided by grass–legume cover crops could fulfill this objective.

  8. Enhanced current and power density of micro-scale microbial fuel cells with ultramicroelectrode anodes

    Science.gov (United States)

    Ren, Hao; Rangaswami, Sriram; Lee, Hyung-Sool; Chae, Junseok

    2016-09-01

    We present a micro-scale microbial fuel cell (MFC) with an ultramicroelectrode (UME) anode, with the aim of creating a miniaturized high-current/power-density converter using carbon-neutral and renewable energy sources. Micro-scale MFCs have been studied for more than a decade, yet their current and power densities are still an order of magnitude lower than those of their macro-scale counterparts. In order to enhance the current/power densities, we engineer a concentric ring-shaped UME, with a width of 20 μm, to facilitate the diffusion of ions in the vicinity of the micro-organisms that form biofilm on the UME. The biofilm extends approximately 15 μm from the edge of the UME, suggesting the effective biofilm area increases. Measured current/power densities per the effective area and the original anode area are 7.08  ±  0.01 A m‑2 & 3.09  ±  0.04 W m‑2 and 17.7  ±  0.03 A m‑2 & 7.72  ±  0.09 W m‑2, respectively. This is substantially higher than any prior work in micro-scale MFCs, and very close, or even higher, to that of macro-scale MFCs. A Coulombic efficiency, a measure of how efficiently an MFC harvests electrons from donor substrate, of 70%, and an energy conversion efficiency of 17% are marked, highlighting the micro-scale MFC as an attractive alternative within the existing energy conversion portfolio.

  9. Enhanced digestion of waste activated sludge using microbial electrolysis cells at ambient temperature.

    Science.gov (United States)

    Asztalos, Joseph R; Kim, Younggy

    2015-12-15

    This study examined the effects of the microbial electrolysis cell (MEC) reactions on anaerobic digestion of waste activated sludge from municipal wastewater treatment under ambient temperature conditions (22-23 °C). Two lab-scale digesters, a control anaerobic digester and an electrically-assisted digester (EAD - equipped with a MEC bioanode and cathode) were operated under three solids retention times (SRT = 7, 10 and 14 days) at 22.5 ± 0.5 °C. A numerical model was also built by including the MEC electrode reactions in Anaerobic Digestion Model No.1. In experiments, the EAD showed reduced concentration of acetic acid, propionic acid, n-butyric acid and iso-butyric acid. This improved performance of the EAD is thought to be achieved by direct oxidation of the short-chain fatty acids at the bioanode as well as indirect contribution of low acetic acid concentration to enhancing beta-oxidation. The VSS and COD removal was consistently higher in the EAD by 5-10% compared to the control digester for all SRT conditions at 22.5 ± 0.5 °C. When compared to mathematical model results, this additional COD removal in the EAD was equivalent to that which would be achieved with conventional digesters at mesophilic temperatures. The magnitude of electric current in the EAD was governed by the organic loading rate while conductivity and acetic acid concentration showed negligible effects on current generation. Very high methane content (∼95%) in the biogas from both the EAD and control digester implies that the waste activated sludge contained large amounts of lipids and other complex polymeric substances compared to primary sludge. PMID:26051356

  10. Shifts in microbial community structure during in situ surfactant-enhanced bioremediation of polycyclic aromatic hydrocarbon-contaminated soil.

    Science.gov (United States)

    Wang, Lingwen; Li, Feng; Zhan, Yu; Zhu, Lizhong

    2016-07-01

    This study aims to reveal the microbial mechanism of in situ surfactant-enhanced bioremediation (SEBR). Various concentrations of rhamnolipids, Tween 80, and sodium dodecyl benzenesulfonate (SDBS) were separately sprayed onto soils contaminated with polycyclic aromatic hydrocarbons (PAHs) for years. Within 90 days, the highest level of degradation (95 %) was observed in the soil treated with rhamnolipids (10 mg/kg), followed by 92 % degradation with Tween 80 (50 mg/kg) and 90 % degradation with SDBS (50 mg/kg). The results of the microbial phospholipid fatty acids (PLFAs) suggest that bacteria dominated the enhanced PAH biodegradation (94 % of the maximum contribution). The shift of bacterial community structure during the surfactant treatment was analyzed by using the 16S rRNA gene high-throughput sequencing. In the presence of surfactants, the number of the operational taxonomic units (OTUs) associated with Bacillus, Pseudomonas, and Sphingomonas increased from 2-3 to 15-30 % at the end of the experiment (two to three times of control). Gene prediction with phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) shows that the PAH-degrading genes, such as 1-hydroxy-2-naphthoate dioxygenase and PAH dioxygenase large subunit, significantly increased after the surfactant applications (p < 0.05). The findings of this study provide insights into the surfactant-induced shifts of microbial community, as well as critical factors for efficient bioremediation. PMID:27068902

  11. Community proteogenomics highlights microbial strain-variant protein expression within activated sludge performing enhanced biological phosphorus removal.

    Energy Technology Data Exchange (ETDEWEB)

    Wilmes, P [University of California, Berkeley; Andersson, Anders F. [University of California, Berkeley; Lefsrud, Mark G [McGill University, Montreal, Quebec; Wexler, Margaret [University of East Anglia, Norwich, United Kingdom; Shah, Manesh B [ORNL; Zhang, B [Vanderbilt University; Hettich, Robert {Bob} L [ORNL; Bond, P. L. [University of Queensland, The, Brisbane, Queensland, Australia; Verberkmoes, Nathan C [ORNL; Banfield, Jillian F. [University of California, Berkeley

    2008-01-01

    Enhanced biological phosphorus removal (EBPR) selects for polyphosphate accumulating organisms to achieve phosphate removal from wastewater. We used highresolution community proteomics to identify key metabolic pathways in "Candidatus Accumulibacter phosphatis"-mediated EBPR and to evaluate the contributions of co- 5 existing strains within the dominant population. Results highlight the importance of denitrification, fatty acid cycling and the glyoxylate bypass in EBPR. Despite overall strong similarity in protein profiles under anaerobic and aerobic conditions, fatty acid degradation proteins were more abundant during the anaerobic phase. By comprehensive genome-wide alignment of orthologous proteins, we uncovered strong 10 functional partitioning for enzyme variants involved in both core-metabolism and EBPR-specific pathways among the dominant strains. These findings emphasize the importance of genetic diversity in maintaining the stable performance of EBPR systems and demonstrate the power of integrated cultivation-independent genomics and proteomics for analysis of complex biotechnological systems.

  12. Enhanced long-term organics and nitrogen removal and associated microbial community in intermittently aerated subsurface flow constructed wetlands.

    Science.gov (United States)

    Fan, Jinlin; Zhang, Jian; Guo, Wenshan; Liang, Shuang; Wu, Haiming

    2016-08-01

    The long-term enhanced removal efficiency of organics and nitrogen in subsurface flow constructed wetlands (SSF CWs) with and without intermittent aeration for decentralized domestic wastewater was evaluated, and the function of intermittent aeration on microbial community was also investigated in this study. The high and long-term 95.6% COD, 96.1% NH4(+)-N and 85.8% TN removal efficiencies were achieved in experimental intermittently aerated SSF CW compared with non-aerated SSF CW. Aerated SSF CWs also exhibited the excellent removal performance when comparatively comparing with other strategies and techniques applied in CWs. In addition, fluorescence in situ hybridization (FISH) analysis revealed that associated microbial abundance significantly increased owing to intermittent aeration. These results indicated intermittent aeration CWs might be an effective and sustainable strategy for wastewater treatment in rural areas, but require further full-scale investigation in future. PMID:27246456

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

    Science.gov (United States)

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

    1998-01-01

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

  14. Mechanism of Kenaf Retting Using Aerobes

    Institute of Scientific and Technical Information of China (English)

    卢士森; 陈季华; 黄秀宝

    2001-01-01

    The experimental results showed that the duration of microbial retting processing of kenaf fibers by using aerobic microbe was four times shorter than that by using anaerobic microbe. The residual gum percentage,breaking strength, breaking elongation and linear density of aerobic retted kenaf bundle fibers did not show significantly difference with that of anaerobic retted kenaf bundle fibers by ANOVA-Tukey's studentized test at a = 5% except for the softness. The bioenergetic principle and the calculation of the amount of ATP produced during the decomposition processing of kenaf gums were used to explain why the retting duration in the case of using aerobic microbes was much shorter than that of using anaerobic microbes.

  15. Microbially-Enhanced Redox Solution Reoxidation for Sour Natural Gas Sweetening

    Energy Technology Data Exchange (ETDEWEB)

    Kenneth Brezinsky

    2008-01-15

    The specific objective of this project are to advance the technology and improve the economics of the commercial iron-based chelate processes such as LO-CAT II and SulFerox process utilizing biologically enhanced reoxidation of the redox solutions used in these processes. The project is based on the use of chelated ferric iron as the catalyst for the production of elemental sulfur, and then oxidizing bacteria, such as Thiobacillus Ferrooxidans (ATCC 23270) as an oxidizer. The regeneration of Fe{sup 3+} - chelate is accomplished by the use of these same microbes under mild conditions at 25-30 C and at atmospheric pressure to minimize the chelate degradation process. The pH of the redox solution was observed to be a key process parameter. Other parameters such as temperature, total iron concentration, gas to liquid ratio and bacterial cell densities also influence the overall process. The second part of this project includes experimental data and a kinetic model of microbial H{sub 2}S removal from sour natural gas using thiobacillus species. In the experimental part, a series of experiments were conducted with a commercial chelated iron catalyst at pH ranges from 8.7 to 9.2 using a total iron concentration range from 925 ppm to 1050 ppm in the solution. Regeneration of the solution was carried out by passing air through the solution. Iron oxidizing bacteria were used at cell densities of 2.3 x 10{sup 7}cells/ml for optimum effective performance. In the modeling part, oxidation of Fe{sup 2+} ions by the iron oxidizing bacteria - Thiobacillus Ferrooxidans was studied for application to a continuous stirred tank reactor (CSTR). The factors that can directly affect the oxidation rate such as dilution rate, temperature, and pH were analyzed. The growth of the microorganism was assumed to follow Monod type of growth kinetics. Dilution rate had influence on the rate of oxidation of ferrous iron. Higher dilution rates caused washout of the biomass. The oxidation rate was

  16. PHA Production in Aerobic Mixed Microbial Cultures

    OpenAIRE

    K. Johnson

    2010-01-01

    Polyhydroxyalkanoate (PHA) is a common intracellular energy and carbon storage material in bacteria, which is considered as a bioplastic due to its plastic like properties. PHAs are versatile materials which are biodegradable and made from renewable resources. Commercial production of PHAs is currently based on pure culture processes employing either natural PHA producers or genetically modified bacteria. Pure culture processes use generally pure sterile substrates and axenic reactors, leadin...

  17. 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.

  18. INEEL Biotechnology for Oilfield Application--Microbial Enhanced Oil Recovery FY-03 Report

    Energy Technology Data Exchange (ETDEWEB)

    G. A. Bala; D. F. Bruhn; S. L. Fox; K. S. Noah; K. D. Schaller; E. P. Robertson; X. Xie

    2003-11-01

    The Idaho National Engineering and Environmental Laboratory (INEEL) Biotechnology for Oilfield Operations program supports development, engineering, and application of biotechnology for exploration and production. This continuing INEEL program also supports mitigation of detrimental field conditions. The program is consistent with the United States Department of Energy mission to ¡§promote activities and policies through its oil technology and natural gas supply programs to enhance the efficiency and environmental quality of domestic oil and natural gas exploration, recovery, processing, transport, and storage.¡¨ In addition, the program directly supports the focus areas of Reservoir Life Extension; Advanced Drilling, Completion and Stimulation Systems; Effective Environmental Protection; and Cross Cutting Areas. The program is enhanced by collaborative relationships with industry and academia. For fiscal year 2003, the program focused on production and characterization of biological surfactants from agricultural residuals and the production and application of reactive microbial polymers. This report specifically details: 1. Use of a chemostat reactor operated in batch mode for producing surfactin, with concomitant use of an antifoam to prevent surfactant loss. The program achieved production and recovery of 0.6 g/L of surfactin per 12 hr. 2. Characterization of surfactin produced from agricultural residuals with respect to its ability to mediate changes in surface tension. Conditions evaluated were salt (as NaCl) from 0 to 10% (w/v), pH from 3 to 10, temperature from 21 to 70¢XC, and combinations of these conditions. When evaluated singularly, pH below 6 and salt concentrations above 30 g/L were found to have an adverse impact on surfactin. Temperatures of 70¢XC for 95 days had no effect. When the effect of temperature was added to the pH experiment, there were no significant changes, and, again, surface tension, at any temperature, increased at pH below 6

  19. Cucurbita spp. and Cucumis sativus enhance the dissipation of polychlorinated biphenyl congeners by stimulating soil microbial community development

    International Nuclear Information System (INIS)

    A number of Cucurbita species have the potential to extract polychlorinated biphenyls (PCBs) from soil, but their impact on the soil microbial communities responsible for PCB degradation remains unclear. A greenhouse experiment was conducted to investigate the effect of three Cucurbita and one Cucumis species on PCB dissipation and soil microbial community structure. Compared to the unplanted control, enhanced losses of PCBs (19.5%–42.7%) were observed in all planted soils. Cucurbita pepo and Cucurbita moschata treatments were more efficient in PCB dissipation, and have similar patterns of soil phospholipid fatty acids (PLFAs) and PCB congener profiles. Cucurbita treatments tend to have higher soil microbial biomass than Cucumis. Gram-negative (G−) bacteria were significantly correlated with PCB degradation rates (R2 = 0.719, p − bacteria were correlated with dissipation of the penta homologue group (R2 = 0.590, p − bacteria contributed significantly to soil PCB dissipation. • Fungi have a great potential in the dissipation of high chlorinated biphenyls. -- Cucurbita associated fungi and G− bacteria have important influence on soil PCB dissipation rate and congener profile

  20. Engineering PQS biosynthesis pathway for enhancement of bioelectricity production in Pseudomonas aeruginosa microbial fuel cells

    DEFF Research Database (Denmark)

    Wang, Victor Bochuan; Chua, Song-Lin; Cao, Bin;

    2013-01-01

    . aeruginosa strain that produces higher concentrations of phenazines under anaerobic conditions by over-expressing the PqsE effector in a PQS negative ΔpqsC mutant. The engineered strain exhibited an improved electrical performance in microbial fuel cells (MFCs) and potentiostat-controlled electrochemical...... genetic engineering is a suitable technique to improve power output of bioelectrochemical systems....

  1. Monitoring exogenous and indigenous bacteria by PCR-DGGE technology during the process of microbial enhanced oil recovery.

    Science.gov (United States)

    Wang, Jun; Ma, Ting; Zhao, Lingxia; Lv, Jinghua; Li, Guoqiang; Zhang, Hao; Zhao, Ben; Liang, Fenglai; Liu, Rulin

    2008-06-01

    A field experiment was performed to monitor changes in exogenous bacteria and to investigate the diversity of indigenous bacteria during a field trial of microbial enhanced oil recovery (MEOR). Two wells (26-195 and 27-221) were injected with three exogenous strains and then closed to allow for microbial growth and metabolism. After a waiting period, the pumps were restarted and the samples were collected. The bacterial populations of these samples were analyzed by denaturing gradient gel electrophoresis (DGGE) with PCR-amplified 16S rRNA fragments. DGGE profiles indicated that the exogenous strains were retrieved in the production water samples and indigenous strains could also be detected. After the pumps were restarted, average oil yield increased to 1.58 and 4.52 tons per day in wells 26-195 and 27-221, respectively, compared with almost no oil output before the injection of exogenous bacteria. Exogenous bacteria and indigenous bacteria contributed together to the increased oil output. Sequence analysis of the DGGE bands revealed that Proteobacteria were a major component of the predominant bacteria in both wells. Changes in the bacteria population in the reservoirs during MEOR process were monitored by molecular analysis of the 16S rRNA gene sequence. DGGE analysis was a successful approach to investigate the changes in microorganisms used for enhancing oil recovery. The feasibility of MEOR technology in the petroleum industry was also demonstrated. PMID:18273653

  2. Selection of bacteria with favorable transport properties through porous rock for the application of microbial-enhanced oil recovery.

    Science.gov (United States)

    Jang, L K; Chang, P W; Findley, J E; Yen, T F

    1983-11-01

    This paper presents a bench-scale study on the transport in highly permeable porous rock of three bacterial species-Bacillus subtilis, Pseudomonas putida, and Clostridium acetobutylicum-potentially applicable in microbial-enhanced oil recovery processes. The transport of cells during the injection of bacterial suspension and nutrient medium was simulated by a deep bed filtration model. Deep bed filtration coefficients and the maximum capacity of cells in porous rock were measured. Low to intermediate ( approximately 10/ml) injection concentrations of cellular suspensions are recommended because plugging of inlet surface is less likely to occur. In addition to their resistance to adverse environments, spores of clostridia are strongly recommended for use in microbial-enhanced oil recovery processes since they are easiest among the species tested to push through porous rock. After injection, further transport of bacteria during incubation can occur by growth and mobility through the stagnant nutrient medium which fills the porous rock. We have developed an apparatus to study the migration of bacteria through a Berea sandstone core containing nutrient medium. PMID:16346414

  3. Selection of Bacteria with Favorable Transport Properties Through Porous Rock for the Application of Microbial-Enhanced Oil Recovery

    Science.gov (United States)

    Jang, Long-Kuan; Chang, Philip W.; Findley, John E.; Yen, Teh Fu

    1983-01-01

    This paper presents a bench-scale study on the transport in highly permeable porous rock of three bacterial species—Bacillus subtilis, Pseudomonas putida, and Clostridium acetobutylicum—potentially applicable in microbial-enhanced oil recovery processes. The transport of cells during the injection of bacterial suspension and nutrient medium was simulated by a deep bed filtration model. Deep bed filtration coefficients and the maximum capacity of cells in porous rock were measured. Low to intermediate (∼106/ml) injection concentrations of cellular suspensions are recommended because plugging of inlet surface is less likely to occur. In addition to their resistance to adverse environments, spores of clostridia are strongly recommended for use in microbial-enhanced oil recovery processes since they are easiest among the species tested to push through porous rock. After injection, further transport of bacteria during incubation can occur by growth and mobility through the stagnant nutrient medium which fills the porous rock. We have developed an apparatus to study the migration of bacteria through a Berea sandstone core containing nutrient medium. PMID:16346414

  4. Molecular Analysis of Bacterial Community DNA in Sludge Undergoing Autothermal Thermophilic Aerobic Digestion (ATAD): Pitfalls and Improved Methodology to Enhance Diversity Recovery

    OpenAIRE

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

    2010-01-01

    Molecular analysis of the bacterial community structure associated with sludge processed by autothermal thermophilic aerobic digestion (ATAD), was performed using a number of extraction and amplification procedures which differed in yield, integrity, ability to amplify extracted templates and specificity in recovering species present. Interference to PCR and qPCR amplification was observed due to chelation, nuclease activity and the presence of thermolabile components derived from the ATAD sl...

  5. Combining C6 and C5 sugar metabolism for enhancing microbial bioconversion.

    Science.gov (United States)

    Zhang, Guo-Chang; Liu, Jing-Jing; Kong, In Iok; Kwak, Suryang; Jin, Yong-Su

    2015-12-01

    Mixed sugars, which are often obtained from renewable biomass, can be converted into biofuels and chemicals by microbial conversion. This sustainable production process can also mitigate man-made climate change when used to petroleum-based fuel and chemical production. In contrast to single sugar fermentations, such as corn-based or sugarcane-based ethanol fermentations, mixed sugar fermentations present significant challenges for cost-effective production of the target products. In particular, inefficient and slow microbial fermentation of non-glucose sugars, such as galactose and xylose from the depolymerization of marine and terrestrial biomass has been a major obstacle. Nonetheless, simultaneous utilization of mixed sugars has recently been demonstrated through innovative metabolic engineering strategies and the discovery of transporters, and metabolic pathways which are necessary for co-fermenting glucose and non-glucose sugars. PMID:26432418

  6. Use of Surface Enhanced Blocking (SEB) Electrodes for Microbial Cell Lysis in Flow-Through Devices

    OpenAIRE

    Talebpour, Abdossamad; Maaskant, Robert; Khine, Aye Aye; Alavie, Tino

    2014-01-01

    By simultaneously subjecting microbial cells to high amplitude pulsed electric fields and flash heating of the cell suspension fluid, effective release of intracellular contents was achieved. The synergistic effect of the applied electric field and elevated temperature on cell lysis in a flow-through device was demonstrated for Gram-negative and Gram-positive bacteria, and Mycobacterium species. The resulting lysate is suitable for downstream nucleic acid amplification and detection without r...

  7. Enhancing metaproteomics-The value of models and defined environmental microbial systems.

    Science.gov (United States)

    Herbst, Florian-Alexander; Lünsmann, Vanessa; Kjeldal, Henrik; Jehmlich, Nico; Tholey, Andreas; von Bergen, Martin; Nielsen, Jeppe Lund; Hettich, Robert L; Seifert, Jana; Nielsen, Per Halkjaer

    2016-03-01

    Metaproteomics-the large-scale characterization of the entire protein complement of environmental microbiota at a given point in time-has provided new features to study complex microbial communities in order to unravel these "black boxes." New technical challenges arose that were not an issue for classical proteome analytics before that could be tackled by the application of different model systems. Here, we review different current and future model systems for metaproteome analysis. Following a short introduction to microbial communities and metaproteomics, we introduce model systems for clinical and biotechnological research questions including acid mine drainage, anaerobic digesters, and activated sludge. Model systems are useful to evaluate the challenges encountered within (but not limited to) metaproteomics, including species complexity and coverage, biomass availability, or reliable protein extraction. The implementation of model systems can be considered as a step forward to better understand microbial community responses and ecological functions of single member organisms. In the future, improvements are necessary to fully explore complex environmental systems by metaproteomics. PMID:26621789

  8. Impact of salinity on the aerobic metabolism of phosphate-accumulating organisms.

    Science.gov (United States)

    Welles, L; Lopez-Vazquez, C M; Hooijmans, C M; van Loosdrecht, M C M; Brdjanovic, D

    2015-04-01

    The use of saline water in urban areas for non-potable purposes to cope with fresh water scarcity, intrusion of saline water, and disposal of industrial saline wastewater into the sewerage lead to elevated salinity levels in wastewaters. Consequently, saline wastewater is generated, which needs to be treated before its discharge into surface water bodies. The objective of this research was to study the effects of salinity on the aerobic metabolism of phosphate-accumulating organisms (PAO), which belong to the microbial populations responsible for enhanced biological phosphorus removal (EBPR) in activated sludge systems. In this study, the short-term impact (hours) of salinity (as NaCl) was assessed on the aerobic metabolism of a PAO culture, enriched in a sequencing batch reactor (SBR). All aerobic PAO metabolic processes were drastically affected by elevated salinity concentrations. The aerobic maintenance energy requirement increased, when the salinity concentration rose up to a threshold concentration of 2 % salinity (on a W/V basis as NaCl), while above this concentration, the maintenance energy requirements seemed to decrease. All initial rates were affected by salinity, with the NH4- and PO4-uptake rates being the most sensitive. A salinity increase from 0 to 0.18 % caused a 25, 46, and 63 % inhibition of the O2, PO4, and NH4-uptake rates. The stoichiometric ratios of the aerobic conversions confirmed that growth was the process with the highest inhibition, followed by poly-P and glycogen formation. The study indicates that shock loads of 0.18 % salt, which corresponds to the use or intrusion of about 5 % seawater may severely affect the EBPR process already in wastewater treatment plants not exposed regularly to high salinity concentrations. PMID:25524698

  9. Applying Reactive Barrier Technology to Enhance Microbially-mediated Denitrification during Managed Aquifer Recharge

    Science.gov (United States)

    Beganskas, S.; Weir, W. B.; Harmon, R. E.; Gorski, G.; Fisher, A. T.; Saltikov, C.; Young, K. S.; Runneals, D.; Teo, E. K.; Stoneburner, B.; Hernandez, J.

    2015-12-01

    We are running field experiments to observe and quantify microbially-mediated water quality improvement via denitrification during infiltration in the shallow subsurface. Nitrate is a pervasive groundwater contaminant, and nitrate removal through denitrification can occur during infiltration in natural and anthropogenic systems, including during managed aquifer recharge (MAR). The rate of denitrification can vary depending on factors such as infiltration rate; previous work suggests that denitrification rates can increase monotonically with infiltration rates until reaching a critical threshold. We are performing controlled field tests of variables that affect denitrification rate, including sampling to link water chemistry changes to microbial ecology and activity. This study explores how microbial activity and denitrification rates respond to different infiltration rates and the presence or absence of a reactive material (wood chips, a carbon source). We are conducting four two-week-long tests, each under different conditions. For each test, we measure bulk infiltration rate (the sum of lateral and vertical infiltration), vertical infiltration rate using heat as a tracer, and water level. We collect surface and subsurface water samples daily, and we collect soil samples at the start and end of each test. For each water sample, we are measuring NO3-, NO2-, NH3, DOC, and N and O isotopes in nitrate. Soil samples will be tested for grain size, total C/N, and the presence of microbiological genes associated with denitrification. These results will expand our knowledge of the conditions under which denitrification occurs by implicating specific microorganisms and physical infiltration parameters. Our design has the potential for additional experimentation with variables that impact water chemistry during infiltration. This study has broad applications for designing MAR systems that effectively improve water supply and water quality.

  10. Photosynthetic membrane-less microbial fuel cells to enhance microalgal biomass concentration.

    Science.gov (United States)

    Uggetti, Enrica; Puigagut, Jaume

    2016-10-01

    The aim of this study was to quantitatively assess the net increase in microalgal biomass concentration induced by photosynthetic microbial fuel cells (PMFC). The experiment was conducted on six lab-scale PMFC constituted by an anodic chamber simulating an anaerobic digester connected to a cathodic chamber consisting of a mixed algae consortia culture. Three PMFC were operated at closed circuit (PMFC(+)) whereas three PMFC were left unconnected as control (PMFC(-)). PMFC(+) produced a higher amount of carbon dioxide as a product of the organic matter oxidation that resulted in 1.5-3 times higher biomass concentration at the cathode compartment when compared to PMFC(-). PMID:27455126

  11. Power Generation Enhancement by Utilizing Plant Photosynthate in Microbial Fuel Cell Coupled Constructed Wetland System

    OpenAIRE

    Shentan Liu; Hailiang Song; Xianning Li; Fei Yang

    2013-01-01

    In the present study, a new technology that coupled constructed wetland (CW) with microbial fuel cell (MFC) (CW-MFC) was developed to convert solar energy into electricity on the principles of photosynthetic MFC by utilizing root exudates of Ipomoea aquatica as part of fuel. The maximum power density of 12.42 mW m−2 produced from the CW-MFC planted with Ipomoea aquatica was 142% higher than that of 5.13 mW m−2 obtained from the unplanted CW-MFC. The maximum power output for the planted CW-MFC...

  12. Succession of microbial community and enhanced mechanism of a ZVI-based anaerobic granular sludge process treating chloronitrobenzenes wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Liang, E-mail: felix79cn@hotmail.com [Department of Environmental Engineering, Zhejiang University, Hangzhou 310058 (China); Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou 310058 (China); Jin, Jie [Department of Environmental Engineering, Zhejiang University, Hangzhou 310058 (China); Lin, Haizhuan [Department of Environmental Engineering, Zhejiang University, Hangzhou 310058 (China); Wenzhou Environmental Protection Design Scientific Institute, Wenzhou 325000 (China); Gao, Kaituo [Department of Environmental Engineering, Zhejiang University, Hangzhou 310058 (China); Xu, Xiangyang, E-mail: xuxy@zju.edu.cn [Department of Environmental Engineering, Zhejiang University, Hangzhou 310058 (China); Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou 310058 (China)

    2015-03-21

    Highlights: • The combined ZVI–UASB process was established for the degradation of chloronitrobenzenes. • There were the better shock resistance and buffering capacity for anaerobic acidification in the combined process. • Novel ZVI-based anaerobic granular sludge (ZVI–AGS) was successfully developed. • Adaptive shift of microbial community was significant in ZVI-based anaerobic granular sludge system. - Abstract: The combined zero-valent iron (ZVI) and upflow anaerobic sludge blanket (UASB) process is established for the treatment of chloronitrobenzenes (ClNBs) wastewater, and the succession of microbial community and its enhanced mechanism are investigated in the study. Results showed that compared with the control UASB (R1), the stable COD removal, ClNBs transformation, and dechlorination occurred in the combined system (R2) when operated at influent COD and 3,4-Dichloronitrobenzene (3,4-DClNB) loading rates of 4200–7700 g m{sup −3} d{sup −1} and 6.0–70.0 g m{sup −3} d{sup −1}, and R2 had the better shock resistance and buffering capacity for the anaerobic acidification. The dechlorination for the intermediate products of p-chloroanaline (p-ClAn) to analine (AN) occurred in R2 reactor after 45 days, whereas it did not occur in R1 after a long-term operation. The novel ZVI-based anaerobic granular sludge (ZVI–AGS) was successfully developed in the combined system, and higher microbial activities including ClNB transformation and H{sub 2}/CH{sub 4} production were achieved simultaneously. The dominant bacteria were closely related to the groups of Megasphaera, Chloroflexi, and Clostridium, and the majority of archaea were correlated with the groups of Methanosarcinalesarchaeon, Methanosaetaconcilii, and Methanothrixsoehngenii, which are capable of reductively dechlorinating PCB, HCB, and TCE in anaerobic niche and EPS secretion.

  13. Succession of microbial community and enhanced mechanism of a ZVI-based anaerobic granular sludge process treating chloronitrobenzenes wastewater

    International Nuclear Information System (INIS)

    Highlights: • The combined ZVI–UASB process was established for the degradation of chloronitrobenzenes. • There were the better shock resistance and buffering capacity for anaerobic acidification in the combined process. • Novel ZVI-based anaerobic granular sludge (ZVI–AGS) was successfully developed. • Adaptive shift of microbial community was significant in ZVI-based anaerobic granular sludge system. - Abstract: The combined zero-valent iron (ZVI) and upflow anaerobic sludge blanket (UASB) process is established for the treatment of chloronitrobenzenes (ClNBs) wastewater, and the succession of microbial community and its enhanced mechanism are investigated in the study. Results showed that compared with the control UASB (R1), the stable COD removal, ClNBs transformation, and dechlorination occurred in the combined system (R2) when operated at influent COD and 3,4-Dichloronitrobenzene (3,4-DClNB) loading rates of 4200–7700 g m−3 d−1 and 6.0–70.0 g m−3 d−1, and R2 had the better shock resistance and buffering capacity for the anaerobic acidification. The dechlorination for the intermediate products of p-chloroanaline (p-ClAn) to analine (AN) occurred in R2 reactor after 45 days, whereas it did not occur in R1 after a long-term operation. The novel ZVI-based anaerobic granular sludge (ZVI–AGS) was successfully developed in the combined system, and higher microbial activities including ClNB transformation and H2/CH4 production were achieved simultaneously. The dominant bacteria were closely related to the groups of Megasphaera, Chloroflexi, and Clostridium, and the majority of archaea were correlated with the groups of Methanosarcinalesarchaeon, Methanosaetaconcilii, and Methanothrixsoehngenii, which are capable of reductively dechlorinating PCB, HCB, and TCE in anaerobic niche and EPS secretion

  14. Enhancing the value of nitrogen from rapeseed meal for microbial oil production.

    Science.gov (United States)

    Uçkun Kiran, Esra; Salakkam, Apilak; Trzcinski, Antoine P; Bakir, Ufuk; Webb, Colin

    2012-05-10

    Rapeseed meal, a major byproduct of biodiesel production, has been used as a low-cost raw material for the production of a generic microbial feedstock through a consolidated bioconversion process. Various strategies were tested for the production of a novel fermentation medium, rich in free amino nitrogen (FAN): commercial enzymes (CEs) (2.7 mg g⁻¹ dry meal), liquid state fungal pre-treatment (LSF) using Aspergillus oryzae (4.6 mg g⁻¹), liquid state fungal pre-treatment followed by fungal autolysis (LSFA) (9.13 mg g⁻¹), liquid state pre-treatment using fungal enzymatic broth (EB) (2.1 mg g⁻¹), but the best strategy was a solid state fungal pre-treatment followed by fungal autolysis (34.5 mg g⁻¹). The bioavailability of the nitrogen sources in the novel medium was confirmed in fed-batch bioreactor studies, in which 82.3g dry cell L⁻¹ of the oleaginous yeast Rhodosporidium toruloides Y4 was obtained with a lipid content of 48%. The dry cell weight obtained was higher than that obtained using conventional yeast extract, due to a higher total nitrogen content in the novel biomedium. The fatty acids obtained from the microbial oil were similar to those derived from rapeseed oil. PMID:22500902

  15. Enhanced water desalination efficiency in an air-cathode stacked microbial electrodeionization cell (SMEDIC)

    KAUST Repository

    Chehab, Noura A.

    2014-11-01

    A microbial desalination cell was developed that contained a stack of membranes packed with ion exchange resins between the membranes to reduce ohmic resistances and improve performance. This new configuration, called a stacked microbial electro-deionization cell (SMEDIC), was compared to a control reactor (SMDC) lacking the resins. The SMEDIC+S reactors contained both a spacer and 1.4±0.2. mL of ion exchange resin (IER) per membrane channel, while the spacer was omitted in the SMEDIC-S reactors and so a larger volume of resin (2.4±0.2. mL) was used. The overall extent of desalination using the SMEDIC with a moderate (brackish water) salt concentration (13. g/L) was 90-94%, compared to only 60% for the SMDC after 7 fed-batch cycles of the anode. At a higher (seawater) salt concentration of 35. g/L, the extent of desalination reached 61-72% (after 10 cycles) for the SMEDIC, compared to 43% for the SMDC. The improved performance was shown to be due to the reduction in ohmic resistances, which were 130. Ω (SMEDIC-S) and 180. Ω (SMEDIC+S) at the high salt concentration, compared to 210. Ω without resin (SMDC). These results show that IERs can improve performance of stacked membranes for both moderate and high initial salt concentrations. © 2014 Elsevier B.V.

  16. What Is Aerobic Dancing?

    Science.gov (United States)

    ... after exercising, see a physician. Common Aerobics Injuries Plantar fasciitis (arch pain) -- Arch pain is often caused by ... rearfoot instability, with excessive pronation, may result in plantar fasciitis. Shoes with proper support in the arch often ...

  17. [Research of aerobic granule characteristics with different granule age].

    Science.gov (United States)

    Zhou, Man; Yang, Chang-Zhu; Pu, Wen-Hong; Luo, Ying-Dong; Gong, Jian-Yu

    2012-03-01

    In the SBR reactor, we studied the different style, physicochemical characteristic, pollutants removal and microbial activity between the short age and long age aerobic granule, respectively. The short age aerobic granule was cultivated from activated floccules sludge and the other was gotten from aerobic granular sludge which was operated stably more than one year. The results indicated that the wet density, the specific gravity and integrated coefficient (IC) of the short age aerobic granule were 1.066 g x cm(-1), 1.013 g x cm(-3) and 98.7%, respectively. And that of long age were 1.026 g x cm(-3), 1.010 g x cm(-3) and 98.4%, respectively. All of them were higher than the long age aerobic granule. The mean diameters of them were 1.9 mm and 2.2 mm, respectively. The settling velocity of short age and long age aerobic granule were 0.005-0.032 m x s(-1) and 0.003-0.028 m x s(-1), respectively, and two kinds of aerobic granule settling velocity increased with the diameter increased. SVI of the former was lower. The COD removal rates of two aerobic granules were above 90%, and the NH4(+) -N removal rates of them were about 85%. The results of the COD effluent concentration, NH4(+) -N effluent concentration and the pollutants concentration in a typical cycle indicated that the short age aerobic granule had better pollutants removal efficiency. The TP removal rates of them were between 40% -90% and 32% -85%, respectively. The TN removal rates of them were about 80%. The SOUR(H) SOUR(NH4) and SOUR(NO2) of the short age aerobic granule were 26.4, 14.8 and 11.2 mg x (h x g)(-1), respectively. And that of long age were 25.2, 14.4 and 8.4 mg x (h x g)(-1), respectively. In summary, the aerobic granule had significantly different physical and chemical characteristics because of different granule age, and the short age aerobic granule exhibited better pollutants removal ability, higher microbial activity and more stability than the long age aerobic granule. PMID:22624385

  18. Microbial desalination cell for enhanced biodegradation of waste engine oil using a novel bacterial strain Bacillus subtilis moh3.

    Science.gov (United States)

    Sabina, K; Fayidh, Mohammed A; Archana, G; Sivarajan, M; Babuskin, S; Babu, P Azhagu Saravana; Radha, K Krishnan; Sukumar, M

    2014-01-01

    Microbial desalination cell (MDC) is a bioelectrochemical system developed recently from microbial fuel cells (MFCs), for producing green energy from organic wastes along with desalination of saltwater. MDC is proved to be a better performer than MFC in terms of power output and chemical oxygen demand removal, with desalination as an additional feature. This study investigates the application potential of MDC for integrated biodegradation of waste engine oil. This study showed, for the first time, that waste engine oil could be used as an organic substrate in MDC, achieving biodegradation of engine oil along with considerable desalination and power production. Utilization of these wastes in MDC can protect the environment from waste engine oil contamination. Indigenous oil-degrading bacteria were isolated and identified from engine oil contaminated sludge. Degradation of waste engine oil by these novel isolates was studied in batch cultures and optimized the growth conditions. The same cultures when used in MDC, gave enhanced biodegradation (70.1 +/- 0.5%) along with desalination (68.3 +/- 0.6%) and power production (3.1 +/- 0.3 mW/m2). Fourier transform-infrared spectroscopy and gas chromatography-mass spectrometry analyses were performed to characterize the degradation metabolites in the anolyte of MDC which clearly indicated the biodegradation of long chain, branched and cyclic hydrocarbons present in waste engine oil. PMID:25145172

  19. Ultrasonically enhanced delivery and degradation of PAHs in a polymer-liquid partitioning system by a microbial consortium.

    Science.gov (United States)

    Isaza, Pedro A; Daugulis, Andrew J

    2009-09-01

    The current study examined the effects of ultrasonic irradiation on mass transfer and degradation of PAHs, by an enriched consortium, when delivered from polymeric matrices. Rates of release into methanol under sonicated conditions, relative to unmixed cases, for phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene were increased approximately fivefold, when delivered from Desmopan 9370 A (polyurethane). Similar effects were observed in Hytrel and Kraton D4150 K polymers as well as recycled Bridgestone tires. Enhancements were also displayed as shifts to higher release equilibria under sonicated conditions, relative to non-sonicated cases, agreeing with current knowledge in sonochemistry and attributed to cavitation. Ultrasonic effects on microbial activity were also investigated and cell damage was found to be non- permanent with consortium re-growth being observed after sonic deactivation. Finally, the lumped effect of sonication on degradation of phenanthrene delivered from Desmopan was examined under the absence and presence of sonication. Rates of degradation were found to be increased by a factor of four demonstrating the possibility of using ultrasonic irradiation for improved mass transport in solid-liquid systems. Cellular inactivation effects were not evident, and this was attributed to the attenuation of sonic energy arising from the presence of solid polymer materials in the medium. The findings of the study demonstrate that sonication can be used to improve mass transport of poorly soluble compounds in microbial degradations, and alleviate limiting steps of soil remediation processes proposed in previous research. PMID:19418561

  20. Graphene/biofilm composites for enhancement of hexavalent chromium reduction and electricity production in a biocathode microbial fuel cell.

    Science.gov (United States)

    Song, Tian-Shun; Jin, Yuejuan; Bao, Jingjing; Kang, Dongzhou; Xie, Jingjing

    2016-11-01

    In this study, a simple method of biocathode fabrication in a Cr(VI)-reducing microbial fuel cell (MFC) is demonstrated. A self-assembling graphene was decorated onto the biocathode microbially, constructing a graphene/biofilm, in situ. The maximum power density of the MFC with a graphene biocathode is 5.7 times that of the MFC with a graphite felt biocathode. Cr(VI) reduction was also enhanced, resulting in 100% removal of Cr(VI) within 48h, at 40mg/L Cr(VI), compared with only 58.3% removal of Cr(VI) in the MFC with a graphite felt biocathode. Cyclic voltammogram analyses showed that the graphene biocathode had faster electron transfer kinetics than the graphite felt version. Energy dispersive spectrometer (EDS) and X-ray photoelectron spectra (XPS) analysis revealed a possible adsorption-reduction mechanism for Cr(VI) reduction via the graphene biocathode. This study attempts to improve the efficiency of the biocathode in the Cr(VI)-reducing MFC, and provides a useful candidate method for the treatment of Cr(VI) contaminated wastewater, under neutral conditions. PMID:27262274

  1. 微生物采油技术的研究进展%DEVELOPMENT OF MICROBIAL ENHANCED OIL RECOVERY RESEARCH

    Institute of Scientific and Technical Information of China (English)

    伍锐东; 黄旭平; 张华军

    2008-01-01

    生物技术特别是微生物采油(Microbial Enhanced Oil Recovery)技术是继热力驱、化学驱、聚合物驱等传统方法之后,利用微生物的有益活动及代谢产物来提高原油采收率的一项综合性技术.与其他三次采油技术相比,MEOR具有工艺简单、费用低、不损伤油层和无污染等优点,是目前最具发展前景的一项提高原油采收率技术.

  2. Strategies for enhancing the effectiveness of metagenomic-based enzyme discovery in lignocellulytic microbial communities

    Energy Technology Data Exchange (ETDEWEB)

    DeAngelis, K.M.; Gladden, J.G.; Allgaier, M.; D' haeseleer, P.; Fortney, J.L.; Reddy, A.; Hugenholtz, P.; Singer, S.W.; Vander Gheynst, J.; Silver, W.L.; Simmons, B.; Hazen, T.C.

    2010-03-01

    Producing cellulosic biofuels from plant material has recently emerged as a key U.S. Department of Energy goal. For this technology to be commercially viable on a large scale, it is critical to make production cost efficient by streamlining both the deconstruction of lignocellulosic biomass and fuel production. Many natural ecosystems efficiently degrade lignocellulosic biomass and harbor enzymes that, when identified, could be used to increase the efficiency of commercial biomass deconstruction. However, ecosystems most likely to yield relevant enzymes, such as tropical rain forest soil in Puerto Rico, are often too complex for enzyme discovery using current metagenomic sequencing technologies. One potential strategy to overcome this problem is to selectively cultivate the microbial communities from these complex ecosystems on biomass under defined conditions, generating less complex biomass-degrading microbial populations. To test this premise, we cultivated microbes from Puerto Rican soil or green waste compost under precisely defined conditions in the presence dried ground switchgrass (Panicum virgatum L.) or lignin, respectively, as the sole carbon source. Phylogenetic profiling of the two feedstock-adapted communities using SSU rRNA gene amplicon pyrosequencing or phylogenetic microarray analysis revealed that the adapted communities were significantly simplified compared to the natural communities from which they were derived. Several members of the lignin-adapted and switchgrass-adapted consortia are related to organisms previously characterized as biomass degraders, while others were from less well-characterized phyla. The decrease in complexity of these communities make them good candidates for metagenomic sequencing and will likely enable the reconstruction of a greater number of full length genes, leading to the discovery of novel lignocellulose-degrading enzymes adapted to feedstocks and conditions of interest.

  3. Dietary nisin modulates the gastrointestinal microbial ecology and enhances growth performance of the broiler chickens.

    Directory of Open Access Journals (Sweden)

    Damian Józefiak

    Full Text Available Due to antimicrobial properties, nisin is one of the most commonly used and investigated bacteriocins for food preservation. Surprisingly, nisin has had limited use in animal feed as well as there are only few reports on its influence on microbial ecology of the gastrointestinal tract (GIT. The present study therefore aimed at investigating effects of dietary nisin on broiler chicken GIT microbial ecology and performance in comparison to salinomycin, the widely used ionophore coccidiostat. In total, 720 one-day-old male Ross 308 chicks were randomly distributed to six experimental groups. The positive control (PC diet was supplemented with salinomycin (60 mg/kg. The nisin (NI diets were supplemented with increasing levels (100, 300, 900 and 2700 IU nisin/g, respectively of the bacteriocin. The negative control (NC diet contained no additives. At slaughter (35 days of age, activity of specific bacterial enzymes (α- and β-glucosidases, α-galactosidases and β-glucuronidase in crop, ileum and caeca were significantly higher (P<0.05 in the NC group, and nisin supplementation decreased the enzyme activities to levels observed for the PC group. A similar inhibitory influence on bacterial activity was reflected in the levels of short-chain fatty acids (SCFA and putrefactive SCFA (PSCFA in digesta from crop and ileum; no effect was observed in caeca. Counts of Bacteroides and Enterobacteriacae in ileum digesta were significantly (P<0.001 decreased by nisin and salinomycin, but no effects were observed on the counts of Clostridium perfringens, Lactobacillus/Enterococcus and total bacteria. Like salinomycin, nisin supplementation improved broiler growth performance in a dose-dependent manner; compared to the NC group, the body weight gain of the NI₉₀₀ and NI₂₇₀₀ groups was improved by 4.7 and 8.7%, respectively. Our findings suggest that dietary nisin exerts a mode of action similar to salinomycin and could be considered as a dietary

  4. Microbially enhanced dissolution and reductive dechlorination of PCE by a mixed culture: Model validation and sensitivity analysis

    Science.gov (United States)

    Chen, Mingjie; Abriola, Linda M.; Amos, Benjamin K.; Suchomel, Eric J.; Pennell, Kurt D.; Löffler, Frank E.; Christ, John A.

    2013-08-01

    Reductive dechlorination catalyzed by organohalide-respiring bacteria is often considered for remediation of non-aqueous phase liquid (NAPL) source zones due to cost savings, ease of implementation, regulatory acceptance, and sustainability. Despite knowledge of the key dechlorinators, an understanding of the processes and factors that control NAPL dissolution rates and detoxification (i.e., ethene formation) is lacking. A recent column study demonstrated a 5-fold cumulative enhancement in tetrachloroethene (PCE) dissolution and ethene formation (Amos et al., 2009). Spatial and temporal monitoring of key geochemical and microbial (i.e., Geobacter lovleyi and Dehalococcoides mccartyi strains) parameters in the column generated a data set used herein as the basis for refinement and testing of a multiphase, compositional transport model. The refined model is capable of simulating the reactive transport of multiple chemical constituents produced and consumed by organohalide-respiring bacteria and accounts for substrate limitations and competitive inhibition. Parameter estimation techniques were used to optimize the values of sensitive microbial kinetic parameters, including maximum utilization rates, biomass yield coefficients, and endogenous decay rates. Comparison and calibration of model simulations with the experimental data demonstrate that the model is able to accurately reproduce measured effluent concentrations, while delineating trends in dechlorinator growth and reductive dechlorination kinetics along the column. Sensitivity analyses performed on the optimized model parameters indicate that the rates of PCE and cis-1,2-dichloroethene (cis-DCE) transformation and Dehalococcoides growth govern bioenhanced dissolution, as long as electron donor (i.e., hydrogen flux) is not limiting. Dissolution enhancements were shown to be independent of cis-DCE accumulation; however, accumulation of cis-DCE, as well as column length and flow rate (i.e., column residence time

  5. Physical injury stimulates aerobic methane emissions from terrestrial plants

    Directory of Open Access Journals (Sweden)

    Z.-P. Wang

    2009-04-01

    Full Text Available Physical injury is common in terrestrial plants as a result of grazing, harvesting, trampling, and extreme weather events. Previous studies demonstrated enhanced emission of non-microbial CH4 under aerobic conditions from plant tissues when they were exposed to increasing UV radiation and temperature. Since physical injury is also a form of environmental stress, we sought to determine whether it would also affect CH4 emissions from plants. Physical injury (cutting stimulated CH4 emission from fresh twigs of Artemisia species under aerobic conditions. More cutting resulted in more CH4 emissions. Hypoxia also enhanced CH4 emission from both uncut and cut Artemisia frigida twigs. Physical injury typically results in cell wall degradation, which may either stimulate formation of reactive oxygen species (ROS or decrease scavenging of them. Increased ROS activity might explain increased CH4 emission in response to physical injury and other forms of stress. There were significant differences in CH4 emissions among 10 species of Artemisia, with some species emitting no detectable CH4 under any circumstances. Consequently, CH4 emissions may be species-dependent and therefore difficult to estimate in nature based on total plant biomass. Our results and those of previous studies suggest that a variety of environmental stresses stimulate CH4 emission from a wide variety of plant species. Global change processes, including climate change, depletion of stratospheric ozone, increasing ground-level ozone, spread of plant pests, and land-use changes, could cause more stress in plants on a global scale, potentially stimulating more CH4 emission globally.

  6. Physical injury stimulates aerobic methane emissions from terrestrial plants

    Directory of Open Access Journals (Sweden)

    Z.-P. Wang

    2009-01-01

    Full Text Available Physical injury is common in terrestrial plants as a result of grazing, trampling, and extreme weather events. Previous studies demonstrated enhanced emission of non-microbial CH4 under aerobic conditions from plant tissues when they were exposed to increasing UV radiation and temperature. Since physical injury is also a form of environmental stress, we sought to determine whether it would also affect CH4 emissions from plants. Physical injury (cutting stimulated CH4 emission from fresh twigs of Artemisiaspecies under aerobic conditions. More cutting resulted in more CH4 emissions. Hypoxia also enhanced CH4 emission from both uncut and cut Artemisia frigida twigs. Physical injury typically results in cell wall degradation, which may either stimulate formation of reactive oxygen species (ROS or decrease scavenging of them. Increased ROS activity might explain increased CH4 emission in response to physical injury and other forms of stress. There were significant differences in CH4 emissions among 10 species of Artemisia, with some species emitting no detectable CH4 under any circumstances. Consequently, CH4 emissions may be species-dependent and therefore difficult to estimate in nature based on total plant biomass. Our results and those of previous studies suggest that a variety environmental stresses stimulate CH4 emission from a wide variety of plant species. Global change processes, including climate change, depletion of stratospheric ozone, increasing ground-level ozone, spread of plant pests, and land-use changes, could cause more stress in plants on a global scale, potentially stimulating more CH4 emission globally.

  7. Dynamic investigation of nutrient consumption and injection strategy in microbial enhanced oil recovery (MEOR) by means of large-scale experiments.

    Science.gov (United States)

    Song, Zhiyong; Zhu, Weiyao; Sun, Gangzheng; Blanckaert, Koen

    2015-08-01

    Microbial enhanced oil recovery (MEOR) depends on the in situ microbial activity to release trapped oil in reservoirs. In practice, undesired consumption is a universal phenomenon but cannot be observed effectively in small-scale physical simulations due to the scale effect. The present paper investigates the dynamics of oil recovery, biomass and nutrient consumption in a series of flooding experiments in a dedicated large-scale sand-pack column. First, control experiments of nutrient transportation with and without microbial consumption were conducted, which characterized the nutrient loss during transportation. Then, a standard microbial flooding experiment was performed recovering additional oil (4.9 % Original Oil in Place, OOIP), during which microbial activity mostly occurred upstream, where oil saturation declined earlier and steeper than downstream in the column. Subsequently, more oil remained downstream due to nutrient shortage. Finally, further research was conducted to enhance the ultimate recovery by optimizing the injection strategy. An extra 3.5 % OOIP was recovered when the nutrients were injected in the middle of the column, and another additional 11.9 % OOIP were recovered by altering the timing of nutrient injection. PMID:25895095

  8. Microbial Degradation of Indole and Its Derivatives

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Arora

    2015-01-01

    Full Text Available Indole and its derivatives, including 3-methylindole and 4-chloroindole, are environmental pollutants that are present worldwide. Microbial degradation of indole and its derivatives can occur in several aerobic and anaerobic pathways; these pathways involve different known and characterized genes. In this minireview, we summarize and explain the microbial degradation of indole, indole-3-acetic acid, 4-chloroindole, and methylindole.

  9. BIOLOGICAL AMENDMENTS AND CROP ROTATIONS FOR MANAGING SOIL MICROBIAL COMMUNITIES AND SOILBORNE DISEASES OF POTATO

    Science.gov (United States)

    Various biological amendments, including commercial biocontrol agents, microbial inoculants, mycorrhizae, and an aerobic compost tea (CT), were evaluated, alone and in conjunction with different crop rotations, for their efficacy in introducing beneficial microorganisms, affecting soil microbial com...

  10. Enhanced method for microbial community DNA extraction and purification from agricultural yellow loess soil.

    Science.gov (United States)

    Kathiravan, Mathur Nadarajan; Gim, Geun Ho; Ryu, Jaewon; Kim, Pyung Il; Lee, Chul Won; Kim, Si Wouk

    2015-11-01

    In this study, novel DNA extraction and purification methods were developed to obtain high-quantity and reliable quality DNA from the microbial community of agricultural yellow loess soil samples. The efficiencies of five different soil DNAextraction protocols were evaluated on the basis of DNA yield, quality and DNA shearing. Our suggested extraction method, which used CTAB, EDTA and cell membrane lytic enzymes in the extraction followed by DNA precipitation using isopropanol, yielded a maximum DNA content of 42.28 ± 5.59 µg/g soil. In addition, among the five different purification protocols, the acid-treated polyvinyl polypyrrolidone (PVPP) spin column purification method yielded high-quality DNA and recovered 91% of DNA from the crude DNA. Spectrophotometry revealed that the ultraviolet A 260/A 230 and A 260/A 280 absorbance ratios of the purified DNA were 1.82 ± 0.03 and 1.94 ± 0.05, respectively. PCR-based 16S rRNA amplification showed clear bands at ~1.5 kb with acid-treated PVPP-purified DNA templates. In conclusion, our suggested extraction and purification protocols can be used to recover high concentration, high purity, and high-molecular-weight DNA from clay and silica-rich agricultural soil samples. PMID:26502961

  11. Biochar Based Microbial Fuel Cell for Enhanced Wastewater Treatment and Nutrient Recovery

    Directory of Open Access Journals (Sweden)

    Tyler M. Huggins

    2016-02-01

    Full Text Available Waste-wood derived biochar was evaluated for the first time as both an anode and cathode material, simultaneously, in an overflow style microbial fuel cell (MFC using actual industrial wastewater. Results show that the average chemical oxygen demand (COD removal was 95% with a reduction rate of 0.53 kg·COD·m−1·d−1 in closed operation mode. The ammonia and phosphorous reductions from wastewater was 73% and 88%, respectively. Stable power production was observed with a peak power density measured at 6 W/m3. Preliminary contributions of physical, biological, and electrochemical COD removals were evaluated, and the results show such combined mechanisms give BC an advantage for MFC applications. Nutrient recovery data showed high levels of macronutrients adsorbed onto the spent biochar electrodes, and phosphorus concentration increased from 0.16 g·kg−1 in raw BC to up to 1.9 g·kg−1 in the cathode. These findings highlight the use of biochar as electrodes in MFCs to facilitate simultaneous wastewater treatment and power production with additional agronomic benefits.

  12. Low doses of imatinib induce myelopoiesis and enhance host anti-microbial immunity.

    Directory of Open Access Journals (Sweden)

    Ruth J Napier

    2015-03-01

    Full Text Available Imatinib mesylate (Gleevec inhibits Abl1, c-Kit, and related protein tyrosine kinases (PTKs and serves as a therapeutic for chronic myelogenous leukemia and gastrointestinal stromal tumors. Imatinib also has efficacy against various pathogens, including pathogenic mycobacteria, where it decreases bacterial load in mice, albeit at doses below those used for treating cancer. We report that imatinib at such low doses unexpectedly induces differentiation of hematopoietic stem cells and progenitors in the bone marrow, augments myelopoiesis but not lymphopoiesis, and increases numbers of myeloid cells in blood and spleen. Whereas progenitor differentiation relies on partial inhibition of c-Kit by imatinib, lineage commitment depends upon inhibition of other PTKs. Thus, imatinib mimics "emergency hematopoiesis," a physiological innate immune response to infection. Increasing neutrophil numbers by adoptive transfer sufficed to reduce mycobacterial load, and imatinib reduced bacterial load of Franciscella spp., which do not utilize imatinib-sensitive PTKs for pathogenesis. Thus, potentiation of the immune response by imatinib at low doses may facilitate clearance of diverse microbial pathogens.

  13. Power Generation Enhancement by Utilizing Plant Photosynthate in Microbial Fuel Cell Coupled Constructed Wetland System

    Directory of Open Access Journals (Sweden)

    Shentan Liu

    2013-01-01

    Full Text Available In the present study, a new technology that coupled constructed wetland (CW with microbial fuel cell (MFC (CW-MFC was developed to convert solar energy into electricity on the principles of photosynthetic MFC by utilizing root exudates of Ipomoea aquatica as part of fuel. The maximum power density of 12.42 mW m−2 produced from the CW-MFC planted with Ipomoea aquatica was 142% higher than that of 5.13 mW m−2 obtained from the unplanted CW-MFC. The maximum power output for the planted CW-MFC could be divided into two parts: the maximum power yield from in the water body was 66.05 KJ Kg−1  , and the maximum power transformation from plant photosynthesis was 2.31 GJ ha−1 year−1. The average COD removal efficiencies were 92.1% and 94.8% in the unplanted CW-MFC and planted CW-MFC, respectively; the average TN removal efficiencies amounted to 54.4% and 90.8% in the unplanted CW-MFC and planted CW-MFC. This research demonstrates that planting Ipomoea aquatica in the CW-MFC achieved a higher power density and nutrient removal of nitrogen simultaneously.

  14. Enhanced hydrogen generation using a saline catholyte in a two chamber microbial electrolysis cell

    KAUST Repository

    Nam, Joo-Youn

    2011-11-01

    High rates of hydrogen gas production were achieved in a two chamber microbial electrolysis cell (MEC) without a catholyte phosphate buffer by using a saline catholyte solution and a cathode constructed around a stainless steel mesh current collector. Using the non-buffered salt solution (68 mM NaCl) produced the highest current density of 131 ± 12 A/m3, hydrogen yield of 3.2 ± 0.3 mol H2/mol acetate, and gas production rate of 1.6 ± 0.2 m3 H2/m 3·d, compared to MECs with catholytes externally sparged with CO2 or containing a phosphate buffer. The salinity of the catholyte achieved a high solution conductivity, and therefore the electrode spacing did not appreciably affect performance. The coulombic efficiency with the cathode placed near the membrane separating the chambers was 83 ± 4%, similar to that obtained with the cathode placed more distant from the membrane (84 ± 4%). Using a carbon cloth cathode instead of the stainless steel mesh cathode did not significantly affect performance, with all reactor configurations producing similar performance in terms of total gas volume, COD removal, rcat and overall energy recovery. These results show MEC performance can be improved by using a saline catholyte without pH control. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  15. Adaptive microbial population shifts in response to a continuous ethanol blend release increases biodegradation potential

    International Nuclear Information System (INIS)

    The fate of fuel releases largely depends on the poorly-understood response in microbial community structure and function. Here, we evaluate the impacts to the microbial community resulting from a pilot-scale continuous release (10 months) of a 10% v:v ethanol solution mixed with benzene and toluene (50 mg/L each). Microbial population shifts were characterized by pyrosequencing-based 16S rRNA analysis and by quantitative PCR targeting Bacteria, Archaea, and functional genes for methanogenesis (mcrA), acetogenesis (fhs) and aerobic degradation of aromatic hydrocarbons (PHE), which could occur in hypoxic micro-environments. The release stimulated microbial growth, increased species richness and diversity, and selected for genotypes involved in fermentative degradation (the relative abundance of mcrA and fhs increased 18- and 6-fold, respectively). The growth of putative hydrocarbon degraders and commensal anaerobes, and increases in microbial diversity and in degradation rates suggest an adaptive response that increases the potential for natural attenuation of ethanol blend releases. -- Highlights: •Pyrosequencing discerned microbial community changes after an ethanol blend release. •Adaptive microbial population shifts that enhance bioremediation were observed. •Hydrocarbon degraders and fermentation syntrophs proliferated. •Surprisingly, both species richness and taxonomic diversity increased. -- Pyrosequencing analysis discerned adaptive microbial population shifts that increase natural attenuation potential of an ethanol-blended fuel release

  16. Bacterial Community Analysis, New Exoelectrogen Isolation and Enhanced Performance of Microbial Electrochemical Systems Using Nano-Decorated Anodes

    Science.gov (United States)

    Xu, Shoutao

    . Citrobacter strain SX-1 is capable of generating electricity from a wide range of substrates in MFCs. This finding increases the known diversity of power generating exoelectrogens and provids a new strain to explore the mechanisms of extracellular electron transfer from bacteria to electrode. The wide range of substrate utilization by SX-1 increases the application potential of MFCs in renewable energy generation and waste treatment. Anode properties are critical for the performance of microbial electrolysis cells (MECs). Inexpensive Fe nanoparticle modified graphite disks were used as anodes to preliminarily investigate the effects of nanoparticles on the performance of Shewanella oneidensis MR-1 in MECs. Results demonstrated that average current densities produced with Fe nanoparticle decorated anodes were up to 5.9-fold higher than plain graphite anodes. Whole genome microarray analysis of the gene expression showed that genes encoding biofilm formation were significantly up-regulated as a response to nanoparticle decorated anodes. Increased expression of genes related to nanowires, flavins and c-type cytochromes indicate that enhanced mechanisms of electron transfer to the anode may also have contributed to the observed increases in current density. The majority of the remaining differentially expressed genes were associated with electron transport and anaerobic metabolism demonstrating a systemic response to increased power loads. The carbon nanotube (CNT) is another form of nano materials. Carbon nanotube (CNT) modified graphite disks were used as anodes to investigate the effects of nanostructures on the performance S. oneidensis MR-1 in microbial electrolysis cells (MECs). The current densities produced with CNT decorated anodes were up to 5.6-fold higher than plain graphite anodes. Global transcriptome analysis showed that cytochrome c genes associated with extracellular electron transfer are up-expressed by CNT decorated anodes, which is the leading factor to

  17. Reducing the activity and secretion of microbial antioxidants enhances the immunogenicity of BCG.

    Directory of Open Access Journals (Sweden)

    Shanmugalakshmi Sadagopal

    Full Text Available BACKGROUND: In early clinical studies, the live tuberculosis vaccine Mycobacterium bovis BCG exhibited 80% protective efficacy against pulmonary tuberculosis (TB. Although BCG still exhibits reliable protection against TB meningitis and miliary TB in early childhood it has become less reliable in protecting against pulmonary TB. During decades of in vitro cultivation BCG not only lost some genes due to deletions of regions of the chromosome but also underwent gene duplication and other mutations resulting in increased antioxidant production. METHODOLOGY/PRINCIPAL FINDINGS: To determine whether microbial antioxidants influence vaccine immunogenicity, we eliminated duplicated alleles encoding the oxidative stress sigma factor SigH in BCG Tice and reduced the activity and secretion of iron co-factored superoxide dismutase. We then used assays of gene expression and flow cytometry with intracellular cytokine staining to compare BCG-specific immune responses in mice after vaccination with BCG Tice or the modified BCG vaccine. Compared to BCG, the modified vaccine induced greater IL-12p40, RANTES, and IL-21 mRNA in the spleens of mice at three days post-immunization, more cytokine-producing CD8+ lymphocytes at the peak of the primary immune response, and more IL-2-producing CD4+ lymphocytes during the memory phase. The modified vaccine also induced stronger secondary CD4+ lymphocyte responses and greater clearance of challenge bacilli. CONCLUSIONS/SIGNIFICANCE: We conclude that antioxidants produced by BCG suppress host immune responses. These findings challenge the hypothesis that the failure of extensively cultivated BCG vaccines to prevent pulmonary tuberculosis is due to over-attenuation and suggest instead a new model in which BCG evolved to produce more immunity-suppressing antioxidants. By targeting these antioxidants it may be possible to restore BCG's ability to protect against pulmonary TB.

  18. An automated workflow for enhancing microbial bioprocess optimization on a novel microbioreactor platform

    Directory of Open Access Journals (Sweden)

    Rohe Peter

    2012-10-01

    Full Text Available Abstract Background High-throughput methods are widely-used for strain screening effectively resulting in binary information regarding high or low productivity. Nevertheless achieving quantitative and scalable parameters for fast bioprocess development is much more challenging, especially for heterologous protein production. Here, the nature of the foreign protein makes it impossible to predict the, e.g. best expression construct, secretion signal peptide, inductor concentration, induction time, temperature and substrate feed rate in fed-batch operation to name only a few. Therefore, a high number of systematic experiments are necessary to elucidate the best conditions for heterologous expression of each new protein of interest. Results To increase the throughput in bioprocess development, we used a microtiter plate based cultivation system (Biolector which was fully integrated into a liquid-handling platform enclosed in laminar airflow housing. This automated cultivation platform was used for optimization of the secretory production of a cutinase from Fusarium solani pisi with Corynebacterium glutamicum. The online monitoring of biomass, dissolved oxygen and pH in each of the microtiter plate wells enables to trigger sampling or dosing events with the pipetting robot used for a reliable selection of best performing cutinase producers. In addition to this, further automated methods like media optimization and induction profiling were developed and validated. All biological and bioprocess parameters were exclusively optimized at microtiter plate scale and showed perfect scalable results to 1 L and 20 L stirred tank bioreactor scale. Conclusions The optimization of heterologous protein expression in microbial systems currently requires extensive testing of biological and bioprocess engineering parameters. This can be efficiently boosted by using a microtiter plate cultivation setup embedded into a liquid-handling system, providing more throughput

  19. Aerobic biotransformation of polyfluoroalkyl phosphate esters (PAPs) in soil.

    Science.gov (United States)

    Liu, Chen; Liu, Jinxia

    2016-05-01

    Microbial transformation of polyfluoroalkyl phosphate esters (PAPs) into perfluorocarboxylic acids (PFCAs) has recently been confirmed to occur in activated sludge and soil. However, there lacks quantitative information about the half-lives of the PAPs and their significance as the precursors to PFCAs. In the present study, the biotransformation of 6:2 and 8:2 diPAP in aerobic soil was investigated in semi-dynamics reactors using improved sample preparation methods. To develop an efficient extraction method for PAPs, six different extraction solvents were compared, and the phenomenon of solvent-enhanced hydrolysis was investigated. It was found that adding acetic acid could enhance the recoveries of the diPAPs and inhibit undesirable hydrolysis during solvent extraction of soil. However 6:2 and 8:2 monoPAPs, which are the first breakdown products from diPAPs, were found to be unstable in the six solvents tested and quickly hydrolyzed to form fluorotelomer alcohols. Therefore reliable measurement of the monoPAPs from a live soil was not achievable. The apparent DT50 values of 6:2 diPAP and 8:2 diPAP biotransformation were estimated to be 12 and > 1000 days, respectively, using a double first-order in parallel model. At the end of incubation of day 112, the major degradation products of 6:2 diPAP were 5:3 fluorotelomer carboxylic acid (5:3 acid, 9.3% by mole), perfluoropentanoic acid (PFPeA, 6.4%) and perfluorohexanoic acid (PFHxA, 6.0%). The primary product of 8:2 diPAP was perfluorooctanoic acid (PFOA, 2.1%). The approximately linear relationship between the half-lives of eleven polyfluoroalkyl and perfluoroalkyl substances (PFASs, including 6:2 and 8:2 diPAPs) that biotransform in aerobic soils and their molecular weights suggested that the molecular weight is a good indicator of the general stability of low-molecular-weight PFAS-based compounds in aerobic soils. PMID:26849529

  20. A metagenome of a full-scale microbial community carrying out enhanced biological phosphorus removal

    OpenAIRE

    Albertsen, Mads; Hansen, Lea Benedicte Skov; Saunders, Aaron Marc; Nielsen, Per Halkjær; Nielsen, Kåre Lehmann

    2011-01-01

    Enhanced biological phosphorus removal (EBPR) is widely used for removal of phosphorus from wastewater. In this study, a metagenome (18.2 Gb) was generated using Illumina sequencing from a full-scale EBPR plant to study the community structure and genetic potential. Quantitative fluorescence in situ hybridization (qFISH) was applied as an independent method to evaluate the community structure. The results were in qualitative agreement, but a DNA extraction bias against gram positive bacteria ...

  1. Integrative microbial community analysis reveals full-scale enhanced biological phosphorus removal under tropical conditions

    OpenAIRE

    Yingyu Law; Rasmus Hansen Kirkegaard; Angel Anisa Cokro; Xianghui Liu; Krithika Arumugam; Chao Xie; Mikkel Stokholm-Bjerregaard; Drautz-Moses, Daniela I.; Per Halkjær Nielsen; Stefan Wuertz; Rohan B. H. Williams

    2016-01-01

    Management of phosphorus discharge from human waste is essential for the control of eutrophication in surface waters. Enhanced biological phosphorus removal (EBPR) is a sustainable, efficient way of removing phosphorus from waste water without employing chemical precipitation, but is assumed unachievable in tropical temperatures due to conditions that favour glycogen accumulating organisms (GAOs) over polyphosphate accumulating organisms (PAOs). Here, we show these assumptions are unfounded b...

  2. The spherical nanoparticle-encapsulated chlorhexidine enhances anti-biofilm efficiency through an effective releasing mode and close microbial interactions

    Science.gov (United States)

    Li, Xuan; Wong, Chi-Hin; Ng, Tsz-Wing; Zhang, Cheng-Fei; Leung, Ken Cham-Fai; Jin, Lijian

    2016-01-01

    We reported two forms (sphere and wire) of newly fabricated chlorhexidine (CHX)-loaded mesoporous silica nanoparticles (MSNs), and investigated their releasing capacities and anti-biofilm efficiencies. The interactions of the blank MSNs with planktonic oral microorganisms were assessed by field emission scanning electron microscopy. The anti-biofilm effects of the two forms of nanoparticle-encapsulated CHX were examined by 2,3-bis (2-methoxy- 4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide. The profiles of biofilm penetration were analyzed by fluorescent-labeled MSNs using confocal microscopy and ImageJ. The spherical MSNs with an average diameter of 265 nm exhibited a larger surface area and faster CHX-releasing rate than the MSN wires. The field emission scanning electron microscopy images showed that both shaped MSNs enabled to attach and further fuse with the surfaces of testing microbes. Meanwhile, the nanoparticle-encapsulated CHX could enhance the anti-biofilm efficiency with reference to its free form. Notably, the spherical nanoparticle-encapsulated CHX presented with a greater anti-biofilm capacity than the wire nanoparticle-encapsulated CHX, partly due to their difference in physical property. Furthermore, the relatively even distribution and homogeneous dispersion of spherical MSNs observed in confocal images may account for the enhanced penetration of spherical nanoparticle-encapsulated CHX into the microbial biofilms and resultant anti-biofilm effects. These findings reveal that the spherical nanoparticle-encapsulated CHX could preferably enhance its anti-biofilm efficiency through an effective releasing mode and close interactions with microbes. PMID:27330290

  3. Molecular Analysis of Bacterial Community DNA in Sludge Undergoing Autothermal Thermophilic Aerobic Digestion (ATAD: Pitfalls and Improved Methodology to Enhance Diversity Recovery

    Directory of Open Access Journals (Sweden)

    Anna V. Piterina

    2010-03-01

    Full Text Available Molecular analysis of the bacterial community structure associated with sludge processed by autothermal thermophilic aerobic digestion (ATAD, was performed using a number of extraction and amplification procedures which differed in yield, integrity, ability to amplify extracted templates and specificity in recovering species present. Interference to PCR and qPCR amplification was observed due to chelation, nuclease activity and the presence of thermolabile components derived from the ATAD sludge. Addition of selected adjuvant restored the ability to amplify community DNA, derived from the thermophilic sludge, via a number of primer sets of ecological importance and various DNA polymerases. Resolution of community profiles by molecular techniques was also influenced by the ATAD sludge extraction procedure as demonstrated by PCR-DGGE profiling and comparison of taxonomic affiliations of the most predominant members within 16S rRNA gene libraries constructed from ATAD DNA extracted by different methods. Several modifications have been shown to be necessary to optimize the molecular analysis of the ATAD thermal niche which may have general applicability to diversity recovery from similar environments.

  4. Performance of biological phosphorus removal and characteristics of microbial community in the oxic-settling-anaerobic process by FISH analysis

    Institute of Scientific and Technical Information of China (English)

    Jian-fang WANG; Qing-liang ZHAO; Wen-biao JIN; Shi-jie YOU; Jin-na ZHANG

    2008-01-01

    Performance of biological phosphorus removal in the oxic-settling-anaerobic (OSA) process was investigated. Cell staining and fluorescent in situ hybridization (FISH) were used to analyze characteristics and microbial community of sludge.Experimental results showed that phosphorus removal efficiency was near 60% and the amount of biological phosphorus accumulation in aerobic sludge of the OSA system was up to 26.9 mg/g. Biological phosphorus removal efficiency was partially inhibited by carbon sources in the continuous OSA system. Contrasted to the OSA system, biological phosphorus removal efficiency was enhanced by 14% and the average total phosphorus (TP) contents of aerobic sludge were increased by 0.36 mg/g when sufficient carbon sources were supplied in batch experiments. Staining methods indicated that about 35% of microorganisms had typical characteristics of phosphorus accumulating organisms (PAOs). FISH analysis demonstrated that PAOMIX-binding bacteria were predominant microbial communities in the OSA system, which accounted for around 28% of total bacteria.

  5. Enhancement of Copper Availability and Microbial Community Changes in Rice Rhizospheres Affected by Sulfur

    Directory of Open Access Journals (Sweden)

    Xiao-Feng Yuan

    2011-02-01

    Full Text Available The role of sulfur on the availability of Cu and the bacterial community in rice rhizospheres was investigated by pot experiments. With sulfur addition, pH in rhizosphere soil decreased and Mg(NO32 extractable Cu increased significantly. The bacterial community composition also changed with sulfur addition. Some specific clones having high similarity to Thiobacillus, which indicated that sulfur oxidation in the rice rhizosphere could increase the availability of Cu. These results suggested that sulfur source which could provide substrate to sulfur oxidizing bacteria and enhance the availability of Cu was not a suitable sulfur fertilizer for Cu polluted soil.

  6. Aerobic Anoxygenic Phototrophic Bacteria

    OpenAIRE

    Yurkov, Vladimir V.; Beatty, J. Thomas

    1998-01-01

    The aerobic anoxygenic phototrophic bacteria are a relatively recently discovered bacterial group. Although taxonomically and phylogenetically heterogeneous, these bacteria share the following distinguishing features: the presence of bacteriochlorophyll a incorporated into reaction center and light-harvesting complexes, low levels of the photosynthetic unit in cells, an abundance of carotenoids, a strong inhibition by light of bacteriochlorophyll synthesis, and the inability to grow photosynt...

  7. Aerobic Degradation of N-Methyl-4-Nitroaniline (MNA) by Pseudomonas sp. Strain FK357 Isolated from Soil

    OpenAIRE

    Khan, Fazlurrahman; Vyas, Bhawna; Pal, Deepika; Cameotra, Swaranjit Singh

    2013-01-01

    N-Methyl-4-nitroaniline (MNA) is used as an additive to lower the melting temperature of energetic materials in the synthesis of insensitive explosives. Although the biotransformation of MNA under anaerobic condition has been reported, its aerobic microbial degradation has not been documented yet. A soil microcosms study showed the efficient aerobic degradation of MNA by the inhabitant soil microorganisms. An aerobic bacterium, Pseudomonas sp. strain FK357, able to utilize MNA as the sole car...

  8. A metagenome of a full-scale microbial community carrying out Enhanced Biological Phosphorus Removal

    DEFF Research Database (Denmark)

    Albertsen, Mads; Hansen, Lea Benedicte Skov; Saunders, Aaron Marc;

    2012-01-01

    Enhanced biological phosphorus removal (EBPR) is widely used for removal of phosphorus from wastewater. In this study, a metagenome (18.2 Gb) was generated using Illumina sequencing from a full-scale EBPR plant to study the community structure and genetic potential. Quantitative fluorescence...... the use of qFISH. The genetic potential for community function showed enrichment of genes involved in phosphate metabolism and biofilm formation, reflecting the selective pressure of the EBPR process. Most contigs in the assembled metagenome had low similarity to genes from currently sequenced genomes......, underlining the need for more reference genomes of key EBPR species. Only the genome of ‘Candidatus Accumulibacter’, a genus of phosphorus-removing organisms, was closely enough related to the species present in the metagenome to allow for detailed investigations. Accumulibacter accounted for only 4.8% of all...

  9. Fundamental studies for microbial enhanced oil recovery field test; Biseibutsu koho (MEOR) fuirudo tesuto no tameno kisoteki kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Enomoto, H. [Tohoku Univ., Sendai (Japan). Dept. of Geoscience and Tech.; Fujiwara, K. [Kansai Research Inst., Kyoto (Japan). Lefescience Research Center; Yonebayashi, H. [Japan National Oil Corp., Tokyo (Japan). Tech. Research Center

    2000-03-01

    This paper describes a series of experiments relevant to the screening of microbes to adapt and monitor the targeted microbes in the microbial enhanced oil recovery (MEOR) process. Firstly, the samples of reservoir brine, soil of well site, drilling cuttings, and activated sludge were collected from domestic oil fields, drilling sites, sewage treatment facilities, and environmental conditions. To achieve higher oil recovery, metabolic products of isolates were individually evaluated. These isolates were also incubated in culture bottles packed with silica sands, to clarify the growth potential and metabolic activity in the micro culture space. By carrying out two stages of flooding experiments simulating the reservoir environment, the capability of isolates for improving oil recovery was evaluated, and the microbes were selected. Two gene-engineering techniques were established in parallel with the screening experiments for monitoring the microbes injected into the reservoir. These techniques are potentially capable of rapidly detecting the presence of injecting microbes; moreover, they are available and effective for studying the microbes relevant to the MEOR process. In addition, it was demonstrated that metabolic activity of the microbes capable of producing effective gas could be estimated based on the quantity of 2,3-butanediol found as a major end product of fermentation. The results of the huff and puff field test implied that the gene-engineering techniques established in this study and the metabolic activity analysis on 2,3-butanediol were effective for understanding the growth and metabolic activity of the microbes injected into the reservoir. (author)

  10. Venezuela-MEM/USA-DOE Fossil Energy Report XIII-1, Supporting Technology for Enhanced Oil Recovery, Microbial EOR

    Energy Technology Data Exchange (ETDEWEB)

    Ziritt, Jose Luis

    1999-11-03

    The results from Annex XIII of the Cooperative Agreement between the United States Department of Energy (DOE) and the Ministry of Energy and Mines of the Republic of Venezuela (MEMV) have been documented and published with many researchers involved. Integrate comprehensive research programs in the area of Microbial Enhanced Oil Recovery (MEOR) ranged from feasibility laboratory studies to full-scale multi-well field pilots. The objective, to cooperate in a technical exchange of ideas and information was fully met throughout the life of the Annex. Information has been exchanged between the two countries through published reports and technical meetings between experts in both country's research communities. The meetings occurred every two years in locations coincident with the International MEOR conferences & workshops sponsored by DOE (June 1990, University of Oklahoma, September 1992, Brookhaven, September 1995, National Institute of Petroleum and Energy Research). Reports and publications produced during these years are listed in Appendix B. Several Annex managers have guided the exchange through the years. They included Luis Vierma, Jose Luis Zirritt, representing MEMV and E. B. Nuckols, Edith Allison, and Rhonda Lindsey, representing the U.S. DOE. Funding for this area of research remained steady for a few years but decreased in recent years. Because both countries have reduced research programs in this area, future exchanges on this topic will occur through ANNEX XV. Informal networks established between researchers through the years should continue to function between individuals in the two countries.

  11. Bacillus amyloliquefaciens TSBSO 3.8, a biosurfactant-producing strain with biotechnological potential for microbial enhanced oil recovery.

    Science.gov (United States)

    Alvarez, Vanessa Marques; Jurelevicius, Diogo; Marques, Joana Montezano; de Souza, Pamella Macedo; de Araújo, Livia Vieira; Barros, Thalita Gonçalves; de Souza, Rodrigo Octavio Mendonça Alves; Freire, Denise Maria Guimarães; Seldin, Lucy

    2015-12-01

    A screening for biosurfactant-producing bacteria was conducted with 217 strains that were isolated from environmental samples contaminated with crude oil and/or petroleum derivatives. Although 19 promising biosurfactant producers were detected, strain TSBSO 3.8, which was identified by molecular methods as Bacillus amyloliquefaciens, drew attention for its production of a high-activity compound that presented an emulsification activity of 63% and considerably decreased surface (28.5 mN/m) and interfacial (11.4 mN/m) tensions in Trypticase Soy Broth culture medium. TSBSO 3.8 growth and biosurfactant production were tested under different physical and chemical conditions to evaluate its biotechnological potential. Biosurfactant production occurred between 0.5% and 7% NaCl, at pH values varying from 6 to 9 and temperatures ranging from 28 to 50 °C. Moreover, biosurfactant properties remained the same after autoclaving at 121 °C for 15 min. The biosurfactant was also successful in a test to simulate microbial enhanced oil recovery (MEOR). Mass spectrometry analysis showed that the surface active compound was a surfactin, known as a powerful biosurfactant that is commonly produced by Bacillus species. The production of a high-efficiency biosurfactant, under some physical and chemical conditions that resemble those experienced in an oil production reservoir, such as high salinities and temperatures, makes TSBSO 3.8 an excellent candidate and creates good expectations for its application in MEOR. PMID:26350801

  12. Microbially Enhanced Oil Recovery by Sequential Injection of Light Hydrocarbon and Nitrate in Low- And High-Pressure Bioreactors.

    Science.gov (United States)

    Gassara, Fatma; Suri, Navreet; Stanislav, Paul; Voordouw, Gerrit

    2015-10-20

    Microbially enhanced oil recovery (MEOR) often involves injection of aqueous molasses and nitrate to stimulate resident or introduced bacteria. Use of light oil components like toluene, as electron donor for nitrate-reducing bacteria (NRB), offers advantages but at 1-2 mM toluene is limiting in many heavy oils. Because addition of toluene to the oil increased reduction of nitrate by NRB, we propose an MEOR technology, in which water amended with light hydrocarbon below the solubility limit (5.6 mM for toluene) is injected to improve the nitrate reduction capacity of the oil along the water flow path, followed by injection of nitrate, other nutrients (e.g., phosphate) and a consortium of NRB, if necessary. Hydrocarbon- and nitrate-mediated MEOR was tested in low- and high-pressure, water-wet sandpack bioreactors with 0.5 pore volumes of residual oil in place (ROIP). Compared to control bioreactors, those with 11-12 mM of toluene in the oil (gained by direct addition or by aqueous injection) and 80 mM of nitrate in the aqueous phase produced 16.5 ± 4.4% of additional ROIP (N = 10). Because toluene is a cheap commodity chemical, HN-MEOR has the potential to be a cost-effective method for additional oil production even in the current low oil price environment. PMID:26406569

  13. Venezuela-MEM/USA-DOE Fossil Energy Report XIII-1, Supporting Technology for Enhanced Oil Recovery, Microbial EOR; FINAL

    International Nuclear Information System (INIS)

    The results from Annex XIII of the Cooperative Agreement between the United States Department of Energy (DOE) and the Ministry of Energy and Mines of the Republic of Venezuela (MEMV) have been documented and published with many researchers involved. Integrate comprehensive research programs in the area of Microbial Enhanced Oil Recovery (MEOR) ranged from feasibility laboratory studies to full-scale multi-well field pilots. The objective, to cooperate in a technical exchange of ideas and information was fully met throughout the life of the Annex. Information has been exchanged between the two countries through published reports and technical meetings between experts in both country's research communities. The meetings occurred every two years in locations coincident with the International MEOR conferences and workshops sponsored by DOE (June 1990, University of Oklahoma, September 1992, Brookhaven, September 1995, National Institute of Petroleum and Energy Research). Reports and publications produced during these years are listed in Appendix B. Several Annex managers have guided the exchange through the years. They included Luis Vierma, Jose Luis Zirritt, representing MEMV and E. B. Nuckols, Edith Allison, and Rhonda Lindsey, representing the U.S. DOE. Funding for this area of research remained steady for a few years but decreased in recent years. Because both countries have reduced research programs in this area, future exchanges on this topic will occur through ANNEX XV. Informal networks established between researchers through the years should continue to function between individuals in the two countries

  14. Microbial enhanced heavy oil recovery by the aid of inhabitant spore-forming bacteria: an insight review.

    Science.gov (United States)

    Shibulal, Biji; Al-Bahry, Saif N; Al-Wahaibi, Yahya M; Elshafie, Abdulkader E; Al-Bemani, Ali S; Joshi, Sanket J

    2014-01-01

    Crude oil is the major source of energy worldwide being exploited as a source of economy, including Oman. As the price of crude oil increases and crude oil reserves collapse, exploitation of oil resources in mature reservoirs is essential for meeting future energy demands. As conventional recovery methods currently used have become less efficient for the needs, there is a continuous demand of developing a new technology which helps in the upgradation of heavy crude oil. Microbial enhanced oil recovery (MEOR) is an important tertiary oil recovery method which is cost-effective and eco-friendly technology to drive the residual oil trapped in the reservoirs. The potential of microorganisms to degrade heavy crude oil to reduce viscosity is considered to be very effective in MEOR. Earlier studies of MEOR (1950s) were based on three broad areas: injection, dispersion, and propagation of microorganisms in petroleum reservoirs; selective degradation of oil components to improve flow characteristics; and production of metabolites by microorganisms and their effects. Since thermophilic spore-forming bacteria can thrive in very extreme conditions in oil reservoirs, they are the most suitable organisms for the purpose. This paper contains the review of work done with thermophilic spore-forming bacteria by different researchers. PMID:24550702

  15. Microbial Enhanced Heavy Oil Recovery by the Aid of Inhabitant Spore-Forming Bacteria: An Insight Review

    Directory of Open Access Journals (Sweden)

    Biji Shibulal

    2014-01-01

    Full Text Available Crude oil is the major source of energy worldwide being exploited as a source of economy, including Oman. As the price of crude oil increases and crude oil reserves collapse, exploitation of oil resources in mature reservoirs is essential for meeting future energy demands. As conventional recovery methods currently used have become less efficient for the needs, there is a continuous demand of developing a new technology which helps in the upgradation of heavy crude oil. Microbial enhanced oil recovery (MEOR is an important tertiary oil recovery method which is cost-effective and eco-friendly technology to drive the residual oil trapped in the reservoirs. The potential of microorganisms to degrade heavy crude oil to reduce viscosity is considered to be very effective in MEOR. Earlier studies of MEOR (1950s were based on three broad areas: injection, dispersion, and propagation of microorganisms in petroleum reservoirs; selective degradation of oil components to improve flow characteristics; and production of metabolites by microorganisms and their effects. Since thermophilic spore-forming bacteria can thrive in very extreme conditions in oil reservoirs, they are the most suitable organisms for the purpose. This paper contains the review of work done with thermophilic spore-forming bacteria by different researchers.

  16. Bifunctional Manganese Ferrite/Polyaniline Hybrid as Electrode Material for Enhanced Energy Recovery in Microbial Fuel Cell.

    Science.gov (United States)

    Khilari, Santimoy; Pandit, Soumya; Varanasi, Jhansi L; Das, Debabrata; Pradhan, Debabrata

    2015-09-23

    Microbial fuel cells (MFCs) are emerging as a sustainable technology for waste to energy conversion where electrode materials play a vital role on its performance. Platinum (Pt) is the most common material used as cathode catalyst in the MFCs. However, the high cost and low earth abundance associated with Pt prompt the researcher to explore inexpensive catalysts. The present study demonstrates a noble metal-free MFC using a manganese ferrite (MnFe2O4)/polyaniline (PANI)-based electrode material. The MnFe2O4 nanoparticles (NPs) and MnFe2O4 NPs/PANI hybrid composite not only exhibited superior oxygen reduction reaction (ORR) activity for the air cathode but also enhanced anode half-cell potential upon modifying carbon cloth anode in the single-chambered MFC. This is attributed to the improved extracellular electron transfer of exoelectrogens due to Fe(3+) in MnFe2O4 and its capacitive nature. The present work demonstrates for the first time the dual property of MnFe2O4 NPs/PANI, i.e., as cathode catalyst and an anode modifier, thereby promising cost-effective MFCs for practical applications. PMID:26315619

  17. Enhanced hydrogen production in microbial electrolysis cell with 3D self-assembly nickel foam-graphene cathode.

    Science.gov (United States)

    Cai, Weiwei; Liu, Wenzong; Han, Jinglong; Wang, Aijie

    2016-06-15

    In comparison to precious metal catalyst especially Platinum (Pt), nickel foam (NF) owned cheap cost and unique three-dimensional (3D) structure, however, it was scarcely applied as cathode material in microbial electrolysis cell (MEC) as the intrinsic laggard electrochemical activity for hydrogen recovery. In this study, a self-assembly 3D nickel foam-graphene (NF-G) cathode was fabricated by facile hydrothermal approach for hydrogen evolution in MECs. Electrochemical analysis (linear scan voltammetry and electrochemical impedance spectroscopy) revealed the improved electrochemical activity and effective mass diffusion after coating with graphene. NF-G as cathode in MEC showed a significant enhancement in hydrogen production rate compared with nickel foam at a variety of biases. Noticeably, NF-G showed a comparable averaged hydrogen production rate (1.31±0.07mL H2mL(-1) reactord(-1)) to Platinum/carbon (Pt/C) (1.32±0.07mL H2mL(-1) reactord(-1)) at 0.8V. Profitable energy recovery could be achieved by NF-G cathode at higher applied voltage, which performed the best hydrogen yield of 3.27±0.16mol H2mol(-1) acetate at 0.8V and highest energy efficiency of 185.92±6.48% at 0.6V. PMID:26807526

  18. Electrochemically exfoliated graphene anodes with enhanced biocurrent production in single-chamber air-breathing microbial fuel cells.

    Science.gov (United States)

    Najafabadi, Amin Taheri; Ng, Norvin; Gyenge, Előd

    2016-07-15

    Microbial fuel cells (MFCs) present promising options for environmentally sustainable power generation especially in conjunction with waste water treatment. However, major challenges remain including low power density, difficult scale-up, and durability of the cell components. This study reports enhanced biocurrent production in a membrane-free MFC, using graphene microsheets (GNs) as anode and MnOx catalyzed air cathode. The GNs are produced by ionic liquid assisted simultaneous anodic and cathodic electrochemical exfoliation of iso-molded graphite electrodes. The GNs produced by anodic exfoliation increase the MFC peak power density by over 300% compared to plain carbon cloth (i.e., 2.85Wm(-2) vs 0.66Wm(-2), respectively), and by 90% compared to conventional carbon black (i.e., Vulcan XC-72) anode. These results exceed previously reported power densities for graphene-containing MFC anodes. The fuel cell polarization results are corroborated by electrochemical impedance spectroscopy indicating three times lower charge transfer resistance for the GN anode. Material characterizations suggest that the best performing GN samples were of relatively smaller size (~500nm), with higher levels of ionic liquid induced surface functionalization during the electrochemical exfoliation process. PMID:26926591

  19. Microbial transformation of uranium in wastes

    International Nuclear Information System (INIS)

    Contamination of soils, water, and sediments by radionuclides and toxic metals from the disposal of uranium processing wastes is a major national concern. Although much is known about the physico- chemical aspects of U, we have little information on the effects of aerobic and anaerobic microbial activities on the mobilization or immobilization of U and other toxic metals in mixed wastes. In order to understand the mechanisms of microbial transformations of uranium, we examined a contaminated pond sediment and a sludge sample from the uranium processing facility at Y-12 Plant, Oak Ridge, TN. The uranium concentration in the sediment and sludge samples was 923 and 3080 ug/g dry wt, respectively. In addition to U, the sediment and sludge samples contained high levels of toxic metals such as Cd, Cr, Cu, Hg, Pb, Ni, and Zn. The association of uranium with the various mineral fractions of the sediment and sludge was determined by selective chemical extraction techniques. Uranium was associated to varying degrees with the exchangeable carbonate, iron oxide, organic, and inert fractions in both samples. Initial results in samples amended with carbon and nitrogen indicate immobilization of U due to enhanced indigenous microbial activity under anaerobic conditions. 23 refs., 4 figs., 5 tabs

  20. Integrative microbial community analysis reveals full-scale enhanced biological phosphorus removal under tropical conditions.

    Science.gov (United States)

    Law, Yingyu; Kirkegaard, Rasmus Hansen; Cokro, Angel Anisa; Liu, Xianghui; Arumugam, Krithika; Xie, Chao; Stokholm-Bjerregaard, Mikkel; Drautz-Moses, Daniela I; Nielsen, Per Halkjær; Wuertz, Stefan; Williams, Rohan B H

    2016-01-01

    Management of phosphorus discharge from human waste is essential for the control of eutrophication in surface waters. Enhanced biological phosphorus removal (EBPR) is a sustainable, efficient way of removing phosphorus from waste water without employing chemical precipitation, but is assumed unachievable in tropical temperatures due to conditions that favour glycogen accumulating organisms (GAOs) over polyphosphate accumulating organisms (PAOs). Here, we show these assumptions are unfounded by studying comparative community dynamics in a full-scale plant following systematic perturbation of operational conditions, which modified community abundance, function and physicochemical state. A statistically significant increase in the relative abundance of the PAO Accumulibacter was associated with improved EBPR activity. GAO relative abundance also increased, challenging the assumption of competition. An Accumulibacter bin-genome was identified from a whole community metagenomic survey, and comparative analysis against extant Accumulibacter genomes suggests a close relationship to Type II. Analysis of the associated metatranscriptome data revealed that genes encoding proteins involved in the tricarboxylic acid cycle and glycolysis pathways were highly expressed, consistent with metabolic modelling results. Our findings show that tropical EBPR is indeed possible, highlight the translational potential of studying competition dynamics in full-scale waste water communities and carry implications for plant design in tropical regions. PMID:27193869

  1. PGPR enhanced phytoremediation of petroleum contaminated soil and rhizosphere microbial community response.

    Science.gov (United States)

    Hou, Jinyu; Liu, Wuxing; Wang, Beibei; Wang, Qingling; Luo, Yongming; Franks, Ashley E

    2015-11-01

    The aim of this study was to investigate petroleum phytoremediation enhancement by plant growth promoting bacteria (PGPR), specifically the correlation between petroleum hydrocarbon fractions and bacterial community structure affected by remediation and PGPR inocula. Aged petroleum contaminated soil was remediated by tall fescue (Testuca arundinacea L.) inoculated with two PGPR strains. Hydrocarbon degradation was measured by GC-MS (Gas-chromatography Mass-spectrometer) based on carbon fraction numbers (C8-C34). Changes in bacterial community structure were analyzed by high-throughput pyrosequencing of 16s rRNA. PGPR inoculation increased tall fescue biomass and petroleum hydrocarbons were removed in all the treatments. Maximum hydrocarbon removal, particular high molecular weight (C21-C34) aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs), was observed in tall fescue inoculated with PGPR. The relative abundance of phyla γ-proteobacteria and Bacteroidetes increased after different treatments compared with controls. Moreover, a bacterial guild mainly comprising the genera Lysobacter, Pseudoxanthomonas, Planctomyces, Nocardioides, Hydrogenophaga, Ohtaekwangia was found to be positively correlated with C21-C34 petroleum hydrocarbons fractions removal by RDA analysis, implying that petroleum degradation was unrelated to bacterial community diversity but positively correlated with specific petroleum degraders and biosurfactant producers. PMID:26210024

  2. Integrative microbial community analysis reveals full-scale enhanced biological phosphorus removal under tropical conditions

    Science.gov (United States)

    Law, Yingyu; Kirkegaard, Rasmus Hansen; Cokro, Angel Anisa; Liu, Xianghui; Arumugam, Krithika; Xie, Chao; Stokholm-Bjerregaard, Mikkel; Drautz-Moses, Daniela I.; Nielsen, Per Halkjær; Wuertz, Stefan; Williams, Rohan B. H.

    2016-01-01

    Management of phosphorus discharge from human waste is essential for the control of eutrophication in surface waters. Enhanced biological phosphorus removal (EBPR) is a sustainable, efficient way of removing phosphorus from waste water without employing chemical precipitation, but is assumed unachievable in tropical temperatures due to conditions that favour glycogen accumulating organisms (GAOs) over polyphosphate accumulating organisms (PAOs). Here, we show these assumptions are unfounded by studying comparative community dynamics in a full-scale plant following systematic perturbation of operational conditions, which modified community abundance, function and physicochemical state. A statistically significant increase in the relative abundance of the PAO Accumulibacter was associated with improved EBPR activity. GAO relative abundance also increased, challenging the assumption of competition. An Accumulibacter bin-genome was identified from a whole community metagenomic survey, and comparative analysis against extant Accumulibacter genomes suggests a close relationship to Type II. Analysis of the associated metatranscriptome data revealed that genes encoding proteins involved in the tricarboxylic acid cycle and glycolysis pathways were highly expressed, consistent with metabolic modelling results. Our findings show that tropical EBPR is indeed possible, highlight the translational potential of studying competition dynamics in full-scale waste water communities and carry implications for plant design in tropical regions. PMID:27193869

  3. In situ stimulation vs. bioaugmentation: Can microbial inoculation of plant roots enhance biodegradation of organic compounds?

    Energy Technology Data Exchange (ETDEWEB)

    Kingsley, M.T.; Metting, F.B. Jr.; Fredrickson, J.K. [Pacific Northwest Lab., Richland, WA (United States); Seidler, R.J. [Environmental Protection Agency, Corvallis, OR (United States). Environmental Research Lab.

    1993-06-01

    The use of plant roots and their associated rhizosphere bacteria for biocontainment and biorestoration offers several advantages for treating soil-dispersed contaminants and for application to large land areas. Plant roots function as effective delivery systems, since root growth transports bacteria vertically and laterally along the root in the soil column (see [ 1,2]). Movement of microbes along roots and downward in the soil column can be enhanced via irrigation [1-4]. For example, Ciafardini et al. [3] increased the nodulation and the final yield of soybeans during pod filling by including Bradyrhizobium japonicum in the irrigation water. Using rhizosphere microorganisms is advantageous for biodegradation of compounds that are degraded mainly by cometabolic processes, e.g., trichloroethylene (TCE). The energy source for bacterial growth and metabolism is supplied by the plant in the form of root exudates and other sloughed organic material. Plants are inexpensive, and by careful choice of species that possess either tap or fibrous root growth patterns, they can be used to influence mass transport of soil contaminants to the root surface via the transpiration stream [5]. Cropping of plants to remove heavy metals from contaminated soils has been proposed as a viable, low-cost, low-input treatment option [6]. The interest in use of plants as a remediation strategy has even reached the popular press [7], where the use of ragweed for the reclamation of sites contaminated with tetraethyl lead and other heavy metals was discussed.

  4. Integrative microbial community analysis reveals full-scale enhanced biological phosphorus removal under tropical conditions

    Science.gov (United States)

    Law, Yingyu; Kirkegaard, Rasmus Hansen; Cokro, Angel Anisa; Liu, Xianghui; Arumugam, Krithika; Xie, Chao; Stokholm-Bjerregaard, Mikkel; Drautz-Moses, Daniela I.; Nielsen, Per Halkjær; Wuertz, Stefan; Williams, Rohan B. H.

    2016-05-01

    Management of phosphorus discharge from human waste is essential for the control of eutrophication in surface waters. Enhanced biological phosphorus removal (EBPR) is a sustainable, efficient way of removing phosphorus from waste water without employing chemical precipitation, but is assumed unachievable in tropical temperatures due to conditions that favour glycogen accumulating organisms (GAOs) over polyphosphate accumulating organisms (PAOs). Here, we show these assumptions are unfounded by studying comparative community dynamics in a full-scale plant following systematic perturbation of operational conditions, which modified community abundance, function and physicochemical state. A statistically significant increase in the relative abundance of the PAO Accumulibacter was associated with improved EBPR activity. GAO relative abundance also increased, challenging the assumption of competition. An Accumulibacter bin-genome was identified from a whole community metagenomic survey, and comparative analysis against extant Accumulibacter genomes suggests a close relationship to Type II. Analysis of the associated metatranscriptome data revealed that genes encoding proteins involved in the tricarboxylic acid cycle and glycolysis pathways were highly expressed, consistent with metabolic modelling results. Our findings show that tropical EBPR is indeed possible, highlight the translational potential of studying competition dynamics in full-scale waste water communities and carry implications for plant design in tropical regions.

  5. The Effect of Salt Concentration on Microbes during Microbial Enhanced Oil Recovery

    Directory of Open Access Journals (Sweden)

    Nmegbu, Chukwuma Godwin Jacob

    2014-06-01

    Full Text Available Reservoir fluid salinity, its effectiveness on viscosity as well as temperature dependency is an important parameter for enhanced oil recovery consideration. Previous studies on formation fluid properties focused on NaCl and KCl, the two most common brines in connate water and in water-based drilling mud, failing, however, to relate its performance to bacterial survival. This work has considered four different brine solutions and how it will affect the useability of pseudomonas species and halobacterium H – 356. The bacterial mixture viscosity shows a considerable difference between NaCl, CsCl, KCl and LiCl with NaCl and LiCl being favourable brines. Hence, for flooding agent at varying temperature since it makes the bacteria mixture viscosity more viscous whereas the KCl appeared less viscous compared to liquid mixture standard water. For the bacteria mixture, the viscosity of KCl and CsCl decreases with the concentration of a low temperature range and increases with the concentration at a high range.

  6. Enhanced Microbial, Functional and Sensory Properties of Herbal Yogurt Fermented with Korean Traditional Plant Extracts.

    Science.gov (United States)

    Joung, Jae Yeon; Lee, Ji Young; Ha, Young Sik; Shin, Yong Kook; Kim, Younghoon; Kim, Sae Hun; Oh, Nam Su

    2016-01-01

    This study evaluated the effects of two Korean traditional plant extracts (Diospyros kaki THUNB. leaf; DK, and Nelumbo nucifera leaf; NN) on the fermentation, functional and sensory properties of herbal yogurts. Compared to control fermentation, all plant extracts increased acidification rate and reduced the time to complete fermentation (pH 4.5). Supplementation of plant extracts and storage time were found to influence the characteristics of the yogurts, contributing to increased viability of starter culture and phenolic compounds. In particular, the increase in the counts of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus was highest (2.95 and 1.14 Log CFU/mL respectively) in DK yogurt. Furthermore, supplementation of the plant extracts significantly influenced to increase the antioxidant activity and water holding capacity and to produce volatile compounds. The higher antioxidant activity and water holding capacity were observed in NN yogurt than DK yogurt. Moreover, all of the sensory characteristics were altered by the addition of plant extracts. Addition of plant extracts increased the scores related to flavor, taste, and texture from plain yogurt without a plant extract, as a result of volatile compounds analysis. Thus, the overall preference was increased by plant extracts. Consequently, supplementation of DK and NN extracts in yogurt enhanced the antioxidant activity and physical property, moreover increased the acceptability of yogurt. These findings demonstrate the possibility of using plant extracts as a functional ingredient in the manufacture of herbal yogurt. PMID:27499669

  7. Methane production enhancement by an independent cathode in integrated anaerobic reactor with microbial electrolysis.

    Science.gov (United States)

    Cai, Weiwei; Han, Tingting; Guo, Zechong; Varrone, Cristiano; Wang, Aijie; Liu, Wenzong

    2016-05-01

    Anaerobic digestion (AD) represents a potential way to achieve energy recovery from waste organics. In this study, a novel bioelectrochemically-assisted anaerobic reactor is assembled by two AD systems separated by anion exchange membrane, with the cathode placing in the inside cylinder (cathodic AD) and the anode on the outside cylinder (anodic AD). In cathodic AD, average methane production rate goes up to 0.070mLCH4/mL reactor/day, which is 2.59times higher than AD control reactor (0.027m(3)CH4/m(3)/d). And COD removal is increased ∼15% over AD control. When changing to sludge fermentation liquid, methane production rate has been further increased to 0.247mLCH4/mL reactor/day (increased by 51.53% comparing with AD control). Energy recovery efficiency presents profitable gains, and economic revenue from increased methane totally self-cover the cost of input electricity. The study indicates that cathodic AD could cost-effectively enhance methane production rate and degradation of glucose and fermentative liquid. PMID:26913643

  8. Enhanced and stabilized arsenic retention in microcosms through the microbial oxidation of ferrous iron by nitrate.

    Science.gov (United States)

    Sun, Jing; Chillrud, Steven N; Mailloux, Brian J; Stute, Martin; Singh, Rajesh; Dong, Hailiang; Lepre, Christopher J; Bostick, Benjamin C

    2016-02-01

    Magnetite strongly retains As, and is relatively stable under Fe(III)-reducing conditions common in aquifers that release As. Here, laboratory microcosm experiments were conducted to investigate a potential As remediation method involving magnetite formation, using groundwater and sediments from the Vineland Superfund site. The microcosms were amended with various combinations of nitrate, Fe(II) (aq) (as ferrous sulfate) and lactate, and were incubated for more than 5 weeks. In the microcosms enriched with 10 mM nitrate and 5 mM Fe(II) (aq), black magnetic particles were produced, and As removal from solution was observed even under sustained Fe(III) reduction stimulated by the addition of 10 mM lactate. The enhanced As retention was mainly attributed to co-precipitation within magnetite and adsorption on a mixture of magnetite and ferrihydrite. Sequential chemical extraction, X-ray absorption spectroscopy and magnetic susceptibility measurements showed that these minerals formed at pH 6-7 following nitrate-Fe(II) addition, and As-bearing magnetite was stable under reducing conditions. Scanning electron microscopy and X-ray diffraction indicated that nano-particulate magnetite was produced as coatings on fine sediments, and no aging effect was detected on morphology over the course of incubation. These results suggest that a magnetite based strategy may be a long-term remedial option for As-contaminated aquifers. PMID:26454120

  9. The impact of microbial biotransformation of catechin in enhancing the allelopathic effects of Rhododendron formosanum.

    Science.gov (United States)

    Wang, Chao-Min; Li, Tsai-Chi; Jhan, Yun-Lian; Weng, Jen-Hsien; Chou, Chang-Hung

    2013-01-01

    Rhododendron formosanum is distributed widely in the central mountains in Taiwan and the major allelopathic compound in the leaves has been identified as (-)-catechin, which is also a major allelochemical of an invasive spotted knapweed in North America. Soil microorganisms play key roles in ecosystems and influence various important processes, including allelopathy. However, no microorganism has been identified as an allelochemical mediator. This study focused on the role of microorganisms in the allelopathic effects of R. formosanum. The microorganism population in the rhizosphere of R. formosanum was investigated and genetic analysis revealed that the predominant genera of microorganisms in the rhizosphere of R. formosanum were Pseudomonas, Herbaspirillum, and Burkholderia. The dominant genera Pseudomonas utilized (-)-catechin as the carbon source and catalyzed the conversion of (-)-catechin into protocatechuic acid in vitro. The concentrations of allelochemicals in the soil were quantified by liquid chromatography-electrospray ionization/tandem mass spectrometry. The concentration of (-)-catechin in the soil increased significantly during the extreme rainfall in the summer season and suppressed total bacterial populations. Protocatechuic acid accumulation was observed while total bacterial populations increased abundantly in both laboratory and field studies. Allelopathic interactions were tested by evaluating the effects of different allelochemicals on the seed germination, radicle growth, and photosynthesis system II of lettuce. Protocatechuic acid exhibited higher phytotoxicity than (-)-catechin did and the effect of (-)-catechin on the inhibition of seed germination was enhanced by combining it with protocatechuic acid at a low concentration. This study revealed the significance of the allelopathic interactions between R. formosanum and microorganisms in the rhizosphere. These findings demonstrate that knowledge regarding the precise biotransformation

  10. Low-cost separators for enhanced power production and field application of microbial fuel cells (MFCs)

    International Nuclear Information System (INIS)

    Highlights: • Several new separators were investigated for enhanced performance of MFC. • Polypropylen80 exhibited higher power and proton/ion diffusion compared to Nafion. • Low cost separators could be used for field application of MFC. - Abstract: New and different separators were investigated as alternatives to well-known ion exchange separators such as Nafion and Cation Exchange membrane (CMI). In polarization tests, the maximum power densities of new separators without functional groups were comparatively higher than those of Nafion and CMI. The non-woven fabric Polypropylene (PP80) exhibited maximum voltage of 0.477 V (with 1000 Ω), which was similar to that of Nafion (0.481 V), and resulted in the highest power density of 121 mW/m2 (Nafion; 118 mW/m2). Polypropylene 80 and 100 exhibited relatively smaller ohmic resistances of 11 Ω and 2 Ω, respectively, compared to others with resistances ranging from 13 to 41 Ω. Concerning oxygen diffusion, all types of size selective separators exhibited high oxygen mass transfer compared to Nafion and CMI. This high oxygen diffusion was likely the reason for the lower columbic efficiencies (CE) of PP80 (44%) and PP100 (42%) compared to Nafion (50%). PP80 exhibited a high proton mass transfer coefficient (KH = 11 × 10−5cm/s) compared to all ion exchange and size selective separators included in this study. These results suggest that low-cost separators could be used for field applications of MFCs for higher cell voltage while minimizing oxygen diffusion

  11. Harnessing microbial subsurface metal reduction activities to synthesise nanoscale cobalt ferrite with enhanced magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Coker, Victoria S.; Telling, Neil D.; van der Laan, Gerrit; Pattrick, Richard A.D.; Pearce, Carolyn I.; Arenholz, Elke; Tuna, Floriana; Winpenny, Richard E.P.; Lloyd, Jonathan R.

    2009-03-24

    Nanoscale ferrimagnetic particles have a diverse range of uses from directed cancer therapy and drug delivery systems to magnetic recording media and transducers. Such applications require the production of monodisperse nanoparticles with well-controlled size, composition, and magnetic properties. To fabricate these materials purely using synthetic methods is costly in both environmental and economical terms. However, metal-reducing microorganisms offer an untapped resource to produce these materials. Here, the Fe(III)-reducing bacterium Geobacter sulfurreducens is used to synthesize magnetic iron oxide nanoparticles. A combination of electron microscopy, soft X-ray spectroscopy, and magnetometry techniques was employed to show that this method of biosynthesis results in high yields of crystalline nanoparticles with a narrow size distribution and magnetic properties equal to the best chemically synthesized materials. In particular, it is demonstrated here that cobalt ferrite (CoFe{sub 2}O{sub 4}) nanoparticles with low temperature coercivity approaching 8 kOe and an effective anisotropy constant of {approx} 10{sup 6} erg cm{sup -3} can be manufactured through this biotechnological route. The dramatic enhancement in the magnetic properties of the nanoparticles by the introduction of high quantities of Co into the spinel structure represents a significant advance over previous biomineralization studies in this area using magnetotactic bacteria. The successful production of nanoparticulate ferrites achieved in this study at high yields could open up the way for the scaled-up industrial manufacture of nanoparticles using environmentally benign methodologies. Production of ferromagnetic nanoparticles for pioneering cancer therapy, drug delivery, chemical sensors, catalytic activity, photoconductive materials, as well as more traditional uses in data storage embodies a large area of inorganic synthesis research. In particular, the addition of transition metals other than

  12. Relative Effects of Biological Amendments and Crop Rotations on Soil Microbial Communities and Soilborne Diseases of Potato

    Science.gov (United States)

    Various biological amendments, including commercial biocontrol agents, microbial inoculants, mycorrhizae, and an aerobic compost tea (ACT), were evaluated, alone and in conjunction with different crop rotations, for their efficacy in introducing beneficial microorganisms, affecting soil microbial co...

  13. Organic acid dipping of catfish fillets: effect on color, microbial load, and Listeria monocytogenes.

    Science.gov (United States)

    Bal'a, M F; Marshall, D L

    1998-11-01

    Microbiological and color changes of catfish fillets were determined following dip treatment in solutions at 4 degrees C of 2% acetic, citric, hydrochloric, lactic, malic, or tartaric acid. Fillets were inoculated with an eight-strain mixture of Listeria monocytogenes prior to dipping. L. monocytogenes, coliform, and aerobic plate counts and surface pH and Hunter color were measured at 0, 2, 5, and 8 days of storage at 4 degrees C. Acid dipping reduced surface pH and L. monocytogenes, coliform, and aerobic microbial loads. Little microbial proliferation was observed on acid-treated fillets, however, controls had a distinct foul odor and microbial loads in excess of 10(6) CFU/g by day 8. On untreated fillets, L. monocytogenes counts did not increase during storage, perhaps due to competitive inhibition by normal catfish microflora. Hunter color analysis revealed lighter and yellower acid-treated fillets than untreated controls, with malic acid producing the least bleaching. The shelf life of refrigerated fillets increased when fillets were acid dipped. It remains to be established if this enhanced microbial quality also parallels sensory acceptability. PMID:9829187

  14. Gas Production Generated from Crude Oil Biodegradation: Preliminary Study on its Aplication in Microbial Enhanced Oil Recovery (MEOR

    Directory of Open Access Journals (Sweden)

    Astri Nugroho

    2009-11-01

    Full Text Available Gas Production Generated from Crude Oil Biodegradation: Preliminary Study on its Aplication in MicrobialEnhanced Oil Recovery (MEOR. The objective of this study is to observe the capacity of gas production generatedfrom crude oil degradation by the isolated bacteria. The gas in the MEOR could increase pressure in the reservoir,decrease oil viscosity, increase oil permeability-due to the increase of the porosity and viscosity, and also increase oilvolume due to the amount of dissolved gas. A research on gas analysis of oil degradation by 6 isolated bacteria has beenconducted. The bacteria isolates including Bacillus badius (A, Bacillus circulans (B, Bacillus coagulans (C, Bacillusfirmus (D, Pasteurella avium (E and Streptobacillus moniliformis (F. The trial on gas production, gas analysis and oildegradation analysis, was carried out by using SMSS medium. The test of gas production was done by usingmicrorespirometer at 40°C. The result shows that B, C, D, E produce more gas than A and F. Gas of CO2, O2, CO, N2,CH4, and H2 were analyzed by using GC. The results show that only three gases were detected by GC i.e. CO2, N2, andO2. The concentration of CO2 and N2 gas increased while the concentration of O2 decreased over an 8th day ofobservation. CO2 gas producted by mix culture was higher than by the pure culture. On the 8th day of incubation, theproduction of CO2 gas by mix culture was 4,0452% while pure culture C and D only produced 2,4543% and 2,8729%.The mix culture increase simple hydrocarbon by 12.03% and the formation of a complex hydrocarbon by 3.07%. Themix culture (C-D generated the highest concentration of CO2 gas as well as a synergistic concortium that has ability todegrade crude oil.

  15. Three-dimensional graphene/Pt nanoparticle composites as freestanding anode for enhancing performance of microbial fuel cells.

    Science.gov (United States)

    Zhao, Shenlong; Li, Yuchen; Yin, Huajie; Liu, Zhouzhou; Luan, Enxiao; Zhao, Feng; Tang, Zhiyong; Liu, Shaoqin

    2015-11-01

    Microbial fuel cells (MFCs) are able to directly convert about 50 to 90% of energy from oxidation of organic matters in waste to electricity and have great potential application in broad fields such as wastewater treatment. Unfortunately, the power density of the MFCs at present is significantly lower than the theoretical value because of technical limitations including low bacteria loading capacity and difficult electron transfer between the bacteria and the electrode. We reported a three-dimensional (3D) graphene aerogel (GA) decorated with platinum nanoparticles (Pt NPs) as an efficient freestanding anode for MFCs. The 3D GA/Pt-based anode has a continuous 3D macroporous structure that is favorable for microorganism immobilization and efficient electrolyte transport. Moreover, GA scaffold is homogenously decorated with Pt NPs to further enhance extracellular charge transfer between the bacteria and the anode. The MFCs constructed with 3D GA/Pt-based anode generate a remarkable maximum power density of 1460 mW/m(2), 5.3 times higher than that based on carbon cloth (273 mW/m(2)). It deserves to be stressed that 1460 mW/m(2) obtained from the GA/Pt anode shows the superior performance among all the reported MFCs inoculated with Shewanella oneidensis MR-1. Moreover, as a demonstration of the real application, the MFC equipped with the freestanding GA/Pt anode has been successfully applied in driving timer for the first time, which opens the avenue toward the real application of the MFCs. PMID:26702430

  16. Functionalization of electrochemically deposited chitosan films with alginate and Prussian blue for enhanced performance of microbial fuel cells

    International Nuclear Information System (INIS)

    Highlights: • Preparation of biocompatible chitosan–alginate electrode. • The synergism between Acetobacter aceti and Gluconobacter roseus. • Better biofilm formation and enhanced electricity generation. • Immobilized Prussian blue system replaces the conventional ferricyanide system. - Abstract: This work is aimed at finding new strategies for the modification of anode and cathode that can lead to improved performance of microbial fuel cells (MFCs). The electrochemical deposition of chitosan onto carbon felt followed by further modification with alginate led to the formation of a biocompatible platform for the prolific growth of microorganisms on the anode (Chit–Alg/carbon felt anode). The novel modification strategy for the formation of Prussian blue film, on the electrochemically deposited chitosan layer, has helped in circumventing the disadvantages of using ferricyanide in the cathode compartment and also for improving the electron transfer characteristics of the film in phosphate buffer. The anode was tested for its efficacy with four different substrates viz., glucose, ethanol, acetate and grape juice in a two compartment MFC. The synergistic effect of the mixed culture of Acetobacter aceti and Gluconobacter roseus was utilized for current generation. The electrocatalytic activity of the biofilm and its morphology were characterized by cyclic voltammetry and scanning electron microscopy, respectively. The power densities were found to be 1.55 W/m3, 2.80 W/m3, 1.73 W/m3 and 3.87 W/m3 for glucose, ethanol, acetate and grape juice, respectively. The performance improved by 20.75% when compared to the bare electrode

  17. High quality residues from cover crops favor changes in microbial community and enhance C and N sequestration

    OpenAIRE

    Ileana Frasier; Elke Noellemeyer; Eva Figuerola; Leonardo Erijman; Hugo Permingeat; Alberto Quiroga

    2016-01-01

    The objective of the study was to evaluate the effect of a change in management on the soil microbial community and C sequestration. We conducted a 3-year field study in La Pampa (Argentina) with rotation of sorghum (Sorghum bicolor) in zero tillage alternating with rye (Secale cereale) and vetch (Vicia villosa ssp. dasycarpa). Soil was sampled once a year at two depths. Soil organic matter fractions, dissolved organic matter, microbial biomass (MBC) and community composition (DNA extraction,...

  18. The impact of microbial ecology and chemical profile on the enhanced biological phosphorus removal (EBPR) process: a case study of Northern Wastewater Treatment Works, Johannesburg.

    Science.gov (United States)

    Kamika, Ilunga; Coetzee, Martie; Mamba, Bhekie Brilliance; Msagati, Titus; Momba, Maggy N B

    2014-03-01

    The impact of polyphosphate-accumulating organism (PAO) and glycogen-accumulating organism (GAO) populations as well as of the chemical profile on the performance of Unit-3 (open elutriation tanks) and Unit-5 (covered elutriation tank) of the City of Johannesburg Northern Wastewater Treatment Works was determined. Physicochemical parameters of wastewater samples were measured using standard methods. Bacterial diversity was determined using 16S rRNA gene amplicon pyrosequencing of the variable region V1-3. Results showed soluble COD concentrations from settled sewage for Unit-3 at 192.8 mg COD/L and for Unit-5 at 214.6 mg COD/L, which increased to 301.8 mg COD/L and 411.6 mg COD/L in the overflow from elutriation tanks and decreased to 170.9 mg COD/L and 256.3 mg COD/L at the division boxes, respectively. Both long-chain volatile fatty acids (heptanoic acid, isobutyric acid, 3-methylbutanoic acid, pentanoic acid, 4-methylpentanoic acid, methylheptanoic acid) and short-chain volatile fatty acids (acetic acid, propionic acid, isobutyric acid) were present within concentration ranges of 17.19 mg/L to 54.98 mg/L and 13.64 mg/L to 87.6 mg/L for Unit 3 and 38.61 mg/L to58.85 mg/L and 21.63 mg/L to 92.39 mg/L for Unit 5, respectively. In the secondary settling tanks, the phosphate-removal efficiency in Unit-5 appeared to be slightly higher (0.08 mg P/L) compared to that of Unit-3 (0.11 mg P/L). The average DO concentrations (2.1 mg/L and 2.2 mg/L) as well as the pH values (pH 7 to pH 7.5) were found to be slightly higher in Unit-5 in the aerobic zones. The high presence of PAOs in the bioreactors (Unit-5: Dechloromonas (14.96%), Acinetobacter (6.3%), Zoogloea (4.72%) in the anaerobic zone and Dechloromonas (22.37 %) in the aerobic zone; Unit-3: Dechloromonas (37.25%) in the anaerobic zone and Dechloromonas (23.97%) in the aerobic zone) confirmed the phosphate-removal efficiencies of both units. Negligible GAOs were found in the aerobic zones (Defluviicoccus spp.: 0.33% for

  19. The Impact of Microbial Ecology and Chemical Profile on the Enhanced Biological Phosphorus Removal (EBPR Process: A Case Study of Northern Wastewater Treatment Works, Johannesburg

    Directory of Open Access Journals (Sweden)

    Ilunga Kamika

    2014-03-01

    Full Text Available The impact of polyphosphate-accumulating organism (PAO and glycogen-accumulating organism (GAO populations as well as of the chemical profile on the performance of Unit-3 (open elutriation tanks and Unit-5 (covered elutriation tank of the City of Johannesburg Northern Wastewater Treatment Works was determined. Physicochemical parameters of wastewater samples were measured using standard methods. Bacterial diversity was determined using 16S rRNA gene amplicon pyrosequencing of the variable region V1-3. Results showed soluble COD concentrations from settled sewage for Unit-3 at 192.8 mg COD/L and for Unit-5 at 214.6 mg COD/L, which increased to 301.8 mg COD/L and 411.6 mg COD/L in the overflow from elutriation tanks and decreased to 170.9 mg COD/L and 256.3 mg COD/L at the division boxes, respectively. Both long-chain volatile fatty acids (heptanoic acid, isobutyric acid, 3-methylbutanoic acid, pentanoic acid, 4-methylpentanoic acid, methylheptanoic acid and short-chain volatile fatty acids (acetic acid, propionic acid, isobutyric acid were present within concentration ranges of 17.19 mg/L to 54.98 mg/L and 13.64 mg/L to 87.6 mg/L for Unit 3 and 38.61 mg/L to58.85 mg/L and 21.63 mg/L to 92.39 mg/L for Unit 5, respectively. In the secondary settling tanks, the phosphate-removal efficiency in Unit-5 appeared to be slightly higher (0.08 mg P/L compared to that of Unit-3 (0.11 mg P/L. The average DO concentrations (2.1 mg/L and 2.2 mg/L as well as the pH values (pH 7 to pH 7.5 were found to be slightly higher in Unit-5 in the aerobic zones. The high presence of PAOs in the bioreactors (Unit-5: Dechloromonas (14.96%, Acinetobacter (6.3%, Zoogloea (4.72% in the anaerobic zone and Dechloromonas (22.37 % in the aerobic zone; Unit-3: Dechloromonas (37.25% in the anaerobic zone and Dechloromonas (23.97% in the aerobic zone confirmed the phosphate-removal efficiencies of both units. Negligible GAOs were found in the aerobic zones (Defluviicoccus spp.: 0

  20. Annular purpura and step aerobics.

    Science.gov (United States)

    Allan, S J; Humphreys, F; Buxton, P K

    1994-09-01

    Step aerobic classes are at present one of the most popular forms of exercise undertaken by young adults. To date no dermatological abnormalities have been described in people regularly performing step aerobics. We describe a case in which a healthy young woman developed an extensive pigmented purpuric eruption 4 weeks after commencing regular step aerobic classes. The eruption resolved completely 8 weeks after regular exercise was ceased. PMID:7955503

  1. Numerical modelling of biophysicochemical effects on multispecies reactive transport in porous media involving Pseudomonas putida for potential microbial enhanced oil recovery application.

    Science.gov (United States)

    Sivasankar, P; Rajesh Kanna, A; Suresh Kumar, G; Gummadi, Sathyanarayana N

    2016-07-01

    pH and resident time of injected slug plays a critical role in characterizing the reservoir for potential microbial enhanced oil recovery (MEOR) application. To investigate MEOR processes, a multispecies (microbes-nutrients) reactive transport model in porous media was developed by coupling kinetic and transport model. The present work differs from earlier works by explicitly determining parametric values required for kinetic model by experimental investigations using Pseudomonas putida at different pH conditions and subsequently performing sensitivity analysis of pH, resident time and water saturation on concentrations of microbes, nutrients and biosurfactant within reservoir. The results suggest that nutrient utilization and biosurfactant production are found to be maximum at pH 8 and 7.5 respectively. It is also found that the sucrose and biosurfactant concentrations are highly sensitive to pH rather than reservoir microbial concentration, while at larger resident time and water saturation, the microbial and nutrient concentrations were lesser due to enhanced dispersion. PMID:27030954

  2. APPLICATION AND PERSPECTIVES OF DEVELOPMENT OF AEROBIC GRANULAR SLUDGE TECHNOLOGY IN WASTEWATER TREATMENT

    OpenAIRE

    Agnieszka Cydzik-Kwiatkowska

    2014-01-01

    Recently an extensive studies have been carried out on aerobic granular sludge technology in both laboratory and technical scale. Aerobic granules are compact, spherical microbial consortia created by a spontaneous immobilization. Amongst their advantages are a very good settling ability, long biomass age and simultaneous pollutant removal in the granule structure that enables full biological treatment of wastewater in a single reactor. This review outlines up-to-date information on granule f...

  3. Aerobic landfill bioreactor

    Science.gov (United States)

    Hudgins, Mark P; Bessette, Bernard J; March, John; McComb, Scott T.

    2000-01-01

    The present invention includes a method of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120.degree. F. and 140.degree. F. in steady state.

  4. Understanding the impact of influent nitrogen concentration on granule size and microbial community in a granule-based enhanced biological phosphorus removal system.

    Science.gov (United States)

    Zou, Jinte; Li, Yongmei; Zhang, Lili; Wang, Ruyi; Sun, Jing

    2015-02-01

    To better understand the effect of influent nitrogen concentration on granule size and microbial community in a granule-based enhanced biological phosphorus removal system, three influent nitrogen concentrations were tested while carbon concentration was an unlimited factor. The results show that although ammonium and phosphate were well removed in the tested nitrogen concentration range (20-50 mg L(-1)), granule size, the amount of phosphate accumulating organisms (PAOs) and microbial activity were affected significantly. A possible mechanism for the effect of influent nitrogen concentration on granule size is proposed based on the experimental results. The increase in proteins/polysaccharides ratio caused by high influent nitrogen concentration plays a crucial role in granule breakage. The small granule size then weakens simultaneous nitrification-denitrification, which further causes higher nitrate concentration in the effluent and lower amount of PAOs in sludge. Consequently, phosphate concentration in the anaerobic phase decreases, which plays the secondary role in granule breakage. PMID:25496940

  5. Comparison of Aerobic and Anaerobic Biodegradation of Sugarcane Vinasse.

    Science.gov (United States)

    Mota, V T; Araújo, T A; Amaral, M C S

    2015-07-01

    Vinasse is the main liquid waste from ethanol production, and it has a considerable pollution potential. Biological treatment is a promising alternative to reduce its organic load. The aim of this study was to analyze the biodegradation of sugarcane juice vinasse in aerobic and anaerobic conditions. The content of carbohydrates, proteins and volatile fatty acids was evaluated. Vinasse samples showed a high biodegradability (>96.5 %) and low percentage of inert chemical oxygen demand (COD) (<3.2 %) in both aerobic and anaerobic conditions. The rates of substrate utilization were slightly higher in aerobic reactors, but COD stabilization occurred simultaneously in the anaerobic reactors, confirming its suitability for anaerobic digestion. Inert COD in anaerobic conditions was lower than in aerobic conditions. On the other hand, COD from metabolic products in the anaerobic reactors was higher than in the aerobic ones, indicating an increased release of soluble microbial products (SMPs) by anaerobic microorganisms. The results indicated that carbohydrates were satisfactorily degraded and protein-like substances were the major components remaining after biological degradation of vinasse. PMID:25957273

  6. Insight into the mechanism of carbon steel corrosion under aerobic and anaerobic conditions.

    Science.gov (United States)

    El Mendili, Y; Abdelouas, A; Bardeau, J-F

    2013-06-21

    We particularly focused our study on identifying the corrosion products formed at 30 °C on carbon steel under aerobic and anaerobic conditions and on following their evolution with time due to enhanced microbial activity under environmental and geological conditions. The nature and structural properties of corrosion products were investigated by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS), X-ray diffraction (XRD) and confocal micro-Raman spectroscopy. Structural characterisation clearly showed the formation of iron oxides (magnetite and maghemite) under aerobic conditions. Under anaerobic conditions, the first corrosion product formed on the steel surface was nanocrystalline mackinawite, which was then followed by a fast transformation process into the pyrrhotite phase, and the Raman spectrum of monoclinic pyrrhotite was proposed for the first time. Finally, this study also shows that in the context of geological disposal of radioactive waste, the corrosion of carbon steel containers in anoxic and sulphidogenic environments sustained by sulphate-reducing bacteria may not be a problem notably due to the formation of a passive layer on the steel surface. PMID:23652337

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

    DEFF Research Database (Denmark)

    Vlaeminck, S.E.; Terada, Akihiko; Smets, Barth F.;

    2010-01-01

    Aerobic ammonium-oxidizing bacteria (AerAOB) and anoxic ammonium-oxidizing bacteria (AnAOB) cooperate in partial nitritation/anammox systems to remove ammonium from wastewater. In this process, large granular microbial aggregates enhance the performance, but little is known about granulation so far......AOB abundance and the activity balance for the different aggregate sizes and (ii) to relate aggregate morphology, size distribution, and architecture putatively to the inoculation and operation of the three reactors. A nitrite accumulation rate ratio (NARR) was defined as the net aerobic nitrite production rate...... divided by the anoxic nitrite consumption rate. The smallest reactor A, B, and C aggregates were nitrite sources (NARR, > 1.7). Large reactor A and C aggregates were granules capable of autonomous nitrogen removal (NARR, 0.6 to 1.1) with internal AnAOB zones surrounded by an AerAOB rim. Around 50% of the...

  8. Microbial community dynamics linked to enhanced substrate availability and biogas production of electrokinetically pre-treated waste activated sludge.

    Science.gov (United States)

    Westerholm, Maria; Crauwels, Sam; Houtmeyers, Sofie; Meerbergen, Ken; Van Geel, Maarten; Lievens, Bart; Appels, Lise

    2016-10-01

    The restricted hydrolytic degradation rate of complex organic matter presents a considerable challenge in anaerobic digestion of waste activated sludge (WAS). Within this context, application of pre-treatment of digester substrate has potential for improved waste management and enhanced biogas production. Anaerobic degradation of untreated or electrokinetically pre-treated WAS was performed in two pilot-scale digesters for 132days. WAS electrokinetically pre-treated with energy input 0.066kJ/kg sludge was used in a first phase of operation and WAS pre-treated with energy input 0.091kJ/kg sludge was used in a second phase (each phase lasted at least three hydraulic retention times). Substrate characteristics before and after pre-treatment and effects on biogas digester performance were comprehensively analysed. To gain insights into influences of altered substrate characteristics on microbial communities, the dynamics within the bacterial and archaeal communities in the two digesters were investigated using 16S rRNA gene sequencing (pyrosequencing) and quantitative PCR (qPCR). Specific primers targeting dominant operation taxonomic units (OTUs) and members of the candidate phylum Cloacimonetes were designed to further evaluate their abundance and dynamics in the digesters. Electrokinetic pre-treatment significantly improved chemical oxygen demand (COD) and carbohydrate solubility and increased biogas production by 10-11% compared with untreated sludge. Compositional similarity of the bacterial community during initial operation and diversification during later operation indicated gradual adaptation of the community to the higher solubility of organic material in the pre-treated substrate. Further analyses revealed positive correlations between gene abundance of dominant OTUs related to Clostridia and Cloacimonetes and increased substrate availability and biogas production. Among the methanogens, the genus Methanosaeta dominated in both digesters. Overall, the

  9. Microbial metabolism of Tholin

    Science.gov (United States)

    Stoker, C. R.; Mancinelli, R. L.; Boston, P. J.; Segal, W.; Khare, B. N.

    1990-01-01

    Tholin, a class of complex organic heteropolymers hypothesized to possess wide solar system distribution, is shown to furnish the carbon and energy requirements of a wide variety of common soil bacteria which encompasses aerobic, anaerobic, and facultatively anaerobic bacteria. Some of these bacteria are able to derive not merely their carbon but also their nitrogen requirements from tholin. The palatability of tholins to modern microbes is speculated to have implications for the early evolution of microbial life on earth; tholins may have formed the base of the food chain for an early heterotrophic biosphere, prior to the evolution of autotrophy on the early earth.

  10. Microbial remediation of explosive waste.

    Science.gov (United States)

    Singh, Baljinder; Kaur, Jagdeep; Singh, Kashmir

    2012-05-01

    Explosives are synthesized globally mainly for military munitions. Nitrate esters, such as GTN and PETN, nitroaromatics like TNP and TNT and nitramines with RDX, HMX and CL20, are the main class of explosives used. Their use has resulted in severe contamination of environment and strategies are now being developed to clean these substances in an economical and eco-friendly manner. The incredible versatility inherited in microbes has rendered these explosives as a part of the biogeochemical cycle. Several microbes catalyze mineralization and/or nonspecific transformation of explosive waste either by aerobic or anaerobic processes. It is likely that ongoing genetic adaptation, with the recruitment of silent sequences into functional catabolic routes and evolution of substrate range by mutations in structural genes, will further enhance the catabolic potential of bacteria toward explosives and ultimately contribute to cleansing the environment of these toxic and recalcitrant chemicals. This review summarizes information on the biodegradation and biotransformation pathways of several important explosives. Isolation, characterization, utilization and manipulation of the major detoxifying enzymes and the molecular basis of degradation are also discussed. This may be useful in developing safer and economic microbiological methods for clean up of soil and water contaminated with such compounds. The necessity of further investigations concerning the microbial metabolism of these substances is also discussed. PMID:22497284

  11. Lipid Biomarkers Indicating Aerobic Methanotrophy at Ancient Marine Methane- Seeps

    Science.gov (United States)

    Birgel, D.; Peckmann, J.

    2007-12-01

    The inventory of lipid biomarkers of a number of ancient methane-seep limestones has been studied over the last decade. The molecular fingerprints of the chemosynthesis-based microbial communities tend to be extremely well-preserved in these limestones. The key process at seeps is the anaerobic oxidation of methane, performed by consortia of sulfate-reducing bacteria and methanotrophic archaea. Compounds preserved within modern and ancient seep settings comprise C-13-depleted lipid biomarkers. Besides the occurrence of C-13- depleted isoprenoids (archaea) and n-alkyl-chains (bacteria), C-13-depleted hopanoids have been reported in seep limestones. Here, lipid biomarker data are presented from three ancient methane-seep limestones embedded in Miocene and Campanian strata. These examples provide strong evidence that methane was not solely oxidized by an anaerobic process. In a Miocene limestone, 3-beta-methylated hopanoids were found (delta C-13: -100 per mil). Most likely, 3-beta-methylated hopanepolyols, prevailing in aerobic methanotrophs were the precursor lipids. In another Miocene limestone, a series of C-13-depleted 4-methylated steranes (lanostanes; -80 to -70 per mil) is derived from aerobic methanotrophs. Lanosterol is the most likely precursor of lanostanes, known to be produced by aerobic methanotrophs, some of which are outstanding among bacteria in having the capacity to produce steroids. In a Campanian seep limestone a suite of conspicuous secohexahydrobenzohopanes (-110 to -107 per mil) is found. These hopanoids probably represent early degradation products of seep-endemic aerobic methanotrophs. This interpretation is supported by the presence of "regular" hopanoids that can be discriminated from the unusual secohexahydrobenzohopanes by only moderately low delta C-13 values (-49 to -42 per mil). Structural and carbon isotope data reveal that aerobic methanotrophy is more common at ancient methane- seeps than previously noticed. Our data indicate that

  12. Simultaneous inhibition of sulfate-reducing bacteria, removal of H2S and production of rhamnolipid by recombinant Pseudomonas stutzeri Rhl: Applications for microbial enhanced oil recovery.

    Science.gov (United States)

    Zhao, Feng; Zhou, Ji-Dong; Ma, Fang; Shi, Rong-Jiu; Han, Si-Qin; Zhang, Jie; Zhang, Ying

    2016-05-01

    Sulfate-reducing bacteria (SRB) are widely existed in oil production system, and its H2S product inhibits rhamnolipid producing bacteria. In-situ production of rhamnolipid is promising for microbial enhanced oil recovery. Inhibition of SRB, removal of H2S and production of rhamnolipid by recombinant Pseudomonas stutzeri Rhl were investigated. Strain Rhl can simultaneously remove S(2-) (>92%) and produce rhamnolipid (>136mg/l) under S(2-) stress below 33.3mg/l. Rhl reduced the SRB numbers from 10(9) to 10(5)cells/ml, and the production of H2S was delayed and decreased to below 2mg/l. Rhl also produced rhamnolipid and removed S(2-) under laboratory simulated oil reservoir conditions. High-throughput sequencing data demonstrated that addition of strain Rhl significantly changed the original microbial communities of oilfield production water and decreased the species and abundance of SRB. Bioaugmentation of strain Rhl in oilfield is promising for simultaneous control of SRB, removal of S(2-) and enhance oil recovery. PMID:26868152

  13. Effect of biochar on the fate of volatile petroleum hydrocarbons in an aerobic sandy soil

    Science.gov (United States)

    Bushnaf, Khaled M.; Puricelli, Sara; Saponaro, Sabrina; Werner, David

    2011-11-01

    Biochar addition to soil is currently being investigated as a novel technology to remediate polluted sites. A critical consideration is the impact of biochar on the intrinsic microbial pollutant degradation, in particular at sites polluted with a mixture of readily biodegradable and more persistent organic pollutants. We therefore studied the impact of biochar (2% on dry weight basis) on the fate of volatile petroleum hydrocarbons in an aerobic sandy soil with batch and column studies. The soil-water partitioning coefficient, K d, was enhanced in the biochar-amended soil up to a factor 36, and petroleum hydrocarbon vapor migration was retarded accordingly. Despite increased sorption, in particular of monoaromatic hydrocarbons, the overall microbial respiration was comparable in the biochar-amended and unamended soil. This was due to more rapid biodegradation of linear, cyclic and branched alkanes in the biochar amended soil. We concluded that the total petroleum hydrocarbon degradation rate was controlled by a factor other than substrate availability and the reduced availability of monoaromatic hydrocarbons in the biochar amended soil led to greater biodegradation of the other petroleum compounds.

  14. Coupling of microbial electrolysis cells and dark fermentation to enhance the production of hydrogen from agro-industrial wastewaters

    OpenAIRE

    Marone, Antonella; Ayala, Olga; Trably, Eric; Carmona Martinez, Alessandro; Moscoviz, Roman; Latrille, Eric; Alcaraz-Gonzalez, Victor; Bernet, Nicolas

    2015-01-01

    The aim of this work is the development of a feasible, cascade two-step BioH2 production process from Organic Wastewater (WW), combining dark fermentation (DF) and Microbial Electrolysis Cells (MECs). Such coupling of DF and ME constitutes a technological cornerstone within the concept of an environmental biorefinery. Five different WW coming from cheese (CW), fruit juice (FJW), paper (PW), sugar (SW) and fruit processing (FPW) factories were selected among 21 different WW collected from a wi...

  15. Team-Based Learning Enhances Long-Term Retention and Critical Thinking in an Undergraduate Microbial Physiology Course

    OpenAIRE

    MCINERNEY, MICHAEL J.; L. Dee Fink

    2009-01-01

    We used team-based learning to improve comprehension and critical thinking of students in an undergraduate microbial metabolism-physiology course. The course used well-known bacterial pathways to highlight themes of energy conservation and biodegradation. Prior to the introduction of team-based learning, student recall of this information was poor and students had difficulty extrapolating information to new organisms. Initially, individual and group quizzes were added to promote problem-solvi...

  16. Dietary microbial levan enhances cellular non-specific immunity and survival of common carp (Cyprinus carpio) juveniles.

    Science.gov (United States)

    Rairakhwada, Dina; Pal, A K; Bhathena, Z P; Sahu, N P; Jha, A; Mukherjee, S C

    2007-05-01

    A preliminary study with a 75days feeding trial was conducted to study the immunomodulatory effect of microbial levan on Cyprinus carpio juveniles. Five purified isonitrogenous and isocaloric diets with graded levels of levan, namely (T(1)) 0.1% levan, (T(2)) 0.2% levan, (T(3)) 0.5% levan, (T(4)) 1.0% levan, and a control group without levan were fed to five groups of fishes in triplicate. The total erythrocyte count and haemoglobin content was significantly (p0.05) when compared with the control group. The respiratory burst activity (NBT) of blood phagocytes and lysozyme activity was also highest in T(3) group. The relative survival percentage after challenge with Aeromonas hydrophila was highest (100%) in the T(3) group followed by 83.33% and 66.67% in the T(2) and T(4) groups, respectively. This suggests that microbial levan at 0.5% can be used as a dietary immunostimulant for C. carpio juveniles. This is the first report on microbial levan having an immunomodulatory effect on C. carpio. PMID:17158064

  17. Brain Plasticity and Aerobic Fitness

    OpenAIRE

    Thomas, Adam G.; Johansen-Berg, Heidi; Bandettini, Peter

    2014-01-01

    Regular aerobic exercise has a wide range of positive effects on health and cognition. Exercise has been demonstrated to provide a particularly powerful and replicable method of triggering a wide range of structural changes within both human and animal brains. However, the details and mechanisms of these changes remain poorly understood. This thesis undertakes a comprehensive examination of the relationship between brain plasticity and aerobic exercise. A large, longitudinal experiment ...

  18. Mood alterations in mindful versus aerobic exercise modes.

    Science.gov (United States)

    Netz, Yael; Lidor, Ronnie

    2003-09-01

    The results of most recent studies have generally indicated an improvement in mood after participation in aerobic exercise. However, only a few researchers have compared mindful modes of exercise with aerobic exercise to examine the effect of 1 single session of exercise on mood. In the present study, the authors assessed state anxiety, depressive mood, and subjective well-being prior to and following 1 class of 1 of 4 exercise modes: yoga, Feldenkrais (awareness through movement), aerobic dance, and swimming; a computer class served as a control. Participants were 147 female general curriculum and physical education teachers (mean age = 40.15, SD = 0.2) voluntarily enrolled in a 1-year enrichment program at a physical education college. Analyses of variance for repeated measures revealed mood improvement following Feldenkrais, swimming, and yoga but not following aerobic dance and computer lessons. Mindful low-exertion activities as well as aerobic activities enhanced mood in 1 single session of exercise. The authors suggest that more studies assessing the mood-enhancing benefits of mindful activities such as Feldenkrais and yoga are needed. PMID:14629072

  19. Isolation and Characteristics of a Microbial Consortium for Effectively Degrading Phenanthrene

    Institute of Scientific and Technical Information of China (English)

    Wang Jing; Xu Hongke; Guo Shaohui

    2007-01-01

    A microbial consortium (named W4) capable of aerobic biodegradation of solid phenanthrene as the sole source of carbon and energy was isolated by selective enrichment from petroleum-contaminated soil in the Henan oilfield,China. The strains of the consortium were identified as Sphingomonas cloacae, Rhizobium sp., Pseudomonas aeruginosa and Achromobacter xylosoxidans respectively by means of genetic methods. The major metabolites of phenanthrene were analyzed by gas chromatography-mass spectrometry (GC-MS). The biodegradation percentage of solid phenanthrene at 200 mg/L in liquid medium after 7 days of growth was greater than 99%. The degradation of phenanthrene was compared between individual predominant strains and the microbial consortium in different treatment processes. The microbial consortium showed a significant improvement of phenanthrene degradation rates in either static or shaking culture. The degradation percentage of phenanthrene by the consortium W4 decreased to some degree when C 16 coexisted, however it was hardly affected by C30. Furthermore, the ability of consortium W4 to remediate oil sludge from the Dagang oil refinery was studied by composting; and it was found that the consortium W4 could obviously remove polycyclic aromatic hydrocarbons (PAHs) and paraffinic hydrocarbons. All the results indicated that the microbial consortium W4 had a promising application in bioremediation of oil-contaminated environments and could be potentially used in microbial enhanced oil recovery (MEOR).

  20. Unravelling the reasons for disproportion in the ratio of AOB and NOB in aerobic granular sludge

    NARCIS (Netherlands)

    Winkler, M.K.H.; Bassin, J.P.; Kleerebezem, R.; Sorokin, D.Y.; Van Loosdrecht, M.C.M.

    2012-01-01

    In this study, we analysed the nitrifying microbial community (ammonium-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB)) within three different aerobic granular sludge treatment systems as well as within one flocculent sludge system. Granular samples were taken from one pilot plant run

  1. Exogenous IAA treatment enhances phytoremediation of soil contaminated with phenanthrene by promoting soil enzyme activity and increasing microbial biomass.

    Science.gov (United States)

    Li, Weiming; Wang, Dongsheng; Hu, Feng; Li, Huixin; Ma, Lili; Xu, Li

    2016-06-01

    In this study, we aimed to confirm that indole-3-acetic acid promotes plant uptake of phenanthrene (PHE), stimulates the activity of soil enzymes or microflora, and thereby accelerates the dissipation of PHE in soil. Four treatments were evaluated: PHE-contaminated soil planted with (1) ryegrass (T0), (2) ryegrass and supplemented with 1 mg kg(-1) indole-3-acetic acid (IAA) (T1), (3) ryegrass and supplemented with 5 mg kg(-1) IAA (T5), and (4) ryegrass and supplemented with 10 mg kg(-1) IAA (T10). After 30 days, PHE concentrations were lower for all treatments and the removal rate was 70.19, 89.17, 91.26, and 97.07 % for T0, T1, T5, and T10, respectively. PHE was only detected in the roots and not in the shoots. IAA facilitated the accumulation of PHE in the roots, and plants subjected to the T10 treatment had the highest levels. Exogenous IAA stimulated soil peroxidase activity in a dose-dependent manner, whereas soil polyphenoloxidase activity was not significantly increased, except in T10. Soil microbial biomass also increased in response to IAA treatment, particularly in T10. Furthermore, phospholipid fatty acid analysis showed that IAA treatment increased microbial biomass and alleviated environmental stress. Gram-positive bacteria are largely responsible for polycyclic aromatic hydrocarbon degradation, and we found that the ratio of gram-positive to gram-negative bacteria in the soil significantly increased as the IAA concentrations increased (P < 0.05). Correlation analysis indicated that the increase in soil microbial biomass, enzyme activity, and plant uptake of PHE promotes removal of PHE from the soil. PMID:26884240

  2. Role of metal/silicon semiconductor contact engineering for enhanced output current in micro-sized microbial fuel cells

    KAUST Repository

    Mink, Justine E.

    2013-11-25

    We show that contact engineering plays an important role to extract the maximum performance from energy harvesters like microbial fuel cells (MFCs). We experimented with Schottky and Ohmic methods of fabricating contact areas on silicon in an MFC contact material study. We utilized the industry standard contact material, aluminum, as well as a metal, whose silicide has recently been recognized for its improved performance in smallest scale integration requirements, cobalt. Our study shows that improvements in contact engineering are not only important for device engineering but also for microsystems. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Toxicity of vapor phase petroleum contaminants to microbial degrader communities

    International Nuclear Information System (INIS)

    Petroleum products constitute the largest quantity of synthetic organic chemical products produced in the US. They are comprised of mostly hydrocarbon constituents from many different chemical classes including alkenes, cycloalkanes, aromatic compounds, and polyaromatic hydrocarbons. Many petroleum constituents are classified as volatile organic compounds or VOCs. Petroleum products also constitute a major portion of environmental pollution. One emerging technology, with promise for applications to VOCs in subsurface soil environments, is bioventing coupled with soil vapor extraction. These technologies involve volatilization of contaminants into the soil gas phase by injection and withdrawal of air. This air movement causes enhancement of the aerobic microbial degradation of the mobilized vapors by the indigenous populations. This study investigated the effects of exposure of mixed, subsurface microbial communities to vapor phase petroleum constituents or vapors of petroleum mixtures. Soil slurries were prepared and plated onto mineral salts agar plates and exposed to vapor phase contaminants at equilibrium with pure product. Representative n-alkane, branched alkane, cycloalkane, and aromatic compounds were tested as well as petroleum product mixtures. Vapor exposure altered the numbers and morphologies of the colonies enumerated when compared to controls. However, even at high, equilibrium vapor concentrations, microbial degrader populations were not completely inhibited

  4. Microbial mobilization of plutonium and other actinides from contaminated soil.

    Science.gov (United States)

    Francis, A J; Dodge, C J

    2015-12-01

    We examined the dissolution of Pu, U, and Am in contaminated soil from the Nevada Test Site (NTS) due to indigenous microbial activity. Scanning transmission x-ray microscopy (STXM) analysis of the soil showed that Pu was present in its polymeric form and associated with Fe- and Mn- oxides and aluminosilicates. Uranium analysis by x-ray diffraction (μ-XRD) revealed discrete U-containing mineral phases, viz., schoepite, sharpite, and liebigite; synchrotron x-ray fluorescence (μ-XRF) mapping showed its association with Fe- and Ca-phases; and μ-x-ray absorption near edge structure (μ-XANES) confirmed U(IV) and U(VI) oxidation states. Addition of citric acid or glucose to the soil and incubated under aerobic or anaerobic conditions enhanced indigenous microbial activity and the dissolution of Pu. Detectable amount of Am and no U was observed in solution. In the citric acid-amended sample, Pu concentration increased with time and decreased to below detection levels when the citric acid was completely consumed. In contrast, with glucose amendment, Pu remained in solution. Pu speciation studies suggest that it exists in mixed oxidation states (III/IV) in a polymeric form as colloids. Although Pu(IV) is the most prevalent and generally considered to be more stable chemical form in the environment, our findings suggest that under the appropriate conditions, microbial activity could affect its solubility and long-term stability in contaminated environments. PMID:26406590

  5. 用营养缓释型生物填料强化好氧水处理过程%BIOMASS CARRIER WITH SLOW RELEASE OF NUTRIENTS FOR ENHANCED AEROBIC PROCESS

    Institute of Scientific and Technical Information of China (English)

    海景; 程江; 肖立军; 皮丕辉; 文秀芳; 杨卓如

    2008-01-01

    The conventional polyethylene (PE) biofilm carrier was modified by additives of hydroxyapatite (HAP), starch, bagasse, activated carbon and magnetic powder, for improving its hydrophilicity and providing nutrients for attached microbes in aerobic treatment of toxic wastewater. The slow release rate of nutrients may be controlled by the amount of bagasse and activated carbon supplemented in the carrier. The contact angle of the modified polyethylene surface decreased from 80° (with respect to polyethylene itself) to 59°, and the period of biofilm formation on the modified carrier with acclimated sludge reduced from 7 days (on PE carrier without additives) to 4 days. The results also showed that the biological degradation of phenol was enhanced by use of biofilm carriers supplemented with additives for slow release of nutrients. The biodegradation process was reduced from 19 h to 13 h for complete removal of 127.5 mg/L phenol from synthetic wastewater by using the modified carrier. The strength performance assay demonstrated that the modified carrier was suitable for long operation in practical application.%在普通聚乙烯生物填料中添加适量的羟基磷灰石(HAP)、淀粉、蔗渣、活性炭和磁粉,形成营养缓释型生物填料(改性填料),研究了所改性填料的表面结构、润湿性能、营养缓释性能和挂膜性能.结果表明,改性聚乙烯填料较普通聚乙烯填料水接触角减小26%,具有较好的营养缓释性能,挂膜时间缩短了3 d;好氧生物处理中完全去除125.5 mg/L的酚,采用普通聚乙烯填料需19 h,而采用改性填料只需13 h,填料改性后的机械强度符合长期使用要求.

  6. Enhancement of the sweep efficiency of waterflooding operations by the in-situ microbial population of petroleum reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.R.; Vadie, A.A.; Stephens, J.O.; Azadpour, A.

    1995-12-31

    Live cores were obtained from five reservoirs using special precautions to prevent contamination by exogenous microorganisms and minimize exposure to oxygen. The depths from which the cores were obtained ranged from 2,705 ft to 6,568 ft. Core plugs were cut radially from live cores, encased in heat-shrink plastic tubes, placed in core holders, and fitted with inlets and outlets. Nutrient additions stimulated the in-situ microbial population to increase, dissolve stratal material, produce gases, and release oil. Reduction in flow through the core plugs was observed in some cases, while in other cases flow was increased, probably due to the dissolution of carbonates in the formation. A field demonstration of the ability of the in-situ microbial population to increase oil recovery by blocking the more permeable zones of the reservoir is currently underway. This demonstration is being conducted in the North Blowhorn Creek Unit situated in Lamar County, Alabama. Live cores were obtained from a newly drilled well in the field and tested as described above. The field project involves four test patterns each including one injector, four to five producers, and a comparable control injector with its four to five producers. Nutrient injection in the field began November 1994.

  7. TLR ligands of ryegrass pollen microbial contaminants enhance Th1 and Th2 responses and decrease induction of Foxp3(hi) regulatory T cells.

    Science.gov (United States)

    Mittag, Diana; Varese, Nirupama; Scholzen, Anja; Mansell, Ashley; Barker, Gillian; Rice, Gregory; Rolland, Jennifer M; O'Hehir, Robyn E

    2013-03-01

    Microbial contamination of grass pollens could affect sensitization, subsequent allergic response, and efficacy of allergen-specific immunotherapy. We investigated whether bacterial immunomodulatory substances can direct PBMC responses of allergic and nonatopic subjects against ryegrass pollen (RGP) toward Th1, Th2, or regulatory T (Treg) cells. Aqueous extracts of RGP with high or low LPS were fractionated into large and small molecular weight (MW) components by diafiltration. CFSE-labeled PBMCs from allergic and nonatopic subjects were stimulated with RGP extracts (RGPEs) and analyzed for cytokine secretion and T-cell responses. High LPS RGPE increased IFN-γ(+) Th1 and IL-4(+) Th2 effector cell induction and consistently decreased CD4(+) Foxp3(hi) Treg-cell induction. IL-10-producing T-cell frequency was unaltered, but IL-10 secretion was increased by high LPS RGPE. RGPE-stimulation of TLR-transfected cell lines revealed that high LPS pollen also contained a TLR2-ligand, and both batches a TLR9-ligand. Beta-1,3-glucans were detected in large and small MW fractions and were also T-cell stimulatory. In conclusion, coexposure to allergen and proinflammatory microbial stimuli does not convert an established Th2- into a Th1-response. Instead, proinflammatory responses are exacerbated and Foxp3(hi) Treg-cell induction is decreased. These findings show that adjuvants for specific immunotherapy should enhance Treg cells rather than target immune deviation from Th2 to Th1. PMID:23238878

  8. Feeding strategies for groundwater enhanced biodenitrification in an alluvial aquifer: Chemical, microbial and isotope assessment of a 1D flow-through experiment

    Energy Technology Data Exchange (ETDEWEB)

    Vidal-Gavilan, G., E-mail: georginavidal@biorem.cat [D D' ENGINY BIOREM S.L., Madrazo 68, bxs., 08006 Barcelona (Spain); Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristallografia, Mineralogia i Dipòsits MInerals, Universitat de Barcelona, Martí i Franquès s/n, 08028 Barcelona (Spain); Carrey, R., E-mail: rcarrey@ub.edu [Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristallografia, Mineralogia i Dipòsits MInerals, Universitat de Barcelona, Martí i Franquès s/n, 08028 Barcelona (Spain); Solanas, A., E-mail: asolanas@ub.edu [Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Avgda. Diagonal 645, 08028 Barcelona (Spain); Soler, A., E-mail: albertsolergil@ub.edu [Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristallografia, Mineralogia i Dipòsits MInerals, Universitat de Barcelona, Martí i Franquès s/n, 08028 Barcelona (Spain)

    2014-10-01

    Nitrate-removal through enhanced in situ biodenitrification (EISB) is an existing alternative for the recovery of groundwater quality, and is often suggested for use in exploitation wells pumping at small flow-rates. Innovative approaches focus on wider-scale applications, coupling EISB with water-management practices and new monitoring tools. However, before this approach can be used, some water-quality issues such as the accumulation of denitrification intermediates and/or of reduced compounds from other anaerobic processes must be addressed. With such a goal, a flow-through experiment using 100 mg-nitrate/L groundwater was built to simulate an EISB for an alluvial aquifer. Heterotrophic denitrification was induced through the periodic addition of a C source (ethanol), with four different C addition strategies being evaluated to improve the quality of the denitrified water. Chemical, microbial and isotope analyses of the water were performed. Biodenitrification was successfully stimulated by the daily addition of ethanol, easily achieving drinking water standards for both nitrate and nitrite, and showing an expected linear trend for nitrogen and oxygen isotope fractionation, with a εN/εO value of 1.1. Nitrate reduction to ammonium was never detected. Water quality in terms of remaining C, microbial counts, and denitrification intermediates was found to vary with the experimental time, and some secondary microbial respiration processes, mainly manganese reduction, were suspected to occur. Carbon isotope composition from the remaining ethanol also changed, from an initial enrichment in {sup 13}C-ethanol compared to the value of the injected ethanol (− 30.6‰), to a later depletion, achieving δ{sup 13}C values well below the initial isotope composition (to a minimum of − 46.7‰). This depletion in the heavy C isotope follows the trend of an inverse fractionation. Overall, our results indicated that most undesired effects on water quality may be controlled

  9. Feeding strategies for groundwater enhanced biodenitrification in an alluvial aquifer: Chemical, microbial and isotope assessment of a 1D flow-through experiment

    International Nuclear Information System (INIS)

    Nitrate-removal through enhanced in situ biodenitrification (EISB) is an existing alternative for the recovery of groundwater quality, and is often suggested for use in exploitation wells pumping at small flow-rates. Innovative approaches focus on wider-scale applications, coupling EISB with water-management practices and new monitoring tools. However, before this approach can be used, some water-quality issues such as the accumulation of denitrification intermediates and/or of reduced compounds from other anaerobic processes must be addressed. With such a goal, a flow-through experiment using 100 mg-nitrate/L groundwater was built to simulate an EISB for an alluvial aquifer. Heterotrophic denitrification was induced through the periodic addition of a C source (ethanol), with four different C addition strategies being evaluated to improve the quality of the denitrified water. Chemical, microbial and isotope analyses of the water were performed. Biodenitrification was successfully stimulated by the daily addition of ethanol, easily achieving drinking water standards for both nitrate and nitrite, and showing an expected linear trend for nitrogen and oxygen isotope fractionation, with a εN/εO value of 1.1. Nitrate reduction to ammonium was never detected. Water quality in terms of remaining C, microbial counts, and denitrification intermediates was found to vary with the experimental time, and some secondary microbial respiration processes, mainly manganese reduction, were suspected to occur. Carbon isotope composition from the remaining ethanol also changed, from an initial enrichment in 13C-ethanol compared to the value of the injected ethanol (− 30.6‰), to a later depletion, achieving δ13C values well below the initial isotope composition (to a minimum of − 46.7‰). This depletion in the heavy C isotope follows the trend of an inverse fractionation. Overall, our results indicated that most undesired effects on water quality may be controlled through the

  10. Beyond vascularization: aerobic fitness is associated with N-acetylaspartate and working memory.

    Science.gov (United States)

    Erickson, Kirk I; Weinstein, Andrea M; Sutton, Bradley P; Prakash, Ruchika Shaurya; Voss, Michelle W; Chaddock, Laura; Szabo, Amanda N; Mailey, Emily L; White, Siobhan M; Wojcicki, Thomas R; McAuley, Edward; Kramer, Arthur F

    2012-01-01

    Aerobic exercise is a promising form of prevention for cognitive decline; however, little is known about the molecular mechanisms by which exercise and fitness impacts the human brain. Several studies have postulated that increased regional brain volume and function are associated with aerobic fitness because of increased vascularization rather than increased neural tissue per se. We tested this position by examining the relationship between cardiorespiratory fitness and N-acetylaspartate (NAA) levels in the right frontal cortex using magnetic resonance spectroscopy. NAA is a nervous system specific metabolite found predominantly in cell bodies of neurons. We reasoned that if aerobic fitness was predominantly influencing the vasculature of the brain, then NAA levels should not vary as a function of aerobic fitness. However, if aerobic fitness influences the number or viability of neurons, then higher aerobic fitness levels might be associated with greater concentrations of NAA. We examined NAA levels, aerobic fitness, and cognitive performance in 137 older adults without cognitive impairment. Consistent with the latter hypothesis, we found that higher aerobic fitness levels offset an age-related decline in NAA. Furthermore, NAA mediated an association between fitness and backward digit span performance, suggesting that neuronal viability as measured by NAA is important in understanding fitness-related cognitive enhancement. Since NAA is found exclusively in neural tissue, our results indicate that the effect of fitness on the human brain extends beyond vascularization; aerobic fitness is associated with neuronal viability in the frontal cortex of older adults. PMID:22574272

  11. 试论微生物采油技术的研究与应用%Research and application of microbial enhanced oil recovery technology

    Institute of Scientific and Technical Information of China (English)

    陆书峰

    2015-01-01

    Microbial enhanced oil recovery(MEOR)has been developed as the fourth recovery technology followed by thermal, chemical and polymer flooding over the past 100 years. The application of the technology is presented in this paper for guidance.%在近100年的发展里,新兴的热力驱、化学驱、聚合物驱这"三采"技术之后又研发了第四种微生物采油(MEOR)技术,这项技术越来越受到了人们的广泛关注,微生物采油生物工程成为石油工业领域的开拓性应用.本文对其应用进行了阐述以供参考.

  12. A novel aromatic oil compound inhibits microbial overgrowth on feet: a case study

    Directory of Open Access Journals (Sweden)

    Misner Bill D

    2007-07-01

    Full Text Available Abstract Background Athlete's Foot (Tinea pedis is a form of ringworm associated with highly contagious yeast-fungi colonies, although they look like bacteria. Foot bacteria overgrowth produces a harmless pungent odor, however, uncontrolled proliferation of yeast-fungi produces small vesicles, fissures, scaling, and maceration with eroded areas between the toes and the plantar surface of the foot, resulting in intense itching, blisters, and cracking. Painful microbial foot infection may prevent athletic participation. Keeping the feet clean and dry with the toenails trimmed reduces the incidence of skin disease of the feet. Wearing sandals in locker and shower rooms prevents intimate contact with the infecting organisms and alleviates most foot-sensitive infections. Enclosing feet in socks and shoes generates a moisture-rich environment that stimulates overgrowth of pungent both aerobic bacteria and infectious yeast-fungi. Suppression of microbial growth may be accomplished by exposing the feet to air to enhance evaporation to reduce moistures' growth-stimulating effect and is often neglected. There is an association between yeast-fungi overgrowths and disabling foot infections. Potent agents virtually exterminate some microbial growth, but the inevitable presence of infection under the nails predicts future infection. Topical antibiotics present a potent approach with the ideal agent being one that removes moisture producing antibacterial-antifungal activity. Severe infection may require costly prescription drugs, salves, and repeated treatment. Methods A 63-y female volunteered to enclose feet in shoes and socks for 48 hours. Aerobic bacteria and yeast-fungi counts were determined by swab sample incubation technique (1 after 48-hours feet enclosure, (2 after washing feet, and (3 after 8-hours socks-shoes exposure to a aromatic oil powder-compound consisting of arrowroot, baking soda, basil oil, tea tree oil, sage oil, and clove oil. Conclusion

  13. Low-cost step aerobics system with virtual aerobics trainer

    OpenAIRE

    Rosa, Alejandro; Barbancho, Isabel; Tardón, Lorenzo J.; Barbancho, Ana M.

    2014-01-01

    In this paper a low-cost step-aerobics instructor simulation system is presented. The proposed system analyses a given song to iden- tify its rhythmic pattern. Subsequently, this rhythmic pattern is used in order to issue a set of steps-aerobics commands to the user, thus simu- lating a training session. The system uses a Wii Balance Board to track exercises performed by users and runs on an Android smartphone. A set of tests were conducted to assess user experience and opin...

  14. A model for microbial phosphorus cycling in bioturbated marine sediments: Significance for phosphorus burial in the early Paleozoic

    Science.gov (United States)

    Dale, Andrew W.; Boyle, Richard A.; Lenton, Timothy M.; Ingall, Ellery D.; Wallmann, Klaus

    2016-09-01

    A diagenetic model is used to simulate the diagenesis and burial of particulate organic carbon (Corg) and phosphorus (P) in marine sediments underlying anoxic versus oxic bottom waters. The latter are physically mixed by animals moving through the surface sediment (bioturbation) and ventilated by burrowing, tube-dwelling organisms (bioirrigation). The model is constrained using an empirical database including burial ratios of Corg with respect to organic P (Corg:Porg) and total reactive P (Corg:Preac), burial efficiencies of Corg and Porg, and inorganic carbon-to-phosphorus regeneration ratios. If Porg is preferentially mineralized relative to Corg during aerobic respiration, as many previous studies suggest, then the simulated Porg pool is found to be completely depleted. A modified model that incorporates the redox-dependent microbial synthesis of polyphosphates and Porg (termed the microbial P pump) allows preferential mineralization of the bulk Porg pool relative to Corg during both aerobic and anaerobic respiration and is consistent with the database. Results with this model show that P burial is strongly enhanced in sediments hosting fauna. Animals mix highly labile Porg away from the aerobic sediment layers where mineralization rates are highest, thereby mitigating diffusive PO43- fluxes to the bottom water. They also expand the redox niche where microbial P uptake occurs. The model was applied to a hypothetical shelf setting in the early Paleozoic; a time of the first radiation of benthic fauna. Results show that even shallow bioturbation at that time may have had a significant impact on P burial. Our model provides support for a recent study that proposed that faunal radiation in ocean sediments led to enhanced P burial and, possibly, a stabilization of atmospheric O2 levels. The results also help to explain Corg:Porg ratios in the geological record and the persistence of Porg in ancient marine sediments.

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

    OpenAIRE

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

    2014-01-01

    Prior studies have demonstrated that a single session of aerobic exercise can enhance cognitive functioning; specifically, the inhibition facet of executive function (EF). Additionally, previous research has demonstrated that inhibitory abilities are essential for effective dietary self-control. However, it is currently unknown whether exercise induced enhancements in EF also facilitate self-control in the dietary domain. The present study sought to determine whether a single session of aerob...

  16. Effect of short-time aerobic digestion on bioflocculation of extracellular polymeric substances from waste activated sludge.

    Science.gov (United States)

    Zhang, Zhiqiang; Zhang, Jiao; Zhao, Jianfu; Xia, Siqing

    2015-02-01

    The effect of short-time aerobic digestion on bioflocculation of extracellular polymeric substances (EPSs) from waste activated sludge (WAS) was investigated. Bioflocculation of the EPS was found to be enhanced by 2∼6 h of WAS aerobic digestion under the conditions of natural sludge pH (about 7), high sludge concentration by gravity thickening, and dissolved oxygen of about 2 mg/L. With the same EPS extraction method, the total suspended solid content reduction of 0.20 and 0.36 g/L and the volatile suspended solid content reduction of 0.19 and 0.26 g/L were found for the WAS samples before and after aerobic digestion of 4 h. It indicates that more EPS is produced by short-time aerobic digestion of WAS. The scanning electron microscopy images of the WAS samples before and after aerobic digestion of 4 h showed that more EPS appeared on the surface of zoogloea by aerobic digestion, which reconfirmed that WAS aerobic digestion induced abundant formation of EPS. By WAS aerobic digestion, the flocculating rate of the EPS showed about 31 % growth, almost consistent with the growth of its yield (about 34 %). The EPSs obtained before and after the aerobic digestion presented nearly the same components, structures, and Fourier transform infrared spectra. These results revealed that short-time aerobic digestion of WAS enhanced the flocculation of the EPS by promoting its production. PMID:23771440

  17. Anaerobic-Aerobic Process for Microbial Degradation of Tetrabromobisphenol A

    OpenAIRE

    Ronen, Zeev; Abeliovich, Aharon

    2000-01-01

    Tetrabromobisphenol A (TBBPA) is a flame retardant that is used as an additive during manufacturing of plastic polymers and electronic circuit boards. Little is known about the fate of this compound in the environment. In the current study we investigated biodegradation of TBBPA, as well as 2,4,6-tribromophenol (TBP), in slurry of anaerobic sediment from a wet ephemeral desert stream bed contaminated with chemical industry waste. Anaerobic incubation of the sediment with TBBPA and peptone-try...

  18. Enhanced response of microbial fuel cell using sulfonated poly ether ether ketone membrane as a biochemical oxygen demand sensor

    Energy Technology Data Exchange (ETDEWEB)

    Ayyaru, Sivasankaran; Dharmalingam, Sangeetha, E-mail: sangeetha@annauniv.edu

    2014-03-01

    Graphical abstract: - Highlights: • Sulfonated poly ether ether ketone (SPEEK) membrane in SCMFC used to determine the BOD. • The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm. • This sensing range was 62.5% higher than that of Nafion{sup ®}. • SPEEK exhibited one order lesser oxygen permeability than Nafion{sup ®}. • Nafion{sup ®} shows high anodic internal resistance (67 Ω) than the SPEEK (39 Ω). - Abstract: The present study is focused on the development of single chamber microbial fuel cell (SCMFC) using sulfonated poly ether ether ketone (SPEEK) membrane to determine the biochemical oxygen demand (BOD) matter present in artificial wastewater (AW). The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm when using artificial wastewater. This sensing range was 62.5% higher than that of Nafion{sup ®}. The most serious problem in using MFC as a BOD sensor is the oxygen diffusion into the anode compartment, which consumes electrons in the anode compartment, thereby reducing the coulomb yield and reducing the electrical signal from the MFC. SPEEK exhibited one order lesser oxygen permeability than Nafion{sup ®}, resulting in low internal resistance and substrate loss, thus improving the sensing range of BOD. The system was further improved by making a double membrane electrode assembly (MEA) with an increased electrode surface area which provide high surface area for electrically active bacteria.

  19. Development of low cost ceramic separator using mineral cation exchanger to enhance performance of microbial fuel cells

    International Nuclear Information System (INIS)

    This study deals with the development of ceramic separator (CS) made from red soil blended with cation exchanger, Montmorillonite and Kaolinite, for its application in microbial fuel cells (MFCs). The separators were characterized in terms of conductivity, oxygen, acetate and proton diffusion, and ion transport ability. Performance of MFCs using different CS was evaluated under batch mode of operation. MFC M-20 (CS blended with 20% Montmorillonite) exhibited maximum power density of 7.5 W/m3 which was 48% higher than MFC without exchanger (Control) and 30%, 9%, 27% higher than MFC M-10 (10% Montmorillonite), MFC M-15 (15% Montmorillonite), MFC K-20 (20% Kaolinite), respectively. Coulombic efficiency of MFC M-20 (30%) and MFC K-20 (23%) was higher compared to control (18%). Use of cation exchangers improved properties of ceramic separators compared to control. Higher cation exchange capacity (CEC) of Montmorillonite (150 meq/100 g) resulted in 4 fold decrease in charge transfer resistance (3.4 Ω) and 1.8 fold increase in conductivity (5.56 × 10−4 S/cm) of CS as compared to Kaolinite. This study demonstrates that Montmorillonite incorporated CS proved to be suitable alternative to replace costly polymeric membrane to increase power output of MFC at reduced cost

  20. Team-Based Learning Enhances Long-Term Retention and Critical Thinking in an Undergraduate Microbial Physiology Course

    Directory of Open Access Journals (Sweden)

    L. Dee Fink

    2003-12-01

    Full Text Available We used team-based learning to improve comprehension and critical thinking of students in an undergraduate microbial metabolism-physiology course. The course used well-known bacterial pathways to highlight themes of energy conservation and biodegradation. Prior to the introduction of team-based learning, student recall of this information was poor and students had difficulty extrapolating information to new organisms. Initially, individual and group quizzes were added to promote problem-solving and critical-thinking skills. This significantly improved student attitudes about the amount of information they learned and whether the instructor promoted critical thinking. However, retention of the material as judged by final examination scores was still poor. In the next year, two challenging projects were added to the course to complement the above themes: (i postulating a pathway for the metabolism of a substrate by a bacterium, and (ii modifying the current model for anaerobic sulfate reduction by incorporating recent genetic information. The inclusion of the team projects significantly improved final examination scores compared to the previous year without team projects. Overall, team-based learning with challenging projects improved the students’ comprehension and retention of information, critical thinking, and attitudes about the course and focused student-instructor interactions on learning rather than grades.

  1. Team-Based Learning Enhances Long-Term Retention and Critical Thinking in an Undergraduate Microbial Physiology Course

    Directory of Open Access Journals (Sweden)

    Michael J. McInerney

    2009-12-01

    Full Text Available We used team-based learning to improve comprehension and critical thinking of students in an undergraduate microbial metabolism-physiology course. The course used well-known bacterial pathways to highlight themes of energy conservation and biodegradation. Prior to the introduction of team-based learning, student recall of this information was poor and students had difficulty extrapolating information to new organisms. Initially, individual and group quizzes were added to promote problem-solving and critical-thinking skills. This significantly improved student attitudes about the amount of information they learned and whether the instructor promoted critical thinking. However, retention of the material as judged by final examination scores was still poor. In the next year, two challenging projects were added to the course to complement the above themes: (i postulating a pathway for the metabolism of a substrate by a bacterium, and (ii modifying the current model for anaerobic sulfate reduction by incorporating recent genetic information. The inclusion of the team projects significantly improved final examination scores compared to the previous year without team projects. Overall, team-based learning with challenging projects improved the students’ comprehension and retention of information, critical thinking, and attitudes about the course and focused student-instructor interactions on learning rather than grades.

  2. Enhanced response of microbial fuel cell using sulfonated poly ether ether ketone membrane as a biochemical oxygen demand sensor

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Sulfonated poly ether ether ketone (SPEEK) membrane in SCMFC used to determine the BOD. • The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm. • This sensing range was 62.5% higher than that of Nafion®. • SPEEK exhibited one order lesser oxygen permeability than Nafion®. • Nafion® shows high anodic internal resistance (67 Ω) than the SPEEK (39 Ω). - Abstract: The present study is focused on the development of single chamber microbial fuel cell (SCMFC) using sulfonated poly ether ether ketone (SPEEK) membrane to determine the biochemical oxygen demand (BOD) matter present in artificial wastewater (AW). The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm when using artificial wastewater. This sensing range was 62.5% higher than that of Nafion®. The most serious problem in using MFC as a BOD sensor is the oxygen diffusion into the anode compartment, which consumes electrons in the anode compartment, thereby reducing the coulomb yield and reducing the electrical signal from the MFC. SPEEK exhibited one order lesser oxygen permeability than Nafion®, resulting in low internal resistance and substrate loss, thus improving the sensing range of BOD. The system was further improved by making a double membrane electrode assembly (MEA) with an increased electrode surface area which provide high surface area for electrically active bacteria

  3. Aerobic exercise in pulmonary rehabilitation

    Directory of Open Access Journals (Sweden)

    Thiago Brasileiro de Vasconcelos

    2013-01-01

    Full Text Available The aim of this study was to conduct a literature review on the usefulness of aerobic exercise in pulmonary rehabilitation. This is an exploratory study of literature through the electronic databases Medline, Lilacs, Scielo, Pubmed and Google Scholar, published between 1996 and 2012, conducted during the period February to May 2012 with the following keywords: COPD, pulmonary rehabilitation, aerobic exercises, physical training, quality of life. The change in pulmonary function and dysfunction of skeletal muscles that result in exercise intolerance and reduced fitness and may cause social isolation, depression, anxiety and addiction. The training exercise is the most important component of the program of pulmonary rehabilitation where the aerobic training provides consistent results in clinical improvement in levels of exercise tolerance and decreased dyspnea generating more benefits to the body, reducing the chance of cardiovascular disease and improves quality and expectation of life. We demonstrated that the use of aerobic exercise in pulmonary rehabilitation program, allows an improvement of motor skills, decreased muscle fatigue and deconditioning, reducing sedentary lifestyle; however, has little or no effect on the reduction of strength and atrophy muscle.

  4. Enhancement of volatile fatty acid production by co-fermentation of food waste and excess sludge without pH control: The mechanism and microbial community analyses.

    Science.gov (United States)

    Wu, Qing-Lian; Guo, Wan-Qian; Zheng, He-Shan; Luo, Hai-Chao; Feng, Xiao-Chi; Yin, Ren-Li; Ren, Nan-Qi

    2016-09-01

    The study provided a cost-effective and high-efficiency volatile fatty acid (VFA) production strategy by co-fermentation of food waste (FW) and excess sludge (ES) without artificial pH control. VFA production of 867.42mg COD/g-VS was obtained under the optimized condition: FW/ES 5, solid retention time 7d, organic loading rate 9g VS/L-d and temperature 40°C. Mechanism exploration revealed that the holistic biodegradability of substrate was greatly enhanced, and proper pH range (5.2-6.4) was formed by the high buffering capacity of the co-fermentation system itself, which effectively enhanced hydrolysis yield (63.04%) and acidification yield (83.46%) and inhibited methanogenesis. Moreover, microbial community analysis manifested that co-fermentation raised the relative abundances of hydrolytic and acidogenic bacteria including Clostridium, Sporanaerobacter, Tissierella and Bacillus, but suppressed the methanogen Anaerolineae, which also facilitated high VFA production. These results were of great guiding significance aiming for VFA recovery from FW and ES in large-scale. PMID:27289056

  5. Overexpressing Ferredoxins in Chlamydomonas reinhardtii Increase Starch and Oil Yields and Enhance Electric Power Production in a Photo Microbial Fuel Cell

    Directory of Open Access Journals (Sweden)

    Li-Fen Huang

    2015-08-01

    Full Text Available Ferredoxins (FDX are final electron carrier proteins in the plant photosynthetic pathway, and function as major electron donors in diverse redox-driven metabolic pathways. We previously showed that overexpression of a major constitutively expressed ferredoxin gene PETF in Chlamydomonas decreased the reactive oxygen species (ROS level and enhanced tolerance to heat stress. In addition to PETF, an endogenous anaerobic induced FDX5 was overexpressed in transgenic Chlamydomonas lines here to address the possible functions of FDX5. All the independent FDX transgenic lines showed decreased cellular ROS levels and enhanced tolerance to heat and salt stresses. The transgenic Chlamydomonas lines accumulated more starch than the wild-type line and this effect increased almost three-fold in conditions of nitrogen depletion. Furthermore, the lipid content was higher in the transgenic lines than in the wild-type line, both with and without nitrogen depletion. Two FDX-overexpressing Chlamydomonas lines were assessed in a photo microbial fuel cell (PMFC; power density production by the transgenic lines was higher than that of the wild-type cells. These findings suggest that overexpression of either PETF or FDX5 can confer tolerance against heat and salt stresses, increase starch and oil production, and raise electric power density in a PMFC.

  6. Reviews Related to the Techniques of Enhancing Microbial Stress Resistance%提高微生物抗逆性技术的研究进展

    Institute of Scientific and Technical Information of China (English)

    刘玉萍; 唐鸿志; 许平

    2014-01-01

    Various stress resistant genes or mechanisms presented in microorganisms, and the discovery of these mechanisms laid a sound foundation for the directional enhancement of microbial stress tolerance. The main techniques of enhancing stress resistance of microorganisms contain over expression of stress-resistant genes, long-term adaptive evolution, genome shuffling, and heterologous expression of stress-resistant genes. These biological techniques can efficiently improve the stress resistance of industrial and environmental microorganisms, which surely benefited the bacteria based on industrial production and degradation of environmental pollutants.%微生物体内存在多种抗逆基因或机制,这些机制的发现为定向提高微生物的抗逆性奠定了基础。提高微生物抗逆性的技术主要有过表达抗逆基因,长期适应性进化, genome shuffling(基因组改组)和异源表达抗逆基因等。利用这几种技术增强微生物的抗逆性,在以微生物为主的工业生产和环境污染物降解方面有着广阔的应用前景。

  7. Microbial response to nitrate treatment in offshore oil fields

    Energy Technology Data Exchange (ETDEWEB)

    Boedtker, Gunhild

    2009-07-01

    phosphate and nitrate to stimulate growth of aerobic oil-degrading bacteria with the purpose of microbial enhanced oil recovery (MEOR). Nitrate also serves as souring control. The results from molecular analysis (filterPCR-DGGE) of produced water from Norne showed that bacteria affiliated to mesophilic, aerobic and facultative anaerobic bacteria able to use nitrate as alternative electron acceptor represented the major bacterial groups constituting 13% and 27%, respectively, of the phylotypes observed. Among these were bacteria affiliated to hydrocarbon-degrading Alcanivorax, Marinobacter, Dietzia, Acinetobacter, Novosphingobium, Planomicrobium and Microbacterium. Reduction in oil-water interfacial tension (IFT) during bacterial growth on water-immiscible hydrocarbons is one of the mechanisms believed to mobilize oil during MEOR. We assessed the potential for IFT reduction during growth of hydrocarbon-degrading Dietzia sp. A14101 at an oil-water interface by applying advanced laser-light scattering technique. The results showed an exponential reduction in IFT from 38 mN/m to a minimum level of 0.006 mN/m. A reduction in IFT of this magnitude is sufficient to cause mobilization of entrapped reservoir oil. Dietzia sp. A14101 was observed to utilize a range of hydrocarbons during aerobic growth and fatty acids during anaerobic growth with nitrate as electron acceptor. This suggests a potential double role of Dietzia in oil reservoirs where aerobic MEOR is combined with nitrate treatment. Overall, the results from the current study are in accordance with the biofilm model and recent biostat theory, which place the majority of microbial activity in water flooded oil reservoirs in the cooled area near injectors. Our results show that this activity may be manipulated and controlled by injecting mineral nutrients and alternative electron acceptors. However, due to the different characters of the world's oil reservoirs and the varying quality of injection water, further

  8. The biocathode of microbial electrochemical systems and microbially-influenced corrosion.

    Science.gov (United States)

    Kim, Byung Hong; Lim, Swee Su; Daud, Wan Ramli Wan; Gadd, Geoffrey Michael; Chang, In Seop

    2015-08-01

    The cathode reaction is one of the most important limiting factors in bioelectrochemical systems even with precious metal catalysts. Since aerobic bacteria have a much higher affinity for oxygen than any known abiotic cathode catalysts, the performance of a microbial fuel cell can be improved through the use of electrochemically-active oxygen-reducing bacteria acting as the cathode catalyst. These consume electrons available from the electrode to reduce the electron acceptors present, probably conserving energy for growth. Anaerobic bacteria reduce protons to hydrogen in microbial electrolysis cells (MECs). These aerobic and anaerobic bacterial activities resemble those catalyzing microbially-influenced corrosion (MIC). Sulfate-reducing bacteria and homoacetogens have been identified in MEC biocathodes. For sustainable operation, microbes in a biocathode should conserve energy during such electron-consuming reactions probably by similar mechanisms as those occurring in MIC. A novel hypothesis is proposed here which explains how energy can be conserved by microbes in MEC biocathodes. PMID:25976915

  9. Nitrobenzene biodegradation ability of microbial communities in water and sediments along Songhua River after a nitrobenzene pollution event

    Institute of Scientific and Technical Information of China (English)

    LI Zonglai; YANG Min; LI Dong; QI Rong; LIU Huijuan; SUN Jingfang; QU Jiuhui

    2008-01-01

    More than 100 t of nitrobenzene (NB) and related compounds were discharged into the Songhua River, the fourth longest river in China, because of the world-shaking explosion of an aniline production factory located in Jilin City on November 13, 2005. As one of the efforts to predict the fate of residual NB in the river, NB biodegradation abilities of the microbes in the water and sediments from different river sections were evaluated systematically. The results indicated that microbial communities from any section of the river, including one section at the upper stream of the NB discharging point, had the ability to biodegrade NB under aerobic (for river water samples) conditions at 22±1℃ or anaerobic (for sediment samples) conditions at 10±1℃. NB degradation rates of microbial communities in the downstream sites were markedly higher than those in the upstream site, indicating that the NB degradation abilities were enhanced because of the pollution of NB. Aerobic degradation got neglected at a temperature of 10℃ or lower. The production of nitrosobenzene and aniline during the aerobic biodegradation suggested the existence of at least two different NB degradation pathways, and the occurrence of the catechol-2,3-dioxygenase (C23O) gene and the significant decrease of dissolved organic carbon (DOC) indicated that NB could be mineralized under aerobic conditions. Although it was a fact that the river have frozen-up during the NB accident, it was speculated that biodegradation was not the major process responsible for the decrease of NB flux in the river.

  10. Bifunctional Ag/Fe/N/C Catalysts for Enhancing Oxygen Reduction via Cathodic Biofilm Inhibition in Microbial Fuel Cells.

    Science.gov (United States)

    Dai, Ying; Chan, Yingzi; Jiang, Baojiang; Wang, Lei; Zou, Jinlong; Pan, Kai; Fu, Honggang

    2016-03-23

    Limitation of the oxygen reduction reaction (ORR) in single-chamber microbial fuel cells (SC-MFCs) is considered an important hurdle in achieving their practical application. The cathodic catalysts faced with a liquid phase are easily primed with the electrolyte, which provides more surface area for bacterial overgrowth, resulting in the difficulty in transporting protons to active sites. Ag/Fe/N/C composites prepared from Ag and Fe-chelated melamine are used as antibacterial ORR catalysts for SC-MFCs. The structure-activity correlations for Ag/Fe/N/C are investigated by tuning the carbonization temperature (600-900 °C) to clarify how the active-constituents of Ag/Fe and N-species influence the antibacterial and ORR activities. A maximum power density of 1791 mW m(-2) is obtained by Ag/Fe/N/C (630 °C), which is far higher than that of Pt/C (1192 mW m(-2)), only having a decline of 16.14% after 90 days of running. The Fe-bonded N and the cooperation of pyridinic N and pyrrolic N in Ag/Fe/N/C contribute equally to the highly catalytic activity toward ORR. The ·OH or O2(-) species originating from the catalysis of O2 can suppress the biofilm growth on Ag/Fe/N/C cathodes. The synergistic effects between the Ag/Fe heterojunction and N-species substantially contribute to the high power output and Coulombic efficiency of Ag/Fe/N/C catalysts. These new antibacterial ORR catalysts show promise for application in MFCs. PMID:26938657

  11. Enhanced hydrogen production from waste activated sludge by cascade utilization of organic matter in microbial electrolysis cells.

    Science.gov (United States)

    Lu, Lu; Xing, Defeng; Liu, Bingfeng; Ren, Nanqi

    2012-03-15

    Fermentative hydrogen production from waste activated sludge (WAS) has low H2 yield because WAS contains limited amounts of carbohydrate suitable for use by hydrogen-producing bacteria. Here, augmentation of hydrogen production from WAS by microbial electrolysis cells (MECs) was implemented. H2 yields of 3.89±0.39 mg-H2/g-DS (5.67±0.61 mg-H2/g-VSS) from raw WAS and 6.78±0.94 mg-H2/g-DS (15.08±1.41 mg-H2/g-VSS) from alkaline-pretreated WAS were obtained in the two-chamber MECs (TMECs). This was several times higher than yields obtained previously by fermentation. Single-chamber MECs (SMECs) with low internal resistance showed a H2 production rate that 13 times that of TMECs with similar H2 yield when alkaline-pretreated WAS was used. However, methanogenesis was detected after several batch cycles. A yield balance calculation revealed that carbohydrates were not the only substrates for electrohydrogenesis. Protein and its acidification products, such as volatile fatty acids are also responsible for a portion of H2 generation in MEC. Characterization of WAS in TMECs by three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy with parallel factor analysis indicated that electrohydrogenesis reacted on the extracellular polymeric substances and intracellular substances of WAS. Cascade utilization of organic matter in MECs increased hydrogen production from WAS. MECs showed high hydrogen yield from WAS, fewer H2 sinks, and insensitivity to temperature. Optimizing MEC configurations and operation conditions and improving the pretreatment processes of WAS are necessary before practical application can take place on a large scale. PMID:22197264

  12. Stimulated Growth of Aerobic Microbes Using Calcium Peroxide

    Institute of Scientific and Technical Information of China (English)

    LIU Shejiang; LI Mujin; JIANG Bin; LI Xingang

    2006-01-01

    With continuous and slow oxygen-release characteristic,calcium peroxide (CaO2) has been a new source of supplying oxygen for aerobic microbes in bioremediation of contaminated groundwater.Batch experiments were conducted to evaluate the oxygen-release rate of CaO2 reacting with water,the regulation of high pH,as well as the growth of mixed aerobic microbes in the medium containing CaO2.The results show that the oxygen-release process of CaO2 comprises three phases.In the first phase,dissolved oxygen levels of water increased sharply,and average oxygen-release rates increased as the adding weight of CaO2 increased.However,the rates almost ly.As the necessary components of medium,potassium dihydrogen phosphate (KH2PO4) and ammonium sulphate ((NH4)2SO4) at a certain ratio could regulate pH caused by CaO2 from 12.1 to the range of 6.5-8.5,which is helpful for microbial growth.In addition,diauxic growth curve observed in the medium containing CaO2 suggested that the growth of mixed aerobic microbes could be stimulated by the addition of CaO2.

  13. Tundra soil carbon is vulnerable to rapid microbial decomposition under climate warming

    Science.gov (United States)

    Xue, Kai; M. Yuan, Mengting; J. Shi, Zhou; Qin, Yujia; Deng, Ye; Cheng, Lei; Wu, Liyou; He, Zhili; van Nostrand, Joy D.; Bracho, Rosvel; Natali, Susan; Schuur, Edward. A. G.; Luo, Chengwei; Konstantinidis, Konstantinos T.; Wang, Qiong; Cole, James R.; Tiedje, James M.; Luo, Yiqi; Zhou, Jizhong

    2016-06-01

    Microbial decomposition of soil carbon in high-latitude tundra underlain with permafrost is one of the most important, but poorly understood, potential positive feedbacks of greenhouse gas emissions from terrestrial ecosystems into the atmosphere in a warmer world. Using integrated metagenomic technologies, we showed that the microbial functional community structure in the active layer of tundra soil was significantly altered after only 1.5 years of warming, a rapid response demonstrating the high sensitivity of this ecosystem to warming. The abundances of microbial functional genes involved in both aerobic and anaerobic carbon decomposition were also markedly increased by this short-term warming. Consistent with this, ecosystem respiration (Reco) increased up to 38%. In addition, warming enhanced genes involved in nutrient cycling, which very likely contributed to an observed increase (30%) in gross primary productivity (GPP). However, the GPP increase did not offset the extra Reco, resulting in significantly more net carbon loss in warmed plots compared with control plots. Altogether, our results demonstrate the vulnerability of active-layer soil carbon in this permafrost-based tundra ecosystem to climate warming and the importance of microbial communities in mediating such vulnerability.

  14. Insights into microbial communities in suboxic and anoxic parts of the Dagang oilfield

    Science.gov (United States)

    Yao, Jun; Richnow, Hans

    2015-04-01

    The overall target of this research is to understand the ecology of facultative and anaerobic bacterial communities related to hydrocarbon degradation in a part of the Dagang oilfield. In the oilfield since many years large amounts of water and surfactants are injected for oil extraction. This mode of oil production will likely affect the microbial community structure in the semi-open recycling system. In the production water, aerobic and facultative anaerobic bacteria are abundant, but their ecological function in the reservoir is still not understood. For microbial enhanced oil recovery (MEOR) however, it is important to understand the role of these microbial communities in the reservoir. For characterising the microbial community, the abundances of bacteria, archaea, sulfate reducing bacteria (SRB) and methanogenic Archaea were measured by real-time quantitative PCR in both injection and oil water, meanwhile the functional gene P450 involved aerobic degradation was also determined using common PCR with specific primers. In this study, it found that injection well1095 has a higher abundance of bacteria, archaea, dsr A and mcr A than those in most of production water, suggesting that a majority of bacteria not growth in the reservoir. Furthermore, on the basis of functional gene measurement aerobic and anaerobic microorganisms were living together in the extreme oil reservoirs. In contrast, the percentage of dsr A to bacteria and mcr A to archaea in production well exceeds the number in most of production wells. These results indicate that some indigenous bacteria such as SRB and methanogen can adjust them to reservoir environments. Methanogenic Archaea are widespread in the anaerobic environment and play an important role in the terminal steps of organic matter degradation to form methane, while SRB are capable of mineralizing petroleum components. The analysis of the production water reveals that concentration of SO42- and NO3- in injection water is lower than

  15. Enhanced waste activated sludge digestion using a submerged anaerobic dynamic membrane bioreactor: performance, sludge characteristics and microbial community

    Science.gov (United States)

    Yu, Hongguang; Wang, Zhiwei; Wu, Zhichao; Zhu, Chaowei

    2016-02-01

    Anaerobic digestion (AD) plays an important role in waste activated sludge (WAS) treatment; however, conventional AD (CAD) process needs substantial improvements, especially for the treatment of WAS with low solids content and poor anaerobic biodegradability. Herein, we propose a submerged anaerobic dynamic membrane bioreactor (AnDMBR) for simultaneous WAS thickening and digestion without any pretreatment. During the long-term operation, the AnDMBR exhibited an enhanced sludge reduction and improved methane production over CAD process. Moreover, the biogas generated in the AnDMBR contained higher methane content than CAD process. Stable carbon isotopic signatures elucidated the occurrence of combined methanogenic pathways in the AnDMBR process, in which hydrogenotrophic methanogenic pathway made a larger contribution to the total methane production. It was also found that organic matter degradation was enhanced in the AnDMBR, thus providing more favorable substrates for microorganisms. Pyrosequencing revealed that Proteobacteria and Bacteroidetes were abundant in bacterial communities and Methanosarcina and Methanosaeta in archaeal communities, which played an important role in the AnDMBR system. This study shed light on the enhanced digestion of WAS using AnDMBR technology.

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

    OpenAIRE

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

    2007-01-01

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

  17. Characterization of microorganisms responsible for phosphorus removal linking operation performance with microbial community structure at low temperature.

    Science.gov (United States)

    Zou, Haiming; Lu, Xiwu; Saad, Abualhail

    2014-01-01

    Two enhanced biological phosphorus removal (EBPR) reactors were started up at low temperatures to obtain microorganisms responsible for aerobic and anoxic phosphorus removal, namely polyphosphate-accumulating organisms (PAO) and denitrifying PAO (DPAO), and their operational performance and microbial community were together investigated in the hope of assessment of the effectiveness of the EBPR process at low temperature by combining chemical analysis and microbial community structure evolution based on polymerase chain reaction-denaturing gradient gel electrophoresis. When two reactors reached the steady state after 40 and 80 days for the anaerobic-aerobic (AO) and anaerobic-anoxic (AA) reactor operation in AO and AA modes, respectively, a good ability of anaerobic phosphorus release and aerobic or anoxic phosphorus uptake was present both in these two reactors. During this start-up process, a total of 22 bands were detected in seed, AA and AO sludge samples, including Alpha-, Beta-, Gamma- and Deltaproteobacteria, as well as Chlorobi, Firmicutes, Bacteroidetes and Actinobacteria. Of all the bands, only four bands were present in all the lanes, suggesting that shift in microbial community occurred greatly depending on the electron acceptors in this study. From evolutionary tree, it was found that microorganisms related to DPAO mostly belong to the phylum Betaproteobacteria, while microbes corresponding to PAO were present in several phyla. Overall, the new strategy proposed here was shown to be feasible for the enrichment of PAO and DPAO at low temperature, and may be regarded as a new guidance for the application of EBPR technology to practice, especially in winter. PMID:24701905

  18. Microbial Consortia Development and Microcosm and Column Experiments for Enhanced Bioremediation of Chlorinated Volatile Organic Compounds, West Branch Canal Creek Wetland Area, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Lorah, Michelle M.; Majcher, Emily H.; Jones, Elizabeth J.; Voytek, Mary A.

    2008-01-01

    Chlorinated solvents, including 1,1,2,2-tetrachloroethane, tetrachloroethene, trichloroethene, carbon tetrachloride, and chloroform, are reaching land surface in localized areas of focused ground-water discharge (seeps) in a wetland and tidal creek in the West Branch Canal Creek area, Aberdeen Proving Ground, Maryland. In cooperation with the U.S. Army Garrison, Aberdeen Proving Ground, Maryland, the U.S. Geological Survey is developing enhanced bioremediation methods that simulate the natural anaerobic degradation that occurs without intervention in non-seep areas of the wetland. A combination of natural attenuation and enhanced bioremediation could provide a remedy for the discharging ground-water plumes that would minimize disturbance to the sensitive wetland ecosystem. Biostimulation (addition of organic substrate or nutrients) and bioaugmentation (addition of microbial consortium), applied either by direct injection at depth in the wetland sediments or by construction of a permeable reactive mat at the seep surface, were tested as possible methods to enhance anaerobic degradation in the seep areas. For the first phase of developing enhanced bioremediation methods for the contaminant mixtures in the seeps, laboratory studies were conducted to develop a microbial consortium to degrade 1,1,2,2-tetrachloroethane and its chlorinated daughter products under anaerobic conditions, and to test biostimulation and bioaugmentation of wetland sediment and reactive mat matrices in microcosms. The individual components required for the direct injection and reactive mat methods were then combined in column experiments to test them under groundwater- flow rates and contaminant concentrations observed in the field. Results showed that both direct injection and the reactive mat are promising remediation methods, although the success of direct injection likely would depend on adequately distributing and maintaining organic substrate throughout the wetland sediment in the seep

  19. Promoting Motor Cortical Plasticity with Acute Aerobic Exercise: A Role for Cerebellar Circuits

    Science.gov (United States)

    Mang, Cameron S.; Brown, Katlyn E.; Neva, Jason L.; Snow, Nicholas J.; Campbell, Kristin L.; Boyd, Lara A.

    2016-01-01

    Acute aerobic exercise facilitated long-term potentiation-like plasticity in the human primary motor cortex (M1). Here, we investigated the effect of acute aerobic exercise on cerebellar circuits, and their potential contribution to altered M1 plasticity in healthy individuals (age: 24.8 ± 4.1 years). In Experiment   1, acute aerobic exercise reduced cerebellar inhibition (CBI) (n = 10, p = 0.01), elicited by dual-coil paired-pulse transcranial magnetic stimulation. In Experiment   2, we evaluated the facilitatory effects of aerobic exercise on responses to paired associative stimulation, delivered with a 25 ms (PAS25) or 21 ms (PAS21) interstimulus interval (n = 16 per group). Increased M1 excitability evoked by PAS25, but not PAS21, relies on trans-cerebellar sensory pathways. The magnitude of the aerobic exercise effect on PAS response was not significantly different between PAS protocols (interaction effect: p = 0.30); however, planned comparisons indicated that, relative to a period of rest, acute aerobic exercise enhanced the excitatory response to PAS25 (p = 0.02), but not PAS21 (p = 0.30). Thus, the results of these planned comparisons indirectly provide modest evidence that modulation of cerebellar circuits may contribute to exercise-induced increases in M1 plasticity. The findings have implications for developing aerobic exercise strategies to “prime” M1 plasticity for enhanced motor skill learning in applied settings.

  20. Enhancement of microbial diversity and methane yield by bacterial bioaugmentation through the anaerobic digestion of Haematococcus pluvialis.

    Science.gov (United States)

    Aydin, Sevcan

    2016-06-01

    Microalgae has recalcitrant cell walls that may limit digestibility and, therefore, reduce bioenergy production. In light of the fact that cellulose can increase the cell wall recalcitrance of the Haematococcus pluvialis species of microalgae, the objective of this research was to examine how bioaugmentation with the Clostridium thermocellum at various inoculum ratios represents a viable method by which the CH4 production of microalgae can be enhanced. The results of the investigation revealed that bioaugmentation with C. thermocellum increased the degradation of H. pluvialis biomass and resulted in a 18-38 % increase in methane production as a result of increased cell disruption. In addition, the use of Illumina Miseq sequencing highlighted that the bacterial and archaeal diversity and quantities in the genus were enhanced as a result of the addition of C. thermocellum and this, in itself, improved the efficiency of the biodegradation. Bioaugmentation with C. thermocellum (%15) was also determined to represent the most energy-efficiency method of producing methane. PMID:27067588

  1. Integration of pneumatic fracturing with bioremediation from the enhanced removal of BTX from low permeability gasoline-contaminated soils

    International Nuclear Information System (INIS)

    A pilot-scale evaluation of the integrated pneumatic fracturing and bioremediation system was carried out to demonstrate the enhanced removal of BTX from a gasoline contaminated, low permeability soil formation. The fracturing enhanced subsurface permeability by an average of over 36 times, and established an extended bioremediation zone supporting aerobic, denitrifying and methanogenic populations. Subsurface amendment injections consisting of phosphate and nitrogen were made periodically over a 50-week period to stimulate microbial activity. Results indicate that 79% of the soil-phase BTX was removed during the field test, with over 85% of the mass removed attributable to bioremediation

  2. The Andersen aerobic fitness test

    DEFF Research Database (Denmark)

    Aadland, Eivind; Terum, Torkil; Mamen, Asgeir;

    2014-01-01

    BACKGROUND: High aerobic fitness is consistently associated with a favorable metabolic risk profile in children. Direct measurement of peak oxygen consumption (VO2peak) is often not feasible, thus indirect tests such as the Andersen test are required in many settings. The present study seeks to...... agreement) were 26.7±125.2 m for test 2 vs. test 1 (p<.001 for mean difference) and 3.9±88.8 m for test 3 vs. test 2 (p = .514 for mean difference). The equation to estimate VO2peak suggested by Andersen et al. (2008) showed a poor fit in the present sample; thus, we suggest a new equation: VO2peak = 23....... Researchers should be aware of the amount of noise in indirect tests that estimate aerobic fitness....

  3. Antioxidant Enhancement of Some Arabic Date Varieties by Using Gamma Irradiation in Reference to Microbial Infection During Storage

    International Nuclear Information System (INIS)

    Three semi-dry date varieties from Egypt (Siwi), Saudi Arabia (Sukkary) and Iraq (Zahdi) at tamrstage were irradiated with safety low doses (3 and 5 kGy), as alternative for pesticides, for decontamination of molds and consequently improving the quality for human consumption. Gamma irradiated samples were analyzed for antioxidants (AA) mainly flavonoids and phenolic compounds and also for microbiological and mycotoxin contents. The detection of fungi revealed the presence of seven species of pathogenic fungi with high levels in non-irradiated dates such as Fusarium spp., Aspergillus parasiticus, A. flavus, A. niger, Penicillium spp., Cladosporium spp. and Mucor spp. Siwi variety (Egyptian) was contaminated more than Sukkary (Saudi Arabian). Gamma irradiation was more affecting in decontamination of molds in most samples especially at 5 kGy. Also, the presence of aflatoxins (AFT) resulted as B1, B2 and OTA in Egyptian dates (Siwi) while in contrary, some AFT were absent in Sukkary (Saudi Arabian). The results proved that AFT concentration of tested samples was less than the recommended dose (20 ppb) as reduced by gamma irradiation dose (5 kGy). HPLC analysis of AA (falvonoids and phenols) in three date verities proved the presence of 15 compounds such as quarctin, ferulic, caffeic, salicylic, eugonal, chatechol, chrysic, gallic, pyrogallic, protochechol, eugonol, syrining, rutinol, phenol and cumaric. The concentration of AA (mg/100 g) depends on variety. The enhancement % by irradiation was more clear with Sukkary (Saudi Arabian) than Siwi (Egyptian) or Zahdi (Iraqi). AA were enhanced strongly by irradiation dose of 5 kGy in all contents and the increase in AA concentration in date fruits decreased the growth of fungi counts or excretion of aflatoxins in selected samples of Siwi and Sukkary varieties. The increase in AA goes in parallel with the decrease in tannins content of most varieties during storage for 4 or 8 months. It could be concluded that using gamma

  4. Bioremediation of 1,2-dichloroethane contaminated groundwater: Microcosm and microbial diversity studies

    International Nuclear Information System (INIS)

    In this study, the effectiveness of bioremediating 1,2-dichloroethane (DCA)-contaminated groundwater under different oxidation–reduction processes was evaluated. Microcosms were constructed using indigenous bacteria and activated sludge as the inocula and cane molasses and a slow polycolloid-releasing substrate (SPRS) as the primary substrates. Complete DCA removal was obtained within 30 days under aerobic and reductive dechlorinating conditions. In anaerobic microcosms with sludge and substrate addition, chloroethane, vinyl chloride, and ethene were produced. The microbial communities and DCA-degrading bacteria in microcosms were characterized by 16S rRNA-based denatured-gradient-gel electrophoresis profiling and nucleotide sequence analyses. Real-time polymerase chain reaction was applied to evaluate the variations in Dehalococcoides spp. and Desulfitobacterium spp. Increase in Desulfitobacterium spp. indicates that the growth of Desulfitobacterium might be induced by DCA. Results indicate that DCA could be used as the primary substrate under aerobic conditions. The increased ethene concentrations imply that dihaloelimination was the dominate mechanism for DCA biodegradation. - Highlights: • DCA can be used as the primary substrate and degraded by the indigenous microbial consortia. • Reductive dechlorination of DCA can be enhanced by the supplement of substrates and sludge. • Dihaloelimination is the dominant mechanism for DCA dechlorination and ethene is the end product. • SPRS can serve as the primary substrate and creates anaerobic conditions for DCA dechlorination. • Reductive dechlorination is a feasible option for DCA-contaminated groundwater remediation. - DCA can serve as the primary substrate and degraded by indigenous bacteria aerobically. Dihaloelimination is the dominant mechanism and ethene is the end product via dechlorination

  5. Construction and evaluation of an exopolysaccharide-producing engineered bacterial strain by protoplast fusion for microbial enhanced oil recovery.

    Science.gov (United States)

    Sun, Shanshan; Luo, Yijing; Cao, Siyuan; Li, Wenhong; Zhang, Zhongzhi; Jiang, Lingxi; Dong, Hanping; Yu, Li; Wu, Wei-Min

    2013-09-01

    Enterobacter cloacae strain JD, which produces water-insoluble biopolymers at optimal temperature of 30°C, and a thermophilic Geobacillus strain were used to construct an engineered strain for exopolysaccharide production at high temperatures by protoplast fusion. The obtained fusant strain ZR3 produced exopolysaccharides at up to 45°C with optimal growth temperature at 35°C. The fusant produced exopolysaccharides of approximately 7.5 g/L or more at pH between 7.0 and 9.0. The feasibility of the enhancement of crude oil recovery with the fusant was tested in a sand-packed column at 40°C. The results demonstrated that bioaugmentation of the fusant was promising approach for MEOR. Mass growth of the fusant was confirmed in fermentor tests. PMID:23856587

  6. The adjuvant activity of alphavirus replicons is enhanced by incorporating the microbial molecule flagellin into the replicon.

    Directory of Open Access Journals (Sweden)

    Maria L Knudsen

    Full Text Available Ligands of pattern recognition receptors (PRRs including Toll-like receptors (TLRs stimulate innate and adaptive immune responses and are considered as potent adjuvants. Combinations of ligands might act in synergy to induce stronger and broader immune responses compared to stand-alone ligands. Alphaviruses stimulate endosomal TLRs 3, 7 and 8 as well as the cytoplasmic PRR MDA-5, resulting in induction of a strong type I interferon (IFN response. Bacterial flagellin stimulates TLR5 and when delivered intracellularly the cytosolic PRR NLRC4, leading to secretion of proinflammatory cytokines. Both alphaviruses and flagellin have independently been shown to act as adjuvants for antigen-specific antibody responses. Here, we hypothesized that alphavirus and flagellin would act in synergy when combined. We therefore cloned the Salmonella Typhimurium flagellin (FliC gene into an alphavirus replicon and assessed its adjuvant activity on the antibody response against co-administered antigen. In mice immunized with recombinant alphavirus, antibody responses were greatly enhanced compared to soluble FliC or control alphavirus. Both IgG1 and IgG2a/c responses were increased, indicating an enhancement of both Th1 and Th2 type responses. The adjuvant activity of FliC-expressing alphavirus was diminished but not abolished in the absence of TLR5 or type I IFN signaling, suggesting the contribution of several signaling pathways and some synergistic and redundant activity of its components. Thus, we have created a recombinant adjuvant that stimulates multiple signaling pathways of innate immunity resulting in a strong and broad antibody response.

  7. Enhanced methane production in an anaerobic digestion and microbial electrolysis cell coupled system with co-cultivation of Geobacter and Methanosarcina.

    Science.gov (United States)

    Yin, Qi; Zhu, Xiaoyu; Zhan, Guoqiang; Bo, Tao; Yang, Yanfei; Tao, Yong; He, Xiaohong; Li, Daping; Yan, Zhiying

    2016-04-01

    The anaerobic digestion (AD) and microbial electrolysis cell (MEC) coupled system has been proved to be a promising process for biomethane production. In this paper, it was found that by co-cultivating Geobacter with Methanosarcina in an AD-MEC coupled system, methane yield was further increased by 24.1%, achieving to 360.2mL/g-COD, which was comparable to the theoretical methane yield of an anaerobic digester. With the presence of Geobacter, the maximum chemical oxygen demand (COD) removal rate (216.8mg COD/(L·hr)) and current density (304.3A/m(3)) were both increased by 1.3 and 1.8 fold compared to the previous study without Geobacter, resulting in overall energy efficiency reaching up to 74.6%. Community analysis demonstrated that Geobacter and Methanosarcina could coexist together in the biofilm, and the electrochemical activities of both were confirmed by cyclic voltammetry. Our study observed that the carbon dioxide content in total gas generated from the AD reactor with Geobacter was only half of that generated from the same reactor without Geobacter, suggesting that Methanosarcina may obtain the electron transferred from Geobacter for the reduction of carbon dioxide to methane. Taken together, Geobacter not only can improve the performance of the MEC system, but also can enhance methane production. PMID:27090713

  8. Enhanced Oxygen and Hydroxide Transport in a Cathode Interface by Efficient Antibacterial Property of a Silver Nanoparticle-Modified, Activated Carbon Cathode in Microbial Fuel Cells.

    Science.gov (United States)

    Li, Da; Qu, Youpeng; Liu, Jia; Liu, Guohong; Zhang, Jie; Feng, Yujie

    2016-08-17

    A biofilm growing on an air cathode is responsible for the decreased performance of microbial fuel cells (MFCs). For the undesired biofilm to be minimized, silver nanoparticles were synthesized on activated carbon as the cathodic catalyst (Ag/AC) in MFCs. Ag/AC enhanced maximum power density by 14.6% compared to that of a bare activated carbon cathode (AC) due to the additional silver catalysis. After operating MFCs over five months, protein content on the Ag/AC cathode was only 38.3% of that on the AC cathode, which resulted in a higher oxygen concentration diffusing through the Ag/AC cathode. In addition, a lower pH increment (0.2 units) was obtained near the Ag/AC catalyst surface after biofouling compared to 0.8 units of the AC cathode, indicating that less biofilm on the Ag/AC cathode had a minor resistance on hydroxide transported from the catalyst layer interfaces to the bulk solution. Therefore, less decrements of the Ag/AC activity and MFC performance were obtained. This result indicated that accelerated transport of oxygen and hydroxide, benefitting from the antibacterial property of the cathode, could efficiently maintain higher cathode stability during long-term operation. PMID:27441786

  9. Poly(vinylidene fluoride-co-hexafluoropropylene) phase inversion coating as a diffusion layer to enhance the cathode performance in microbial fuel cells

    KAUST Repository

    Yang, Wulin

    2014-12-01

    A low cost poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) phase inversion coating was developed as a cathode diffusion layer to enhance the performance of microbial fuel cells (MFCs). A maximum power density of 1430 ± 90 mW m-2 was achieved at a PVDF-HFP loading of 4.4 mg cm-2 (4:1 polymer:carbon black), with activated carbon as the oxygen reduction cathode catalyst. This power density was 31% higher than that obtained with a more conventional platinum (Pt) catalyst on carbon cloth (Pt/C) cathode with a poly(tetrafluoroethylene) (PTFE) diffusion layer (1090 ± 30 mW m-2). The improved performance was due in part to a larger oxygen mass transfer coefficient of 3 × 10-3 cm s-1 for the PVDF-HFP coated cathode, compared to 1.7 × 10-3 cm s -1 for the carbon cloth/PTFE-based cathode. The diffusion layer was resistant to electrolyte leakage up to water column heights of 41 ± 0.5 cm (4.4 mg cm-2 loading of 4:1 polymer:carbon black) to 70 ± 5 cm (8.8 mg cm-2 loading of 4:1 polymer:carbon black). This new type of PVDF-HFP/carbon black diffusion layer could reduce the cost of manufacturing cathodes for MFCs. © 2014 Elsevier B.V. All rights reserved.

  10. Enhanced power production of a membrane electrode assembly microbial fuel cell (MFC) using a cost effective poly [2,5-benzimidazole] (ABPBI) impregnated non-woven fabric filter.

    Science.gov (United States)

    Choi, Soojung; Kim, Jung Rae; Cha, Jaehwan; Kim, Yejin; Premier, Giuliano C; Kim, Changwon

    2013-01-01

    A membrane electrode assembly (MEA) microbial fuel cell (MFC) with a non-woven paper fabric filter (NWF) was investigated as an alternative to a proton exchange membrane (PEM) separator. The MFC with a NWF generated a cell voltage of 545 mV and a maximum power density of 1027 mW/m(3), which was comparable to that obtained from MFCs with a PEM (551 mV, 609 mW/m(3)). The MFC with a NWF showed stable cell performance (550 mV) over 300 days, whereas, the MFC with PEM performance decreased significantly from 551 mV to 415 mV due to biofilm formation and chemical precipitation on the membrane surface. Poly [2,5-benzimidazole] (ABPBI) was evaluated with respect to its capacity to increased proton conductivity and contact between separator and electrodes. The overall performance of the MFC with ABPBI was improved by enhancing the ion conductivity and steric contact, producing 766 mW/m(3) at optimum loading of 50 mg ABPBI/cm(2). PMID:23196216

  11. Microbial Methane Oxidation Rates in Guandu Wetland of northern Taiwan

    Science.gov (United States)

    Yu, Zih-Huei; Wang, Pei-Ling; Lin, Li-Hung

    2016-04-01

    Wetland is one of the major sources of atmospheric methane. The exact magnitude of methane emission is essentially controlled by microbial processes. Besides of methanogenesis, methanotrophy oxidizes methane with the reduction of various electron acceptors under oxic or anoxic conditions. The interplay of these microbial activities determines the final methane flux under different circumstances. In a tidal wetland, the cyclic flooding and recession of tide render oxygen and sulfate the dominant electron acceptors for methane oxidation. However, the details have not been fully examined, especially for the linkage between potential methane oxidation rates and in situ condition. In this study, a sub-tropical wetland in northern Taiwan, Guandu, was chosen to examine the tidal effect on microbial methane regulation. Several sediment cores were retrieved during high tide and low tide period and their geochemical profiles were characterized to demonstrate in situ microbial activities. Incubation experiments were conducted to estimate potential aerobic and anaerobic methane oxidation rates in surface and core sediments. Sediment cores collected in high tide and low tide period showed different geochemical characteristics, owning to tidal inundation. Chloride and sulfate concentration were lower during low tide period. A spike of enhanced sulfate at middle depth intervals was sandwiched by two sulfate depleted zones above and underneath. Methane was accumulated significantly with two methane depletion zones nearly mirroring the sulfate spike zone identified. During the high tide period, sulfate decreased slightly with depth with methane production inhibited at shallow depths. However, a methane consumption zone still occurred near the surface. Potential aerobic methane oxidation rates were estimated between 0.7 to 1.1 μmole/g/d, showing no difference between the samples collected at high tide or low tide period. However, a lag phase was widely observed and the lag phase

  12. Sonified Aerobics - Interactive Sonification of coordinated body movements

    OpenAIRE

    Hermann, Thomas; Zehe, Sebastian; Worall, David; Wersényi, György

    2011-01-01

    This paper introduces a new hard-/ and software system for the interactive sonification of sports movement involving arm- and leg movements. Two different sonifications are designed to convey rhythmical patterns that become auditory gestalt so that listeners can identify features of the underlying coordinated movement. The Sonification is designed for the application to enable visually impaired users to participate in aerobics exercises, and also to enhance the perception of movements for sig...

  13. Global study of microbial communites in tilipia gut fed sludge-infused diets

    Science.gov (United States)

    The goal of this project was to examine the impact of microbial diversity in feed on gut communities of fish. To do so, tilapia larvae were fed three experimental diets incorporated with sludge produced under either aerobic, methanogenic or denitrifying conditions. Microbial diversity between differ...

  14. The effect of aerobic exercise on autonomic function and pain in women with fibromyalgia.

    OpenAIRE

    Brandsarbakken, Håvard

    2010-01-01

    Fibromyalgia (FM) is a chronic pain syndrome often accompanied by an autonomic dysfunction. Reduced heart rate variability (HRV) indicating an enhanced sympathetic drive at rest and a lack of sympathetic reactivity during stress is commonly seen in subjects with FM. Earlier studies have shown that aerobic exercise can increase HRV in healthy persons. The aim of this study was to use recordings of HRV and blood pressure (BP) in the evaluation of the effects of a moderate intensity aerobic exer...

  15. Microbial Degradation of Organic Wastes at Low Temperatures.

    Directory of Open Access Journals (Sweden)

    K.V. Ramana

    2000-10-01

    Full Text Available Microbial degradation of organic wastes mainly comprising animal and human wastes, is drastically reduced at extreme low temperatures. For the biodegradation of these wastes, technological inputs are required from disciplines like microbiology, biochemistry, molecular biology, digester modelling and heat transfer at extreme low temperature climates. Various steps in the process of biodegradation have to be studied to formulate an effective organic waste disposal method. Anaerobic digestion of organic wastes is preferred over aerobic waste treatment method, since it yields biogas as a by-product, which in turn can be utilised for heating the digester contents to increase its efficiency. Furthermore, one of the possibilities that can be explored is the utilisation of high rate anaerobic digesters which maintain temperature by means of artificial heating. It is either met by non-conventional energy sources, such as solar and wind energy, or by expending liquid fuels. In addition, insulation of the digester with polymeric materials and immobilisation of slow growing bacterial population may enhance the digester performance to a great extent. In spite of several developments, inoculum adaptation is considered to be one of the essential steps for low temperature anaerobic digestion to obtain methane as a by-product. With advancements in recombinant DNA technology, it may be possible to increase the efficiency of various microbial population that take part in the anaerobic digestion. However, till date, the options available for low temperature biodegradation are digester insulation, inoculum adaptation, and use of high rate/second-generation digesters.

  16. Biological degradation of triclocarban and triclosan in a soil under aerobic and anaerobic conditions and comparison with environmental fate modelling

    International Nuclear Information System (INIS)

    Triclocarban and triclosan are two antimicrobial agents widely used in many personal care products. Their biodegradation behaviour in soil was investigated by laboratory degradation experiments and environmental fate modelling. Quantitative structure-activity relationship (QSAR) analyses showed that triclocarban and triclosan had a tendency to partition into soil or sediment in the environment. Fate modelling suggests that either triclocarban or triclosan 'does not degrade fast' with its primary biodegradation half-life of 'weeks' and ultimate biodegradation half-life of 'months'. Laboratory experiments showed that triclocarban and triclosan were degraded in the aerobic soil with half-life of 108 days and 18 days, respectively. No negative effect of these two antimicrobial agents on soil microbial activity was observed in the aerobic soil samples during the experiments. But these two compounds persisted in the anaerobic soil within 70 days of the experimental period. - Triclocarban and triclosan can be degraded by microbial processes in aerobic soil, but will persist in anaerobic soil

  17. Methods to determine aerobic endurance.

    Science.gov (United States)

    Bosquet, Laurent; Léger, Luc; Legros, Patrick

    2002-01-01

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

  18. Aerobic biodegradation of organic compounds in hydraulic fracturing fluids.

    Science.gov (United States)

    Kekacs, Daniel; Drollette, Brian D; Brooker, Michael; Plata, Desiree L; Mouser, Paula J

    2015-07-01

    Little is known of the attenuation of chemical mixtures created for hydraulic fracturing within the natural environment. A synthetic hydraulic fracturing fluid was developed from disclosed industry formulas and produced for laboratory experiments using commercial additives in use by Marcellus shale field crews. The experiments employed an internationally accepted standard method (OECD 301A) to evaluate aerobic biodegradation potential of the fluid mixture by monitoring the removal of dissolved organic carbon (DOC) from an aqueous solution by activated sludge and lake water microbial consortia for two substrate concentrations and four salinities. Microbial degradation removed from 57 % to more than 90 % of added DOC within 6.5 days, with higher removal efficiency at more dilute concentrations and little difference in overall removal extent between sludge and lake microbe treatments. The alcohols isopropanol and octanol were degraded to levels below detection limits while the solvent acetone accumulated in biological treatments through time. Salinity concentrations of 40 g/L or more completely inhibited degradation during the first 6.5 days of incubation with the synthetic hydraulic fracturing fluid even though communities were pre-acclimated to salt. Initially diverse microbial communities became dominated by 16S rRNA sequences affiliated with Pseudomonas and other Pseudomonadaceae after incubation with the synthetic fracturing fluid, taxa which may be involved in acetone production. These data expand our understanding of constraints on the biodegradation potential of organic compounds in hydraulic fracturing fluids under aerobic conditions in the event that they are accidentally released to surface waters and shallow soils. PMID:26037076

  19. Methyl-β-cyclodextrin enhanced biodegradation of polycyclic aromatic hydrocarbons and associated microbial activity in contaminated soil

    Institute of Scientific and Technical Information of China (English)

    Mingming Sun; Yongming Luo; Peter Christie; Zhongjun Jia; Zhengao Li; Ying Teng

    2012-01-01

    The contamination of soils by polycyclic aromatic hydrocarbons (PAHs) is a widespread environmental problem and the remediation of PAHs from these areas has been a major concern.The effectiveness of many in situ bioremediation systems may be constrained by low contaminant bipavailability due to limited aqueous solubility or a large magnitude of sorption.The objective of this research was to evaluate the effect of methyl-β-cyclodextrin (MCD) on bioaugmentation by Paracoccus sp.strain HPD-2 of an aged PAH-contaminated soil.When 10% (W/W) MCD amendment was combined with bioaugmentation by the PAH-degrading bacterium Paracoccus sp.strain HPD-2,the percentage degradation of total PAHs was significantly enhanced up to 34.8%.Higher counts of culturable PAH-degrading bacteria and higher soil dehydrogenase and soil polyphenol oxidase activities were observed in 10% (W/W) MCD-assisted bioaugmentation soil.This MCD-assisted bioaugmentation strategy showed significant increases (p < 0.05) in the average well color development (AWCD) obtained by the BIOLOG Eco plate assay,Shannon-Weaver index (H) and Simpson index (λ) compared with the controls,implying that this strategy at least partially restored the microbiological functioning of the PAH-contaminated soil.The results suggest that MCD-aided bioaugmentation by Paracoccus sp.strain HPD-2 may be a promising practical bioremediation strategy for aged PAH-contaminated soils.

  20. Enhancement of electricity production in a mediatorless air-cathode microbial fuel cell using Klebsiella sp. IR21.

    Science.gov (United States)

    Lee, Yun-Yeong; Kim, Tae Gwan; Cho, Kyung-Suk

    2016-06-01

    A novel dissimilatory iron-reducing bacteria, Klebsiella sp. IR21, was isolated from the anode biofilm of an MFC reactor. Klebsiella sp. IR21 reduced 27.8 % of ferric iron to ferrous iron demonstrating that Klebsiella sp. IR21 has electron transfer ability. Additionally, Klebsiella sp. IR21 generated electricity forming a biofilm on the anode surface. When a pure culture of Klebsiella sp. IR21 was supplied into a single chamber, air-cathode MFC fed with a mixture of glucose and acetate (500 mg L(-1) COD), 40-60 mV of voltage (17-26 mA m(-2) of current density) was produced. Klebsiella sp. IR21 was also utilized as a biocatalyst to improve the electrical performance of a conventional MFC reactor. A single chamber, air-cathode MFC was fed with reject wastewater (10,000 mg L(-1) COD) from a H2 fermentation reactor. The average voltage, current density, and power density were 142.9 ± 25.74 mV, 60.5 ± 11.61 mA m(-2), and 8.9 ± 3.65 mW m(-2), respectively, in the MFC without inoculation of Klebsiella sp. IR21. However, these electrical performances of the MFC were significantly increased to 204.7 ± 40.24 mV, 87.5 ± 17.20 mA m(-2), and 18.6 ± 7.23 mW m(-2), respectively, with inoculation of Klebsiella sp. IR21. The results indicate that Klebsiella sp. IR21 can be utilized as a biocatalyst for enhancement of electrical performance in MFC systems. PMID:26956141

  1. Aerobic treatment of winery wastewater with the aim of water reuse

    OpenAIRE

    M. de OLIVEIRA; Queda, C.; Duarte, E.

    2009-01-01

    An air micro-bubble bioreactor (AMBB) using a free self-adapted microbial population, 15dm3 working volume, was used for aerobic treatment of winery wastewater. This reactor utilizes a Venturi injector in conjunction with mass transfer multiplier nozzles, which allow an efficient oxygen transfer. The reactor can operate in batch or continuous conditions. The dynamics of chemical oxygen demand (COD), biomass and total contents of polyphenolic compounds was followed throughout ea...

  2. The photosynthetic apparatus and its regulation in the aerobic gammaproteobacterium Congregibacter litoralis gen. nov., sp. nov.

    OpenAIRE

    Spring, Stefan; Lünsdorf, Heinrich; Fuchs, Bernhard M.; Tindall, Brian J.

    2009-01-01

    BACKGROUND: There is accumulating evidence that in some marine environments aerobic bacteriochlorophyll a-producing bacteria represent a significant part of the microbial population. The interaction of photosynthesis and carbon metabolism in these interesting bacteria is still largely unknown and requires further investigation in order to estimate their contribution to the marine carbon cycle. METHODOLOGY/PRINCIPAL FINDINGS: Here, we analyzed the structure, composition and regulation of the p...

  3. Influence of different substrates on the formation and characteristics of aerobic granules in sequencing batch reactors

    Institute of Scientific and Technical Information of China (English)

    SUN Fei-yun; YANG Cheng-yong; LI Jiu-yi; YANG Ya-jing

    2006-01-01

    The effects of different substrates on the aerobic granulation process were studied using laboratory-scale sequencing batch reactors (SBRs). Four parallel granules sequencing batch reactors (GSBR): R1, R2, R3, and R4 were fed with acetate, glucose, peptone and fecula, respectively. Stable aerobic granules were successfully cultivated in R1, R2, R4, and smaller granules less than 500 μm were formed in R3. Morphology and the physic-chemical characteristics of aerobic granules fed with different carbon substrates were investigated by the four reactors operated under the same pressure. The aerobic granules in the four reactors were observed and found that peptone was the most stable one due to its good settleability even after a sludge age as short as l0 d. A strong correlation was testified between the characteristics of aerobic granules and the properties of carbon substrates. The stability of aerobic granules was affected by extracellular polymer substances (EPS) derived from microorganism growth during feast time fed with different carbon substrates, and the influence of the property of storage substance was greater than that of its quantity. Optimal carbon substrates, which are helpful in the cultivation and retention of well-settling granules and in the enhancement of the overall ability of the aerobic granules reactors, were found.

  4. Towards a microbial thermoelectric cell.

    Science.gov (United States)

    Rodríguez-Barreiro, Raúl; Abendroth, Christian; Vilanova, Cristina; Moya, Andrés; Porcar, Manuel

    2013-01-01

    Microbial growth is an exothermic process. Biotechnological industries produce large amounts of heat, usually considered an undesirable by-product. In this work, we report the construction and characterization of the first microbial thermoelectric cell (MTC), in which the metabolic heat produced by a thermally insulated microbial culture is partially converted into electricity through a thermoelectric device optimized for low ΔT values. A temperature of 41°C and net electric voltage of around 250-600 mV was achieved with 1.7 L baker's yeast culture. This is the first time microbial metabolic energy has been converted into electricity with an ad hoc thermoelectric device. These results might contribute towards developing a novel strategy to harvest excess heat in the biotechnology industry, in processes such as ethanol fermentation, auto thermal aerobic digestion (ATAD) or bioremediation, which could be coupled with MTCs in a single unit to produce electricity as a valuable by-product of the primary biotechnological product. Additionally, we propose that small portable MTCs could be conceived and inoculated with suitable thermophilic of hyperthermophilic starter cultures and used for powering small electric devices. PMID:23468862

  5. Towards a microbial thermoelectric cell.

    Directory of Open Access Journals (Sweden)

    Raúl Rodríguez-Barreiro

    Full Text Available Microbial growth is an exothermic process. Biotechnological industries produce large amounts of heat, usually considered an undesirable by-product. In this work, we report the construction and characterization of the first microbial thermoelectric cell (MTC, in which the metabolic heat produced by a thermally insulated microbial culture is partially converted into electricity through a thermoelectric device optimized for low ΔT values. A temperature of 41°C and net electric voltage of around 250-600 mV was achieved with 1.7 L baker's yeast culture. This is the first time microbial metabolic energy has been converted into electricity with an ad hoc thermoelectric device. These results might contribute towards developing a novel strategy to harvest excess heat in the biotechnology industry, in processes such as ethanol fermentation, auto thermal aerobic digestion (ATAD or bioremediation, which could be coupled with MTCs in a single unit to produce electricity as a valuable by-product of the primary biotechnological product. Additionally, we propose that small portable MTCs could be conceived and inoculated with suitable thermophilic of hyperthermophilic starter cultures and used for powering small electric devices.

  6. Microbiology and potential applications of aerobic methane oxidation coupled to denitrification (AME-D) process: A review.

    Science.gov (United States)

    Zhu, Jing; Wang, Qian; Yuan, Mengdong; Tan, Giin-Yu Amy; Sun, Faqian; Wang, Cheng; Wu, Weixiang; Lee, Po-Heng

    2016-03-01

    Aerobic methane oxidation coupled to denitrification (AME-D) is an important link between the global methane and nitrogen cycles. This mini-review updates discoveries regarding aerobic methanotrophs and denitrifiers, as a prelude to spotlight the microbial mechanism and the potential applications of AME-D. Until recently, AME-D was thought to be accomplished by a microbial consortium where denitrifying bacteria utilize carbon intermediates, which are excreted by aerobic methanotrophs, as energy and carbon sources. Potential carbon intermediates include methanol, citrate and acetate. This mini-review presents microbial thermodynamic estimations and postulates that methanol is the ideal electron donor for denitrification, and may serve as a trophic link between methanotrophic bacteria and denitrifiers. More excitingly, new discoveries have revealed that AME-D is not only confined to the conventional synergism between methanotrophic bacteria and denitrifiers. Specifically, an obligate aerobic methanotrophic bacterium, Methylomonas denitrificans FJG1, has been demonstrated to couple partial denitrification with methane oxidation, under hypoxia conditions, releasing nitrous oxide as a terminal product. This finding not only substantially advances the understanding of AME-D mechanism, but also implies an important but unknown role of aerobic methanotrophs in global climate change through their influence on both the methane and nitrogen cycles in ecosystems. Hence, further investigation on AME-D microbiology and mechanism is essential to better understand global climate issues and to develop niche biotechnological solutions. This mini-review also presents traditional microbial techniques, such as pure cultivation and stable isotope probing, and powerful microbial techniques, such as (meta-) genomics and (meta-) transcriptomics, for deciphering linked methane oxidation and denitrification. Although AME-D has immense potential for nitrogen removal from wastewater, drinking

  7. Investigation on behavior of bacteria in reservoir for microbial enhanced oil recovery; Biseibutsuho (MEOR) no tameno yusonai saikin katsudo ni kansuru chosa

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, K.; Tanaka, S.; Otsuka, M.; Nakaya, K. [Kansai Research Institute, Kyoto (Japan). Lifescience Research Center; Maezumi, S.; Yazawa, N. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center; Hong, C.; Chida, T.; Enomoto, H. [Tohoku University, Miyagi (Japan). Graduate School of Engineering

    2000-07-01

    Behavior of bacteria activated in reservoir though molasses-injection-tests, was investigated using the restriction fragment length polymorphism analysis with the polymerase chain reaction (PCR-RFLP) method, for elucidating potential bacteria to suppress in situ growth of microbes to be injected into the reservoir in the microbial enhanced oil recovery (MEOR) process. As a result, some bacteria belonging to Enterobacteriaceae species or their close relative species were grown predominantly in the reservoir, among bacteria inhibiting in the ground-water. The foregoing indicates that behavior of these bacteria in reservoir must be taken into consideration when giving a full account of behavior of microbes to be injected into the reservoir to put the MEOR process into operation. Potential proliferation using molasses to activate those bacteria was also estimated on the laboratory tests, to clarify the growth of microbes to be injected into the reservoir to operate the MEOR process. In consequence, it became clear that these bacteria have a potential growth exceeding 10{sup 8} CFU/ml, utilizing molasses. These facts indicated that microbes to be injected into the reservoir at the MEOR field tests are necessary to grow more excellently than bacteria inhabiting in the ground-water. In addition, as flow, the injection fluid is influenced by reservoir heterogeneity caused by injection of molasses, it was inferred that microbes to be injected into the reservoir at the MEOR field process are also necessary to grow more remarkably than bacteria inhabiting in the reservoir brine at high permeability zones and bacteria inhabiting in the reservoir rock. Furthermore, the results of the functional testing for MEOR conducted in the presence of bacteria activated through molasses-injection-tests indicated the importance of effective use of microbes to be injected, taking into account the characteristics of the reservoir and function for MEOR of those microbes. (author)

  8. Enhancing Management Tools: Molecular Genetic Tracking to Target Microbial Pollution Sources in South Florida Coral Reefs, Year 1 - CRCP project #1114

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Both coastal inlets and treated wastewater outfalls are recognized as major pathways for microbial contaminants from Land-Based Sources of Pollution (LBSP) to enter...

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

    Science.gov (United States)

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

    2016-04-01

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

  10. Improving aerobic stability and biogas production of maize silage using silage additives.

    Science.gov (United States)

    Herrmann, Christiane; Idler, Christine; Heiermann, Monika

    2015-12-01

    The effects of air stress during storage, exposure to air at feed-out, and treatment with silage additives to enhance aerobic stability on methane production from maize silage were investigated at laboratory scale. Up to 17% of the methane potential of maize without additive was lost during seven days exposure to air on feed-out. Air stress during storage reduced aerobic stability and further increased methane losses. A chemical additive containing salts of benzoate and propionate, and inoculants containing heterofermentative lactic acid bacteria were effective to increase aerobic stability and resulted in up to 29% higher methane yields after exposure to air. Exclusion of air to the best possible extent and high aerobic stabilities should be primary objectives when ensiling biogas feedstocks. PMID:26348286

  11. Aerobic rice mechanization: techniques for crop establishment

    Science.gov (United States)

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

    2015-12-01

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

  12. Aerobic Dancing--A Rhythmic Sport.

    Science.gov (United States)

    Sorensen, Jacki

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

  13. Skeletal Muscle Hypertrophy after Aerobic Exercise Training

    OpenAIRE

    Konopka, Adam R.; Harber, Matthew P.

    2014-01-01

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

  14. Aerobic growth at nanomolar oxygen concentrations

    DEFF Research Database (Denmark)

    Stolper, Daniel; Revsbech, Niels Peter; Canfield, Donald Eugene

    2010-01-01

    Escherichia coli K-12, chosen for its well-understood biochemistry, rapid growth rate, and low-oxygen-affinity terminal oxidase, grows at oxygen levels of ≤ 3 nM, two to three orders of magnitude lower than previously observed for aerobes. Our study expands both the environmental range and temporal history of...... aerobic organisms....

  15. Randomized Double-blind Placebo-controlled Clinical Trial and Assessment of Fermentation Product of Cordyceps Sinensis (Cs-4) in Enhancing Aerobic Capacity and Respiratory Function of The Healthy Elderly Volunteers

    Institute of Scientific and Technical Information of China (English)

    肖毅; 黄席珍; 朱佳石

    2004-01-01

    Objective: Cordyceps sinensis (CS) is a popular natural Chinese herbal medicine for invigoration, health preservation and reducing fatigue. Its natural substance has been prepared as a fermentation product of a specific strain of Cordyceps sinensis (Cs-4). Our objective was to assess the effect of Cs-4 on the exercise capacity of the healthy elderly people in a randomized, double-blind, placebo-controlled trial.Methods; Thirty-seven healthy, elderly Chinese subjects were randomly assigned to receive either Cs-4 (3 g/day) or identical placebo capsules. Their exercise performance was tested before and after 6 weeks of treatment with a symptom-limited, incremental work rate protocol on a cycle ergometer. Maximum oxygen uptake (VO2max) was measured using a metabolic chart. Anaerobic thresholds (VO2θ) were identified by two observers using plots of both VCO2 vs VO2 and VE/VO2 vs time. Results: After taking Cs-4 for 6 weeks,VO2max (1. 88±0.13 to 2. 00±0.14 L/min; P=0.050) and VO2θ (1. 15±0.07 to 1. 30±0.09 L/min; P=0. 012) were significantly increased, whereas after placebo application they were unchanged. Conclusion:These findings support the belief held in China that Cs-4 could improve oxygen uptake or aerobic capacity and ventilation function and resistance to fatigue of elderly people in exercise.

  16. Corrosion inhibition of mild steel by aerobic biofilm

    International Nuclear Information System (INIS)

    Mild steel electrodes were incubated in phosphate-buffered basal salt solution (BSS) having two different aerobic bacteria, viz. Pseudomonas alcaligenes and Pseudomonas cichorii. In the medium containing P. cichorii, significant reduction in the corrosion rate was observed due to the surface reaction leading to the formation of corrosion inhibiting bacterial biofilm. With a view to understand the mechanism of microbially influenced corrosion/corrosion inhibition, electrochemical and biological experiments such as electrochemical impedance spectroscopy (EIS) measurements and biochemical analysis were made. The exposed surfaces were examined using scanning electron micrographs (SEM), energy dispersive spectroscopy (EDS) and electron spectroscopy for chemical analysis (ESCA). The scraped surface film was also examined using FT-IR spectroscopy. The results suggested that mild steel surface contained iron oxide-phosphate layer covered with bacteria and exo polymeric substance (EPS)/iron-EPS complex for P. cichorii and iron oxides and iron phosphate for P. alcaligenes

  17. Avaliação de inoculante microbiano na composição bromatológica, fermentação e estabilidade aeróbia da silagem pré-seca de alfafa Evaluation of microbial inoculant on chemical composition, fermentation characteristics and aerobic stability of alfalfa haylage

    Directory of Open Access Journals (Sweden)

    Vanessa Jaime de Almeida Magalhães

    2004-02-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos do inoculante microbiano Silobac® (L. plantarum, P. pentosaceus, na silagem pré-seca de alfafa, em 22 silos, distribuídos em dois tratamentos, sendo 11 silos com inoculante e 11 controle, segundo o delineamento inteiramente casualizado. A alfafa foi cortada quando em estádio do meio do florescimento e os silos, confeccionados com aproximadamente 600 kg e revestidos com película de PVC branca. Amostras foram coletadas, logo após a abertura de cada silo, para análise bromatológica e perfil fermentativo. O inoculante diminuiu o teor de MS (inoculada = 44,7 vs. controle = 51,2% e aumentou a concentração de ácido acético (2,35 vs. 0,89% MS, em relação ao grupo controle. O inoculante também revelou diminuição no escore de bolor obtido a 10 cm de profundidade, mas não a 30 ou 50 cm. Não foram observados efeitos sobre os teores de PB (15,9 vs. 16,4% MS, NIDN (14,7 vs. 16,2% do N total, NIDA (11,2 vs. 11,6% do N total, FDN (47,1 vs. 46,7% MS, FDA (40,2 vs. 39,8% MS, celulose (29,7 vs. 28,6% MS, hemicelulose (6,94 vs. 6,89% MS, LDA (10,4 vs. 11,1% MS, carboidratos solúveis (2,97 vs. 2,44% MS e amido (0,82 vs. 0,69% MS, DIVMS (61,6 vs. 62,5% MS, poder tampão (52,9 vs. 51,7 meq./100g MS, as concentrações de etanol (0,018 vs. 0,024% MS e dos ácidos propiônico (0,00 vs. 0,00% MS, butírico (0,00 vs. 0,00% MS e lático (5,62 vs. 4,45% MS, a relação lático:acético (4,57 vs. 4,87, bem como sobre o pH (4,96 vs. 5,33, as concentrações de N-NH3 (8,19 vs. 5,21% do N total e a estabilidade aeróbia.The objective of this study was to evaluate the effects of microbial inoculant Silobac® (L. plantarum, P. pentosaceus on alfalfa haylage, in twenty-two big bales, allotted to two treatment, eleven with inoculant and eleven control, assigned to a totally randomized design. Alfalfa crop was harvested at middle bloom stage and conditioned in silage bales of about 600 kg capacity and covered with

  18. Aerobic N2O emission for activated sludge acclimated under different aeration rates in the multiple anoxic and aerobic process.

    Science.gov (United States)

    Wang, Huoqing; Guan, Yuntao; Pan, Min; Wu, Guangxue

    2016-05-01

    Nitrous oxide (N2O) is a potent greenhouse gas that can be emitted during biological nitrogen removal. N2O emission was examined in a multiple anoxic and aerobic process at the aeration rates of 600mL/min sequencing batch reactor (SBRL) and 1200mL/min (SBRH). The nitrogen removal percentage was 89% in SBRL and 71% in SBRH, respectively. N2O emission mainly occurred during the aerobic phase, and the N2O emission factor was 10.1% in SBRL and 2.3% in SBRH, respectively. In all batch experiments, the N2O emission potential was high in SBRL compared with SBRH. In SBRL, with increasing aeration rates, the N2O emission factor decreased during nitrification, while it increased during denitrification and simultaneous nitrification and denitrification (SND). By contrast, in SBRH the N2O emission factor during nitrification, denitrification and SND was relatively low and changed little with increasing aeration rates. The microbial competition affected the N2O emission during biological nitrogen removal. PMID:27155411

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

    Science.gov (United States)

    Edvardsen, Elisabeth; Ingjer, Frank; Bø, Kari

    2011-12-01

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

  20. The stability of aerobic granular sludge under 4-chloroaniline shock in a sequential air-lift bioreactor (SABR).

    Science.gov (United States)

    Zhu, Liang; Lv, Mei-le; Dai, Xin; Zhou, Jia-heng; Xu, Xiang-yang

    2013-07-01

    The aerobic granular sludge technology has a great potential in treatment of municipal wastewater and industrial wastewater containing toxic non-degradable pollutants. However, the formation and structural stability of aerobic granular sludge is susceptible to toxic shock. In the study, the effect of 4-chloroaniline (4-ClA) as a common toxic pollutant on the granular structure and performance was investigated, and the mechanism was revealed to provide more information on 4-ClA degradation with aerobic granular sludge process. The results showed that a 4-ClA shock at influent 200 mg L(-1) could cause the disintegration of aerobic granular sludge and decrease of the pollutant removal performance. The analysis of extracellular polymeric substances (EPS) within the mature and disintegrated granular sludge showed that the decrease of protein content in EPS, especially the components like Amide I 3-turn helix and β-sheet structures and aspartate, was not good for the stability of aerobic granular sludge. The microbial community results demonstrated that the disappearance of dominant bacteria like Kineosphaera limosa or appearance like Acinetobacter, might contribute to the reduction of EPS and disintegration of aerobic granular sludge. PMID:23685649

  1. Low aerobic fitness in Brazilian adolescents

    Directory of Open Access Journals (Sweden)

    Diego Augusto Santos Silva

    2015-04-01

    Full Text Available INTRODUCTION: aerobic fitness is considered one of the most important components of health-related physical fitness, with low levels related to increased risk of premature death from all causes, especially cardiovascular diseases. OBJECTIVE: to identify the characteristics of adolescents at higher risk of low levels of aerobic fitness. METHODS: the study included 696 adolescents 15-17 years of age enrolled in public high schools of Florianópolis, southern Brazil. This cross-sectional epidemiological study was conducted in Florianópolis, Santa Catarina, Brazil. Aerobic fitness was measured using the modified Canadian Aerobic Fitness Test mCAFT. Sociodemographic gender, age, school grade, paternal and maternal schooling, socioeconomic status, and anthropometric variables body weight, height, triceps and subscapular skinfold thickness, sexual maturation, physical activity, sedentary behavior, and eating habits were collected. RESULTS: it was found that 31.5% of adolescents had low aerobic fitness levels, being higher in boys 49.2% compared to girls 20.6%. Moreover, girls with sedentary behavior, overweight and high body fat percentage were the groups most likely to have inadequate aerobic fitness. In males, the groups most likely to have inadequate aerobic fitness were those whose parents studied more than eight years, those with low levels of physical activity, and those with inadequate nutrition and excessive body fat. CONCLUSION: low aerobic fitness levels were present in one third of adolescents and was more prevalent in boys. Lifestyle changes, including replacement of sedentary behaviors by physical and sport activities , may assist in improving the aerobic fitness of Brazilian adolescents.

  2. The Effects of Selected Aerobic Exercise Modalities on Self Esteem among Female Students

    Directory of Open Access Journals (Sweden)

    Norlena Salamuddin

    2014-02-01

    Full Text Available Self-esteem is fundamental component in psychological health and is affected with dynamics of physical exercise. This study explore the effects of selected aerobic exercise programs on self esteem and attempts to determine the most effective aerobic exercise program in boosting self-esteem. This study uses the experimental design on a sample of 120 female undergraduate students. The instruments used were the Self-Esteem Scale. Data was analyzed using inferential statistics. t-test conducted shows significant differences in self-esteem score between pretest and posttest in all modalities of aerobic exercise programs. Analysis of variance reveals that there is a significant difference (F=81.299, p<0.01 between the four modalities of aerobic exercise programs, and post hoc test shows that combination of step-dance aerobics and weight training program is most effective in increasing self esteem among female students. Results of this study contribute to developing the role of aerobic exercise in improving self esteem. It is also useful in assisting to develop policies and programs that enhance self esteem.

  3. Interaction between age and aerobic fitness in determining heart rate dynamics

    International Nuclear Information System (INIS)

    Heart rate variability (HRV) and phase-rectified signal averaging (PRSA) estimates of heart rate dynamics are diminished in older people compared with younger people. However, it is not fully elucidated whether these differences are related to age per se or to the concomitant influence of aerobic fitness. Aerobic fitness (peak oxygen uptake, gas exchange threshold, oxygen uptake kinetics, exercise economy) was assessed in 70 healthy adults (41 male) aged 18–57 years. Participants also underwent a 24 h, ambulatory ECG for the derivation of HRV and PRSA variables. HRV was most sensitive to age and aerobic fitness when measured during the morning period (6 am–12 pm). HRV and PRSA were both diminished with age and were higher in aerobically superior participants. The decline in HRV with age was predominantly attributable to age itself (33%), with aerobic fitness representing an additional modulating factor. The present study also provides tentative evidence that assessment of the influence of aerobic fitness should not rely on .VO2peak alone. These findings demonstrate that age per se is an important factor in determining HRV. However, given the clinical importance of diminished HRV and the immutable nature of aging, the potential significance of physical activity/training to enhance cardiac regulatory function should not be underestimated. (paper)

  4. Ecology, Microbial

    Energy Technology Data Exchange (ETDEWEB)

    Konopka, Allan

    2009-03-19

    Microbial ecology is a relatively young discipline within the field of microbiology. Its modern history spans just the past 60 years, and the field is defined by its emphasis on understanding the interactions of microbes with their environment, rather than their behavior under artificial laboratory conditions. Because microbes are ubiquitous, microbial ecologists study a broad diversity of habitats that range from aquatic to terrestrial to plant- or animal-associated. This has made it a challenge to identify unifying principles within the field. One approach is to recognize that although the activity of microbes in nature have effects at the macroscale, they interact with their physical, chemical and biological milieu at a scale of micrometers. At this scale, several different microbial ecosystems can be defined, based upon association with particles, the presence of environmental gradients and the continuous availability of water. Principles applicable to microbial ecology reflect not only their population ecology and physiological ecology, but also their broad versatility and quantitative importance in the biosphere as biogeochemical catalysts and capacity for rapid physiological and evolutionary responses.

  5. How "healthful" are aerobics classes? Exploring the health and wellness messages in aerobics classes for women.

    Science.gov (United States)

    D'Abundo, Michelle Lee

    2007-01-01

    The purpose of this study was to explore the health messages communicated by aerobics instructors in aerobics classes for women. A theoretical framework influenced by adult learning theory and feminist pedagogy was used in this qualitative study. Over a 3-month period, the practices of five aerobics instructors working at one nonprofit fitness center and one wellness facility were explored. The methods of data collection were one interview with each aerobics instructor and 14 site visits to conduct participant observations and to retrieve of documents. Despite the nonprofit and wellness-based environment of the exercise facilities in this research, there was still an overemphasis on the physical aspect of aerobics classes. Therefore, the potential wellness-related benefits of aerobics classes for women, especially in environments that identified themselves as promoting wellness, were not fully realized. PMID:17148107

  6. Global microbialization of coral reefs.

    Science.gov (United States)

    Haas, Andreas F; Fairoz, Mohamed F M; Kelly, Linda W; Nelson, Craig E; Dinsdale, Elizabeth A; Edwards, Robert A; Giles, Steve; Hatay, Mark; Hisakawa, Nao; Knowles, Ben; Lim, Yan Wei; Maughan, Heather; Pantos, Olga; Roach, Ty N F; Sanchez, Savannah E; Silveira, Cynthia B; Sandin, Stuart; Smith, Jennifer E; Rohwer, Forest

    2016-01-01

    Microbialization refers to the observed shift in ecosystem trophic structure towards higher microbial biomass and energy use. On coral reefs, the proximal causes of microbialization are overfishing and eutrophication, both of which facilitate enhanced growth of fleshy algae, conferring a competitive advantage over calcifying corals and coralline algae. The proposed mechanism for this competitive advantage is the DDAM positive feedback loop (dissolved organic carbon (DOC), disease, algae, microorganism), where DOC released by ungrazed fleshy algae supports copiotrophic, potentially pathogenic bacterial communities, ultimately harming corals and maintaining algal competitive dominance. Using an unprecedented data set of >400 samples from 60 coral reef sites, we show that the central DDAM predictions are consistent across three ocean basins. Reef algal cover is positively correlated with lower concentrations of DOC and higher microbial abundances. On turf and fleshy macroalgal-rich reefs, higher relative abundances of copiotrophic microbial taxa were identified. These microbial communities shift their metabolic potential for carbohydrate degradation from the more energy efficient Embden-Meyerhof-Parnas pathway on coral-dominated reefs to the less efficient Entner-Doudoroff and pentose phosphate pathways on algal-dominated reefs. This 'yield-to-power' switch by microorganism directly threatens reefs via increased hypoxia and greater CO2 release from the microbial respiration of DOC. PMID:27572833

  7. An innovative bioelectrochemical-anaerobic digestion-coupled system for in-situ ammonia recovery and biogas enhancement: process performance and microbial ecology

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

    Ammonia (NH4+/NH3) inhibition during anaerobic digestion process is one of the most frequent problems existing in biogas plants, resulting in unstable process and reduced biogas production. In this study, we developed a novel hybrid system, consisted of a submersed microbial resource recovery cell...

  8. Characterization of biofoulants illustrates different membrane fouling mechanisms for aerobic and anaerobic membrane bioreactors

    KAUST Repository

    Xiong, Yanghui

    2015-11-17

    This study compares the membrane fouling mechanisms of aerobic (AeMBR) and anaerobic membrane bioreactors (AnMBR) of the same reactor configuration at similar operating conditions. Although both the AeMBR and AnMBR achieved more than 90% COD removal efficiency, the fouling mechanisms were different. Molecular weight (MW) fingerprint profiles showed that a majority of fragments in anaerobic soluble microbial products (SMP) were retained by the membrane and some fragments were present in both SMP and in soluble extracellular polymeric substances (EPS), suggesting that the physical retention of SMP components contributed to the AnMBR membrane fouling. One of the dominant fragments was comprised of glycoliproprotein (size 630-640 kD) and correlated in abundance in AnMBR-EPS with the extent of anaerobic membrane fouling. In contrast, all detected AeMBR-SMP fragments permeated through the membrane. Aerobic SMP and soluble EPS also showed very different fingerprinting profiles. A large amount of adenosine triphosphate was present in the AeMBR-EPS, suggesting that microbial activity arising from certain bacterial populations, such as unclassified Comamonadaceae and unclassified Chitinophagaceae, may play a role in aerobic membrane fouling. This study underlines the differences in fouling mechanisms between AeMBR and AnMBR systems and can be applied to facilitate the development of appropriate fouling control strategies.

  9. Molecular characterization of bacterial community in aerobic granular sludge stressed by pentachlorophenol

    Institute of Scientific and Technical Information of China (English)

    LIU He; LI Guangwei; LI Xiufen; CHEN Jian

    2008-01-01

    To characterize the effects of pentachlorophenol (PCP) on the performance and microbial community of aerobic granular sludge insequencing batch reactor (SBR), the web-based terminal restriction fragment length polymorphism (T-RFLP) and real-time PCR (RT-PCR) techniques were used to explore the bacterial community structure. When PCP increased from 0 to 50 mg/L, the COD removalrate changed little, while the ammonia removal rate dropped from 100% to 64.9%. The results of molecular characterization showedthat the quantity of ammonia oxidizing bacteria (AOB) kept constantly, although the number of bacteria species decreased with theincrease of PCP concentation. Significant shift in bacterial community structure at different PCP stresses was observed within aerobicgranular sludge. When the PCP was absent, there are 69 strains in aerobic granular sludge detected by T-RFLP method. With theincrease of PCP, most of bacteria disappeared and only 19 bacteria existed at all five PCP concentrations. These results contributed tocomprehensive understanding of the microbial community structure under the PCP stress and its relationship with the performance forwastewater treatment by aerobic granular sludge.

  10. Neuromodulation of Aerobic Exercise—A Review

    Directory of Open Access Journals (Sweden)

    Saskia eHeijnen

    2016-01-01

    Full Text Available Running, and aerobic exercise in general, is a physical activity that increasingly many people engage in but that also has become popular as a topic for scientific research. Here we review the available studies investigating whether and to which degree aerobic exercise modulates hormones, amino acids, and neurotransmitters levels. In general, it seems that factors such as genes, gender, training status, and hormonal status need to be taken into account to gain a better understanding of the neuromodular underpinnings of aerobic exercise. More research using longitudinal studies and considering individual differences is necessary to determine actual benefits. We suggest that, in order to succeed, aerobic exercise programs should include optimal periodization, prevent overtraining and be tailored to interindividual differences, including neuro-developmental and genetically-based factors.

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

    Science.gov (United States)

    Thomsen, D; Ballor, D L

    1991-03-01

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

  12. Temperature effect on aerobic denitrification and nitrification

    Institute of Scientific and Technical Information of China (English)

    XIE Shu-guang; ZHANG Xiao-jian; WANG Zhan-sheng

    2003-01-01

    Nitrogen loss without organic removal in biofilter was observed and its possible reason was explained. A lower hydraulic loading could improve aerobic denitrification rate. Aerobic denitrification was seriously affected by low temperature(below 10oC). However, nitrification rate remained high when the temperature dropped from 15oC to5oC. It seemed the autotrophic biofilm in BAF could alleviate the adverse effect of low temperature.

  13. Collection of "strengthening sets" of aerobics lesson.\\\\

    OpenAIRE

    CAKL, Vojtěch

    2011-01-01

    The aim of this bachelor study was to create a strengthening sets for aerobic lessons including showing these possisions in practice on selective aerobic lessons . Based on special literature the author had chosen suitable muscle development exercises to increase the body strenth. These exercises were there practised for six weeks continuously. Before and after the research were selected individuals who were compared by 4 exact same tests to detect static and dynamic body strength. The result...

  14. Evaluation of A "Floating" Aerobics Floor

    OpenAIRE

    Favor, Craig M.

    1997-01-01

    Aerobics dance floors often produce annoying floor vibrations in adjacent parts of a building due to the rhythmic impact of the aerobicists. Various types of shock absorbing aerobics and dance floors are widely used to prevent injuries to the participants, but the floors may not prevent vibrations in adjacent areas of the building. The purpose of this investigation is to evaluate a temporary "floating" concrete a...

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

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaodong; Chen, Yan [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Zhang, Xin [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Suzhou Institute of Architectural Design Co., Ltd, Suzhou 215021, Jiangsu Province (China); Jiang, Xinbai; Wu, Shijing [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Shen, Jinyou, E-mail: shenjinyou@mail.njust.edu.cn [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Sun, Xiuyun; Li, Jiansheng; Lu, Lude [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Wang, Lianjun, E-mail: wanglj@mail.njust.edu.cn [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China)

    2015-09-15

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

  16. Stable isotope fractionation during PCE halorespiration and aerobic cisDCE and VC biodegradation

    International Nuclear Information System (INIS)

    The objectives of our study were to identify the anaerobic/aerobic dechlorination mechanisms at two chloroethene-contaminated sites, to assess the isotopic enrichment factors in groundwater microcosms, and to evaluate microbial degradation in the field based on the isotopic signatures. In anaerobic microcosms, a transformation of PCE and TCE to cisDCE was observed. Halo respiration was accompanied by isotopic fractionation effects similar to previous publications. In aerobic microcosms, cisDCE and VC were degraded indicating a co-metabolic degradation of cisDCE in the course of VC degradation. In other experiments, only VC was degraded. Enrichment factors were determined during aerobic degradation of cisDCE and VC. These factors are significantly higher than factors published previously. This study demonstrates that isotope fractionation is suitable for assessing anaerobic/aerobic chloroethene degradation. However, the factors vary for different degradation pathways and micro organisms. Therefore, site-specific enrichment factors have to be determined in order to quantify natural attenuation processes in the field. (author)

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

    International Nuclear Information System (INIS)

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

  18. Development of microorganisms in the chernozem under aerobic and anaerobic conditions

    Science.gov (United States)

    Polyanskaya, L. M.; Gorbacheva, M. A.; Milanovskii, E. Yu.; Zvyagintsev, D. G.

    2010-03-01

    A microbial succession was studied under aerobic and anaerobic conditions by means of experiments with microcosms in different horizons of a chernozem. It was revealed that, under aerobic conditions, all the microorganisms grow irrespective of the soil horizon; fungi and bacteria grow at the first succession stages, and actinomycetes grow at the last stages. It was shown that, in the case of a simulated anaerobiosis commonly used to study anaerobic populations of bacteria, the mycelium of micromycetes grows in the upper part of the chernozem’s A horizon. Under anaerobic conditions, the peak of the mycelium development is shifted from the 3rd to 7th days (typical for aerobic conditions) to the 7th to 15th days of incubation. The level of mycelium length’s stabilization under aerobic and anaerobic conditions also differs: it is higher or lower than the initial one, respectively. Under anaerobic conditions, the growth of fungal mycelium, bacteria, and actinomycetes in the lower part of the A horizon and in the B horizon is extremely weak. There was not any observed growth of actinomycetes in all the chernozem’s horizons under anaerobic conditions.

  19. A neuroimaging investigation of the association between aerobic fitness, hippocampal volume, and memory performance in preadolescent children

    OpenAIRE

    Chaddock, Laura; Erickson, Kirk I.; Prakash, Ruchika Shaurya; Kim, Jennifer S; Voss, Michelle W.; VanPatter, Matt; Pontifex, Matthew B.; Raine, Lauren B.; Konkel, Alex; Hillman, Charles H.; Cohen, Neal J.; Arthur F Kramer

    2010-01-01

    Because children are becoming overweight, unhealthy, and unfit, understanding the neurocognitive benefits of an active lifestyle in childhood has important public health and educational implications. Animal research has indicated that aerobic exercise is related to increased cell proliferation and survival in the hippocampus as well as enhanced hippocampal-dependent learning and memory. Recent evidence extends this relationship to elderly humans by suggesting that high aerobic fitness levels ...

  20. Depletion of Butyrate-Producing Clostridia from the Gut Microbiota Drives an Aerobic Luminal Expansion of Salmonella.

    Science.gov (United States)

    Rivera-Chávez, Fabian; Zhang, Lillian F; Faber, Franziska; Lopez, Christopher A; Byndloss, Mariana X; Olsan, Erin E; Xu, Gege; Velazquez, Eric M; Lebrilla, Carlito B; Winter, Sebastian E; Bäumler, Andreas J

    2016-04-13

    The mammalian intestine is host to a microbial community that prevents pathogen expansion through unknown mechanisms, while antibiotic treatment can increase susceptibility to enteric pathogens. Here we show that streptomycin treatment depleted commensal, butyrate-producing Clostridia from the mouse intestinal lumen, leading to decreased butyrate levels, increased epithelial oxygenation, and aerobic expansion of Salmonella enterica serovar Typhimurium. Epithelial hypoxia and Salmonella restriction could be restored by tributyrin treatment. Clostridia depletion and aerobic Salmonella expansion were also observed in the absence of streptomycin treatment in genetically resistant mice but proceeded with slower kinetics and required the presence of functional Salmonella type III secretion systems. The Salmonella cytochrome bd-II oxidase synergized with nitrate reductases to drive luminal expansion, and both were required for fecal-oral transmission. We conclude that Salmonella virulence factors and antibiotic treatment promote pathogen expansion through the same mechanism: depletion of butyrate-producing Clostridia to elevate epithelial oxygenation, allowing aerobic Salmonella growth. PMID:27078066

  1. Experimental Investigation on the Impact of Aeration Rate and Stirrer Speed on Micro-Aerobic Batch Fermentation

    Directory of Open Access Journals (Sweden)

    L.W.T. Emily

    2009-01-01

    Full Text Available The impact of aeration rate and stirrer speed on micro-aerobic fermentation is studied at laboratory scale. Result suggests that with Baker’s yeast, an increase in aeration rates from very low value can improve bioethanol productivity and yield because it can enhance cell viability. At constant stirrer speed of 150 rpm, the increase in aeration rate from 1 to 1.5 LPM leads to proportional increase in peak Oxygen Uptake Rate (OUR from 600 to 1000 mM L-1 h. This increase coincides with the increase in yield by 7.5%. Interestingly at constant aeration rate of 1.5 LPM, an increase in stirrer speed from 150 to 250 rpm leads to decrease in peak OUR from 1000 to 457 mM L-1 h but increase in yield by 64%. In conclusion, both stirrer speed and aeration rate are important factors which have complex impacts on hydrodynamics and microbial metabolism, which in turn affect productivity and yield. Further study using CFD modeling and simulation method is required to gain better insights into how aeration rate and stirrer speed affect metabolism via the mixing mechanisms in a bioreactor.

  2. Impact of silage additives on aerobic stability and characteristics of high-moisture maize during exposure to air, and on fermented liquid feed

    DEFF Research Database (Denmark)

    Canibe, Nuria; Kristensen, Niels Bastian; Jensen, Bent Borg;

    2014-01-01

    Aims To (i) measure the aerobic stability- and describe the characteristics, during aeration, of high-moisture maize (HMM) treated with various additives, and (ii) describe the microbial characteristics of fermented liquid feed (FLF) added HMM. Methods and Results Four treatments were prepared wi...

  3. Volatile chemical spoilage indexes of raw Atlantic salmon (salmo salar)stored under aerobic condition in relation to microbiological and sensory shelf lives

    Science.gov (United States)

    The purpose of this investigation was to identify and quantify the volatile chemical spoilage indexes (CSIs) for raw Atlantic salmon (Salmo salar) fillets stored under aerobic storage conditions at 4, 10 and 21 degrees C in relation to the determined microbial and sensory shelf lives. The volatile o...

  4. Studies about behavior of microbial degradation of organic compounds

    International Nuclear Information System (INIS)

    Some of TRU waste include organic compounds, thus these organic compounds might be nutrients for microbial growth at disposal site. This disposal system might be exposed to high alkali condition by cement compounds as engineering barrier material. In the former experimental studies, it has been supposed that microbial exist under pH = 12 and the microbial activity acclimated to high alkali condition are able to degrade asphalt under anaerobic condition. Microbes are called extremophile that exist in cruel habitat as high alkali or reductive condition. We know less information about the activity of extremophile, though any recent studies reveal them. In this study, the first investigation is metabolic pathway as microbial activity, the second is microbial degradation of aromatic compounds in anaerobic condition, and the third is microbial activity under high alkali. Microbial metabolic pathway consist of two systems that fulfill their function each other. One system is to generate energy for microbial activities and the other is to convert substances for syntheses of organisms' structure materials. As these systems are based on redox reaction between substances, it is made chart of the microbial activity region using pH, Eh, and depth as parameter, There is much report that microbe is able to degrade aromatic compounds under aerobic or molecular O2 utilizing condition. For degradation of aromatic compounds in anaerobic condition, supplying electron acceptor is required. Co-metabolism and microbial consortia has important role, too. Alcalophile has individual transporting system depending Na+ and acidic compounds contained in cell wall. Generating energy is key for survival and growth under high alkali condition. Co-metabolism and microbial consortia are effective for microbial degradation of aromatic compounds under high alkali and reductive condition, and utilizable electron acceptor and degradable organic compounds are required for keeping microbial activity and

  5. Biodegradation of triclosan and formation of methyl-triclosan in activated sludge under aerobic conditions

    DEFF Research Database (Denmark)

    Chen, Xijuan; Nielsen, Jeppe Lund; Furgal, Karolina;

    2011-01-01

    triclosan- methyl was investigated in activated sludge from a standard activated sludge WWTP equipped with enhanced biological phosphorus removal. The removal was found to occur mainly under aerobic conditions while under anoxic (nitrate reducing) and anaerobic conditions rather low removal rates were...

  6. Inhibitory Effect of Maillard Reaction Products on Growth of the Aerobic Marine Hyperthermophilic Archaeon Aeropyrum pernix

    OpenAIRE

    Kim, Kee Woung; Lee, Sun Bok

    2003-01-01

    It was found that the growth of Aeropyrum pernix was severely inhibited in a medium containing reducing sugars and tryptone due to the formation of Maillard reaction products. The rate of the Maillard browning reaction was markedly enhanced under aerobic conditions, and the addition of Maillard reaction products to the culture medium caused fatal growth inhibition.

  7. The microbial methane cycle in subsurface sediments. Final project report, July 1, 1993--August 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Grossman, E.L.; Ammerman, J.W. [Texas A and M Univ., College Station, TX (United States); Suflita, J.M. [Univ. of Oklahoma, Norman, OK (United States). Dept. of Botany and Microbiology

    1997-12-31

    The objectives of this study were to determine the factors controlling microbial activity and survival in the subsurface and, specifically, to determine whether microbial communities in aquitards and in aquifer microenvironments provide electron donors and/or acceptors that enhance microbial survival in aquifers. Although the original objectives were to focus on methane cycling, the authors pursued an opportunity to study sulfur cycling in aquifer systems, a process of much greater importance in microbial activity and survival, and in the mobility of metals in the subsurface. Furthermore, sulfur cycling is pertinent to the Subsurface Science Program`s study at Cerro Negro, New Mexico. The study combined field and laboratory approaches and microbiological, molecular, geochemical, and hydrogeological techniques. During drilling operations, sediments were collected aseptically and assayed for a variety of microorganisms and metabolic capabilities including total counts, viable aerobic heterotrophs, total anaerobic heterotrophs, sulfate reducing bacteria (SRB) and sulfate reduction activity (in situ and in slurries), methanogens, methanotrophs, and Fe- and S-oxidizers, among others. Geochemical analyses of sediments included organic carbon content and {sup 13}C/{sup 12}C ratio, sulfur chemistry (reduced sulfur, sulfate), {sup 34}S/{sup 32}S, {sup 13}C/{sup 12}C, {sup 14}C, tritium, etc. The authors drilled eight boreholes in the Eocene Yegua formation at four localities on the Texas A&M University campus using a hollow-stem auger drilling rig. The drilling pattern forms a T, with three well clusters along the dip direction and two along strike. Four boreholes were sampled for sediments and screened at the deepest sand interval encountered, and four boreholes were drilled to install wells in shallower sands. Boreholes range in depth from 8 to 31 m, with screened intervals ranging from 6 to 31 m. Below are the results of these field studies.

  8. Effects of activated sludge flocs and pellets seeds on aerobic granule properties

    Institute of Scientific and Technical Information of China (English)

    Huacheng Xu; Pinjing He; Guanzhao Wang; Liming Shao

    2011-01-01

    Aerobic granules seeded with activated sludge fiocs and pellets (obtained from activated sludge flocs) were cultivated in two sequencing batch reactors and their characteristics were compared.Compared with granules seeded with activated sludge flocs, those seeded with pellets had shorter start-up time, larger diameter, better chemical oxygen demand removal efficiency, and higher hydrophobicity, suspended solid concentration, and Mg2+ content.The different inocula led the granule surface with different microbial morphologies, but did not result in different distribution patterns of extracellular polymeric substances and cells.The anaerobic bacterium Anoxybacillus sp.was detected in the granules seeded with pellets.These results highlighted the advantage of pellet over activated sludge floc as the seed for aerobic granulation and wastewater treatment.

  9. Impact of influent COD/N ratio on disintegration of aerobic granular sludge.

    Science.gov (United States)

    Luo, Jinghai; Hao, Tianwei; Wei, Li; Mackey, Hamish R; Lin, Ziqiao; Chen, Guang-Hao

    2014-10-01

    Disintegration of aerobic granular sludge (AGS) is a challenging issue in the long-term operation of an AGS system. Chemical oxygen demand (COD)-to-nitrogen (N) ratio (COD/N), often variable in industrial wastewaters, could be a destabilizing factor causing granule disintegration. This study investigates the impact of this ratio on AGS disintegration and identifies the key causes, through close monitoring of AGS changes in its physical and chemical characteristics, microbial community and treatment performance. For specific comparison, two lab-scale air-lift type sequencing batch reactors, one for aerobic granular and the other for flocculent sludge, were operated in parallel with three COD/N ratios (4, 2, 1) applied in the influent of each reactor. The decreased COD/N ratios of 2 and 1 strongly influenced the stability of AGS with regard to physical properties and nitrification efficiency, leading to AGS disintegration when the ratio was decreased to 1. Comparatively the flocculent sludge maintained relatively stable structure and nitrification efficiency under all tested COD/N ratios. The lowest COD/N ratio resulted in a large microbial community shift and extracellular polymeric substances (EPS) reduction in both flocculent and granular sludges. The disintegration of AGS was associated with two possible causes: 1) reduction in net tyrosine production in the EPS and 2) a major microbial community shift including reduction in filamentous bacteria leading to the collapse of granule structure. PMID:24950459

  10. Formation of Aerobic Granular Sludge in Sequencing Batch Reactor: Comparison of Different Divalent Metal Ions as Cofactors

    Science.gov (United States)

    Liu, Lin; Gao, Dawen; Zhang, Min

    2010-11-01

    The two sequencing batch reactors (SBRs) were operated to investigate the different effect of Ca2+ and Mg2+ augmentation on aerobic granulation. R1 was augmented with Ca2+ at 40 mg/L, while Mg+ was added to R2 with 40 mg/L. Results indicated that R1 had a faster granulation process, and aerobic granulation reached the steady state after 60 cycles in R1 but 80 cycles in R2. The mean diameter of the mature granules in R1 was 1.6 mm which was consistently larger than that (0.8 mm) in R2, and aerobic granules in R1 also showed a higher physical strength. However, the mature granules in R2 had the higher production yield of polysaccharides and proteins, and aerobic granules in R2 experienced a faster substrate biodegradation. Microbial and genetic characteristics in mature granules were analyzed using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) techniques. The results revealed that Mg2+ addition led to higher microbial diversity in mature granules. In addition, the uncultured bacterium (AB447697) was major specie in R1, and β-proteobacterium was dominant in R2.

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

    Directory of Open Access Journals (Sweden)

    Rehab Z. Abdallah

    2014-09-01

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

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

    OpenAIRE

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

    1983-01-01

    An isotopic tracer assay based on the hydrogenase-dependent formation of tritiated water from tritium gas was developed for in life analysis of microbial hydrogen transformation. This method allowed detection of bacterial hydrogen metabolism in pure cultures or in natural samples obtained from aquatic ecosystems. A differentiation between chemical-biological and aerobic-anaerobic hydrogen metabolism was established by variation of the experimental incubation temperature or by addition of sele...

  13. Removal of fluoxetine and its effects in the performance of an aerobic granular sludge sequential batch reactor

    OpenAIRE

    Moreira, Irina S.; Amorim, Catarina L.; Ribeiro, Ana R.; Mesquita, Raquel B. R.; Rangel, António O. S. S.; Van Loosdrecht, Mark C.M.; Tiritan, Maria E.; Castro, Paula M. L.

    2015-01-01

    Fluoxetine (FLX) is a chiral fluorinated pharmaceutical mainly indicated for treatment of depression and is one of the most distributed drugs. There is a clear evidence of environmental contamination with this drug. Aerobic granular sludge sequencing batch reactors constitute a promising technology for wastewater treatment; however the removal of carbon and nutrients can be affected by micropollutants. In this study, the fate and effect of FLX on reactor performance and on microbi...

  14. Influence of aerobic exercise training on post-exercise responses of aortic pulse pressure and augmentation pressure in postmenopausal women

    Directory of Open Access Journals (Sweden)

    Nobuhiko eAkazawa

    2015-10-01

    Full Text Available Central arterial blood pressure (BP is more predictive of future cardiovascular events than is brachial BP because it reflects the BP load imposed on the left ventricle with greater accuracy. However, little is known about the effects of exercise training on central hemodynamic response to acute exercise. The purpose of the present study was to determine the influence of an aerobic exercise regimen on the response of aortic BP after a single aerobic exercise in postmenopausal women. Nine healthy postmenopausal women (age: 61 ± 2 years participated in a 12-week aerobic exercise training regimen. Before and after the training, each subjects performed a single bout of cycling at ventilatory thresholds for 30 min. We evaluated the post-exercise aortic BP response, which was estimated via the general transfer function from applanation tonometry. After the initial pre-training aerobic exercise session, aortic BP did not change significantly: however, aortic pulse pressure and augmentation pressure were significantly attenuated after the single aerobic exercise session following the 12-week training regimen. The present study demonstrated that a regular aerobic exercise training regimen induced the post-exercise reduction of aortic pulse pressure and augmentation pressure. Regular aerobic exercise training may enhance post-exercise reduction in aortic BP.

  15. Mechanism of aerobic biological destabilisation of wool scour effluent emulsions.

    Science.gov (United States)

    Poole, Andrew J; Cord-Ruwisch, Ralf; William Jones, F

    2005-07-01

    Wool scouring effluent is a highly polluted industrial wastewater in which the main pollutant, wool wax, is held in a stable oil-in-water emulsion by non-ionic detergent. The use of microbial action to cause emulsion destabilisation has been proposed as a new treatment strategy for this effluent stream. This strategy aims at improving aerobic treatment performance by physically removing the high-COD, slowly bio-degradable wool wax from the system without bio-degradation. The mechanism by which an aerobic-mixed culture destabilises the wool scouring effluent emulsion was investigated. Our results show that destabilisation is due to partial bio-degradation of both the scouring detergent and the wool wax. Cleavage of the wool wax esters was the first stage in wax degradation, when 40-50% of wax was de-emulsified. Over the same period, detergent degradation was low, at 7-21%. With further incubation, detergent degradation increased, aiding further breakdown of the emulsion. The degradation of the detergent, a nonylphenol ethoxylate, resulted in both a reduction in molar concentration (of up to 82%) and a shortening of the ethoxylate chain length. The latter reduced the hydrophile-lipophile balance (HLB) from 12 to approximately 7, thereby reducing the ability of the residual detergent to stabilise the emulsion. Analysis of the emulsified and de-emulsified wax fractions could not identify a group of compounds that were preferentially de-emulsified based on molecular weight or polarity. These findings will assist in using a de-emulsification strategy in both existing and new treatment systems in order to save on aeration costs and treatment times for biological treatment of this highly polluted wastewater. PMID:15979119

  16. Microbial Metalloproteomics

    Directory of Open Access Journals (Sweden)

    Peter-Leon Hagedoorn

    2015-12-01

    Full Text Available Metalloproteomics is a rapidly developing field of science that involves the comprehensive analysis of all metal-containing or metal-binding proteins in a biological sample. The purpose of this review is to offer a comprehensive overview of the research involving approaches that can be categorized as inductively coupled plasma (ICP-MS based methods, X-ray absorption/fluorescence, radionuclide based methods and bioinformatics. Important discoveries in microbial proteomics will be reviewed, as well as the outlook to new emerging approaches and research areas.

  17. Microbial effects

    International Nuclear Information System (INIS)

    The long term safety and integrity of radioactive waste disposal sites proposed for use by Ontario Hydro may be affected by the release of radioactive gases. Microbes mediate the primary pathways of waste degradation and hence an assessment of their potential to produce gaseous end products from the breakdown of low level waste was performed. Due to a number of unknown variables, assumptions were made regarding environmental and waste conditions that controlled microbial activity; however, it was concluded that 14C and 3H would be produced, albeit over a long time scale of about 1500 years for 14C in the worst case situation

  18. Microbial biotechnology.

    Science.gov (United States)

    Demain, A L

    2000-01-01

    For thousands of years, microorganisms have been used to supply products such as bread, beer and wine. A second phase of traditional microbial biotechnology began during World War I and resulted in the development of the acetone-butanol and glycerol fermentations, followed by processes yielding, for example, citric acid, vitamins and antibiotics. In the early 1970s, traditional industrial microbiology was merged with molecular biology to yield more than 40 biopharmaceutical products, such as erythropoietin, human growth hormone and interferons. Today, microbiology is a major participant in global industry, especially in the pharmaceutical, food and chemical industries. PMID:10631778

  19. Microbial Ecosystems, Protection of

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Nelson, K.E.

    2014-01-01

    Synonyms Conservation of microbial diversity and ecosystem functions provided by microbes; Preservation of microbial diversity and ecosystem functions provided by microbes Definition The use, management, and conservation of ecosystems in order to preserve microbial diversity and functioning. Introdu

  20. Extensive functional evaluations to monitor aerobic training in Becker Muscular Dystrophy: A case report

    Directory of Open Access Journals (Sweden)

    Caterina Tramonti

    2016-06-01

    Full Text Available Low-intensity aerobic training seems to have positive effects on muscle strength, endurance and fatigue in Becker Muscular Dystrophy (BMD patients. We describe the case of a 33-year old BMD man, who performed a four-week aerobic training. Extensive functional evaluations were executed to monitor the efficacy of the rehabilitative treatment. Results evidenced an increased force exertion and an improvement in muscle contraction during sustained exercise. An improvement of walk velocity, together with agility, endurance capacity and oxygen consumption during exercise was observed. Moreover, an enhanced metabolic efficiency was evidenced, as shown by reduced lactate blood levels after training. Interestingly, CK showed higher levels after the training protocol, revealing possible muscle damage. In conclusion, aerobic training may represent an effective method improving exercise performance, functional status and metabolic efficiency. Anyway, a careful functional assessment should be taken into account as a useful approach in the management of the disease’s rehabilitative treatment.

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

    Science.gov (United States)

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

    2012-07-01

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

  2. Beneifcial mechanisms of aerobic exercise on hepatic lipid metabolism in non-alcoholic fatty liver disease

    Institute of Scientific and Technical Information of China (English)

    Rui Guo; Emily C Liong; Kwok Fai So; Man-Lung Fung; George L Tipoe

    2015-01-01

    BACKGROUND:Non-alcoholic fatty liver disease (NAFLD) refers to any fatty liver disease that is not due to excessive use of alcohol. NAFLD probably results from abnormal hepatic lipid metabolism and insulin resistance. Aerobic exercise is shown to improve NAFLD. This review aimed to evaluate the molecular mechanisms involved in the beneifcial effects of aerobic exercise on NAFLD. DATA SOURCE:We searched articles in English on the role of aerobic exercise in NAFLD therapy in PubMed. RESULTS:The mechanisms of chronic aerobic exercise in regulating the outcome of NAFLD include: (i) reducing in-trahepatic fat content by down-regulating sterol regulatory element-binding protein-1c and up-regulating peroxisome proliferator-activated receptorγ expression levels; (ii) decreas-ing hepatic oxidative stress through modulating the reactive oxygen species, and enhancing antioxidant enzymes such as catalase and glutathione peroxidase; (iii) ameliorating hepatic inlfammation via the inhibition of pro-inlfammatory media-tors such as tumor necrosis factor-alpha and interleukin-1 beta; (iv) attenuating mitochondrial dependent apoptosis by reducing cytochrome C released from the mitochondria to the cytosol; and (v) inducing hepato-protective autophagy. CONCLUSION:Aerobic exercise, via different mechanisms, signiifcantly decreases the fat content of the liver and improves the outcomes of patients with NAFLD.

  3. Biodegradation of p-cresol by aerobic granules in sequencing batch reactor

    Institute of Scientific and Technical Information of China (English)

    Farrukh Basheer; I.H.Farooqi

    2012-01-01

    The cultivation of aerobic granules in sequencing batch reactor for the biodegradation of p-cresol was studied.The reactor was started with 100 mg/L of p-cresol.Aerobic granules first appeared within one month of start up.The granules were large and strong and had a compact structure.The diameter of stable granules was in the range of 1-5 mm.The integrity coefficient and granules density was found to be 96% and 1046 kg/m3,respectively.The settling velocity of granules was found to be in the range of 2×10-2-6×10-2 m/sec.The aerobic granules were able to degrade p-cresol upto 800 mg/L at a removal efficiency of 88%.Specific p-cresol degradation rate in aerobic granules followed Haldane model for substrate inhibition.High specific p-cresol degradation rate up to 0.96 g pcresol/(g VSS.day) were sustained upto p-cresol concentration of 400 mg/L.Higher removal efficiency,good settling characteristics of aerobic granules,makes sequencing batch reactor suitable for enhancing the microorganism potential for biodegradation of inhibitory compounds.

  4. Influence of Aerobic Training and Combinations of Interventions on Cognition and Neuroplasticity after Stroke.

    Science.gov (United States)

    Constans, Annabelle; Pin-Barre, Caroline; Temprado, Jean-Jacques; Decherchi, Patrick; Laurin, Jérôme

    2016-01-01

    Stroke often aggravated age-related cognitive impairments that strongly affect several aspects of quality of life. However, few studies are, to date, focused on rehabilitation strategies that could improve cognition. Among possible interventions, aerobic training is well known to enhance cardiovascular and motor functions but may also induce beneficial effects on cognitive functions. To assess the effectiveness of aerobic training on cognition, it seems necessary to know whether training promotes the neuroplasticity in brain areas involved in cognitive functions. In the present review, we first explore in both human and animal how aerobic training could improve cognition after stroke by highlighting the neuroplasticity mechanisms. Then, we address the potential effect of combinations between aerobic training with other interventions, including resistance exercises and pharmacological treatments. In addition, we postulate that classic recommendations for aerobic training need to be reconsidered to target both cognition and motor recovery because the current guidelines are only focused on cardiovascular and motor recovery. Finally, methodological limitations of training programs and cognitive function assessment are also developed in this review to clarify their effectiveness in stroke patients. PMID:27445801

  5. Effects of extracellular polymer substances on aerobic granulation in sequencing batch reactors

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-ping; LIU Li-li; YAO Jie; SUN Li-xin; CAI Wei-min

    2009-01-01

    The effects of extracellular polymeric substances (EPS) on aerobic granulation in sequencing batch reactors (SBR) were investigated by evaluating the EPS content, and the relationship between EPS composition and surface properties of glucose-fed aerobic granules. The results show that aerobic granular sludge contains more EPS than seed sludge, and it is about 47 mg/gMLSS. Corresponding to the changes of EPS, the surface charge of microorganisms in granules increases from -0. 732 to -0. 845 meq/gMLSS, whereas the hydrophobicry changes significantly from 48.46% to 73. 16%. It is obviously that changes of EPS in sludge alter the negative surface charge and hydrophobieity of microorganisms in granules, enhance the polymeric interaction and promote the aerobic granulation. Moreover, EPS can serve as carbon and energy reserves in granulation, thus the growth between the interior and exterior bacteria is balanced, and the integrality of granules is maintained.SEM observation of the granules exhibits that EPS in granules are ropy ; by mixing with bacteria, compact matrix structure can be formed. The distribution of EPS in granules profiles the importance of EPS storage. It can be concluded that EPS play a crucial role in aerobic granulation.

  6. Degradation of the herbicide mecoprop in an aerobic aquifer determined by laboratory batch studies

    DEFF Research Database (Denmark)

    Heron, Gorm; Christensen, Thomas Højlund

    1992-01-01

    The potential of a shallow aerobic aquifer to degrade the herbicide Mecoprop (2-(2-methyl-4-chlorophenoxy)propionic acid) was evaluated in the laboratory using groundwater and sediment suspension batches. Mecoprop was added to the batches to obtain concentrations of 65, 140, 400 and 1400 μg...... the second lag period. The natural degradation potential for mecoprop varied among locations within a distance of few metres and was affected by different mecoprop concentrations. The observed stepwise degradation was supposedly due to different populations or different microbial mechanisms involved...

  7. Microbial Transformations of Actinides and Other Radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Francis,A.J.; Dodge, C. J.

    2009-01-07

    Microorganisms can affect the stability and mobility of the actinides and other radionuclides released from nuclear fuel cycle and from nuclear fuel reprocessing plants. Under appropriate conditions, microorganisms can alter the chemical speciation, solubility and sorption properties and thus could increase or decrease the concentrations of radionuclides in solution in the environment and the bioavailability. Dissolution or immobilization of radionuclides is brought about by direct enzymatic action or indirect non-enzymatic action of microorganisms. Although the physical, chemical, and geochemical processes affecting dissolution, precipitation, and mobilization of radionuclides have been extensively investigated, we have only limited information on the effects of microbial processes and biochemical mechanisms which affect the stability and mobility of radionuclides. The mechanisms of microbial transformations of the major and minor actinides U, Pu, Cm, Am, Np, the fission products and other radionuclides such as Ra, Tc, I, Cs, Sr, under aerobic and anaerobic conditions in the presence of electron donors and acceptors are reviewed.

  8. MICROBIAL TRANSFORMATIONS OF URANIUM COMPLEXED WITH ORGANIC AND INORGANIC LIGANDS.

    Energy Technology Data Exchange (ETDEWEB)

    FRANCIS,A.J.

    2002-09-15

    Biotransformation of various chemical forms of uranium present in wastes, contaminated soils and materials by microorganisms under different process conditions such as aerobic and anaerobic (denitrifying, iron-reducing, fermentative, and sulfate-reducing) conditions will affect the solubility, bioavailability, and mobility of uranium in the natural environment. Fundamental understanding of the mechanisms of microbial transformations of uranium under a variety of environmental conditions will be useful in developing appropriate remediation and waste management strategies as well as predicting the microbial impacts on the long-term stewardship of contaminated sites.

  9. Stimulatory effects of a microbially dechlorinated polychlorinated biphenyl (PCB) mixture on rat uterine contraction in vitro

    OpenAIRE

    Tsuneta, Taeko; Loch-Caruso, Rita; Quensen, John F.; Boyd, Stephen A.; Hanna, Mona; Grindatti, Carmen

    2008-01-01

    Microbially mediated reductive dechlorination has been advocated as the first part of a two-stage (anaerobic/aerobic) biotreatment process for polychlorinated biphenyls (PCBs) in sediments, and is generally viewed as a detoxication process. However, previous studies suggest that microbial dechlorination increases ability to stimulate uterine contractions compared with the original PCB mixtures. Here, we investigate the composition and uterotonic activity of the commercial PCB mixture Aroclor ...

  10. Effect of Pretreating Waste Activated Sludge with Ozone on the Performance of Aerobic Digestion Process

    Directory of Open Access Journals (Sweden)

    H Asilian

    2009-03-01

    Full Text Available "n "nBackground and Objectives: A conventional treatment to stabilize the excess activated sludge is the aerobic digestion process but due to long aeration time, it requires large equipments as well as high investment cost. Because of high oxidation potential of ozone, sludge ozonation enhances stabilization rate and reduces sludge treatment equipment size and cost. Therefore, in this study, the combination of pretreatment with ozone and aerobic digestion processes were investigated."nMaterials and Methods: The experimental set-up consisted of an ozone generator and ozonation reactor with the total volume of 2 L. Removal percentages of TSS, VS, total and soluble COD, HPC, fecal coliform and settable solids were measured in integrated process compared to the single ones."nResults: The results of this research indicated that the aerobic digestion of waste activated sludge during 10 days could reduce 38% of volatile solids and thus obtaining the EPA standard. Also, the results of combined ozonation and aerobic digestion revealed that the pre-ozonation at 0.25 g O3/g TS or 0.5 g O3/g TS with 6 or 3 days aeration, respectively, could achieve 38% reduction in VS and hence the requirement set by EPA. Therefore, integration of pre-ozonation with aerobic digestion can significantly reduce the digestion time to attain the standards."nConclusion: The sludge pre-ozonation with low dose of ozone due to solids disintegration can enhance the efficiency of aerobic digestion in waste activated sludge stabilization, and consequently decrease size of equipments, air requirement, investment and probably operation cost.

  11. Microbial Life of North Pacific Oceanic Crust

    Science.gov (United States)

    Schumann, G.; Koos, R.; Manz, W.; Reitner, J.

    2003-12-01

    Information on the microbiology of the deep subsurface is necessary in order to understand the factors controlling the rate and extent of the microbially catalyzed reactions that influence the geophysical properties of these environments. Drilling into 45-Ma oceanic basaltic crust in a deepwater environment during ODP Leg 200 provided a promising opportunity to explore the abundance, diversity and activity of micro-organisms. The combined use of culture-independent molecular phylogenetic analyses and enrichment culture techniques is an advantageous approach in investigating subsurface microbial ecosystems. Enrichment culture methods allow the evaluation of potential activities and functions. Microbiological investigations revealed few aerobic cultivable, in part hitherto unknown, micro-organisms in deep submarine sediments and basaltic lava flows. 16S rDNA sequencing of isolates from sediment revealed the next relatives to be members of the genera Halomonas, Pseudomonas, and Lactobacillus. Within the Pseudomonadaceae the closest relative is Acinetobacter sp., which was isolated from a deep subsurface environment. The next phylogenetical relatives within the Halomonadaceae are bacteria typically isolated from Soda lakes, which are considered as model of early life conditions. Interestingly, not only sediment bacteria could be obtained in pure culture. Aerobic strains could also be successfully isolated from the massive tholeiitic basalt layer at a depth of 76.16 mbsf (46 m below the sediment/basement contact). These particular isolates are gram-positive with low G+C content of DNA, phylogenetically affiliated to the phylum Firmicutes. The closest neighbors are e.g. a marine Bacillus isolated from the Gulf of Mexico and a low G+C gram-positive bacterium, which belongs to the microbial flora in the deepest sea mud of the Mariana Trench, isolated from a depth of 10,897 m. Based on the similarity values, the isolates represent hitherto undescribed species of the deep

  12. Enhancing Signal Output and Avoiding BOD/Toxicity Combined Shock Interference by Operating a Microbial Fuel Cell Sensor with an Optimized Background Concentration of Organic Matter.

    Science.gov (United States)

    Jiang, Yong; Liang, Peng; Liu, Panpan; Bian, Yanhong; Miao, Bo; Sun, Xueliang; Zhang, Helan; Huang, Xia

    2016-01-01

    In the monitoring of pollutants in an aquatic environment, it is important to preserve water quality safety. Among the available analysis methods, the microbial fuel cell (MFC) sensor has recently been used as a sustainable and on-line electrochemical microbial biosensor for biochemical oxygen demand (BOD) and toxicity, respectively. However, the effect of the background organic matter concentration on toxicity monitoring when using an MFC sensor is not clear and there is no effective strategy available to avoid the signal interference by the combined shock of BOD and toxicity. Thus, the signal interference by the combined shock of BOD and toxicity was systematically studied in this experiment. The background organic matter concentration was optimized in this study and it should be fixed at a high level of oversaturation for maximizing the signal output when the current change (ΔI) is selected to correlate with the concentration of a toxic agent. When the inhibition ratio (IR) is selected, on the other hand, it should be fixed as low as possible near the detection limit for maximizing the signal output. At least two MFC sensors operated with high and low organic matter concentrations and a response chart generated from pre-experiment data were both required to make qualitative distinctions of the four types of combined shock caused by a sudden change in BOD and toxicity. PMID:27563887

  13. Enhancing Signal Output and Avoiding BOD/Toxicity Combined Shock Interference by Operating a Microbial Fuel Cell Sensor with an Optimized Background Concentration of Organic Matter

    Directory of Open Access Journals (Sweden)

    Yong Jiang

    2016-08-01

    Full Text Available In the monitoring of pollutants in an aquatic environment, it is important to preserve water quality safety. Among the available analysis methods, the microbial fuel cell (MFC sensor has recently been used as a sustainable and on-line electrochemical microbial biosensor for biochemical oxygen demand (BOD and toxicity, respectively. However, the effect of the background organic matter concentration on toxicity monitoring when using an MFC sensor is not clear and there is no effective strategy available to avoid the signal interference by the combined shock of BOD and toxicity. Thus, the signal interference by the combined shock of BOD and toxicity was systematically studied in this experiment. The background organic matter concentration was optimized in this study and it should be fixed at a high level of oversaturation for maximizing the signal output when the current change (ΔI is selected to correlate with the concentration of a toxic agent. When the inhibition ratio (IR is selected, on the other hand, it should be fixed as low as possible near the detection limit for maximizing the signal output. At least two MFC sensors operated with high and low organic matter concentrations and a response chart generated from pre-experiment data were both required to make qualitative distinctions of the four types of combined shock caused by a sudden change in BOD and toxicity.

  14. Microbial field pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Coates, J.D.; Chisholm, J.L.

    1993-05-01

    A multi-well microbially enhanced oil recovery field pilot has been performed in the Southeast Vassar Vertz Sand Unit in Payne County, Oklahoma. The primary emphasis of the experiment was preferential plugging of high permeability zones for the purpose of improving waterflood sweep efficiency. Studies were performed to determine reservoir chemistry, ecology, and indigenous bacteria populations. Growth experiments were used to select a nutrient system compatible with the reservoir that encouraged growth of a group of indigenous nitrate-using bacteria and inhibit growth of sulfate-reducing bacteria. A specific field pilot area behind an active line drive waterflood was selected. Surface facilities were designed and installed. Injection protocols of bulk nutrient materials were prepared to facilitate uniform distribution of nutrients within the pilot area. By the end of December, 1991, 82.5 tons (75.0 tonnes) of nutrients had been injected in the field. A tracer test identified significant heterogeneity in the SEVVSU and made it necessary to monitor additional production wells in the field. The tracer tests and changes in production behavior indicate the additional production wells monitored during the field trial were also affected. Eighty two and one half barrels (13.1 m[sup 3]) of tertiary oil have been recovered. Microbial activity has increased CO[sub 2] content as indicated by increased alkalinity. A temporary rise in sulfide concentration was experienced. These indicate an active microbial community was generated in the field by the nutrient injection. Pilot area interwell pressure interference test results showed that significant permeability reduction occurred. The interwell permeabilities in the pilot area between the injector and the three pilot production wells were made more uniform which indicates a successful preferential plugging enhanced oil recovery project.

  15. ANAEROBIC AND AEROBIC TREATMENT OF CHLORINATED ALIPHATIC COMPOUNDS

    Science.gov (United States)

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

  16. Flat laminated microbial mat communities

    Science.gov (United States)

    Franks, Jonathan; Stolz, John F.

    2009-10-01

    Flat laminated microbial mats are complex microbial ecosystems that inhabit a wide range of environments (e.g., caves, iron springs, thermal springs and pools, salt marshes, hypersaline ponds and lagoons, methane and petroleum seeps, sea mounts, deep sea vents, arctic dry valleys). Their community structure is defined by physical (e.g., light quantity and quality, temperature, density and pressure) and chemical (e.g., oxygen, oxidation/reduction potential, salinity, pH, available electron acceptors and donors, chemical species) parameters as well as species interactions. The main primary producers may be photoautotrophs (e.g., cyanobacteria, purple phototrophs, green phototrophs) or chemolithoautophs (e.g., colorless sulfur oxidizing bacteria). Anaerobic phototrophy may predominate in organic rich environments that support high rates of respiration. These communities are dynamic systems exhibiting both spatial and temporal heterogeneity. They are characterized by steep gradients with microenvironments on the submillimeter scale. Diel oscillations in the physical-chemical profile (e.g., oxygen, hydrogen sulfide, pH) and species distribution are typical for phototroph-dominated communities. Flat laminated microbial mats are often sites of robust biogeochemical cycling. In addition to well-established modes of metabolism for phototrophy (oxygenic and non-oxygenic), respiration (both aerobic and anaerobic), and fermentation, novel energetic pathways have been discovered (e.g., nitrate reduction couple to the oxidation of ammonia, sulfur, or arsenite). The application of culture-independent techniques (e.g., 16S rRNA clonal libraries, metagenomics), continue to expand our understanding of species composition and metabolic functions of these complex ecosystems.

  17. THE RATE AND NATURE OF WOMEN INJURIES IN STEP AEROBICS

    OpenAIRE

    Gholam Ali Ghasemi; Vahid Zolaktaf; Fereshteh Kazemi

    2011-01-01

    Step aerobics is a form of aerobic exercise that utilizes a 90×45×20 centimeter platform. ItsInternational competitions are held annually. This sport is popular in Iranian specialist femalesport clubs and its national competitions are growing gradually. The purpose of this survey wasto determine the rate and nature of sport injury in Iranian athletes of step aerobics. Weadministered a structured interview using a modified version of standard questionnaire of"Aerobics Pathology". The populatio...

  18. Biotechnology for aerobic conversion of food waste into organic fertilizer.

    Science.gov (United States)

    Stabnikova, Olena; Ding, Hong-Bo; Tay, Joo-Hwa; Wang, Jing-Yuan

    2005-02-01

    A biotechnology for aerobic conversion of food waste into organic fertilizer under controlled aeration, stirring, pH and temperature at 55-65 degrees C, is proposed. To maintain neutral pH at the beginning of the bioconversion 5% CaCO3 was added to the total solids of the food waste. The addition of 20% horticultural waste compost as a bulking agent to the food wastes (w.w./w.w.), improved the bioconversion and increased the stability of the final product. No starter culture was needed for aerobic bioconversion of food waste into organic fertilizer for 10 days. The low contents of heavy metals in the raw materials used in the bioconversions ensured the safety of fertilizer from food waste for application in agriculture. The addition of 4% organic fertilizer to the subsoil increased the yield and growth of Ipomoea aquatica (Kang Kong) by 1.5 to 2 times. The addition of phosphorus is required to enhance the positive effect of organic fertilizer on plant growth. PMID:15751394

  19. 微生物采油技术的研究与应用%THE RESEARCH AND APPLICATION OF MICROBIAL ENHANCED OIL RECOVERY

    Institute of Scientific and Technical Information of China (English)

    雷光伦

    2001-01-01

    简要阐述了微生物采油技术、微生物采油技术的发展及微生物采油优势。介绍了用于微生物采油的自然菌和工程菌以及我国微生物采油菌的分离、筛选、产物分析、提高采收率机理研究的方法、采用手段和所取得的研究成果,在对微生物采油机理研究基础上提出了微生物采油数学模型。分析我国微生物采油矿场试验的成败后,指出微生物采油更适合于我国下列油藏:小于40℃的低温油藏;普通稠油油藏;含蜡油藏;含水小于80%的断块小油藏。%The information and results of MEOR study and applica tion have been compiled in this paper.In China,great progress have been achieved on research of strains and mechanism in laboratory,many kinds of formation have been candidates as field pilots to conduct microbial treatment or microbial en hanced waterflooding.The results show microorganism can increase oil production and decrease water cut.The technology of MEOR will become an important method i n improving oil recovery in China.

  20. Enhanced bioreduction of iron and arsenic in sediment by biochar amendment influencing microbial community composition and dissolved organic matter content and composition.

    Science.gov (United States)

    Chen, Zheng; Wang, Yuanpeng; Xia, Dong; Jiang, Xiuli; Fu, Dun; Shen, Liang; Wang, Haitao; Li, Qing Biao

    2016-07-01

    Biochar derived from the pyrolysis at 500 °C with fresh biogas slurry and residue, was conducted to investigate its potential role in mediating the speciation and mobilization of As(V) and Fe(III) from arsenic-contaminated tailing mine sediment, with consideration of the changes in microbial populations and dissolved organic matter (DOM). The reduction of As(V) (10-13%) and Fe(III) (12-17%) were partly in response to biochar abiotically causing desorption and reduction effect, but were predominantly (87-90% and 83-88% for As(V) and Fe(III)) attributed to biochar stimulating biological reduction. The level of As(III) released from sediment upon biochar amendment (656.35±89.25 μg L(-1)) was significantly higher than the level released without biochar amendment (98.06±19.38 μg L(-1)) after 49 days incubation. Although a low level of Fe(II) (0.81±0.07 mg L(-1)) was determined in the solution when amending with biochar, most of released Fe(II) (166.25±40.25 mg L(-1)) was formed as biochar-Fe(II)minerals composite. More importantly, biochar stimulated the DOM bioavailability in association with bacterial activities mediating As(V) and Fe(III) reduction. High-throughput sequencing results indicated biochar application shifted the soil microbial community and increased the relative abundance of As(V)-/Fe(III)-reducing bacteria, mostly Geobacter, Anaeromyxobacter, Desulfosporosinus and Pedobacter. The discovery of biochar-bacteria-DOM consortium may broaden new understanding into speciation and mobilization of metals, which arouses attention to exploit feasible bioremediation for metal-contaminated sediment. PMID:26954472