Science.gov

Sample records for anaerobic betaproteobacterium georgfuchsia

  1. Winter bloom of a rare betaproteobacterium in the Arctic Ocean.

    PubMed

    Alonso-Sáez, Laura; Zeder, Michael; Harding, Tommy; Pernthaler, Jakob; Lovejoy, Connie; Bertilsson, Stefan; Pedrós-Alió, Carlos

    2014-01-01

    Extremely low abundance microorganisms (members of the "rare biosphere") are believed to include dormant taxa, which can sporadically become abundant following environmental triggers. Yet, microbial transitions from rare to abundant have seldom been captured in situ, and it is uncertain how widespread these transitions are. A bloom of a single ribotype (≥99% similarity in the 16S ribosomal RNA gene) of a widespread betaproteobacterium (Janthinobacterium sp.) occurred over 2 weeks in Arctic marine waters. The Janthinobacterium population was not detected microscopically in situ in January and early February, but suddenly appeared in the water column thereafter, eventually accounting for up to 20% of bacterial cells in mid February. During the bloom, this bacterium was detected at open water sites up to 50 km apart, being abundant down to more than 300 m. This event is one of the largest monospecific bacterial blooms reported in polar oceans. It is also remarkable because Betaproteobacteria are typically found only in low abundance in marine environments. In particular, Janthinobacterium were known from non-marine habitats and had previously been detected only in the rare biosphere of seawater samples, including the polar oceans. The Arctic Janthinobacterium formed mucilagenous monolayer aggregates after short (ca. 8 h) incubations, suggesting that biofilm formation may play a role in maintaining rare bacteria in pelagic marine environments. The spontaneous mass occurrence of this opportunistic rare taxon in polar waters during the energy-limited season extends current knowledge of how and when microbial transitions between rare and abundant occur in the ocean. PMID:25191307

  2. Winter bloom of a rare betaproteobacterium in the Arctic Ocean

    PubMed Central

    Alonso-Sáez, Laura; Zeder, Michael; Harding, Tommy; Pernthaler, Jakob; Lovejoy, Connie; Bertilsson, Stefan; Pedrós-Alió, Carlos

    2014-01-01

    Extremely low abundance microorganisms (members of the “rare biosphere”) are believed to include dormant taxa, which can sporadically become abundant following environmental triggers. Yet, microbial transitions from rare to abundant have seldom been captured in situ, and it is uncertain how widespread these transitions are. A bloom of a single ribotype (≥99% similarity in the 16S ribosomal RNA gene) of a widespread betaproteobacterium (Janthinobacterium sp.) occurred over 2 weeks in Arctic marine waters. The Janthinobacterium population was not detected microscopically in situ in January and early February, but suddenly appeared in the water column thereafter, eventually accounting for up to 20% of bacterial cells in mid February. During the bloom, this bacterium was detected at open water sites up to 50 km apart, being abundant down to more than 300 m. This event is one of the largest monospecific bacterial blooms reported in polar oceans. It is also remarkable because Betaproteobacteria are typically found only in low abundance in marine environments. In particular, Janthinobacterium were known from non-marine habitats and had previously been detected only in the rare biosphere of seawater samples, including the polar oceans. The Arctic Janthinobacterium formed mucilagenous monolayer aggregates after short (ca. 8 h) incubations, suggesting that biofilm formation may play a role in maintaining rare bacteria in pelagic marine environments. The spontaneous mass occurrence of this opportunistic rare taxon in polar waters during the energy-limited season extends current knowledge of how and when microbial transitions between rare and abundant occur in the ocean. PMID:25191307

  3. Spatial Distribution of an Uranium-Respiring Betaproteobacterium at the Rifle, CO Field Research Site

    PubMed Central

    Koribanics, Nicole M.; Tuorto, Steven J.; Lopez-Chiaffarelli, Nora; McGuinness, Lora R.; Häggblom, Max M.; Williams, Kenneth H.; Long, Philip E.; Kerkhof, Lee J.

    2015-01-01

    The Department of Energy’s Integrated Field-Scale Subsurface Research Challenge Site (IFRC) at Rifle, Colorado was created to address the gaps in knowledge on the mechanisms and rates of U(VI) bioreduction in alluvial sediments. Previous studies at the Rifle IFRC have linked microbial processes to uranium immobilization during acetate amendment. Several key bacteria believed to be involved in radionuclide containment have been described; however, most of the evidence implicating uranium reduction with specific microbiota has been indirect. Here, we report on the cultivation of a microorganism from the Rifle IFRC that reduces uranium and appears to utilize it as a terminal electron acceptor for respiration with acetate as electron donor. Furthermore, this bacterium constitutes a significant proportion of the subsurface sediment community prior to biostimulation based on TRFLP profiling of 16S rRNA genes. 16S rRNA gene sequence analysis indicates that the microorganism is a betaproteobacterium with a high similarity to Burkholderia fungorum. This is, to our knowledge, the first report of a betaproteobacterium capable of uranium respiration. Our results indicate that this microorganism occurs commonly in alluvial sediments located between 3-6 m below ground surface at Rifle and may play a role in the initial reduction of uranium at the site. PMID:25874721

  4. Spatial distribution of an uranium-respiring betaproteobacterium at the Rifle, CO field research site.

    PubMed

    Koribanics, Nicole M; Tuorto, Steven J; Lopez-Chiaffarelli, Nora; McGuinness, Lora R; Häggblom, Max M; Williams, Kenneth H; Long, Philip E; Kerkhof, Lee J

    2015-01-01

    The Department of Energy's Integrated Field-Scale Subsurface Research Challenge Site (IFRC) at Rifle, Colorado was created to address the gaps in knowledge on the mechanisms and rates of U(VI) bioreduction in alluvial sediments. Previous studies at the Rifle IFRC have linked microbial processes to uranium immobilization during acetate amendment. Several key bacteria believed to be involved in radionuclide containment have been described; however, most of the evidence implicating uranium reduction with specific microbiota has been indirect. Here, we report on the cultivation of a microorganism from the Rifle IFRC that reduces uranium and appears to utilize it as a terminal electron acceptor for respiration with acetate as electron donor. Furthermore, this bacterium constitutes a significant proportion of the subsurface sediment community prior to biostimulation based on TRFLP profiling of 16S rRNA genes. 16S rRNA gene sequence analysis indicates that the microorganism is a betaproteobacterium with a high similarity to Burkholderia fungorum. This is, to our knowledge, the first report of a betaproteobacterium capable of uranium respiration. Our results indicate that this microorganism occurs commonly in alluvial sediments located between 3-6 m below ground surface at Rifle and may play a role in the initial reduction of uranium at the site. PMID:25874721

  5. Spatial distribution of an uranium-respiring betaproteobacterium at the Rifle, CO field research site

    DOE PAGESBeta

    Koribanics, Nicole M.; Tuorto, Steven J.; Lopez-Chiaffarelli, Nora; McGuinness, Lora R.; Häggblom, Max M.; Williams, Kenneth H.; Long, Philip E.; Kerkhof, Lee J.; Morais, Paula V

    2015-04-13

    The Department of Energy’s Integrated Field-Scale Subsurface Research Challenge Site (IFRC) at Rifle, Colorado was created to address the gaps in knowledge on the mechanisms and rates of U(VI) bioreduction in alluvial sediments. Previous studies at the Rifle IFRC have linked microbial processes to uranium immobilization during acetate amendment. Several key bacteria believed to be involved in radionuclide containment have been described; however, most of the evidence implicating uranium reduction with specific microbiota has been indirect. Here, we report on the cultivation of a microorganism from the Rifle IFRC that reduces uranium and appears to utilize it as a terminalmore » electron acceptor for respiration with acetate as electron donor. Furthermore, this bacterium constitutes a significant proportion of the subsurface sediment community prior to biostimulation based on TRFLP profiling of 16S rRNA genes. 16S rRNA gene sequence analysis indicates that the microorganism is a betaproteobacterium with a high similarity to Burkholderia fungorum. This is, to our knowledge, the first report of a betaproteobacterium capable of uranium respiration. Our results indicate that this microorganism occurs commonly in alluvial sediments located between 3-6 m below ground surface at Rifle and may play a role in the initial reduction of uranium at the site.« less

  6. Spatial distribution of an uranium-respiring betaproteobacterium at the Rifle, CO field research site

    SciTech Connect

    Koribanics, Nicole M.; Tuorto, Steven J.; Lopez-Chiaffarelli, Nora; McGuinness, Lora R.; Häggblom, Max M.; Williams, Kenneth H.; Long, Philip E.; Kerkhof, Lee J.; Morais, Paula V

    2015-04-13

    The Department of Energy’s Integrated Field-Scale Subsurface Research Challenge Site (IFRC) at Rifle, Colorado was created to address the gaps in knowledge on the mechanisms and rates of U(VI) bioreduction in alluvial sediments. Previous studies at the Rifle IFRC have linked microbial processes to uranium immobilization during acetate amendment. Several key bacteria believed to be involved in radionuclide containment have been described; however, most of the evidence implicating uranium reduction with specific microbiota has been indirect. Here, we report on the cultivation of a microorganism from the Rifle IFRC that reduces uranium and appears to utilize it as a terminal electron acceptor for respiration with acetate as electron donor. Furthermore, this bacterium constitutes a significant proportion of the subsurface sediment community prior to biostimulation based on TRFLP profiling of 16S rRNA genes. 16S rRNA gene sequence analysis indicates that the microorganism is a betaproteobacterium with a high similarity to Burkholderia fungorum. This is, to our knowledge, the first report of a betaproteobacterium capable of uranium respiration. Our results indicate that this microorganism occurs commonly in alluvial sediments located between 3-6 m below ground surface at Rifle and may play a role in the initial reduction of uranium at the site.

  7. Anaerobic Metabolism of Indoleacetate

    PubMed Central

    Ebenau-Jehle, Christa; Thomas, Markus; Scharf, Gernot; Kockelkorn, Daniel; Knapp, Bettina; Schühle, Karola; Heider, Johann

    2012-01-01

    The anaerobic metabolism of indoleacetate (indole-3-acetic acid [IAA]) in the denitrifying betaproteobacterium Azoarcus evansii was studied. The strain oxidized IAA completely and grew with a generation time of 10 h. Enzyme activities that transformed IAA were present in the soluble cell fraction of IAA-grown cells but were 10-fold downregulated in cells grown on 2-aminobenzoate or benzoate. The transformation of IAA did not require molecular oxygen but required electron acceptors like NAD+ or artificial dyes. The first products identified were the enol and keto forms of 2-oxo-IAA. Later, polar products were observed, which could not yet be identified. The first steps likely consist of the anaerobic hydroxylation of the N-heterocyclic pyrrole ring to the enol form of 2-oxo-IAA, which is catalyzed by a molybdenum cofactor-containing dehydrogenase. This step is probably followed by the hydrolytic ring opening of the keto form, which is catalyzed by a hydantoinase-like enzyme. A comparison of the proteome of IAA- and benzoate-grown cells identified IAA-induced proteins. Owing to the high similarity of A. evansii with strain EbN1, whose genome is known, we identified a cluster of 14 genes that code for IAA-induced proteins involved in the early steps of IAA metabolism. These genes include a molybdenum cofactor-dependent dehydrogenase of the xanthine oxidase/aldehyde dehydrogenase family, a hydantoinase, a coenzyme A (CoA) ligase, a CoA transferase, a coenzyme B12-dependent mutase, an acyl-CoA dehydrogenase, a fusion protein of an enoyl-CoA hydratase and a 3-hydroxyacyl-CoA dehydrogenase, a beta-ketothiolase, and a periplasmic substrate binding protein for ABC transport as well as a transcriptional regulator of the GntR family. Five predicted enzymes form or act on CoA thioesters, indicating that soon after the initial oxidation of IAA and possibly ring opening, CoA thioesters are formed, and the carbon skeleton is rearranged, followed by a CoA-dependent thiolytic

  8. Heterologous Expression of Polycyclic Aromatic Hydrocarbon Ring-Hydroxylating Dioxygenase Genes from a Novel Pyrene-Degrading Betaproteobacterium

    PubMed Central

    Hu, Jing; Aitken, Michael D.

    2012-01-01

    A betaproteobacterium within the family Rhodocyclaceae previously identified as a pyrene degrader via stable-isotope probing (SIP) of contaminated soil (designated pyrene group 1 or PG1) was cultivated as the dominant member of a mixed bacterial culture. A metagenomic library was constructed, and the largest contigs were analyzed for genes associated with polycyclic aromatic hydrocarbon (PAH) metabolism. Eight pairs of genes with similarity to the α- and β-subunits of ring-hydroxylating dioxygenases (RHDs) associated with aerobic bacterial PAH degradation were identified and linked to PG1 through PCR analyses of a simplified enrichment culture. In tandem with a ferredoxin and reductase found in close proximity to one pair of RHD genes, six of the RHDs were cloned and expressed in Escherichia coli. Each cloned RHD was tested for activity against nine PAHs ranging in size from two to five rings. Despite differences in their predicted protein sequences, each of the six RHDs was capable of transforming phenanthrene and pyrene. Three RHDs could additionally transform naphthalene and fluorene, and these genotypes were also associated with the ability of the E. coli constructs to convert indole to indigo. Only one of the six cloned RHDs was capable of transforming anthracene and benz[a]anthracene. None of the tested RHDs were capable of significantly transforming fluoranthene, chrysene, or benzo[a]pyrene. PMID:22427500

  9. Anaerobic bacteria

    MedlinePlus

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

  10. Characterization and genomic analysis of kraft lignin biodegradation by the beta-proteobacterium Cupriavidus basilensis B-8

    PubMed Central

    2013-01-01

    Background Lignin materials are abundant and among the most important potential sources for biofuel production. Development of an efficient lignin degradation process has considerable potential for the production of a variety of chemicals, including bioethanol. However, lignin degradation using current methods is inefficient. Given their immense environmental adaptability and biochemical versatility, bacterial could be used as a valuable tool for the rapid degradation of lignin. Kraft lignin (KL) is a polymer by-product of the pulp and paper industry resulting from alkaline sulfide treatment of lignocellulose, and it has been widely used for lignin-related studies. Results Beta-proteobacterium Cupriavidus basilensis B-8 isolated from erosive bamboo slips displayed substantial KL degradation capability. With initial concentrations of 0.5–6 g L-1, at least 31.3% KL could be degraded in 7 days. The maximum degradation rate was 44.4% at the initial concentration of 2 g L-1. The optimum pH and temperature for KL degradation were 7.0 and 30°C, respectively. Manganese peroxidase (MnP) and laccase (Lac) demonstrated their greatest level of activity, 1685.3 U L-1 and 815.6 U L-1, at the third and fourth days, respectively. Many small molecule intermediates were formed during the process of KL degradation, as determined using GC-MS analysis. In order to perform metabolic reconstruction of lignin degradation in this bacterium, a draft genome sequence for C. basilensis B-8 was generated. Genomic analysis focused on the catabolic potential of this bacterium against several lignin-derived compounds. These analyses together with sequence comparisons predicted the existence of three major metabolic pathways: β-ketoadipate, phenol degradation, and gentisate pathways. Conclusion These results confirmed the capability of C. basilensis B-8 to promote KL degradation. Whole genomic sequencing and systematic analysis of the C. basilensis B-8 genome identified degradation steps and

  11. Anaerobic bacteria

    MedlinePlus

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

  12. Anaerobic Process.

    PubMed

    Li, Wei-Zun; Qian, Yang; Chang, Chein-Chi; Ju, Meiting

    2015-10-01

    A review of the literature published in 2014 on the focus of Anaerobic Process. It is divided into the following sections. •Pretreatment •Organic waste •multiple-stage co-digestion •Process Methodology and Technology. PMID:26420080

  13. Combined use of flow cytometry and microscopy to study the interactions between the gram-negative betaproteobacterium Acidovorax facilis and uranium(VI).

    PubMed

    Gerber, U; Zirnstein, I; Krawczyk-Bärsch, E; Lünsdorf, H; Arnold, T; Merroun, M L

    2016-11-01

    The former uranium mine Königstein (Saxony, Germany) is currently in the process of remediation by means of controlled underground flooding. Nevertheless, the flooding water has to be cleaned up by a conventional wastewater treatment plant. In this study, the uranium(VI) removal and tolerance mechanisms of the gram-negative betaproteobacterium Acidovorax facilis were investigated by a multidisciplinary approach combining wet chemistry, flow cytometry, and microscopy. The kinetics of uranium removal and the corresponding mechanisms were investigated. The results showed a biphasic process of uranium removal characterized by a first phase where 95% of uranium was removed within the first 8h followed by a second phase that reached equilibrium after 24h. The bacterial cells displayed a total uranium removal capacity of 130mgU/g dry biomass. The removal of uranium was also temperature-dependent, indicating that metabolic activity heavily influenced bacterial interactions with uranium. TEM analyses showed biosorption on the cell surface and intracellular accumulation of uranium. Uranium tolerance tests showed that A. facilis was able to withstand concentrations up to 0.1mM. This work demonstrates that A. facilis is a suitable candidate for in situ bioremediation of flooding water in Königstein as well as for other contaminated waste waters. PMID:27262280

  14. Anaerobic sealing

    SciTech Connect

    Hayre, J.

    1986-05-01

    Anaerobic sealants offer an alternative to conventional methods of joint repair on mains operating at low and medium pressures. The method does not require highly skilled personnel who are diligent in ensuring that the necessary standards of preparation and seal application are achieved. British Gas' experience has shown that lead joints that do not contain yarn or where the yarn has deteriorated are difficult to seal. The evidence so far indicates that yarn is important in ensuring that the low viscosity sealant rapidly wicks around the joint during the injection operation. It is obvious that more research and development is needed in this field, but anaerobic sealing of leaking joints in an effective, innovative method of joint repair.

  15. Anaerobic Thermophiles

    PubMed Central

    Canganella, Francesco; Wiegel, Juergen

    2014-01-01

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

  16. Anaerobic thermophiles.

    PubMed

    Canganella, Francesco; Wiegel, Juergen

    2014-01-01

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

  17. The genome sequence of the obligately chemolithoautotrophic, facultatively anaerobic bacterium Thiobacillus denitfificans.

    SciTech Connect

    Beller, H R; Larimer, Frank W

    2006-02-01

    The complete genome sequence of Thiobacillus denitrificans ATCC 25259 is the first to become available for an obligately chemolithoautotrophic, sulfur-compound-oxidizing, {beta}-proteobacterium. Analysis of the 2,909,809-bp genome will facilitate our molecular and biochemical understanding of the unusual metabolic repertoire of this bacterium, including its ability to couple denitrification to sulfur-compound oxidation, to catalyze anaerobic, nitrate-dependent oxidation of Fe(II) and U(IV), and to oxidize mineral electron donors. Notable genomic features include (i) genes encoding c-type cytochromes totaling 1 to 2 percent of the genome, which is a proportion greater than for almost all bacterial and archaeal species sequenced to date, (ii) genes encoding two [NiFe]hydrogenases, which is particularly significant because no information on hydrogenases has previously been reported for T. denitrificans and hydrogen oxidation appears to be critical for anaerobic U(IV) oxidation by this species, (iii) a diverse complement of more than 50 genes associated with sulfur-compound oxidation (including sox genes, dsr genes, and genes associated with the AMP-dependent oxidation of sulfite to sulfate), some of which occur in multiple (up to eight) copies, (iv) a relatively large number of genes associated with inorganic ion transport and heavy metal resistance, and (v) a paucity of genes encoding organic-compound transporters, commensurate with obligate chemolithoautotrophy. Ultimately, the genome sequence of T. denitrificans will enable elucidation of the mechanisms of aerobic and anaerobic sulfur-compound oxidation by {beta}-proteobacteria and will help reveal the molecular basis of this organism's role in major biogeochemical cycles (i.e., those involving sulfur, nitrogen, and carbon) and groundwater restoration.

  18. Anaerobic bag culture method.

    PubMed

    Rosenblatt, J E; Stewart, P R

    1975-06-01

    In a new method of anaerobic culture, a transparent, gas-impermeable bag is used and the anaerobic environment is established with copper sulfate-saturated steel wool. An Alka-Seltzer tablet generates carbon dioxide. The agar plate surface can be inspected through the bag at any time without interrupting the anaerobic atmosphere or disturbing other specimens. Methylene blue indicator strips are completely reduced by 4 h after the bag is set up and have remained reduced for as long as 3 weeks. Growth of 16 different stock culture anaerobes was generally equivalent by the bag and GasPak jar methods. Yield and growth of anaerobic isolates also were equivalent with 7 of 10 clinical specimens; from the other 3 specimens, 13 isolates were recovered, 5 by both the bag and jar methods and the rest by one method or the other. No consistent differences were found between the anaerobic bag and GasPak jar methods in the yield of anaerobes from clinical specimens. Early growth (24 h of incubation) of anaerobes from one specimen was detected with the bag method. PMID:1100671

  19. Anaerobic bag culture method.

    PubMed Central

    Rosenblatt, J E; Stewart, P R

    1975-01-01

    In a new method of anaerobic culture, a transparent, gas-impermeable bag is used and the anaerobic environment is established with copper sulfate-saturated steel wool. An Alka-Seltzer tablet generates carbon dioxide. The agar plate surface can be inspected through the bag at any time without interrupting the anaerobic atmosphere or disturbing other specimens. Methylene blue indicator strips are completely reduced by 4 h after the bag is set up and have remained reduced for as long as 3 weeks. Growth of 16 different stock culture anaerobes was generally equivalent by the bag and GasPak jar methods. Yield and growth of anaerobic isolates also were equivalent with 7 of 10 clinical specimens; from the other 3 specimens, 13 isolates were recovered, 5 by both the bag and jar methods and the rest by one method or the other. No consistent differences were found between the anaerobic bag and GasPak jar methods in the yield of anaerobes from clinical specimens. Early growth (24 h of incubation) of anaerobes from one specimen was detected with the bag method. Images PMID:1100671

  20. Anaerobic thermophilic culture

    DOEpatents

    Ljungdahl, Lars G.; Wiegel, Jurgen K. W.

    1981-01-01

    A newly discovered thermophilic anaerobe is described that was isolated in a biologically pure culture and designated Thermoanaerobacter ethanolicus ATCC 3/550. T. Ethanolicus is cultured in aqueous nutrient medium under anaerobic, thermophilic conditions and is used in a novel process for producing ethanol by subjecting carbohydrates, particularly the saccharides, to fermentation action of the new microorganism in a biologically pure culture.

  1. Anaerobic specimen transport device.

    PubMed Central

    Wilkins, T D; Jimenez-Ulate, F

    1975-01-01

    A device is described and evaluated for the anaerobic transport of clinical specimens. The device limits the amount of oxygen entering with the sample to a maximum of 2%, which is rapidly removed by reacting with hydrogen in the presence of a palladium catalyst. The viability on swabs of 12 species of anaerobes, four strains of facultative anaerobes and a strain of Pseudomonas aeruginosa, was maintained during the length of the tests (24 or 48 h). The results demonstrated that this device protected even the more oxygen-sensitive clinical anaerobes from death due to oxygen exposure. This device can be used for swabs as well as for anaerobic collection and liquid and solid specimens. Images PMID:1104656

  2. Anaerobic Digestion and its Applications

    EPA Science Inventory

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

  3. Membrane controlled anaerobic digestion

    NASA Astrophysics Data System (ADS)

    Omstead, D. R.

    In response to general shortages of energy, examination of the anaerboic digestion process as a potential source of a combustible, methane-rich fuel has intensified in recent years. It has been suggested that orgaic intermediates (such as fatty acids), produced during digestion, might also be recovered for use as chemical feedstocks. This investigation has been concerned with combining ultrafiltration separation techniques with anaerobic digestion for the development of a process in which the total production of acetic acid (the most valuable intermediate in anaerobic digestion) and methane are optimized. Enrichment cultures, able to utilize glucose as a sole carbon source, were adapted from sewage digesting cultures using conventional techniques. An ultrafiltration system was constructed and coupled to an anaerobic digester culture vessel which contained the glucose enrichment. The membrane controlled anaerobic digester appears to show promise as a means of producing high rates of both methane gas and acetic acid.

  4. Anaerobic brain abscess

    PubMed Central

    Sudhaharan, Sukanya; Chavali, Padmasri

    2016-01-01

    Background and Objectives: Brain abscess remains a potentially fatal central nervous system (CNS) disease, especially in developing countries. Anaerobic abscess is difficult to diagnose because of cumbersome procedures associated with the isolation of anaerobes. Materials and Methods: This is a hospital-based retrospective microbiological analysis of 430 brain abscess materials (purulent aspirates and/or tissue), for anaerobic organisms, that were received between 1987–2014, by the Microbiology Laboratory in our Institute. Results: Culture showed growth of bacteria 116/430 (27%) of the cases of which anaerobes were isolated in 48/116 (41.1%) of the cases. Peptostreptococcus (51.4 %), was the predominant organism isolated in four cases followed by Bacteroides and Peptococcus species. Conclusion: Early diagnosis and detection of these organisms would help in the appropriate management of these patients. PMID:27307977

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

    PubMed Central

    Maud, P J; Shultz, B B

    1986-01-01

    The purpose of the study was to compare anaerobic power and anaerobic capacity test scores between young active men and women. Three performance measures of anaerobic power and two of anaerobic capacity were administered to a sample comprising 52 male and 50 female college students (means age = 21.4 yrs). Results indicated significant differences between men and women in body height, weight and per cent fat, in fat free mass (FFM), anaerobic power, and anaerobic capacity when recorded as gross work completed and relative to body weight. However, these differences are reduced when data is adjusted for body weight and further reduced when corrected for FFM. The study found no significant differences between men and women in either anaerobic power or anaerobic capacity when values were given relative to FFM. PMID:3730753

  6. THERMOPHILIC ANAEROBIC BIODEGRADATION OF PHENOLICS

    EPA Science Inventory

    The report gives results of a series of anaerobic microbial acclimation and treatment performance tests with synthetic phenolic substrates. The research is a feasibility level assessment of substituting anaerobic biodegradation of phenolics for solvent extraction. The tests showe...

  7. The anaerobic digestion process

    SciTech Connect

    Rivard, C.J.; Boone, D.R.

    1996-01-01

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

  8. Anaerobic thermophilic culture system

    DOEpatents

    Ljungdahl, Lars G.; Wiegel, Jurgen K. W.

    1981-01-01

    A mixed culture system of the newly discovered microorganism Thermoanaerobacter ethanolicus ATCC31550 and the microorganism Clostridium thermocellum ATCC31549 is described. In a mixed nutrient culture medium that contains cellulose, these microorganisms have been coupled and cultivated to efficiently ferment cellulose to produce recoverable quantities of ethanol under anaerobic, thermophilic conditions.

  9. Simultaneous Involvement of a Tungsten-Containing Aldehyde:Ferredoxin Oxidoreductase and a Phenylacetaldehyde Dehydrogenase in Anaerobic Phenylalanine Metabolism

    PubMed Central

    Debnar-Daumler, Carlotta; Seubert, Andreas; Schmitt, Georg

    2014-01-01

    Anaerobic phenylalanine metabolism in the denitrifying betaproteobacterium Aromatoleum aromaticum is initiated by conversion of phenylalanine to phenylacetate, which is further metabolized via benzoyl-coenzyme A (CoA). The formation of phenylacetate is catalyzed by phenylalanine transaminase, phenylpyruvate decarboxylase, and a phenylacetaldehyde-oxidizing enzyme. The presence of these enzymes was detected in extracts of cells grown with phenylalanine and nitrate. We found that two distinct enzymes are involved in the oxidation of phenylacetaldehyde to phenylacetate, an aldehyde:ferredoxin oxidoreductase (AOR) and a phenylacetaldehyde dehydrogenase (PDH). Based on sequence comparison, growth studies with various tungstate concentrations, and metal analysis of the enriched enzyme, AOR was shown to be a tungsten-containing enzyme, necessitating specific cofactor biosynthetic pathways for molybdenum- and tungsten-dependent enzymes simultaneously. We predict from the genome sequence that most enzymes of molybdopterin biosynthesis are shared, while the molybdate/tungstate uptake systems are duplicated and specialized paralogs of the sulfur-inserting MoaD and the metal-inserting MoeA proteins seem to be involved in dedicating biosynthesis toward molybdenum or tungsten cofactors. We also characterized PDH biochemically and identified both NAD+ and NADP+ as electron acceptors. We identified the gene coding for the enzyme and purified a recombinant Strep-tagged PDH variant. The homotetrameric enzyme is highly specific for phenylacetaldehyde, has cooperative kinetics toward the substrate, and shows considerable substrate inhibition. Our data suggest that A. aromaticum utilizes PDH as the primary enzyme during anaerobic phenylalanine degradation, whereas AOR is not essential for the metabolic pathway. We hypothesize a function as a detoxifying enzyme if high aldehyde concentrations accumulate in the cytoplasm, which would lead to substrate inhibition of PDH. PMID:24214948

  10. Antimicrobials therapy of anaerobic infections.

    PubMed

    Brook, Itzhak

    2016-06-01

    Anaerobes predominant in the normal human skin and mucous membranes bacterial flora are often a cause of endogenous infections. Anaerobic bacteria are difficult to isolate from infectious sites, and are often overlooked. Anaerobic infections caused by anaerobes can occur in all body sites, including the central nervous system (CNS), oral cavity, head and neck, chest, abdomen, pelvis, skin and soft tissues. The treatment of these infections is complicated by the slow growth of these organisms, their polymicrobial nature and the growing resistance of anaerobes to antimicrobials agents. Antimicrobials are frequently the only form of therapy needed, but in others, they are an important adjunct to surgical drainage and correction of pathology. Because anaerobes are often recovered with aerobic and facultative bacteria, the chosen antimicrobials should cover all pathogens. The antimicrobials effective against anaerobic organisms are metronidazole, carbapenems, combinations of a beta-lactam and a beta-lactamase inhibitor, chloramphenicol, tigecycline and clindamycin. PMID:26365224

  11. Anaerobic transformation of TNT

    SciTech Connect

    Kulpa, C.F.; Roopathy, R.

    1995-12-31

    Most studies on the microbial metabolism of nitroaromatic compounds have used aerobic tempts to degrade nitroaromatics under aerobic microorganisms. In many cases attempts to degrade nitroaromatics under aerobic conditions results in no mineralization and only superficial modifications of the structure. However, under anaerobic sulfate-reducing conditions, the nitroaromatic compounds undergo a series of reductions with the formation of amino compounds. Trinitrotoluene 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 nitrate from trinitrotoluene is achieved by a series of reductive reactions with the production of ammonia and toluene by Desulfovibrio sp. (B strain). Similar metabolic processes could be applied to other nitroaromatic compounds like nitrobenzene, nitrobenzoic acids, nitrophenols, and aniline. This presentation will review the data supporting the anaerobic transformation of TNT and other nitroaromatics.

  12. Anaerobic lung infections.

    PubMed

    Vincent, M T; Goldman, B S

    1994-06-01

    Aspiration is the leading cause of anaerobic lung infections. Risk factors for these infections include a depressed level of consciousness, a history of seizure, general anesthesia, central nervous system or neuromuscular disease, cerebrovascular accident, impaired swallowing and use of a tracheal or nasogastric tube. Clinical presentation includes fever, weight loss, malaise and cough productive of foul-smelling sputum. Diagnosis is based on radiographic findings, clinical features and a characteristic morphology of mixed flora on Gram stain of uncontaminated pulmonary specimens. The diagnosis is confirmed by isolation of organisms, usually polymicrobial, on culture. Treatment includes proper drainage, debridement of necrotic tissue and an antibiotic regimen (often initially empiric) with an agent active against anaerobic and aerobic organisms. PMID:8203319

  13. Anaerobic digestion process

    SciTech Connect

    Ishida, M.; Haga, R.; Odawara, Y.

    1982-10-19

    An algae culture grown on the water from the digested slurry of a biogasification plant serves as a means of removing CO/sub 2/ from the methane stream while purifying the wastewater and providing more biomass for the anaerobic digestion plant. Tested on a sewage-sludge digestion system, the proposed process improved the methane yield by 32% and methane concentration by 53-98 vol % while lowering the concentration of nitrogen and phosphorus in the final water.

  14. Anaerobic wastewater treatment using anaerobic baffled bioreactor: a review

    NASA Astrophysics Data System (ADS)

    Hassan, Siti Roshayu; Dahlan, Irvan

    2013-09-01

    Anaerobic wastewater treatment is receiving renewed interest because it offers a means to treat wastewater with lower energy investment. Because the microorganisms involved grow more slowly, such systems require clever design so that the microbes have sufficient time with the substrate to complete treatment without requiring enormous reactor volumes. The anaerobic baffled reactor has inherent advantages over single compartment reactors due to its circulation pattern that approaches a plug flow reactor. The physical configuration of the anaerobic baffled reactor enables significant modifications to be made; resulting in a reactor which is proficient of treating complex wastewaters which presently require only one unit, ultimately significant reducing capital costs. This paper also concerns about mechanism, kinetic and hydrodynamic studies of anaerobic digestion for future application of the anaerobic baffled reactor for wastewater treatment.

  15. Physiology of deletion mutants in the anaerobic β-myrcene degradation pathway in Castellaniella defragrans

    PubMed Central

    2012-01-01

    Background Monoterpenes present a large and versatile group of unsaturated hydrocarbons of plant origin with widespread use in the fragrance as well as food industry. The anaerobic β-myrcene degradation pathway in Castellaniella defragrans strain 65Phen differs from well known aerobic, monooxygenase-containing pathways. The initial enzyme linalool dehydratase-isomerase ldi/LDI catalyzes the hydration of β-myrcene to (S)-(+)-linalool and its isomerization to geraniol. A high-affinity geraniol dehydrogenase geoA/GeDH and a geranial dehydrogenase geoB/GaDH contribute to the formation of geranic acid. A genetic system was for the first time applied for the betaproteobacterium to prove in vivo the relevance of the linalool dehydratase-isomerase and the geraniol dehydrogenase. In-frame deletion cassettes were introduced by conjugation and two homologous recombination events. Results Polar effects were absent in the in-frame deletion mutants C. defragrans Δldi and C. defragrans ΔgeoA. The physiological characterization of the strains demonstrated a requirement of the linalool dehydratase-isomerase for growth on acyclic monoterpenes, but not on cyclic monoterpenes. The deletion of geoA resulted in a phenotype with hampered growth rate on monoterpenes as sole carbon and energy source as well as reduced biomass yields. Enzyme assays revealed the presence of a second geraniol dehydrogenase. The deletion mutants were in trans complemented with the broad-host range expression vector pBBR1MCS-4ldi and pBBR1MCS-2geoA, restoring in both cases the wild type phenotype. Conclusions In-frame deletion mutants of genes in the anaerobic β-myrcene degradation revealed novel insights in the in vivo function. The deletion of a high-affinity geraniol dehydrogenase hampered, but did not preclude growth on monoterpenes. A second geraniol dehydrogenase activity was present that contributes to the β-myrcene degradation pathway. Growth on cyclic monoterpenes independent of the initial

  16. Economic viability of anaerobic digestion

    SciTech Connect

    Wellinger, A.

    1996-01-01

    The industrial application of anaerobic digestion is a relatively new, yet proven waste treatment technology. Anaerobic digestion reduces and upgrades organic waste, and is a good way to control air pollution as it reduces methane and nitrous gas emissions. For environmental and energy considerations, anaerobic digestion is a nearly perfect waste treatment process. However, its economic viability is still in question. A number of parameters - type of waste (solid or liquid), digester system, facility size, product quality and end use, environmental requirements, cost of alternative treatments (including labor), and interest rates - define the investment and operating costs of an anaerobic digestion facility. Therefore, identical facilities that treat the same amount and type of waste may, depending on location, legislation, and end product characteristics, reveal radically different costs. A good approach for evaluating the economics of anaerobic digestion is to compare it to treatment techniques such as aeration or conventional sewage treatment (for industrial wastewater), or composting and incineration (for solid organic waste). For example, the cost (per ton of waste) of in-vessel composting with biofilters is somewhat higher than that of anaerobic digestion, but the investment costs 1 1/2 to 2 times more than either composting or anaerobic digestion. Two distinct advantages of anaerobic digestion are: (1) it requires less land than either composting or incinerating, which translates into lower costs and milder environmental and community impacts (especially in densely populated areas); and (2) it produces net energy, which can be used to operate the facility or sold to nearby industries.

  17. Diversity of anaerobic halophilic microorganisms

    NASA Astrophysics Data System (ADS)

    Oren, Aharon; Oremland, Roland S.

    2000-12-01

    Life in the presence of high salt concentrations is compatible with life in the absence of oxygen. Halophilic and halotolerant anaerobic prokaryotes are found both in the archaeal and in the bacterial domain, and they display a great metabolic diversity. Many of the representatives of the Halobacteriales (Archaea), which are generally considered aerobes, have the potential of anaerobic growth. Some can use alternative electron acceptors such as nitrate, fumarate, dimethylsulfoxide or trimethylamine-N-oxide Halobacterium salinarum can also grow fermentatively on L-arginine, and bacteriorhodopsin-containing cells may even grow anaerobically, energized by light. Obligatory anaerobic halophilic methanogenic Archaea also exist. The bacterial domain contains many anaerobic halophiles, including sulfate reducers. There is also a group of specialized obligatory anaerobic Bacteria, phylogenetically clustering in the low G + C branch of the Firmicutes. Most representatives of this group (order Haloanaerobiales, families Haloanaerobiaceae and Halobacteroidaceae) are fermentative, using a variety of carbohydrates and amino acids. One species combines the potential for anaerobic growth at high salt concentrations with a preference for high temperatures. Others are homoacetogens; Acetohalobium arabaticum can grow anaerobically as a chemolithotroph, producing acetate from hydrogen and CO2. The Haloanaerobiales accumulate high concentrations of K+ and Cl- in their cytoplasm, thereby showing a strategy of salt adaptation similar to that used by the Halobacteriales. Recently a new representative of the Haloanaerobiales was isolated from bottom sediments of the Dead Sea (strain DSSe1), which grows anaerobically by oxidation of glycerol to acetate and CO2 while reducing selenate to selenite and elementary selenium. Other electron acceptors supporting anaerobic growth of this strain are nitrate and trimethylamine-N-oxide. The versatility of life at high salt concentrations with respect

  18. Arsenic, Anaerobes, and Autotrophy.

    NASA Astrophysics Data System (ADS)

    Oremland, R. S.

    2008-12-01

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

  19. Cefamandole Therapy in Anaerobic Infections

    PubMed Central

    Greenberg, Richard N.; Scalcini, Marcella C.; Sanders, Charles V.; Lewis, A. Carter

    1979-01-01

    Thirty-one adult patients with infections due to anaerobic bacteria were treated with cefamandole. Bacteroides fragilis group (17) and Bacteroides melaninogenicus (13) were the most frequent anaerobes isolated. Duration of therapy varied from 2 to 49 days. Results were judged satisfactory in 26 cases, and unsatisfactory in 1 case. Four cases could not be evaluated. Adverse reactions occurred in 16 patients and included positive direct Coombs' test without hemolysis, transient liver function abnormalities, phlebitis, reversible neutropenia, fever, eosinophilia, and toxic epidermal necrolysis. The more significant reactions were associated with prolonged therapy. None was lethal. These data suggest that cefamandole is effective in treatment of most anaerobic infections. PMID:380458

  20. PCB breakdown by anaerobic microorganisms

    SciTech Connect

    Not Available

    1989-03-01

    Recently, altered PCB cogener distribution patterns observed in anaerobic sediment samples from the upper Hudson River are being attributed to biologically mediated reductive dechlorination. The authors report their successful demonstration of biologically mediated reductive dechlorination of an Aroclor mixture. In their investigation, they assessed the ability of microorganisms from PCB-contaminated Hudson River sediments (60-562 ppm PCBs) to dechlorinate Aroclor 1242 under anaerobic conditions by eluting microorganisms from the PCB- contaminated sediments and transferring them to a slurry of reduced anaerobic mineral medium and PCB-free sediments in tightly stoppered bottles. They observed dechlorination to be the most rapid at the highest PCB concentration tried by them.

  1. Parotitis due to anaerobic bacteria.

    PubMed

    Matlow, A; Korentager, R; Keystone, E; Bohnen, J

    1988-01-01

    Although Staphylococcus aureus remains the pathogen most commonly implicated in acute suppurative parotitis, the pathogenic role of gram-negative facultative anaerobic bacteria and strict anaerobic organisms in this disease is becoming increasingly recognized. This report describes a case of parotitis due to Bacteroides disiens in an elderly woman with Sjögren's syndrome. Literature reports on seven additional cases of suppurative parotitis due to anaerobic bacteria are reviewed. Initial therapy of acute suppurative parotitis should include coverage for S. aureus and, in a very ill patient, coverage of gram-negative facultative organisms with antibiotics such as cloxacillin and an aminoglycoside. A failure to respond clinically to such a regimen or isolation of anaerobic bacteria should lead to the consideration of the addition of clindamycin or penicillin. PMID:3287567

  2. Dance--Aerobic and Anaerobic.

    ERIC Educational Resources Information Center

    Cohen, Arlette

    1984-01-01

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

  3. Bioenergy from anaerobically treated wastewater

    SciTech Connect

    Richards, E.A.

    1981-01-01

    Breweries and other processing plants including dairy cooperatives, sugar plants, grain mills, gasohol plants, etc., produce wastewater containing complex organic matter, either in solution or as volatile suspended solids, which can be treated anaerobically to effectively reduce the pollutants by 85-95% and generate a CH4 containing gas. An example anaerobic plant to serve a 10 to the power of 6-bbl brewery is discussed.

  4. PILOT ANAEROBIC BIOLOGICAL TREATMENT OF PULP MILL EVAPORATOR FOUL CONDENSATE

    EPA Science Inventory

    The performance of three new anaerobic biological treatment technologies were compared and evaluated. Data were obtained from the operation of pilot plants representative of the anaerobic filter, anaerobic upflow sludge bed, and anaerobic fluidized bed. A review of recent literat...

  5. The Transition from Aerobic to Anaerobic Metabolism.

    ERIC Educational Resources Information Center

    Skinner, James S.; McLellan, Thomas H.

    1980-01-01

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

  6. Arsenic, Anaerobes, and Astrobiology

    NASA Astrophysics Data System (ADS)

    Stolz, J. F.; Oremland, R. S.; Switzer Blum, J.; Hoeft, S. E.; Baesman, S. M.; Bennett, S.; Miller, L. G.; Kulp, T. R.; Saltikov, C.

    2013-12-01

    Arsenic is an element best known for its highly poisonous nature, so it is not something one would associate with being a well-spring for life. Yet discoveries made over the past two decades have delineated that not only are some microbes resistant to arsenic, but that this element's primary redox states can be exploited to conserve energy and support prokaryotic growth ('arsenotrophy') in the absence of oxygen. Hence, arsenite [As(III)] can serve as an electron donor for chemo- or photo-autotrophy while arsenate [As(V)] will serve as an electron acceptor for chemo-heterotrophs and chemo-autotrophs. The phylogenetic diversity of these microbes is broad, encompassing many individual species from diverse taxonomic groups in the Domain Bacteria, with fewer representatives in the Domain Archaea. Speculation with regard to the evolutionary origins of the key functional genes in anaerobic arsenic transformations (arrA and arxA) and aerobic oxidation (aioB) has led to a disputation as to which gene and function is the most ancient and whether arsenic metabolism extended back into the Archaean. Regardless of its origin, robust arsenic metabolism has been documented in extreme environments that are rich in their arsenic content, such as hot springs and especially hypersaline soda lakes associated with volcanic regions. Searles Lake, CA is an extreme, salt-saturated end member where vigorous arsenic metabolism occurs, but there is no detectable sulfate-reduction or methanogenesis. The latter processes are too weak bio-energetically to survive as compared with arsenotrophy, and are also highly sensitive to the abundance of borate ions present in these locales. These observations have implications with respect to the search for microbial life elsewhere in the Solar System where volcanic-like processes have been operative. Hence, because of the likelihood of encountering dense brines in the regolith of Mars (formed by evapo-concentration) or beneath the ice layers of Europa

  7. Anaerobic bioprocessing of organic wastes.

    PubMed

    Verstraete, W; de Beer, D; Pena, M; Lettinga, G; Lens, P

    1996-05-01

    Anaerobic digestion of dissolved, suspended and solid organics has rapidly evolved in the last decades but nevertheless still faces several scientific unknowns. In this review, some fundamentals of bacterial conversions and adhesion are addressed initially. It is argued in the light of ΔG-values of reactions, and in view of the minimum energy quantum per mol, that anaerobic syntrophs must have special survival strategies in order to support their existence: redistributing the available energy between the partners, reduced end-product fermentation reactions and special cell-to-cell physiological interactions. In terms of kinetics, it appears that both reaction rates and residual substrate thresholds are strongly related to minimum ΔG-values. These new fundamental insights open perspectives for efficient design and operation of anaerobic bioprocesses. Subsequently, an overview is given of the current anaerobic biotechnology. For treating wastewaters, a novel and high performance new system has been introduced during the last decade; the upflow anaerobic sludge blanket system (UASB). This reactor concept requires anaerobic consortia to grow in a dense and eco-physiologically well-organized way. The microbial principles of such granular sludge growth are presented. Using a thermodynamic approach, the formation of different types of aggregates is explained. The application of this bioprocess in worldwide wastewater treatment is indicated. Due to the long retention times of the active biomass, the UASB is also suitable for the development of bacterial consortia capable of degrading xenobiotics. Operating granular sludge reactors at high upflow velocities (5-6 m/h) in expanded granular sludge bed (EGSB) systems enlarges the application field to very low strength wastewaters (chemical oxygen demand < 1 g/l) and psychrophilic temperatures (10°C). For the treatment of organic suspensions, there is currently a tendency to evolve from the conventional mesophilic

  8. Processing anaerobic sludge for extended storage as anaerobic digester inoculum.

    PubMed

    Li, Jiajia; Zicari, Steven M; Cui, Zongjun; Zhang, Ruihong

    2014-08-01

    Thermophilic anaerobic sludge was processed to reduce the volume and moisture content in order to reduce costs for storing and transporting the sludge as microbial inoculum for anaerobic digester startup. The moisture content of the sludge was reduced from 98.7% to 82.0% via centrifugation and further to 71.5% via vacuum evaporation. The processed sludge was stored for 2 and 4 months and compared with the fresh sludge for the biogas and methane production using food waste and non-fat dry milk as substrates. It was found that fresh unprocessed sludge had the highest methane yield and the yields of both unprocessed and processed sludges decreased during storage by 1-34%, however processed sludges seemed to regain some activity after 4 months of storage as compared to samples stored for only 2 months. Maximum methane production rates obtained from modified Gompertz model application also increased between the 2-month and 4-month processed samples. PMID:24907580

  9. Anaerobic degradation of monoazo dyes

    SciTech Connect

    Kremer, F.V.

    1989-01-01

    The anaerobic degradation of two monoazo dyes, acid red 88 (AR88) and acid orange 7, was studied utilizing serum bottle assays. When either dye was present between .05 and 50 mg/L as the sole substrate, inhibition was demonstrated, with no mineralization occurring. However, when a supplemental carbon and energy source was available no inhibition was evidence with mineralization occurring at intermediate concentrations. The degradation of AR88 and metabolite formation was examined utilizing laboratory-scale semi-continuous anaerobic reactors. Addition of 50 mg/L of dye resulted in >98% removal, although mineralization was not achieved. Metabolites identified were naphthionic acid, 2-naphthol, 1,2-naphthoquinone, isoquinoline, and quinacridone. The presence of the metabolites, some of which were products of complexation and polymerization, exerted a slight inhibitory effect on the non-methanogens. The availability of a supplemental carbon source demonstrated an effect on the metabolites that are evolved and the rate at which they are formed.

  10. Anaerobic digestion of brewery byproducts

    SciTech Connect

    Keenan, J.D.; Kormi, I.

    1981-01-01

    Energy recovery in the brewery industry by mesophilic anaerobic digesion of process by-products is technically feasible. The maximum achievable loading rate is 6g dry substrate/L-day. CH4 gas production declines as the loading rate increases in the range 2-6 g/L day. CH4 production increases in the range 8-15 days; optimal design criteria are a 10-day detention time with a loading rate of 6 g dry substrate/L day.

  11. Anaerobic digestion of aliphatic polyesters.

    PubMed

    Šmejkalová, Pavla; Kužníková, Veronika; Merna, Jan; Hermanová, Soňa

    2016-01-01

    Anaerobic processes for the treatment of plastic materials waste represent versatile and effective approach in environmental protection and solid waste management. In this work, anaerobic biodegradability of model aliphatic polyesters, poly(L-lactic acid) (PLA), and poly(ɛ-caprolactone) (PCL), in the form of powder and melt-pressed films with varying molar mass, was studied. Biogas production was explored in batch laboratory trials at 55 ± 1°C under a nitrogen atmosphere. The inoculum used was thermophilic digested sludge (total solids concentration of 2.9%) from operating digesters at the Central Waste Water Treatment Plant in Prague, Czech Republic. Methanogenic biodegradation of PCLs typically yielded from 54 to 60% of the theoretical biogas yield. The biodegradability of PLAs achieved from 56 to 84% of the theoretical value. High biogas yield (up to 677 mL/g TS) with high methane content (more than 60%), comparable with conventionally processed materials, confirmed the potential of polyester samples for anaerobic treatment in the case of their exploitation in agriculture or as a packaging material in the food industry. PMID:27191559

  12. Anaerobic infections in children: a prospective survey.

    PubMed Central

    Thirumoorthi, M C; Keen, B M; Dajani, A S

    1976-01-01

    Over an 18-month period, cultures from 95 infants and children yielded 146 anaerobic organisms in 110 clinical specimens. Bacteroides was the most frequently isolated anaerobe, followed by Propionibacterium and Clostridium species. Intra-abdominal sources, soft tissues, and blood were the three major sources (82%) of isolation of anaerobes. Whereas most patients (58%) were over 5 years of age and only 11% were newborns, anaerobic infections constituted a rather uniform proportion of all infections, regardless of sources, in all age groups. Anaerobes accounted for only 2.9% of all positive cultures encountered from the various sources. Rates of recovery of anaerobes from intra-abdominal sources were significantly the highest, and from soft-tissue infections they were significantly the lowest. The anaerobic bacteremias observed were of no clinical significance when Propionibacterium species were isolated; however, recovery of other anaerobes from the blood, and primarily Bacteroides species, was usually associated with clinical disease. Except in blood cultures, anaerobes almost invariably coexisted with facultative bacteria. PMID:1270594

  13. Basic Laboratory Culture Methods for Anaerobic Bacteria

    NASA Astrophysics Data System (ADS)

    Strobel, Herbert J.

    Oxygen is either limiting or absent in many ecosystems. Anaerobic bacteria are often key players in such environments and these organisms have important roles in geo-elemental cycling, agriculture, and medicine. The metabolic versatility of anaerobes is exploited in a variety of industrial processes including fermented food production, biochemical synthesis, and bioremediation. There has been recent considerable interest in developing and enhancing technologies that employ anaerobes as biocatalysts. The study of anaerobic bacteria requires specialized techniques, and specific methods are described for the culture and manipulation of these microbes.

  14. Anaerobic bacteria from hypersaline environments.

    PubMed Central

    Ollivier, B; Caumette, P; Garcia, J L; Mah, R A

    1994-01-01

    Strictly anaerobic halophiles, namely fermentative, sulfate-reducing, homoacetogenic, phototrophic, and methanogenic bacteria are involved in the oxidation of organic carbon in hypersaline environments. To date, six anaerobic fermentative genera, containing nine species, have been described. Two of them are homoacetogens. Six species belong to the family Haloanaerobiaceae, as indicated by their unique 16S rRNA oligonucleotide sequences. Desulfohalobium retbaense and Desulfovibrio halophilus represent the only two moderately halophilic sulfate reducers so far reported. Among anoxygenic phototrophic anaerobes, a few purple bacteria with optimal growth at salinities between 6 and 11% NaCl have been isolated from hypersaline habitats. They belong to the genera Rhodospirillum, Chromatium, Thiocapsa, and Ectothiorhodospira. The commonest organisms isolated so far are Chromatium salexigens, Thiocapsa halophila, and Rhodospirillum salinarum. Extremely halophilic purple bacteria have most commonly been isolated from alkaline brines and require about 20 to 25% NaCl for optimal growth. They belong to the family Ectothiorodhospiraceae. Their osmoregulation involves synthesis or uptake of compatible solutes such as glycine-betaine that accumulate in their cytoplasm. The existence of methanogens in hypersaline environments is related to the presence of noncompetitive substrates such as methylamines, which originate mainly from the breakdown of osmoregulatory amines. Methanogenesis probably does not contribute to the mineralization of carbohydrates at NaCl concentrations higher than 15%. Above this concentration, sulfate reduction is probably the main way to oxidize H2 (although at rates too low to use up all the H2 formed) and occupies a terminal function kn the degradation of carbohydrates. Three genera and five species of halophilic methylotrophic methanogens have been reported. A bloom of phototrophic bacteria in the marine salterns of Salins-de-Giraud, located on the

  15. Factor Analysis of Various Anaerobic Power Tests.

    ERIC Educational Resources Information Center

    Manning, James M.; And Others

    A study investigated the relationship between selected anthropometric variables and of numerous anaerobic power tests with measures obtained on an isokinetic dynamometer. Thirty-one male college students performed several anaerobic power tests, including: the vertical jump using the Lewis formula; the Margaria-Kalamen stair climb test; the Wingate…

  16. Inhibition of anaerobic digestion process: a review.

    PubMed

    Chen, Ye; Cheng, Jay J; Creamer, Kurt S

    2008-07-01

    Anaerobic digestion is an attractive waste treatment practice in which both pollution control and energy recovery can be achieved. Many agricultural and industrial wastes are ideal candidates for anaerobic digestion because they contain high levels of easily biodegradable materials. Problems such as low methane yield and process instability are often encountered in anaerobic digestion, preventing this technique from being widely applied. A wide variety of inhibitory substances are the primary cause of anaerobic digester upset or failure since they are present in substantial concentrations in wastes. Considerable research efforts have been made to identify the mechanism and the controlling factors of inhibition. This review provides a detailed summary of the research conducted on the inhibition of anaerobic processes. The inhibitors commonly present in anaerobic digesters include ammonia, sulfide, light metal ions, heavy metals, and organics. Due to the difference in anaerobic inocula, waste composition, and experimental methods and conditions, literature results on inhibition caused by specific toxicants vary widely. Co-digestion with other waste, adaptation of microorganisms to inhibitory substances, and incorporation of methods to remove or counteract toxicants before anaerobic digestion can significantly improve the waste treatment efficiency. PMID:17399981

  17. Anaerobic Infections in Children with Neurological Impairments.

    ERIC Educational Resources Information Center

    Brook, Itzhak

    1995-01-01

    Children with neurological impairments are prone to develop serious infection with anaerobic bacteria. The most common anaerobic infections are decubitus ulcers; gastrostomy site wound infections; pulmonary infections (aspiration pneumonia, lung abscesses, and tracheitis); and chronic suppurative otitis media. The unique microbiology of each of…

  18. 21 CFR 866.2120 - Anaerobic chamber.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Anaerobic chamber. 866.2120 Section 866.2120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber....

  19. 21 CFR 866.2120 - Anaerobic chamber.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Anaerobic chamber. 866.2120 Section 866.2120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber....

  20. 21 CFR 866.2120 - Anaerobic chamber.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anaerobic chamber. 866.2120 Section 866.2120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber....

  1. 21 CFR 866.2120 - Anaerobic chamber.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Anaerobic chamber. 866.2120 Section 866.2120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber....

  2. 21 CFR 866.2120 - Anaerobic chamber.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Anaerobic chamber. 866.2120 Section 866.2120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber....

  3. Anaerobic acidogenesis of dairy manure

    SciTech Connect

    Krones, M.J.

    1989-01-01

    The objective of this research was to determine if high rate acidogenic fermentation of dairy manure was possible, Whole dairy manure was ground and diluted to 4% total solids and fed to a 10 L anaerobic chemostat operating at 35C and with hydraulic retention times varying between 6 and 50 hours. Several physical and organic parameters of the influent and effluent were measured and compared. The results indicated that the manure was too refractory for high rate liquefaction and hydrolysis. A second experiment was conducted using the same techniques and substrate but varying the substrate pH between 5 and 7. The objectives were to further investigate the pH sensitivity of the acidogenic process and to determine if, by introducing a substrate with a low pH, acidogenesis might proceed more efficiently. The primary result of decreasing the pH was a smaller proportion of methane and an increased proportion of hydrogen in the gas. Liquefaction and hydrolysis continued to be rate limiting and appeared to be a major impediment to two phase anaerobic treatment of dairy manure.

  4. Anaerobic digestion for household organics

    SciTech Connect

    Sinclair, R.; Kelleher, M.

    1995-04-01

    Considerable success in using anaerobic technology for processing household organics is being reported by several recently constructed facilities in Europe. Organic residuals collected separately in a Belgian town are processed to produce biogas and a compost-like material in less than one month. The dry anaerobic conversion process (DRANCO) was developed by Organic Waste Systems (OWS) in the 1980s, with the collaboration of Professor Willy Verstraete at the University of Ghent`s Laboratory of Applied Microbial Ecology. The patented process converts solid and semisolid organic residuals into biogas (for energy recovery) and a stable humus like product. The plant has competing odor sources such as the active landfill and the surrounding farmland - in fact, the smell of livestock manure is quite prevalent in this heavily agricultural area. Addition of the nonrecyclable paper fraction to the feedstock improves the carbon/nitrogen ratio, soaks up moisture, and absorbs odor. The entire Brecht facility does not occupy much space and total material retention time at the site is one month, compared to a number of months for aerobic systems. It also has a low staffing requirement, provides energy self-sufficiency, and the final soil enhancement product meets established quality standards.

  5. Toxicants inhibiting anaerobic digestion: a review.

    PubMed

    Chen, Jian Lin; Ortiz, Raphael; Steele, Terry W J; Stuckey, David C

    2014-12-01

    Anaerobic digestion is increasingly being used to treat wastes from many sources because of its manifold advantages over aerobic treatment, e.g. low sludge production and low energy requirements. However, anaerobic digestion is sensitive to toxicants, and a wide range of compounds can inhibit the process and cause upset or failure. Substantial research has been carried out over the years to identify specific inhibitors/toxicants, and their mechanism of toxicity in anaerobic digestion. In this review we present a detailed and critical summary of research on the inhibition of anaerobic processes by specific organic toxicants (e.g., chlorophenols, halogenated aliphatics and long chain fatty acids), inorganic toxicants (e.g., ammonia, sulfide and heavy metals) and in particular, nanomaterials, focusing on the mechanism of their inhibition/toxicity. A better understanding of the fundamental mechanisms behind inhibition/toxicity will enhance the wider application of anaerobic digestion. PMID:25457225

  6. Spectrum and treatment of anaerobic infections.

    PubMed

    Brook, Itzhak

    2016-01-01

    Anaerobes are the most predominant components of the normal human skin and mucous membranes bacterial flora, and are a frequent cause of endogenous bacterial infections. Anaerobic infections can occur in all body locations: the central nervous system, oral cavity, head and neck, chest, abdomen, pelvis, skin, and soft tissues. Treatment of anaerobic infection is complicated by their slow growth in culture, by their polymicrobial nature and by their growing resistance to antimicrobials. Antimicrobial therapy is frequently the only form of therapy needed, whereas in others it is an important adjunct to drainage and surgery. Because anaerobes generally are isolated mixed with aerobes, the antimicrobial chosen should provide for adequate coverage of both. The most effective antimicrobials against anaerobes are: metronidazole, the carbapenems (imipenem, meropenem, doripenem, ertapenem), chloramphenicol, the combinations of a penicillin and a beta-lactamase inhibitors (ampicillin or ticarcillin plus clavulanate, amoxicillin plus sulbactam, piperacillin plus tazobactam), tigecycline, cefoxitin and clindamycin. PMID:26620376

  7. Anaerobic biorefinery: Current status, challenges, and opportunities.

    PubMed

    Sawatdeenarunat, Chayanon; Nguyen, Duc; Surendra, K C; Shrestha, Shilva; Rajendran, Karthik; Oechsner, Hans; Xie, Li; Khanal, Samir Kumar

    2016-09-01

    Anaerobic digestion (AD) has been in use for many decades. To date, it has been primarily aimed at treating organic wastes, mainly manures and wastewater sludge, and industrial wastewaters. However, with the current advancements, a more open mind is required to look beyond these somewhat restricted original applications of AD. Biorefineries are such concepts, where multiple products including chemicals, fuels, polymers etc. are produced from organic feedstocks. The anaerobic biorefinery concept is now gaining increased attention, utilizing AD as the final disposal step. This review aims at evaluating the potential significance of anaerobic biorefineries, including types of feedstocks, uses for the produced energy, as well as sustainable applications of the generated residual digestate. A comprehensive analysis of various types of anaerobic biorefineries has been developed, including both large-scale and household level applications. Finally, future directives are highlighted showing how anaerobic biorefinery concept could impact the bioeconomy in the near future. PMID:27005786

  8. Effect of music on anaerobic exercise performance.

    PubMed

    Atan, T

    2013-03-01

    For years, mostly the effects of music on cardiorespiratory exercise performance have been studied, but a few studies have examined the effect of music on anaerobic exercise. The purpose of this study was to assess the effect of listening to music and its rhythm on anaerobic exercise: on power output, heart rate and the concentration of blood lactate. 28 male subjects were required to visit the laboratory on 6 occasions, each separated by 48 hours. Firstly, each subject performed the Running-based Anaerobic Sprint Test (RAST) under 3 conditions on separate days: while listening to "slow rhythm music", "fast rhythm music" or "no music". 48 hours after the subjects completed RAST under 3 conditions, Wingate Anaerobic Power (WAN) tests were performed under 3 music conditions. The order of the 3 conditions (slow music, fast music and no music) was selected randomly to prevent an order effect. Results showed no significant differences between 3 conditions in anaerobic power assessments, heart rate or blood lactate (p > 0.05). On the basis of these results it can be said that music cannot improve anaerobic performance. The type of music had no impact on power outputs during RAST and WAN exercise. As a conclusion, listening to music and its rhythm cannot enhance anaerobic performance and cannot change the physiological response to supramaximal exercise. PMID:24744463

  9. EFFECT OF MUSIC ON ANAEROBIC EXERCISE PERFORMANCE

    PubMed Central

    2013-01-01

    For years, mostly the effects of music on cardiorespiratory exercise performance have been studied, but a few studies have examined the effect of music on anaerobic exercise. The purpose of this study was to assess the effect of listening to music and its rhythm on anaerobic exercise: on power output, heart rate and the concentration of blood lactate. 28 male subjects were required to visit the laboratory on 6 occasions, each separated by 48 hours. Firstly, each subject performed the Running-based Anaerobic Sprint Test (RAST) under 3 conditions on separate days: while listening to “slow rhythm music”, “fast rhythm music” or “no music”. 48 hours after the subjects completed RAST under 3 conditions, Wingate Anaerobic Power (WAN) tests were performed under 3 music conditions. The order of the 3 conditions (slow music, fast music and no music) was selected randomly to prevent an order effect. Results showed no significant differences between 3 conditions in anaerobic power assessments, heart rate or blood lactate (p > 0.05). On the basis of these results it can be said that music cannot improve anaerobic performance. The type of music had no impact on power outputs during RAST and WAN exercise. As a conclusion, listening to music and its rhythm cannot enhance anaerobic performance and cannot change the physiological response to supramaximal exercise. PMID:24744463

  10. Anaerobic biodegradation of aromatic compounds.

    PubMed

    Jothimani, P; Kalaichelvan, G; Bhaskaran, A; Selvaseelan, D Augustine; Ramasamy, K

    2003-09-01

    Many aromatic compounds and their monomers are existing in nature. Besides they are introduced into the environment by human activity. The conversion of these aromatic compounds is mainly an aerobic process because of the involvement of molecular oxygen in ring fission and as an electron acceptor. Recent literatures indicated that ring fission of monomers and obligomers mainly occurs in anaerobic environments through anaerobic respiration with nitrate, sulphate, carbon dioxide or carbonate as electron acceptors. These anaerobic processes will help to work out the better situation for bioremediation of contaminated environments. While there are plenty of efforts to reduce the release of these chemicals to the environment, already contaminated sites need to be remediated not only to restore the sites but to prevent the leachates spreading to nearby environment. Basically microorganisms are better candidates for breakdown of these compounds because of their wider catalytic mechanisms and the ability to act even in the absence of oxygen. These microbes can be grouped based on their energy mechanisms. Normally, the aerobic counterparts employ the enzymes like mono-and-dioxygenases. The end product is basically catechol, which further may be metabolised to CO2 by means of quinones reductases cycles. In the absense of reductases compounds, the reduced catechols tend to become oxidised to form many quinone compounds. The quinone products are more recalcitrant and lead to other aesthetic problems like colour in water, unpleasant odour, etc. On the contrary, in the reducing environment this process is prevented and in a cascade of pathways, the cleaved products are converted to acetyl co-A to be integrated into other central metabolite paths. The central metabolite of anaerobic degradation is invariably co-A thio-esters of benzoic acid or hydroxy benzoic acid. The benzene ring undergoes various substitution and addition reactions to form chloro-, nitro-, methyl- compounds

  11. Gram-Positive Anaerobic Cocci

    PubMed Central

    Murdoch, D. A.

    1998-01-01

    Gram-positive anaerobic cocci (GPAC) are a heterogeneous group of organisms defined by their morphological appearance and their inability to grow in the presence of oxygen; most clinical isolates are identified to species in the genus Peptostreptococcus. GPAC are part of the normal flora of all mucocutaneous surfaces and are often isolated from infections such as deep organ abscesses, obstetric and gynecological sepsis, and intraoral infections. They have been little studied for several reasons, which include an inadequate classification, difficulties with laboratory identification, and the mixed nature of the infections from which they are usually isolated. Nucleic acid studies indicate that the classification is in need of radical revision at the genus level. Several species of Peptostreptococcus have recently been described, but others still await formal recognition. Identification has been based on carbohydrate fermentation tests, but most GPAC are asaccharolytic and use the products of protein degradation for their metabolism; the introduction of commercially available preformed enzyme kits affords a physiologically more appropriate method of identification, which is simple and relatively rapid and can be used in routine diagnostic laboratories. Recent reports have documented the isolation in pure culture of several species, notably Peptostreptococcus magnus, from serious infections. Studies of P. magnus have elucidated several virulence factors which correlate with the site of infection, and reveal some similarities to Staphylococcus aureus. P. micros is a strongly proteolytic species; it is increasingly recognized as an important pathogen in intraoral infections, particularly periodontitis, and mixed anaerobic deep-organ abscesses. Comparison of antibiotic susceptibility patterns reveals major differences between species. Penicillins are the antibiotics of choice, although some strains of P. anaerobius show broad-spectrum β-lactam resistance. PMID:9457430

  12. The Pseudomonas aeruginosa Proteome during Anaerobic Growth‡

    PubMed Central

    Wu, Manhong; Guina, Tina; Brittnacher, Mitchell; Nguyen, Hai; Eng, Jimmy; Miller, Samuel I.

    2005-01-01

    Isotope-coded affinity tag analysis and two-dimensional gel electrophoresis followed by tandem mass spectrometry were used to identify Pseudomonas aeruginosa proteins expressed during anaerobic growth. Out of the 617 proteins identified, 158 were changed in abundance during anaerobic growth compared to during aerobic growth, including proteins whose increased expression was expected based on their role in anaerobic metabolism. These results form the basis for future analyses of alterations in bacterial protein content during growth in various environments, including the cystic fibrosis airway. PMID:16291692

  13. Energy from anaerobic methane production. [Sweden

    SciTech Connect

    Not Available

    1982-02-01

    Since 1970 Swedish researchers have been testing the ANAMET (anaerobic-aerobic-methane) process, which involves converting industrial wastewaters via an initial anaerobic microbiological step followed by an aerobic one. Recycling the biomass material in each step allows shorter hydraulic retention times without decreasing stability or solids reduction. Since the first ANAMET plants began operating at a Swedish sugar factory in 1972, 17 more plants have started up or are under construction. Moreover, the ANAMET process has engendered to offshoot BIOMET (biomass-methane) process, a thermophilic anaerobic scheme that can handle sugar-beet pulp as well as grass and other soft, fast-growing biomasses.

  14. Anaerobic microbial transformations in subsurface environments

    SciTech Connect

    Bollag, J.M.; Berry, D.F.; Chanmugathas, P.

    1985-04-01

    The first draft of a literature review article entitled, ''Metabolism of Homocyclic (Benzenoid) and Heterocyclic Aromatic Compounds by Microorganisms Under Anaerobic Conditions'' is completed. The article covers biodegradation of both heterocyclic and homocyclic aromatic compounds under a variety of conditions including nitrate reducing, fermentation, sulfate reducing, and methanogensis. Laboratory experiments have been designed to study the anaerobic biotransformation processes involving organic substance derived from energy residual wastes. The test compounds selected for the initial anaerobic biodegradation experiments include aniline, indole, and pyridine. A Hungate apparatus is presently in operation.

  15. Characterization of anaerobic sulfite reduction by Salmonella typhimurium and purification of the anaerobically induced sulfite reductase

    SciTech Connect

    Hallenbeck, P.C. ); Clark, M.A.; Barrett, E.L. )

    1989-06-01

    Mutants of Salmonella typhimurium that lack the biosynthetic sulfite reductase (cysI and cysJ mutants) retain the ability to reduce sulfite for growth under anaerobic conditions. Here we report studies of sulfite reduction by a cysI mutant of S. typhimurium and purification of the associated anaerobic sulfite reductase. Sulfite reduction for anaerobic growth did not require a reducing atmosphere but was prevented by an argon atmosphere contaminated with air (<0.33%). It was also prevented by the presence of 0.1 mM nitrate. Anaerobic growth in liquid minimal medium, but not on agar, was found to require additions of trace amounts (10{sup {minus}7} M) of cysteine. Spontaneous mutants that grew under the argon contaminated with air also lost the requirement for 10{sup {minus}7}M cysteine for anaerobic growth in liquid. A role for sulfite reduction in anaerobic energy generation was contraindicated by the findings that sulfite reduction did not improve cell yields, and anaerobic sulfite reductase activity was greatest during the stationary phase of growth. Sulfite reductase was purified from the cytoplasmic fraction of the anaerobically grown cysI mutant and was purified 190-fold. The most effective donor in crude extracts was NADH. NADHP and methyl viologen were, respectively, 40 and 30% as effective as NADH. Oxygen reversibly inhibited the enzyme. The anaerobic sulfite reductase showed some resemblance to the biosynthetic sulfite reductase, but apparently it has a unique, as yet unidentified function.

  16. The Energetics of Aerobic versus Anaerobic Respiration.

    ERIC Educational Resources Information Center

    Champion, Timothy D.; Schwenz, Richard W.

    1990-01-01

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

  17. Anaerobic bioprocessing of low rank coals

    SciTech Connect

    Jain, M.K.; Narayan, R.; Han, O.

    1991-01-01

    significant achievements were: (1) Coal decarboxylation was achieved by batch bioreactor systems using adapted anaerobic microbial consortium. (2) Two new isolates with coal decarboxylation potential were obtained from adapted microbial consortia. (3) CHN and TG anaysis of anaerobically biotreated coals have shown an increase in the H/C ratio and evolution rate of volatile carbon which could be a better feedstock for the liquefaction process.

  18. Anaerobic electron acceptor chemotaxis in Shewanella putrefaciens

    NASA Technical Reports Server (NTRS)

    Nealson, K. H.; Moser, D. P.; Saffarini, D. A.

    1995-01-01

    Shewanella putrefaciens MR-1 can grow either aerobically or anaerobically at the expense of many different electron acceptors and is often found in abundance at redox interfaces in nature. Such redox interfaces are often characterized by very strong gradients of electron acceptors resulting from rapid microbial metabolism. The coincidence of S. putrefaciens abundance with environmental gradients prompted an examination of the ability of MR-1 to sense and respond to electron acceptor gradients in the laboratory. In these experiments, taxis to the majority of the electron acceptors that S. putrefaciens utilizes for anaerobic growth was seen. All anaerobic electron acceptor taxis was eliminated by the presence of oxygen, nitrate, nitrite, elemental sulfur, or dimethyl sulfoxide, even though taxis to the latter was very weak and nitrate and nitrite respiration was normal in the presence of dimethyl sulfoxide. Studies with respiratory mutants of MR-1 revealed that several electron acceptors that could not be used for anaerobic growth nevertheless elicited normal anaerobic taxis. Mutant M56, which was unable to respire nitrite, showed normal taxis to nitrite, as well as the inhibition of taxis to other electron acceptors by nitrite. These results indicate that electron acceptor taxis in S. putrefaciens does not conform to the paradigm established for Escherichia coli and several other bacteria. Carbon chemo-taxis was also unusual in this organism: of all carbon compounds tested, the only positive response observed was to formate under anaerobic conditions.

  19. Anaerobic Nitrogen Fixers on Mars

    NASA Astrophysics Data System (ADS)

    Lewis, B. G.

    2000-07-01

    The conversion of atmospheric nitrogen gas to the protein of living systems is an amazing process of nature. The first step in the process is biological nitrogen fixation, the transformation of N2 to NH3. The phenomenon is crucial for feeding the billions of our species on Earth. On Mars, the same process may allow us to discover how life can adapt to a hostile environment, and render it habitable. Hostile environments also exist on Earth. For example, nothing grows in coal refuse piles due to the oxidation of pyrite and marcasite to sulfuric acid. Yet, when the acidity is neutralized, alfalfa and soybean plants develop root nodules typical of symbiotic nitrogen fixation with Rhizobium species possibly living in the pyritic material. When split open, these nodules exhibited the pinkish color of leghemoglobin, a protein in the nodule protecting the active nitrogen-fixing enzyme nitrogenase against the toxic effects of oxygen. Although we have not yet obtained direct evidence of nitrogenase activity in these nodules (reduction of acetylene to ethylene, for example), these findings suggested the possibility that nitrogen fixation was taking place in this hostile, non-soil material. This immediately raises the possibility that freeliving anaerobic bacteria which fix atmospheric nitrogen on Earth, could do the same on Mars.

  20. Anaerobic digestion of cellulosic wastes

    SciTech Connect

    Donaldson, T.L.; Lee, D.D.

    1984-01-01

    Anaerobic digestion is a potentially attractive technology for volume reduction of cellulosic wastes. A substantial fraction of the waste is converted to off-gas and a relatively small volume of biologically stabilized sludge is produced. Process development work is underway using a 75-L digester to verify rates and conversions obtained at the bench scale, to develop start-up and operating procedures, and to generate effluent for characterization and disposal studies. Three runs using batch and batch-fed conditions have been made lasting 36, 90, and over 200 days. Solids solubilization and gas production rates and total solids destruction have met or exceeded the target values of 0.6 g cellulose per L of reactor per day, 0.5 L off-gas per L of reactor per day, and 80% destruction of solids, respectively. Successful start-up procedures have been developed, and preliminary effluent characterization and disposal studies have been done. A simple dynamic process model has been constructed to aid in further process development and for use in process monitoring and control of a large-scale digester. 7 references, 5 figures, 1 table.

  1. Anaerobic digestion of cellulosic wastes

    SciTech Connect

    Lee, D.D.; Donaldson, T.L.

    1985-01-01

    Anaerobic digestion is a potentially attractive technology for volume reduction of low-level radioactive cellulosic wastes. A substantial fraction of the waste is converted to off-gas and a relatively small volume of biologically stabilized sludge is produced. Process development work has been completed using a 75-L digester to verify rates and conversions obtained at the bench scale. Start-up and operating procedures have been developed, and effluent was generated for characterization and disposal studies. Three runs using batch and fed-batch conditions were made lasting 36, 90, and 423 d. Solids solubilization rates and gas production rates averaged approximately 1.8 g cellulose per L of reactor per d and 1.2 L of off-gas per L reactor per d. Greater than 80% destruction of the volatile suspended solids was obtained. A simple dynamic process model was constructed to aid in process design and for use in process monitoring and control of a large-scale digester.

  2. Improvement of anaerobic soil disinfestation.

    PubMed

    Runia, W T; Molendirk, L P G; Ludeking, D J W; Schomaker, C H

    2012-01-01

    With increasing worldwide restrictions for soil fumigants, growers loose an important tool to control soilborne pests and pathogens. Environmentally friendly alternatives are urgently needed and anaerobic soil disinfestation (ASD) may be one of them. Traditional ASD with fresh grass is already applied in open field vegetables but the mode of action is unknown. Therefore, trials were performed under controlled conditions using soil-filled buckets, in which several processed defined organic materials were incorporated and compared with fresh grass. The effect of inundation was also studied. Target organisms were Pratylenchus penetrans, Meloidogyne hapla, Globodera pallida and Verticillium dahliae. Results showed that grass (traditional ASD) was less effective than the organic materials. All materials proved to be effective at 16 degrees C against all target organisms. However, exposure time, dosages, soil type and the temperature at which the experiments were performed influenced the effectiveness. P. penetrans was eliminated most easily whereas V. dahliae was most difficult to control. Efficacy was higher in sandy soil than in light marine clay. Inundation at 16 degrees C proved to be effective against P. penetrans and G. pallida in both soil types at sufficient exposure times. A soil temperature of 8 degrees C was sometimes too low for efficacy. Gas production of CO2, NH3, H2S, CH4 and N2O and gas consumption of O2 and production of fatty acids during ASD proved to depend on type of organic materials, soil type, temperature, dosage and exposure time. This first step in unravelling the mode of action has already shown several critical parameters for efficacy. Additional knowledge about the complete mechanisms of action may lead to a more reliable, effective and quicker soil disinfestation. PMID:23885444

  3. Anaerobic biotransformation of chlorinated alkenes

    SciTech Connect

    Zhuang, P.

    1994-01-01

    Chlorinated alkenes are widely found in contaminated subsurface soil and groundwater. The highly chlorinated alkene (i.e., PCE) is not subject to aerobic biotransformation. The aim of this research was to explore the potential of using anaerobic processes (i.e., denitrification, sulfate-reduction and methanogenesis) for chlorinated alkenes biotransformation. Contaminated soil samples were used throughout this study. Soil microcosms simulating field anoxic conditions with various nutrients amendment, liquid microcosms as well as enrichment liquid cultures were developed to delineate the dechlorination process. The effect of biomass, chlorinated alkenes concentration and site specific conditions (e.g., temperature and pH) on the dechlorination and the primary metabolic process was investigated. The role of sorption and nutritional needs (i.e., electron donor) were also studied. A preliminary study revealed that denitrification was the least affected by low temperatures as compared to sulfate-reduction and methanogenesis. Although dechlorination took place under sequential denitrifying and methanogenic conditions and under sulfate-reducing conditions, further studies concluded that fermentative and methanogenic bacteria were responsible for the observed dechlorination. In most cases, dechlorination of PCE or TCE resulted in the accumulation of cDCE. However, a VC-producing culture was developed from the PCE-contaminated soil. In general, the dechlorination process could be enhanced by increasing electron donor and biomass concentration. At relatively low concentrations, the dechlorination rate was also increased with increasing chlorinated alkene concentration. Dechlorination even proceeded at high chlorinated alkene concentrations when methane production was inhibited. However, as the concentration of the chlorinated alkenes increased, severe toxicity eventually halted the dechlorination process.

  4. ANAEROBIC BIOLOGICAL TREATMENT OF PRODUCED WATER

    SciTech Connect

    John R. Gallagher

    2001-07-31

    During the production of oil and gas, large amounts of water are brought to the surface and must be disposed of in an environmentally sensitive manner. This is an especially difficult problem in offshore production facilities where space is a major constraint. The chief regulatory criterion for produced water is oil and grease. Most facilities have little trouble meeting this criterion using conventional oil-water separation technologies. However, some operations have significant amounts of naphthenic acids in the water that behave as oil and grease but are not well removed by conventional technologies. Aerobic biological treatment of naphthenic acids in simulated-produced water has been demonstrated by others; however, the system was easily overloaded by the large amounts of low-molecular-weight organic acids often found in produced waters. The objective of this research was to determine the ability of an anaerobic biological system to treat these organic acids in a simulated produced water and to examine the potential for biodegradation of the naphthenic acids in the anaerobic environment. A small fixed-film anaerobic biological reactor was constructed and adapted to treat a simulated produced water. The bioreactor was tubular, with a low-density porous glass packing material. The inocula to the reactor was sediment from a produced-water holding pond from a municipal anaerobic digester and two salt-loving methanogenic bacteria. During start-up, the feed to the reactor contained glucose as well as typical produced-water components. When glucose was used, rapid gas production was observed. However, when glucose was eliminated and the major organic component was acetate, little gas was generated. Methane production from acetate may have been inhibited by the high salt concentrations, by sulfide, or because of the lack, despite seeding, of microbes capable of converting acetate to methane. Toluene, a minor component of the produced water (0.1 g/L) was removed in the

  5. Animal model for anaerobic lung abscess.

    PubMed Central

    Kannangara, D W; Thadepalli, H; Bach, V T; Webb, D

    1981-01-01

    There are no satisfactory animal models for the study of anaerobic lung abscess. Aspiration of food, gastric mucin, or hydrochloric acid, or any combination of these, along with oropharyngeal bacteria, is commonly believed to cause aspiration pneumonia and lung abscess. In the animal model described, none of the adjuvants was effective in producing anaerobic lung abscesses. Anaerobic bacteria derived from dental scrapings of a healthy adult (Peptococcus morbillorum, Fusobacterium nucleatum, Eubacterium lentum, and Bacteroides fragilis), when inoculated transtracheally without any adjuvants into New Zealand male white rabbits, consistently produced lung abscesses. Neither B fragilis by itself nor a mixture of P. morbillorum, F. nucleatum, and E. lentum without the addition of B. fragilis produced lung abscesses. The bacterial isolates used in this study were stored in prereduced chopped-meat-glucose medium and subcultured several times and were found effective in reproducing anaerobic lung abscesses repeatedly. This animal model is suitable for the study of pathogenesis, diagnosis, and treatment of B. fragilis-associated anaerobic lung abscess. Images PMID:7216463

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

    PubMed

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

    1998-01-01

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

  7. Anaerobes: a new aetiology in cavitary pneumoconiosis.

    PubMed Central

    del Campo, J M; Hitado, J; Gea, G; Colmeiro, A; Lanza, A M; Muñoz, J A; Mosquera, J A

    1982-01-01

    The role of mycobacteria in the cavitation of large pneumoconiotic masses is well established. In other cases softness is attributed to an ischaemic or aseptic necrosis. Five cases are described in which cavitation of the pulmonary masses was caused by anaerobic bacteria, confirmed by the growth of such bacterial in cultures after transtracheal or transpleural puncture. Repeated cultures for mycobacteria gave negative results. Two cases were acute, having serious complications such as bronchopleural fistula, empyema, and serious respiratory insufficiency. The role of anaerobes in cavitary pneumoconiosis has not been recognised previously, probably because of the special conditions required to culture these bacteria and the infrequent use of transtracheal puncture in the diagnosis of this entity. The prevalence of anaerobes as agents capable of cavitating pneumoconiotic masses remains to be established. Images PMID:6128024

  8. Biochar from anaerobically digested sugarcane bagasse.

    PubMed

    Inyang, Mandu; Gao, Bin; Pullammanappallil, Pratap; Ding, Wenchuan; Zimmerman, Andrew R

    2010-11-01

    This study was designed to investigate the effect of anaerobic digestion on biochar produced from sugarcane bagasse. Sugarcane bagasse was anaerobically digested to produce methane. The digested residue and fresh bagasse was pyrolyzed separately into biochar at 600 degrees C in nitrogen environment. The digested bagasse biochar (DBC) and undigested bagasse biochar (BC) were characterized to determine their physicochemical properties. Although biochar was produced from the digested residue (18% by weight) and the raw bagasse (23%) at a similar rate, there were many physiochemical differences between them. Compared to BC, DBC had higher pH, surface area, cation exchange capacity (CEC), anion exchange capacity (AEC), hydrophobicity and more negative surface charge, all properties that are generally desirable for soil amelioration, contaminant remediation or wastewater treatment. Thus, these results suggest that the pyrolysis of anaerobic digestion residues to produce biochar may be an economically and environmentally beneficial use of agricultural wastes. PMID:20634061

  9. Biochemistry and physiology of anaerobic bacteria

    SciTech Connect

    2000-05-18

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

  10. ANAEROBIC AND AEROBIC TREATMENT OF CHLORINATED ALIPHATIC COMPOUNDS

    EPA Science Inventory

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

  11. Thermophilic anaerobic digestion of high strength wastewaters

    SciTech Connect

    Wiegant, W.M.; Claassen, J.A.; Lettinga, G.

    1985-09-01

    Investigations on the thermophilic anaerobic treatment of high-strength wastewaters (14-65 kg COD/mT) are presented. Vinasse, the wastewater of alcohol distilleries, was used as an example of such wastewaters. Semicontinuously fed digestion experiments at high retention times revealed that the effluent quality of digestion at 55C is comparable with that at 30C at similar loading rates. The amount of methane formed per kilogram of vinasse drops almost linearly with increasing vinasse concentrations. The treatment of vinasse was also investigated using upflow anaerobic sludge blanket (UASB) reactors.

  12. Computer-assisted identification of anaerobic bacteria.

    PubMed Central

    Kelley, R W; Kellogg, S T

    1978-01-01

    A computer program was developed to identify anaerobic bacteria by using simultaneous pattern recognition via a Bayesian probabilistic model. The system is intended for use as a rapid, precise, and reproducible aid in the identification of unknown isolates. The program operates on a data base of 28 genera comprising 238 species of anaerobic bacteria that can be separated by the program. Input to the program consists of biochemical and gas chromatographic test results in binary format. The system is flexible and yields outputs of: (i) most probable species, (ii) significant test results conflicting with established data, and (iii) differential tests of significance for missing test results. PMID:345970

  13. Optimizing anaerobic soil disinfestation: an alternative to soil fumigation?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil disinfestation methods using anaerobic decomposition of organic matter were developed in the Netherlands and Japan as an ecological alternative to MeBr. Anaerobic soil disinfestation (ASD) works by creating a combination of anaerobic soil conditions and readily available carbon pools to stimula...

  14. Anaerobic Digestion. Student Manual. Biological Treatment Process Control.

    ERIC Educational Resources Information Center

    Carnegie, John W., Ed.

    This student manual contains the textual material for a four-lesson unit on anaerobic digestion control. Areas addressed include: (1) anaerobic sludge digestion (considering the nature of raw sludge, purposes of anaerobic digestion, the results of digestion, types of equipment, and other topics); (2) digester process control (considering feeding…

  15. The Influence of Hydration on Anaerobic Performance: A Review

    ERIC Educational Resources Information Center

    Kraft, Justin A.; Green, James M.; Bishop, Phillip A.; Richardson, Mark T.; Neggers, Yasmin H.; Leeper, James D.

    2012-01-01

    This review examines the influence of dehydration on muscular strength and endurance and on single and repeated anaerobic sprint bouts. Describing hydration effects on anaerobic performance is difficult because various exercise modes are dominated by anaerobic energy pathways, but still contain inherent physiological differences. The critical…

  16. Environmental impacts of anaerobic digestion and the use of anaerobic residues as soil amendment

    SciTech Connect

    Mosey, F.E.

    1996-01-01

    This paper defines the environmental role of anaerobic digestion within the overall objective of recovering energy from renewable biomass resources. Examples and opportunities for incorporating anaerobic digestion into biomass-to-energy schemes are discussed, together with environmental aspects of anaerobic digestion plants. These include visual, public amenity, pathogens and public health, odor control, and gaseous emissions. Digestate disposal and the benefits of restrictions on recycling organic wastes and biomass residues back to the land are discussed, particularly as they relate to American and European codes of practice and environmental legislation. The paper concludes that anaerobic digestion, if performed in purpose-designed reactors that efficiently recover and use biogas, is an environmentally benign process that can enhance energy recovery and aid the beneficial land use of plant residues in many biomass-to-energy schemes.

  17. Environmental impacts of anaerobic digestion and the use of anaerobic residues as soil amendment

    SciTech Connect

    Mosey, F.E.

    1995-11-01

    This paper defines the environmental role of anaerobic digestion with the overall objective of recovering energy from renewable biomass resources. Examples and opportunities for incorporating anaerobic digestion into biomass-to-energy schemes are discussed, together with environmental aspects of anaerobic digestion plants. These include visual, public amenity, pathogens and public health, odor control, and gaseous emissions. Digestate disposal and the benefits of restrictions on recycling organic wastes and biomass residues back to the land are discussed, particularly as they relate to American and European codes of practice and environmental legislation. The paper concludes that anaerobic digestion, if performed in purpose-designed reactors that efficiently recover and use biogas, if performed in purpose-designed reactors that efficiently recover and use biogas, is an environmentally benign process that can enhance energy recovery and aid the beneficial land use of plant residues in many biomass-to-energy schemes.

  18. Studies on upflow anaerobic filter

    NASA Astrophysics Data System (ADS)

    Varandani, Nanik Sobhraj

    The thesis presents a critical review of the available literature on the various studies carried out on various aspects of Upflow Anaerobic Filter (UAF) throughout the world. Young and McCarty (1969) did the pioneering work in developing UAF in 1969, since then several studies have been carried out by different researchers using different substrates under different operating conditions and variety of supporting media. However, the most significant modification of the original reactor developed by Young and McCarty (1968), has been the development and use of high porosity media. The use of high porosity media, in fact, has changed the character of the reactor, from basically a fixed film reactor to a fixed film reactor in which the contribution by the suspended bio-solids, entrapped in the numerous media pores, in the substrate removal is quite significant that is to say that the reactor no longer remains a biological reactor which can be modeled and designed on the basis of biofilm kinetics only. The thesis presents an attempt to validate the developed mathematical model(s) by using the laboratory scale reactor performance data and the calculated values of reaction kinetic and bio-kinetic constants. To simplify the verification process, computer programmes have been prepared using the "EXCELL" software and C language. The results of the "EXCELL" computer program runs are tabulated at table no. 7.1 to 7.5. The verification of various mathematical models indicate that the model III B, i.e. Non ideal plug flow model assumed to consist of Complete Mix Reactors in series based on reaction kinetics, gives results with least deviation from the real situation. An interesting observation being that the model offers least deviation or nearly satisfies the real situation for a particular COD removal efficiency, for a particular OLR, eg. the least deviations are obtained at COD removal efficiency of 89% for OLR 2, 81.5% for OLR 4, 78.5% for OLR 6 . However, the use of the

  19. Analysis of denitrification in swine anaerobic lagoons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic lagoons are a common management practice for the treatment of swine wastewater. Although these lagoons were once thought to be relatively simple; their physical, chemical, and biological processes are actually very sophisticated. To get a better understanding of the processes which occur i...

  20. Enrichment of denitrifying anaerobic methane oxidizing microorganisms.

    PubMed

    Hu, Shihu; Zeng, Raymond J; Burow, Luke C; Lant, Paul; Keller, Jurg; Yuan, Zhiguo

    2009-10-01

    The microorganisms responsible for anaerobic oxidation of methane (AOM) coupled to denitrification have not been clearly elucidated. Three recent publications suggested it can be achieved by a denitrifying bacterium with or without the involvement of anaerobic methanotrophic archaea. A key factor limiting the progress in this research field is the shortage of enrichment cultures performing denitrifying anaerobic methane oxidation (DAMO). In this study, DAMO cultures were enriched from mixed inoculum including sediment from a freshwater lake, anaerobic digester sludge and return activated sludge from a sewage treatment plant. Two reactors, operated at 35°C and at 22°C, respectively, showed simultaneous methane oxidation and nitrate reduction after several months of operation. Analysis of 16S rRNA gene clone libraries from the 35°C enrichment showed the presence of an archaeon closely related to other DAMO archaea and a dominated bacterium belonging to the yet uncultivated NC10 phylum. This culture preferred nitrite to nitrate as the electron acceptor. The present study suggests that the archaea are rather methanotrophs than methanogens. The highest denitrification rate achieved was 2.35 mmol NO3 (-) -N gVSS(-1)  day(-1) . The culture enriched at 22°C contained the same NC10 bacterium observed in the culture enriched at 35°C but no archaea. PMID:23765890

  1. Anaerobic Toxicity of Cationic Silver Nanoparticles

    EPA Science Inventory

    The microbial toxicity of silver nanoparticles (AgNPs) stabilized with different capping agents was compared to that of Ag+ under anaerobic conditions. Three AgNPs were investigated: (1) negatively charged citrate-coated AgNPs (citrate-AgNPs), (2) minimally charged p...

  2. Anaerobic digestion of space mission wastes.

    PubMed

    Chynoweth, D P; Owens, J M; Teixeira, A A; Pullammanappallil, P; Luniya, S S

    2006-01-01

    The technical feasibility of applying leachbed high-solids anaerobic digestion for reduction and stabilization of the organic fraction of solid wastes generated during space missions was investigated. This process has the advantages of not requiring oxygen or high temperature and pressure while producing methane, carbon dioxide, nutrients, and compost as valuable products. Anaerobic biochemical methane potential assays run on several waste feedstocks expected during space missions resulted in ultimate methane yields ranging from 0.23 to 0.30 L g-1 VS added. Modifications for operation of a leachbed anaerobic digestion process in space environments were incorporated into a new design, which included; (1) flooded operation to force leachate through densified feedstock beds; and (2) separation of biogas from leachate in a gas collection reservoir. This mode of operation resulted in stable performance with 85% conversion of a typical space solid waste blend, and a methane yield of 0.3 Lg per g VS added after a retention time of 15 days. These results were reproduced in a full-scale prototype system. A detailed analysis of this process was conducted to design the system sized for a space mission with a six-person crew. Anaerobic digestion compared favorably with other technologies for solid waste stabilization. PMID:16784202

  3. Biodegradability of leathers through anaerobic pathway.

    PubMed

    Dhayalan, K; Fathima, N Nishad; Gnanamani, A; Rao, J Raghava; Nair, B Unni; Ramasami, T

    2007-01-01

    Leather processing generates huge amounts of both solid and liquid wastes. The management of solid wastes, especially tanned leather waste, is a challenging problem faced by tanners. Hence, studies on biodegradability of leather become imperative. In this present work, biodegradability of untanned, chrome tanned and vegetable tanned leather under anaerobic conditions has been addressed. Two different sources of anaerobes have been used for this purpose. The effect of detanning as a pretreatment method before subjecting the leather to biodegradation has also been studied. It has been found that vegetable tanned leather leads to more gas production than chrome tanned leather. Mixed anaerobic isolates when employed as an inoculum are able to degrade the soluble organics of vegetable tanned material and thus exhibit an increased level of gas production during the initial days, compared to the results of the treatments that received the anaerobic sludge. With chrome tanned materials, there was not much change in the volume of the gas produced from the two different sources. It has been found that detanning tends to improve the biodegradability of both types of leathers. PMID:16740383

  4. Process configuration role in anaerobic biotransformations

    SciTech Connect

    Speece, R.E.

    1998-07-01

    Defining the environmental conditions which would enable anaerobic processes to consistently produce effluents containing only non-detectable concentrations of degradable organics would remove one of the main drawbacks to wider application of this important treatment technology. Recently specific metabolic intermediates formed in the anaerobic biotransformation of complex organics have been found to enhance or curtail process performance. Using acrylate and acrolein as representative hazardous chemicals, modifications in staging and reactor operation procedures have been observed in the author's laboratory to profoundly impact the rate and completeness of the biotransformation process. Specific metabolic intermediates formed in the biotransformation of complex substrates to a large extent will control a given process performance and process configuration greatly impacts the metabolic pathway, thus impacting the intermediates formed as well. There is a growing body of literature to indicate that process performance in anaerobic biotransformation is greatly impacted by reactor configuration. There is also some evidence that metabolic precursors impact the subsequent efficiency of conversion of volatile fatty acids (VFA) ultimately to CH{sub 4}. But although profound differences in the performance of anaerobic biotransformation are reported for various process configurations, there are no published criteria to guide the rational design of stages/phased processes. Clarification of the relative merits of single stage, two stage, two phase, granules and biofilms as well as CSTR and plug flow modes in the biotransformation of hazardous pollutants would be foundational for future research and development.

  5. ANAEROBIC BIODEGRADABILITY OF NON-PETROLEUM OILS.

    EPA Science Inventory

    Research has demonstrated that vegetable oils are amenable to anaerobic biodegradation. This is in contrast to petroleum oils. Vegetable oils are already oxygenated because they are composed of fatty acids and glycerols, which contribute to the biodegradability. A strategy has be...

  6. Anaerobic xylose fermentation by Spathaspora passalidarum.

    PubMed

    Hou, X

    2012-04-01

    A cost-effective conversion of lignocellulosic biomass into bioethanol requires that the xylose released from the hemicellulose fraction (20-40% of biomass) can be fermented. Baker's yeast, Saccharomyces cerevisiae, efficiently ferments glucose but it lacks the ability to ferment xylose. Xylose-fermenting yeast such as Pichia stipitis requires accurately controlled microaerophilic conditions during the xylose fermentation, rendering the process technically difficult and expensive. In this study, it is demonstrated that under anaerobic conditions Spathaspora passalidarum showed high ethanol production yield, fast cell growth, and rapid sugar consumption with xylose being consumed after glucose depletion, while P. stipitis was almost unable to utilize xylose under these conditions. It is further demonstrated that for S. passalidarum, the xylose conversion takes place by means of NADH-preferred xylose reductase (XR) and NAD(+)-dependent xylitol dehydrogenase (XDH). Thus, the capacity of S. passalidarum to utilize xylose under anaerobic conditions is possibly due to the balance between the cofactor's supply and demand through this XR-XDH pathway. Only few XRs with NADH preference have been reported so far. 2-Deoxy glucose completely inhibited the conversion of xylose by S. passalidarum under anaerobic conditions, but only partially did that under aerobic conditions. Thus, xylose uptake by S. passalidarum may be carried out by different xylose transport systems under anaerobic and aerobic conditions. The presence of glucose also repressed the enzymatic activity of XR and XDH from S. passalidarum as well as the activities of those enzymes from P. stipitis. PMID:22124720

  7. Hemicellulases from anaerobic thermophiles. Progress report

    SciTech Connect

    Wiegel, J.

    1994-05-01

    The longterm goal of this research effort is to obtain an anaerobic thermophilic bacterium that efficiently converts various hemicellulose-containing biomass to ethanol over a broad pH range. The strategy is to modify the outfit and regulation of the rate-limiting xylanases, glycosidases and xylan esterases in the ethanologenic, anaerobic thermophile Thermoanaerobacter ethanolicus, which grows between pH 4.5 and 9.5. Although it utilizes xylans, the xylanase, acetyl(xylan) esterase and O-methylglucuronidase activities in T. ethanolicus are barely measurable and regarded as the rate limiting steps in its xylan utilization. Thus, and also due to the presently limited knowledge of hemicellulases in anaerobic thermophiles, we characterize the hemicellulolytic enzymes from this and other anaerobic thermophiles as enzyme donors. Beside the active xylosidase/arabinosidase from T. ethanolicus, exhibiting the two different activities, we characterized 2 xylosidases, two acetyl(xylan) esterases, and an O-methylglucuronidase from Thermoanaerobacterium spec. We will continue with the characterization of xylanases from novel isolated slightly acidophilic, neutrophilic and slightly alkalophilic thermophiles. We have cloned, subcloned and partially sequenced the 165,000 Da (2 x 85,000) xylosidase/arabinosidase from T. ethanolicus and started with the cloning of the esterases from Thermoanaerobacterium spec. Consequently, we will develop a shuttle vector and continue to apply electroporation of autoplasts as a method for cloning into T. ethanolicus.

  8. Anaerobic degradation of linear alkylbenzene sulfonate.

    PubMed

    Mogensen, Anders S; Haagensen, Frank; Ahring, Birgitte K

    2003-04-01

    Linear alkylbenzene sulfonate (LAS) found in wastewater is removed in the wastewater treatment facilities by sorption and aerobic biodegradation. The anaerobic digestion of sewage sludge has not been shown to contribute to the removal. The concentration of LAS based on dry matter typically increases during anaerobic stabilization due to transformation of easily degradable organic matter. Hence, LAS is regarded as resistant to biodegradation under anaerobic conditions. We present data from a lab-scale semi-continuously stirred tank reactor (CSTR) spiked with linear dodecylbenzene sulfonate (C12 LAS), which show that C12 LAS was biodegradable under methanogenic conditions. Sorption of C12 LAS on sewage sludge was described with a Freundlich isotherm. The C12 LAS sorption was determined with different concentrations of total solids (TS). In the semi-continuously stirred tank reactor, 18% of the added C12 LAS was bioavailable and 20% was biotransformed when spiking with 100 mg/L of C12 LAS and a TS concentration of 14.2 mg/L. Enhanced bioavailability of C12 LAS was obtained in an upflow anaerobic sludge blanket (UASB) reactor inoculated with granular sludge and sewage sludge. Biodegradation under thermophilic conditions was 37% with LAS as sole carbon source. Benzaldehyde was produced in the UASB reactor during LAS transformation. PMID:12685701

  9. Anaerobic Digestion in a Flooded Densified Leachbed

    NASA Technical Reports Server (NTRS)

    Chynoweth, David P.; Teixeira, Arthur A.; Owens, John M.; Haley, Patrick J.

    2009-01-01

    A document discusses the adaptation of a patented biomass-digesting process, denoted sequential batch anaerobic composting (SEBAC), to recycling of wastes aboard a spacecraft. In SEBAC, high-solids-content biomass wastes are converted into methane, carbon dioxide, and compost.

  10. Early Microbial Evolution: The Age of Anaerobes.

    PubMed

    Martin, William F; Sousa, Filipa L

    2016-02-01

    In this article, the term "early microbial evolution" refers to the phase of biological history from the emergence of life to the diversification of the first microbial lineages. In the modern era (since we knew about archaea), three debates have emerged on the subject that deserve discussion: (1) thermophilic origins versus mesophilic origins, (2) autotrophic origins versus heterotrophic origins, and (3) how do eukaryotes figure into early evolution. Here, we revisit those debates from the standpoint of newer data. We also consider the perhaps more pressing issue that molecular phylogenies need to recover anaerobic lineages at the base of prokaryotic trees, because O2 is a product of biological evolution; hence, the first microbes had to be anaerobes. If molecular phylogenies do not recover anaerobes basal, something is wrong. Among the anaerobes, hydrogen-dependent autotrophs--acetogens and methanogens--look like good candidates for the ancestral state of physiology in the bacteria and archaea, respectively. New trees tend to indicate that eukaryote cytosolic ribosomes branch within their archaeal homologs, not as sisters to them and, furthermore tend to root archaea within the methanogens. These are major changes in the tree of life, and open up new avenues of thought. Geochemical methane synthesis occurs as a spontaneous, abiotic exergonic reaction at hydrothermal vents. The overall similarity between that reaction and biological methanogenesis fits well with the concept of a methanogenic root for archaea and an autotrophic origin of microbial physiology. PMID:26684184

  11. Cellulose biosynthesis by the beta-proteobacterium, Chromobacterium violaceum.

    PubMed

    Recouvreux, Derce O S; Carminatti, Claudimir A; Pitlovanciv, Ana K; Rambo, Carlos R; Porto, Luismar M; Antônio, Regina V

    2008-11-01

    The Chromobacterium violaceum ATCC 12472 genome was sequenced by The Brazilian National Genome Project Consortium. Previous annotation reported the presence of cellulose biosynthesis genes in that genome. Analysis of these genes showed that, as observed in other bacteria, they are organized in two operons. In the present work, experimental evidences of the presence of cellulose in the extracellular matrix of the biofilm produced by C. violaceum in static cultures are shown. Biofilm samples were enzymatically digested by cellulase, releasing glucose units, suggesting the presence of cellulose as an extracellular matrix component. Fluorescence microscopy observations showed that C. violaceum produces a cellulase-sensitive extracellular matrix composed of fibers able to bind calcofluor. C. violaceum grows on medium containing Congo red, forming brown-red colonies. Together, these results suggest that cellulase-susceptible matrix material is cellulose. Scanning electronic microscopy analysis showed that the extracellular matrix exhibited a network of microfibrils, typical of bacterial cellulose. Although cellulose production is widely distributed between several bacterial species, including at least the groups of Gram-negative proteobacteria alpha and gamma, we give for the first time experimental evidence for cellulose production in beta-proteobacteria. PMID:18820969

  12. Recovery of anaerobic, facultative, and aerobic bacteria from clinical specimens in three anaerobic transport systems.

    PubMed Central

    Helstad, A G; Kimball, J L; Maki, D G

    1977-01-01

    With aspirated specimens from clinical infections, we evaluated the recovery of anaerobic, aerobic, and facultative bacteria in three widely used transport systems: (i) aspirated fluid in a gassed-out tube (FGT), (ii) swab in modified Cary and Blair transport medium (SCB), and (iii) swab in a gassed-out tube (SGT). Transport tubes were held at 25 degrees C and semiquantitatively sampled at 0, 2, 24, and 48 h. Twenty-five clinical specimens yielded 75 anaerobic strains and 43 isolates of facultative and 3 of aerobic bacteria. Only one anaerobic isolate was not recovered in the first 24 h, and then, only in the SGT. At 48 h, 73 anaerobic strains (97%) were recovered in the FGT, 69 (92%) in the SCB, and 64 (85%) in the SGT. Two problems hindered the recovery of anaerobes in the SCB and SGT systems: first die-off of organisms, as evidenced by a decrease in colony-forming units of 20 strains (27%) in the SCB and 25 strains (33%) in the SGT, as compared with 7 strains (9%) in the FGT, over 48 h; and second, overgrowth of facultative bacteria, more frequent with SCB and SGT. The FGT method was clearly superior at 48 h to the SCB and SGT systems in this study and is recommended as the preferred method for transporting specimens for anaerobic culture. PMID:328525

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

    Agrawal, Akhil; Gieg, Lisa M.

    2013-01-01

    Alkanes comprise a substantial fraction of crude oil and refined fuels. As such, they are prevalent within deep subsurface fossil fuel deposits and in shallow subsurface environments such as aquifers that are contaminated with hydrocarbons. These environments are typically anaerobic, and host diverse microbial communities that can potentially use alkanes as substrates. Anaerobic alkane biodegradation has been reported to occur under nitrate-reducing, sulfate-reducing, and methanogenic conditions. Elucidating the pathways of anaerobic alkane metabolism has been of interest in order to understand how microbes can be used to remediate contaminated sites. Alkane activation primarily occurs by addition to fumarate, yielding alkylsuccinates, unique anaerobic metabolites that can be used to indicate in situ anaerobic alkane metabolism. These metabolites have been detected in hydrocarbon-contaminated shallow aquifers, offering strong evidence for intrinsic anaerobic bioremediation. Recently, studies have also revealed that alkylsuccinates are present in oil and coal seam production waters, indicating that anaerobic microbial communities can utilize alkanes in these deeper subsurface environments. In many crude oil reservoirs, the in situ anaerobic metabolism of hydrocarbons such as alkanes may be contributing to modern-day detrimental effects such as oilfield souring, or may lead to more beneficial technologies such as enhanced energy recovery from mature oilfields. In this review, we briefly describe the key metabolic pathways for anaerobic alkane (including n-alkanes, isoalkanes, and cyclic alkanes) metabolism and highlight several field reports wherein alkylsuccinates have provided evidence for anaerobic in situ alkane metabolism in shallow and deep subsurface environments. PMID:23761789

  15. FCPP application to utilize anaerobic digester gas

    SciTech Connect

    Nakayama, Yoshio; Kusama, Nobuyuki; Wada, Katsuya

    1996-12-31

    Toshiba and a municipal organization of Yokohama city are jointly conducting a program to utilize ADG (Anaerobic Digester Gas) more effectively. ADG which contains about 60% methane is produced by anaerobic digestion of waste water treatment sludge and has been used as an energy source for heating digestion tanks in sewage treatment plants and/or for combustion engine fuel. This program is focused on operating a commercial Phosphoric Acid Fuel Cell (PAFC) power plant on ADG because of its inherently high fuel efficiency and low emissions characteristics. According to the following joint program, we have successfully demonstrated an ADG fueled FCPP The success of this study promises that the ADG fueled FCPP, an environment-friendly power generation system, will be added to the line-up of PC25{trademark}C applications.

  16. Note: Small anaerobic chamber for optical spectroscopy.

    PubMed

    Chauvet, Adrien A P; Agarwal, Rachna; Cramer, William A; Chergui, Majed

    2015-10-01

    The study of oxygen-sensitive biological samples requires an effective control of the atmosphere in which they are housed. In this aim however, no commercial anaerobic chamber is adequate to solely enclose the sample and small enough to fit in a compact spectroscopic system with which analysis can be performed. Furthermore, spectroscopic analysis requires the probe beam to pass through the whole chamber, introducing a requirement for adequate windows. In response to these challenges, we present a 1 l anaerobic chamber that is suitable for broad-band spectroscopic analysis. This chamber has the advantage of (1) providing access, via a septum, to the sample and (2) allows the sample position to be adjusted while keeping the chamber fixed and hermetic during the experiment. PMID:26520998

  17. Note: Small anaerobic chamber for optical spectroscopy

    NASA Astrophysics Data System (ADS)

    Chauvet, Adrien A. P.; Agarwal, Rachna; Cramer, William A.; Chergui, Majed

    2015-10-01

    The study of oxygen-sensitive biological samples requires an effective control of the atmosphere in which they are housed. In this aim however, no commercial anaerobic chamber is adequate to solely enclose the sample and small enough to fit in a compact spectroscopic system with which analysis can be performed. Furthermore, spectroscopic analysis requires the probe beam to pass through the whole chamber, introducing a requirement for adequate windows. In response to these challenges, we present a 1 l anaerobic chamber that is suitable for broad-band spectroscopic analysis. This chamber has the advantage of (1) providing access, via a septum, to the sample and (2) allows the sample position to be adjusted while keeping the chamber fixed and hermetic during the experiment.

  18. New anaerobic process of nitrogen removal.

    PubMed

    Kalyuzhnyi, S; Gladchenko, M; Mulder, A; Versprille, B

    2006-01-01

    This paper reports on successful laboratory testing of a new nitrogen removal process called DEAMOX (DEnitrifying AMmonium OXidation) for the treatment of strong nitrogenous wastewater such as baker's yeast effluent. The concept of this process combines the recently discovered ANAMMOX (ANaerobic AMMonium OXidation) reaction with autotrophic denitrifying conditions using sulfide as an electron donor for the production of nitrite within an anaerobic biofilm. The achieved results with a nitrogen loading rate of higher than 1,000 mg/L/d and nitrogen removal of around 90% look very promising because they exceed (by 9-18 times) the corresponding nitrogen removal rates of conventional activated sludge systems. The paper describes also some characteristics of DEAMOX sludge, as well as the preliminary results of its microbiological characterization. PMID:17163025

  19. Potential for anaerobic treatment of whey

    SciTech Connect

    Schlottfeldt, G.A.B.

    1980-01-01

    Results of experiments on 3 laboratory-scale reactors loaded with whey at different daily rates showed that a daily loading of 85 lb COD/1000 cubic feet achieved a COD reduction efficiency of 86% with a gas yield (50% methane) of 5 cubic feet/gal of treated whey. High microorganism population and pH control were essential for stable operation. Overall 1st order COD removal rate constants were 1.13, 0.70 and 1.73/day at 35, 50 and 60 degrees Celcius respectively. The economic impact of anaerobic whey treatment was evaluated for small, medium and large cheese plants, and annual operating costs were projected for a 20-year period. Among several systems that were compared, the anaerobic treatment of whey was shown to be the only one that had a potential of paying for itself. Treatment costs represented from 0.85 to 2.6% of the mean US milk price to producers.

  20. Note: Small anaerobic chamber for optical spectroscopy

    SciTech Connect

    Chauvet, Adrien A. P. Chergui, Majed; Agarwal, Rachna; Cramer, William A.

    2015-10-15

    The study of oxygen-sensitive biological samples requires an effective control of the atmosphere in which they are housed. In this aim however, no commercial anaerobic chamber is adequate to solely enclose the sample and small enough to fit in a compact spectroscopic system with which analysis can be performed. Furthermore, spectroscopic analysis requires the probe beam to pass through the whole chamber, introducing a requirement for adequate windows. In response to these challenges, we present a 1 l anaerobic chamber that is suitable for broad-band spectroscopic analysis. This chamber has the advantage of (1) providing access, via a septum, to the sample and (2) allows the sample position to be adjusted while keeping the chamber fixed and hermetic during the experiment.

  1. Recent developments in anaerobic membrane reactors.

    PubMed

    Stuckey, David C

    2012-10-01

    Anaerobic membrane reactors (AnMBRs) have recently evolved from aerobic MBRs, with the membrane either external or submerged within the reactor, and can achieve high COD removals (~98%) at hydraulic retention times (HRTs) as low as 3 h. Since membranes stop biomass being washed out, they can enhance performance with inhibitory substrates, at psychrophilic/thermophilic temperatures, and enable nitrogen removal via Anammox. Fouling is important, but addition of activated carbon or resins/precipitants can remove soluble microbial products (SMPs)/colloids and enhance flux. Due to their low energy use and solids production, and solids free effluent, they can enhance nutrient and water recycling. Nevertheless, more work is needed to: compare fouling between aerobic and anaerobic systems; determine how reactor operation influences fouling; evaluate the effect of different additives on membrane fouling; determine whether nitrogen removal can be incorporated into AnMBRs; recover methane solubility from low temperatures effluents; and, establish sound mass and energy balances. PMID:22749372

  2. Running-based Anaerobic Sprint Test as a Procedure to Evaluate Anaerobic Power.

    PubMed

    Andrade, V L; Zagatto, A M; Kalva-Filho, C A; Mendes, O C; Gobatto, C A; Campos, E Z; Papoti, M

    2015-12-01

    The aim of this study was to evaluate the use of the running anaerobic sprint test (RAST) as a predictor of anaerobic capacity, compare it to the maximal accumulated oxygen deficit (MAOD) and to compare the RAST's parameters with the parameters of 30-s all-out tethered running on a treadmill. 39 (17.0±1.4 years) soccer players participated in this study. The participants underwent an incremental test, 10 submaximal efforts [50-95% of velocity correspondent to VO(2MAX) (vVO(2MAX))] and one supramaximal effort at 110% of vVO(2MAX) for the determination of MAOD. Furthermore, the athletes performed the RAST. In the second stage the 30-s all-out tethered running was performed on a treadmill (30-s all-out), and compared with RAST. No significant correlation was observed between MAOD and RAST parameters. However, significant correlations were found between the power of the fifth effort (P5) of RAST with peak and mean power of 30-s all-out (r=0.73 and 0.50; p<0.05, respectively). In conclusion, the parameters from RAST do not have an association with MAOD, suggesting that this method should not be used to evaluate anaerobic capacity. Although the correlations between RAST parameters with 30-s all-out do reinforce the RAST as an evaluation method of anaerobic metabolism, such as anaerobic power. PMID:26422055

  3. Hog farm in California uses anaerobic digestion

    SciTech Connect

    Swanson, D.

    1995-12-31

    This article describes a system of covered lagoons which help address the waste management problems of hog farmers as well as producing methane used to power generators. Four advantages of anaerobic digestion are described along with the system: energy production from methane; fertilizer for fields; economic development in rural areas; and improved water quality through reduction of nonpoint source pollution. Address for full report is given.

  4. Anaerobic biodegradation of surrogate naphthenic acids.

    PubMed

    Clothier, Lindsay N; Gieg, Lisa M

    2016-03-01

    Surface bitumen extraction from the Alberta's oil sands region generates large settling basins known as tailings ponds. The oil sands process-affected water (OSPW) stored in these ponds contain solid and residual bitumen-associated compounds including naphthenic acids (NAs) that can potentially be biodedgraded by indigenous tailings microorganisms. While the biodegradation of some NAs is known to occur under aerobic conditions, little is understood about anaerobic NA biodegradation even though tailings ponds are mainly anoxic. Here, we investigated the potential for anaerobic NA biodegradation by indigenous tailings microorganisms. Enrichment cultures were established from anoxic tailings that were amended with 5 single-ringed surrogate NAs or acid-extractable organics (AEO) from OSPW and incubated under nitrate-, sulfate-, iron-reducing, and methanogenic conditions. Surrogate NA depletion was observed under all anaerobic conditions tested to varying extents, correlating to losses in the respective electron acceptor (sulfate or nitrate) or the production of predicted products (Fe(II) or methane). Tailings-containing cultures incubated under the different electron-accepting conditions resulted in the enrichment and putative identification of microbial community members that may function in metabolizing surrogate NAs under the various anoxic conditions. In addition, more complex NAs (in the form of AEO) was observed to drive sulfate and iron reduction relative to controls. Overall, this study has shown that simple surrogate NAs can be biodegraded under a variety of anoxic conditions, a key first step in understanding the potential anaerobic metabolism of NAs in oil sands tailings ponds and other industrial wastewaters. PMID:26724449

  5. Anaerobic Life at Extremely High Temperatures

    NASA Astrophysics Data System (ADS)

    Stetter, Karl O.

    1984-12-01

    Continental and submarine solfataric fields turned out to contain various extremely thermophilic anaerobic organisms which all belong to the archaebacteria. They are living autotrophically on sulphur, hydrogen and CO2 or by methanogenesis or heterotrophically on different organic substrates by sulphur respiration or, less frequently, by fermentation. The most extremely thermophilic isolates are growing between 80 and 110°C with an optimum around 105°C.

  6. Anaerobic expanded bed treatment of whey

    SciTech Connect

    Switzenbaum, M.S.; Danskin, S.C.

    1982-01-01

    The use of anaerobic attached film expanded bed (AAFEB) for whey treatment is described and the potential for implementation of substitute natural gas from whey is discussed. A significant portion (less than or equal to 46%) of the energy needs at cheese-production plants could be recovered by CH/sub 4/ manufactured from whey. Efficient treatment of whey is possible by AAFEB at low retention times and at high organic loading rates.

  7. Anaerobic methane oxidation on the Amazon shelf

    SciTech Connect

    Blair, N.E.; Aller, R.C.

    1995-09-01

    Anaerobic methane oxidation on the Amazon shelf is strongly controlled by dynamic physical sedimentation processes. Rapidly accumulating, physically reworked deltaic sediments characteristic of much of the shelf typically support what appear to be low rates of steady state anaerobic methane oxidation at depths of 5-8 m below the sediment-water interface. Methane oxidation in these cases is responsible for < {approximately}10% of the {Sigma}CO{sub 2} inventory in the oxidation zone and is limited largely by the steady-state diffusive flux of methane into the overlying sulfate reduction zone. In contrast, a large area of the shelf has been extensively eroded, reexposing once deeply buried (>10 m) methane-charged sediment directly to seawater. In this nonsteady-state situation, methane is a major source of recently produced {Sigma}CO{sub 2} and an important reductant for sulfate. These observations suggest that authigenic sedimentary carbonates derived from anaerobic methane oxidation may sometimes reflect physically enhanced nonsteady-state exposure of methane to sulfate in otherwise biogeochemically unreactive deposits. The concentration profiles of CH{sub 4}, SO{sub 4}{sup =}, and {Sigma}CO{sub 2} in the eroded deposit were reproduced by a coupled reaction-transport model. This area of the shelf was reexposed to seawater approximately 5-10 years ago based on the model results and the assumption that the erosion of the deposit occurred as a single event that has now ceased. The necessary second order rate constant for anaerobic methane oxidation was {le}0.1 mM{sup -1} d{sup -1}.

  8. Mathematical modelling of the anaerobic hybrid reactor.

    PubMed

    Soroa, S; Gomez, J; Ayesa, E; Garcia-Heras, J L

    2006-01-01

    This paper presents a new mathematical model for the anaerobic hybrid reactor (AHR) (a UASB reactor and an anaerobic filter in series) and its experimental calibration and verification. The model includes a biochemical part and a mass transport one, which considers the AHR as two contact reactors in series. The anaerobic process transformations are described by the model developed by Siegrist et al. The fraction (F) of solids in the clarification zone of the UASB reactor that leaves this first reactor is the key physical parameter to be estimated. The main parameters of the model were calibrated using experimental results from a bench-scale AHR fed with real slaughterhouse wastewater. The fraction of inert particulate COD in the influent and the factor F were estimated by a trial and error procedure comparing experimental and simulated results of the mass of solids in the lower tank and the VSS concentration in the AHR effluent. A good fit was obtained. The final verification was carried out by comparing a set of experiments with simulated data. The model's capability to predict the process performance was thus proved. PMID:16939085

  9. Alternating Current Influences Anaerobic Electroactive Biofilm Activity.

    PubMed

    Wang, Xin; Zhou, Lean; Lu, Lu; Lobo, Fernanda Leite; Li, Nan; Wang, Heming; Park, Jaedo; Ren, Zhiyong Jason

    2016-09-01

    Alternating current (AC) is known to inactivate microbial growth in suspension, but how AC influences anaerobic biofilm activities has not been systematically investigated. Using a Geobacter dominated anaerobic biofilm growing on the electrodes of microbial electrochemical reactors, we found that high frequency AC ranging from 1 MHz to 1 kHz (amplitude of 5 V, 30 min) showed only temporary inhibition to the biofilm activity. However, lower frequency (100 Hz, 1.2 or 5 V) treatment led to 47 ± 19% permanent decrease in limiting current on the same biofilm, which is attributed to the action of electrohydrodynamic force that caused biofilm damage and loss of intercellular electron transfer network. Confocal microscopy images show such inactivation mainly occurred at the interface between the biofilm and the electrode. Reducing the frequency further to 1 Hz led to water electrolysis, which generated gas bubbles that flushed all attached cells out of the electrode. These findings provide new references on understanding and regulating biofilm growth, which has broader implications in biofouling control, anaerobic waste treatment, energy and product recovery, and general understanding of microbial ecology and physiology. PMID:27485403

  10. Anaerobic O-demethylation of phenylmethylethers

    SciTech Connect

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

    1990-01-01

    Anaerobic O-demethylation (AOD) of phenylmethylethers is a process of both basic and applied significance. The aryl-O-methyl ethers are abundant in natural products, particularly as components of lignin. They are present as methoxylated lignin monomers in anaerobic environments and can be completely degraded there by mixed microbial populations. AOD is an essential early step in this process, and it is also a key reaction in the utilization of the O-methyl substituent as a C-one substrate by acetogens. An understanding of the AOD reaction mechanism might suggest new ways in which chemicals could be derived from lignocellulosic materials. The biochemical mechanism for the anaerobic cleavage of the aryl-O-methyl ether bond is an intriguing, but relatively unexplored process. In contrast to aerobic O-demethylating enzymes, AOD appears to involve methyl group transfer. Thus, novel biochemical information on an important biotransformation reaction will be gained from the research proposed. Recently, we have shown that AOD activity is inducible and have developed an assay for detecting AOD activity in cell-free extracts of Acetobacterium woodii. AOD activity is stimulated in vitro by the addition of ATP (1mM) and pyruvate (30 mM), the K{sub M} for vanillate being 0.4 mM. In collaboration with protein purification experts, we proposed to purify the AOD enzyme and characterize the protein(s) and the enzymatic reaction involved. 8 figs., 5 tabs.

  11. Anaerobic Treatment of Palm Oil Mill Effluent in Pilot-Scale Anaerobic EGSB Reactor.

    PubMed

    Wang, Jin; Mahmood, Qaisar; Qiu, Jiang-Ping; Li, Yin-Sheng; Chang, Yoon-Seong; Li, Xu-Dong

    2015-01-01

    Large volumes of untreated palm oil mill effluent (POME) pose threat to aquatic environment due to the presence of very high organic content. The present investigation involved two pilot-scale anaerobic expanded granular sludge bed (EGSB) reactors, continuously operated for 1 year to treat POME. Setting HRT at 9.8 d, the anaerobic EGSB reactors reduced COD from 71179 mg/L to 12341 mg/L and recycled half of sludge by a dissolved air flotation (DAF). The average effluent COD was 3587 mg/L with the consistent COD removal efficiency of 94.89%. Adding cationic polymer (PAM) dose of 30 mg/L to DAF unit and recycling its half of sludge caused granulation of anaerobic sludge. Bacilli and small coccid bacteria were the dominant microbial species of the reactor. The reactor produced 27.65 m(3) of biogas per m(3) of POME which was utilized for electricity generation. PMID:26167485

  12. Evaluation of a microtiter system for identification of anaerobic bacteria.

    PubMed Central

    Savuto, P S; Ellner, P D

    1984-01-01

    The Anaerobe Combo Panel (American MicroScan, Mahwah, N.J.) was evaluated for its ability to identify anaerobic bacteria. The frozen, 96-well panel utilizes 24 biochemical reactions and four antimicrobial agents for species identification. The Anaerobe Combo Panel was used to test 114 clinical isolates of strict anaerobes. Reactions were read after 48 h, and the results were compared with those obtained with the PRAS II system (Scott Laboratories, Inc., Fiskeville, R.I.). Discrepancies between the two systems were resolved by gas-liquid chromatography. With the Anaerobe Combo Panel, 84% of the organisms were able to grow, and 89% of these were correctly identified to genus level and 78% to species level. The Anaerobe Combo Panel was easy to inoculate and read, but some of the reactions were difficult to interpret, and not all of the derived codes were found in the code book. PMID:6378969

  13. The aerobic and anaerobic bacteriology of perirectal abscesses.

    PubMed Central

    Brook, I; Frazier, E H

    1997-01-01

    The microbiology of perirectal abscesses in 144 patients was studied. Aerobic or facultative bacteria only were isolated in 13 (9%) instances, anaerobic bacteria only were isolated in 27 (19%) instances, and mixed aerobic and anaerobic flora were isolated in 104 (72%) instances. A total of 325 anaerobic and 131 aerobic or facultative isolates were recovered (2.2 anaerobic isolates and 0.9 aerobic isolates per specimen). The predominant anaerobes were as follows: Bacteroides fragilis group (85 isolates), Peptostreptococcus spp. (72 isolates), Prevotella spp. (71 isolates), Fusobacterium spp. (21 isolates), Porphyromonas spp. (20 isolates), and Clostridium spp. (15 isolates). The predominant aerobic and facultative bacteria were as follows: Staphylococcus aureus (34 isolates), Streptococcus spp. (28 isolates), and Escherichia coli (19 isolates). These data illustrate the polymicrobial aerobic and anaerobic microbiology of perirectal abscesses. PMID:9350771

  14. Aerobic and anaerobic cellulase production by Cellulomonas uda.

    PubMed

    Poulsen, Henrik Vestergaard; Willink, Fillip Wolfgang; Ingvorsen, Kjeld

    2016-10-01

    Cellulomonas uda (DSM 20108/ATCC 21399) is one of the few described cellulolytic facultative anaerobes. Based on these characteristics, we initiated a physiological study of C. uda with the aim to exploit it for cellulase production in simple bioreactors with no or sporadic aeration. Growth, cellulase activity and fermentation product formation were evaluated in different media under both aerobic and anaerobic conditions and in experiments where C. uda was exposed to alternating aerobic/anaerobic growth conditions. Here we show that C. uda behaves as a true facultative anaerobe when cultivated on soluble substrates such as glucose and cellobiose, but for reasons unknown cellulase activity is only induced under aerobic conditions on insoluble cellulosic substrates and not under anaerobic conditions. These findings enhance knowledge on the limited number of described facultative cellulolytic anaerobes, and in addition it greatly limits the utility of C. uda as an 'easy to handle' cellulase producer with low aeration demands. PMID:27154570

  15. Clinical review: Bacteremia caused by anaerobic bacteria in children

    PubMed Central

    Brook, Itzhak

    2002-01-01

    This review describes the microbiology, diagnosis and management of bacteremia caused by anaerobic bacteria in children. Bacteroides fragilis, Peptostreptococcus sp., Clostridium sp., and Fusobacterium sp. were the most common clinically significant anaerobic isolates. The strains of anaerobic organisms found depended, to a large extent, on the portal of entry and the underlying disease. Predisposing conditions include: malignant neoplasms, immunodeficiencies, chronic renal insufficiency, decubitus ulcers, perforation of viscus and appendicitis, and neonatal age. Organisms identical to those causing anaerobic bacteremia can often be recovered from other infected sites that may have served as a source of persistent bacteremia. When anaerobes resistant to penicillin are suspected or isolated, antimicrobial drugs such as clindamycin, chloramphenicol, metronidazole, cefoxitin, a carbapenem, or the combination of a beta-lactamase inhibitor and a penicillin should be administered. The early recognition of anaerobic bacteremia and administration of appropriate antimicrobial and surgical therapy play a significant role in preventing mortality and morbidity in pediatric patients. PMID:12133179

  16. Anaerobic Metabolism and Bioremediation of Explosives-Contaminated Soil

    NASA Astrophysics Data System (ADS)

    Boopathy, Raj

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

  17. Application of Anaerobic Digestion Model No. 1 for simulating anaerobic mesophilic sludge digestion

    SciTech Connect

    Mendes, Carlos Esquerre, Karla Matos Queiroz, Luciano

    2015-01-15

    Highlights: • The behavior of a anaerobic reactor was evaluated through modeling. • Parametric sensitivity analysis was used to select most sensitive of the ADM1. • The results indicate that the ADM1 was able to predict the experimental results. • Organic load rate above of 35 kg/m{sup 3} day affects the performance of the process. - Abstract: Improving anaerobic digestion of sewage sludge by monitoring common indicators such as volatile fatty acids (VFAs), gas composition and pH is a suitable solution for better sludge management. Modeling is an important tool to assess and to predict process performance. The present study focuses on the application of the Anaerobic Digestion Model No. 1 (ADM1) to simulate the dynamic behavior of a reactor fed with sewage sludge under mesophilic conditions. Parametric sensitivity analysis is used to select the most sensitive ADM1 parameters for estimation using a numerical procedure while other parameters are applied without any modification to the original values presented in the ADM1 report. The results indicate that the ADM1 model after parameter estimation was able to predict the experimental results of effluent acetate, propionate, composites and biogas flows and pH with reasonable accuracy. The simulation of the effect of organic shock loading clearly showed that an organic shock loading rate above of 35 kg/m{sup 3} day affects the performance of the reactor. The results demonstrate that simulations can be helpful to support decisions on predicting the anaerobic digestion process of sewage sludge.

  18. [Distribution and removal of anaerobic antibiotic resistant bacteria during mesophilic anaerobic digestion of sewage sludge].

    PubMed

    Tong, Juan; Wang, Yuan-Yue; Wei Yuan, Song

    2014-10-01

    Sewage sludge is one of the major sources that releasing antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARG) into the environment since it contains large amount of ARB, but there is little information about the fate of the anaerobic ARB in the anaerobic digestion of sewage sludge. Therefore, the distribution, removal and seasonal changes of tetracycline and β-lactam antibiotics resistant bacteria in the mesophilic egg-shaped digesters of a municipal wastewater treatment plant were investigated for one year in this study. Results showed that there were higher amounts of ARB and higher resistance rate of β-lactam antibiotics than that of tetracycline antibiotics in the sewage sludge. All ARB could be significantly reduced during the mesophilic anaerobic digestion process by 1.48-1.64 log unit (P < 0.05). Notably, the ampicillin and cephalothin resistance rates were significantly increased after anaerobic digestion by 12.0% and 14.3%, respectively (P < 0.05). The distribution of ARB in the sewage sludge had seasonal change characteristics. Except for chlorotetracycline resistant bacteria, there were more ARB in the sewage sludge in cold season than in warm season (P < 0.05). PMID:25693388

  19. Oxygen tolerance capacity of upflow anaerobic solid-state (UASS) with anaerobic filter (AF) system.

    PubMed

    Meng, Yao; Jost, Carsten; Mumme, Jan; Wang, Kaijun; Linke, Bernd

    2016-07-01

    In order to investigate the oxygen tolerance capacity of upflow anaerobic solid-state (UASS) with anaerobic filter (AF) system, the effect of microaeration on thermophilic anaerobic digestion of maize straw was investigated under batch conditions and in the UASS with AF system. Aeration intensities of 0-431mL O2/gvs were conducted as pretreatment under batch conditions. Aeration pretreatment obviously enhanced anaerobic digestion and an aeration intensity of 431mL O2/gvs increased the methane yield by 82.2%. Aeration intensities of 0-355mL O2/gvs were conducted in the process liquor circulation of the UASS with AF system. Dissolved oxygen (DO) of UASS and AF reactors kept around 1.39±0.27 and 0.99±0.38mg/L, respectively. pH was relatively stable around 7.11±0.04. Volatile fatty acids and soluble chemical oxygen demand concentration in UASS reactor were higher than those in AF reactor. Methane yield of the whole system was almost stable at 85±7mL/gvs as aeration intensity increased step by step. The UASS with AF system showed good oxygen tolerance capacity. PMID:27372134

  20. Anaerobic capacity: a maximal anaerobic running test versus the maximal accumulated oxygen deficit.

    PubMed

    Maxwell, N S; Nimmo, M A

    1996-02-01

    The present investigation evaluates a maximal anaerobic running test (MART) against the maximal accumulated oxygen deficit (MAOD) for the determination of anaerobic capacity. Essentially, this involved comparing 18 male students performing two randomly assigned supramaximal runs to exhaustion on separate days. Post warm-up and 1, 3, and 6 min postexercise capillary blood samples were taken during both tests for plasma blood lactate (BLa) determination. In the MART only, blood ammonia (BNH3) concentration was measured, while capillary blood samples were additionally taken after every second sprint for BLa determination. Anaerobic capacity, measured as oxygen equivalents in the MART protocol, averaged 112.2 +/- 5.2 ml.kg-1.min-1. Oxygen deficit, representing the anaerobic capacity in the MAOD test, was an average of 74.6 +/- 7.3 ml.kg-1. There was a significant correlation between the MART and MAOD (r = .83, p < .001). BLa values obtained over time in the two tests showed no significant difference, nor was there any difference in the peak BLa recorded. Peak BNH3 concentration recorded was significantly increased from resting levels at exhaustion during the MART. PMID:8664845

  1. Horse manure as feedstock for anaerobic digestion.

    PubMed

    Hadin, Sa; Eriksson, Ola

    2016-10-01

    Horse keeping is of great economic, social and environmental benefit for society, but causes environmental impacts throughout the whole chain from feed production to manure treatment. According to national statistics, the number of horses in Sweden is continually increasing and is currently approximately 360,000. This in turn leads to increasing amounts of horse manure that have to be managed and treated. Current practices could cause local and global environmental impacts due to poor performance or lack of proper management. Horse manure with its content of nutrients and organic material can however contribute to fertilisation of arable land and recovery of renewable energy following anaerobic digestion. At present anaerobic digestion of horse manure is not a common treatment. In this paper the potential for producing biogas and biofertiliser from horse manure is analysed based on a thorough literature review in combination with mathematical modelling and simulations. Anaerobic digestion was chosen as it has a high degree of resource conservation, both in terms of energy (biogas) and nutrients (digestate). Important factors regarding manure characteristics and operating factors in the biogas plant are identified. Two crucial factors are the type and amount of bedding material used, which has strong implications for feedstock characteristics, and the type of digestion method applied (dry or wet process). Straw and waste paper are identified as the best materials in an energy point of view. While the specific methane yield decreases with a high amount of bedding, the bedding material still makes a positive contribution to the energy balance. Thermophilic digestion increases the methane generation rate and yield, compared with mesophilic digestion, but the total effect is negligible. PMID:27396682

  2. Anaerobic wastewater treatment of concentrated sewage using a two-stage upflow anaerobic sludge blanket- anaerobic filter system.

    PubMed

    Halalsheh, Maha M; Abu Rumman, Zainab M; Field, Jim A

    2010-01-01

    A two-stage pilot-scale upflow anaerobic sludge blanket - anaerobic filter (UASB-AF) reactors system treating concentrated domestic sewage was operated at 23 degrees C and at hydraulic retention times (HRT) of 15 and 4 h, respectively. Excess sludge from the downstream AF stage was returned to the upstream UASB reactor. The aim was to obtain higher sludge retention time (SRT) in the UASB reactor for better methanization of suspended COD. The UASB-AF system removed 55% and 65% of the total COD (COD(tot)) and suspended COD (COD(ss)), respectively. The calculated SRT in the UASB reactor ranged from 20-35 days. The AF reactor removed the washed out sludge from the first stage reactor with average COD(ss) removal efficiency of 55%. The volatile fatty acids concentration in the effluent of the AF was 39 mg COD/L compared with 78 mg COD/L measured for the influent. The slightly higher COD(tot) removal efficiency obtained in this study compared with a single stage UASB reactor was achieved at 17% reduction in the total volume. PMID:20390881

  3. Anaerobic bioprocessing of low rank coals

    SciTech Connect

    Jain, M.K.; Narayan, R.; Han, O.

    1991-01-01

    The overall goal of this project is to find biological methods to remove carboxylic functionalities from low rank coals under ambient conditions and to assess the properties of these modified coals towards coal liquefaction. The main objectives for this quarter were: (1) enrichment of anaerobic microbial consortia in a coal fed chemostat, (2) characterization of biocoal products and examination of liquefaction potential, (3) isolation of decarboxylating organisms and evaluation of the isolated organisms for decarboxylation. The project began on September 12, 1990. 3 figs., 7 tabs.

  4. Identification, distribution, and toxigenicity of obligate anaerobes in polluted waters.

    PubMed Central

    Daily, O P; Joseph, S W; Gillmore, J D; Colwell, R R; Seidler, R J

    1981-01-01

    A seasonal occurrence of obligately anaerobic bacteria, predominantly of the genera Bacteroides and Clostridium, in a polluted water site has been observed. The number of anaerobes varied from 1.8 X 10(3) cells/ml in the warmer months to 10 cells/ml in winter. Several isolates were toxigenic, indicating a potential human health hazard. PMID:7235706

  5. TEST RESULTS FOR FUEL CELL OPERATION ON ANAEROBIC DIGESTER GAS

    EPA Science Inventory

    EPA, in conjunction with ONSI Corp., embarked on a project to define, design, test, and assess a fuel cell energy recovery system for application at anaerobic digester waste water (sewage) treatment plants. Anaerobic digester gas (ADG) is produced at these plants during the proce...

  6. Anaerobic Catabolism of Aromatic Compounds: a Genetic and Genomic View

    PubMed Central

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

    2009-01-01

    Summary: Aromatic compounds belong to one of the most widely distributed classes of organic compounds in nature, and a significant number of xenobiotics belong to this family of compounds. Since many habitats containing large amounts of aromatic compounds are often anoxic, the anaerobic catabolism of aromatic compounds by microorganisms becomes crucial in biogeochemical cycles and in the sustainable development of the biosphere. The mineralization of aromatic compounds by facultative or obligate anaerobic bacteria can be coupled to anaerobic respiration with a variety of electron acceptors as well as to fermentation and anoxygenic photosynthesis. Since the redox potential of the electron-accepting system dictates the degradative strategy, there is wide biochemical diversity among anaerobic aromatic degraders. However, the genetic determinants of all these processes and the mechanisms involved in their regulation are much less studied. This review focuses on the recent findings that standard molecular biology approaches together with new high-throughput technologies (e.g., genome sequencing, transcriptomics, proteomics, and metagenomics) have provided regarding the genetics, regulation, ecophysiology, and evolution of anaerobic aromatic degradation pathways. These studies revealed that the anaerobic catabolism of aromatic compounds is more diverse and widespread than previously thought, and the complex metabolic and stress programs associated with the use of aromatic compounds under anaerobic conditions are starting to be unraveled. Anaerobic biotransformation processes based on unprecedented enzymes and pathways with novel metabolic capabilities, as well as the design of novel regulatory circuits and catabolic networks of great biotechnological potential in synthetic biology, are now feasible to approach. PMID:19258534

  7. LOVES CREEK ANAEROBIC, UPFLOW (ANFLOW) PILOT PLANT: PERFORMANCE SUMMARY

    EPA Science Inventory

    Anaerobic filter technology for municipal wastewater treatment has been studied in Knoxville, Tennessee with a 190-m exp 3 /d facility from August 1981 to October 1983. The ORNL project (described by the acronym ANFLOW for the anaerobic, upflow characteristics of the technology) ...

  8. Evidence of hydrolytic route for anaerobic cyanide degradation.

    PubMed Central

    Fallon, R D

    1992-01-01

    Products observed during anaerobic cyanide transformation are consistent with a hydrolytic pathway (HCN + H2O <--> HCONH2 + H2O <--> HCOOH + NH3). Formate, the most frequently observed product, was generally converted to bicarbonate. Formamide was rapidly hydrolyzed to formate upon exposure to the anaerobic consortium but was not detected as an intermediate of cyanide transformation. PMID:1444430

  9. Denitrification in anaerobic lagoons used to treat swine wastewater.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic lagoons are commonly used for treatment of swine wastewater. Although these lagoons were once thought to be relatively simple; their physical, chemical, and biological processes are actually very complex. This study of anaerobic lagoons had twofold objectives: 1] quantify denitrification e...

  10. Anaerobic Soil Disinfestation and Soil Borne Pest Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic soil disinfestation (ASD; also referred to as Biological Soil Disinfestation (BSD)) is a pre-plant soil treatment method developed to control plant disease and manage yield decline in many crop production systems. The practice involves induction of anaerobic soil conditions by increasing m...

  11. Anaerobic Threshold and Salivary α-amylase during Incremental Exercise

    PubMed Central

    Akizuki, Kazunori; Yazaki, Syouichirou; Echizenya, Yuki; Ohashi, Yukari

    2014-01-01

    [Purpose] The purpose of this study was to clarify the validity of salivary α-amylase as a method of quickly estimating anaerobic threshold and to establish the relationship between salivary α-amylase and double-product breakpoint in order to create a way to adjust exercise intensity to a safe and effective range. [Subjects and Methods] Eleven healthy young adults performed an incremental exercise test using a cycle ergometer. During the incremental exercise test, oxygen consumption, carbon dioxide production, and ventilatory equivalent were measured using a breath-by-breath gas analyzer. Systolic blood pressure and heart rate were measured to calculate the double product, from which double-product breakpoint was determined. Salivary α-amylase was measured to calculate the salivary threshold. [Results] One-way ANOVA revealed no significant differences among workloads at the anaerobic threshold, double-product breakpoint, and salivary threshold. Significant correlations were found between anaerobic threshold and salivary threshold and between anaerobic threshold and double-product breakpoint. [Conclusion] As a method for estimating anaerobic threshold, salivary threshold was as good as or better than determination of double-product breakpoint because the correlation between anaerobic threshold and salivary threshold was higher than the correlation between anaerobic threshold and double-product breakpoint. Therefore, salivary threshold is a useful index of anaerobic threshold during an incremental workload. PMID:25140097

  12. Treatment of slaughterhouse wastewaters using anaerobic filters.

    PubMed

    Martinez, Sandra Luz; Torretta, Vincenzo; Minguelac, Jésus Vázquez; Siñeriz, Faustino; Raboni, Massimo; Copelli, Sabrina; Rada, Elena Cristina; Ragazzi, Marco

    2014-01-01

    In this paper, a laboratory-scale experimentation allowed comparing the performances of two upflow anaerobic packed-bed filters filled with different packing materials and operating at mesophilic conditions (30 degreeC) for treating slaughterhouse wastewaters. Methane production was experimentally evaluated considering different volumetric organic loading rates as well as feeding overloading conditions. Although filter performances declined with loading rates higher than 6 kg CODin m-3 d-1 , the chemical oxygen demand (COD) removal efficiency remained always above 60%. The experimental results allowed for determining kinetic parameters for bacterial growth rate and methane production, following Monod and Chen-Hashimoto models, respectively. Results demonstrated that the reactors reached a cellular retention time significantly greater than the hydraulic retention time. The kinetic parameter values (Ks, l/max) revealed the low microorganisms' affinity for the substrate and confirmed the moderate biodegradability of slaughterhouse wastewater. The kinetic analysis also allowed the comparison of the filters performances with another anaerobic system and the assessment of the parameters useful for real-scale plant design. The system design, applied to a medium-sized Argentinean slaughterhouse, demonstrated to (i) be energetically self-sufficient and (ii) contribute to the plant's water heating requirements. PMID:24600871

  13. The anaerobic digestion of solid organic waste.

    PubMed

    Khalid, Azeem; Arshad, Muhammad; Anjum, Muzammil; Mahmood, Tariq; Dawson, Lorna

    2011-08-01

    The accumulation of solid organic waste is thought to be reaching critical levels in almost all regions of the world. These organic wastes require to be managed in a sustainable way to avoid depletion of natural resources, minimize risk to human health, reduce environmental burdens and maintain an overall balance in the ecosystem. A number of methods are currently applied to the treatment and management of solid organic waste. This review focuses on the process of anaerobic digestion which is considered to be one of the most viable options for recycling the organic fraction of solid waste. This manuscript provides a broad overview of the digestibility and energy production (biogas) yield of a range of substrates and the digester configurations that achieve these yields. The involvement of a diverse array of microorganisms and effects of co-substrates and environmental factors on the efficiency of the process has been comprehensively addressed. The recent literature indicates that anaerobic digestion could be an appealing option for converting raw solid organic wastes into useful products such as biogas and other energy-rich compounds, which may play a critical role in meeting the world's ever-increasing energy requirements in the future. PMID:21530224

  14. Kinetics of anaerobic purification of industrial wastewater

    SciTech Connect

    Bolle, W.L.; van Breugel, J.; van Eybergen, G.C.; Kossen, N.W.F.; van Gils, W.

    1986-04-01

    As part of the development of an integral mathematical model describing the up-flow anaerobic sludges blanket (UASB) reactor, the kinetics of the conversion of organic wastes has to be known. The Mondod model is compared with the model proposed by Andrews, et al. Together with the assumption that the substrate for the anaerobic bacteria is formed by nonionized, volatile fatty acids, the Andrews model is able to describe substrate inhibition and reactor failure due to pH changes. From four batch experiments, with different concentrations of microorganisms, it could be concluded with a reliability of over 95% that the Monod model was inadequate and Andrews' model was adequate to describe the measurements. Standard statistical techniques like the X2 and the F-test were used for this purpose. From a parameter sensitivity analysis for the Andrews model it followed that the maximum specific growth rate Mu(A) max of the bacteria and the inhibition constant K, are the parameters which influance the systems most. Thus, these parameters were determined experimentally and most accurately. The other parameters were taken from literature. From a calculation of the Thiele modulus for the particles it follows that transport limitation of the substrate in the flocs is not significant. The efficiency Eta is 0.85 in the worst case. 11 references.

  15. Anaerobic expanded bed treatment of whey

    SciTech Connect

    Switzenbaum, M.S.; Danskin, S.C.

    1982-01-01

    Anaerobic treatment of whey offers the dual advantage of energy production and pollution control. The energy produced is in the form of methane which is a valuable form of energy in that it is easily separated from the liquid digesting whey, has a high caloric value and can be used for heating and cooking at the cheese plants where it is produced. Based on the data of a survey conducted by the New York State Energy Research and Development Authority, it was shown that a significant portion (up to 46%) of the energy needs (in natural gas and oil) at cheese production plants in New York State could be recovered by methane generated from whey produced as a by-product of cheese manufacturing at the plants. Finally, the results of a preliminary feasibility study of a new type of innovative, compact, high rate, anaerobic fixed film process show that efficient treatment of whey is possible at low retention times, and at high organic loading rates.

  16. Anaerobic biodegradation of hexazinone in four sediments.

    PubMed

    Wang, Huili; Xu, Shuxia; Tan, Chengxia; Wang, Xuedong

    2009-05-30

    Anaerobic biodegradation of hexazinone was investigated in four sediments (L1, L2, Y1 and Y2). Results showed that the L2 sediment had the highest biodegradation potential among four sediments. However, the Y1 and Y2 sediments had no capacity to biodegrade hexazinone. Sediments with rich total organic carbon, long-term contamination history by hexazinone and neutral pH may have a high biodegradation potential because the former two factors can induce the growth of microorganisms responsible for biodegradation and the third factor can offer suitable conditions for biodegradation. The addition of sulfate or nitrate as electron acceptors enhanced hexazinone degradation. As expected, the addition of electron donors (lactate, acetate or pyruvate) substantially inhibited the degradation. In natural environmental conditions, the effect of intermediate A [3-(4-hydroxycyclohexyl)-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H, 3H)dione] on anaerobic hexazinone degradation was negligible because of its low level. PMID:18824297

  17. Anaerobic degradation kinetics of a cholesteryl ester.

    PubMed

    Gutiérrez, S; Viñas, M

    2003-01-01

    The most important components of wool scouring effluent grease are esters of sterols. Cholesteryl palmitate (CP) is the main ester in this grease. In this paper, the influence of the ester concentration in the anaerobic digestion and the relative rate of the different degradation steps, are studied. The experiment was carried out to measure methane production in the anaerobic degradation of acetate, palmitic acid (PA) and CP. A first-order kinetic model was assumed for hydrolysis and Monod models were assumed for both the methanogenic and acetogenic steps. Maximum hydrolysis rate was found to be around 20 times faster than the maximum methanogenic reaction rate during the experience. The lanolin emulsion drop size effect was also evaluated employing fine and coarse stock lanolin emulsions and no adapted sludge. Concentrations of 13.7 to 4.6 gCOD x l(-1) were employed. In a previous study, the effect of palmitic acid emulsion size was found important when similar sludge was tested. When esters are degraded, a significant effect of drop size on the degradation rate was not found. The difference between CP and PA emulsions behavior could be due to the fact that cholesterol produced during the ester degradation has a protective effect on the sludge. PMID:14640211

  18. Anaerobic and aerobic transformation of TNT

    SciTech Connect

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

    1996-12-31

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

  19. Relevance of Routine Use of the Anaerobic Blood Culture Bottle▿

    PubMed Central

    Grohs, Patrick; Mainardi, Jean-Luc; Podglajen, Isabelle; Hanras, Xavier; Eckert, C.; Buu-Hoï, A.; Varon, E.; Gutmann, Laurent

    2007-01-01

    Using the BacT/Alert automated system, we conducted a 1-year retrospective study on blood cultures, focusing on the relevance of routine use of the anaerobic bottle. The rate of patients with positive blood cultures was 19.7%. Among these, 13.5% had a positive anaerobic bottle in the absence of any aerobic bottle, and 2/3 of these grew with nonobligate anaerobes. These patients were hospitalized in 20 out of 26 wards of the hospital group. For 65.4% of the monomicrobial-positive blood cultures growing Enterobacteriaceae, the anaerobic bottle detected growth earlier than the corresponding aerobic bottle. These data suggest that, in our institution, the use of an anaerobic bottle is still relevant. PMID:17581942

  20. Anaerobic digestion of hog wastes: Principles and practice

    SciTech Connect

    Oleszkiewicz, J.A.; Bujoczek, G.

    1996-12-31

    The principles and overview of research, development and implementation of anaerobic digestion for hog wastes are discussed. Based on economic evaluations, an anaerobic technology is cost-effective, especially for a larger herd and becomes more competitive with aerobic treatment. Nevertheless, the rate of treatment is more sensitive and dependent on the particular fraction of manure being processed. Considering the different factors affecting anaerobic digestion, a complete mixed reactor with solids recycle (having high solids retention time and low hydraulic retention time) was found to be the more reliable system with regards to methane generation and manure stabilization. By solids recycle one can obtain significant saving in the reactor volume required, while still achieving the expected degree of treatment. It was also found that even though treatment using advanced anaerobic systems when compared with simple anaerobic systems is more expensive, the rate of return on investment and efficiency of the process are higher.

  1. Determination of mercury and organomercurial resistance in obligate anaerobic bacteria.

    PubMed

    Rudrik, J T; Bawdon, R E; Guss, S P

    1985-03-01

    A methodology for determining the minimum inhibitory concentration of inorganic and organomercurial compounds for obligate anaerobic bacteria is described. A wide variation in the susceptibility of anaerobic clinical and sewage isolates was observed. Isolates of Bacteroides ruminicola and Clostridium perfringens resistant to mercury were examined for their plasmid content and ability to demonstrate inducible resistance. None of the resistant anaerobes contained any plasmids, while resistant facultative isolates from the same source contained several plasmids. In 24 h, resistant strains of clostridia and Bacteroides volatilized 20 and 43% of the 203Hg2+ added to cultures, while Escherichia coli R100 and a sewage isolate of Enterobacter cloacae volatilized 63 and 27%, respectively, of the added 203Hg2+. Attempts to induce mercury resistance in the aerobic isolates were successful, but no induction was seen in the anaerobes. Thus, mercury resistance in these anaerobic isolates was neither inducible nor plasmid mediated. PMID:4005712

  2. Adsorption and decolorization kinetics of methyl orange by anaerobic sludge.

    PubMed

    Yu, Lei; Li, Wen-Wei; Lam, Michael Hon-Wah; Yu, Han-Qing

    2011-05-01

    Adsorption and decolorization kinetics of methyl orange (MO) by anaerobic sludge in anaerobic sequencing batch reactors were investigated. The anaerobic sludge was found to have a saturated adsorption capacity of 36 ± 1 mg g MLSS(-1) to MO. UV/visible spectrophotometer and high-performance liquid chromatography analytical results indicated that the MO adsorption and decolorization occurred simultaneously in this system. This process at various substrate concentrations could be well simulated using a modified two-stage model with apparent pseudo first-order kinetics. Furthermore, a noncompetitive inhibition kinetic model was also developed to describe the MO decolorization process at high NaCl concentrations, and an inhibition constant of 3.67 g NaCl l(-1) was estimated. This study offers an insight into the adsorption and decolorization processes of azo dyes by anaerobic sludge and provides a better understanding of the anaerobic dye decolorization mechanisms. PMID:21279343

  3. A modeling approach to describe ZVI-based anaerobic system.

    PubMed

    Xiao, Xiao; Sheng, Guo-Ping; Mu, Yang; Yu, Han-Qing

    2013-10-15

    Zero-valent iron (ZVI) is increasingly being added into anaerobic reactors to enhance the biological conversion of various less biodegradable pollutants (LBPs). Our study aimed to establish a new structure model based on the Anaerobic Digestion Model No. 1 (ADM1) to simulate such a ZVI-based anaerobic reactor. Three new processes, i.e., electron release from ZVI corrosion, H2 formation from ZVI corrosion, and transformation of LBPs, were integrated into ADM1. The established model was calibrated and tested using the experimental data from one published study, and validated using the data from another work. A good relationship between the predicted and measured results indicates that the proposed model was appropriate to describe the performance of the ZVI-based anaerobic system. Our model could provide more precise strategies for the design, development, and application of anaerobic systems especially for treating various LBPs-containing wastewaters. PMID:23932771

  4. Biochemistry and Evolution of Anaerobic Energy Metabolism in Eukaryotes

    PubMed Central

    Müller, Miklós; Mentel, Marek; van Hellemond, Jaap J.; Henze, Katrin; Woehle, Christian; Gould, Sven B.; Yu, Re-Young; van der Giezen, Mark

    2012-01-01

    Summary: Major insights into the phylogenetic distribution, biochemistry, and evolutionary significance of organelles involved in ATP synthesis (energy metabolism) in eukaryotes that thrive in anaerobic environments for all or part of their life cycles have accrued in recent years. All known eukaryotic groups possess an organelle of mitochondrial origin, mapping the origin of mitochondria to the eukaryotic common ancestor, and genome sequence data are rapidly accumulating for eukaryotes that possess anaerobic mitochondria, hydrogenosomes, or mitosomes. Here we review the available biochemical data on the enzymes and pathways that eukaryotes use in anaerobic energy metabolism and summarize the metabolic end products that they generate in their anaerobic habitats, focusing on the biochemical roles that their mitochondria play in anaerobic ATP synthesis. We present metabolic maps of compartmentalized energy metabolism for 16 well-studied species. There are currently no enzymes of core anaerobic energy metabolism that are specific to any of the six eukaryotic supergroup lineages; genes present in one supergroup are also found in at least one other supergroup. The gene distribution across lineages thus reflects the presence of anaerobic energy metabolism in the eukaryote common ancestor and differential loss during the specialization of some lineages to oxic niches, just as oxphos capabilities have been differentially lost in specialization to anoxic niches and the parasitic life-style. Some facultative anaerobes have retained both aerobic and anaerobic pathways. Diversified eukaryotic lineages have retained the same enzymes of anaerobic ATP synthesis, in line with geochemical data indicating low environmental oxygen levels while eukaryotes arose and diversified. PMID:22688819

  5. Anaerobic Antimicrobial Therapy After Necrotizing Enterocolitis in VLBW Infants

    PubMed Central

    Autmizguine, Julie; Hornik, Christoph P.; Benjamin, Daniel K.; Laughon, Matthew M.; Clark, Reese H.; Cotten, C. Michael; Cohen-Wolkowiez, Michael; Benjamin, Daniel K.

    2015-01-01

    OBJECTIVE: To evaluate the effect of anaerobic antimicrobial therapy for necrotizing enterocolitis (NEC) on clinical outcomes in very low birth weight (≤1500 g) infants. METHODS: We identified very low birth weight infants with NEC from 348 US NICUs from 1997 to 2012. Anaerobic antimicrobial therapy was defined by antibiotic exposure on the first day of NEC. We matched (1:1) infants exposed to anaerobic antimicrobial therapy with infants who were not exposed by using a propensity score stratified by NEC severity (medical and surgical). The primary composite outcome was in-hospital death or intestinal stricture. We assessed the relationship between anaerobic antimicrobial therapy and outcome by using a conditional logistic regression on the matched cohort. RESULTS: A total of 1390 infants exposed to anaerobic antimicrobial therapy were matched with 1390 infants not exposed. Mean gestational age and birth weight were 27 weeks and 946 g, respectively, and were similar in both groups. We found no significant difference in the combined outcome of death or strictures, but strictures as a single outcome were more common in the anaerobic antimicrobial therapy group (odds ratio 1.73; 95% confidence interval, 1.11–2.72). Among infants with surgical NEC, mortality was less common with anaerobic antimicrobial therapy (odds ratio 0.71; 95% confidence interval, 0.52–0.95). CONCLUSIONS: Anaerobic antimicrobial therapy was not associated with the composite outcome of death or strictures but was associated with an increase in intestinal strictures. This higher incidence of intestinal strictures may be explained by the fact that death is a competing outcome for intestinal strictures, and mortality was slightly lower in the anaerobic cohort. Infants with surgical NEC who received anaerobic antimicrobial therapy had lower mortality. PMID:25511117

  6. Are incidence and epidemiology of anaerobic bacteremia really changing?

    PubMed

    Vena, A; Muñoz, P; Alcalá, L; Fernandez-Cruz, A; Sanchez, C; Valerio, M; Bouza, E

    2015-08-01

    Incidence, prognosis and need of performing blood cultures for anaerobic bacteria are under debate, mainly due to the belief that the presence of anaerobes in blood can be easily suspected on clinical basis. We aimed to assess these three points in a retrospective analysis of a 10-year experience in our tertiary hospital. All episodes of significant anaerobic bacteremia diagnosed from 2003 to 2012 were included. Risk factors for mortality and clinical predictability of anaerobic bacteremia were evaluated in 113 randomly selected episodes. Overall incidence of anaerobic bacteremia was 1.2 episodes/1000 admissions, with no significant changes during the 10-year study period. B. fragilis group (38.1 %) and Clostridium spp. (13.7 %) were the most frequent isolated microorganisms. As for the clinical study, 43.4 % of the patients had a comorbidity classified as ultimately fatal or rapidly fatal according to the McCabe and Jackson scale. Clinical manifestations suggestive of anaerobic involvement were present in only 55 % of the patients. Twenty-eight patients (24.8 %) died during the hospitalization. Independent predictive factors of mortality were a high Charlson's comorbidity index and presentation with septic shock, whereas, an adequate source control of the infection was associated with a better outcome. In our centre, incidence of anaerobic bacteremia remained stable during the last decade. The routine use of anaerobic BCs seems to be adequate, since in about half of the cases anaerobes could not be suspected on clinical bases. Moreover, prompt source control of infection is essential in order to reduce mortality of patients with anaerobic bacteremia. PMID:26017663

  7. Comparison of Aerobic and Anaerobic Biodegradation of Sugarcane Vinasse.

    PubMed

    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

  8. Bioaugmentation of overloaded anaerobic digesters restores function and archaeal community.

    PubMed

    Tale, V P; Maki, J S; Zitomer, D H

    2015-03-01

    Adding beneficial microorganisms to anaerobic digesters for improved performance (i.e. bioaugmentation) has been shown to decrease recovery time after organic overload or toxicity upset. Compared to strictly anaerobic cultures, adding aerotolerant methanogenic cultures may be more practical since they exhibit higher methanogenic activity and can be easily dried and stored in ambient air for future shipping and use. In this study, anaerobic digesters were bioaugmented with both anaerobic and aerated, methanogenic propionate enrichment cultures after a transient organic overload. Digesters bioaugmented with anaerobic and moderately aerated cultures recovered 25 and 100 days before non-bioaugmented digesters, respectively. Increased methane production due to bioaugmentation continued a long time, with 50-120% increases 6 to 12 SRTs (60-120 days) after overload. In contrast to the anaerobic enrichment, the aerated enrichments were more effective as bioaugmentation cultures, resulting in faster recovery of upset digester methane and COD removal rates. Sixty days after overload, the bioaugmented digester archaeal community was not shifted, but was restored to one similar to the pre-overload community. In contrast, non-bioaugmented digester archaeal communities before and after overload were significantly different. Organisms most similar to Methanospirillum hungatei had higher relative abundance in well-operating, undisturbed and bioaugmented digesters, whereas organisms similar to Methanolinea tarda were more abundant in upset, non-bioaugmented digesters. Bioaugmentation is a beneficial approach to increase digester recovery rate after transient organic overload events. Moderately aerated, methanogenic propionate enrichment cultures were more beneficial augments than a strictly anaerobic enrichment. PMID:25528544

  9. Degradation of natural and synthetic polyesters under anaerobic conditions.

    PubMed

    Abou-Zeid, D M; Müller, R J; Deckwer, W D

    2001-03-30

    Often, degradability under anaerobic conditions is desirable for plastics claimed to be biodegradable, e.g. in anaerobic biowaste treatment plants, landfills and in natural anaerobic sediments. The biodegradation of the natural polyesters poly(beta-hydroxybutyrate) (PHB), poly(beta-hydroxybutyrate-co-11.6%-beta-hydroxyvalerate) (PHBV) and the synthetic polyester poly(epsilon-caprolactone) (PCL) was studied in two anaerobic sludges and individual polyester degrading anaerobic strains were isolated, characterized and used for degradation experiments under controlled laboratory conditions. Incubation of PHB and PHBV films in two anaerobic sludges exhibited significant degradation in a time scale of 6-10 weeks monitored by weight loss and biogas formation. In contrast to aerobic conditions, PHB was degraded anaerobically more rapidly than the copolyester PHBV, when tested with either mixed cultures or a single strained isolate. PCL tends to degrade slower than the natural polyesters PHB and PHBV. Four PHB and PCL degrading isolates were taxonomically identified and are obviously new species belonging to the genus Clostridium group I. The depolymerizing enzyme systems of PHB and PCL degrading isolates are supposed to be different. Using one isolated strain in an optimized laboratory degradation test with PHB powder, the degradation time was drastically reduced compared to the degradation in sludges (2 days vs. 6-10 weeks). PMID:11245900

  10. Trace metal speciation and bioavailability in anaerobic digestion: A review.

    PubMed

    Thanh, Pham Minh; Ketheesan, Balachandran; Yan, Zhou; Stuckey, David

    2016-01-01

    Trace metals are essential for the growth of anaerobic microorganisms, however, in practice they are often added to anaerobic digesters in excessive amounts, which can lead to inhibition. The concept of bioavailability of metals in anaerobic digestion has been poorly understood in the past, and a lack of deep understanding of the relationship between trace metal speciation and bioavailability can result in ineffective metal dosing strategies for anaerobic digesters. Sequential extraction schemes are useful for fractionating trace metals into their different forms, and metal sulfides can serve as a store and source for trace metals during anaerobic digestion, while natural/synthetic chelating agents (soluble microbial products-SMPs, extracellular polysaccharides-EPS, and EDTA/NTA) are capable of controlling trace metal bioavailability. Nevertheless, more work is needed to: investigate the speciation and bioavailability of Ca, Mg, Mn, W, and Se; compare the bioavailability of different forms of trace metals e.g. carbonates, sulfides, phosphates to different anaerobic trophic groups; determine what factors influence metal sulfide dissolution; investigate whether chelating agents can increase trace metal bioavailability; develop and adapt specialized analytical techniques, and; determine how trace metal dynamics change in an anaerobic membrane bioreactor (AnMBR). PMID:26707985

  11. Dispersal of non-sporeforming anaerobic bacteria from the skin.

    PubMed Central

    Benediktsdóttir, E.; Hambraeus, A.

    1982-01-01

    Dispersal of non-sporeforming anaerobic bacteria was studied. Skin samples were taken from the subjects, and dispersed from different parts of the body was examined. The number of anaerobic bacteria dispersed was not correlated to their density on the surface of skin area exposed. The highest density of anaerobic bacteria on the skin was found in the face and upper trunk, but the highest yield of anaerobic bacteria dispersed came from the lower trunk. The dominant anaerobic bacteria dispersed were Propionibacterium acnes, but Propionibacterium avidum, Propionibacterium granulosum and Gram-positive cocci were also isolated from the dispersal samples. Peptococcus magnus was the most common coccus isolated. For the less frequently isolated bacteria, the best correlation was found between the perineal flora and airborne bacteria. A comparison was also made of bacterial dispersal by naked and dressed subjects. The dispersal of both aerobic and anaerobic bacteria was higher when the subjects were dressed in conventional operating theatre cotton clothing than when they were naked. The increased dispersal of anaerobic bacteria when the subjects were dressed was mainly due to increased dispersal of Propionibacterium sp. PMID:6806353

  12. Calorimetric studies of the growth of anaerobic microbes.

    PubMed

    Miyake, Hideo; Maeda, Yukiko; Ishikawa, Takashi; Tanaka, Akiyoshi

    2016-09-01

    This article aims to validate the use of calorimetry to measure the growth of anaerobic microbes. It has been difficult to monitor the growth of strict anaerobes while maintaining optimal growth conditions. Traditionally, optical density and ATP concentration are usually used as measures of the growth of anaerobic microbes. However, to take these measurements it is necessary to extract an aliquot of the culture, which can be difficult while maintaining anaerobic conditions. In this study, calorimetry was used to continuously and nondestructively measure the heat generated by the growth of anaerobic microbes as a function of time. Clostridium acetobutylicum, Clostridium beijerinckii, and Clostridium cellulovorans were used as representative anaerobic microbes. Using a multiplex isothermal calorimeter, we observed that peak time (tp) of C. acetobutylicum heat evolution increased as the inoculation rate decreased. This strong correlation between the inoculation rate and tp showed that it was possible to measure the growth rate of anaerobic microbes by calorimetry. Overall, our results showed that there is a very good correlation between heat evolution and optical density/ATP concentration, validating the use of the method. PMID:27012376

  13. Anaerobic Treatment of Palm Oil Mill Effluent in Pilot-Scale Anaerobic EGSB Reactor

    PubMed Central

    Wang, Jin; Mahmood, Qaisar; Qiu, Jiang-Ping; Li, Yin-Sheng; Chang, Yoon-Seong; Li, Xu-Dong

    2015-01-01

    Large volumes of untreated palm oil mill effluent (POME) pose threat to aquatic environment due to the presence of very high organic content. The present investigation involved two pilot-scale anaerobic expanded granular sludge bed (EGSB) reactors, continuously operated for 1 year to treat POME. Setting HRT at 9.8 d, the anaerobic EGSB reactors reduced COD from 71179 mg/L to 12341 mg/L and recycled half of sludge by a dissolved air flotation (DAF). The average effluent COD was 3587 mg/L with the consistent COD removal efficiency of 94.89%. Adding cationic polymer (PAM) dose of 30 mg/L to DAF unit and recycling its half of sludge caused granulation of anaerobic sludge. Bacilli and small coccid bacteria were the dominant microbial species of the reactor. The reactor produced 27.65 m3 of biogas per m3 of POME which was utilized for electricity generation. PMID:26167485

  14. PCB dechlorination in anaerobic soil slurry reactors

    SciTech Connect

    Klasson, K.T.; Evans, B.S.

    1993-11-29

    Many industrial locations, including the US Department of Energy`s, have identified needs for treatment of polychlorinated biphenyl (PCB) wastes and remediation of PCB-contaminated sites. Biodegradation of PCBs is a potentially effective technology for the treatment of PCB-contaminated soils and sludges, including mixed wastes; however, a practical remediation technology has not yet been demonstrated. In laboratory experiments, soil slurry bioreactors inoculated with microorganisms extracted from PCB-contaminated sediments from the Hudson River have been used to obtain anaerobic dechlorination of PCBS. The onset of dechlorination activity can be accelerated by addition of nutritional amendments and inducers. After 15 weeks of incubation with PCB-contaminated soil and nutrient solution, dechlorination has been observed under several working conditions. The best results show that the average chlorine content steadily dropped from 4.3 to 3.5 chlorines per biphenyl over a 15-week period.

  15. [Antimicrobial susceptibility testing of anaerobic bacteria].

    PubMed

    García-Sánchez, José E; García-Sánchez, Enrique; García-García, María Inmaculada

    2014-02-01

    The anaerobic bacteria resistance to antibiotics is increasing, and even has appeared against the most active of those, like metronidazol and carbapenems. This fact forces to make and periodical sensibility tests -at least in the most aggressive and virulent species, in cases that they are isolated from life locations and in the absence of therapeutic response- to check the local sensibility and to establish suitable empiric therapies, all based on multicentric studies carried out in order to this or well to check the activity of new antibiotics. For the laboratory routine, the easiest sensibility method is the E-test/MIC evaluator. Another alternative is microdilution, that's only normalized for Bacteroides. There are preliminary facts that allow the use of disc diffusion method in some species of Bacteroides and Clostridium. For the temporal and multicentric studies, the procedure is dilution in agar plate, the reference method. PMID:24630580

  16. Photoenhanced anaerobic digestion of organic acids

    DOEpatents

    Weaver, Paul F.

    1990-01-01

    A process is described for rapid conversion of organic acids and alcohols anaerobic digesters into hydrogen and carbon dioxide, the optimal precursor substrates for production of methane. The process includes addition of photosynthetic bacteria to the digester and exposure of the bacteria to radiant energy (e.g., solar energy). The process also increases the pH stability of the digester to prevent failure of the digester. Preferred substrates for photosynthetic bacteria are the organic acid and alcohol waste products of fermentative bacteria. In mixed culture with methanogenic bacteria or in defined co-culture with non-aceticlastic methanogenic bacteria, photosynthetic bacteria are capable of facilitating the conversion or organic acids and alcohols into methane with low levels of light energy input.

  17. Anaerobic dechlorination and the bioremediation of PCBs

    SciTech Connect

    Quensen, J.F. III; Boyd, S.A.; Tiedje, J.M. )

    1990-01-01

    The recently discovered process of biologically mediated reductive dechlorination of PCBs promises to overcome some of the limitations of aerobic PCB biodegradation. This process, first suspected from the altered chromatographic pattern observed for Hudson River sediment samples, has been duplicated in the laboratory. The process removes meta and para chlorines, resulting in a PCB mixture that is both less toxic and more aerobically degradable. It is active at higher PCB concentrations (at least 5,000 ppm), and does not require induction by biphenyl or a monochlorinated biphenyl. The literature on the aerobic biodegradation of PCBs is briefly reviewed for the purpose of pointing out the limitations of aerobic PCB degradation that an anaerobic pretreatment can be expected to overcome, and the results of our own research on the reductive dechlorination of PCBs is summarized.

  18. Kinetics of biogas production in Anaerobic Filters.

    PubMed

    Krümpel, Johannes; Schäufele, Friedrich; Schneider, Johannes; Jungbluth, Thomas; Zielonka, Simon; Lemmer, Andreas

    2016-01-01

    This study investigates methane production kinetics from individual volatile fatty acids (VFA) in an Upflow Anaerobic Filter (AF). 1gCOD in the form of acetic (HAc), propionic (HPr) or butyric acid (HBu) was injected into the AF while operating at an organic loading rate (OLRCOD) of 3.5gL(-1)d(-1). A new method is introduced to separate gas production of the baseload from the product formation of VFA degradation after the injection. The lag phase, fractional rate of gas production and half-life has been determined for the methane production of the three VFAs. The half-lives were in the order HAc

  19. CFD simulation of mixing in anaerobic digesters.

    PubMed

    Terashima, Mitsuharu; Goel, Rajeev; Komatsu, Kazuya; Yasui, Hidenari; Takahashi, Hiroshi; Li, Y Y; Noike, Tatsuya

    2009-04-01

    A three-dimensional CFD model incorporating the rheological properties of sludge was developed and applied to quantify mixing in a full-scale anaerobic digester. The results of the model were found to be in good agreement with experimental tracer response curve. In order to predict the dynamics of mixing, a new parameter, UI (uniformity index) was defined. The visual patterns of tracer mixing in simulation were well reflected in the dynamic variation in the value of UI. The developed model and methods were applied to determine the required time for complete mixing in a full-scale digester at different solid concentrations. This information on mixing time is considered to be useful in optimizing the feeding cycles for better digester performance. PMID:19081247

  20. Anaerobic biodegradation of cyanide under methanogenic conditions.

    PubMed Central

    Fallon, R D; Cooper, D A; Speece, R; Henson, M

    1991-01-01

    Upflow, anaerobic, fixed-bed, activated charcoal biotreatment columns capable of operating at free cyanide concentrations of greater than 100 mg liter-1 with a hydraulic retention time of less than 48 h were developed. Methanogenesis was maintained under a variety of feed medium conditions which included ethanol, phenol, or methanol as the primary reduced carbon source. Under optimal conditions, greater than 70% of the inflow free cyanide was removed in the first 30% of the column height. Strongly complexed cyanides were resistant to removal. Ammonia was the nitrogen end product of cyanide transformation. In cell material removed from the charcoal columns, [14C]bicarbonate was the major carbon end product of [14C]cyanide transformation. PMID:1872600

  1. Degradation of methyl bromide in anaerobic sediments

    USGS Publications Warehouse

    Oremland, R.S.; Miller, L.G.; Strohmaler, F.E.

    1994-01-01

    Methyl bromide (MeBr) was anaerobically degraded in saltmarsh sediments after reaction with sulfide. The product of this nucleophilic substitution reaction was methanethiol, which underwent further chemical and bacterial reactions to form dimethyl sulfide. These two gases appeared transiently during sediment incubations because they were metabolized by methanogenic and sulfate-reducing bacteria. A second, less significant reaction of MeBr was the exchange with chloride, forming methyl chloride, which was also susceptible to attack by sulfide. Incubation of 14C-labeled methyl iodide as an analogue of MeBr resulted in the formation of 14CH4 and 14CO2 and also indicated that sulfate-reducing bacteria as well as methanogens metabolized the methylated sulfur intermediates. These results suggest that exposed sediments with abundant free sulfide, such as coastal salt-marshes, may constitute a sink for atmospheric MeBr.

  2. Anaerobic polymers as high vacuum leak sealants

    NASA Technical Reports Server (NTRS)

    Kendall, B. R. F.

    1982-01-01

    Anaerobic polymers are useful as solventless leak sealants with good vacuum properties at moderate temperatures. Loctite 290 can seal leaks in a range generally encountered in carefully constructed ultrahigh vacuum and high vacuum systems. It was found that small leaks are sealed best under vacuum, whereas large leaks should be sealed at atmospheric pressure. The high-temperature behavior of Loctite 290 is limited by its fast cure, which prevents deep penetration into small leaks; cracking eventually occurs at the entrance to the leak. Repeated thermal cycling to about 300 C is possible, however, provided viscosity, curing time, and leak size are properly matched to ensure penetration into the body of the leak. This may require special formulations for high temperature vacuum applications.

  3. Determining anaerobic degradation kinetics from batch tests.

    PubMed

    Moreda, Iván López

    2016-01-01

    Data obtained from a biomethane potential (BMP) test were used in order to obtain the parameters of a kinetic model of solid wastes anaerobic degradation. The proposed model considers a hydrolysis step with a first order kinetic, a Monod kinetic for the soluble organic substrate degradation and a first order decay of microorganisms. The instantaneous release of methane was assumed. The parameters of the model are determined following a direct search optimization procedure. A 'multiple-shooting' technique was used as a first step of the optimization process. The confidence interval of the parameters was determined by using Monte Carlo simulations. Also, the distribution functions of the parameters were determined. Only the hydrolysis first order constant shows a normal distribution. PMID:27191569

  4. Anaerobic bacteraemia: a 10-year retrospective epidemiological survey.

    PubMed

    De Keukeleire, Steven; Wybo, Ingrid; Naessens, Anne; Echahidi, Fedoua; Van der Beken, Mieke; Vandoorslaer, Kristof; Vermeulen, Stefan; Piérard, Denis

    2016-06-01

    In order to identify current trends in anaerobic bacteraemia, a 10-year retrospective study was performed in the University Hospital Brussel, Belgium. All clinically relevant bacteraemia detected from 2004 until 2013 were included. Medical records were reviewed in an attempt to define clinical parameters that might be associated with the occurrence of anaerobic bacteraemia. 437 of the isolated organisms causing anaerobic bacteraemia were thawed, subcultured and reanalyzed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF). There were an average of 33 cases of anaerobic bacteraemia per year during 2004-2008 compared to an average of 27 cases per year during 2009-2013 (P = 0.017), corresponding to a decrease by 19% between the first and the latter period. Also, the total number of cases of anaerobic bacteraemia per 100,000 patient days decreased from 17.3 in the period from 2004 to 2008 to 13.7 in the period 2009 to 2013 (P = 0.023). Additionally, the mean incidence of anaerobic bacteraemia decreased during the study period (1.27/1000 patients in 2004 vs. 0.94/1000 patients in 2013; P = 0.008). In contrast, the proportion of isolated anaerobic bacteraemia compared to the number of all bacteraemia remained stable at 5%. Bacteroides spp. and Parabacteroides spp. accounted for 47.1% of the anaerobes, followed by 14.4% Clostridium spp., 12.6% non-spore-forming Gram-positive rods, 10.5% anaerobic cocci, 8.2% Prevotella spp. and other Gram-negative rods and 7.1% Fusobacterium spp. The lower gastrointestinal tract (47%) and wound infections (10%) were the two most frequent sources for bacteraemia, with the origin remaining unknown in 62 cases (21%). The overall mortality rate was 14%. Further studies focusing on the antimicrobial susceptibility and demographic background of patients are needed to further objectify the currently observed trends. PMID:26923749

  5. Ureolytic phosphate precipitation from anaerobic effluents.

    PubMed

    Desmidt, E; Verstraete, W; Dick, J; Meesschaert, B D; Carballa, M

    2009-01-01

    In this work, the elimination of phosphate from industrial anaerobic effluents was evaluated at lab-scale. For that purpose, the ureolytic method previously developed for the precipitation of Ca(2 + ) from wastewater as calcite was adapted for the precipitation of phosphate as struvite. In the first part of the study, computer simulations using MAPLE and PHREEQC were performed to model phosphate precipitation from wastewater as struvite. The results obtained showed that relative high concentrations of ammonium and magnesium are needed to precipitate phosphate as struvite. The total molar concentrations ratio of Mg(2 + ):PO(4) (3-)-P:NH(4) (+) required to decrease PO(4) (3-)-P concentrations from 20 to 6 mg PO(4) (3-)-P/l at pH 8.4-8.5 was estimated on 4.6:1:8. In the second part of the study, lab-scale experiments with either synthetic wastewater or the anaerobic effluent from a vegetable processing industry were carried out in batch and continuous mode. Overall, the continuous operation at a hydraulic retention time (HRT) of 2.4 h and an added molar concentration [Mg(2 + )]:[PO(4) (3-)-P]:[NH(4) (+)] ratio of 1.6:1:2.3 resulted in a constant pH value in the reactor (around 8.5) and an efficient phosphate removal (>90%) to residual levels of 1-2 mg PO(4) (3-)-P/l. Different operational conditions, such as the initial phosphate concentration, HRT and the use of CaCl(2) or MgO instead of MgCl(2), were analysed and the performance of the reactor was satisfactory under a broad range of them. Yet, overall, optimal results (higher phosphate removal) were obtained with MgCl(2). PMID:19474493

  6. Anaerobic toxicity of cationic silver nanoparticles.

    PubMed

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

    2016-07-01

    The microbial toxicity of silver nanoparticles (AgNPs) stabilized with different capping agents was compared to that of Ag(+) under anaerobic conditions. Three AgNPs were investigated: (1) negatively charged citrate-coated AgNPs (citrate-AgNPs), (2) minimally charged polyvinylpyrrolidone coated AgNPs (PVP-AgNPs) and (3) positively charged branched polyethyleneimine coated AgNPs (BPEI-AgNPs). The AgNPs investigated in this experiment were similar in size (10-15nm), spherical in shape, but varied in surface charge which ranged from highly negative to highly positive. While, at AgNPs concentrations lower than 5mgL(-1), the anaerobic decomposition process was not influenced by the presence of the nanoparticles, there was an observed impact on the diversity of the microbial community. At elevated concentrations (100mgL(-1) as silver), only the cationic BPEI-AgNPs demonstrated toxicity similar in magnitude to that of Ag(+). Both citrate and PVP-AgNPs did not exhibit toxicity at the 100mgL(-1) as measured by biogas evolution. These findings further indicate the varying modes of action for nanoparticle toxicity and represent one of the few studies that evaluate end-of-life management concerns with regards to the increasing use of nanomaterials in our everyday life. These findings also highlight some of the concerns with a one size fits all approach to the evaluation of environmental health and safety concerns associated with the use of nanoparticles. PMID:27016684

  7. Clostridium difficile: the anaerobe that made the grade.

    PubMed

    Brazier, Jon S

    2012-04-01

    Unlike other anaerobic bacteria of clinical importance, Clostridium difficile has managed to enter into the realm of public awareness. Following the trail blazed by methicillin-resistant Staphylococcus aureus (MRSA), C. difficile has made the transition from being an obscure anaerobic bacterium, mainly of interest to specialist anaerobic microbiologists, to that of an infamous "superbug" responsible for outbreaks of hospital-acquired infection that commonly result in serious disease and death. This report picks out key moments, particularly in the UK, which tracked the rise in both the public and political awareness of this organism. PMID:22293217

  8. Neural fuzzy modeling of anaerobic biological wastewater treatment systems

    SciTech Connect

    Tay, J.H.; Zhang, X.

    1999-12-01

    Anaerobic biological wastewater treatment systems are difficult to model because their performance is complex and varies significantly with different reactor configurations, influent characteristics, and operational conditions. Instead of conventional kinetic modeling, advanced neural fuzzy technology was employed to develop a conceptual adaptive model for anaerobic treatment systems. The conceptual neural fuzzy model contains the robustness of fuzzy systems, the learning ability of neural networks, and can adapt to various situations. The conceptual model was used to simulate the daily performance of two high-rate anaerobic wastewater treatment systems with satisfactory results obtained.

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

    PubMed Central

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

    2015-01-01

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

  10. [Achievement of Sulfate-Reducing Anaerobic Ammonium Oxidation Reactor Started with Nitrate-Reducting Anaerobic Ammonium Oxidation].

    PubMed

    Liu, Zheng-chuan; Yuan, Lin-jiang; Zhou, Guo-biao; Li, Jing

    2015-09-01

    The transformation of nitrite-reducing anaerobic ammonium oxidation to sulfate-reducing anaerobic ammonium oxidation in an UASB was performed and the changes in microbial community were studied. The result showed that the sulfate reducing anaerobic ammonium oxidation process was successfully accomplished after 177 days' operation. The removal rate of ammonium nitrogen and sulfate were up to 58. 9% and 15. 7%, the removing load of ammonium nitrogen and sulfate were 74. 3 mg.(L.d)-1 and 77. 5 mg.(L.d)-1 while concentration of ammonium nitrogen and sulfate of influent were 130 mg.(L.d)-1 and 500 mg.(L.d)-1, respectively. The lost nitrogen and sulphur was around 2 in molar ratio. The pH value of the effluent was lower than that of the influent. Instead of Candidatus brocadia in nitrite reducing anaerobic ammonium oxidation granular sludge, Bacillus benzoevorans became the dominant species in sulfate reducing anaerobic ammonium oxidation sludge. The dominant bacterium in the two kinds of anaerobic ammonium oxidation process is different. Our results imply that the two anaerobic ammonium oxidation processes are carried out by different kind of bacterium. PMID:26717697

  11. Microbial and Physicochemical Characteristics of Compact Anaerobic Ammonium-Oxidizing Granules in an Upflow Anaerobic Sludge Blanket Reactor ▿

    PubMed Central

    Ni, Bing-Jie; Hu, Bao-Lan; Fang, Fang; Xie, Wen-Ming; Kartal, Boran; Liu, Xian-Wei; Sheng, Guo-Ping; Jetten, Mike; Zheng, Ping; Yu, Han-Qing

    2010-01-01

    Anaerobic ammonium oxidation (anammox) is a promising new process to treat high-strength nitrogenous wastewater. Due to the low growth rate of anaerobic ammonium-oxidizing bacteria, efficient biomass retention is essential for reactor operation. Therefore, we studied the settling ability and community composition of the anaerobic ammonium-oxidizing granules, which were cultivated in an upflow anaerobic sludge blanket (UASB) reactor seeded with aerobic granules. With this seed, the start-up period was less than 160 days at a NH4+-N removal efficiency of 94% and a loading rate of 0.064 kg N per kg volatile suspended solids per day. The formed granules were bright red and had a high settling velocity (41 to 79 m h−1). Cells and extracellular polymeric substances were evenly distributed over the anaerobic ammonium-oxidizing granules. The high percentage of anaerobic ammonium-oxidizing bacteria in the granules could be visualized by fluorescent in situ hybridization and electron microscopy. The copy numbers of 16S rRNA genes of anaerobic ammonium-oxidizing bacteria in the granules were determined to be 4.6 × 108 copies ml−1. The results of this study could be used for a better design, shorter start-up time, and more stable operation of anammox systems for the treatment of nitrogen-rich wastewaters. PMID:20190088

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

    PubMed Central

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

    2016-01-01

    Wastewater from an anaerobic treatment plant at a slaughterhouse was analysed to determine the bacterial biodiversity present. Molecular analysis of the anaerobic sludge obtained from the treatment plant showed significant diversity, as 27 different phyla were identified. Firmicutes, Proteobacteria, Bacteroidetes, Thermotogae, Euryarchaeota (methanogens), and msbl6 (candidate division) were the dominant phyla of the anaerobic treatment plant and represented 21.7%, 18.5%, 11.5%, 9.4%, 8.9%, and 8.8% of the total bacteria identified, respectively. The dominant bacteria isolated were Clostridium, Bacteroides, Desulfobulbus, Desulfomicrobium, Desulfovibrio and Desulfotomaculum. Our results revealed the presence of new species, genera and families of microorganisms. The most interesting strains were characterised. Three new bacteria involved in anaerobic digestion of abattoir wastewater were published. PMID:26887229

  13. Nitrification and denitrification gene abundances in swine wastewater anaerobic lagoons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although anaerobic lagoons are used globally for livestock waste treatment, their detailed microbial cycling of nitrogen is only beginning to become understood. Within this cycling, nitrification can be performed by organisms which produce the enzyme ammonia monooxygenase (AMO). For denitrification,...

  14. Culturing and Maintaining Clostridium difficile in an Anaerobic Environment

    PubMed Central

    Edwards, Adrianne N.; Suárez, Jose M.; McBride, Shonna M.

    2013-01-01

    Clostridium difficile is a Gram-positive, anaerobic, sporogenic bacterium that is primarily responsible for antibiotic associated diarrhea (AAD) and is a significant nosocomial pathogen. C. difficile is notoriously difficult to isolate and cultivate and is extremely sensitive to even low levels of oxygen in the environment. Here, methods for isolating C. difficile from fecal samples and subsequently culturing C. difficile for preparation of glycerol stocks for long-term storage are presented. Techniques for preparing and enumerating spore stocks in the laboratory for a variety of downstream applications including microscopy and animal studies are also described. These techniques necessitate an anaerobic chamber, which maintains a consistent anaerobic environment to ensure proper conditions for optimal C. difficile growth. We provide protocols for transferring materials in and out of the chamber without causing significant oxygen contamination along with suggestions for regular maintenance required to sustain the appropriate anaerobic environment for efficient and consistent C. difficile cultivation. PMID:24084491

  15. Characteristics, Process Parameters, and Inner Components of Anaerobic Bioreactors

    PubMed Central

    Abdelgadir, Awad; Chen, Xiaoguang; Liu, Jianshe; Xie, Xuehui; Zhang, Jian; Zhang, Kai; Wang, Heng; Liu, Na

    2014-01-01

    The anaerobic bioreactor applies the principles of biotechnology and microbiology, and nowadays it has been used widely in the wastewater treatment plants due to their high efficiency, low energy use, and green energy generation. Advantages and disadvantages of anaerobic process were shown, and three main characteristics of anaerobic bioreactor (AB), namely, inhomogeneous system, time instability, and space instability were also discussed in this work. For high efficiency of wastewater treatment, the process parameters of anaerobic digestion, such as temperature, pH, Hydraulic retention time (HRT), Organic Loading Rate (OLR), and sludge retention time (SRT) were introduced to take into account the optimum conditions for living, growth, and multiplication of bacteria. The inner components, which can improve SRT, and even enhance mass transfer, were also explained and have been divided into transverse inner components, longitudinal inner components, and biofilm-packing material. At last, the newly developed special inner components were discussed and found more efficient and productive. PMID:24672798

  16. Energy transduction by anaerobic ferric iron respiration in Thiobacillus ferrooxidans

    SciTech Connect

    Pronk, J.T.; Liem, K.; Bos, P.; Kuenen, J.G. )

    1991-07-01

    Formate-grown cells of the obligately chemolithoautotrophic acidophile Thiobacillus ferrooxidans were capable of formate- and elemental sulfur-dependent reduction of ferric iron under anaerovic conditions. Under aerobic conditions, both oxygen and ferric iron could be simultaneously used as electron acceptors. To investigate whether anaerobic ferric iron respiration by T. ferrooxidans is an energy-transducing process, uptake of amino acids was studied. Glycine uptake by starved cells did not occur in the absence of an electron donor, neither under aerobic conditions nor under anaerobic conditions. Uptake of glycine could be driven by formate- and ferrous iron-dependent oxygen uptake. Under anaerobic conditions, ferric iron respiration with the electron donors formate and elemental sulfur could energize glycine uptake. Glycine uptake was inhibited by the uncoupler 2,4-dinitrophenol. The results indicate that anaerobic ferric iron respiration can contribute to the energy budget of T. ferrooxidans.

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

    PubMed

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

    2016-01-01

    Wastewater from an anaerobic treatment plant at a slaughterhouse was analysed to determine the bacterial biodiversity present. Molecular analysis of the anaerobic sludge obtained from the treatment plant showed significant diversity, as 27 different phyla were identified. Firmicutes, Proteobacteria, Bacteroidetes, Thermotogae, Euryarchaeota (methanogens), and msbl6 (candidate division) were the dominant phyla of the anaerobic treatment plant and represented 21.7%, 18.5%, 11.5%, 9.4%, 8.9%, and 8.8% of the total bacteria identified, respectively. The dominant bacteria isolated were Clostridium, Bacteroides, Desulfobulbus, Desulfomicrobium, Desulfovibrio and Desulfotomaculum. Our results revealed the presence of new species, genera and families of microorganisms. The most interesting strains were characterised. Three new bacteria involved in anaerobic digestion of abattoir wastewater were published. PMID:26887229

  18. Biodegradability of activated sludge organics under anaerobic conditions.

    PubMed

    Ekama, G A; Sötemann, S W; Wentzel, M C

    2007-01-01

    From an experimental and theoretical investigation of the continuity of activated sludge organic (COD) compounds along the link between the fully aerobic or N removal activated sludge and anaerobic digestion unit operations, it was found that the unbiodegradable particulate organics (i) originating from the influent wastewater and (ii) generated by the activated sludge endogenous process, as determined from response of the activated sludge system, are also unbiodegradable under anaerobic digestion conditions. This means that the activated sludge biodegradable organics that can be anaerobically digested can be calculated from the active fraction of the waste activated sludge based on the widely accepted ordinary heterotrophic organism (OHO) endogenous respiration/death regeneration rates and unbiodegradable fraction. This research shows that the mass balances based steady state and dynamic simulation activated sludge, aerobic digestion and anaerobic digestion models provide internally consistent and externally compatible elements that can be coupled to produce plant wide steady state and dynamic simulation WWTP models. PMID:17045327

  19. Investigation of Anaerobic Herbicide Degradation in Agricultural Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic microbial pesticide degradation has received little attention, particularly in agricultural soils that receive routine inputs of halogenated herbicides. Seasonal rainfall in many regions can produce zones of periodic anaerobiosis in soil. Redox gradients within soil aggregates can also for...

  20. THIAMINE AND NICOTINIC ACID: ANAEROBIC GROWTH FACTORS FOR MUCOR ROUXII

    PubMed Central

    Bartnicki-Garcia, S.; Nickerson, Walter J.

    1961-01-01

    Bartnicki-Garcia, S. (Rutgers, the State University, New Brunswick, N. J.), and Walter J. Nickerson. Thiamine and nicotinic acid: Anaerobic growth factors for Mucor rouxii. J. Bacteriol. 82:142–148. 1961.—Mucor rouxii requires preformed thiamine and nicotinic acid for anaerobic growth. Such requirements are not manifested during aerobic incubation. Aerobically, the fungus was shown to be able to synthesize both vitamins. The yeastlike form and the filamentous form of anaerobically grown M. rouxii exhibit the same vitamin requirements. Thiamine can be substituted by its thiazole moiety. Under certain conditions, nicotinic acid was partly substituted by tryptophan, kynurenine, 3-hydroxykynurenine, and 3-hydroxyanthranilic acid. Anaerobically. the fungus (thiamine requiring) was about ten times more susceptible to pyrithiamine antagonism than the same organism grown aerobically (thiamine independent). PMID:16561911

  1. POLISHING THE EFFLUENT FROM AN ANAEROBIC BIOLOGICAL PERCHLORATE TREATMENT PROCESS

    EPA Science Inventory

    Anaerobic biological processes effectively reduce perchlorate to chloride. However, the effluent can be biologically unstable, high in particulates and high in disinfection by-product precursor compounds. Such an effluent would be unsuitable for transmission into a drinking water...

  2. Characteristics, process parameters, and inner components of anaerobic bioreactors.

    PubMed

    Abdelgadir, Awad; Chen, Xiaoguang; Liu, Jianshe; Xie, Xuehui; Zhang, Jian; Zhang, Kai; Wang, Heng; Liu, Na

    2014-01-01

    The anaerobic bioreactor applies the principles of biotechnology and microbiology, and nowadays it has been used widely in the wastewater treatment plants due to their high efficiency, low energy use, and green energy generation. Advantages and disadvantages of anaerobic process were shown, and three main characteristics of anaerobic bioreactor (AB), namely, inhomogeneous system, time instability, and space instability were also discussed in this work. For high efficiency of wastewater treatment, the process parameters of anaerobic digestion, such as temperature, pH, Hydraulic retention time (HRT), Organic Loading Rate (OLR), and sludge retention time (SRT) were introduced to take into account the optimum conditions for living, growth, and multiplication of bacteria. The inner components, which can improve SRT, and even enhance mass transfer, were also explained and have been divided into transverse inner components, longitudinal inner components, and biofilm-packing material. At last, the newly developed special inner components were discussed and found more efficient and productive. PMID:24672798

  3. Comparison of microbial activity in anaerobic and microaerobic digesters.

    PubMed

    Jenicek, P; Celis, C A; Koubova, J; Pokorna, D

    2011-01-01

    Microaerobic alternative of anaerobic digestion offers many advantages especially when sulfide concentration in the digester is high. For better understanding of the microaerobic technology more detailed characterization of biomass activity is needed. Two equal digesters were operated under the same condition except of microaeration in one of them. During long term operation of anaerobic and microaerobic digesters the sludge quality and the biomass activity was monitored. The activity of sulfide oxidizing bacteria of microaerobic biomass was significantly higher in comparison with anaerobic biomass. The activity of sulfate reducing bacteria was comparable. The activity of methanogenic bacteria activity depended on sulfide concentration more than on microaeration. The extent of foaming problems was lower in the microaerobic than in the anaerobic digester. PMID:21977645

  4. Anaerobic digestion as a waste disposal option for American Samoa

    SciTech Connect

    Rivard, C

    1993-01-01

    Tuna sludge and municipal solid waste (MSW) generated on Tutuila Island, American Samoa, represent an ongoing disposal problem as well as an emerging opportunity for use in renewable fuel production. This research project focuses on the biological conversion of the organic fraction of these wastes to useful products including methane and fertilizer-grade residue through anaerobic high solids digestion. In this preliminary study, the anaerobic bioconversion of tuna sludge with MSW appears promising.

  5. ANAEROBIC SOIL DISINFESTATION IN MICROCOSMS OF TWO SANDY SOILS.

    PubMed

    Stremińska, M A; Runia, W T; Termorshuizen, A J; Feil, H; Van Der Wurff, A W G

    2014-01-01

    In recent years, anaerobic soil disinfestation (ASD) has been proposed as an alternative control method of soil-borne plant pathogens. It involves adding a labile carbon source, irrigating the soil to stimulate decomposition of organic material and then covering the soil with air-tight plastic to limit gas exchange. During the ASD process, soil microorganisms switch from aerobic to anaerobic metabolism. As a result, by-products of anaerobic metabolism are released into the soil environment such as various organic acids and gases. These by-products are reported to have a negative effect on survival of soil-borne plant pathogens. However, the efficacy of ASD to reduce soil-borne pathogens in practice may vary significantly. Therefore, we studied the efficacy of the ASD process in two different soils. In addition, it was investigated whether a pre-treatment with an anaerobic bacterial inoculum prior to ASD affected the efficacy of the process. Two sandy soils (dune sand and glacial sand) were inoculated in 2 L soil microcosms. We tested the efficacy of ASD treatment against the potato cyst nematode Globodera pallida. For each soil, three treatments were used: control treatment (no Herbie addition, aerobic incubation), ASD 1 (organic substrate addition, anaerobic incubation) and ASD 2 (organic substrate and anaerobic bacterial inoculum addition, anaerobic incubation). Soil microcosms were incubated in the dark at 20°C for two weeks. We observed that anaerobic soil disinfestation treatments were highly effective against Potato Cyst Nematode (PCN), with pathogen being eradicated totally in all but one ASD treatment (glacial sand ASD2) within two weeks. The relative abundance of Firmicutes (spore-forming bacteria, often fermentative) in total bacteria increased significantly in ASD treated soils. Numbers of these bacteria correlated positively with increased concentrations of acetic and butyric acids in soil water phase in ASD treatments. PMID:26084078

  6. Validity and reliability of the Hawaii anaerobic run test.

    PubMed

    Kimura, Iris F; Stickley, Christopher D; Lentz, Melissa A; Wages, Jennifer J; Yanagi, Kazuhiko; Hetzler, Ronald K

    2014-05-01

    This study examined the reliability and validity of the Hawaii anaerobic run test (HART) by comparing anaerobic capacity measures obtained to those during the Wingate Anaerobic Test (WAnT). Ninety-six healthy physically active volunteers (age, 22.0 ± 2.8 years; height, 163.9 ± 9.5 cm; body mass, 70.6 ± 14.7 kg; body fat %, 19.29 ± 5.39%) participated in this study. Each participant performed 2 anaerobic capacity tests: the WAnT and the HART by random assignment on separate days. The reliability of the HART was calculated from 2 separate trials of the test and then determined through intraclass correlation coefficients (ICCs). Blood samples were collected, and lactate was analyzed both pretest and posttest for each of the 2 exercise modes. Heart rate and rate of perceived exertion were also measured pre- and post-exercise. Hawaii anaerobic run test peak and mean momentum were calculated as body mass times highest or average split velocity, respectively. Intraclass correlation coefficients between trials of the HART for peak and mean momentum were 0.98 and 0.99, respectively (SEM = 18.8 and 25.7, respectively). Validity of the HART was established through comparison of momentum on the HART with power on the WAnT. High correlations were found between peak power and peak momentum (r = 0.88), as well as mean power and mean momentum (r = 0.94). The HART was considered to be a reliable test of anaerobic power. The HART was also determined to be a valid test of anaerobic power when compared with the WAnT. When testing healthy college-aged individuals, the HART offers an easy and inexpensive alternative maximal effort anaerobic power test to other established tests. PMID:24126898

  7. Modeling for Anaerobic Fixed-Bed Biofilm Reactors

    SciTech Connect

    Liu, B. Y. M.; Pfeffer, J. T.

    1989-06-01

    The specific objectives of this research were: 1. to develop an equilibrium model for chemical aspects of anaerobic reactors; 2. to modify the equilibrium model for non-equilibrium conditions; 3. to incorporate the existing biofilm models into the models above to study the biological and chemical behavior of the fixed-film anaerobic reactors; 4. to experimentally verify the validity of these models; 5. to investigate the biomass-holding ability of difference packing materials for establishing reactor design criteria.

  8. Evaluation of the BBL Crystal Anaerobe identification system.

    PubMed Central

    Cavallaro, J J; Wiggs, L S; Miller, J M

    1997-01-01

    The BBL Crystal Anaerobe (ANR) identification system was evaluated, and the results were compared with those from conventional anaerobic methods. We tested 322 clinically significant anaerobic bacteria according to the manufacturer's instructions. The system identified correctly 286 of 322 (88.8%) of the anaerobic bacteria tested. Of these, 263 of 322 (81.7%) were identified correctly on initial testing and 49 were identified correctly only to the genus level; on repeat testing, 23 of 49 (46.9%) were identified correctly to both the genus and the species levels. A total of 26 (8.5%) were misidentified at the species level, and 10 (3.1%) were not identified. Performance characteristics for individual strains varied. The system correctly identified all tested strains of Campylobacter, Desulfomonas, Desulfovibrio, Leptotrichia, Mobiluncus, Peptostreptococcus, Porphyromonas, Provetella, Propionibacterium, Tisierella, and Veillonella and 36 of 37 (97.3%) Actinomyces strains, 42 of 46 (91.3%) B. fragilis group strains, 79 of 103 (76.7%) Clostridium strains, (however, the system failed to identify any of the 7 C. innocuum and 9 C. tetani strains tested), and 8 of 15 (53.3%) Bacteroides strains. This system was easy to use, did not involve the addition of reagents, and was faster than conventional anaerobic procedures. It would be a useful addition to the anaerobe laboratory of most hospitals. PMID:9399517

  9. Carbon and Hydrogen Isotopic Fractionation during Anaerobic Biodegradation of Benzene

    PubMed Central

    Mancini, Silvia A.; Ulrich, Ania C.; Lacrampe-Couloume, Georges; Sleep, Brent; Edwards, Elizabeth A.; Sherwood Lollar, Barbara

    2003-01-01

    Compound-specific isotope analysis has the potential to distinguish physical from biological attenuation processes in the subsurface. In this study, carbon and hydrogen isotopic fractionation effects during biodegradation of benzene under anaerobic conditions with different terminal-electron-accepting processes are reported for the first time. Different enrichment factors (ɛ) for carbon (range of −1.9 to −3.6‰) and hydrogen (range of −29 to −79‰) fractionation were observed during biodegradation of benzene under nitrate-reducing, sulfate-reducing, and methanogenic conditions. These differences are not related to differences in initial biomass or in rates of biodegradation. Carbon isotopic enrichment factors for anaerobic benzene biodegradation in this study are comparable to those previously published for aerobic benzene biodegradation. In contrast, hydrogen enrichment factors determined for anaerobic benzene biodegradation are significantly larger than those previously published for benzene biodegradation under aerobic conditions. A fundamental difference in the previously proposed initial step of aerobic versus proposed anaerobic biodegradation pathways may account for these differences in hydrogen isotopic fractionation. Potentially, C-H bond breakage in the initial step of the anaerobic benzene biodegradation pathway may account for the large fractionation observed compared to that in aerobic benzene biodegradation. Despite some differences in reported enrichment factors between cultures with different terminal-electron-accepting processes, carbon and hydrogen isotope analysis has the potential to provide direct evidence of anaerobic biodegradation of benzene in the field. PMID:12513995

  10. Anaerobic threshold: its concept and role in endurance sport.

    PubMed

    Ghosh, Asok Kumar

    2004-01-01

    aerobic to anaerobic transition intensity is one of the most significant physiological variable in endurance sports. Scientists have explained the term in various ways, like, Lactate Threshold, Ventilatory Anaerobic Threshold, Onset of Blood Lactate Accumulation, Onset of Plasma Lactate Accumulation, Heart Rate Deflection Point and Maximum Lactate Steady State. But all of these have great role both in monitoring training schedule and in determining sports performance. Individuals endowed with the possibility to obtain a high oxygen uptake need to complement with rigorous training program in order to achieve maximal performance. If they engage in endurance events, they must also develop the ability to sustain a high fractional utilization of their maximal oxygen uptake (%VO(2) max) and become physiologically efficient in performing their activity. Anaerobic threshold is highly correlated to the distance running performance as compared to maximum aerobic capacity or VO(2) max, because sustaining a high fractional utilization of the VO(2) max for a long time delays the metabolic acidosis. Training at or little above the anaerobic threshold intensity improves both the aerobic capacity and anaerobic threshold level. Anaerobic Threshold can also be determined from the speed-heart rate relationship in the field situation, without undergoing sophisticated laboratory techniques. However, controversies also exist among scientists regarding its role in high performance sports. PMID:22977357

  11. Sequential anaerobic/aerobic biotreatment of bark leachate.

    PubMed

    Frigon, J C; Cimpoia, R; Guiot, S R

    2003-01-01

    Bark leachate is generated from sawmill operations such as log storage sites and contains polymeric tannins, carbohydrates, organic acids, phenolic and resin compounds. The present study was aimed at assessing the performance of a sequential anaerobic and aerobic treatment, for both chemical oxygen demand (COD) and phenol removal, under various combinations of operational conditions, in the continuous mode. After anaerobic treatment in a five litres upflow anaerobic sludge bed (UASB) reactor, the leachate was directed into two parallel aerobic reactors, either an activated sludge unit or a fixed film submerged filter (packed with polyethylene Flexirings), both of a volume of one litre and oxygenated by air diffusion. For a leachate of 22 gCOD/l, an overall COD removal of 96-98% was achieved at an hydraulic residence time (HRT) of 4 days for the anaerobic reactor and one day for either aerobic systems. The phenol concentration generally increased after anaerobic treatment but was below the detection limit (50 ppb) after aerobic polishing. Radiorespirometric microcosms with 14C-labelled phenol confirmed that phenol was mineralized in the aerobic reactors. The performances of both aerobic systems were similar for COD and phenol removal. Thus, a sequential anaerobic/aerobic treatment was able to effectively address the contamination of a bark leachate discharge, including phenols. PMID:14640219

  12. Effect of alkaline pretreatment on anaerobic digestion of solid wastes.

    PubMed

    López Torres, M; Espinosa Lloréns, Ma del C

    2008-11-01

    The introduction of the anaerobic digestion for the treatment of the organic fraction of municipal solid waste (OFMSW) is currently of special interest. The main difficulty in the treatment of this waste fraction is its biotransformation, due to the complexity of organic material. Therefore, the first step must be its physical, chemical and biological pretreatment for breaking complex molecules into simple monomers, to increase solubilization of organic material and improve the efficiency of the anaerobic treatment in the second step. This paper describes chemical pretreatment based on lime addition (Ca(OH)2), in order to enhance chemical oxygen demand (COD) solubilization, followed by anaerobic digestion of the OFMSW. Laboratory-scale experiments were carried out in completely mixed reactors, 1 L capacity. Optimal conditions for COD solubilization in the first step of pretreatment were 62.0 mEq Ca(OH)2/L for 6.0 h. Under these conditions, 11.5% of the COD was solubilized. The anaerobic digestion efficiency of the OFMSW, with and without pretreatment, was evaluated. The highest methane yield under anaerobic digestion of the pretreated waste was 0.15 m3CH4/kg volatile solids (VS), 172.0% of the control. Under that condition the soluble COD and VS removal were 93.0% and 94.0%, respectively. The results have shown that chemical pretreatment with lime, followed by anaerobic digestion, provides the best results for stabilizing the OFMSW. PMID:18068345

  13. [Anaerobic digestion of animal manure contaminated by tetracyclines].

    PubMed

    Tong, Zi-Lin; Liu, Yuan-Lu; Hu, Zhen-Hu; Yuan, Shou-Jun

    2012-03-01

    Anaerobic digestion of pig manure spiked with tetracycline (TC) and chlortetracycline (CTC) and the degradation of the two antibiotics during the anaerobic digestion at 35 degrees C were investigated. The results indicate that propionate was the main volatile fatty acid produced during the anaerobic digestion followed by acetate. Compared with the CTC addition, TC + CTC addition showed obvious inhibitory effect on the hydrolysis and acidification of easily digestible organic components of pig manure. The cumulative methane production of TC, CTC, TC + CTC and CK2 during anaerobic digestion was 386.4 mL, 406.0 mL, 412.1 mL and 464.6 mL, respectively. Degradation of TC and CTC followed the first-order kinetic equation. The half-life of TC and CTC was 14-18 days and 10 days, respectively. After the treatment of 45-day anaerobic digestion, the degradation efficiency of TC was 88.6%-91.6% with 97.7%-98.2% of CTC. Therefore, anaerobic digestion shows the benefit on the management of animal manures contaminated by tetracyclines. PMID:22624404

  14. Decomposition of organic waste products under aerobic and anaerobic conditions

    SciTech Connect

    Gale, P.M.

    1988-01-01

    The objectives of this research were to determine the kinetics of C and N mineralization under aerobic and anaerobic conditions. These parameters were then used to verify the simulation model, DECOMPOSITION, for the anaerobic system. Incubation experiments were conducted to compare the aerobic and anaerobic decomposition of alfalfa (Medicago sativa L.), a substrate with a low C:N ratio. Under anaerobic conditions the net mineralization of N occurred more rapidly than that under aerobic conditions. However, the rate of C mineralization as measured by CO{sub 2} evolution was much lower. For the anaerobic decomposition of alfalfa, C mineralization was best described as the sum of the CO{sub 2} and CH{sub 4} evolved plus the water soluble organic C formed. The kinetics of C mineralization, as determined by this approach, were used to successfully predict the rate and amount of N mineralization from alfalfa undergoing anaerobic decomposition. The decomposition of paper mill sludge, a high C:N ratio substrate, was also evaluated.

  15. Reconstructing the mosaic glycolytic pathway of the anaerobic eukaryote Monocercomonoides.

    PubMed

    Liapounova, Natalia A; Hampl, Vladimir; Gordon, Paul M K; Sensen, Christoph W; Gedamu, Lashitew; Dacks, Joel B

    2006-12-01

    All eukaryotes carry out glycolysis, interestingly, not all using the same enzymes. Anaerobic eukaryotes face the challenge of fewer molecules of ATP extracted per molecule of glucose due to their lack of a complete tricarboxylic acid cycle. This may have pressured anaerobic eukaryotes to acquire the more ATP-efficient alternative glycolytic enzymes, such as pyrophosphate-fructose 6-phosphate phosphotransferase and pyruvate orthophosphate dikinase, through lateral gene transfers from bacteria and other eukaryotes. Most studies of these enzymes in eukaryotes involve pathogenic anaerobes; Monocercomonoides, an oxymonad belonging to the eukaryotic supergroup Excavata, is a nonpathogenic anaerobe representing an evolutionarily and ecologically distinct sampling of an anaerobic glycolytic pathway. We sequenced cDNA encoding glycolytic enzymes from a previously established cDNA library of Monocercomonoides and analyzed the relationships of these enzymes to those from other organisms spanning the major groups of Eukaryota, Bacteria, and Archaea. We established that, firstly, Monocercomonoides possesses alternative versions of glycolytic enzymes: fructose-6-phosphate phosphotransferase, both pyruvate kinase and pyruvate orthophosphate dikinase, cofactor-independent phosphoglycerate mutase, and fructose-bisphosphate aldolase (class II, type B). Secondly, we found evidence for the monophyly of oxymonads, kinetoplastids, diplomonads, and parabasalids, the major representatives of the Excavata. We also found several prokaryote-to-eukaryote as well as eukaryote-to-eukaryote lateral gene transfers involving glycolytic enzymes from anaerobic eukaryotes, further suggesting that lateral gene transfer was an important factor in the evolution of this pathway for denizens of this environment. PMID:17071828

  16. Effect of alkaline pretreatment on anaerobic digestion of solid wastes

    SciTech Connect

    Lopez Torres, M. Espinosa Llorens, Ma. del C.

    2008-11-15

    The introduction of the anaerobic digestion for the treatment of the organic fraction of municipal solid waste (OFMSW) is currently of special interest. The main difficulty in the treatment of this waste fraction is its biotransformation, due to the complexity of organic material. Therefore, the first step must be its physical, chemical and biological pretreatment for breaking complex molecules into simple monomers, to increase solubilization of organic material and improve the efficiency of the anaerobic treatment in the second step. This paper describes chemical pretreatment based on lime addition (Ca(OH){sub 2}), in order to enhance chemical oxygen demand (COD) solubilization, followed by anaerobic digestion of the OFMSW. Laboratory-scale experiments were carried out in completely mixed reactors, 1 L capacity. Optimal conditions for COD solubilization in the first step of pretreatment were 62.0 mEq Ca(OH){sub 2}/L for 6.0 h. Under these conditions, 11.5% of the COD was solubilized. The anaerobic digestion efficiency of the OFMSW, with and without pretreatment, was evaluated. The highest methane yield under anaerobic digestion of the pretreated waste was 0.15 m{sup 3} CH{sub 4}/kg volatile solids (VS), 172.0% of the control. Under that condition the soluble COD and VS removal were 93.0% and 94.0%, respectively. The results have shown that chemical pretreatment with lime, followed by anaerobic digestion, provides the best results for stabilizing the OFMSW.

  17. Carbon balance of anaerobic granulation process: carbon credit.

    PubMed

    Wong, Biing-Teo; Show, K Y; Lee, D J; Lai, J Y

    2009-03-01

    The concept of carbon credit arose out of increasing awareness of the need to reduce emissions of greenhouse gases to combat global warming which was formalized in the Kyoto protocol. In addition to contribution to sustainable development with energy recovery in the form of methane, carbon credits can be claimed by application of advanced anaerobic processes in wastewater treatment for reducing emissions of greenhouse gases. As anaerobic granular systems are capable of handling high organic loadings concomitant with high strength wastewater and short hydraulic retention time, they could render much more carbon credits than other conventional anaerobic systems. This study investigated the potential carbon credit derived from laboratory-scale upflow anaerobic sludge blanket (UASB) reactors based on a carbon balance analysis. Methane emission reduction could be calculated by calculating the difference of UASB reactors and open lagoon treatment systems. Based on the 2.5l bench-scale reactor, the total CH(4) emissions reduction was calculated as 29 kg CO(2)/year. On scaling up to a typical full-scale anaerobic digester, the total CH(4) emissions reduction could achieve 46,420 tons CO(2) reduction/year. The estimated carbon credits would amount to 278,500 US$ per year by assuming a carbon price of 6 US$ per metric ton CO(2) reduction. The analysis postulated that it is financially viable to invest in advanced anaerobic granular treatment system from the revenue generated from carbon credits. PMID:18990565

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

    PubMed

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

    2010-05-01

    Although the cultivable and noncultivable microbial diversity of spacecraft assembly clean rooms has been previously documented using conventional and state-of-the-art molecular techniques, the occurrence of obligate anaerobes within these clean rooms is still uncertain. Therefore, anaerobic bacterial communities of three clean-room facilities were analyzed during assembly of the Mars Science Laboratory rover. Anaerobic bacteria were cultured on several media, and DNA was extracted from suitable anaerobic enrichments and examined with conventional 16S rRNA gene clone library, as well as high-density phylogenetic 16S rRNA gene microarray (PhyloChip) technologies. The culture-dependent analyses predominantly showed the presence of clostridial and propionibacterial strains. The 16S rRNA gene sequences retrieved from clone libraries revealed distinct microbial populations associated with each clean-room facility, clustered exclusively within gram-positive organisms. PhyloChip analysis detected a greater microbial diversity, spanning many phyla of bacteria, and provided a deeper insight into the microbial community structure of the clean-room facilities. This study presents an integrated approach for assessing the anaerobic microbial population within clean-room facilities, using both molecular and cultivation-based analyses. The results reveal that highly diverse anaerobic bacterial populations persist in the clean rooms even after the imposition of rigorous maintenance programs and will pose a challenge to planetary protection implementation activities. PMID:20228115

  19. Characterizing the anaerobic response of Chlamydomonas reinhardtii by quantitative proteomics.

    PubMed

    Terashima, Mia; Specht, Michael; Naumann, Bianca; Hippler, Michael

    2010-07-01

    The versatile metabolism of the green alga Chlamydomonas reinhardtii is reflected in its complex response to anaerobic conditions. The anaerobic response is also remarkable in the context of renewable energy because C. reinhardtii is able to produce hydrogen under anaerobic conditions. To identify proteins involved during anaerobic acclimation as well as to localize proteins and pathways to the powerhouses of the cell, chloroplasts and mitochondria from C. reinhardtii in aerobic and anaerobic (induced by 8 h of argon bubbling) conditions were isolated and analyzed using comparative proteomics. A total of 2315 proteins were identified. Further analysis based on spectral counting clearly localized 606 of these proteins to the chloroplast, including many proteins of the fermentative metabolism. Comparative quantitative analyses were performed with the chloroplast-localized proteins using stable isotopic labeling of amino acids ([(13)C(6)]arginine/[(12)C(6)]arginine in an arginine auxotrophic strain). The quantitative data confirmed proteins previously characterized as induced at the transcript level as well as identified several new proteins of unknown function induced under anaerobic conditions. These proteins of unknown function provide new candidates for further investigation, which could bring insights for the engineering of hydrogen-producing alga strains. PMID:20190198

  20. Comparison of selected aerobic and anaerobic procedures for MSW treatment.

    PubMed

    Fricke, Klaus; Santen, Heike; Wallmann, Rainer

    2005-01-01

    This paper considers selected efficiency rates and process data of aerobic and anaerobic procedures for the treatment of municipal solid waste and residual waste. Data are exclusively related to mechanical-biological treatment (MBT) procedures for generating waste appropriate for landfilling. The following aspects are regarded: general framework conditions for the application of MBT, efficiency of decomposition and of stabilisation, air and water emissions and energy balances. The presented data can be used for more efficient planning. In comparison to aerobic processes, anaerobic digestion can be ecologically advantageous, particularly with regard to exhaust emissions and energy balances. On the other hand, the wastewater emissions and the wastewater treatment required must be regarded as disadvantageous. Due to the relatively short period of operational history of most anaerobic processes for mechanical-biological waste treatment and thus limited experiences, operational reliability of anaerobic processes is slightly lower. Extensive biological stability of the treated waste for low-emission disposal cannot be reached by anaerobic digestion alone, but only in combination with additional aerobic post-treatment. In connection with the utilisation of renewable energies and the rising relevancy of climate protection, it can be affirmed that anaerobic digestion for the treatment of municipal solid waste has a high potential for further development. PMID:16125060

  1. Anaerobic treatment of effluents from an industrial polymers synthesis plant

    SciTech Connect

    Araya, P.; Aroca, G.; Chamy, R.

    1999-06-01

    The feasibility of the anaerobic treatment of an industrial polymer synthesis plant effluent was evaluated. The composition of the wastewater includes acrylates, styrene, detergents, a minor amount of silicates and a significant amount of ferric chloride. The average chemical oxygen demand (COD) corresponding is about 2,000 mg/l. The anaerobic biodegradability of the effluent is shown and the toxicity effect on the populations of anaerobic bacteria is evaluated. The results of the anaerobic biodegradation assays show that 62% of the wastewater compounds, measured as COD, could be consumed. An upflow anaerobic sludge blanket (UASB) reactor was used in the evaluation, it has a diameter-height ratio of 1:7, and 4-liter volume. The inoculum was obtained from a UASB pilot plant that treats brewery wastewaters. At the beginning of the operation, the biomass showed an anaerobic activity of 0.58 gCOD/(gVSS {times} d), it decreased only 2.5% in the subsequent 4 months. After 35 days of continuous operation, the reactor was operated at different steady states for 140 days. The COD was maintained at 2,200 mg/l in the feed. The results were: organic loading rate (OLR): 4.3 kg COD/(m{sup 3} {times} d), hydraulic retention time: 12 h, superficial velocity: 1 m/h, average biogas productivity: 290 L CH{sub 4}/kg COD fed, biogas composition: 70--75% methane and a COD removal percentage > 75%.

  2. Clinical characteristics associated with mortality of patients with anaerobic bacteremia.

    PubMed

    Umemura, Takumi; Hamada, Yukihiro; Yamagishi, Yuka; Suematsu, Hiroyuki; Mikamo, Hiroshige

    2016-06-01

    The presence of anaerobes in the blood stream is known to be associated with a higher rate of mortality. However, few prognostic risk factor analyses examining whether a patient's background characteristics are associated with the prognosis have been reported. We performed a retrospective case-controlled study to assess the prognostic factors associated with death from anaerobic bacteremia. Seventy-four patients with anaerobic bacteremia were treated between January 2005 and December 2014 at Aichi Medical University Hospital. The clinical information included drug susceptibility was used for analysis of prognostic factors for 30-day mortality. Multivariate logistic analyses revealed an association between the 30-day mortality rate and malignancy (OR: 3.64, 95% CI: 1.08-12.31) and clindamycin resistance (OR: 7.93, 95% CI: 2.33-27.94). The result of Kaplan-Meier analysis of mortality showed that the 30-day survival rate was 83% in clindamycin susceptible and 38.1% in clindamycin resistant anaerobes causing bacteremia. The result of log-rank test also showed that susceptibility to clindamycin affected mortality (P < 0.001). Our results indicated that malignancy and clindamycin susceptibility could be used to identify subgroups of patients with anaerobic bacteremia with a higher risk of 30-day mortality. The results of this study are important for the early and appropriate management of patients with anaerobic bacteremia. PMID:26903282

  3. Hydrogen Biogeochemistry in Anaerobic and Photosynthetic Ecosystems

    NASA Technical Reports Server (NTRS)

    Hoehler, Tori M.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The simple biochemistry of molecular hydrogen is central to a large number of microbial processes, affecting the interaction of organisms with each other and with the environment. In anoxic sediments, a great majority of microbial redox processes involve hydrogen as a reactant, product or potential by-product. Accordingly, the energetics (thermodynamics) of each of these processes is affected by variations in local H2 concentrations. It has long been established that this effect is important in governing microbe-microbe interactions and there are multiple demonstrations that "interspecies hydrogen transfer" can alter the products of, inhibit/stimulate, or even reverse microbial metabolic reactions. In anoxic sediments, H2 concentrations themselves are thought to be controlled by the thermodynamics of the predominant H2-consuming microbial process. In sediments from Cape Lookout Bight, this relationship quantitatively describes the co-variation of H2 concentrations with temperature (for methanogens and sulfate reducers) and with sulfate concentration (for sulfate reducers). The quantitative aspect is import= for two reasons: 1) it permits the modeling of H2-sensitive biogeochemistry, such as anaerobic methane oxidation or pathways of organic matter remineralization, as a function of environmental controls; 2) for such a relationship to be observed requires that intracellular biochemistry and bioenergetics are being directly expressed in a component of the extracellular medium. H2 could therefore be utilized a non-invasive probe of cellular energetic function in intact microbial ecosystems. Based on the latter principle we have measured down-core profiles of H2 and other relevant physico-chemical parameters in order to calculate the metabolic energy yields (DG) that support microbial metabolism in Cape Lookout Bight sediments. Methanogens in this system apparently function with energy yields significantly smaller than the minimum requirements suggested by pure

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

    PubMed

    Suneethi, S; Joseph, Kurian

    2011-10-01

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

  5. Anaerobic biotransformation of trichlorofluoroethene in groundwater microcosms

    SciTech Connect

    Vancheeswaran, S.; Semprini, L. . Dept. of Civil, Construction, and Environmental Engineering); Hyman, M.R. . Dept. of Microbiology)

    1999-06-15

    The biological reduction of trichlorofluoroethene (TCFE) was investigated in anaerobic groundwater microcosms. TCFE was reductively dehalogenated by microorganisms to produce three dichlorofluoroethene isomers, with cis-1,2-dichlorofluoroethene (c-DCFE) being the main isomer formed. Further sequential biological transformation of these compounds to mono-chlorofluoroethene isomers was incomplete and occurred at much slower rates. The rates of TCFE reduction were compared to the rates of reduction of two common chlorinated solvents, perchloroethene (PCE) and trichloroethene (TCE), when present at similar concentrations. Aqueous concentrations ranged from 7.0 to 14.0 mg/L for TCFE and from 7.5 to 15.0 mg/L for PCE and TCE. Similar rates of PCE and TCE transformation relative to TCFE were observed in single-compound tests (PCE, TCE, and TCFE in separate microcosms) and when the contaminants were present together as mixtures in the microcosms. The close similarities between the time course and kinetics of TCFE degradation and the degradation of both PCE and TCE, when present at comparable initial concentrations, suggest that TCFE could potentially be used as a benign reactive tracer to measure in-situ rates of PCE and TCE transformation in contaminated environments.

  6. Mechanisms of foam formation in anaerobic digesters.

    PubMed

    Subramanian, Bhargavi; Pagilla, Krishna R

    2015-02-01

    An anaerobic digester (AD) is the most essential step to generate energy in the form of biogas from waste. AD foaming is widespread and leads to deterioration of the AD process and operation. In extreme conditions, AD foaming poses a significant safety risk and considerable economic impacts. It is, therefore, necessary to understand the fundamentals of AD foaming to develop effective strategies that can help minimize the foaming impacts. Several aspects of AD foaming have attracted considerable research attention, however, the focused has been mainly on site specific causes and prevention. Here, the available three-phase foam literature is reviewed with an emphasis on the fundamental aspects of bubble formation in AD: similarities between AD foams and other "desirable" foams, surface rheology, physico-chemical aspects of carbon dioxide (CO2) in digesters, dynamics of the gas-phase, pH, alkalinity and certain relationships between these factors are discussed. All of the abovementioned fundamental aspects seem to be involved in AD foam formation. However, the detailed relationship between these uncontrolled and controlled factors, foam formation and its implications for process and operation of AD is still inconclusive. PMID:25487880

  7. Anaerobic degradation of linoleic oleic acids

    SciTech Connect

    Lalman, J.A.; Bagley, D.M.

    1999-07-01

    The anaerobic degradation of linoleic (C18:2) and oleic (C18:1) acids was examined in batch experiments. By-product distribution depended on both the type of long chain fatty acid added and initial substrate concentration. Major by-products were palmitic (C16), myristic (C14) and acetic acids. Trace quantities of palmitoleic (C16:1) and lauric (C12) acids were observed together with larger amounts of palmitic (C16), myristic (C14) and hexanoic (C6) acids in cultures incubated with 100 mg/L linoleic (C18:2) acid. Bio-hydrogenation of C18 fatty acids was not necessary for the {beta}-oxidation mechanism to proceed. Aceticlastic methanogenic inhibition was observed in cultures inoculated with greater than 50 mg/L linoleic (C18:2) acid. In cultures incubated with greater than 50 mg/L oleic (C18:1) acid, aceticlastic methanogenic inhibition was observed for a short time period.

  8. Molecular mechanism of anaerobic ammonium oxidation.

    PubMed

    Kartal, Boran; Maalcke, Wouter J; de Almeida, Naomi M; Cirpus, Irina; Gloerich, Jolein; Geerts, Wim; Op den Camp, Huub J M; Harhangi, Harry R; Janssen-Megens, Eva M; Francoijs, Kees-Jan; Stunnenberg, Hendrik G; Keltjens, Jan T; Jetten, Mike S M; Strous, Marc

    2011-11-01

    Two distinct microbial processes, denitrification and anaerobic ammonium oxidation (anammox), are responsible for the release of fixed nitrogen as dinitrogen gas (N(2)) to the atmosphere. Denitrification has been studied for over 100 years and its intermediates and enzymes are well known. Even though anammox is a key biogeochemical process of equal importance, its molecular mechanism is unknown, but it was proposed to proceed through hydrazine (N(2)H(4)). Here we show that N(2)H(4) is produced from the anammox substrates ammonium and nitrite and that nitric oxide (NO) is the direct precursor of N(2)H(4). We resolved the genes and proteins central to anammox metabolism and purified the key enzymes that catalyse N(2)H(4) synthesis and its oxidation to N(2). These results present a new biochemical reaction forging an N-N bond and fill a lacuna in our understanding of the biochemical synthesis of the N(2) in the atmosphere. Furthermore, they reinforce the role of nitric oxide in the evolution of the nitrogen cycle. PMID:21964329

  9. Comparison of four commercial brucella agar media for growth of anaerobic organisms.

    PubMed Central

    Mangels, J I; Douglas, B P

    1989-01-01

    Four different commercial brucella blood agar plating media (Anaerobe Systems, BBL Microbiology Systems, Remel, and Scott Laboratories) were compared for the abilities to recover anaerobic organisms from clinical specimens and to support the growth of American Type Culture Collection anaerobic stock cultures. Following 24 h of incubation in an anaerobe chamber, Anaerobe Systems prereduced, anaerobically sterilized brucella plates yielded 63% of the total clinical anaerobe isolates, the Scott medium yielded 51%, the Remel medium yielded 42%, and the BBL medium yielded 37%. Poor growth of Peptostreptococcus magnus, P. anaerobius, Fusobacterium necrophorum, F. nucleatum, and pigmented Bacteroides spp. was observed on brucella media obtained from BBL, Remel, and Scott. Data obtained with stock anaerobic cultures showed that Anaerobe Systems plates yielded good growth and produced a larger colony size with all of the strains tested in 1 day, whereas poor growth of Peptostreptococcus spp., B. melaninogenicus, and Fusobacterium spp. was noted on brucella media from BBL, Remel, and Scott. PMID:2584378

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

    PubMed

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

    2015-06-01

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

  11. Evaluation of PCB dechlorination pathways in anaerobic sediment microcosms using an anaerobic dechlorination model.

    PubMed

    Demirtepe, Hale; Kjellerup, Birthe; Sowers, Kevin R; Imamoglu, Ipek

    2015-10-15

    A detailed quantitative analysis of anaerobic dechlorination (AD) pathways of polychlorinated biphenyls (PCBs) in sediment microcosms was performed by applying an anaerobic dechlorination model (ADM). The purpose of ADM is to systematically analyze changes in a contaminant profile that result from microbial reductive dechlorination according to empirically determined dechlorination pathways. In contrast to prior studies that utilized modeling tools to predict dechlorination pathways, ADM also provides quantification of individual pathways. As only microbial reductive dechlorination of PCBs occurred in the modeled laboratory microcosms, extensive analysis of AD pathways was possible without the complicating effect of concurrent physico-chemical or other weathering mechanisms. The results from this study showed: (1) ninety three AD pathways are active; (2) tetra- to hepta-chlorobiphenyl (CB) congeners were common intermediates in several AD pathways, penta-CBs being the most frequently observed; (3) the highest rates of dechlorination were for penta-CB homologs during the initial 185 days; (4) the dominant terminal products of AD were PCB 32(26-4), 49(24-25), 51(24-26), 52(25-25), 72(25-35), 73(26-35) and 100(246-24), (5) potential toxicity of the sediment was reduced. ADM serves as a powerful tool not only for a thorough analysis of AD pathways, but also for providing necessary input for numerical fate models (as a degradation term) that investigate dechlorination products or outcome of natural attenuation, or bioremediation/bioaugmentation of PCB-impacted sediments. PMID:25913678

  12. Rheological behaviors of anaerobic granular sludge in a spiral symmetry stream anaerobic bioreactor.

    PubMed

    Chen, Xiaoguang; Dai, Ruobin; Xiang, Xinyi; Ma, Chengyu; Li, Gang; Hu, Tao; Xu, Zhengqi; Abdelgadir, Awad

    2015-01-01

    The rheological behaviors of the anaerobic granular sludge (AGS) in a spiral symmetry stream anaerobic bioreactor (SSSAB) were investigated. Shear-thinning behavior, thixotropic behavior, concentration-viscosity behavior and temperature-viscosity behavior were evaluated based on the constitutive equation of the AGS. The results indicated that the Herschel-Bulkley model was able to adequately describe the constitutive relation of AGS in the SSSAB. The AGS also showed shear-thinning behavior as well as thixotropic behavior. The critical shear rate and network strength of the AGS were 61.8 s(-1) and 497.0 W m(-3), respectively. The relationship between the apparent viscosity and the sludge concentration was illustrated and explained by the Woodcock formula. The relationship between apparent viscosity of the AGS and temperature could be modeled using the Arrhenius equation. The AGS was significantly thermo-sensitive and its mean energy of activation was 14.640 kJ mol(-1). Notably, it was necessary to consider such behaviors in the hydrodynamic modeling of SSSAB in which shear condition, sludge concentration and temperature were in non-uniform distribution. PMID:26247766

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

    PubMed Central

    Brook, I

    1998-01-01

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

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

    PubMed

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

    2011-10-01

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

  15. Anaerobic digestion for energy production and environmental protection

    SciTech Connect

    Lettinga, G.; Haandel, A.C. Vaan

    1993-12-31

    Anaerobic digestion is the decomposition of complex molecules into simpler substances by micro-organisms in the absence of oxygen. Anaerobic digestion processes can be employed for resource conservation, for the production of biogas and other useful end products from biomass, and for environmental protection through waste and wastewater treatment. Modern high-rate anaerobic wastewater-treatment processes can effectively remove organic pollutants from wastewater at a cost far below that of conventional aerobic processes. These anaerobic wastewater treatment processes can also be profitably applied for the generation of biogas from energy crops such as sugarcane. In fact, these methods might even be an attractive alternative for the alcohol fermentation extensively employed in Brazil for the production of fuel alcohol from sugarcane. The potential of modern anaerobic processes for this purpose has not yet been widely recognized. This paper describes the principles and use of these processes and demonstrates their prospects for producing energy from sugarcane (1) by treating vinasse, the wastewater generated during the production of ethanol from sugarcane, and (2) as a direct method for producing biogas from sugarcane juice.

  16. A review of anaerobic treatment of saline wastewater.

    PubMed

    Xiao, Yeyuan; Roberts, Deborah J

    2010-01-01

    Large volumes of saline (> 2% w/v NaCl) wastewaters are discharged from many industries; e.g. seafood processing, textile dyeing, oil and gas production, tanneries and drinking water treatment processes. Although anaerobic treatment would be the most cost-effective and sustainable technology for the treatment of many of these saline wastewaters, the salinity is considered to be inhibitory to anaerobic biological treatment processes. The recent applications of salt-tolerant cultures for the treatment of wastewaters from seafood processing and ion-exchange processes suggest that biological systems can be used to treat salty wastewaters. Additionally, organisms capable of anaerobic degradation of contaminants in saline solutions have been observed in marine sediments and have been characterized during the last two decades. This manuscript provides a review of the recent research on anaerobic treatment of saline wastewater and bacterial consortia capable of the anaerobic degradation of pollutants in saline solutions, documenting that the biological treatment of saline wastewaters is promising. PMID:20662390

  17. Anaerobic bioleaching of metals from waste activated sludge.

    PubMed

    Meulepas, Roel J W; Gonzalez-Gil, Graciela; Teshager, Fitfety Melese; Witharana, Ayoma; Saikaly, Pascal E; Lens, Piet N L

    2015-05-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342 μg g(-1) of copper, 487 μg g(-1) of lead, 793 μg g(-1) of zinc, 27 μg g(-1) of nickel and 2.3 μg g(-1) of cadmium. During the anaerobic acidification of 3 gdry weight L(-1) waste activated sludge, 80-85% of the copper, 66-69% of the lead, 87% of the zinc, 94-99% of the nickel and 73-83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead. PMID:25659306

  18. Anaerobic Fungi and Their Potential for Biogas Production.

    PubMed

    Dollhofer, Veronika; Podmirseg, Sabine Marie; Callaghan, Tony Martin; Griffith, Gareth Wyn; Fliegerová, Kateřina

    2015-01-01

    Plant biomass is the largest reservoir of environmentally friendly renewable energy on earth. However, the complex and recalcitrant structure of these lignocellulose-rich substrates is a severe limitation for biogas production. Microbial pro-ventricular anaerobic digestion of ruminants can serve as a model for improvement of converting lignocellulosic biomass into energy. Anaerobic fungi are key players in the digestive system of various animals, they produce a plethora of plant carbohydrate hydrolysing enzymes. Combined with the invasive growth of their rhizoid system their contribution to cell wall polysaccharide decomposition may greatly exceed that of bacteria. The cellulolytic arsenal of anaerobic fungi consists of both secreted enzymes, as well as extracellular multi-enzyme complexes called cellulosomes. These complexes are extremely active, can degrade both amorphous and crystalline cellulose and are probably the main reason of cellulolytic efficiency of anaerobic fungi. The synergistic use of mechanical and enzymatic degradation makes anaerobic fungi promising candidates to improve biogas production from recalcitrant biomass. This chapter presents an overview about their biology and their potential for implementation in the biogas process. PMID:26337843

  19. In vitro evaluation of faropenem activity against anaerobic bacteria.

    PubMed

    Behra-Miellet, J; Dubreuil, L; Bryskier, A

    2005-02-01

    Faropenem, a new oral penem with broad spectrum activity, could be used as empirical treatment in infections due to unidentified anaerobes, but only a few investigations have been carried out on these bacteria. The aim of this study was to compare faropenem in vitro activity with that of positive antimicrobial controls (metronidazole, imipenem, meropenem, amoxicillin, amoxicillin-clavulanic acid, ticarcillin-clavulanic acid, cefotetan, cefoxitin and clindamycin) against 462 anaerobic bacterial strains. The reference agar dilution method was used according to the NCCLS standard. Faropenem demonstrated high antimicrobial activity, similar to that of both imipenem and meropenem (faropenem Minimal Inhibitory Concentrations 50% and 90% were 0.12 and 1 mg/L for all Gram-negative anaerobes, 0.25 and 1 mg/L for all Gram-positive anaerobes). Only 5 strains of the Bacteroides fragilis group (1.1% of all anaerobes) were resistant to faropenem, which compared favorably with that of other reference antianaerobic drugs. The results obtained confirm those previously reported. PMID:15828442

  20. Biogas production from anaerobic digestion of Spirulina maxima algal biomass

    SciTech Connect

    Samson, R.; LeDuy, A.

    1982-08-01

    The photosynthetic spectrum of solar energy could be exploited for the production of chemical energy of methane through the combined algal-bacterial process. In this process, the algae are mass produced from light and from carbon in the first step. The algal biomass is then used as a nutrient for feeding the anaerobic digester, in the second step, for the production of methane by anaerobic bacteria. The carbon source for the production of algal biomass could be either organic carbon from wastewaters (for eucaryotic algae), or carbon dioxide from the atmosphere or from the combustion exhaust gases (for both prokaryotic and eukaryotic algae). The technical feasibility data on the anaerobic digestion of algal biomass have been reported for many species of algae including macroscopic algae and microscopic algae. Research being conducted in the authors' laboratory consists of using the semimicroscopic blue-green alga Spirulina maxima as the sole substrate for this combined algal-bacterial process. This species of alga is very attractive for the process because of its capability of using the atmospheric carbon dioxide as carbon source and its simple harvesting methods. Furthermore, it appeared that the fermentability of S. maxima is significantly higher than other microscopic algae. This communication presents the results on the anaerobic inoculum development by the adaptation technique. This inoculum was then used for the semicontinuous anaerobic digestion of S. maxima algal biomass. The evolutions of biogas production and composition, biogas yield, total volatile fatty acids, alkalinity, ammonia nitrogen, pH, and electrode potential were followed.

  1. Aerobic and anaerobic PCB biodegradation in the environment

    SciTech Connect

    Abramowicz, D.A.

    1995-06-01

    Studies have identified two distinct biological processes capable of biotransforming polychlorinated biphenyls (PCBs): aerobic oxidative processes and anaerobic reductive processes. It is now known that these two complementary activities are occurring naturally in the environment. Anaerobic PCB dechlorination, responsible for the conversion of highly chlorinated PCBs to lightly chlorinated ortho-enriched congeners, has been documented extensively in the Hudson River and has been observed at many other sites throughout the world. The products from this anaerobic process are readily degradable by a wide range of aerobic bacteria, and it has now been shown that this process is occurring in surficial sediments in the Hudson River. The widespread anaerobic dechlorination of PCBs that has been observed in many river and marine sediments results in reduction of both the potential risk from and potential exposure to PCBs. The reductions in potential risk include reduced dioxin like toxicity and reduced carcinogenicity. The reduced PCB exposure realized upon dechlorination is manifested by reduced bioaccumulation in the food chain and by the increased anaerobic degradability of these products. 27 refs., 1 fig., 1 tab.

  2. Anaerobic biosynthesis of the lower ligand of vitamin B12

    PubMed Central

    Hazra, Amrita B.; Han, Andrew W.; Mehta, Angad P.; Mok, Kenny C.; Osadchiy, Vadim; Begley, Tadhg P.; Taga, Michiko E.

    2015-01-01

    Vitamin B12 (cobalamin) is required by humans and other organisms for diverse metabolic processes, although only a subset of prokaryotes is capable of synthesizing B12 and other cobamide cofactors. The complete aerobic and anaerobic pathways for the de novo biosynthesis of B12 are known, with the exception of the steps leading to the anaerobic biosynthesis of the lower ligand, 5,6-dimethylbenzimidazole (DMB). Here, we report the identification and characterization of the complete pathway for anaerobic DMB biosynthesis. This pathway, identified in the obligate anaerobic bacterium Eubacterium limosum, is composed of five previously uncharacterized genes, bzaABCDE, that together direct DMB production when expressed in anaerobically cultured Escherichia coli. Expression of different combinations of the bza genes revealed that 5-hydroxybenzimidazole, 5-methoxybenzimidazole, and 5-methoxy-6-methylbenzimidazole, all of which are lower ligands of cobamides produced by other organisms, are intermediates in the pathway. The bza gene content of several bacterial and archaeal genomes is consistent with experimentally determined structures of the benzimidazoles produced by these organisms, indicating that these genes can be used to predict cobamide structure. The identification of the bza genes thus represents the last remaining unknown component of the biosynthetic pathway for not only B12 itself, but also for three other cobamide lower ligands whose biosynthesis was previously unknown. Given the importance of cobamides in environmental, industrial, and human-associated microbial metabolism, the ability to predict cobamide structure may lead to an improved ability to understand and manipulate microbial metabolism. PMID:26246619

  3. Prevailing Torque Locking Feature in Threaded Fasteners Using Anaerobic Adhesive

    NASA Technical Reports Server (NTRS)

    Hernandez, Alan; Hess, Daniel P.

    2016-01-01

    This paper presents results from tests to assess the use of anaerobic adhesive for providing a prevailing torque locking feature in threaded fasteners. Test procedures are developed and tests are performed on three fastener materials, four anaerobic adhesives, and both unseated assembly conditions. Five to ten samples are tested for each combination. Tests for initial use, reuse without additional adhesive, and reuse with additional adhesive are performed for all samples. A 48-hour cure time was used for all initial use and reuse tests. Test data are presented as removal torque versus removal angle with the specification required prevailing torque range added for performance assessment. Percent specification pass rates for the all combinations of fastener material, adhesive, and assembly condition are tabulated and reveal use of anaerobic adhesive as a prevailing torque locking feature is viable. Although not every possible fastener material and anaerobic adhesive combination provides prevailing torque values within specification, any combination can be assessed using the test procedures presented. Reuse without additional anaerobic adhesive generally provides some prevailing torque, and in some cases within specification. Reuse with additional adhesive often provides comparable removal torque data as in initial use.

  4. Anaerobic sequencing batch reactor treatment of coal conversion wastewaters

    SciTech Connect

    Ketchum, L.H. Jr.; Earley, J.P.; Shen, Yutao.

    1989-09-01

    The work proposed is a laboratory investigation of the AnSBR (Anaerobic Sequencing Batch Reactors) for treatment of a synthetic coal conversion wastewater. Two different strategies will be pursued. First, an AnSBR will be operated to simulate the Anaerobic Up-flow Sludge Blanket Reactor in an attempt to develop a readily settleable granular sludge. Second, operating strategies will be sought to optimize treatment, without attempting to develop settleable granular sludge. These systems will require development of more elaborate decanting mechanisms, probably including use of tube settler technology. We will use: (1) screening tests to identify compounds which are amenable to anaerobic degradation; (2) to determine those which are toxic or have an inhibitory effect; and (3) to identify the dilution required to achieve anaerobic degradation of the synthetic waste water; acclimation tests of organisms collected from different sources to the synthetic coal conversion wastewater; and Automatic Laboratory AnSBR studies. A 4-liter reactor will be operated to maintain a settleable granular anaerobic sludge when treating the synthetic coal conversion wastewater. 72 refs., 238 figs., 22 tabs.

  5. Foaming phenomenon in bench-scale anaerobic digesters.

    PubMed

    Siebels, Amanda M; Long, Sharon C

    2013-04-01

    The Madison Metropolitan Sewerage District (The District) in Madison, Wisconsin has been experiencing seasonal foaming in their anaerobic biosolids digesters, which has occurred from mid-November to late June for the past few years. The exact cause(s) of foaming is unknown. Previous research findings are unclear as to whether applications of advanced anaerobic digestion processes reduce the foaming potential of digesters. The object of this study was to investigate how configurations of thermophilic and acid phase-thermophilic anaerobic digestion would affect foaming at the bench-scale level compared to single stage mesophilic digestion for The District. Bench-scale anaerobic digesters were fed with a 4 to 4.5% by dry weight of solids content blend of waste activated sludge (WAS) and primary sludge from The District. Foaming potential was monitored using Alka-Seltzer and aeration foaming tests. The bench-scale acid phase-thermophilic digester had a higher foaming potential than the bench-scale mesophilic digester. These results indicate that higher temperatures increase the foaming potential of the bench-scale anaerobic digesters. The bench-scale acid phase-thermophilic digesters had a greater percent (approximately 5 to 10%) volatile solids destruction and a greater percent (approximately 5 to 10%) total solids destruction when compared to the bench-scale mesophilic digester. Overall, for the full-scale foaming experienced by The District, it appears that adding an acid phase or switching to thermophilic digestion would not alleviate The District's foaming issues. PMID:23697241

  6. Anaerobic treatability of waste water from pulp and paper industries.

    PubMed

    Norrman, J; Narbuvold, R; Nyström, L

    1984-01-01

    A black liquor evaporator condensate from a Kraft mill and a waste water from production of corrugating medium were anaerobically treated on a laboratory scale. The composition of the waste waters was determined before and after treatment in fixed bed reactors. Toxicity studies by the Microtox-method showed that both waste waters were highly toxic and a slight decrease in toxicity was achieved by anaerobic treatment. Despite the toxicity efficient anaerobic treatment was obtained. Major components of the condensate were methanol, ethanol, acetone, guaiacol, hydrogen sulfide and dimethyl disulfide. Anaerobic treatment reduced the concentration of the major components considerably with one exception. The concentration of hydrogen sulfide was unchanged. Organic overloading of the fixed bed reactor or a temperature drop resulted in an accumulation of acetone, although methanol and ethanol were degraded. Major components of the waste water from the production of corrugating medium were: Klason-lignin, acid-soluble lignin, carbohydrates, extractives and ash. When the fixed bed reactor was operated at a volumetric load of 1.6 kg COD/m(3).d the following reductions were obtained: Klason - lignin (solids fraction 84%; soluble and colloidal fraction 76%), acid-soluble lignin (solids fraction 56%; soluble and colloidal fraction 7%), carbohydrates (100%), extractives (71%), total-S (80%), COD (73%) and BOD(7) (78%). Kinetic studies showed that condensate was more easily degraded anaerobically than corrugating medium waste water. PMID:14545703

  7. Susceptibility testing of anaerobic bacteria: myth, magic, or method?

    PubMed Central

    Wexler, H M

    1991-01-01

    The demand for susceptibility testing of anaerobes has increased, yet consensus as to procedure and interpretation in this area has not been achieved. While routine testing of anaerobic isolates is not needed, certain isolates in specific clinical settings should be tested. Also, laboratories may monitor their local antibiograms by doing periodic surveillance batch testing. The National Committee for Clinical Laboratory Standards has published a protocol of methods approved for susceptibility testing of anaerobic bacteria. Both agar and broth microdilution are included; however, the broth disk elution method is no longer approved by the National Committee for Clinical Laboratory Standards because of method-related interpretive errors. A number of newer methods are undergoing evaluation and seem promising. Clinicians and microbiologists reviewing susceptibility reports should be aware of sources of variability in the test results. Variables in susceptibility testing of anaerobes include the media and methods used, organisms chosen for testing, breakpoints chosen for interpretation, antibiotic, and determination of endpoint. Clustering of MICs around the breakpoint may lead to significant variability in test results. Adherence of testing laboratories to approved methods and careful descriptions of the method and the breakpoints used for interpretation would facilitate interlaboratory comparisons and allow problems of emerging resistance to be noted. A variety of resistance mechanisms occurs in anaerobic bacteria, including the production of beta-lactamase and other drug-inactivating enzymes, alteration of target proteins, and inability of the drug to penetrate the bacterial wall. Antimicrobial resistance patterns in the United States and abroad are described. PMID:1747863

  8. Effect of respiratory warm-up on anaerobic power

    PubMed Central

    Özdal, Mustafa; Bostanci, Özgür; Dağlioğlu, Önder; Ağaoğlu, Seydi Ahmet; Kabadayi, Menderes

    2016-01-01

    [Purpose] The aim of the present study was to examine the effects of respiratory muscle warm-up on anaerobic power. [Subjects and Methods] Thirty male field hockey players (age, 20.5 ± 2.0 years) each participated in a control (CAN) trial and an experimental (EAN) trial. The EAN trial involved respiratory muscle warm-up, while the CAN trial did not. Anaerobic power was measured using the Wingate protocol. Paired sample t-tests were used to compare the EAN and CAN trials. [Results] There were significant increases in peak power and relative peak power, and decreases in the time to peak after the EAN trial by 8.9%, 9.6%, and 28.8% respectively. [Conclusion] Respiratory muscle warm-up may positively affect anaerobic power due to faster attainment of peak power. PMID:27512273

  9. The IWA Anaerobic Digestion Model No 1 (ADM1).

    PubMed

    Batstone, D J; Keller, J; Angelidaki, I; Kalyuzhnyi, S V; Pavlostathis, S G; Rozzi, A; Sanders, W T M; Siegrist, H; Vavilin, V A

    2002-01-01

    The IWA Anaerobic Digestion Modelling Task Group was established in 1997 at the 8th World Congress on Anaerobic Digestion (Sendai, Japan) with the goal of developing a generalised anaerobic digestion model. The structured model includes multiple steps describing biochemical as well as physicochemical processes. The biochemical steps include disintegration from homogeneous particulates to carbohydrates, proteins and lipids; extracellular hydrolysis of these particulate substrates to sugars, amino acids, and long chain fatty acids (LCFA), respectively; acidogenesis from sugars and amino acids to volatile fatty acids (VFAs) and hydrogen; acetogenesis of LCFA and VFAs to acetate; and separate methanogenesis steps from acetate and hydrogen/CO2. The physico-chemical equations describe ion association and dissociation, and gas-liquid transfer. Implemented as a differential and algebraic equation (DAE) set, there are 26 dynamic state concentration variables, and 8 implicit algebraic variables per reactor vessel or element. Implemented as differential equations (DE) only, there are 32 dynamic concentration state variables. PMID:12188579

  10. Acetate Metabolism in Anaerobes from the Domain Archaea.

    PubMed

    Ferry, James G

    2015-01-01

    Acetate and acetyl-CoA play fundamental roles in all of biology, including anaerobic prokaryotes from the domains Bacteria and Archaea, which compose an estimated quarter of all living protoplasm in Earth's biosphere. Anaerobes from the domain Archaea contribute to the global carbon cycle by metabolizing acetate as a growth substrate or product. They are components of anaerobic microbial food chains converting complex organic matter to methane, and many fix CO2 into cell material via synthesis of acetyl-CoA. They are found in a diversity of ecological habitats ranging from the digestive tracts of insects to deep-sea hydrothermal vents, and synthesize a plethora of novel enzymes with biotechnological potential. Ecological investigations suggest that still more acetate-metabolizing species with novel properties await discovery. PMID:26068860

  11. Anaerobic Metabolism in Haloferax Genus: Denitrification as Case of Study.

    PubMed

    Torregrosa-Crespo, J; Martínez-Espinosa, R M; Esclapez, J; Bautista, V; Pire, C; Camacho, M; Richardson, D J; Bonete, M J

    2016-01-01

    A number of species of Haloferax genus (halophilic archaea) are able to grow microaerobically or even anaerobically using different alternative electron acceptors such as fumarate, nitrate, chlorate, dimethyl sulphoxide, sulphide and/or trimethylamine. This metabolic capability is also shown by other species of the Halobacteriaceae and Haloferacaceae families (Archaea domain) and it has been mainly tested by physiological studies where cell growth is observed under anaerobic conditions in the presence of the mentioned compounds. This work summarises the main reported features on anaerobic metabolism in the Haloferax, one of the better described haloarchaeal genus with significant potential uses in biotechnology and bioremediation. Special attention has been paid to denitrification, also called nitrate respiration. This pathway has been studied so far from Haloferax mediterranei and Haloferax denitrificans mainly from biochemical point of view (purification and characterisation of the enzymes catalysing the two first reactions). However, gene expression and gene regulation is far from known at the time of writing this chapter. PMID:27134021

  12. Defining Anaerobic Digestion Stability-Full Scale Study

    NASA Astrophysics Data System (ADS)

    Demitry, M. E., Sr.

    2014-12-01

    A full-scale anaerobic digester receiving a mixture of primary and secondary sludge was monitored for one hundred days. A chemical oxygen demand, COD, and a volatile solids, VS, mass balance was conducted to evaluate the stability of the digester and its capability of producing methane gas. The COD mass balance could account for nearly 90% of the methane gas produced while the VS mass balance showed that 91% of the organic matter removed resulted in biogas formation. Other parameters monitored included: pH, alkalinity, VFA, and propionic acid. The values of these parameters showed that steady state had occurred. Finally, at mesophilic temperature and at steady state performance, the anaerobic digester stability was defined as a constant ratio of methane produced per substrate of ΔVS (average ratio=0.404 l/g). This ratio can be used as universal metric to determine the anaerobic digester stability in an easy and inexpensive way.

  13. Anaerobic biotransformation of organoarsenical pesticides monomethylarsonic acid and dimethylarsinic acid

    USGS Publications Warehouse

    Sierra-Alvarez, R.; Yenal, U.; Feld, J.A.; Kopplin, M.; Gandolfi, A.J.; Garbarino, J.R.

    2006-01-01

    Monomethylarsonic acid (MMAV) and dimethylarsinic acid (DMAV) are extensively utilized as pesticides, introducing large quantities of arsenic into the environment. Once released into the environment, these organoarsenicals are subject to microbial reactions. Aerobic biodegradation of MMAV and DMAV has been evaluated, but little is known about their fate in anaerobic environments. The objective of this study was to evaluate the biotransformation of MMAV and DMAV in anaerobic sludge. Biologically mediated conversion occurred under methanogenic or sulfate-reducing conditions but not in the presence of nitrate. Monomethylarsonous acid (MMAIII) was consistently observed as an important metabolite of MMAV degradation, and it was recovered in molar yields ranging from 5 to 47%. The main biotransformation product identified from DMAV metabolism was MMAV, which was recovered in molar yields ranging from 8 to 65%. The metabolites indicate that reduction and demethylation are important steps in the anaerobic bioconversion of MMAV and DMAV, respectively. ?? 2006 American Chemical Society.

  14. Anaerobic digestion of microalgal biomass: Challenges, opportunities and research needs.

    PubMed

    Gonzalez-Fernandez, Cristina; Sialve, Bruno; Molinuevo-Salces, Beatriz

    2015-12-01

    Integration of anaerobic digestion (AD) with microalgae processes has become a key topic to support economic and environmental development of this resource. Compared with other substrates, microalgae can be produced close to the plant without the need for arable lands and be fully integrated within a biorefinery. As a limiting step, anaerobic hydrolysis appears to be one of the most challenging steps to reach a positive economic balance and to completely exploit the potential of microalgae for biogas and fertilizers production. This review covers recent investigations dealing with microalgae AD and highlights research opportunities and needs to support the development of this resource. Novel approaches to increase hydrolysis rate, the importance of the reactor design and the noteworthiness of the microbial anaerobic community are addressed. Finally, the integration of AD with microalgae processes and the potential of the carboxylate platform for chemicals and biofuels production are reviewed. PMID:26454349

  15. Anaerobic Biotransformation and Mobility of Pu and PuEDTA

    SciTech Connect

    Xun, Luying

    2005-06-01

    Although our goal is to isolate anaerobic EDTA degraders, we initiated the experiments to include nitrilotriacetate (NTA), which is a structure homologue of EDTA. All the aerobic EDTA degraders can degrade NTA, but the isolated NTA degraders cannot degrade EDTA. Since NTA is a simpler structure homologue, it is likely that EDTA-degrading ability is evolved from NTA degradation. This hypothesis is further supported from our characterization of EDTA and NTA-degrading enzymes and genes (J. Bact. 179:1112-1116; and Appl. Environ. Microbiol. 67:688-695). The EDTA monooxygenase and NTA monooxygenase are highly homologous. EDTA monooxygenase can use both EDTA and NTA as substrates, but NTA monooxygenase can only use NTA as a substrate. Thus, we put our effort to isolate both NTA and EDTA degraders. In case, an anaerobic EDTA degrader is not immediately enriched, we will try to evolve the NTA degraders to use EDTA. Both aerobic and anaerobic enrichment cultures were set.

  16. Comparative Susceptibility of Anaerobic Bacteria to Minocycline, Doxycycline, and Tetracycline

    PubMed Central

    Chow, Anthony W.; Patten, Valerie; Guze, Lucien B.

    1975-01-01

    The comparative susceptibility of 622 recent clinical isolates of anaerobic bacteria to minocycline, doxycycline, and tetracycline was determined by an agar-dilution technique. In addition to Bacteroides fragilis, a variety of other anaerobic bacteria was resistant to achievable blood concentrations of tetracycline (55% inhibited by 6.25 μg/ml) and doxycycline (58% inhibited by 2.5 μg/ml). In contrast, minocycline was significantly more active (P < 0.05) than both doxycycline and tetracycline, and 70% of strains were inhibited by achievable blood concentrations of this antibiotic (2.5 μg/ml). The enhanced activity of minocycline was particularly striking for Peptococcus asaccharolyticus, P. magnus, P. prevotii, Peptostreptococcus anaerobius, and Bacteroides melaninogenicus. Further evaluation of the clinical efficacy of minocycline against anaerobic infections is indicated. PMID:1137358

  17. Acetate Metabolism in Anaerobes from the Domain Archaea

    PubMed Central

    Ferry, James G.

    2015-01-01

    Acetate and acetyl-CoA play fundamental roles in all of biology, including anaerobic prokaryotes from the domains Bacteria and Archaea, which compose an estimated quarter of all living protoplasm in Earth’s biosphere. Anaerobes from the domain Archaea contribute to the global carbon cycle by metabolizing acetate as a growth substrate or product. They are components of anaerobic microbial food chains converting complex organic matter to methane, and many fix CO2 into cell material via synthesis of acetyl-CoA. They are found in a diversity of ecological habitats ranging from the digestive tracts of insects to deep-sea hydrothermal vents, and synthesize a plethora of novel enzymes with biotechnological potential. Ecological investigations suggest that still more acetate-metabolizing species with novel properties await discovery. PMID:26068860

  18. Anaerobic orbital cellulitis: a clinical and experimental study.

    PubMed Central

    Jedrzynski, M S; Bullock, J D; McGuire, T W; Elder, B L; Bullock, J D

    1991-01-01

    In this article we have reviewed the clinical and bacteriologic aspects of anaerobic orbital cellulitis and have presented six patients to illustrate these points. Physicians who treat patients with orbital cellulitis should have a high index of suspicion for possible instances involving anaerobes, so that appropriate management can be started early. To investigate this problem further, we created an animal model of anaerobic orbital cellulitis. This model may be useful in future studies of the pathogenesis and treatment of this serious and often devastating disease. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 FIGURE 9 FIGURE 10 FIGURE 11 FIGURE 12 FIGURE 13 FIGURE 14 FIGURE 15 FIGURE 16 FIGURE 17 FIGURE 18 FIGURE 19 PMID:1808813

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

    NASA Astrophysics Data System (ADS)

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

    2003-12-01

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

  20. DEHALOGENATION: A NOVEL PATHWAY FOR THE ANAEROBIC BIODEGRADATION OF HALOAROMATIC COMPOUNDS

    EPA Science Inventory

    Microorganisms of lake sediment and sewage sludge anaerobically metabolize halobenzoates by a novel pathway. The primary degradative event was loss of the aryl halide without the alteration of the aromatic ring. Dehalogenation required strict anaerobic conditions and depended on ...

  1. Microbial degradation of lignin-derived compounds under anaerobic conditions

    SciTech Connect

    Colberg, P.J.

    1983-01-01

    Lignin is the second most abundant form of organic carbon in the biosphere. Recent laboratory studies indicate that a large fraction of polymeric lignin is incompletely degraded by aerobic lignolytic microorganisms and is subsequently released as lignin fragments of reduced molecular size. If such lignin-derived compounds become available in the anaerobic environment, they may serve as potential sources of organic carbon for organisms which release methane precursors. The methanogenic bacteria, in turn, serve as terminal members of the anaerobic food chain, and thus, limit the accumulation of organic carbon in anaerobic sinks. This thesis presents evidence to suggest that lignin-derived compounds which have molecular sizes greater than those of single-ring aromatic compounds (MW > 200) are anaerobically biodegradable to methane. This research involved development of selective enrichment cultures capable of utilizing oligolignols as sole carbon sources. Radiolabeled water-soluble catabolites, released during aerobic lignin degradation by the white rot fungus Phanerochaete chrysosporium, were subjected to anaerobic degradation. The second phase of work involved capillary gas chromatographic analyses of enrichment cultures fed a /sup 14/C-labeled, lignin-derived substrate of average molecular weight 600. 2-Bromoethanesulfonic acid was used to inhibit methane formation and enhance buildup of metabolic intermediates, resulting in the accumulation of volatile fatty acids, phenylacetate, benzoate, catechol, 3-phenyl-propionate, vanillin, syringic acid, vanillic acid, ferulic acid, and caffeic acid. A conceptual model for the anaerobic degradation of two- and three-ring lignin fragments is proposed which overlaps both the ferulate and benzoate degradation pathways at the level of single-ring aromatic compounds.

  2. C4-Dicarboxylate Utilization in Aerobic and Anaerobic Growth.

    PubMed

    Unden, Gottfried; Strecker, Alexander; Kleefeld, Alexandra; Kim, Ok Bin

    2016-06-01

    C4-dicarboxylates and the C4-dicarboxylic amino acid l-aspartate support aerobic and anaerobic growth of Escherichia coli and related bacteria. In aerobic growth, succinate, fumarate, D- and L-malate, L-aspartate, and L-tartrate are metabolized by the citric acid cycle and associated reactions. Because of the interruption of the citric acid cycle under anaerobic conditions, anaerobic metabolism of C4-dicarboxylates depends on fumarate reduction to succinate (fumarate respiration). In some related bacteria (e.g., Klebsiella), utilization of C4-dicarboxylates, such as tartrate, is independent of fumarate respiration and uses a Na+-dependent membrane-bound oxaloacetate decarboxylase. Uptake of the C4-dicarboxylates into the bacteria (and anaerobic export of succinate) is achieved under aerobic and anaerobic conditions by different sets of secondary transporters. Expression of the genes for C4-dicarboxylate metabolism is induced in the presence of external C4-dicarboxylates by the membrane-bound DcuS-DcuR two-component system. Noncommon C4-dicarboxylates like l-tartrate or D-malate are perceived by cytoplasmic one-component sensors/transcriptional regulators. This article describes the pathways of aerobic and anaerobic C4-dicarboxylate metabolism and their regulation. The citric acid cycle, fumarate respiration, and fumarate reductase are covered in other articles and discussed here only in the context of C4-dicarboxylate metabolism. Recent aspects of C4-dicarboxylate metabolism like transport, sensing, and regulation will be treated in more detail. This article is an updated version of an article published in 2004 in EcoSal Plus. The update includes new literature, but, in particular, the sections on the metabolism of noncommon C4-dicarboxylates and their regulation, on the DcuS-DcuR regulatory system, and on succinate production by engineered E. coli are largely revised or new. PMID:27415771

  3. Potential Application of Anaerobic Extremophiles for Hydrogen Production

    NASA Technical Reports Server (NTRS)

    Pikuta, Elena V.; Hoover, Richard B.

    2004-01-01

    During substrate fermentation many anaerobes produce the hydrogen as a waste product, which often regulates the growth of the cultures as an inhibitor. In nature the hydrogen is usually removed from the ecosystem due to its physical properties or by consumption of hydrogen by secondary anaerobes, which sometimes behave as competitors for electron donors as is seen in the classical example in anaerobic microbial communities via the interaction between methanogens and sulfate- or sulfur- reducers. It was demonstrated previously on mixed cultures of anaerobes at neutral pH that bacterial hydrogen production could provide an alternative energy source. But at neutral pH the original cultures can easily be contaminated by methanogens, a most unpleasant side effect of these conditions is the development of pathogenic bacteria. In both cases the rate of hydrogen production was dramatically decreased since some part of the hydrogen was transformed to methane, and the cultivation of human pathogens on a global scale is very dangerous. In our laboratory, experiments with obligately alkaliphilic bacteria that excrete hydrogen as the end metabolic product were performed at different temperature regimes. Mesophilic and moderately thermophilic bacterial cultures have been studied and compared for the most effective hydrogen production. For high-mineralized media with pH 9.5-10.0 not many methanogens are known to exist. Furthermore, the development of pathogenic contaminant microorganisms is virtually impossible: carbonate-saturated solutions are used as antiseptics in medicine. Therefore the cultivation of alkaliphilic hydrogen producing bacteria could be considered as most safe process for global Scale industry in future. Here we present experimental data on the rates of hydrogen productivity for mesophilic, alkaliphilic, obligately anaerobic bacterium Spirocheta americana ASpG1 and moderately thermophilic, alkaliphilic, facultative anaerobe Anoxybacillus pushchinoensis K1 and

  4. One step beyond a ribosome: The ancient anaerobic core.

    PubMed

    Sousa, Filipa L; Nelson-Sathi, Shijulal; Martin, William F

    2016-08-01

    Life arose in a world without oxygen and the first organisms were anaerobes. Here we investigate the gene repertoire of the prokaryote common ancestor, estimating which genes it contained and to which lineages of modern prokaryotes it was most similar in terms of gene content. Using a phylogenetic approach we found that among trees for all 8779 protein families shared between 134 archaea and 1847 bacterial genomes, only 1045 have sequences from at least two bacterial and two archaeal groups and retain the ancestral archaeal-bacterial split. Among those, the genes shared by anaerobes were identified as candidate genes for the prokaryote common ancestor, which lived in anaerobic environments. We find that these anaerobic prokaryote common ancestor genes are today most frequently distributed among methanogens and clostridia, strict anaerobes that live from low free energy changes near the thermodynamic limit of life. The anaerobic families encompass genes for bifunctional acetyl-CoA-synthase/CO-dehydrogenase, heterodisulfide reductase subunits C and A, ferredoxins, and several subunits of the Mrp-antiporter/hydrogenase family, in addition to numerous S-adenosyl methionine (SAM) dependent methyltransferases. The data indicate a major role for methyl groups in the metabolism of the prokaryote common ancestor. The data furthermore indicate that the prokaryote ancestor possessed a rotor stator ATP synthase, but lacked cytochromes and quinones as well as identifiable redox-dependent ion pumping complexes. The prokaryote ancestor did possess, however, an Mrp-type H(+)/Na(+) antiporter complex, capable of transducing geochemical pH gradients into biologically more stable Na(+)-gradients. The findings implicate a hydrothermal, autotrophic, and methyl-dependent origin of life. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi. PMID:27150504

  5. Microbial aggregates in anaerobic wastewater treatment.

    PubMed

    Kosaric, N; Blaszczyk, R

    1990-01-01

    The phenomenon aggregation of anaerobic bacteria gives an opportunity to speed up the digestion rate during methanogenesis. The aggregates are mainly composed of methanogenic bacteria which convert acetate and H2/CO2 into methane. Other bacteria are also included in the aggregates but their concentration is rather small. The aggregates may also be formed during acetogenesis or even hydrolysis but such aggregates are not stable and disrupt quickly when not fed. A two stage process seems to be suitable when high concentrated solid waste must be treated. Special conditions are necessary to promote aggregate formation from methanogenic bacteria but aggregates once formed are stable without feeding even for a few years. The structure, texture and activity of bacterial aggregates depend on several parameters: (1)--temperature and pH, (2)--wastewater composition and (3)--hydrodynamic conditions within the reactor. The common influence of all these parameters is still rather unknown but some recommendations may be given. Temperature and pH should be maintained in the range which is optimal for methanogenic bacteria e.g. a temperature between 32 and 50 degrees C and a value pH between 6.5 and 7.5. Wastewaters should contain soluble wastes and the specific loading rate should be around one kgCOD(kgVSS)-1 d-1. The concentration of the elements influences aggregate composition and probably structure and texture. At high calcium concentration a change in the colour of the granules has been observed. Research is necessary to investigate the influence of other elements and organic toxicants on maintenance of the aggregates. Hydrodynamic conditions seem to influence the stability of the granules over long time periods. At low liquid stream rates, aggregates may starve and lysis within the aggregates is possible which results in hollowing of aggregates and their floating. At high liquid stream rates the aggregates may be disrupted and washed out of the reactor as a flocculent

  6. Thermophilic anaerobic digestion of industrial orange waste.

    PubMed

    Kaparaju, P L N; Rintala, J A

    2006-06-01

    Thermophilic anaerobic digestion of industrial orange waste (pulp and peel) with subsequent aerobic post-treatment of the digestate was evaluated. Methane production potential was first determined in batch assays and the effects of operational parameters such as hydraulic retention times (HRT) and organic loading rates (OLR) on process performance were studied through semi-continuous digestion. In batch assays, methane production potential of about 0.49 m(3) kg(-1) volatile solids (VS)(added waste) was achieved. In semi-continuous digestion, loading at 2.8 kgVS m(-3) d(-1) (2.9 kg total solids (TS) m(-3) d(-1)) and HRT of 26 d produced specific methane yields of 0.6 m(3) kg(-1) VS (added waste) (0.63 m(3) kg(-1) VS(added waste)). Operating at a higher OLR of 4.2 kgVS m(-3) d(-1) (4.4 kg TS m(-3) d(-1)) and 40 d HRT produced 0.5 m(3) of methane kg(-1) VS (added waste) (0.63-0.52 m(3) kg(-1) TS (added waste). Up to 70% of TS of industrial orange waste (11.6% TS) was methanised. Further increase in OLR to 5.6 kg VS m(-3) d(-1) (5.9 kg TS m(-3) d(-1); HRT of 20 d) resulted in an unstable and non-functional digester process shown directly through complete cessation of methanogenesis, drop in methane content, reduced pH and increase in volatile fatty acid (VFA) concentrations, especially acetate and soluble chemical oxygen demand. A pH adjustment (from an initial 3.2 to ca. 8) for the low pH orange waste was necessary and was found to be a crucial factor for stable digester operation as the process showed a tendency to be inhibited due to accumulation of VFAs and decrease in digester pH. Aerobic post-treatment of digestate resulted in removal of ammonia and VFAs. PMID:16865918

  7. Improved anaerobic digestion by staged fermentation and advanced reactor design

    SciTech Connect

    Ghosh, S.; Bostian, H.E.; Henry, M.P.; Sajjad, A.; Farrell, J.B.; Salotto, B.V.

    1985-01-01

    The anaerobic digestion process has taken on new importance and emphasis in recent years because of its potential applications for energy and chemicals production from various types of renewable-carbon resources, and because it can be coupled with certain electrochemical, thermochemical, and biochemical processes to generate electric power, hydrocarbons, methanol, and other high-value products. A number of initiatives have been taken to improve the anaerobic digestion process in keeping with the increasing appreciation for its utility and versatility of application in municipal, industrial, and rural settings.

  8. Relative recovery of anaerobes on different isolation media.

    PubMed Central

    Sondag, J E; Ali, M; Murray, P R

    1979-01-01

    The recovery of clinical anaerobic isolates on selective and nonselective agar media, as well as the time required to detect the isolates, was examined. Of a total of 235 isolates, 77, 46, and 40% were detected on Schaedler blood agar, colistinnalidixic acid blood agar, and kanamycin-vancomycin-lysed blood agar, respectively, and 94% were detected on the combination of Schaedler blood agar with kanamycin-vancomycin-lysed blood agar. A total of 19% of the anaerobes were detected after incubation for 1 day, and 70% were detected after 2 days. PMID:544636

  9. Anaerobic oxidation of acetylene by estuarine sediments and enrichment cultures

    USGS Publications Warehouse

    Culbertson, Charles W.; Zehnder, Alexander J. B.; Oremland, Ronald S.

    1981-01-01

    Acetylene disappeared from the gas phase of anaerobically incubated estuarine sediment slurries, and loss was accompanied by increased levels of carbon dioxide. Acetylene loss was inhibited by chloramphenicol, air, and autoclaving. Addition of 14C2H2 to slurries resulted in the formation of 14CO2 and the transient appearance of 14C-soluble intermediates, of which acetate was a major component. Acetylene oxidation stimulated sulfate reduction; however, sulfate reduction was not required for the loss of C2H2 to occur. Enrichment cultures were obtained which grew anaerobically at the expense of C2H2.

  10. Detoxifying CO2 capture reclaimer waste by anaerobic digestion.

    PubMed

    Wang, Shuai; Hovland, Jon; Brooks, Steven; Bakke, Rune

    2014-01-01

    The decrease in toxicity of carbon capture reclaimer monoethanolamine (MEA) waste (MEAw) during anaerobic degradation of such waste together with easily degradable organics was investigated. Samples were collected from a bioreactor at steady state with 86 % organic chemical oxygen demand removal at room temperature, which had been running on MEAw for 2 years. The toxicity of the digester effluents were 126, 42 and 10 times lower than that of the MEAw to the tested freshwater trophic groups of Pseudokirchneriella subcapitata, Daphnia magna and embryos of Danio rerio, respectively. The toxicity of the tested taxonomic groups after anaerobic digestion was mainly attributed to the ammonia generated by the degradation of MEAw. PMID:24122630

  11. Anaerobic degradation of phenanthrene and pyrene in mangrove sediment.

    PubMed

    Chang, Bea-Ven; Chang, I T; Yuan, S Y

    2008-02-01

    This study investigated the anaerobic degradation of the polycyclic aromatic hydrocarbons (PAHs) phenanthrene and pyrene in mangrove sediment from Taiwan. The anaerobic degradation of PAH was enhanced by the addition of acetate, lactate, pyruvate, sodium chloride, cellulose, or zero-valent iron. However, it was inhibited by the addition of humic acid, di-(2-ethylhexyl) phthalate (DEHP), nonylphenol, or heavy metals. Of the microorganism strains isolated from the sediment samples, we found that strain MSA3 (Clostridium pascui), expressed the best ability to biodegrade PAH. The inoculation of sediment with the strain MSA3 could enhance PAH degradation. PMID:18188486

  12. Biogas production from anaerobic digestion of Spirulina maxima algal biomass

    SciTech Connect

    Rejean Samson; Anh LeDuy

    1982-08-01

    Spirulina maxima algal biomass could be used as the sole nutrient for the production of biogas by anaerobic digestion process. It is relatively simple to adapt the municipal sewage sludge to this new substrate. The adapted sludge is very stable. Under nonoptimal conditions, the methane yield and productivity obtained were 0.26 m/sup 3//(kg VS added day) and 0.26 m/sup 3//(kg VS added day), respectively, with the semicontinuous, daily fed, anaerobic digestion having loading rate of 0.97 kg VS/(m/sup 3/ day), retention time of 33 days and temperature of 30/sup 0/C.

  13. Anaerobic methanotrophy in tidal wetland: Effects of electron acceptors

    NASA Astrophysics Data System (ADS)

    Lin, Li-Hung; Yu, Zih-Huei; Wang, Pei-Ling

    2016-04-01

    Wetlands have been considered to represent the largest natural source of methane emission, contributing substantially to intensify greenhouse effect. Despite in situ methanogenesis fueled by organic degradation, methanotrophy also plays a vital role in controlling the exact quantity of methane release across the air-sediment interface. As wetlands constantly experience various disturbances of anthropogenic activities, biological burrowing, tidal inundation, and plant development, rapid elemental turnover would enable various electron acceptors available for anaerobic methanotrophy. The effects of electron acceptors on stimulating anaerobic methanotrophy and the population compositions involved in carbon transformation in wetland sediments are poorly explored. In this study, sediments recovered from tidally influenced, mangrove covered wetland in northern Taiwan were incubated under the static conditions to investigate whether anaerobic methanotrophy could be stimulated by the presence of individual electron acceptors. Our results demonstrated that anaerobic methanotrophy was clearly stimulated in incubations amended with no electron acceptor, sulfate, or Fe-oxyhydroxide. No apparent methane consumption was observed in incubations with nitrate, citrate, fumarate or Mn-oxides. Anaerobic methanotrophy in incubations with no exogenous electron acceptor appears to proceed at the greatest rates, being sequentially followed by incubations with sulfate and Fe-oxyhydroxide. The presence of basal salt solution stimulated methane oxidation by a factor of 2 to 3. In addition to the direct impact of electron acceptor and basal salts, incubations with sediments retrieved from low tide period yielded a lower rate of methane oxidation than from high tide period. Overall, this study demonstrates that anaerobic methanotrophy in wetland sediments could proceed under various treatments of electron acceptors. Low sulfate content is not a critical factor in inhibiting methane

  14. Methanogenic Community Dynamics during Anaerobic Utilization of Agricultural Wastes.

    PubMed

    Ziganshin, A M; Ziganshina, E E; Kleinsteuber, S; Pröter, J; Ilinskaya, O N

    2012-10-01

    This work is devoted to the investigation of the methanogenic archaea involved in anaerobic digestion of cattle manure and maize straw on the basis of terminal restriction fragment length polymorphism (T-RFLP) analysis of archaeal 16S rRNA genes. The biological diversity and dynamics of methanogenic communities leading to anaerobic degradation of agricultural organic wastes with biogas production were evaluated in laboratory-scale digesters. T-RFLP analysis, along with the establishment of archaeal 16S rRNA gene clone libraries, showed that the methanogenic consortium consisted mainly of members of the generaMethanosarcinaandMethanoculleus,with a predominance ofMethanosarcinaspp. throughout the experiment. PMID:23346384

  15. Engineered microorganisms capable of producing target compounds under anaerobic conditions

    DOEpatents

    Buelter, Thomas; Meinhold, Peter; Feldman, Reid M. Renny; Hawkins, Andrew C.; Urano, Jun; Bastian, Sabine; Arnold, Frances

    2012-01-17

    The present invention is generally provides recombinant microorganisms comprising engineered metabolic pathways capable of producing C3-C5 alcohols under aerobic and anaerobic conditions. The invention further provides ketol-acid reductoisomerase enzymes which have been mutated or modified to increase their NADH-dependent activity or to switch the cofactor preference from NADPH to NADH and are expressed in the modified microorganisms. In addition, the invention provides isobutyraldehyde dehydrogenase enzymes expressed in modified microorganisms. Also provided are methods of producing beneficial metabolites under aerobic and anaerobic conditions by contacting a suitable substrate with the modified microorganisms of the present invention.

  16. Treatment of artificial soybean wastewater anaerobic effluent in a continuous aerobic-anaerobic coupled (CAAC) process with excess sludge reduction.

    PubMed

    Wang, Jun; Li, Xiaoxia; Fu, Weichao; Wu, Shihan; Li, Chun

    2012-12-01

    In this study, treatment of artificial soybean wastewater anaerobic effluent was studied in a continuous aerobic-anaerobic coupled (CAAC) process. The focus was on COD and nitrogen removal as well as excess sludge reduction. During the continuous operation without reflux, the COD removal efficiency was 96.5% at the optimal hydraulic retention time (HRT) 1.3 days. When HRT was shortened to 1.0 day, reflux from anaerobic zone to moving bed biofilm reactor (MBBR) was introduced. The removal efficiencies of COD and TN were 94.4% and 76.0% at the optimal reflux ratio 30%, respectively. The sludge yield coefficient of CAAC was 0.1738, the simultaneous removal of COD and nitrogen with in situ sludge reduction could be achieved in this CAAC process. The sludge reduction mechanism was discussed by soluble components variation along the water flow. PMID:23073101

  17. Anaerobic Biotransformation and Mobility of Pu and Pu-EDTA

    SciTech Connect

    Bolton, H., Jr.; Bailey, V.L.; Plymale, A.E.; Rai, D.; Xun, L.

    2006-04-05

    The complexation of radionuclides (e.g., plutonium (Pu) and {sup 60}Co) by co-disposed ethylenediaminetetraacetate (EDTA) has enhanced their transport in sediments at DOE sites. Pu(IV)-EDTA is not stable in the presence of relatively soluble Fe(III) compounds. Since most DOE sites have Fe(III) containing sediments, Pu(IV) is likely not the mobile form of Pu-EDTA. The only other Pu-EDTA complex stable in groundwater relevant to DOE sites would be Pu(III)-EDTA, which only forms under anaerobic conditions. Research is therefore needed to investigate the biotransformation of Pu and Pu-EDTA under anaerobic conditions and the anaerobic biodegradation of Pu-EDTA. The biotransformation of Pu and Pu-EDTA under various anaerobic regimes is poorly understood including the reduction kinetics of Pu(IV) to Pu(III) from soluble (Pu(IV)-EDTA) and insoluble Pu(IV), the redox conditions required for this reduction, the strength of the Pu(III)-EDTA, how the Pu(III)-EDTA competes with other dominant anoxic soluble metals (e.g., Fe(II)), and the oxidation kinetics of Pu(III)-EDTA. Finally, soluble Pu(III)-EDTA under anaerobic conditions would require anaerobic degradation of the EDTA to limit Pu(III) transport. Anaerobic EDTA degrading microorganisms have never been isolated. Recent results have shown that Shewanella oneidensis MR-1, a dissimilatory metal reducing bacterium, can reduce Pu(IV) to Pu(III). The Pu(IV) was provided as insoluble PuO2. The highest rate of Pu(IV) reduction was with the addition of AQDS, an electron shuttle. Of the total amount of Pu solubilized (i.e., soluble through a 0.36 nm filter), approximately 70% was Pu(III). The amount of soluble Pu was between 4.8 and 3.2 micromolar at day 1 and 6, respectively, indicating rapid reduction. The micromolar Pu is significant since the drinking water limit for Pu is 10{sup -12} M. On-going experiments are investigating the influence of EDTA on the rate of Pu reduction and the stability of the formed Pu(III). We have also

  18. Comparison of digestate from solid anaerobic digesters and dewatered effluent from liquid anaerobic digesters as inocula for solid state anaerobic digestion of yard trimmings.

    PubMed

    Xu, Fuqing; Wang, Feng; Lin, Long; Li, Yebo

    2016-01-01

    To select a proper inoculum for the solid state anaerobic digestion (SS-AD) of yard trimmings, digestate from solid anaerobic digesters and dewatered effluent from liquid anaerobic digesters were compared at substrate-to-inoculum (S/I) ratios from 0.2 to 2 (dry basis), and total solids (TS) contents from 20% to 35%. The highest methane yield of around 244L/kg VSfeed was obtained at an S/I ratio of 0.2 and TS content of 20% for both types of inoculum. The highest volumetric methane productivity was obtained with dewatered effluent at an S/I ratio of 0.6 and TS content of 24%. The two types of inoculum were found comparable regarding methane yields and volumetric methane productivities at each S/I ratio, while using dewatered effluent as inoculum reduced the startup time. An S/I ratio of 1 was determined to be a critical level and should be set as the upper limit for mesophilic SS-AD of yard trimmings. PMID:26575617

  19. Anaerobic Soil Disinfestation For Florida Specialty Crop Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic soil disinfestation (ASD) is a process in which organic amendments are applied to soil, covered with a polyethylene film, and saturated with water to create conditions conducive for soil bacteria to deplete oxygen levels and generate organic acids in soil. The generation of acids and re...

  20. Anaerobic digestion of the liquid fraction of dairy manure

    SciTech Connect

    Haugen, V.; Dahlberg, S.; Lindley, J.A.

    1983-06-01

    The authors tested several solid liquid separation systems suitable for processing dairy manure prior to anaerobic digestion. None of the systems tried have completely satisfied the requirements. Evaluated effects of separation on biogas production. Unseparated dairy manure produced more biogas than the liquid fraction.

  1. Fate of 17B-estradiol in anaerobic lagoon digesters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fate of [14C]17B-estradiol ([14C]E2) was monitored for 42 d in triplicate 10 L anaerobic digesters. Total radioactive residues (TRR) decreased rapidly in the liquid layer of the digesters and reached a steady-state value of 19-24% of the initial dose after 4 days. LC/MS/MS analyses of the liqu...

  2. POLISHING EFFLUENT FROM A PERCHLORATE-REDUCING ANAEROBIC BIOLOGICAL CONTACTOR

    EPA Science Inventory

    The U.S. Environmental Protection Agency undertook at 3 ½ year pilot-scale biological perchlorate treatment study that included two long (311 and 340 days) examinations of anaerobic effluent polishing. The polishing system consisted of hydrogen peroxide addition and aeration, fo...

  3. Anaerobic growth of Corynebacterium glutamicum via mixed-acid fermentation.

    PubMed

    Michel, Andrea; Koch-Koerfges, Abigail; Krumbach, Karin; Brocker, Melanie; Bott, Michael

    2015-11-01

    Corynebacterium glutamicum, a model organism in microbial biotechnology, is known to metabolize glucose under oxygen-deprived conditions to l-lactate, succinate, and acetate without significant growth. This property is exploited for efficient production of lactate and succinate. Our detailed analysis revealed that marginal growth takes place under anaerobic conditions with glucose, fructose, sucrose, or ribose as a carbon and energy source but not with gluconate, pyruvate, lactate, propionate, or acetate. Supplementation of glucose minimal medium with tryptone strongly enhanced growth up to a final optical density at 600 nm (OD600) of 12, whereas tryptone alone did not allow growth. Amino acids with a high ATP demand for biosynthesis and amino acids of the glutamate family were particularly important for growth stimulation, indicating ATP limitation and a restricted carbon flux into the oxidative tricarboxylic acid cycle toward 2-oxoglutarate. Anaerobic cultivation in a bioreactor with constant nitrogen flushing disclosed that CO2 is required to achieve maximal growth and that the pH tolerance is reduced compared to that under aerobic conditions, reflecting a decreased capability for pH homeostasis. Continued growth under anaerobic conditions indicated the absence of an oxygen-requiring reaction that is essential for biomass formation. The results provide an improved understanding of the physiology of C. glutamicum under anaerobic conditions. PMID:26276118

  4. Biogas energy production from tropical biomass wastes by anaerobic digestion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic digestion (AD) is an attractive technology in tropical regions for converting locally abundant biomass wastes into biogas which can be used to produce heat, electricity, and transportation fuels. However, investigations on AD of tropical forestry wastes, such as albizia biomass, and food w...

  5. Fate of estradiol and testosterone in anaerobic lagoon digestors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory-scale lagoon digestors were constructed, and the fate of 14C-labelled 17ß-estradiol (E2) and testosterone (Test) were monitored for 42 d anaerobically under biological and sterile conditions. Hormone levels decreased in the liquid layer and increased in the sludge with time. At 42 d, 16-2...

  6. PARAFFIN CONTROL IN OIL WELLS USING ANAEROBIC MICROORGANISMS

    EPA Science Inventory

    Enrichment and monitoring of the above-described cultures for the ability to degrade waxy paraffins under anaerobic conditions will continue. Experiments will be conducted to determine the nutritional requirements of some of the enrichment cultures to improve growth and deduce...

  7. Assessment of hydrogen metabolism in commercial anaerobic digesters.

    PubMed

    Kern, Tobias; Theiss, Juliane; Röske, Kerstin; Rother, Michael

    2016-05-01

    Degradation of biomass in the absence of exogenous electron acceptors via anaerobic digestion involves a syntrophic association of a plethora of anaerobic microorganisms. The commercial application of this process is the large-scale production of biogas from renewable feedstock as an alternative to fossil fuels. After hydrolysis of polymers, monomers are fermented to short-chain fatty acids and alcohols, which are further oxidized to acetate. Carbon dioxide, molecular hydrogen (H2), and acetate generated during the process are converted to methane by methanogenic archaea. Since many of the metabolic pathways as well as the syntrophic interactions and dependencies during anaerobic digestion involve formation, utilization, or transfer of H2, its metabolism and the methanogenic population were assessed in various samples from three commercial biogas plants. Addition of H2 significantly increased the rate of methane formation, which suggested that hydrogenotrophic methanogenesis is not a rate-limiting step during biogas formation. Methanoculleus and Methanosarcina appeared to numerically dominate the archaeal population of the three digesters, but their proportion and the Bacteria-to-Archaea ratio did not correlate with the methane productivity. Instead, hydrogenase activity in cell-free extracts from digester sludge correlated with methane productivity in a positive fashion. Since most microorganisms involved in biogas formation contain this activity, it approximates the overall anaerobic metabolic activity and may, thus, be suitable for monitoring biogas reactor performance. PMID:26995607

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

    PubMed

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

    2012-04-30

    Polybrominated diphenyl ethers (PBDEs) are widely used flame retardant additives for many plastic and electronic products. Owing to their ubiquitous distribution in the environment, multiple toxicity to humans, and increasing accumulation in the environment, the fate of PBDEs is of serious concern for public safety. In this study, the degradation of 4-monobrominated diphenyl ether (BDE-3) in anaerobic sludge and the effect of carbon source addition were investigated. BDE-3 can be degraded by two different anaerobic sludge samples. The by-products, diphenyl ether (DE) and bromide ions, were monitored, indicating the reaction of debromination within these anaerobic samples. Co-metabolism with glucose facilitated BDE-3 biodegradation in terms of kinetics and efficiency in the Jhongsing sludge. Through the pattern of amplified 16S rRNA gene fragments in denatured gradient gel electrophoresis (DGGE), the composition of the microbial community was analyzed. Most of the predominant microbes were novel species. The fragments enriched in BDE-3-degrading anaerobic sludge samples are presumably Clostridium sp. This enrichment coincides with the H(2) gas generation and the facilitation of debromination during the degradation process. Findings of this study provide better understanding of the biodegradation of brominated DEs and can facilitate the prediction of the fate of PBDEs in the environment. PMID:22370205

  9. ASSESSING TOXICITY OF ORGANIC CHEMICALS TO ANAEROBIC TREATMENT PROCESSES

    EPA Science Inventory

    A screening protocol has been developed to provide a rapid but dependable and repeatable assessment of the effect of toxic organic chemicals on anaerobic treatment processes. his protocol provides information on the rate limiting biological reactions and the concentration of toxi...

  10. INCREASE OF INDICATOR ORGANISMS FOLLOWING ANAEROBIC DIGESTION AND CENTRIFUGE DEWATERING.

    EPA Science Inventory

    The Water Environment Research Foundation (WERF) recently published a report titled “Examination of Reactivation and Regrowth of Fecal Coliforms in Anaerobically Digested Sludges”. Seven full-scale publicly owned treatment facilities were sampled several times to determine if bac...

  11. Pulse power enhancement of the anaerobic digester process

    SciTech Connect

    Greene, H.W.

    1996-12-31

    A pilot study of the effects of Pulse Power Processing on an anaerobic digester system was completed at the Decatur Utilities Dry Creek Wastewater Treatment Plant, in Decatur Alabama, in September, 1995. This patented method generates several significant effects when all biosolids material is treated as it enters the anaerobic system. Intense, high peak-power plasma arcs are created, one at each end of the parabolic processing chamber, to produce an amplified synergy of alterations to the digester sludge flowing between them. The millisecond electric discharges generate localized temperatures as high as 30,000 K{degrees}, followed by a rapid cooling of the flowing liquid, which produces acoustic shock waves with pressures approaching 5,000 atmospheres. This destructive force: ruptures many of the cell walls of the bacteria and other single-cell organisms, releasing their vacuole fluids; breaks carbon bonds to form smaller organic compounds; and pulverizes large particle conglomerates, increasing the overall surface area of the solids. These beneficial results serve to boost the nutrient source for the anaerobes in the digester. In conjunction with LTV radiation, the formation of excited chemical radicals (including OH{sup -}), and the changes in ionic charge through alteration of the zeta potential, the bioreactor system is turbocharged to enhance the conversion of volatile biosolids to methane gas, which is the natural respiratory by-product of anaerobic digestion.

  12. Texture-dependent anaerobic microsites constrain soil carbon oxidation rates

    NASA Astrophysics Data System (ADS)

    Keiluweit, Marco; Fendorf, Scott

    2016-04-01

    Soil texture, which is a product of parent material, climate and other soil forming factors, is a predictor for long-term storage of soil organic carbon (SOC) storage in many soil ecosystems. Positive correlation between texture (particularly clay content) and SOC storage have long been attributed to protective associations between clay minerals and organic compounds that prevent microbial and enzymatic access - a mechanism commonly referred to as 'mineral protection'. Texture therefore acts as the primary proxy for mineral protection in terrestrial ecosystem models used to assess SOC storage and its sensitivity to global change impacts. Here we show that this protective effect of texture is not only due to mineral protection, but also to the formation of anaerobic microsites. Combining micro-scale laboratory experiments with field-scale observations, we find that oxygen diffusion limitations within clay-rich domains create anaerobic microsites within seemingly well-aerated soils, shifting microbial metabolism to less efficient anaerobic SOC oxidation pathways. Kinetic and thermodynamic constraints reduce SOC oxidation rates within these anaerobic microsites by an order of magnitude relative to aerobic rates, and caused the preservation of bioavailable, polymeric and reduced organic compounds. Lifting these metabolic constraints through increased soil aeration (e.g., through changes in precipitation patterns or land use) may stimulate microbial oxidation of this inherently bioavailable SOC pool. Models that attribute the effects of texture merely to 'mineral protection' may therefore underestimate the vulnerability of soil C to global change impacts.

  13. The role of anaerobic digestion in the emerging energy economy.

    PubMed

    Batstone, Damien John; Virdis, Bernardino

    2014-06-01

    Anaerobic digestion is the default process for biological conversion of residue organics to renewable energy and biofuel in the form of methane. However, its scope of application is expanding, due to availability of new technologies, and the emerging drivers of energy and nutrient conservation and recovery. Here, we outline two of these new application areas, namely wastewater nutrient and energy recovery, and generation of value added chemicals through mixed culture biotechnology. There exist two options for nutrient and energy recovery from domestic wastewater: low energy mainline and partition-release-recovery. Both are heavily dependent on anaerobic digestion as an energy generating and nutrient release step, and have been enabled by new technologies such as low emission anaerobic membrane processes. The area of mixed culture biotechnology has been previously identified as a key industrial opportunity, but is now moving closer to application due application of existing and new technologies. As well as acting as a core technology option in bioproduction, anaerobic digestion has a key role in residual waste valorization and generation of energy for downstream processing. These new application areas and technologies are emerging simultaneously with substantial advances in knowledge of underlying mechanisms such as electron transfer, understanding of which is critical to development of the new application areas. PMID:24534620

  14. Anaerobic digestion: Principles and practices for biogas systems

    SciTech Connect

    Gunnerson, C.G.; Stuckey, D.C.; Greeley, M.; Skrinde, R.T.

    1986-01-01

    This report, one in a continuing subseries on ''integrated resource recovery,'' explores the history, technology, and applications of anaerobic digestion, the biological process by which organic materials are degraded in the absence of oxygen to produce a combustible gas, methane, and carbon dioxide.

  15. Anaerobic microbial dissolution of lead and production of organic acids

    SciTech Connect

    Francis, A.J.; Dodge, C.; Chendrayan, K.; Quinby, H.L.

    1988-07-19

    A method of solubilizing lead oxide in industrial wastes and producing soluble Pb/sup 2+/ which is described comprises dissolving the lead oxide by contacting the wastes with an anaerobic bacterial culture containing Clostridium sp. ATCC No. 53464 before the wastes are dumped into the environment, and removing the solubilized lead from the wastes by chemical separation and bioaccumulation.

  16. Anaerobic Biotransformation and Mobility of Pu and PuEDTA

    SciTech Connect

    Xun, Luying

    2005-06-01

    The objective of this report is to isolate anaerobic EDTA-degrading bacteria. Although our goal is to isolate anaerobic EDTA degraders, we initiated the experiments to include nitrilotriacetate (NTA), which is a structure homologue of EDTA. All the aerobic EDTA degraders can degrade NTA, but the isolated NTA degraders cannot degrade EDTA. Since NTA is a simpler structure homologue, it is likely that EDTA-degrading ability is evolved from NTA degradation. This hypothesis is further supported from our characterization of EDTA and NTA-degrading enzymes and genes (J. Bact. 179:1112-1116; and Appl. Environ. Microbiol. 67:688-695). The EDTA monooxygenase and NTA monooxygenase are highly homologous. EDTA monooxygenase can use both EDTA and NTA as substrates, but NTA monooxygenase can only use NTA as a substrate. Thus, we put our effort to isolate both NTA and EDTA degraders. In case, an anaerobic EDTA degrader is not immediately enriched, we will try to evolve the NTA degraders to use EDTA. Both aerobic and anaerobic enrichment cultures were set.

  17. Inactivation of dairy manure-borne pathogens by anaerobic digestion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Anaerobic digestion of animal manure has the potential to inactivate enteric pathogens, thereby reducing exposures to livestock and humans when the products of digestion are disposed by land-spreading or irrigation or returned to livestock uses such as bedding. Data on digester effectiv...

  18. EVALUATION OF ANAEROBIC EXPANDED BED REACTOR FOR SEWAGE TREATMENT

    EPA Science Inventory

    Bench scale anaerobic expanded bed reactors were operated at the U.S. EPA Test and Evaluation Facility to determine the effect of relative concentrations between organics and sulfate on the organics removal. The bench scale results showed that less organics were removed as the su...

  19. Aerobic Capacity and Anaerobic Power Levels of the University Students

    ERIC Educational Resources Information Center

    Taskin, Cengiz

    2016-01-01

    The aim of study was to analyze aerobic capacity and anaerobic power levels of the university students. Total forty university students who is department physical education and department business (age means; 21.15±1.46 years for male and age means; 20.55±1.79 years for female in department physical education), volunteered to participate in this…

  20. ANAEROBIC COMPOST CONSTRUCTED WETLANDS SYSTEM TECHNOLOGY - SITE ITER

    EPA Science Inventory

    In Fall 1994, anaerobic compost wetlands in both upflow and downflow configurations were constructed adjacent to and received drainage from the Burleigh Tunnel, which forms part of the Clear Creek/Central City Superfund site. The systems were operated over a 3 year period. The e...

  1. ANAEROBIC COMPOST CONSTRUCTED WETLANDS SYSTEM TECHNOLOGY - SITE TECHNOLOGY CAPSULE

    EPA Science Inventory

    In fall 1994, anaerobic compost wetlands in both upflow and down flow configurations were constructed adjacent to and received drainage from the Burleigh tunnel, which forms part of the Clear Creek/Central City Superfund site. The systems were operated over a 3 year period. The ...

  2. Effect of anaerobic soil disinfestation on weed seed germination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The project goal is to optimize anaerobic soil disinfestation (ASD) as an alternative to methyl bromide fumigation using strawberry in coastal California and pepper/eggplant double crop in southeast Florida as model systems (Shennan et al., 2007). In preparation for field experiments, a series of po...

  3. EFFECT OF BTEX AND ETHANOL ON ANAEROBIC BIOTRANSFORMATION OF MTBE

    EPA Science Inventory

    We have recently demonstrated that natural anaerobic biotransformation of MTBE to TBA can account for the natural attenuation of MTBE in a plume from a gasoline spill at Parsippany, New Jersey. It is well established in the literature that the presence of the BTEX compounds natu...

  4. Treatment of phthalic waste by anaerobic hybrid reactor

    SciTech Connect

    Tur, M.Y.; Huang, J.C.

    1997-11-01

    The anaerobic treatment performance of phthalic acid at 4,000 mg/L (dry weight) by a hybrid reactor consisting of an upflow anaerobic sludge blanket (UASB) and a biofilter was examined. Using anaerobic sewage sludge as the seed and glucose as a carbon supplement, it took 3 months to initiate phthalate degradation. After that, the glucose supplement could be discontinued. At 35 C and a phthalic loading of 20 g-COD/L-d, the chemical oxygen demand (COD) removal efficiency was nearly 95%. About 89.5% of the removed phthalic COD was converted to methane. When the phthalic loadings were increased to 26.7, 33.0, 39.7, and 46.3 g-COD/L-d, the COD removal efficiencies were progressively reduced to 78, 65, 58, and 47.7%, respectively. More than 95% of the residual effluent COD was composed of nondecomposed phthalic acid. In the hybrid reactor, 86% of the biomass was found in the UASB section while the remaining 14% was found in the biofilter section. The anaerobic sludge could lead to granulation. At 35 C and a phthalic loading of 26 g-COD/L-D, the overall specific removal rate was 0.81--0.85 g-COD/g VSS-d, and the corresponding methane production rate was 0.24--0.26 L CH{sub 4}/g VSS-d.

  5. Anaerobic Growth of Corynebacterium glutamicum via Mixed-Acid Fermentation

    PubMed Central

    Michel, Andrea; Koch-Koerfges, Abigail; Krumbach, Karin; Brocker, Melanie

    2015-01-01

    Corynebacterium glutamicum, a model organism in microbial biotechnology, is known to metabolize glucose under oxygen-deprived conditions to l-lactate, succinate, and acetate without significant growth. This property is exploited for efficient production of lactate and succinate. Our detailed analysis revealed that marginal growth takes place under anaerobic conditions with glucose, fructose, sucrose, or ribose as a carbon and energy source but not with gluconate, pyruvate, lactate, propionate, or acetate. Supplementation of glucose minimal medium with tryptone strongly enhanced growth up to a final optical density at 600 nm (OD600) of 12, whereas tryptone alone did not allow growth. Amino acids with a high ATP demand for biosynthesis and amino acids of the glutamate family were particularly important for growth stimulation, indicating ATP limitation and a restricted carbon flux into the oxidative tricarboxylic acid cycle toward 2-oxoglutarate. Anaerobic cultivation in a bioreactor with constant nitrogen flushing disclosed that CO2 is required to achieve maximal growth and that the pH tolerance is reduced compared to that under aerobic conditions, reflecting a decreased capability for pH homeostasis. Continued growth under anaerobic conditions indicated the absence of an oxygen-requiring reaction that is essential for biomass formation. The results provide an improved understanding of the physiology of C. glutamicum under anaerobic conditions. PMID:26276118

  6. Anaerobic Digestion. Instructor's Guide. Biological Treatment Process Control.

    ERIC Educational Resources Information Center

    Carnegie, John W., Ed.

    This instructor's guide contains materials needed to teach a four-lesson unit on anaerobic digestion control. These materials include: (1) unit overview; (2) lesson plans; (3) lecture outlines; (4) student worksheets for each lesson (with answers); and (5) two copies of a final quiz (with and without answers). Lesson 1 is a review of the theory of…

  7. Anaerobic Digestion Analysis. Training Module 5.120.2.77.

    ERIC Educational Resources Information Center

    Kirkwood Community Coll., Cedar Rapids, IA.

    This document is an instructional module package prepared in objective form for use by an instructor familiar with alkalinity, volatile acids and carbon dioxide determinations for an anaerobic sludge digester. Included are objectives, instructor guides, student handouts and transparency masters. This module considers total and bicarbonate…

  8. Degradation potential and growth of anaerobic bacteria in produced water.

    PubMed

    Vieira, D S; Sérvulo, E F C; Cammarota, M C

    2005-08-01

    The efficiency of an anaerobic biological treatment for the reduction of essential contaminants of produced water from an offshore oilfield was investigated using a microbial consortium enriched with sulphate-reducing bacteria (SRB). Experiments were conducted in a bench bioreactor at 35 degrees C, 250 rpm, with intermittent purges of N2 gas in order to establish anaerobic conditions and to remove the H2S generated. The results showed that pH control effectively influenced the activity of the anaerobic bacteria leading to COD removal of 57%. Meanwhile, pH control was found to have no influence on the removal efficiencies of oil and grease and total phenols. In all experiments, removals of oil and grease and total phenols of 60% and 58-67%, respectively, were obtained after a 15-day process. In studies carried out with biomass reuse the reductions obtained were 61% for oil and grease and 78% for total phenols over the same period. Such results point to the technical feasibility of anaerobic biodegradation for oilfield wastewater treatment. PMID:16128390

  9. A STUDY OF LAND APPLICATION OF ANAEROBICALLY DIGESTED BIOSOLIDS

    EPA Science Inventory

    A field-scale research project was conducted in 2004-2005 to evaluate land application of anaerobically digested biosolids at agronomic levels. Biosolids had not been applied to this land previously. For this study, biosolids wee applied in a 100-m diameter circle by a side dis...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  11. PILOT-SCALE ANAEROBIC FILTER TREATMENT OF HEAT TREATMENT LIQUOR

    EPA Science Inventory

    This investigation was undertaken to demonstrate the application of the anaerobic filter in the treatment of liquor waste resulting from heat treatment of raw sludge in municipal sewage treatment plants. The liquor which contains high concentrations of soluble wastes is often ret...

  12. CONTROL OF ODORS FROM ANAEROBIC LAGOONS TREATING FOOD PROCESSING WASTEWATERS

    EPA Science Inventory

    Anaerobic lagoons are used for the treatment of meat packing wastes in most areas of the country. They are a relatively low cost means of achieving BOD reduction. Although lagoon effluent is not suitable for stream discharge, it is amenable to further treatment or to land applica...

  13. Optimizing anaerobic soil disinfestation for soilborne disease control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soilborne disease management without chemical fumigants is a major challenge for strawberry production in California. Current re-registrations and regulations are likely to intensify this obstacle by severely limiting availability of fumigants on a large percentage of strawberry acreage. Anaerobic s...

  14. The Impact of Temperature on Anaerobic Biological Perchlorate Treatment

    EPA Science Inventory

    A 20-month pilot-scale study was conducted to examine the impact of temperature on the performance of an anaerobic biological contactor used to treat perchlorate-contaminated water. The contactor was successfully acclimated with indigenous micro-organisms. Influent temperatures...

  15. Evaluating C-sources for anaerobic soil disinfestation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic soil disinfestation (ASD) has been shown to be effective in the control of a wide range of soil-borne plant pathogens. Efficacy of ASD was previously shown to be influenced by carbon input utilized when applied to apple orchard systems. In strawberry, ASD provided comparable yield as that...

  16. Phosphorus update by potato from fertilizers recovered from anaerobic digestion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field experiments were conducted in the Columbia Basin of South Central Washington to assess the yield of potato (Solanum tuberosum) in response to application of phosphorus enriched materials recovered from anaerobic digestion of manure. The treatments were comprised of four rates (0, 56, 112 and ...

  17. Allometric Scaling of Wingate Anaerobic Power Test Scores in Women

    ERIC Educational Resources Information Center

    Hetzler, Ronald K.; Stickley, Christopher D.; Kimura, Iris F.

    2011-01-01

    In this study, we developed allometric exponents for scaling Wingate anaerobic test (WAnT) power data that are reflective in controlling for body mass (BM) and lean body mass (LBM) and established a normative WAnT data set for college-age women. One hundred women completed a standard WAnT. Allometric exponents and percentile ranks for peak (PP)…

  18. Relating methanogen community structure and anaerobic digester function.

    PubMed

    Bocher, B T W; Cherukuri, K; Maki, J S; Johnson, M; Zitomer, D H

    2015-03-01

    Much remains unknown about the relationships between microbial community structure and anaerobic digester function. However, knowledge of links between community structure and function, such as specific methanogenic activity (SMA) and COD removal rate, are valuable to improve anaerobic bioprocesses. In this work, quantitative structure-activity relationships (QSARs) were developed using multiple linear regression (MLR) to predict SMA using methanogen community structure descriptors for 49 cultures. Community descriptors were DGGE demeaned standardized band intensities for amplicons of a methanogen functional gene (mcrA). First, predictive accuracy of MLR QSARs was assessed using cross validation with training (n = 30) and test sets (n = 19) for glucose and propionate SMA data. MLR equations correlating band intensities and SMA demonstrated good predictability for glucose (q(2) = 0.54) and propionate (q(2) = 0.53). Subsequently, data from all 49 cultures were used to develop QSARs to predict SMA values. Higher intensities of two bands were correlated with higher SMA values; high abundance of methanogens associated with these two bands should be encouraged to attain high SMA values. QSARs are helpful tools to identify key microorganisms or to study and improve many bioprocesses. Development of new, more robust QSARs is encouraged for anaerobic digestion or other bioprocesses, including nitrification, nitritation, denitrification, anaerobic ammonium oxidation, and enhanced biological phosphorus removal. PMID:25562581

  19. ANAEROBIC SUBSTRATE TOLERANCE IN'SPOROBOLUS VIRGINICUS' (L.) KUNTH

    EPA Science Inventory

    The purpose of this study was to determine if and how the two genetically distinct forms, marsh and dune, of Sporobolus virginicus, tolerate anaerobic substrates. The treatments in the hydroponic study, conducted in the greenhouse for approximately 6 months, involved growing the ...

  20. Improving products of anaerobic sludge digestion by microaeration.

    PubMed

    Jenicek, P; Celis, C A; Krayzelova, L; Anferova, N; Pokorna, D

    2014-01-01

    Biogas, digested sludge and sludge liquor are the main products of anaerobic sludge digestion. Each of the products is influenced significantly by specific conditions of the digestion process. Therefore, any upgrade of the digestion technology must be considered with regard to quality changes in all products. Microaeration is one of the methods used for the improvement of biogas quality. Recently, microaeration has been proved to be a relatively simple and highly efficient biological method of sulfide removal in the anaerobic digestion of biosolids, but little attention has been paid to comparing the quality of digested sludge and sludge liquor in the anaerobic and microaerobic digestion and that is why this paper primarily deals with this area of research. The results of the long-term monitoring of digested sludge quality and sludge liquor quality in the anaerobic and microaerobic digesters suggest that products of both technologies are comparable. However, there are several parameters in which the 'microaerobic' products have a significantly better quality such as: sulfide (68% lower) and soluble chemical oxygen demand (COD) (33% lower) concentrations in the sludge liquor and the lower foaming potential of the digested sludge. PMID:24569280

  1. Anaerobic fermentation of beef cattle manure. Final report

    SciTech Connect

    Hashimoto, A.G.; Chen, Y.R.; Varel, V.H.

    1981-01-01

    The research to convert livestock manure and crop residues into methane and a high protein feed ingredient by thermophilic anaerobic fermentation are summarized. The major biological and operational factors involved in methanogenesis were discussed, and a kinetic model that describes the fermentation process was presented. Substrate biodegradability, fermentation temperature, and influent substrate concentration were shown to have significant effects on CH/sub 4/ production rate. The kinetic model predicted methane production rates of existing pilot and full-scale fermentation systems to within 15%. The highest methane production rate achieved by the fermenter was 4.7 L CH/sub 4//L fermenter day. This is the highest rate reported in the literature and about 4 times higher than other pilot or full-scale systems fermenting livestock manures. Assessment of the energy requirements for anaerobic fermentation systems showed that the major energy requirement for a thermophilic system was for maintaining the fermenter temperature. The next major energy consumption was due to the mixing of the influent slurry and fermenter liquor. An approach to optimizing anaerobic fermenter designs by selecting design criteria that maximize the net energy production per unit cost was presented. Based on the results, we believe that the economics of anaerobic fermentation is sufficiently favorable for farm-scale demonstration of this technology.

  2. COMMERCIAL-SCALE AEROBIC-ANAEROBIC BIOREACTOR LANDFILL OPERATIONS

    EPA Science Inventory

    A sequential aerobic-anaerobic treatment system has been applied at a commercial scale (3,000 ton per day) municipal solid waste landfill in Kentucky, USA since 2001. In this system, the uppermost layer of landfilled waste is aerated and liquid waste including leachate, surface w...

  3. Susceptibility of Anaerobic Bacteria to 23 Antimicrobial Agents

    PubMed Central

    Sutter, Vera L.; Finegold, Sydney M.

    1976-01-01

    The antimicrobial susceptibility of 492 anaerobic bacteria, the majority of which were recent clinical isolates, was determined by the agar dilution technique. Penicillin G was active against most of the strains tested at 32 U or less/ml, but only 72% of Bacteroides fragilis strains were susceptible at this level and 9% required 256 U or more/ml. Ampicillin was effective against most of the strains except B. fragilis at 16 μg or less/ml. Amoxicillin was active against only 31% of B. fragilis, 76% of other Bacteroides species, and 67% of Fusobacterium species at 8 μg/ml. Two new penicillins, mezlocillin and azlocillin, were similar to ampicillin in their activity. Carbenicillin and ticarcillin inhibited all but a few strains at 128 μg or less/ml. BLP 1654 was somewhat more active than penicillin G against B. fragilis but had similar activity against other anaerobes. Cephalothin was inactive against B. fragilis, and only 65% of other Bacteroides species were inhibited by 32 μg or less/ml. It was effective against all other anaerobes at that level. Cefamandole showed somewhat greater activity than cephalothin against B. fragilis but generally less activity against gram-positive organisms. Cefazaflur (SKF 59962) was comparable to cephalothin against B. fragilis. Cefoxitin was distinctly more active than cephalothin against B. fragilis. These latter two agents were less active than cephalothin against the gram-positive anaerobes. Chloramphenicol remains active against anaerobic bacteria at 16 μg or less/ml, with rare exceptions. Thiamphenicol was similar to chloramphenicol in its activity. Clindamycin was very active against most of the anaerobes at 8 μg or less/ml. Erythromycin and josamycin were also tested, with josamycin showing greater activity against B. fragilis than either erythromycin or clindamycin. A new oligosaccharide, everninomicin B, was less active than clindamycin against B. fragilis but more active against clostridia and some of the other strains

  4. Animal and industrial waste anaerobic digestion: USA status report

    SciTech Connect

    Lusk, P.D.

    1996-01-01

    Pollutants from unmanaged animal and bio-based industrial wastes can degrade the environment, and methane emitted from decomposing wastes may contribute to global climate change. One waste management system prevents pollution and converts a disposal problem into a new profit center. Case studies of operating systems indicate that the anaerobic digestion of animal and industrial wastes is a commercially available bioconversion technology with considerable potential for providing profitable coproducts, including a cost-effective renewable fuel. Growth and concentration of the livestock industry create opportunities to properly dispose of the large quantities of manures generated at dairy, swine, and poultry farms. Beyond the farm, extension of the anaerobic digestion process to recover methane has considerable potential for certain classified industries - with a waste stream characterization similar to livestock manures. More than 35 example industries have been identified, and include processors of chemicals, fiber, food, meat, milk, and pharmaceuticals. Some of these industries already recover methane for energy. This status report examines some current opportunities for recovering methane from the anaerobic digestion of animal and industrial wastes in the US. Case studies of operating digesters, including project and maintenance histories, and the operator`s {open_quotes}lessons learned,{close_quotes} are included as a reality check. Factors necessary for successful projects, as well as a list of reasons explaining why some anaerobic digestion projects fail, are provided. The role of management is key; not only must digesters be well engineered and built with high-quality components, they must also be sited at facilities willing to incorporate the uncertainties of a new technology. Anaerobic digestion can provide monetary benefits and mitigate possible pollution problems, thereby sustaining development while maintaining environmental quality.

  5. [Anaerobic bacteria 150 years after their discovery by Pasteur].

    PubMed

    García-Sánchez, José Elías; García-Sánchez, Enrique; Martín-Del-Rey, Ángel; García-Merino, Enrique

    2015-02-01

    In 2011 we celebrated the 150th anniversary of the discovery of anaerobic bacteria by Louis Pasteur. The interest of the biomedical community on such bacteria is still maintained, and is particularly focused on Clostridium difficile. In the past few years important advances in taxonomy have been made due to the genetic, technological and computing developments. Thus, a significant number of new species related to human infections have been characterised, and some already known have been reclassified. At pathogenic level some specimens of anaerobic microflora, that had not been isolated from human infections, have been now isolated in some clinical conditions. There was emergence (or re-emergence) of some species and clinical conditions. Certain anaerobic bacteria have been associated with established infectious syndromes. The virulence of certain strains has increased, and some hypotheses on their participation in certain diseases have been given. In terms of diagnosis, the routine use of MALDI-TOF has led to a shortening of time and a cost reduction in the identification, with an improvement directly related to the improvement of data bases. The application of real-time PCR has been another major progress, and the sequencing of 16srRNA gene and others is currently a reality for several laboratories. Anaerobes have increased their resistance to antimicrobial agents, and the emergence of resistance to carbapenems and metronidazole, and multi-resistance is a current reality. In this situation, linezolid could be an effective alternative for Bacteroides. Fidaxomicin is the only anti-anaerobic agent introduced in the recent years, specifically for the diarrhoea caused by C.difficile. Moreover, some mathematical models have also been proposed in relation with this species. PMID:23648369

  6. Kinetics of thermophilic anaerobes in fixed-bed reactors.

    PubMed

    Perez, M; Romero, L I; Sales, D

    2001-08-01

    The main objective of this study is to estimate growth kinetic constants and the concentration of "active" attached biomass in two anaerobic thermophilic reactors which contain different initial sizes of immobilized anaerobic mixed cultures and decompose distillery wastewater. This paper studies the substrate decomposition in two lab-scale fixed-bed reactors operating at batch conditions with corrugated tubes as support media. It can be demonstrated that high micro-organisms-substrate ratios favor the degradation activity of the different anaerobic cultures, allowing the stable operation without lag-phases and giving better quality in effluent. The kinetic parameters obtained--maximum specific growth rates (mu(max)), non-biodegradable substrate (S(NB)) and "active or viable biomass" concentrations (X(V0))--were obtained by applying the Romero kinetic model [L.I. Romero, 1991. Desarrollo de un modelo matemático general para los procesos fermentativos, Cinética de la degradación anaerobia, Ph.D. Thesis, University of Cádiz (Spain), Serv. Pub. Univ. Cádiz], with COD as substrate and methane (CH4) as the main product of the anaerobic process. This method is suitable to calculate and to differentiate the main kinetic parameters of both the total anaerobic mixed culture and the methanogenic population. Comparison of experimental measured concentration of volatile attached solids (VS(att)) in both reactors with the estimated "active" biomass concentrations obtained by applying Romero kinetic model [L.I. Romero, 1991. Desarrollo de un modelo matemático general para los procesos fermentativos, Cinética de la degradación anaerobia, Ph.D. Thesis, University of Cádiz (Spain), Serv. Pub. Univ. Cádiz] shows that a large amount of inert matter is present in the fixed-bed reactor. PMID:11513409

  7. Identification of a conserved protein involved in anaerobic unsaturated fatty acid synthesis in Neiserria gonorrhoeae: implications for facultative and obligate anaerobes that lack FabA.

    PubMed

    Isabella, Vincent M; Clark, Virginia L

    2011-10-01

    Transcriptome analysis of the facultative anaerobe, Neisseria gonorrhoeae, revealed that many genes of unknown function were induced under anaerobic conditions. Mutation of one such gene, NGO1024, encoding a protein belonging to the 2-nitropropane dioxygenase-like superfamily of proteins, was found to result in an inability of gonococci to grow anaerobically. Anaerobic growth of an NG1024 mutant was restored upon supplementation with unsaturated fatty acids (UFA), but not with the saturated fatty acid palmitate. Gonococcal fatty acid profiles confirmed that NGO1024 was involved in UFA synthesis anaerobically, but not aerobically, demonstrating that gonococci contain two distinct pathways for the production of UFAs, with a yet unidentified aerobic mechanism, and an anaerobic mechanism involving NGO1024. Expression of genes involved in classical anaerobic UFA synthesis, fabA, fabM and fabB, was toxic in gonococci and unable to complement a NGO1024 mutation, suggesting that the chemistry involved in gonococcal anaerobic UFA synthesis is distinct from that of the classical pathway. NGO1024 homologues, which we suggest naming UfaA, form a distinct lineage within the 2-nitropropane dioxygenase-like superfamily, and are found in many facultative and obligate anaerobes that produce UFAs but lack fabA, suggesting that UfaA is part of a widespread pathway involved in UFA synthesis. PMID:21895795

  8. Improve bio-activity of anaerobic sludge by low energy ultrasound.

    PubMed

    Zhu, Yichun; Li, Xin; Du, Maoan; Liu, Zuwen; Luo, Hui; Zhang, Tao

    2015-01-01

    This research focused on ultrasound-enhanced bio-activity of anaerobic sludge. Low energy ultrasound irradiation can increase the bio-activity of anaerobic sludge. Ultrasonic parameter, characteristics of anaerobic sludge and experimental conditions are important parameters which affect the enhancement effect on anaerobic sludge. In order to assess the effects of characteristics of anaerobic sludge and experimental conditions on ultrasonic irradiation of anaerobic sludge, experiments with different characteristics of anaerobic sludge were carried out and analyzed with the content of coenzyme F420 and dehydrogenase activity (DHA). The results showed that anaerobic sludge bio-activity was impacted by the initial temperature, initial chemical oxygen demand (COD), sludge concentration, and stirring during the ultrasonic process. Optimal performance was achieved when sound frequency, power density, and ultrasonic irradiation period was 20 kHz, 0.1 W/mL, and 10 min, respectively, under which the wastewater COD removal efficiency was increased by 12.9 percentage points. The results indicated that low temperature could affect the anaerobic sludge irradiation effect, while intermittent stirring could enhance the bio-activity of anaerobic sludge irradiation effect and low substrate concentration improved anaerobic sludge activity by ultrasound. PMID:26676010

  9. Modelling of two-stage anaerobic digestion using the IWA Anaerobic Digestion Model No. 1 (ADM1).

    PubMed

    Blumensaat, F; Keller, J

    2005-01-01

    The aim of the study presented was to implement a process model to simulate the dynamic behaviour of a pilot-scale process for anaerobic two-stage digestion of sewage sludge. The model implemented was initiated to support experimental investigations of the anaerobic two-stage digestion process. The model concept implemented in the simulation software package MATLAB/Simulink is a derivative of the IWA Anaerobic Digestion Model No.1 (ADM1) that has been developed by the IWA task group for mathematical modelling of anaerobic processes. In the present study the original model concept has been adapted and applied to replicate a two-stage digestion process. Testing procedures, including balance checks and 'benchmarking' tests were carried out to verify the accuracy of the implementation. These combined measures ensured a faultless model implementation without numerical inconsistencies. Parameters for both, the thermophilic and the mesophilic process stage, have been estimated successfully using data from lab-scale experiments described in literature. Due to the high number of parameters in the structured model, it was necessary to develop a customised procedure that limited the range of parameters to be estimated. The accuracy of the optimised parameter sets has been assessed against experimental data from pilot-scale experiments. Under these conditions, the model predicted reasonably well the dynamic behaviour of a two-stage digestion process in pilot scale. PMID:15607176

  10. Navigating wastewater energy recovery strategies: a life cycle comparison of anaerobic membrane bioreactor and conventional treatment systems with anaerobic digestion.

    PubMed

    Smith, Adam L; Stadler, Lauren B; Cao, Ling; Love, Nancy G; Raskin, Lutgarde; Skerlos, Steven J

    2014-05-20

    The objective of this study was to evaluate emerging anaerobic membrane bioreactor (AnMBR) technology in comparison with conventional wastewater energy recovery technologies. Wastewater treatment process modeling and systems analyses were combined to evaluate the conditions under which AnMBR may produce more net energy and have lower life cycle environmental emissions than high rate activated sludge with anaerobic digestion (HRAS+AD), conventional activated sludge with anaerobic digestion (CAS+AD), and an aerobic membrane bioreactor with anaerobic digestion (AeMBR+AD). For medium strength domestic wastewater treatment under baseline assumptions at 15 °C, AnMBR recovered 49% more energy as biogas than HRAS+AD, the most energy positive conventional technology considered, but had significantly higher energy demands and environmental emissions. Global warming impacts associated with AnMBR were largely due to emissions of effluent dissolved methane. For high strength domestic wastewater treatment, AnMBR recovered 15% more net energy than HRAS+AD, and the environmental emissions gap between the two systems was reduced. Future developments of AnMBR technology in low energy fouling control, increased flux, and management of effluent methane emissions would make AnMBR competitive with HRAS+AD. Rapid advancements in AnMBR technology must continue to achieve its full economic and environmental potential as an energy recovery strategy for domestic wastewater. PMID:24742289

  11. Anaerobic treatment of municipal wastewater with a staged anaerobic fluidized membrane bioreactor (SAF-MBR) system.

    PubMed

    Yoo, Rihye; Kim, Jeonghwan; McCarty, Perry L; Bae, Jaeho

    2012-09-01

    A laboratory-scale staged anaerobic fluidized membrane bioreactor (SAF-MBR) system was used to treat a municipal wastewater primary-clarifier effluent. It was operated continuously for 192 days at 6-11 L/m(2)/h flux and trans-membrane pressure generally of 0.1 bar or less with no fouling control except the scouring effect of the fluidized granular activated carbon on membrane surfaces. With a total hydraulic retention time of 2.3h at 25°C, the average effluent chemical oxygen demand and biochemical oxygen demand concentrations of 25 and 7 mg/L yielded corresponding removals of 84% and 92%, respectively. Also, near complete removal of suspended solids was obtained. Biosolids production, representing 5% of the COD removed, equaled 0.049 g VSS/g BOD(5) removed, far less than the case with comparable aerobic processes. The electrical energy required for the operation of the SAF-MBR system, 0.047 kW h/m(3), could be more than satisfied by using the methane produced. PMID:22784964

  12. Upflow anaerobic sludge blanket reactor--a review.

    PubMed

    Bal, A S; Dhagat, N N

    2001-04-01

    Biological treatment of wastewater basically reduces the pollutant concentration through microbial coagulation and removal of non-settleable organic colloidal solids. Organic matter is biologically stabilized so that no further oxygen demand is exerted by it. The biological treatment requires contact of the biomass with the substrate. Various advances and improvements in anaerobic reactors to achieve variations in contact time and method of contact have resulted in development of in suspended growth systems, attached growth or fixed film systems or combinations thereof. Although anaerobic systems for waste treatment have been used since late 19th century, they were considered to have limited treatment efficiencies and were too slow to serve the needs of a quickly expanding wastewater volume, especially in industrialized and densely populated areas. At present aerobic treatment is the most commonly used process to reduce the organic pollution level of both domestic and industrial wastewaters. Aerobic techniques, such as activated sludge process, trickling filters, oxidation ponds and aerated lagoons, with more or less intense mixing devices, have been successfully installed for domestic wastewater as well as industrial wastewater treatment. Anaerobic digestion systems have undergone modifications in the last two decades, mainly as a result of the energy crisis. Major developments have been made with regard to anaerobic metabolism, physiological interactions among different microbial species, effects of toxic compounds and biomass accumulation. Recent developments however, have demonstrated that anaerobic processes might be an economically attractive alternative for the treatment of different types of industrial wastewaters and in (semi-) tropical areas also for domestic wastewaters. The anaerobic degradation of complex, particulate organic matter has been described as a multistep process of series and parallel reactions. It involves the decomposition of organic and

  13. Anaerobic Biotransformation and Mobility of Pu and Pu-EDTA

    SciTech Connect

    Bolton, H., Jr.; Rai, D.; Xun, L.

    2005-04-18

    The complexation of radionuclides (e.g., plutonium (Pu) and {sup 60}Co) by codisposed ethylenediaminetetraacetate (EDTA) has enhanced their transport in sediments at DOE sites. Our previous NABIR research investigated the aerobic biodegradation and biogeochemistry of Pu(IV)-EDTA. Plutonium(IV) forms stable complexes with EDTA under aerobic conditions and an aerobic EDTA degrading bacterium can degrade EDTA in the presence of Pu and decrease Pu mobility. However, our recent studies indicate that while Pu(IV)-EDTA is stable in simple aqueous systems, it is not stable in the presence of relatively soluble Fe(III) compounds (i.e., Fe(OH){sub 3}(s)--2-line ferrihydrite). Since most DOE sites have Fe(III) containing sediments, Pu(IV) in likely not the mobile form of Pu-EDTA in groundwater. The only other Pu-EDTA complex stable in groundwater relevant to DOE sites would be Pu(III)-EDTA, which only forms under anaerobic conditions. Research is therefore needed in this brand new project to investigate the biotransformation of Pu and Pu-EDTA under anaerobic conditions. The biotransformation of Pu and Pu-EDTA under various anaerobic regimes is poorly understood including the reduction kinetics of Pu(IV) to Pu(III) from soluble (Pu(IV)-EDTA) and insoluble Pu(IV) as PuO2(am) by metal reducing bacteria, the redox conditions required for this reduction, the strength of the Pu(III)-EDTA complex, how the Pu(III)-EDTA complex competes with other dominant anoxic soluble metals (e.g., Fe(II)), and the oxidation kinetics of Pu(III)-EDTA. Finally, the formation of a stable soluble Pu(III)-EDTA complex under anaerobic conditions would require degradation of the EDTA complex to limit Pu(III) transport in geologic environments. Anaerobic EDTA degrading microorganisms have not been isolated. These knowledge gaps preclude the development of a mechanistic understanding of how anaerobic conditions will influence Pu and Pu-EDTA fate and transport to assess, model, and design approaches to stop

  14. Anaerobic Biodegradation of Raw and Pre-treated Brewery Spent Grain Utilizing Solid State Anaerobic Digestion.

    PubMed

    Panjičko, Mario; Zupančič, Gregor Drago; Zelić, Bruno

    2015-01-01

    The brewery spent grain (BSG) represents approximately 85% of the total quantity of by-products from the brewing industry. The biogas production from the BSG has been the subject of several studies in recent years, due to relatively high energy consumption in the brewing process and due to the increasing energy costs. The biodegradability of raw and pre-treated BSG in a single-stage and two-stage solid-state anaerobic digestion (SS-AD) system was determined in this study. The results show that the BSG have a biogas potential of 120 L/kg(-1). In the single-stage system, the biogas yield obtained from raw BSG (87.4 L/kg(-1)) was almost equal to the yield obtained from the pre-treated BSG (89.1 L/kg(-1)), while the methane yield was 51.9 and 55.3 L/kg(-1) and the biodegradation was 62.0% and 62.2% for raw and pre-treated BSG, respectively. In two-stage SS-AD the pre-treated BSG showed better results, with the biogas yield of 103.2 L/kg(-1) and the biodegradation of 73.6%, while the biogas yield obtained from raw BSG was 89.1 L/kg(-1), with the biodegradation of 63.5%. In two-stage process the obtained methane yields from raw and pre-treated BSG were identical (58.7 L/kg(-1)). PMID:26680709

  15. Anaerobic digestibility of marine microalgae Phaeodactylum tricornutum in a lab-scale anaerobic membrane bioreactor.

    PubMed

    Zamalloa, Carlos; De Vrieze, Jo; Boon, Nico; Verstraete, Willy

    2012-01-01

    The biomass of industrially grown Phaeodactylum tricornutum was subjected in a novel way to bio-methanation at 33°C, i.e., in an anaerobic membrane bioreactor (AnMBR) at a hydraulic retention time of 2.5 days, at solid retention times of 20 to 10 days and at loading rates in the range of 2.6-5.9 g biomass-COD L(-1) day(-1) with membrane fluxes ranging from 1 to 0.8 L m(-2) h(-1). The total COD recovered as biogas was in the order of 52%. The input suspension was converted to a clear effluent rich in total ammonium nitrogen (546 mg TAN L(-1)) and phosphate (141 mg PO(4)-P L(-1)) usable as liquid fertilizer. The microbial community richness, dynamics, and organization in the reactor were interpreted using the microbial resource management approach. The AnMBR communities were found to be moderate in species richness and low in dynamics and community organization relative to UASB and conventional CSTR sludges. Quantitative polymerase chain reaction analysis revealed that Methanosaeta sp. was the dominant acetoclastic methanogen species followed by Methanosarcina sp. This work demonstrated that the use of AnMBR for the digestion of algal biomass is possible. The fact that some 50% of the organic matter is not liquefied means that the algal particulates in the digestate constitute a considerable fraction which should be valorized properly, for instance as slow release organic fertilizer. Overall, 1 kg of algae dry matter (DM) could be valorized in the form of biogas ( euro 2.07), N and P in the effluent (euro 0.02) and N and P in the digestate (euro 0.04), thus totaling about euro 2.13 per kilogram algae DM. PMID:22005739

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

    PubMed

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

    2016-09-01

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

  17. A model for anaerobic ponds combining settling and biological processes.

    PubMed

    Effebi, K R; Jupsin, H; Keffala, C; Vasel, J L

    2013-01-01

    This work presents an approach to an anaerobic pond model by combining the stoichiometry of the hydrolysis and acidogenic processes of the main constituents of wastewater, i.e. carbohydrates, proteins, and lipids, grouped as a 'combined substrate' with a previously published settling model (see 'Suspended solids settling and half removal time in stabilization ponds (Tunisia)' by Effebi et al. (2011)). This approach includes biomass production. Coupling the kinetics and stoichiometry of the previous processes with the usual methanogenic model, we developed an anaerobic pond model. This paper gives the stoichiometry of the different chemical reactions that occur during the degradation of a conventional influent (corresponding to what we define as a 'combined substrate') of domestic wastewater and the model's first results. PMID:23787301

  18. Mechanism of anaerobic degradation of triethanolamine by a homoacetogenic bacterium

    SciTech Connect

    Speranza, Giovanna . E-mail: giovanna.speranza@unimi.it; Morelli, Carlo F.; Cairoli, Paola; Mueller, Britta; Schink, Bernhard

    2006-10-20

    Triethanolamine (TEA) is converted into acetate and ammonia by a strictly anaerobic, gram-positive Acetobacterium strain LuTria3. Fermentation experiments with resting cell suspensions and specifically deuterated substrates indicate that in the acetate molecule the carboxylate and the methyl groups correspond to the alcoholic function and to its adjacent methylene group, respectively, of the 2-hydroxyethyl unit of TEA. A 1,2 shift of a hydrogen (deuterium) atom from -CH{sub 2} -O- to =N-CH{sub 2} - without exchange with the medium was observed. This fact gives evidence that a radical mechanism occurs involving the enzyme and/or coenzyme molecule as a hydrogen carrier. Such a biodegradation appears analogous to the conversion of 2-phenoxyethanol into acetate mediated by another strain of the anaerobic homoacetogenic bacterium Acetobacterium.

  19. Anaerobic bacteria from the large intestine of mice.

    PubMed Central

    Harris, M A; Reddy, C A; Carter, G R

    1976-01-01

    Anaerobic bacteria from the colon of laboratory mice were enumerated and isolated using strict anaerobic techniques. Direct microscopic counts revealed 4.4 X 10(10) organisms in each gram (wet weight) of colon contents. Actual cultural counts averaged 3.2 X 10(10) organisms, which was 73% of the direct microscopic count. The tentatively identified genera were Bacteroides, Eubacterium, Fusobacterium, Lactobacillus, Peptostreptococcus, and Propionibacterium. Strains of Fusobacterium, Lactobacillus, Peptostreptococcus, and Propionibacterium were biochemically homogeneous. Strains of Bacteroides and Eubacterium, on the other hand, were biochemically heterogeneous and were subdivided into several distinct groups. The data indicate that many of the isolates are different from previously described species of the respective genera and may belong to new species. PMID:938042

  20. Pollution and energy management through the anaerobic approach

    SciTech Connect

    Szendrey, L.M.; Dorion, G.H.; Schafer, P.E.

    1982-09-01

    Describes how a rum producer on Puerto Rico is using an anaerobic reactor to convert distillery wastes to methane gas. Reports that the reactor generates enough methane to replace 75 barrels of fuel oil per day while reducing the biochemical oxygen demand (BOD) load. Explains that the reactor is loaded with microbial seed, water and mosto at a rate of 50,000 gpd. Plant operations, requiring minimal personnel, involve maintenance of correct environment for anaerobic microorganisms through periodic adjustment of pH and temperature. Points out that many modifications are possible, and thus the Bacardi process is applicable to still-bottom wastes, spent grain liquors, centrates, pulp and paper wastes, sweet or acid cheese whey, food packing and meat packing wastes, liquid extraction raffinates, sludge heat treatment sidestreams, corn products wastes, protein extraction wastes, and winery wastes.

  1. Facultative to strict anaerobes ratio in the preterm infant microbiota

    PubMed Central

    Arboleya, Silvia; Solís, Gonzalo; Fernández, Nuria; de los Reyes-Gavilán, Clara G.; Gueimonde, Miguel

    2012-01-01

    During recent years there has been an increasing interest on the development of strategies for modulating the process of microbiota establishment in preterm infants. For successfully developing of such strategies, a detailed knowledge of the microbiota establishment process in these infants is needed. In a previous study we evidenced clear alterations in the process of microbiota establishment in preterm newborns when compared with a control group of full-term breast-fed infants. Here we have analyzed these data more in depth, corroborating a reduced proportion of strict anaerobes with respect to facultatives in the fecal microbiota of preterm infants. The potential benefits, as well as the side effects, of strategies aimed at counterbalancing this alteration in the facultative to strict anaerobes ratio are discussed in this addendum. PMID:22922559

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

    PubMed

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

    2015-10-01

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

  3. Sediment bacterial communities associated with anaerobic biodegradation of bisphenol A.

    PubMed

    Yang, Yuyin; Wang, Zhao; He, Tao; Dai, Yu; Xie, Shuguang

    2015-07-01

    Bisphenol A (BPA) is one of the endocrine-disrupting chemicals that are ubiquitous in aquatic environments. Biodegradation is a major way to clean up the BPA pollution in sediments. However, information on the effective BPA biodegradation in anaerobic sediments is still lacking. The present study investigated the biodegradation potential of BPA in river sediment under nitrate- or sulfate-reducing conditions. After 120-day incubation, a high removal of BPA (93 or 89%) was found in sediment microcosms (amended with 50 mg kg(-1) BPA) under these two anaerobic conditions. Illumina MiSeq sequencing analysis indicated that Proteobacteria, Bacteroidetes, Chloroflexi, Firmicutes, Gemmatimonadetes, and Actinobacteria were the major bacterial groups in BPA-degrading sediments. The shift in bacterial community structure could occur with BPA biodegradation. PMID:25501890

  4. Anaerobic cultures from preserved tissues of baby mammoth

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

  5. Anaerobic treatment of a furfural-production wastewater

    SciTech Connect

    Wirtz, R.A.; Dague, R.R. . Dept. of Civil and Construction Engineering)

    1993-01-01

    The laboratory-scale treatment of a furfural-byproduct wastewater containing approximately 1.2% acetic acid was investigated using one fully-packed anaerobic filter and one partially-packed anaerobic upflow blanket filter operated at 35 C. Hydraulic retention times of 24 and 12 h were investigated, with organic loading rates ranging from 3 to 26 g COD/L/day. COD removal efficiencies in excess of 90% were observed for both reactors at organic loading up to 23 g/L/day. Experiments at both HRTs were conducted to determine the effect on performance of a two-week shut-down of the reactors. Results from the shut-down studies indicated that the fully-packed filter handled the shut-down periods more efficiently than did the blanket filter.

  6. Manganese inhibition of microbial iron reduction in anaerobic sediments

    USGS Publications Warehouse

    Lovley, D.R.; Phillips, E.J.P.

    1988-01-01

    Potential mechanisms for the lack of Fe(II) accumulation in Mn(IV)-containing anaerobic sediments were investigated. The addition of Mn(IV) to sediments in which Fe(II) reduction was the terminal electron-accepting process removed all the pore-water Fe(II), completely inhibited net Fe(III) reduction, and stimulated Mn(IV) reduction. Results demonstrate that preferential reduction of Mn(IV) by FE(III)-reducing bacteria cannot completely explain the lack of Fe(II) accumulation in anaerobic, Mn(IV)-containing sediments, and indicate that Mn(IV) oxidation of Fe(II) is the mechanism that ultimately prevents Fe(II) accumulation. -Authors

  7. Anaerobic treatment of municipal wastewater using the UASB-technology.

    PubMed

    Urban, I; Weichgrebe, D; Rosenwinkel, K-H

    2007-01-01

    The anaerobic treatment of municipal wastewater enables new applications for the reuse of wastewater. The effluent could be used for irrigation as the included nutrients are not affected by the treatment. Much more interesting now are renewable energies and the retrenchment of CO(2) emission. With the anaerobic treatment of municipal wastewater, not only can the CO(2) emission be reduced but "clean" energy supply can be gained by biogas. Most important for the sustainability of this process is the gathering of methane from the liquid effluent of the reactor, because the negative climate-relevant effect from the degassing methane is much higher than the positive effect from saving CO(2) emission. In this study, UASB reactors were used with a flocculent sludge blanket for the biodegradation of the carbon fraction in the wastewater with different temperatures and concentrations. It could be shown that the positive effect is much higher for municipal wastewater with high concentrations in hot climates. PMID:18048975

  8. Anaerobic conditions improve germination of a gibberellic acid deficient rice

    NASA Technical Reports Server (NTRS)

    Frantz, Jonathan M.; Bugbee, Bruce

    2002-01-01

    Dwarf plants are useful in research because multiple plants can be grown in a small area. Rice (Oryza sativa L.) is especially important since its relatively simple genome has recently been sequenced. We are characterizing a gibberellic acid (GA) mutant of rice (japonica cv 'Shiokari,' line N-71) that is extremely dwarf (20 cm tall). Unfortunately, this GA mutation is associated with poor germination (70%) under aerobic conditions. Neither exogenous GA nor a dormancy-breaking heat treatment improved germination. However, 95% germination was achieved by germinating the seeds anaerobically, either in a pure N2 environment or submerged in unstirred tap water. The anaerobic conditions appear to break a mild post-harvest dormancy in this rice cultivar. Copyright 2002 Crop Science Society of America.

  9. Evaluating anaerobic digestion for reduction of organic wastes

    SciTech Connect

    Hartung, H.A.

    1994-12-31

    A small-scale anaerobic digestion test has been developed for monitoring start-up work with inoperative digesters. The test is described and variables critical to its consistent operation are detailed. The method has been used in many anaerobic digestion studies, including evaluation of the digestibility of various municipal solid wastes like grass and hedge clippings, garbage and newspapers. Digestion rates are expressed in terms of the rate of production of combustible gas and the retention time needed for a fixed degree of volatile solids destruction. An example shows the advantage of digesting selected combined charges, and it is suggested that this approach might be fruitful with many toxic organic materials. Application of this test to find the digestion rates of some high-yield biomass crops is also described.

  10. Waste heat utilization in an anaerobic digestion system

    NASA Astrophysics Data System (ADS)

    Boissevain, Brett

    Anaerobic digestion has great potential as an energy source. Not only does it provide an effective method for waste mitigation, but it has the potential to generate significant quantities of fuel and electricity. In order to ensure efficient digestion and biomass utilization, however, the system must be continuously maintained at elevated temperatures. It is technically feasible to supplement such a system with outside energy, but it is more cost effective to heat the system using only the produced biogas. While there is considerable literature covering the theory of anaerobic digestion, there are very few practical studies to show how heat utilization affects system operation. This study considers the effect of major design variables (i.e. heat exchanger efficiencies and biogas conditioning) on promoting a completely self-sustaining digestion system. The thesis considers a real world system and analyzes how it can be improved to avoid the need of an external energy source.

  11. A novel technique for evaluating foam dynamics in anaerobic digesters.

    PubMed

    Park, C; Hermanowicz, S W; Jolis, D

    2013-01-01

    Foaming in anaerobic digesters has severe impacts on process efficiency and operational costs. In this study, we present an experimental method to determine foam behaviour and stability for various foaming solutions. This novel technique measured foam conductivity at different heights along a foam column allowing changes in foam composition to be monitored in time. We analysed foam stability which is primarily dependent on the foam drainage velocity, a quantity that can be determined from forced drainage experiments. The drainage velocity increased in the presence of anaerobic digester sludge, compared to simple surfactant foam. We proposed a new understanding of the effect of sludge particles on the foam stability. Both physical properties (foam physical constant, β) of foam and bubble surface interactions by applying stable and unstable foam in addition of surfactants are also evaluated and discussed. PMID:23752394

  12. Anaerobic Cultures from Preserved Tissues of Baby Mammoth

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  13. Acclimation strategy to increase phenol tolerance of an anaerobic microbiota.

    PubMed

    Madigou, Céline; Poirier, Simon; Bureau, Chrystelle; Chapleur, Olivier

    2016-09-01

    A wide variety of inhibitory substances can induce anaerobic digester upset or failure. In this work the possibility to improve the resistance of an anaerobic microbiota to a common pollutant, the phenol, was evaluated in a lab-scale semi-continuous bioreactor. An acclimation strategy, consisting in a regular step-wise adaptation of the microbiota to stressful condition was employed. Degradation performances were monitored and molecular tools (16S sequencing and ARISA fingerprinting technique) were used to track changes in the microbial community. The acclimation strategy progressively minimized the effect of phenol on degradation performances. After 3 successive disturbance episodes, microbiota resistance was considerably developed and total inhibition threshold increased from 895 to 1942mg/L of phenol. Microbiota adaptation was characterized by the selection of the most resistant Archaea OTU from Methanobacterium genus and an important elasticity of Bacteria, especially within Clostridiales and Bacteroidales orders, that probably enabled the adaptation to more and more stressful conditions. PMID:27233100

  14. Influent Fractionation for Modeling Continuous Anaerobic Digestion Processes.

    PubMed

    Lübken, Manfred; Kosse, Pascal; Koch, Konrad; Gehring, Tito; Wichern, Marc

    2015-01-01

    The first dynamic model developed to describe anaerobic digestion processes dates back to 1969. Since then, considerable improvements in identifying the underlying biochemical processes and associated microorganisms have been achieved. These have led to an increasing complexity of both model structure and the standard set of stoichiometric and kinetic parameters. Literature has always paid attention to kinetic parameter estimation, as this determines model accuracy with respect to predicting the dynamic behavior of biogas systems. As sufficient computing power is easily available nowadays, sophisticated linear and nonlinear parameter estimation techniques are applied to evaluate parameter uncertainty. However, the uncertainty of influent fractionation in these parameter optimization procedures is generally neglected. As anaerobic digestion systems are currently increasingly used to convert a broad variety of organic biomass to methane, the lack of generally accepted guidelines for input characterization adapted to the simulation model's characteristics is a considerable limitation of model application to these substrates. Directly after the introduction of the standardized Anaerobic Digestion Model No. 1 (ADM1), several publications pointed out that the model's requirement of a detailed influent characterization can hardly be fulfilled. The main shortcoming of the model application was addressed in the reliable and practical identification of the model's input state variables for particulate and soluble carbohydrates, proteins and lipids, as well as for the inerts. Several authors derived biomass characterization procedures, most of them dedicated to a particular substrate, and some of them being of general nature, but none of these approaches have resulted in a practical standard protocol so far. This review provides an overview of existing approaches that improve substrate influent characterization to be used for state of the art anaerobic digestion models. PMID

  15. Material and method for promoting the growth of anaerobic bacteria

    DOEpatents

    Adler, H.I.

    1984-10-09

    A material and method is disclosed for promoting the growth of anaerobic bacteria which includes a nutrient media containing a hydrogen donor and sterile membrane fragments of bacteria having an electron transfer system which reduces oxygen to water. Dissolved oxygen in the medium is removed by adding the sterile membrane fragments to the nutrient medium and holding the medium at a temperature of about 10 to about 60 C until the dissolved oxygen is removed. No Drawings

  16. Material and method for promoting the growth of anaerobic bacteria

    DOEpatents

    Adler, Howard I.

    1984-01-01

    A material and method for promoting the growth of anaerobic bacteria which includes a nutrient media containing a hydrogen donor and sterile membrane fragments of bacteria having an electron transfer system which reduces oxygen to water. Dissolved oxygen in the medium is removed by adding the sterile membrane fragments to the nutrient medium and holding the medium at a temperature of about 10.degree. to about 60.degree. C. until the dissolved oxygen is removed.

  17. pmoA Primers for Detection of Anaerobic Methanotrophs▿

    PubMed Central

    Luesken, Francisca A.; Zhu, Baoli; van Alen, Theo A.; Butler, Margaret K.; Diaz, Marina Rodriguez; Song, Bongkeun; Op den Camp, Huub J. M.; Jetten, Mike S. M.; Ettwig, Katharina F.

    2011-01-01

    Published pmoA primers do not match the pmoA sequence of “Candidatus Methylomirabilis oxyfera,” a bacterium that performs nitrite-dependent anaerobic methane oxidation. Therefore, new pmoA primers for the detection of “Ca. Methylomirabilis oxyfera”-like methanotrophs were developed and successfully tested on freshwater samples from different habitats. These primers expand existing molecular tools for the study of methanotrophs in the environment. PMID:21460105

  18. Specificity of aerobic and anaerobic work capacities and powers.

    PubMed

    Boulay, M R; Lortie, G; Simoneau, J A; Hamel, P; Leblanc, C; Bouchard, C

    1985-12-01

    Thirty-three untrained subjects of both sexes, 18-31 years of age, performed several tests on cycle ergometers. Maximal aerobic power (MAP) was obtained in a progressive work test. Maximal aerobic capacity (MAC) was measured in a 90-min maximal test and was computed as the total work output during that period. Two all-out cycle ergometer work tests lasting 10 s and 90 s were used to estimate the anaerobic alactic capacity (AAC) and lactic capacity (ALC). Anaerobic alactic power (AAP) was computed as the highest output in 1 s in the AAC test and anaerobic lactic power (ALP) was obtained as the mean output during the last 5 s in an all-out test of 30 s. Correlation coefficients were computed between all measurements of capacity and power expressed per kg of body weight as well as with scores adjusted for sex differences. Common variances (r2 X 100) between measurements of power were either low (MAP-AAP, 40%) or moderate (MAP-ALP, 61%; AAP-ALP, 62%) while common variances between measurements of capacity were sometimes low (MAC-AAC, 49%) or higher (MAC-ALC, 76%; AAC-ALC, 77%). The common variances between tests of power and capacity reached high values when calculated with metabolic criteria of the same class (MAP-MAC, 81%; AAP-AAC, 92%). These results provide quantitative evidence to support the notion of specificity between the aerobic and the anaerobic work performances and support the distinction between capacity and power of the three energy systems. PMID:4077360

  19. A bio-hybrid anaerobic treatment of papaya processing wastes

    SciTech Connect

    Yang, P.Y.; Chou, C.Y.

    1987-01-01

    Hybrid anaerobic treatment of papaya processing wastes is technically feasible. At 30/sup 0/C, the optimal organic loading rates for maximizing organic removal efficiency and methane production are 1.3 and 4.8 g TCOD/1/day, respectively. Elimination of post-handling and treatment of digested effluent can also be achieved. The system is more suitable for those processing plants with a waste amount of more than 3,000 metric tons per year.

  20. Metagenome of an Anaerobic Microbial Community Decomposing Poplar Wood Chips

    SciTech Connect

    van der Lelie, D.; Taghavi, S.; McCorkle, S. M.; Li, L. L.; Malfatti, S. A.; Monteleone, D.; Donohoe, B. S.; Ding, S. Y.; Adney, W. S.; Himmel, M. E.; Tringe, S. G.

    2012-05-01

    This study describes the composition and metabolic potential of a lignocellulosic biomass degrading community that decays poplar wood chips under anaerobic conditions. We examined the community that developed on poplar biomass in a non-aerated bioreactor over the course of a year, with no microbial inoculation other than the naturally occurring organisms on the woody material. The composition of this community contrasts in important ways with biomass-degrading communities associated with higher organisms, which have evolved over millions of years into a symbiotic relationship. Both mammalian and insect hosts provide partial size reduction, chemical treatments (low or high pH environments), and complex enzymatic 'secretomes' that improve microbial access to cell wall polymers. We hypothesized that in order to efficiently degrade coarse untreated biomass, a spontaneously assembled free-living community must both employ alternative strategies, such as enzymatic lignin depolymerization, for accessing hemicellulose and cellulose and have a much broader metabolic potential than host-associated communities. This would suggest that such a community would make a valuable resource for finding new catalytic functions involved in biomass decomposition and gaining new insight into the poorly understood process of anaerobic lignin depolymerization. Therefore, in addition to determining the major players in this community, our work specifically aimed at identifying functions potentially involved in the depolymerization of cellulose, hemicelluloses, and lignin, and to assign specific roles to the prevalent community members in the collaborative process of biomass decomposition. A bacterium similar to Magnetospirillum was identified among the dominant community members, which could play a key role in the anaerobic breakdown of aromatic compounds. We suggest that these compounds are released from the lignin fraction in poplar hardwood during the decay process, which would point to

  1. Anaerobic Endurance of Young Untrained Male and Female Subjects

    ERIC Educational Resources Information Center

    Sienkiewicz-Dianzenza, Edyta; Tomaszewski, Pawel; Iwanska, Dagmara; Stupnicki, Romuald

    2009-01-01

    Study aim: To assess the anaerobic endurance of untrained male and female subjects by applying repeated maximal exercises. Material and methods: Untrained male subjects aged 23-27 years (n = 17, body height 170-197 cm, body mass 65-110 kg) and female ones aged 20-25 years (n = 10, body height 168-184 cm, body mass 55-86 kg) performed 6 maximal…

  2. Natural attenuation of xenobiotic compounds: Anaerobic field injection experiment

    SciTech Connect

    Ruegge, K.; Bjerg, P.L.; Mosbaek, H.; Christensen, T.H.

    1995-12-31

    Currently, a continuous field injection experiment is being performed in the anaerobic part of a pollution plume downgradient of the Grindsted Landfill in Denmark. This natural gradient experiment includes an injection of 18 different xenobiotic compounds with bromide as a tracer. The injection is taking place under methanogenic/sulfate-reducing conditions and the compounds will, as they migrate with the groundwater, pass through a zone where the redox conditions have been determined as iron-reducing.

  3. Biomass selection for optimal anaerobic treatment of olive mill wastewater.

    PubMed

    Sabbah, I; Yazbak, A; Haj, J; Saliba, A; Basheer, S

    2005-01-01

    This research was conducted to identify the most efficient biomass out of five different types of biomass sources for anaerobic treatment of Olive Mill Wastewater (OMW). This study was first focused on examining the selected biomass in anaerobic batch systems with sodium acetate solutions (control study). Then, the different types of biomass were tested with raw OMW (water-diluted) and with pretreated OMW by coagulation-flocculation using Poly Aluminum Chloride (PACl) combined with hydrated lime (Ca(OH)2). Two types of biomass from wastewater treatment systems of a citrus juice producing company "PriGat" and from a citric acid manufacturing factory "Gadot", were found to be the most efficient sources of microorganisms to anaerobically treat both sodium acetate solution and OMW. Both types of biomass were examined under different concentration ranges (1-40 g l(-1)) of OMW in order to detect the maximal COD tolerance for the microorganisms. The results show that 70-85% of COD removal was reached using Gadot biomass after 8-10 days when the initial concentration of OMW was up to 5 g l(-1), while a similar removal efficiency was achieved using OMW of initial COD concentration of 10 g l(-1) in 2-4 days of contact time with the PriGat biomass. The physico-chemical pretreatment of OMW was found to enhance the anaerobic activity for the treatment of OMW with initial concentration of 20 g l(-1) using PriGat biomass. This finding is attributed to reducing the concentrations of polyphenols and other toxicants originally present in OMW upon the applied pretreatment process. PMID:15747599

  4. Anaerobic biological treatment of in-situ retort water

    SciTech Connect

    Ossio, E.; Fox, P.

    1980-03-01

    Anaerobic fermentation was successfully used in a laboratory-scale batch digester to remove soluble organics from retort water. Required pretreatment includes reduction of ammonia levels to 360 mg-N/l, pH adjustment to 7.0, sulfide control, and the addition of the nutrients, calcium, magnesium, and phoshorus. If the prescribed pretreatment is used, BOD/sub 5/ and COD removal efficiencies of 89 to 90% and 65 to 70% are achieved, respectively.

  5. Single stage anaerobic digester at Tarleton State University. Final report

    SciTech Connect

    Not Available

    1980-01-01

    The design and operation of the demonstration plant facilities at Tarleton State University to produce methane in a single stage anaerobic digester are described. A combination of manures from hogs and poultry are used as feedstock. Uses for the methane, cost of the digester, and value of the energy produced are discussed. During the 21 months of operation, 310 people have visited the project. (DMC)

  6. Treatment of melanoidin wastewater by anaerobic digestion and coagulation.

    PubMed

    Arimi, Milton M; Zhang, Yongjun; Götz, Gesine; Geißen, Sven-Uwe

    2015-01-01

    Melanoidins are dark-coloured recalcitrant pollutants found in many industrial wastewaters including coffee-manufacturing effluent, molasses distillery wastewater (MDWW) and other wastewater with molasses as the raw material. The wastewaters are mostly treated with anaerobic digestion after some dilution to minimize the inhibition effect. However, the dark colour and recalcitrant dissolved organic carbon (DOC) mainly caused by melanoidin are not effectively removed. The aim of this study was to investigate the removal of colour and remnant DOC by different coagulants from anaerobically digested MDWW. From the six coagulants tested, ferric chloride had the highest melanoidin (48%), colour (92.7%) and DOC (63.3%) removal at pH 5 and a dosage of 1.6 g/l. Both polymer and inorganic salt coagulants tested had optimal colour, melanoidin and DOC removal at acidic pH. The molecular size distribution of synthetic melanoidins by liquid chromatography-organic carbon detection indicated a preferential removal of high-molecular-weight melanoidins over low weight melanoidins by the coagulation. Further studies should focus on how to improve biodegradability of the treated effluent for it to be reused as dilution water for anaerobic digestion. PMID:25799161

  7. Continuous biohydrogen production from waste bread by anaerobic sludge.

    PubMed

    Han, Wei; Huang, Jingang; Zhao, Hongting; Li, Yongfeng

    2016-07-01

    In this study, continuous biohydrogen production from waste bread by anaerobic sludge was performed. The waste bread was first hydrolyzed by the crude enzymes which were generated by Aspergillus awamori and Aspergillus oryzae via solid-state fermentation. It was observed that 49.78g/L glucose and 284.12mg/L free amino nitrogen could be produced with waste bread mass ratio of 15% (w/v). The waste bread hydrolysate was then used for biohydrogen production by anaerobic sludge in a continuous stirred tank reactor (CSTR). The optimal hydrogen production rate of 7.4L/(Ld) was achieved at chemical oxygen demand (COD) of 6000mg/L. According to the results obtained from this study, 1g waste bread could generate 0.332g glucose which could be further utilized to produce 109.5mL hydrogen. This is the first study which reports continuous biohydrogen production from waste bread by anaerobic sludge. PMID:27065225

  8. Ultrasonic waste activated sludge disintegration for improving anaerobic stabilization.

    PubMed

    Tiehm, A; Nickel, K; Zellhorn, M; Neis, U

    2001-06-01

    The pretreatment of waste activated sludge by ultrasonic disintegration was studied in order to improve the anaerobic sludge stabilization. The ultrasound frequency was varied within a range from 41 to 3217 kHz. The impact of different ultrasound intensities and treatment times was examined. Sludge disintegration was most significant at low frequencies. Low-frequency ultrasound creates large cavitation bubbles which upon collapse initiate powerful jet streams exerting strong shear forces in the liquid. The decreasing sludge disintegration efficiency observed at higher frequencies was attributed to smaller cavitation bubbles which do not allow the initiation of such strong shear forces. Short sonication times resulted in sludge floc deagglomeration without the destruction of bacteria cells. Longer sonication brought about the break-up of cell walls, the sludge solids were distintegrated and dissolved organic compounds were released. The anaerobic digestion of waste activated sludge following ultrasonic pretreatment causing microbial cell lysis was significantly improved. There was an increase in the volatile solids degradation as well as an increase in the biogas production. The increase in digestion efficiency was proportional to the degree of sludge disintegration. To a lesser degree the deagglomeration of sludge flocs also augmented the anaerobic volatile solids degradation. PMID:11337847

  9. Gender difference in anaerobic capacity: role of aerobic contribution.

    PubMed Central

    Hill, D W; Smith, J C

    1993-01-01

    The purpose of this study was to evaluate effects of gender on anaerobic and aerobic contributions to high-intensity exercise. A group of 38 subjects (22 women, 16 men) performed modified Wingate tests against resistances of 0.086 kg kg-1 body mass (0.844 N kg-1) for women and 0.095 kg kg-1 body mass (0.932 N kg-1) for men. The aerobic contribution to total work performed was determined from breath-by-breath analyses of expired gases during each test. Total work in 30 s was 30% lower (Student's t test; P < 0.01) in women than men (211 +/- 5 J kg-1 versus 299 +/- 14 J kg-1). Aerobic contribution was only 7% lower (P = 0.12) in women than men (53 +/- 1 J kg-1 versus 57 +/- 2 J kg-1). The anaerobic component of the work performed, determined by subtraction of the aerobic component from total work in 30 s, was 35% lower (P < 0.01) in women than men (158 +/- 5 J kg-1 versus 242 +/- 15 J kg-1). It is concluded that, because women provide a relatively higher (P < 0.01) portion of the energy for a 30-s test aerobically than men (25% versus 20%), total work during a Wingate test actually underestimates the gender difference in anaerobic capacity between women and men. PMID:8457813

  10. Anaerobic biodegradability of fish remains: experimental investigation and parameter estimation.

    PubMed

    Donoso-Bravo, Andres; Bindels, Francoise; Gerin, Patrick A; Vande Wouwer, Alain

    2015-01-01

    The generation of organic waste associated with aquaculture fish processing has increased significantly in recent decades. The objective of this study is to evaluate the anaerobic biodegradability of several fish processing fractions, as well as water treatment sludge, for tilapia and sturgeon species cultured in recirculated aquaculture systems. After substrate characterization, the ultimate biodegradability and the hydrolytic rate were estimated by fitting a first-order kinetic model with the biogas production profiles. In general, the first-order model was able to reproduce the biogas profiles properly with a high correlation coefficient. In the case of tilapia, the skin/fin, viscera, head and flesh presented a high level of biodegradability, above 310 mLCH₄gCOD⁻¹, whereas the head and bones showed a low hydrolytic rate. For sturgeon, the results for all fractions were quite similar in terms of both parameters, although viscera presented the lowest values. Both the substrate characterization and the kinetic analysis of the anaerobic degradation may be used as design criteria for implementing anaerobic digestion in a recirculating aquaculture system. PMID:25812103

  11. Biohydrogenation of C20 polyunsaturated fatty acids by anaerobic bacteria.

    PubMed

    Sakurama, Haruko; Kishino, Shigenobu; Mihara, Kousuke; Ando, Akinori; Kita, Keiko; Takahashi, Satomi; Shimizu, Sakayu; Ogawa, Jun

    2014-09-01

    The PUFAs include many bioactive lipids. The microbial metabolism of C18 PUFAs is known to produce their bioactive isomers, such as conjugated FAs and hydroxy FAs, but there is little information on that of C20 PUFAs. In this study, we aimed to obtain anaerobic bacteria with the ability to produce novel PUFAs from C20 PUFAs. Through the screening of ∼100 strains of anaerobic bacteria, Clostridium bifermentans JCM 1386 was selected as a strain with the ability to saturate PUFAs during anaerobic cultivation. This strain converted arachidonic acid (cis-5,cis-8,cis-11,cis-14-eicosatetraenoic acid) and EPA (cis-5,cis-8,cis-11,cis-14,cis-17-EPA) into cis-5,cis-8,trans-13-eicosatrienoic acid and cis-5,cis-8,trans-13,cis-17-eicosatetraenoic acid, giving yields of 57% and 67% against the added PUFAs, respectively. This is the first report of the isolation of a bacterium transforming C20 PUFAs into corresponding non-methylene-interrupted FAs. We further investigated the substrate specificity of the biohydrogenation by this strain and revealed that it can convert two cis double bonds at the ω6 and ω9 positions in various C18 and C20 PUFAs into a trans double bond at the ω7 position. This study should serve to open up the development of novel potentially bioactive PUFAs. PMID:25002034

  12. Biodegradability and toxicity assessment of bleach plant effluents treated anaerobically.

    PubMed

    Chaparro, T R; Botta, C M; Pires, E C

    2010-01-01

    As part of an experimental project on the treatment of bleach plant effluents the results of biodegradability and toxicity assessment of effluents from a bench-scale horizontal anaerobic immobilized bioreactor (HAIB) are discussed in this paper. The biodegradability of the bleach plant effluents from a Kraft pulp mill treated in the HAIB was evaluated using the modified Zahn-Wellens test. The inoculum came from a pulp mill wastewater treatment plant and the dissolved organic carbon (DOC) was used as the indicator of organic matter removal. The acute and chronic toxicity removal during the anaerobic treatment was estimated using Daphnia similis and Ceriodaphnia silvestrii respectively. Moreover, the evaluation of chromosome aberrations (CA), micronucleus frequencies (MN) and mitotic index (IM) in Allium cepa cells were used as genotoxicity indicators. The results indicate that the effluents from the anaerobic reactor are amenable to aerobic polishing. Acute and chronic toxicity were reduced by 90 and 81%, respectively. The largest CA and MN incidence in the meristematic cells of A. cepa were observed after exposure to the raw bleach plant effluent. The HAIB was able to reduce the acute and chronic toxicity as well as chromosome aberrations and the occurrence of micronucleus. PMID:20861545

  13. Microbial Ecology of Anaerobic Digesters: The Key Players of Anaerobiosis

    PubMed Central

    Ali Shah, Fayyaz; Mahmood, Qaisar; Maroof Shah, Mohammad; Pervez, Arshid; Ahmad Asad, Saeed

    2014-01-01

    Anaerobic digestion is the method of wastes treatment aimed at a reduction of their hazardous effects on the biosphere. The mutualistic behavior of various anaerobic microorganisms results in the decomposition of complex organic substances into simple, chemically stabilized compounds, mainly methane and CO2. The conversions of complex organic compounds to CH4 and CO2 are possible due to the cooperation of four different groups of microorganisms, that is, fermentative, syntrophic, acetogenic, and methanogenic bacteria. Microbes adopt various pathways to evade from the unfavorable conditions in the anaerobic digester like competition between sulfate reducing bacteria (SRB) and methane forming bacteria for the same substrate. Methanosarcina are able to use both acetoclastic and hydrogenotrophic pathways for methane production. This review highlights the cellulosic microorganisms, structure of cellulose, inoculum to substrate ratio, and source of inoculum and its effect on methanogenesis. The molecular techniques such as DGGE (denaturing gradient gel electrophoresis) utilized for dynamic changes in microbial communities and FISH (fluorescent in situ hybridization) that deal with taxonomy and interaction and distribution of tropic groups used are also discussed. PMID:24701142

  14. On-farm anaerobic digester and fuel alcohol plant

    SciTech Connect

    Not Available

    1985-01-01

    An anaerobic digestion system was constructed and set up on a southern Illinois farm. The anaerobic digestion system was designed to be coupled with a fuel alcohol plant constructed by the farm family as part of an integrated farm energy system. The digester heating can be done using waste hot water from the alcohol plant and biogas from the digester can be used as fuel for the alcohol production. The anaerobic digestion system is made up of the following components. A hog finishing house, which already had a slotted floor and manure pit beneath it, was fitted with a system to scrape the manure into a feed slurry pit constructed at one end of the hog house. A solids handling pump feeds the manure from the feed slurry pit into the digester, a 13,000 gallon tank car body which has been insulated with styrofoam and buried underground. Another pump transfers effluent (digested manure) from the digester to a 150,000 gallon storage tank. The digested manure is then applied to cropland at appropriate times of the year. The digester temperature is maintained at the required level by automated hot water circulation through an internal heat exchanger. The biogas produced in the digester is pumped into a 32,000 gallon gas storage tank.

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

    PubMed

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

    2014-01-01

    The objective of this study was to evaluate changes in the microbial population of anaerobic sludge digesters during the adaptation to pig slurry (PS) using quantitative real-time polymerase chain reaction (qPCR) and qualitative scanning electron microscopy (SEM). Additionally, the relationship between microbial parameters and sludge physicochemical composition and methane yield was examined. Results showed that the addition of PS to an unadapted thermophilic anaerobic digester caused an increase in volatile fatty acids (VFA) concentration, a decrease in removal efficiency and CH4 yield. Additionally, increases in total bacteria and total archaea were observed using qPCR. Scanning electron micrographs provided a general overview of the sludge's cell morphology, morphological diversity and degree of organic matter degradation. A change in microbial morphotypes from homogeneous cell morphologies to a higher morphological diversity, similar to that observed in PS, was observed with the addition of PS by SEM. Therefore, the combination of qPCR and SEM allowed expanding the knowledge about the microbial adaptation to animal slurry in thermophilic anaerobic digesters. PMID:24645456

  16. Oxidation and methylation of dissolved elemental mercury by anaerobic bacteria

    NASA Astrophysics Data System (ADS)

    Hu, Haiyan; Lin, Hui; Zheng, Wang; Tomanicek, Stephen J.; Johs, Alexander; Feng, Xinbin; Elias, Dwayne A.; Liang, Liyuan; Gu, Baohua

    2013-09-01

    Methylmercury is a neurotoxin that poses significant health risks to humans. Some anaerobic sulphate- and iron-reducing bacteria can methylate oxidized forms of mercury, generating methylmercury. One strain of sulphate-reducing bacteria (Desulfovibrio desulphuricans ND132) can also methylate elemental mercury. The prevalence of this trait among different bacterial strains and species remains unclear, however. Here, we compare the ability of two strains of the sulphate-reducing bacterium Desulfovibrio and one strain of the iron-reducing bacterium Geobacter to oxidize and methylate elemental mercury in a series of laboratory incubations. Experiments were carried out under dark, anaerobic conditions, in the presence of environmentally relevant concentrations of elemental mercury. We report differences in the ability of these organisms to oxidize and methylate elemental mercury. In line with recent findings, we show that D.desulphuricans ND132 can both oxidize and methylate elemental mercury. We find that the rate of methylation of elemental mercury is about one-third the rate of methylation of oxidized mercury. We also show that Desulfovibrio alaskensis G20 can oxidize, but not methylate, elemental mercury. Geobacter sulphurreducens PCA is able to oxidize and methylate elemental mercury in the presence of cysteine. We suggest that the activity of methylating and non-methylating bacteria may together enhance the formation of methylmercury in anaerobic environments.

  17. Anaerobic Mercury Methylation and Demethylation by Geobacter bemidjiensis Bem

    DOE PAGESBeta

    Lu, Xia; Liu, Yurong; Johs, Alexander; Zhao, Linduo; Wang, Tieshan; Yang, Ziming; Lin, Hui; Elias, Dwayne A.; Pierce, Eric M.; Liang, Liyuan; et al

    2016-03-28

    Two competing processes controlling the net production and bioaccumulation of neurotoxic methylmercury (MeHg) in natural ecosystems are microbial methylation and demethylation. Though mercury (Hg) methylation by anaerobic microorganisms and demethylation by aerobic Hg-resistant bacteria have both been extensively studied, little attention has been given to MeHg degradation by anaerobic bacteria, particularly the iron-reducing bacterium Geobacter bemidjensis Bem. Here we report, for the first time, that the strain G. bemidjensis Bem can methylate inorganic Hg and degrade MeHg concurrently under anoxic conditions. Our results suggest that G. bemidjensis cells utilize a reductive demethylation pathway to degrade MeHg, with elemental Hg(0) asmore » the major reaction product, possibly due to the presence of homologs encoding both organo-mercurial lyase (MerB) and mercuric reductase (MerA) in this organism. In addition, the cells can mediate multiple reactions including Hg/MeHg sorption, Hg reduction and oxidation, resulting in both time and concentration dependent Hg species transformations. Moderate concentrations (10 500 M) of Hg-binding ligands such as cysteine enhance Hg(II) methylation but inhibit MeHg degradation. These findings indicate a cycle of methylation and demethylation among anaerobic bacteria and suggest that mer-mediated demethylation may play a role in the net balance of MeHg production in anoxic water and sediments.« less

  18. Cellulose fermentation by nitrogen-fixing anaerobic bacteria

    SciTech Connect

    Canale-Parola, E.

    1992-12-13

    In anaerobic natural environments cellulose is degraded to methane, carbon dioxide and other products by the combined activities of many diverse microorganisms. We are simulating processes occurring in natural environments by constructing biologically-defined, stable, heterogeneous bacterial communities (consortia) that we use as in vitro systems for quantitative studies of cellulose degradation under conditions of combined nitrogen deprivation. These studies include the investigation of (i) metabolic interactions among members of cellulose-degrading microbial populations, and (ii) processes that regulate the activity or biosynthesis of cellulolytic enzymes. In addition, we are studying the sensory mechanisms that, in natural environments, may enable motile cellulolytic bacteria to migrate toward cellulose. This part of our work includes biochemical characterization of the cellobiose chemoreceptor of cellulolytic bacteria. Finally, an important aspect of our research is the investigation of the mechanisms by which multienzyme complexes of anaerobic bacteria catalyze the depolymerization of crystalline cellulose and of other plant cell wall polysacchaddes. The research will provide fundamental information on the physiology and ecology of cellulose-fermenting, N{sub 2}-fixing bacteria, and on the intricate processes involved in C and N cycling in anaerobic environments. Furthermore, the information will be valuable for the development of practical applications, such as the conversion of plant biomass (e.g., agricultural, forestry and municipal wastes) to automotive fuels such as ethanol.

  19. GC/IR computer-aided identification of anaerobic bacteria

    NASA Astrophysics Data System (ADS)

    Ye, Hunian; Zhang, Feng S.; Yang, Hua; Li, Zhu; Ye, Song

    1993-09-01

    A new method was developed to identify anaerobic bacteria by using pattern recognition. The method is depended on GC / JR data. The system is intended for use as a precise rapid and reproduceable aid in the identification of unknown isolates. Key Words: Anaerobic bacteria Pattern recognition Computeraided identification GC / JR 1 . TNTRODUCTTON A major problem in the field of anaerobic bacteriology is the difficulty in accurately precisely and rapidly identifying unknown isolates. Tn the proceedings of the Third International Symposium on Rapid Methods and Automation in Microbiology C. M. Moss said: " Chromatographic analysis is a new future for clinical microbiology" . 12 years past and so far it seems that this is an idea whose time has not get come but it close. Now two major advances that have brought the technology forword in terms ofmaking it appropriate for use in the clinical laboratory can aldo be cited. One is the development and implementation of fused silica capillary columns. In contrast to packed columns and those of'' greater width these columns allow reproducible recovery of hydroxey fatty acids with the same carbon chain length. The second advance is the efficient data processing afforded by modern microcomputer systems. On the other hand the practical steps for sample preparation also are an advance in the clinical laboratory. Chromatographic Analysis means mainly of analysis of fatty acids. The most common

  20. Aerobic and anaerobic growth of Paracoccus denitrificans on methanol.

    PubMed

    Bamforth, C W; Quayle, J R

    1978-10-01

    1. The dye-linked methanol dehydrogenase from Paracoccus denitrificans grown aerobically on methanol has been purified and its properties compared with similar enzymes from other bacteria. It was shown to be specific and to have high affinity for primary alcohols and formaldehyde as substrate, ammonia was the best activator and the enzyme could be linked to reduction of phenazine methosulphate. 2. Paracoccus denitrificans could be grown anaerobically on methanol, using nitrate or nitrite as electron acceptor. The methanol dehydrogenase synthesized under these conditions could not be differentiated from the aerobically-synthesized enzyme. 3. Activities of methanol dehydrogenase, formaldehyde dehydrogenase, formate dehydrogenase, nitrate reductase and nitrite reductase were measured under aerobic and anaerobic growth conditions. 4. Difference spectra of reduced and oxidized cytochromes in membrane and supernatant fractions of methanol-grown P. denitrificans were measured. 5. From the results of the spectral and enzymatic analyses it has been suggested that anaerobic growth on methanol/nitrate is made possible by reduction of nitrate to nitrite using electrons derived from the pyridine nucleotide-linked dehydrogenations of formaldehyde and formate, the nitrite so produced then functioning as electron acceptor for methanol dehydrogenase via cytochrome c and nitrite reductase. PMID:718372

  1. Factors controlling pathogen destruction during anaerobic digestion of biowastes

    SciTech Connect

    Smith, S.R. . E-mail: s.r.smith@imperial.ac.uk; Lang, N.L.; Cheung, K.H.M.; Spanoudaki, K.

    2005-07-01

    Anaerobic digestion is the principal method of stabilising biosolids from urban wastewater treatment in the UK, and it also has application for the treatment of other types of biowaste. Increasing awareness of the potential risks to human and animal health from environmental sources of pathogens has focused attention on the efficacy of waste treatment processes at destroying pathogenic microorganisms in biowastes recycled to agricultural land. The degree of disinfection achieved by a particular anaerobic digester is influenced by a variety of interacting operational variables and conditions, which can often deviate from the ideal. Experimental investigations demonstrate that Escherichia coli and Salmonella spp. are not damaged by mesophilic temperatures, whereas rapid inactivation occurs by thermophilic digestion. A hydraulic, biokinetic and thermodynamic model of pathogen inactivation during anaerobic digestion showed that a 2 log{sub 10} reduction in E. coli (the minimum removal required for agricultural use of conventionally treated biosolids) is likely to challenge most conventional mesophilic digesters, unless strict maintenance and management practices are adopted to minimise dead zones and by-pass flow. Efficient mixing and organic matter stabilisation are the main factors controlling the rate of inactivation under mesophilic conditions and not a direct effect of temperature per se on pathogenic organisms.

  2. Pulse shear stress for anaerobic membrane bioreactor fouling control.

    PubMed

    Yang, Jixiang; Spanjers, Henri; van Lier, Jules B

    2011-01-01

    Increase of shear stress at membrane surfaces is a generally applied strategy to minimize membrane fouling. It has been reported that a two-phase flow, better known as slug flow, is an effective way to increase shear stress. Hence, slug flow was introduced into an anaerobic membrane bioreactor for membrane fouling control. Anaerobic suspended sludge was cultured in an anaerobic membrane bioreactor (AMBR) operated with a side stream inside-out tubular membrane unit applying sustainable flux flow regimes. The averaged particle diameter decreased from 20 to 5 microm during operation of the AMBR. However, the COD removal efficiency did not show any significant deterioration, whereas the specific methanogenic activity (SMA) increased from 0.16 to 0.41 gCOD/g VSS/day. Nevertheless, the imposed gas slug appeared to be insufficient for adequate fouling control, resulting in rapidly increasing trans membrane pressures (TMP) operating at a flux exceeding 16 L/m2/h. Addition of powdered activated carbon (PAC) enhanced the effect of slug flow on membrane fouling. However, the combined effect was still considered as not being significant. The tubular membrane was subsequently equipped with inert inserts for creating a locally increased shear stress for enhanced fouling control. Results show an increase in the membrane flux from 16 L/m2/h to 34 L/m2/h after the inserts were mounted in the membrane tube. PMID:22097007

  3. [Municipal biowaste thermal-hydrolysis and ASBR anaerobic digestion].

    PubMed

    Hou, Hua-hua; Wang, Wei; Hu, Song; Xu, Yi-xian

    2010-02-01

    Thermal-hydrolysis can remarkably improve the solid organics dissolving efficiency of urban biomass waste, and anaerobic sequencing batch reactor (ASBR) was used to improve the efficiency of urban biomass waste anaerobic digestion. The optimum thermal-hydrolysis temperature and holding time was 175 degrees C and 60 min, the volatile suspended solid (VSS) dissolving ratio of kitchen waste, fruit-and-vegetable waste and sludge were 31.3%, 31.9% and 49.7%, respectively. Two ASBR and one continuous-flow stirred tank reactor (CSTR) were started at hydraulic retention time (HRT) = 20 d, COD organic loading rate (OLR) = 3.2-3.6 kg/(m3 x d). The biogas production volumes were 5656 mL/d(A1), 6335 mL/d(A2) and 3 103 mL/d(CSTR), respectively; VSS degradation ratios were 45.3% (A1), 50.87% (A2), 20.81% (CSTR), and the total COD (TCOD) removal rates were 88.1% (A1), 90% (A2), 72.6% (CSTR). In ASBR, organic solid and anaerobic microorganism were remained in the reactor during settling period. When HRT was 20 d, the solid retention time (SRT) was over 130 d, which made ASBR higher efficiency than CSTR. PMID:20391728

  4. Anaerobic treatment of coconut husk liquor for biogas production.

    PubMed

    Leitão, R C; Araújo, A M; Freitas-Neto, M A; Rosa, M F; Santaella, S T

    2009-01-01

    The market for coconut water causes environmental problems as it is one of the major agro-industrial solid wastes in some developing countries. With the aim of reusing the coconut husk, Embrapa developed a system for processing this raw material. During the dewatering stage Coconut Husk Liquor (CHL) is generated with chemical oxygen demand (COD) varying from 60 to 70 g/L due to high concentrations of sugars and tannins. The present study evaluated the feasibility of anaerobic treatment of CHL through Anaerobic Toxicity Assay and the operation of a lab-scale Upflow Anaerobic Sludge Blanket (UASB) reactor. Results showed that CHL can be treated through a UASB reactor operating with an OLR that reaches up to 10 kg/m3.d and that is maintained stable during the whole operation. With this operational condition, the removal efficiency was higher than 80% for COD and approximately 78% for total tannins, and biogas production was 20 m3 of biogas or 130 KWh per m3 of CHL. Seventy-five percent of the biogas composition was methane and toxicity tests demonstrated that CHL was not toxic to the methanogenic consortia. Conversely, increasing the concentration of CHL leads to increased methanogenic activity. PMID:19448321

  5. Anaerobic Digestion of Food Waste-recycling Wastewater

    NASA Astrophysics Data System (ADS)

    Han, Gyuseong; Shin, Seung Gu; Lim, Juntaek; Jo, Minho; Hwang, Seokhwan

    2010-11-01

    Food waste-recycling (FWR) wastewater was evaluated as feedstock for two-stage anaerobic digestion at different hydraulic retention times (HRTs). The FWR wastewater tested contained high concentrations of organic materials and had chemical oxygen demand (COD) >130 g/L and volatile solids (VS) >55 g/L. Two identical two-stage anaerobic digesters were operated to investigate the performance at six HRTs ranging from 10-25 days. In the acidogenic reactor, the total carbohydrate reduction efficiency and volatile fatty acid production dramatically decreased when acidogenic HRT was <2.5 days (i.e., total two-stage HRT = 15 days). High organic removal ratios of 75.5-85.9% for COD and 68.8-83.6% for VS were achieved throughout the two-stage process. Methane production rate of 1.7-3.6 L-gas/L-reactorṡd was observed. These results suggested that two-stage anaerobic process was successful at the laboratory scale with FWR wastewater as feedstock.

  6. Performance of anaerobic granules for degradation of pentachlorophenol.

    PubMed Central

    Wu, W M; Bhatnagar, L; Zeikus, J G

    1993-01-01

    Anaerobic granules degrading pentachlorophenol (PCP) with specific PCP removal activity up to 14.6 mg/g of volatile suspended solids per day were developed in a laboratory-scale anaerobic upflow sludge blanket reactor at 28 degrees C, by using a mixture of acetate, propionate, butyrate, and methanol as the carbon source. The reactor was able to treat synthetic wastewater containing 40 to 60 mg of PCP per liter at a volumetric loading rate of up to 90 mg/liter of reactor volume per day, with a hydraulic retention time of 10.8 to 15 h. PCP removal of more than 99% was achieved. Results of adsorption of PCP by granular biomass indicated that the PCP removal by the granules was due to biodegradation rather than adsorption. A radiotracer assay demonstrated that the PCP-degrading granules mineralized [14C]PCP to 14CH4 and 14CO2. Toxicity test results indicated that syntrophic propionate degraders and acetate-utilizing methanogens were more sensitive to PCP than syntrophic butyrate degraders. The PCP-degrading granules also exhibited a higher tolerance to the inhibition caused by PCP for methane production and degradation of acetate, propionate, and butyrate, compared with anaerobic granules unadapted to PCP. PMID:8434908

  7. Aerobic and anaerobic exercise training in obese adults

    PubMed Central

    Al Saif, Amer; Alsenany, Samira

    2015-01-01

    [Purpose] Obesity is a global health problem and is associated with a multitude of complications. This study was designed to determine changes in cardiopulmonary functions after aerobic and anaerobic exercise training in obese subjects. [Subjects and Methods] Forty obese subjects, whose ages ranged between 18 and 25 years, were divided into 2 equal groups: group A received aerobic exercise training in addition to dietary measures, and group B received anaerobic exercise training for 3 months in addition to dietary measures. Measurements of systolic blood pressure, diastolic blood pressure, heart rate, maximum voluntary ventilation, maximal oxygen consumption, and body mass index were obtained for both groups before and after the exercise program. [Results] The mean body mass index, systolic blood pressure, diastolic blood pressure, heart rate, and maximal oxygen consumption decreased significantly, whereas the mean maximum voluntary ventilation increased significantly after treatment in group A. The mean maximum voluntary ventilation also increased significantly after treatment in group B. There were significant differences between the mean levels of the investigated parameters in groups A and B after treatment. [Conclusion] Aerobic exercise reduces weight and improves cardiopulmonary fitness in obese subjects better than anaerobic exercise. PMID:26180300

  8. Effect of ultrasonication on anaerobic degradability of solid waste digestate.

    PubMed

    Boni, M R; D'Amato, E; Polettini, A; Pomi, R; Rossi, A

    2016-02-01

    This paper evaluates the effect of ultrasonication on anaerobic biodegradability of lignocellulosic residues. While ultrasonication has been commonly applied as a pre-treatment of the feed substrate, in the present study a non-conventional process configuration based on recirculation of sonicated digestate to the biological reactor was evaluated at the lab-scale. Sonication tests were carried out at different applied energies ranging between 500 and 50,000kJ/kg TS. Batch anaerobic digestion tests were performed on samples prepared by mixing sonicated and untreated substrate at two different ratios (25:75 and 75:25 w/w). The results showed that when applied as a post-treatment of digestate, ultrasonication can positively affect the yield of anaerobic digestion, mainly due to the dissolution effect of complex organic molecules that have not been hydrolyzed by biological degradation. A good correlation was found between the CH4 production yield and the amount of soluble organic matter at the start of digestion tests. The maximum gain in biogas production was 30% compared to that attained with the unsonicated substrate, which was tentatively related to the type and concentration of the metabolic products. PMID:26586420

  9. Anaerobic transformations of complex organic compounds in subsurface soils

    SciTech Connect

    Proctor, B.L. )

    1988-09-01

    This study was initiated following increased observations of man-made organic chemicals in groundwater. In the US, over 40% of the population depends on groundwater for drinking purposes. Soil is often the receptacle for organic chemicals, and there is a danger that they may reach the groundwater in a toxic form. Once contamination of the soil and vadose water has occurred, the compound may not be detected and/or degraded for decades. Limited, if any, information is available on the biotic-abiotic transformations of complex organic compounds in subsurface soils. The purpose of this study was to determine for each test compound (phenothiazine, 1-chloronaphthalene, 2-trifluoromethyl phenothiazine, 2-chloro-5 trifluoromethyl benzophenone and 2,2{prime},4,4{prime} tetrachlorobiphenyl) the following: (A) the soil sorption capacity for untreated subsurface soil, acid-treated, base-treated, mercuric chloride-treated, and calcium chloride treated subsurface soil; (B) transformation of the test compound in EPA soft water under anaerobic biotic and abiotic conditions; (C) transformation of the test compound in subsurface soils microcosms under anaerobic biotic and abiotic conditions; and (D) comparison of the results form the soil and water anaerobic biotic and abiotic studies.

  10. Integrated anaerobic/aerobic biological treatment for intensive swine production.

    PubMed

    Bortone, Giuseppe

    2009-11-01

    Manure processing could help farmers to effectively manage nitrogen (N) surplus load. Many pig farms have to treat wastewater. Piggery wastewater treatment is a complex challenge, due to the high COD and N concentrations and low C/N ratio. Anaerobic digestion (AD) could be a convenient pre-treatment, particularly from the energetic view point and farm income, but this causes further reduction of C/N ratio and makes denitrification difficult. N removal can only be obtained integrating anaerobic/aerobic treatment by taking into account the best use of electron donors. Experiences gained in Italy during development of integrated biological treatment approaches for swine manure, from bench to full scale, are reported in this paper. Solid/liquid separation as pre-treatment of raw manure is an efficient strategy to facilitate liquid fraction treatment without significantly lowering C/N ratio. In Italy, two full scale SBRs showed excellent efficiency and reliability. Current renewable energy policy and incentives makes economically attractive the application of AD to the separated solid fraction using high solid anaerobic digester (HSAD) technology. Economic evaluation showed that energy production can reduce costs up to 60%, making sustainable the overall treatment. PMID:19135363

  11. [Agroindustrial wastes methanization and bacterial composition in anaerobic digestion].

    PubMed

    González-Sánchez, María E; Pérez-Fabiel, Sergio; Wong-Villarreal, Arnoldo; Bello-Mendoza, Ricardo; Yañez-Ocampo, Gustavo

    2015-01-01

    The tons of organic waste that are annually generated by agro-industry, can be used as raw material for methane production. For this reason, it is important to previously perform biodegradability tests to organic wastes for their full scale methanization. This paper addresses biodegradability, methane production and the behavior of populations of eubacteria and archaeabacteria during anaerobic digestion of banana, mango and papaya agroindustrial wastes. Mango and banana wastes had higher organic matter content than papaya in terms of their volatile solids and total solid rate (94 and 75% respectively). After 63 days of treatment, the highest methane production was observed in banana waste anaerobic digestion: 63.89ml CH4/per gram of chemical oxygen demand of the waste. In the PCR-DGGE molecular analysis, different genomic footprints with oligonucleotides for eubacteria and archeobacteria were found. Biochemical methane potential results proved that banana wastes have the best potential to be used as raw material for methane production. The result of a PCR- DGGE analysis using specific oligonucleotides enabled to identify the behavior of populations of eubacteria and archaeabacteria present during the anaerobic digestion of agroindustrial wastes throughout the process. PMID:26365369

  12. A novel mode of lactate metabolism in strictly anaerobic bacteria.

    PubMed

    Weghoff, Marie Charlotte; Bertsch, Johannes; Müller, Volker

    2015-03-01

    Lactate is a common substrate for major groups of strictly anaerobic bacteria, but the biochemistry and bioenergetics of lactate oxidation is obscure. The high redox potential of the pyruvate/lactate pair of E0 ' = -190 mV excludes direct NAD(+) reduction (E0 ' = -320 mV). To identify the hitherto unknown electron acceptor, we have purified the lactate dehydrogenase (LDH) from the strictly anaerobic, acetogenic bacterium Acetobacterium woodii. The LDH forms a stable complex with an electron-transferring flavoprotein (Etf) that exhibited NAD(+) reduction only when reduced ferredoxin (Fd(2-) ) was present. Biochemical analyses revealed that the LDH/Etf complex of A. woodii uses flavin-based electron confurcation to drive endergonic lactate oxidation with NAD(+) as oxidant at the expense of simultaneous exergonic electron flow from reduced ferredoxin (E0 ' ≈ -500 mV) to NAD(+) according to: lactate + Fd(2-)  + 2 NAD(+)  → pyruvate + Fd + 2 NADH. The reduced Fd(2-) is regenerated from NADH by a sequence of events that involves conversion of chemical (ATP) to electrochemical ( Δ μ ˜ Na + ) and finally redox energy (Fd(2-) from NADH) via reversed electron transport catalysed by the Rnf complex. Inspection of genomes revealed that this metabolic scenario for lactate oxidation may also apply to many other anaerobes. PMID:24762045

  13. Denitrification in anaerobic digesters: A review of recent studies

    SciTech Connect

    Akunna, J.C.

    1996-11-01

    Wastewaters from food processing industries (and domestic activities) are usually treated principally for organic carbon removal. But recent standards have generated interests in nitrogen and phosphorus removal. This has led to the addition of nitrification, denitrification and phosphorus removal units in the existing treatment plants, thus increasing the cost of treatment operations. The need to reduce treatment costs has led to research on ways to carry out many treatment processes in a single system. One of these systems consists of anaerobic and aerobic units in series with effluent recycle. In the anaerobic unit, anaerobic digestion and denitrification take place simultaneously producing methane and nitrogen gas while in the aerobic unit, ammonia oxidation to nitrate (nitrification) takes place. This process configuration appears to give lesser problems associated with operations such as the addition of raw wastewater or external organic carbon to ensure complete denitrification. In this paper a review of the results of recent studies are presented, with special emphasis on the factors affecting treatment efficiencies (i.e., denitrification, ammonia production from nitrate, and methane production efficiencies).

  14. Full scale field demonstration of unheated anaerobic contact stabilization

    SciTech Connect

    Sykes, R.M.; Fan, K.S.

    1983-09-01

    A full scale field demonstration of unheated anaerobic digestion, including both solids recycle and solids nonrecycle processes, was conducted at the Jackson Pike Wastewater Treatment Plant at Columbus, Ohio. Two digesters (locally called Tanks 4E and 6E) at this facility were used for this purpose. In the experimental system, the operating temperature was reduced gradually from 91/sup 0/F to 63/sup 0/F. There were eight periods in the Recycle Phase and four periods in the Nonrecycle Phase. Gas production, solids destruction, volatile fatty acid variation, alkalinity, and pH were monitored in each period. In addition, grease, long-chain fatty acids, and foaming were intensively investigated at the last two periods, C and D, of the Nonrecycle Phase. The objectives of this research were: (1) evaluation of the unheated anaerobic digestion in full scale field units, and (2) and development of criteria for design and operation of a cold anaerobic digester. 48 references, 41 figures, 84 tables.

  15. Anaerobic oxidation of cholesterol by a denitrifying enrichment.

    PubMed

    Barrandeguy, E; Tarlera, S

    2001-01-01

    Sterols (e.g. cholesterol) present in wool scouring effluent represent the most recalcitrant fraction in anaerobic treatment. This study was conducted to examine the feasibility of removal of this organic load through a denitrifying post-treatment stage. A stable cholesterol-denitrifying enrichment (CHOL-1) was obtained from sludge of a bench-scale upflow sludge bed (USB) denitrifying reactor integrated to a carbon and nitrogen removal system for sanitary landfill leachate. According to the amounts of cholesterol degraded and of nitrite and nitrogen gas formed, the capacity for complete cholesterol oxidation under anaerobic conditions by CHOL-1 can be assumed. Nitrite accumulation observed at a low C/N ratio outlines the importance of determining the optimal C/N ratio for adequate denitrifying reactor performance. The enrichment was partly identified with molecular analysis of cloned 16S rDNA sequences revealing the presence of two groups of bacteria belonging to the beta subclass of the Proteobacteria. According to analysis of sequences, it can be inferred that a yet uncultivated new bacterium is the one responsible for cholesterol oxidation. Results of this study suggest that sludge from a denitrifying reactor treating leachate is potentially useful in a combined anaerobic-anoxic system for degradation of cholesterol that remains after methanogenic treatment. PMID:11575077

  16. Anaerobic treatment of natural tannin extracts in UASB reactors.

    PubMed

    López-Fluza, J; Omil, F; Méndez, R

    2003-01-01

    Tannin extracts are substances commonly used in leather production processes. Since most of the steps of tannery manufacturing processes are carried out in aqueous environments, the presence of these compounds in the wastewaters is important. The aim of this work is to study the feasibility of the anaerobic degradation of three natural tannin extracts in three Upflow Anaerobic Sludge Blanket (UASB) reactors, which were fed with increasing concentrations of two condensed (quebracho and wattle) and one hydrolysable tannin extract (chestnut). Concentrations of applied extracts were 100, 200, 400, 800 and 1,000 mg/l, and 5 g/l of glucose was used as cosubstrate. Reactors were operated during 210 days and their performance was evaluated from the values of total and soluble COD, total and intermediate alkalinity, volatile fatty acids, pH and UV absorption at 280 nm. COD removal efficiencies higher than 85% were achieved in all cases. However, tannin extract removal efficiencies (based on UV-280 nm absorption measurements) were significantly lower, around 20% for condensed extracts and 60% for the hydrolysable one, when the reactors operated with the highest tannin extract concentration. The operation of the reactors was stable, commonly with alkalinity ratios below 0.30. Mass balances carried out indicate that most of the COD removal efficiencies are due to the removal of the readily biodegradable organic matter (glucose), whereas the tannin extracts are hardly anaerobically biodegradable, especially condensed extracts (wattle and quebracho). PMID:14640213

  17. Reduction of Nitrated Diphenylamine Derivatives under Anaerobic Conditions

    PubMed Central

    Drzyzga, O.; Schmidt, A.; Blotevogel, K.

    1995-01-01

    2-Nitrodiphenylamine, 4-nitrodiphenylamine, and 2,4-dinitrodiphenylamine were anaerobically metabolized in sediment-water batch enrichments inoculated with mud from the German North Sea coast. The first intermediate in 2,4-dinitrodiphenylamine degradation was 2-amino-4-nitrodiphenylamine, which appeared in large (nearly stoichiometric) amounts before being completely reduced to 2,4-diaminodiphenylamine. Of the second theoretically expected metabolite, 4-amino-2-nitrodiphenylamine, only traces were detected by gas chromatographic-mass spectrometric analysis in highly concentrated extracts. In addition, low levels of 4-nitrodiphenylamine, which may be the product of ortho deamination of intermediately produced 2-amino-4-nitrodiphenylamine, were observed. 2-Nitrodiphenylamine and 4-nitrodiphenylamine were primarily reduced to 2-aminodiphenylamine and 4-aminodiphenylamine, respectively. Diphenylamine was never detected in any experiment as a theoretically possible intermediate. Results from studies with dense cell suspensions of anaerobic, aromatic-compound-mineralizing bacteria confirmed the transformation reactions, which were carried out by microorganisms indigenous to the anaerobic coastal water sediment. PMID:16535118

  18. Oxidation and methylation of dissolved elemental mercury by anaerobic bacteria

    SciTech Connect

    Hu, Haiyan; Lin, Hui; Zheng, Wang; Tomanicek, Stephen J; Johs, Alexander; Feng, Xinbin; Elias, Dwayne A; Liang, Liyuan; Gu, Baohua

    2013-08-04

    Methylmercury is a neurotoxin that poses significant health risks to humans. Some anaerobic sulphate- and iron-reducing bacteria can methylate oxidized forms of mercury, generating methylmercury1-4. One strain of sulphate-reducing bacteria (Desulfovibrio desulfuricans ND132) can also methylate elemental mercury5. The prevalence of this trait among different bacterial strains and species remains unclear, however. Here, we compare the ability of two strains of the sulphate-reducing bacterium Desulfovibrio and one strain of the iron-reducing bacterium Geobacter to oxidise and methylate elemental mercury in a series of laboratory incubations. Experiments were carried out under dark, anaerobic conditions, in the presence of environmentally-relevant concentrations of elemental mercury. We report differences in the ability of these organisms to oxidise and methylate elemental mercury. In line with recent findings5, we show that Desulfovibrio desulfuricans ND132 can both oxidise and methylate elemental mercury. However, the rate of methylation of elemental mercury is only about one third the rate of methylation of oxidized mercury. We also show that Desulfovibrio alaskensis G20 can oxidise, but not methylate, elemental mercury. Geobacter sulfurreducens PCA is able to oxidise and methylate elemental mercury in the presence of cysteine. We suggest that the activity of methylating and non-methylating bacteria may together enhance the formation of methylmercury in anaerobic environments.

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

    PubMed

    Aydin, Sevcan; Ince, Bahar; Ince, Orhan

    2016-05-01

    This study evaluated the link between anaerobic bacterial diversity and, the biodegradation of antibiotic combinations and assessed how amending antibiotic combination and increasing concentration of antibiotics in a stepwise fashion influences the development of resistance genes in anaerobic reactors. The biodegradation, sorption and occurrence of the known antibiotic resistance genes (ARGs) of erythromycin and tetracycline were investigated using the processes of UV-HPLC and qPCR analysis respectively. Ion Torrent sequencing was used to detect microbial community changes in response to the addition of antibiotics. The overall results indicated that changes in the structure of a microbial community lead to changes in biodegradation capacity, sorption of antibiotics combinations and occurrence of ARGs. The enhanced biodegradation efficiency appeared to generate variations in the structure of the bacterial community. The results suggested that controlling the ultimate Gram-negative bacterial community, especially Acinetobacter-related populations, may promote the successful biodegradation of antibiotic combinations and reduce the occurrence of ARGs. PMID:26897411

  20. Ultrasonic cell disruption of stabilised sludge with subsequent anaerobic digestion.

    PubMed

    Onyeche, T I; Schläfer, O; Bormann, H; Schröder, C; Sievers, M

    2002-05-01

    The world-wide increasing environmental awareness and its subsequent regulations have led to the application of improved technologies in wastewater purification plants. This has resulted in higher wastewater and sludge productions. Sludge is the by-product of such plants and it is not only rich in organic carbon and pathogens but also in heavy metals and other environmental pollutants. In Europe, agricultural application of dried sludge (bio-solids) is confronted with negative reactions from the citizens, governmental organisations, farmers and the food industry. Ultrasonic disruption of sludge is a popular mechanical disruption process in sludge treatment. During ultrasonic treatment, high frequency acoustic signals are used to initiate the cavitation process. The applied ultrasonic field leads to a breakdown of cohesive forces of the liquid molecules resulting in the generation of cavitation bubbles. A shock wave is released by the collapse of the cavitation bubbles and propagates in the surrounding medium forming jet streams that cause the disruption of cells in sludge. Disruption of sludge cells enables the release of light organic substances into the sludge water thereby exposing them for further anaerobic digestion. This paper presents results on the disruption of conventionally stabilised sludge through the application of the ultrasonic field. In order to reduce the specific energy input (i.e. ratio of the consumed energy during ultrasonic disruption to the input sludge mass) and improve biogas production, the total solids content of the stabilised sludge was increased before disruption. The anaerobic digestion of sludge samples was carried out in a set of specially constructed laboratory anaerobic digesters. Results showed that subsequent anaerobic digestion of the ultrasonically disrupted sludge could improve biogas production with reduced sludge quantity that is vital to the economic consideration of the wastewater treatment plants. This process

  1. Drug Targets and Mechanisms of Resistance in the Anaerobic Protozoa

    PubMed Central

    Upcroft, Peter; Upcroft, Jacqueline A.

    2001-01-01

    The anaerobic protozoa Giardia duodenalis, Trichomonas vaginalis, and Entamoeba histolytica infect up to a billion people each year. G. duodenalis and E. histolytica are primarily pathogens of the intestinal tract, although E. histolytica can form abscesses and invade other organs, where it can be fatal if left untreated. T. vaginalis infection is a sexually transmitted infection causing vaginitis and acute inflammatory disease of the genital mucosa. T. vaginalis has also been reported in the urinary tract, fallopian tubes, and pelvis and can cause pneumonia, bronchitis, and oral lesions. Respiratory infections can be acquired perinatally. T. vaginalis infections have been associated with preterm delivery, low birth weight, and increased mortality as well as predisposing to human immunodeficiency virus infection, AIDS, and cervical cancer. All three organisms lack mitochondria and are susceptible to the nitroimidazole metronidazole because of similar low-redox-potential anaerobic metabolic pathways. Resistance to metronidazole and other drugs has been observed clinically and in the laboratory. Laboratory studies have identified the enzyme that activates metronidazole, pyruvate:ferredoxin oxidoreductase, to its nitroso form and distinct mechanisms of decreasing drug susceptibility that are induced in each organism. Although the nitroimidazoles have been the drug family of choice for treating the anaerobic protozoa, G. duodenalis is less susceptible to other antiparasitic drugs, such as furazolidone, albendazole, and quinacrine. Resistance has been demonstrated for each agent, and the mechanism of resistance has been investigated. Metronidazole resistance in T. vaginalis is well documented, and the principal mechanisms have been defined. Bypass metabolism, such as alternative oxidoreductases, have been discovered in both organisms. Aerobic versus anaerobic resistance in T. vaginalis is discussed. Mechanisms of metronidazole resistance in E. histolytica have recently

  2. Global Gene Expression Profiles of Bacillus subtilis Grown under Anaerobic Conditions

    PubMed Central

    Ye, Rick W.; Tao, Wang; Bedzyk, Laura; Young, Thomas; Chen, Mario; Li, Liao

    2000-01-01

    Bacillus subtilis can grow under anaerobic conditions, either with nitrate or nitrite as the electron acceptor or by fermentation. A DNA microarray containing 4,020 genes from this organism was constructed to explore anaerobic gene expression patterns on a genomic scale. When mRNA levels of aerobic and anaerobic cultures during exponential growth were compared, several hundred genes were observed to be induced or repressed under anaerobic conditions. These genes are involved in a variety of cell functions, including carbon metabolism, electron transport, iron uptake, antibiotic production, and stress response. Among the highly induced genes are not only those responsible for nitrate respiration and fermentation but also those of unknown function. Certain groups of genes were specifically regulated during anaerobic growth on nitrite, while others were primarily affected during fermentative growth, indicating a complex regulatory circuitry of anaerobic metabolism. PMID:10913079

  3. Anaerobic treatment of pulp and paper mill effluents--status quo and new developments.

    PubMed

    Habets, Leo; Driessen, Willie

    2007-01-01

    Since the early 1980s, anaerobic treatment of industrial effluents has found widespread application in the pulp and paper industry. Over 200 installations are treating a large variety of different pulp and paper mill effluents. Amongst various anaerobic systems the UASB and IC are the most applied anaerobic reactor systems. Anaerobic treatment is well feasible for effluents originated from recycle paper mills, mechanical pulping (peroxide bleached), semi-chemical pulping and sulphite and kraft evaporator condensates. The advantages of anaerobic pre-treatment are (1) net production of renewable energy (biogas), (2) minimized bio-solids production, (3) minimal footprint and (4) reduced emission of greenhouse gases. Via in-line application of anaerobic treatment in closed circuits (paper kidney technology) further savings on cost of fresh water intake and effluent discharge levies are generated. PMID:17486855

  4. Parameter analysis of the IWA Anaerobic Digestion Model No. 1 for the anaerobic digestion of blackwater with kitchen refuse.

    PubMed

    Feng, Y; Behrendt, J; Wendland, C; Otterpohl, R

    2006-01-01

    The IWA anaerobic digestion model No.1 (ADM1) had been successfully applied to the lab-scale mesophilic blackwater anaerobic digestion (BWAD) plant for cases of only blackwater (BW) feeding and of BW plus kitchen refuse (KR) feeding. In this paper, the simulation results of BW + KR anaerobic digestion are presented and discussed, followed by the analyses and discussion of the critical and important parameters as well as the performance of ADM1 based on these results. The raw BW can contain up to 30% short chain fatty acids (SCFA) which severely impact the performance of the model. The model proved that the disintegration/hydrolysis rate of BW is around 4.5 d(-1), which is about ten times higher than that of KR (Kdis,KR = 0.5 d(-1)). ADM1 is not sensitive to the distribution ratio among carbohydrates, proteins and lipids. For BWAD the C4 metabolism can be integrated in the uptake of LCFA. The uptake delay phenomenon was observed and cannot be simulated by ADM1, but it is tolerable. No unique KI,NH3,ac is found out for all investigated ammonia concentration ranges. Meanwhile, ADM1 is not sensitive to KLa and kp1 so they can easily be set up. PMID:17037179

  5. Application of Anaerobic Digestion Model No. 1 to describe the syntrophic acetate oxidation of poultry litter in thermophilic anaerobic digestion.

    PubMed

    Rivera-Salvador, Víctor; López-Cruz, Irineo L; Espinosa-Solares, Teodoro; Aranda-Barradas, Juan S; Huber, David H; Sharma, Deepak; Toledo, J Ulises

    2014-09-01

    A molecular analysis found that poultry litter anaerobic digestion was dominated by hydrogenotrophic methanogens which suggests that bacterial acetate oxidation is the primary pathway in the thermophilic digestion of poultry litter. IWA Anaerobic Digestion Model No. 1 (ADM1) was modified to include the bacterial acetate oxidation process in the thermophilic anaerobic digestion (TAD). Two methods for ADM1 parameter estimation were applied: manual calibration with non-linear least squares (MC-NLLS) and an automatic calibration using differential evolution algorithms (DEA). In terms of kinetic parameters for acetate oxidizing bacteria, estimation by MC-NLLS and DEA were, respectively, km 1.12 and 3.25 ± 0.56 kg COD kg COD(-1)d(-1), KS 0.20 and 0.29 ± 0.018 kg COD m(-3) and Yac-st 0.14 and 0.10 ± 0.016 kg COD kg COD(-1). Experimental and predicted volatile fatty acids and biogas composition were in good agreement. Values of BIAS, MSE or INDEX demonstrate that both methods (MC-NLLS and DEA) increased ADM1 accuracy. PMID:25011081

  6. Anaerobic co-digestion of dairy manure and potato waste

    NASA Astrophysics Data System (ADS)

    Yadanaparthi, Sai Krishna Reddy

    Dairy and potato are two important agricultural commodities in Idaho. Both the dairy and potato processing industries produce a huge amount of waste which could cause environmental pollution. To minimize the impact of potential pollution associated with dairy manure (DM) and potato waste (PW), anaerobic co-digestion has been considered as one of the best treatment process. The purpose of this research is to evaluate the anaerobic co-digestion of dairy manure and potato waste in terms of process stability, biogas generation, construction and operating costs, and potential revenue. For this purpose, I conducted 1) a literature review, 2) a lab study on anaerobic co-digestion of dairy manure and potato waste at three different temperature ranges (ambient (20-25°C), mesophilic (35-37°C) and thermophilic (55-57°C) with five mixing ratios (DM:PW-100:0, 90:10, 80:20, 60:40, 40:60), and 3) a financial analysis for anaerobic digesters based on assumed different capital costs and the results from the lab co-digestion study. The literature review indicates that several types of organic waste were co-digested with DM. Dairy manure is a suitable base matter for the co-digestion process in terms of digestion process stability and methane (CH4) production (Chapter 2). The lab tests showed that co-digestion of DM with PW was better than digestion of DM alone in terms of biogas and CH4 productions (Chapter 3). The financial analysis reveals DM and PW can be used as substrate for full size anaerobic digesters to generate positive cash flow within a ten year time period. Based on this research, the following conclusions and recommendations were made: ▸ The ratio of DM:PW-80:20 is recommended at thermophilic temperatures and the ratio of DM:PW-90:10 was recommended at mesophilic temperatures for optimum biogas and CH4 productions. ▸ In cases of anaerobic digesters operated with electricity generation equipment (generators), low cost plug flow digesters (capital cost of 600/cow

  7. The Diverse Microbiology of Anaerobic Fe(II) Oxidation

    NASA Astrophysics Data System (ADS)

    Coates, J. D.; Weber, K. A.; Scherer, M.; Achenbach, L. A.

    2007-12-01

    Although anaerobic microbial oxidation of Fe(II) has been know for over a decade there is still a paucity of information available on this important metabolic process or the organisms involved. Recent studies have indicated that the metabolism is ubiquitous and a broad diversity of organisms are capable of oxidizing Fe(II) in the absence of oxygen. Our previous studies demonstrated the existence of geochemical conditions conducive to supporting the activity of nitrate-dependent Fe(II) oxidizing bacteria (NFoB) in sedimentary environments. As part of these studies we isolated and characterized several novel NFoBs. Three of these organisms, Diaphorobacter sp. strain TPSY, Ferrutens nitratireducens strain 2002 and Azospira suillum strain PS are currently undergoing whole genome shotgun sequencing in an effort to gain insight into the biochemistry and molecular biology of this geochemically important metabolism. These organisms represent diverse genera capable of anaerobically oxidizing Fe(II) using nitrate as the electron acceptor. Two of these organisms, strain 2002 and strain TPSY, are also capable of the anaerobic nitrate-dependent oxidation of U(IV) to U(VI). Diaphorobacter sp. strain TPSY was isolated from uranium and nitrate contaminated groundwater and is a member of the Comamonadaceae family in the beta subclass of the Proteobacteria, closely related to Diaphorobacter nitroreducens. It represents the first example of an anaerobic Fe(II)-oxidizer from the Comamonadaceae family and grows mixotrophically requiring an organic carbon source when growing with Fe(II) and nitrate as the electron donor and acceptor respectively. F. nitratireducens strain 2002 was isolated from aquatic sediment and is the type strain of a new genus, Ferrutens, in the beta class of the Proteobacteria. Its closest relative is Chromobacterium violaceum, a common soil bacterium. In contrast to C. violaceum, F. nitratireducens is non-fermentative and does not produce free cyanide (CN-) or

  8. Anaerobic digestion of pulp and paper mill wastewater and sludge.

    PubMed

    Meyer, Torsten; Edwards, Elizabeth A

    2014-11-15

    Pulp and paper mills generate large amounts of waste organic matter that may be converted to renewable energy in form of methane. The anaerobic treatment of mill wastewater is widely accepted however, usually only applied to few selected streams. Chemical oxygen demand (COD) removal rates in full-scale reactors range between 30 and 90%, and methane yields are 0.30-0.40 m(3) kg(-1) COD removed. Highest COD removal rates are achieved with condensate streams from chemical pulping (75-90%) and paper mill effluents (60-80%). Numerous laboratory and pilot-scale studies have shown that, contrary to common perception, most other mill effluents are also to some extent anaerobically treatable. Even for difficult-to-digest streams such as bleaching effluents COD removal rates range between 15 and 90%, depending on the extent of dilution prior to anaerobic treatment, and the applied experimental setting. Co-digestion of different streams containing diverse substrate can level out and diminish toxicity, and may lead to a more robust microbial community. Furthermore, the microbial population has the ability to become acclimated and adapted to adverse conditions. Stress situations such as toxic shock loads or temporary organic overloading may be tolerated by an adapted community, whereas they could lead to process disturbance with an un-adapted community. Therefore, anaerobic treatment of wastewater containing elevated levels of inhibitors or toxicants should be initiated by an acclimation/adaptation period that can last between a few weeks and several months. In order to gain more insight into the underlying processes of microbial acclimation/adaptation and co-digestion, future research should focus on the relationship between wastewater composition, reactor operation and microbial community dynamics. The potential for engineering and managing the microbial resource is still largely untapped. Unlike in wastewater treatment, anaerobic digestion of mill biosludge (waste activated

  9. Paper Chromatography as an Adjunct in the Identification of Anaerobic Bacteria

    PubMed Central

    Slifkin, M.; Hercher, H. J.

    1974-01-01

    Modified paper chromatography procedures for the analysis of fatty acids produced by anaerobic bacteria are described. Both ethylamine and hydroxylamine derivatives of fatty acids were prepared from inoculated anaerobic culture broth. The derivatives were spotted on chromatography paper and developed with appropriate solvents. Paper chromatography is a valuable alternative to gas liquid chromatography as an ancillary procedure in the identification of anaerobic bacteria in the clinical bacteriology laboratory. PMID:4596386

  10. Anaerobic survival of clinical isolates and laboratory strains of Neisseria gonorrhoea: use in transfer and storage.

    PubMed Central

    Short, H B; Clark, V L; Kellogg, D S; Young, F E

    1982-01-01

    Eleven laboratory strains and 67 clinical isolates of Neisseria gonorrhoeae were tested for the ability to survive during anaerobic incubation. The survival of the laboratory strains was dependent on auxotype, temperature, and cell density on agar plates. For both the laboratory strains and the clinical isolates, anaerobic survival was better at lower temperatures. We concluded that anaerobic incubation, for as long as 7 days, is useful when transporting or storing N. gonorrhoeae. Images PMID:6808019

  11. Energy positive domestic wastewater treatment: the roles of anaerobic and phototrophic technologies.

    PubMed

    Shoener, B D; Bradley, I M; Cusick, R D; Guest, J S

    2014-05-01

    The negative energy balance of wastewater treatment could be reversed if anaerobic technologies were implemented for organic carbon oxidation and phototrophic technologies were utilized for nutrient recovery. To characterize the potential for energy positive wastewater treatment by anaerobic and phototrophic biotechnologies we performed a comprehensive literature review and analysis, focusing on energy production (as kJ per capita per day and as kJ m(-3) of wastewater treated), energy consumption, and treatment efficacy. Anaerobic technologies included in this review were the anaerobic baffled reactor (ABR), anaerobic membrane bioreactor (AnMBR), anaerobic fluidized bed reactor (AFB), upflow anaerobic sludge blanket (UASB), anaerobic sequencing batch reactor (ASBR), microbial electrolysis cell (MEC), and microbial fuel cell (MFC). Phototrophic technologies included were the high rate algal pond (HRAP), photobioreactor (PBR), stirred tank reactor, waste stabilization pond (WSP), and algal turf scrubber (ATS). Average energy recovery efficiencies for anaerobic technologies ranged from 1.6% (MFC) to 47.5% (ABR). When including typical percent chemical oxygen demand (COD) removals by each technology, this range would equate to roughly 40-1200 kJ per capita per day or 110-3300 kJ m(-3) of treated wastewater. The average bioenergy feedstock production by phototrophic technologies ranged from 1200-4700 kJ per capita per day or 3400-13 000 kJ m(-3) (exceeding anaerobic technologies and, at times, the energetic content of the influent organic carbon), with usable energy production dependent upon downstream conversion to fuels. Energy consumption analysis showed that energy positive anaerobic wastewater treatment by emerging technologies would require significant reductions of parasitic losses from mechanical mixing and gas sparging. Technology targets and critical barriers for energy-producing technologies are identified, and the role of integrated anaerobic and

  12. Clinical value of anaerobic blood culture: a retrospective analysis of positive patient episodes

    PubMed Central

    James, P.; Al-Shafi, K.

    2000-01-01

    Aim—To investigate the clinical value of anaerobic blood culture. Methods—Blood culture bottles (n = 25 185) submitted for culture over a two year period were reviewed. Results—The bottles yielded 1992 positive patient episodes, a positive rate of 14.4/1000 hospital admissions. Significantly more isolations were obtained from aerobic than from anaerobic bottles. Twelve of the 38 anaerobic episodes were detected in aerobic bottles. Clinical management was influenced in one of 24 patients whose cultures yielded anaerobes from anaerobic bottles only. For a further six patients it was unlikely that the result had any effect on clinical management. Conclusions—If aerobic bottles were substituted for the anaerobic bottles, detection of positive patient episodes would increase by at least 6%. A higher yield would be achieved by using two aerobic bottles for routine culture and using anaerobic bottles only for patients where anaerobic culture may influence clinical management. Key Words: blood culture • anaerobes • BacT/Alert PMID:10823145

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

    SciTech Connect

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

    1992-05-01

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

  14. Anaerobic treatment of aircraft deicing wastes: A technology assessment. Final report

    SciTech Connect

    1998-09-01

    The work contained in the study documents the fact that deicing wastes containing ethylene glycol (EG) and propylene glycol (PG) may be effectively treated using an anaerobic biological process. In the report, the treatment of aircraft deicing wastes under anaerobic methanogenic conditions is examined in detail. The major project tasks were: airport sampling to define the characteristics of waste from deicing operations; testing of EG and PG degradation using laboratory-scale reactors and then by means of serum bottle tests; operation of an anaerobic fluidized bed reactor (AFBR); and analysis of the energy aspects of anaerobic processes with cost comparisons to traditional aerobic processes.

  15. Removal of Pesticides and Inorganic Contaminants in Anaerobic and Aerobic Biological Contactors

    EPA Science Inventory

    This presentation contains data on the removal of pesticides (acetochlor, clethodim, dicrotophos), ammonia, nitrate, bromate and perchlorate through aerobic and anaerobic biological treatment processes.

  16. 40 CFR Table II-2 to Subpart II - Collection Efficiencies of Anaerobic Processes

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Wastewater Treatment Pt. 98... process type Cover type Methane collection efficiency Covered anaerobic lagoon (biogas capture) Bank...

  17. 40 CFR Table II-2 to Subpart II - Collection Efficiencies of Anaerobic Processes

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Wastewater Treatment Pt. 98... process type Cover type Methane collection efficiency Covered anaerobic lagoon (biogas capture) Bank...

  18. What are the differences between aerobic and anaerobic toxic effects of sulfonamides on Escherichia coli?

    PubMed

    Qin, Mengnan; Lin, Zhifen; Wang, Dali; Long, Xi; Zheng, Min; Qiu, Yanling

    2016-01-01

    Bacteria in the environment face the threat of antibiotics. However, most studies investigating the toxicity and toxicity mechanisms of antibiotics have been conducted on microorganisms in aerobic conditions, while studies examining the anaerobic toxicity and toxicity mechanisms of antibiotics are still limited. In this study, we determined the aerobic and anaerobic toxicities of sulfonamides (SAs) on Escherichia coli. Next, a comparison of the aerobic and anaerobic toxicities indicated that the SAs could be divided into three groups: Group I: log(1/EC50-anaerobic)>log(1/EC50-aerobic) (EC50-anaerobic/EC50-aerobic, the median effective concentration under anaerobic/aerobic conditions), Group II: log(1/EC50-anaerobic)≈log(1/EC50-aerobic), and Group III: log(1/EC50-anaerobic)anaerobic toxicities will benefit environmental science, and the results of this study will serve as a reference for the risk assessment of chemicals in the environment. PMID:26748048

  19. Anaerobic digestion of dairy cattle manure autoheated by aerobic pretreatment

    SciTech Connect

    Achkari-Begdouri, A.

    1989-01-01

    A novel way to heat anaerobic digesters was investigated. Dairy cattle manure was autoheated by an aerobic pretreatment process and then fed to the anaerobic digester. Important physical properties of the dairy cattle manure were determined. These included bulk density, specific heat, thermal conductivity and the rheological properties; consistency coefficient, behavior index and apparent viscosity. These parameters were used to calculate the overall heat transfer coefficients, and to estimate the heat losses from the aerobic reactor to the outside environment. The total energy balance of the aerobic treatment system was then established. An optimization study of the main parameters influencing the autoheating process showed that the total solids, the air flow rate and the stirring speed for operation of the aerobic pretreatment should be approximately 7%, 70 L/H and 1,400 rpm respectively. Temperatures as high as 65C were reached in 40 hours of aerobic treatment. At the above recommended levels of total solids, the air flow rate and the stirring speed, there was little difference in the energy requirements for heating the influent by aeration and heating the influent by a conventional heating system. In addition to the temperature increase, the aerobic pretreatment assisted in balancing the anaerobic digestion process and increased the methanogenesis of the dairy cattle manure. Despite the 8% decomposition of organic matter that occurred during the aerobic pretreatment process, methane production of the digester started with the aerobically heated manure was significantly higher (at least 20% higher) than of the digester started with conventionally heated manure. The aerobic system successfully autoheated the dairy cattle manure with an energy cost equal to that of conventionally heated influent.

  20. Anaerobic/aerobic treatment of selected azo dyes in wastewater

    SciTech Connect

    Seshadri, S.; Bishop, P.L. . Dept. of Civil and Environmental Engineering); Agha, A.M. . Faculty of Civil Engineering)

    1994-01-01

    Azo dyes represent the largest class of dyes in use today. Current environmental concern with these dyes revolves around the potential carcinogenic health risk presented by these dyes or their intermediate biodegradation products when exposed to microflora in the human digestive tract. These dyes may build up in the environment, since many wastewater treatment plants allow these dyes to pass through the system virtually untreated. The initial step in the degradation of these dyes is the cleavage of the Azo bond. This cleavage is often impossible under aerobic conditions, but has been readily demonstrated under anaerobic conditions. The focus of the study was to determine the feasibility of using an anaerobic fluidized-bed reactor to accomplish this cleavage. The effects of typical process variables such as hydraulic retention time (HRT), influent dye concentration levels, and degree of bed fluidization on removal efficiencies were also studied. The four dyes selected for this study were Acid-Orange 7, Acid-Orange 8, Acid-Orange 10, and Acid-Red 14. The effectiveness of using a bench-scale-activated sludge reactor as a sequenced second stage was also examined. Results indicate that nearly complete cleavage of the Azo bond is easily accomplished for each of the four dyes under hydraulic retention times of either 12 or 24 h. Initial results indicate, though, that aromatic amine by-products remain. The sequenced second stage was able to remove the remaining Chemical Oxygen Demand (COD) load to acceptable levels. Work is presently underway to determine the face of the anaerobic by-products in the aerobic second stage.

  1. Methanogenic community shift in anaerobic batch digesters treating swine wastewater.

    PubMed

    Kim, Woong; Lee, Seungyong; Shin, Seung Gu; Lee, Changsoo; Hwang, Kwanghyun; Hwang, Seokhwan

    2010-09-01

    Qualitative and quantitative molecular analysis techniques were used to determine associations between differences in methanogenic microbial communities and the efficiency of batch anaerobic digesters. Two bioreactors were initially seeded with anaerobic sludge originating from a local municipal wastewater treatment plant and then supplemented with swine wastewater. Differences were observed in the total amount of methane produced in the two bioreactors (7.9L/L, and 4.5L/L, respectively). To explain these differences, efforts were taken to characterize the microbial populations present using a PCR-based DGGE analysis with methanogenic primer and probe sets. The groups Methanomicrobiales (MMB), Methanobacteriales (MBT), and Methanosarcinales (MSL) were detected, but Methanococcales (MCC) was not detected. Following this qualitative assay, real-time PCR was used to investigate quantitative differences in the populations of these methanogenic orders. MMB was found to be the dominant order present and its abundance patterns were different in the two digesters. The population profiles of the other methanogenic groups also differed. Through redundancy analysis, correlations between the concentrations of the different microbes and chemical properties such as volatile fatty acids were calculated. Correlations between MBT and MSL populations and chemical properties were found to be consistent in both digesters, however, differences were observed in the correlations between MMB and propionate. These results suggest that interactions between populations of MMB and other methanogens affected the final methane yield, despite MMB remaining the dominant group overall. The exact details of why changes in the MMB community caused different profiles of methane production could not be ascertained. However, this research provides evidence that microbial behavior is important for regulating the performance of anaerobic processes. PMID:20692007

  2. Evidence for Anaerobic Dechlorination of Dechlorane Plus in Sewage Sludge.

    PubMed

    Sverko, Ed; McCarry, Brian; McCrindle, Robert; Brazeau, Allison; Pena-Abaurrea, Miren; Reiner, Eric; Anne Smyth, Shirley; Gill, Biban; Tomy, Gregg T

    2015-12-01

    The environmental occurrence of dechlorination moieties from the high production volume flame retardant, Dechlorane Plus (DP), has largely been documented; however, the sources have yet to be well understood. In addition, few laboratory-based studies exist which identify the cause for the occurrence of these chemicals in the environment or humans. Anaerobic dechlorination of the two DP isomers was investigated using a laboratory-simulated wastewater treatment plant (WWTP) environment where anaerobic digestion is used as part of the treatment regime. Known amounts of each isomer were added separately to sewage sludge which provided the electron-donating substrate and at prescribed time points in the incubation, a portion of the media was removed and analyzed for DP and any dechlorination metabolites. After 7 days, monohydrodechlorinated products were observed for both the syn- and anti-DP which were continued throughout the duration of our study (49 days) in an increasing manner giving a calculated formation rate of 0.48 ± 0.09 and 0.79 ± 0.12 pmols/day for syn- and anti-DP, respectively. Furthermore, we observed a second monohydrodechlorinated product only in the anti-DP isomer incubation medium. This strongly suggests that anti-DP is more susceptible to anaerobic degradation than the syn isomer. We also provide compelling evidence to the location of chlorine loss in the dechlorination DP analogues. Finally, the dechlorination DP moieties formed in our study matched the retention times and identification of those observed in surficial sediment located downstream of the WWTP. PMID:26572321

  3. Anaerobic co-digestion of sewage sludge and food waste.

    PubMed

    Prabhu, Meghanath S; Mutnuri, Srikanth

    2016-04-01

    Anaerobic co-digestion of organic matter improves digester operating characteristics and its performance. In the present work, food waste was collected from the institute cafeteria. Two types of sludge (before centrifuge and after centrifuge) were collected from the fluidised bed reactor of the institute treating sewage wastewater. Food waste and sludge were studied for their physico-chemical characteristics, such as pH, chemical oxygen demand, total solids, volatile solids, ammoniacal nitrogen, and total nitrogen. A biomethane potential assay was carried out to find out the optimum mixing ratio of food waste and sludge for anaerobic co-digestion. Results indicated that food waste mixed with sludge in the ratio of 1:2 produced the maximum biogas of 823 ml gVS(-1)(21 days) with an average methane content of 60%. Batch studies were conducted in 5 L lab-glass reactors at a mesophilic temperature. The effect of different substrate loading rates on biogas production was investigated. The mixing ratio of food waste and sludge was 1:2. A loading rate of 1 gVS L d(-1)gave the maximum biogas production of 742 ml g(-1)VS L d(-1)with a methane content of 50%, followed by 2 gVS L d(-1)with biogas of 539 ml g(-1)VS L d(-1) Microbial diversity of the reactor during fed batch studies was investigated by terminal restriction fragment length polymorphism. A pilot-scale co-digestion of food waste and sludge (before centrifuge) indicated the process stability of anaerobic digestion. PMID:26879909

  4. Characterization of anaerobic heterotrophic bacteria isolated from freshwater lake sediments.

    PubMed

    Molongoski, J J; Klug, M J

    1976-01-01

    Strict anaerobic culture techniques were used to quantitatively and qualitatively evaluate the anaerobic heterotrophic bacteria present at the sediment-water interface of hyperutrophic Wintergreen Lake (Augusta, Mich.). Anaerobic plate counts remained constant from March through December, 1973, ranging from 2.4 X 10(6) to 5.7 X 10(6) organisms/g (dry weight) of sediment. The isolatable bacteria represented a small percentage of the total microbial community, which was shown by direct microscopic counts to be 2.0 X 10'' organisms/g (dry weight) of sediment during June and July. Bacteria of the genus Clostridium dominated the isolates obtained, accounting for 71.8% of the 960 isolates examined. A single species, Clostridium bifermentens, comprised 47.7% of the total. Additional bacterial groups and the percentage in which they were isolated included: Streptococcus sp. (10.8%), unidentified curved rods (9.5%y, gram-positive nonsporing rods (5.6%), and motile gram-negative rods (1.9%). Temperature growth studies demonstrated the ability of all the isolates to grow at in situ sediment temperatures. Gas-liqid radiochromatography was used to determine the soluble metabolic end products from [U-14C]glucose and a U-14C-labeled amino acid mixture by representative sedimentary clostridial isolates and by natural sediment microbial communities. At in situ temperatures the natural sediment microflora produced soluble fermentative end products characteristic of those elaborated by the clostridial isolates tested. These results are considered strong presumptive evidence that clostridia are actively metabolizing in the sediments of Wintergreen Lake. PMID:942211

  5. Anaerobic Biodegradation of Ethylene Glycol within Hydraulic Fracturing Fluid

    NASA Astrophysics Data System (ADS)

    Heyob, K. M.; Mouser, P. J.

    2014-12-01

    Ethylene glycol (EG) is a commonly used organic additive in hydraulic fracturing fluids used for shale gas recovery. Under aerobic conditions, this compound readily biodegrades to acetate and CO2 or is oxidized through the glycerate pathway. In the absence of oxygen, organisms within genera Desulfovibrio, Acetobacterium, and others can transform EG to acetaldehyde, a flammable and suspected carcinogenic compound. Acetaldehyde can then be enzymatically degraded to ethanol or acetate and CO2. However, little is known on how EG degrades in the presence of other organic additives, particularly under anaerobic conditions representative of deep groundwater aquifers. To better understand the fate and attenuation of glycols within hydraulic fracturing fluids we are assessing their biodegradation potential and pathways in batch anaerobic microcosm treatments. Crushed Berea sandstone was inoculated with groundwater and incubated with either EG or a synthetic fracturing fluid (SFF) containing EG formulations. We tracked changes in dissolved organic carbon (DOC), EG, and its transformation products over several months. Approximately 41% of bulk DOC in SFF is degraded within 21 days, with 58% DOC still remaining after 63 days. By comparison, this same SFF degrades by 70% within 25 days when inoculated with sediment-groundwater microbial communities, suggesting that bulk DOC degradation occurs at a slower rate and to a lesser extent with bedrock. Aerobic biodegradation of EG occurs rapidly (3-7 days); however anaerobic degradation of EG is much slower, requiring several weeks for substantial DOC loss to be observed. Ongoing experiments are tracking the degradation pathways of EG alone and in the presence of SFF, with preliminary data showing incomplete glycol transformation within the complex hydraulic fracturing fluid mixture. This research will help to elucidate rates, processes, and pathways for EG biodegradation and identify key microbial taxa involved in its degradation.

  6. Energetics and kinetics of anaerobic aromatic and fatty acid degradation

    SciTech Connect

    McInerney, M.J.

    1992-11-16

    The kinetics of benzoate degradation by the anaerobic syntrophic bacterium, Syntrophus buswellii, was studied in coculture with Desulfovibrio strain G11. The threshold value for benzoate degradation was dependent on the acetate concentration with benzoate threshold values ranging from 2.4 [mu]M at 20 mM acetate to 30.0 [mu]M at 65 mM acetate. Increasing acetate concentrations also inhibited the rate of benzoate degradation with a apparent K[sub i] for acetate inhibition of 7.0 mM. Lower threshold values were obtained when nitrate rather than sulfate was the terminal electron acceptor. These data are consistent with a thermodynamic explanation for the threshold, and suggest that there is a minimum Gibbs free energy value required for the degradation of benzoate. An acetoacetyl-CoA thiolase has been isolated from Syntrophomonas wolfei; it is apparently a key enzyme controlling the synthesis of poly-B-hydroxyalkanoate from acetyl-CoA in this organism. Kinetic characterization of the acetoacetyl-CoA thiolase from S. wolfei showed that it is similar in its structural, kinetic, and apparent regulatory properties to other biosynthetic acetoacetyl-CoA thiolases from phylogenetically distinct bacteria that synthesize PHA. Intracellular concentrations of CoA and acetyl-CoA are believed to be critical factors regulating the activity of the acetoacetyl-CoA thiolase in S. wolfei. We have also isolated and characterized several new halophilic anaerobic fermentative anaerobes. Phylogenetic analysis indicates that one of these bacteria is a new species in the genus, Haloanaerobium. Two other species appear to be members of the genus, Halobacteroides. Several halophilic acetoclastic methanogenic bacteria have also been isolated and their physiological properties are currently under investigation. We have also isolated an acetate-using dissimilatory iron-reducing bacterium.

  7. Assessing in situ rates of anaerobic hydrocarbon bioremediation

    PubMed Central

    Gieg, Lisa M.; Alumbaugh, Robert E.; Field, Jennifer; Jones, Jesse; Istok, Jonathon D.; Suflita, Joseph M.

    2009-01-01

    Summary Identifying metabolites associated with anaerobic hydrocarbon biodegradation is a reliable way to garner evidence for the intrinsic bioremediation of problem contaminants. While such metabolites have been detected at numerous sites, the in situ rates of anaerobic hydrocarbon decay remain largely unknown. Yet, realistic rate information is critical for predicting how long individual contaminants will persist and remain environmental threats. Here, single‐well push–pull tests were conducted at two fuel‐contaminated aquifers to determine the in situ biotransformation rates of a suite of hydrocarbons added as deuterated surrogates, including toluene‐d8, o‐xylene‐d10, m‐xylene‐d10, ethylbenzene‐d5 (or ‐d10), 1, 2, 4‐trimethylbenzene‐d12, 1, 3, 5‐trimethylbenzene‐d12, methylcyclohexane‐d14 and n‐hexane‐d14. The formation of deuterated fumarate addition and downstream metabolites was quantified and found to be somewhat variable among wells in each aquifer, but generally within an order of magnitude. Deuterated metabolites formed in one aquifer at rates that ranged from 3 to 50 µg l−1 day−1, while the comparable rates at another aquifer were slower and ranged from 0.03 to 15 µg l−1 day−1. An important observation was that the deuterated hydrocarbon surrogates were metabolized in situ within hours or days at both sites, in contrast to many laboratory findings suggesting that long lag periods of weeks to months before the onset of anaerobic biodegradation are typical. It seems clear that highly reduced conditions are not detrimental to the intrinsic bioremediation of fuel‐contaminated aquifers. PMID:21261916

  8. Anaerobic Bacteremia: Impact of Inappropriate Therapy on Mortality

    PubMed Central

    Lee, Yangsoon; Park, Yongjung; Kim, Myungsook; Choi, Jun Yong; Yong, Dongeun; Jeong, Seok Hoon

    2016-01-01

    Background Investigation on incidence and mortality of anaerobic bacteremia (AB) is clinically relevant in spite of its infrequent occurrence and not often explored, which report varies according to period and institutions. Therefore, it is necessary to analyze the incidence and risk factors related to mortality and assess clinical outcomes of AB in current aspect. Materials and Methods Characteristics of AB patients and anaerobic bacteria from blood culture at a university hospital in 2012 were reviewed retrospectively. The correlation between risk factors and 28-day patient mortality was analyzed. Results A total of 70 non-duplicated anaerobic bacteria were isolated from blood of 70 bacteremia patients in 2012. The history of cardiovascular disease as host's risk factor was statistically significant (P = 0.0344) in univariate and multivariate analysis. Although the inappropriate therapy was not statistically significant in univariate and multivariate analysis, the survival rate of bacteremia was significantly worse in patients who had inappropriate therapy compared with those underwent appropriate therapy (hazard ratio, 5.4; 95% confidence interval, 1.7–6.9; P = 0.004). The most frequently isolated organism was Bacteroides fragilis (32 isolates, 46%), followed by Bacteroides thetaiotaomicron (10, 14%), and non-perfringens Clostridium (7, 10%). Conclusion The incidence of AB in 2012 was 2.3% (number of AB patients per 100 positive blood culture patients) and the mortality rate in patients with clinically significant AB was 21.4%. In addition, AB was frequently noted in patients having malignancy and the survival rate of AB was significantly worse in patients who received inappropriate therapy compared with those underwent appropriate therapy. PMID:27433379

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

    PubMed

    Korenblum, Elisa; Jiménez, Diego Javier; van Elsas, Jan Dirk

    2016-03-01

    Anaerobic bacteria degrade lignocellulose in various anoxic and organically rich environments, often in a syntrophic process. Anaerobic enrichments of bacterial communities on a recalcitrant lignocellulose source were studied combining polymerase chain reaction-denaturing gradient gel electrophoresis, amplicon sequencing of the 16S rRNA gene and culturing. Three consortia were constructed using the microbiota of lake sediment as the starting inoculum and untreated switchgrass (Panicum virgatum) (acid or heat) or treated (with either acid or heat) as the sole source of carbonaceous compounds. Additionally, nitrate was used in order to limit sulfate reduction and methanogenesis. Bacterial growth took place, as evidenced from 3 to 4 log unit increases in the 16S rRNA gene copy numbers as well as direct cell counts through three transfers on cleaned and reused substrate placed in fresh mineral medium. After 2 days, Aeromonas bestiarum-like organisms dominated the enrichments, irrespective of the substrate type. One month later, each substrate revealed major enrichments of organisms affiliated with different species of Clostridium. Moreover, only the heat-treated substrate selected Dysgonomonas capnocytophagoides-affiliated bacteria (Bacteroidetes). Towards the end of the experiment, members of the Proteobacteria (Aeromonas, Rhizobium and/or Serratia) became dominant in all three types of substrates. A total of 160 strains was isolated from the enrichments. Most of the strains tested (78%) were able to grow anaerobically on carboxymethyl cellulose and xylan. The final consortia yield attractive biological tools for the depolymerization of recalcitrant lignocellulosic materials and are proposed for the production of precursors of biofuels. PMID:26875750

  10. Lack of Activity of Sulfamethoxazole and Trimethoprim Against Anaerobic Bacteria

    PubMed Central

    Rosenblatt, J. E.; Stewart, P. R.

    1974-01-01

    The activity of sulfamethoxazole (SMX), trimethoprim (TMP), and the combination of the two was determined against a variety of anaerobic bacteria. Brucella agar was somewhat inhibitory for SMX and TMP but activity was good and equivalent in Diagnostic Sensitivity Test Agar (Oxoid) and Mueller-Hinton agar and the latter was selected for use in these studies. Agar dilution susceptibility tests showed that 95 of 98 anaerobic isolates were resistant to ≥100 μg of SMX per ml and 85 were resistant to ≥6.25 μg of TMP per ml. “Checkerboard” agar dilution studies of combined activity showed that 66 of 72 isolates were resistant to ≥ (100 μg of SMX per ml + 6.25 μg of TMP per ml) and only six isolates were susceptible to the synergistic activity of the combination. The majority of 32 isolates tested by the disk diffusion method were also resistant to SMX and TMP individually and to the combination 25-μg disk. Correlation between agar dilution minimal inhibitory concentration and disk zone size results was in general good for individual agents. Four Bacteroides fragilis isolates were inhibited by the combination 25-μg disk but were resistant to SMX + TMP by agar dilution “checkerboard.” This discrepancy may have been due to different incubation periods since disk results also showed resistance when read after 48 h (as is done with agar dilution) rather than the standard 24 h for disk tests. These studies suggest that SMX and TMP, either individually or in combination, are not active against the great majority of anaerobic bacteria. PMID:15828176

  11. Anaerobic digestion of municipal solid waste: Technical developments

    SciTech Connect

    Rivard, C.J.

    1996-01-01

    The anaerobic biogasification of organic wastes generates two useful products: a medium-Btu fuel gas and a compost-quality organic residue. Although commercial-scale digestion systems are used to treat municipal sewage wastes, the disposal of solid organic wastes, including municipal solid wastes (MSW), requires a more cost-efficient process. Modern biogasification systems employ high-rate, high-solids fermentation methods to improve process efficiency and reduce capital costs. The design criteria and development stages are discussed. These systems are also compared with conventional low-solids fermentation technology.

  12. Deploying anaerobic digesters: Current status and future possibilities

    SciTech Connect

    Lusk, P.; Wheeler, P.; Rivard, C.

    1996-01-01

    Unmanaged pollutants from putrescible farm, industrial, and municipal wastes degrade in the environment, and methane emitted from their decomposition may contribute to global climate change. Under modern environmental regulations, these wastes are becoming difficult to dispose of using traditional means. One waste management system, anaerobic digestion or AD, not only provides pollution prevention but can also convert a disposal problem into a new profit center. This report is drawn from a special session of the Second Biomass Conference of the Americas. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  13. Clostridiumm ljungdahlii, an anaerobic ethanol and acetate producing microorganism

    DOEpatents

    Gaddy, J.L.; Clausen, E.C.

    1992-12-22

    A newly discovered microorganism was isolated in a biologically pure culture and designated Clostridium ljungdahlii, having the identifying characteristics of ATCC No. 49587. Cultured in an aqueous nutrient medium under anaerobic conditions, this microorganism is capable of producing ethanol and acetate from CO and H[sub 2]O and/or CO[sub 2] and H[sub 2] in synthesis gas. Under optimal growth conditions, the microorganism produces acetate in preference to ethanol. Conversely, under non-growth conditions, ethanol production is favored over acetate. 3 figs.

  14. Clostridiumm ljungdahlii, an anaerobic ethanol and acetate producing microorganism

    DOEpatents

    Gaddy, James L.; Clausen, Edgar C.

    1992-01-01

    A newly discovered microorganism was isolated in a biologically pure culture and designated Clostridium ljungdahlii, having the identifying characteristics of ATCC No. 49587. Cultured in an aqueous nutrient medium under anaerobic conditions, this microorganism is capable of producing ethanol and acetate from CO and H.sub.2 O and/or CO.sub.2 and H.sub.2 in synthesis gas. Under optimal growth conditions, the microorganism produces acetate in preference to ethanol. Conversely, under non-growth conditions, ethanol production is favored over acetate.

  15. Anaerobic Nitrate-Dependent Metal Bio-Oxidation

    NASA Astrophysics Data System (ADS)

    Weber, K.; Knox, T.; Achenbach, L. A.; Coates, J. D.

    2007-12-01

    Direct biological oxidation of reduced metals (Fe(II) and U(IV)) coupled to nitrate reduction at circumneutral pH under anaerobic conditions has been recognized in several environments as well as pure culture. Several phylogentically diverse mesophilic bacteria have been described as capable of anaerobic, nitrate-dependent Fe(II) oxidation (NFOx). Our recent identification of a freshwater mesophilic, lithoautotroph, Ferrutens nitratireducens strain 2002, capable of growth through NFOx presents an opportunity to further study metal bio- oxidation. Continuing physiological studies revealed that in addition to Fe(II) oxidation, strain 2002 is capable of oxidizing U(IV) (4 μM) in washed cell suspensions with nitrate serving as the electron acceptor. Pasteurized cultures exhibited abiotic oxidation of 2 μM U(IV). Under growth conditions, strain 2002 catalyzed the oxidation of 12 μM U(IV) within a two week period. Cultures amended with sodium azide, an electron transport inhibitor, demonstrated limited oxidation (7 μM) similar to pasteurized cultures, supporting the direct role of electron transport in U(IV) bio-oxidation. The oxidation of U(IV) coupled denitrification at circumneutral pH would yield enough energy to support anaerobic microbial growth (ΔG°'= -460.36 kJ/mole). It is currently unknown whether or not strain 2002 can couple this metabolism to growth. The growth of F. nitratireducens strain 2002 utilizing Fe(II) as the sole electron donor was previously demonstrated. The amount of U(IV) (~12 μM) that strain 2002 oxidized under similar autotrophic growth conditions yields 0.0019 kJ, enough energy for the generation of ATP (5.3 x 10-20 kJ ATP-1), but not enough energy for cell replication as calculated for nitrate-dependent Fe(II) oxidizing conditions (0.096 kJ) assuming a similar metabolism. In addition to F. nitratireducens strain 2002, a nitrate-dependent Fe(II) oxidizing bacterium isolated from U contaminated groundwater, Diaphorobacter sp. strain

  16. Anaerobic utilization of phosphite and hypophosphite by Bacillus sp.

    NASA Technical Reports Server (NTRS)

    Foster, T. L.; Winans, L., Jr.; Helms, S. J. S.

    1978-01-01

    A Bacillus species capable of using phosphite and hypophosphite under anaerobic conditions was isolated from Cape Canaveral soil samples and grown on a glucose-mineral salts medium with phosphate omitted. The optimum hypophosphite concentration was 60 microg/ml, while the optimum phosphite concentration was greater than 1000 microg/ml. P-32-labeled hypophosphite was incorporated into the cell as organic phosphate, and little or no phosphate appeared in the medium when either hypophosphite or phosphite was the phosphorus source. When phosphate was present in the medium, phosphite was not metabolized. When both phosphite and hypophosphite were present, phosphite was used first and then hypophosphite.

  17. Anaerobic bioassay of methane potential of microalgal biomass

    NASA Astrophysics Data System (ADS)

    Yen, Hong-Wei

    This study was undertaken to investigate the feasibility of using anaerobic digestion as a technique to recover solar energy embodied in excess algal biomass production harvested from Clemson University's high rate algal based Partitioned Aquaculture System (PAS) as an energy source to support PAS operations. In this study, four different organic substrates were loaded to anaerobic digesters in eight experimental trials, to ascertain the optimal combination of operational variables and effect of algal, or modified algal substrate upon methane production rate. The four substrates used in this study were: (1) a synthetic feedstock consisting of molasses and dog food, (2) a commercially obtained, readily degradable algal biomass (Spirulina ) in dry form, (3) PAS harvested and dewatered algal sludge, and (4) algal biomass blended with shredded waste paper or molasses as a carbon supplement for the adjustment of algal C/N ratio. Eight experimental trials using combinations of the four substrates were conducted in 15 liter digesters to investigate the effects of controlled digester parameters upon digester performance. Digesters operating at 20 days HRT, mesophilic digestion (35°C), and twice per day mixing at maximal loading rates produced maximal methane gas using PAS algal sludge. However, under these conditions overall methane production was less than 1000 ml CH4/l day. This low level of energy recovery from the fermentation of algal biomass (alone) is not energetically or economically favorable. Co-digestion of algal sludge and waste paper was investigated as a way to increase methane production. The data obtained from these trials suggest an optimum C/N ratio for co-digestion of algal sludge and waste paper in the range of 20--25/l. A balanced C/N ratio along with the stimulated increase in cellulase activity is suggested as likely reasons for increased methane production seen in co-digestion of algal sludge and waste paper. Yeast extract addition to anaerobic

  18. Anaerobic ammonium oxidation for treatment of ammonium-rich wastewaters*

    PubMed Central

    Zhang, Lei; Zheng, Ping; Tang, Chong-jian; Jin, Ren-cun

    2008-01-01

    The concept of anaerobic ammonium oxidation (ANAMMOX) is presently of great interest. The functional bacteria belonging to the Planctomycete phylum and their metabolism are investigated by microbiologists. Meanwhile, the ANAMMOX is equally valuable in treatment of ammonium-rich wastewaters. Related processes including partial nitritation-ANAMMOX and completely autotrophic nitrogen removal over nitrite (CANON) have been developed, and lab-scale experiments proved that both processes were quite feasible in engineering with appropriate control. Successful full-scale practice in the Netherlands will accelerate application of the process in future. This review introduces the microbiology and more focuses on application of the ANAMMOX process. PMID:18500782

  19. Pathways and Bioenergetics of Anaerobic Carbon Monoxide Fermentation

    PubMed Central

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

    2015-01-01

    Carbon monoxide can act as a substrate for different modes of fermentative anaerobic metabolism. The trait of utilizing CO is spread among a diverse group of microorganisms, including members of bacteria as well as archaea. Over the last decade this metabolism has gained interest due to the potential of converting CO-rich gas, such as synthesis gas, into bio-based products. Three main types of fermentative CO metabolism can be distinguished: hydrogenogenesis, methanogenesis, and acetogenesis, generating hydrogen, methane and acetate, respectively. Here, we review the current knowledge on these three variants of microbial CO metabolism with an emphasis on the potential enzymatic routes and bio-energetics involved. PMID:26635746

  20. Multidrug Efflux Systems in Microaerobic and Anaerobic Bacteria

    PubMed Central

    Xu, Zeling; Yan, Aixin

    2015-01-01

    Active drug efflux constitutes an important mechanism of antibiotic and multidrug resistance in bacteria. Understanding the distribution, expression, and physiological functions of multidrug efflux pumps, especially under physiologically and clinically relevant conditions of the pathogens, is the key to combat drug resistance. In animal hosts, most wounded, infected and inflamed tissues display low oxygen tensions. In this article, we summarize research development on multidrug efflux pumps in the medicinally relevant microaerobic and anaerobic pathogens and their implications in the effort to combat drug-resistant infections. PMID:27025630

  1. An anaerobic reaction between lipoxygenase, linoleic acid and its hydroperoxides

    PubMed Central

    Garssen, G. J.; Vliegenthart, J. F. G.; Boldingh, J.

    1971-01-01

    In an anaerobic system soya-bean lipoxygenase together with linoleic acid induces a structural rearrangement of 13-hydroperoxyoctadeca-cis-9-trans-11-dienoic acid leading to the formation of 13-oxotrideca-cis(trans)-9-trans-11-dienoic acid and n-pentane as well as 13-oxo-octadeca-9,11-dienoic acid. It is proposed that the 13-peroxyoctadeca-cis-9-trans-11-dienoic acid radical formed through hydrogen radical abstraction by the linoleic acid radical is the key intermediate for these reactions. PMID:5165730

  2. Rapid methods for biochemical testing of anaerobic bacteria.

    PubMed

    Schreckenberger, P C; Blazevic, D J

    1974-11-01

    Rapid biochemical tests for nitrate, indole, gelatin, starch, esculin, and o-nitrophenyl-beta-D-galactopyranoside were performed on 112 strains of anaerobic bacteria. All tests were incubated under aerobic conditions, and results were recorded within 4 h. The tests for nitrate, indole, and starch showed a 95% or greater correlation when compared to the standard biochemical tests. Tests for esculin and gelatin showed an agreement of 86 and 77%, respectively. PathoTec test strips for nitrate, indole, esculin, o-nitrophenyl-beta-D-galactopyranoside, Voges-Proskauer, and urease were also tested and showed encouraging results. PMID:4613268

  3. Anaerobic degradation of aircraft deicing fluid (ADF) in upflow anaerobic sludge blanket (UASB) reactors and the fate of ADF additives

    NASA Astrophysics Data System (ADS)

    Pham, Thi Tham

    2002-11-01

    A central composite design was employed to methodically investigate anaerobic treatment of aircraft deicing fluid (ADF) in bench-scale Upflow Anaerobic Sludge Blanket (UASB) reactors. A total of 23 runs at 17 different operating conditions were conducted in continuous mode. The development of four empirical models describing process responses (i.e., chemical oxygen demand (COD) removal efficiency, biomass specific acetoclastic activity, methane production rate, and methane production potential) as functions of ADF concentration, hydraulic retention time (HRT), and biomass concentration is presented. Model verification indicated that predicted responses (COD removal efficiencies, biomass specific acetoclastic activity, and methane production rates and potential) were in good agreement with experimental results. Biomass specific acetoclastic activity was improved by almost two-fold during ADF treatment in UASB reactors. For the design window, COD removal efficiencies were higher than 90%. Predicted methane production potentials were close to theoretical values, and methane production rates increased as the organic loading rate (OLR) was increased. ADF toxicity effects were evident for 1.6% ADF at medium specific organic loadings (SOLR above 0.5 g COD/g VSS/d). In contrast, good reactor stability and excellent removal efficiencies were achieved at 1.2% ADF for reactor loadings approaching that of highly loaded systems (0.73 g COD/g VSS/d). Acclimation to ADF resulted in an initial reduction in the biomass settling velocity. The fate of ADF additives was also investigated. There was minimal sorption of benzotriazole (BT), 5-methyl-1 H-benzotriazole (MeBT), and 5,6-dimethyl-1 H-benzotriazole (DiMeBT) to anaerobic granules. A higher sorption capacity was measured for NP. Active transport may be one of the mechanisms for NP sorption. Ethylene glycol degradation experiments indicated that BT, MeBT, DiMeBT, and the nonionic surfactant Tergitol NP-4 had no significant

  4. ANAEROBIC/AEROBIC BIODEGRADATION OF PENTACHLOROPHENOL USING GAC FLUIDIXED BED REACTORS: OPTIMIZATION OF THE EMPTY BED CONTACT TIME

    EPA Science Inventory

    An integrated reactor system has been developed to remediate pentachlorophenol (PCP) containing wastes using sequential anaerobic and aerobic biodegradation. Anaerobically, PCP was degraded to approximately equimolar concentrations (>99%) of chlorophenol (CP) in a granular activa...

  5. The Impact of Temperature on Anaerobic Biological Perchlorate Removal and Aerobic Polishing of the Effluent - paper

    EPA Science Inventory

    This abstract describes a pilot-scale evaluation of anaerobic biological perchlorate (C1O4) removal followed by aerobic effluent polishing. The anaerobic biological contactor operated for 3.5 years. During that period, two effluent polishing evaluations, lasting 311 an...

  6. [[sup 3]H] Thymidine incorporation to estimate growth rates of anaerobic bacterial strains

    SciTech Connect

    Winding, A. )

    1992-08-01

    The incorporation of [[sup 3]H] thymidine by axenic cultures of anaerobic bacteria was investigated as a means to measure growth. The three fermentative strains and one of the methanogenic strains tested incorporated [[sup 3]H] thymidine during growth. It is concluded that the [[sup 3]H] thymidine incorporation method underestimates bacterial growth in anaerobic environments.

  7. The Impact of Temperature on Anaerobic Biological Perchlorate Removal and Aerobic Polishing of the Effluent

    EPA Science Inventory

    This abstract describes a pilot-scale evaluation of anaerobic biological perchlorate (C1O4) removal followed by aerobic effluent polishing. The anaerobic biological contactor operated for 3.5 years. During that period, two effluent polishing evaluations, lasting 311 an...

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

    PubMed Central

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

    2015-01-01

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

  9. Exploring warm-season cover crops as carbon sources for anaerobic soil disinfestation (ASD)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic soil disinfestation (ASD) has been shown to be an effective strategy for controlling soilborne plant pathogens and plant parasitic nematodes in vegetable production systems. Soil treatment by ASD relies on the supply of labile carbon (C) to stimulate microbially-driven anaerobic soil condi...

  10. Inhibition of biogas production by alkyl benzene sulfonates (LAS) in a screening test for anaerobic biodegradability.

    PubMed

    Garcia, M Teresa; Campos, Encarna; Dalmau, Manel; Illán, Patricia; Sánchez-Leal, Joaquin

    2006-02-01

    The effect of the inoculum source on the digestion of linear alkylbenzene sulfonates (LAS) under anaerobic conditions has been investigated. The potential for primary and ultimate LAS biodegradation of anaerobic sludge samples obtained from wastewater treatment plants (WWTPs) of different geographical locations was studied applying a batch test system. It was found that only 4-22% of the LAS added to the batch anaerobic digesters was primarily transformed suggesting a poor primary degradation of the LAS molecule in anaerobic discontinuous systems. Regarding ultimate biodegradation, the addition of LAS to the batch anaerobic digesters caused a reduction on the extent of biogas production. Significant differences in the inhibition extent of the biogas production were observed (4-26%) depending on the sludge used as inoculum. Effect of the surfactant on the anaerobic microorganisms was correlated with its concentration in the aqueous phase. Sorption of LAS on anaerobic sludge affects its toxicity by depletion of the available fraction of the surfactant. LAS content on sludge was related to the total amount of calcium and magnesium extractable ions. The presence of divalent cations promote the association of LAS with anaerobic sludge reducing its bioavailability and the extent of its inhibitory effect on the biogas production. PMID:16453170

  11. INVESTIGATING ANAEROBIC MICROBIAL PROCESSES IN AGRICULTURAL SOILS USING ANAEROMYXOBACTER DEHALOGENANS AS A COSMOPOLITAN MODEL [ABSTRACT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic microbial processes have not been thoroughly studied in agricultural soils. Yet, anaerobic conditions may significantly impact agrochemical fate, nutrient cycling, and plant/seed-microbe interactions. As part of a broader weed ecology/weed management experimental program we have selected...

  12. Whole farm impact of anaerobic digestion and biogas use on a New York dairy farm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic digestion of manure for biogas production is one of many options for reducing the carbon footprint of milk production. This process reduces greenhouse gas emissions but increases the potential nitrogen and phosphorus losses from the farm. An anaerobic digester component was added to the In...

  13. Evaluation of biogas production by dry anaerobic digestion of switchgrass-animal manure mixtures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic digestion is a biological method used to convert organic wastes into a stable product for land application without adverse environmental effects. The biogas produced can be used as an alternative renewable energy source. Dry anaerobic digestion (> 15% TS; total solid) has an advantage ov...

  14. Draft Genome of Thermanaerothrix daxensis GNS-1, a Thermophilic Facultative Anaerobe from the Chloroflexi Class Anaerolineae

    PubMed Central

    Pace, Laura A.; Ward, Lewis M.; Fischer, Woodward W.

    2015-01-01

    We present the draft genome of Thermanaerothrix daxensis GNS-1, a thermophilic member of the Chloroflexi phylum. This organism was initially characterized as a nonmotile, strictly anaerobic fermenter; however, genome analysis demonstrates that it encodes genes for a flagellum and multiple pathways for aerobic and anaerobic respiration. PMID:26586891

  15. Draft Genome of Thermanaerothrix daxensis GNS-1, a Thermophilic Facultative Anaerobe from the Chloroflexi Class Anaerolineae.

    PubMed

    Pace, Laura A; Hemp, James; Ward, Lewis M; Fischer, Woodward W

    2015-01-01

    We present the draft genome of Thermanaerothrix daxensis GNS-1, a thermophilic member of the Chloroflexi phylum. This organism was initially characterized as a nonmotile, strictly anaerobic fermenter; however, genome analysis demonstrates that it encodes genes for a flagellum and multiple pathways for aerobic and anaerobic respiration. PMID:26586891

  16. The Effect of Enzyme Addition on Anaerobic Digestion of Jose Tall Wheat Grass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of the addition of enzyme products containing cellulase, hemicellulase, and Beta-glucosidase to anaerobic digestion systems were studied. Anaerobic digestion tests were performed using batch reactors operated at 35°C. The application of enzyme products in three digestion configurations w...

  17. Isolation and characterisation of non-anaerobic butanol-producing symbiotic system TSH06.

    PubMed

    Wang, Genyu; Wu, Pengfei; Liu, Ya; Mi, Shuo; Mai, Shuai; Gu, Chunkai; Wang, Gehua; Liu, Hongjuan; Zhang, Jianan; Børresen, Børre Tore; Mellemsæther, Evy; Kotlar, Hans Kristian

    2015-10-01

    Butanol-producing microorganisms are all obligate anaerobes. In this study, a unique symbiotic system TSH06 was isolated to be capable of producing butanol under non-anaerobic condition. Denaturing gradient gel electrophoresis (DGGE) analysis of 16S ribosomal RNA (rRNA) revealed that two strains coexist in TSH06. The two strains were identical to Clostridium acetobutylicum and Bacillus cereus, respectively. They were isolated individually and named as C. acetobutylicum TSH1 and B. cereus TSH2. C. acetobutylicum TSH1 is a butanol-producing, obligate anaerobic strain. Facultative anaerobic B. cereus TSH2 did not possess the ability of butanol production; however, it offered C. acetobutylicum TSH1 the viability under non-anaerobic condition. Moreover, B. cereus TSH2 enhanced butanol yield and speed of fermentation. TSH06 produced 12.97 g/L butanol and 15.39 g/L total solvent under non-anaerobic condition, which is 25 and 24 %, respectively, higher than those of C. acetobutylicum TSH1. In addition, TSH06 produced butanol faster under non-anaerobic condition than under anaerobic condition. Butanol accounted for more than 80 % of total solvent, which is higher than the known report. TSH06 was stable during passage. In all, TSH06 is a promising candidate for industrialisation of biobutanol with high yield, high butanol proportion, easy-handling and time-saving system. These results demonstrated the potential advantage of symbiosis. This study also provides a promising strategy for butanol fermentation. PMID:26272091

  18. FUEL CELL OPERATION ON ANAEROBIC DIGESTER GAS: CONCEPTUAL DESIGN AND ASSESSMENT

    EPA Science Inventory

    The conceptual design of a fuel cell (FC) system for operation on anaerobic digester gas (ADG) is described and its economic and environmental feasibility is projected. ADG is produced at water treatment plants during the process of treating sewage anaerobically to reduce solids....

  19. ANAEROBIC BIODEGRADATION OF 2,4-DICHLOROPHENOL IN FRESHWATER LAKE SEDIMENTS AT DIFFERENT TEMPERATURES

    EPA Science Inventory

    Anaerobic degradation of 2,4-dichlorophenol (2,4-DCP) between 5 and 72C was investigated. naerobic sediment slurries prepared from local freshwater sediments were partitioned into anaerobic tubes or serum vials, which then were incubated separately at the various temperatures. ed...

  20. Effects of anaerobic digestion and aerobic treatment on gaseous emissions from dairy manure storages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of anaerobic digestion and aerobic treatment on the reduction of gaseous emissions from dairy manure storages were evaluated in this study. Screened dairy manure containing 3.5% volatile solids (VS) was either anaerobically digested or aerobically treated prior to storage in air-tight vessel...

  1. IMPACTS OF IRON, NUTRIENTS, AND MINERAL FINES ON ANAEROBIC BIODEGRADATION OF CANOLA OIL IN FRESHWATER SEDIMENTS

    EPA Science Inventory

    Factors affecting anaerobic biodegradation kinetics of canola oil in freshwater sediments were investigated. An optimum dose of ferric hydroxide (10.5 g Fe(III)·kg-1 sediment) was found to stimulate anaerobic biodegradation of canola oil (18.6 g oil kg-1). ...

  2. Anaerobic Digestion I. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    ERIC Educational Resources Information Center

    Arasmith, E. E.

    This lesson is the first of a two-part series on anaerobic digestion. Topics discussed include the five basic functions of an anaerobic digester, basic theory of the biological processes involved, basic equipment necessary for digestion, and the products of digestion. The lesson includes an instructor's guide and student workbook. The instructor's…

  3. Toxicity assessment of anaerobic digestion intermediates and antibiotics in pharmaceutical wastewater by luminescent bacterium.

    PubMed

    Ji, Jun-Yuan; Xing, Ya-Juan; Ma, Zi-Tao; Cai, Jing; Zheng, Ping; Lu, Hui-Feng

    2013-02-15

    In order to evaluate the effect of anaerobic digestion intermediates and antibiotics in pharmaceutical wastewaters on anaerobic digestion process, their acute toxicities were tested using the 15 min median inhibitory concentration (IC(50)) at pH 7.00 ± 0.05. The results showed that the IC(50) of ethanol, acetate, propionate and butyrate were 19.40, 20.71, 10.47 and 12.17 g L(-1) respectively, which suggested the toxicity descended in the order of propionate, butyrate, ethanol and acetate. The IC(50) of aureomycin, polymyxin and chloromycetin were 12.06, 6.24 and 429.90 mg L(-1) respectively, which indicated the toxicity descended in the order of polymyxin, aureomycin and chloromycetin. Using equitoxic ratio mixing method, the joint toxicities of five groups referred by A (four anaerobic digestion intermediates), B (four anaerobic digestion intermediates and aureomycin), C (four anaerobic digestion intermediates and polymyxin), D (four anaerobic digestion intermediates and chloromycetin) and E (four anaerobic digestion intermediates, aureomycin, polymyxin and chloromycetin) were investigated respectively. Their interactions were additive (A), synergistic (B), additive (C), synergistic (D) and synergistic (E). The investigation would lay a basis for the optimization of anaerobic biotechnology for pharmaceutical wastewater treatment. PMID:23334482

  4. The Relationship between Field Tests of Anaerobic Power and 10-km Run Performance.

    ERIC Educational Resources Information Center

    Sinnett, Aaron M.; Berg, Kris; Latin, Richard W.; Noble, John M.

    2001-01-01

    Investigated the relationship between several field tests of anaerobic power (e.g., +various sprints, vertical jumps, and a plyometric leap) and distance running performance in trained adult male and female runners. Results indicate that anaerobic power is significantly related to distance running performance and may explain a meaningful…

  5. Anaerobic soil disinfestation impact on nutrient dynamics in fresh-market tomato

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic soil disinfestation (ASD) is considered a promising sustainable alternative to chemical soil fumigation (CSF). Suitable for both organic and conventional growing systems. The soil amendment with organic material and its anaerobic decomposition cause a temporary variation of the soil redox...

  6. DEMONSTRATION BULLETIN: EX-SITU ANAEROBIC BIOREMEDIATION TECHNOLOGY - TNT - J.R. SIMPLOT COMPANY

    EPA Science Inventory

    The J. R. Simplot Ex-Situ Anaerobic Bioremediation System, also known as the J.R. Simplot Anaerobic Biological Remediaton Process (the SABRE™ Process), is a technology designed to destroy nitroaromatic and energetic compounds. The process does not evolve any known toxic intermedi...

  7. Anaerobic degradation of toluene by a denitrifying bacterium.

    PubMed Central

    Evans, P J; Mang, D T; Kim, K S; Young, L Y

    1991-01-01

    A denitrifying bacterium, designated strain T1, that grew with toluene as the sole source of carbon under anaerobic conditions was isolated. The type of agar used in solid media and the toxicity of toluene were determinative factors in the successful isolation of strain T1. Greater than 50% of the toluene carbon was oxidized to CO2, and 29% was assimilated into biomass. The oxidation of toluene to CO2 was stoichiometrically coupled to nitrate reduction and denitrification. Strain T1 was tolerant of and grew on 3 mM toluene after a lag phase. The rate of toluene degradation was 1.8 mumol min-1 liter-1 (56 nmol min-1 mg of protein-1) in a cell suspension. Strain T1 was distinct from other bacteria that oxidize toluene anaerobically, but it may utilize a similar biochemical pathway of oxidation. In addition, o-xylene was transformed to a metabolite in the presence of toluene but did not serve as the sole source of carbon for growth of strain T1. This transformation was dependent on the degradation of toluene. Images PMID:2059037

  8. Multi-fed upflow anaerobic filter: Development and features

    SciTech Connect

    Punal, A.; Mendez, R.; Lema, J.M.

    1998-12-01

    To overcome two of the main problems intrinsic to upflow anaerobic filters used to treat industrial waste water, clogging and poor efficiency in the upper zone, a new feeding strategy consisting of distributing the influent flow through several entrances along the system was studied. Two identical upflow anaerobic filters, a single-fed reactor (SFR) and a multi-fed reactor (MFR), were used with synthetic substrate of {approximately}10-kg chemical oxygen demand (COD)/m{sup 3} at an organic loading rate of up to 32-kg COD/m{sup 3} {center_dot} day. After more than 1 year of operation, the MFR strategy proved to be more efficient than the SFR, in terms of COD removal as well as with regard to stability against hydraulic and organic overloads. The MFR developed a more homogeneous bacteria consortium throughout the filter, therefore the specific methanogenic and nonmethanogenic activities are very similar in the bottom and the upper part of the filter. The MFR does not need a recycling flow to increase mixing. Moreover, the working volume of the MFR was higher than 85%, while only 65% of SFR remained active after 4310 days.

  9. Biogas generation in anaerobic wastewater treatment under tetracycline antibiotic pressure

    PubMed Central

    Lu, Meiqing; Niu, Xiaojun; Liu, Wei; Zhang, Jun; Wang, Jie; Yang, Jia; Wang, Wenqi; Yang, Zhiquan

    2016-01-01

    The effect of tetracycline (TC) antibiotic on biogas generation in anaerobic wastewater treatment was studied. A lab-scale Anaerobic Baffled Reactor (ABR) with three compartments was used. The reactor was operated with synthetic wastewater in the absence of TC and in the presence of 250 μg/L TC for 90 days, respectively. The removal rate of TC, volatile fatty acids (VFAs), biogas compositions (hydrogen (H2), methane (CH4), carbon dioxide (CO2)), and total biogas production in each compartment were monitored in the two operational conditions. Results showed that the removal rate of TC was 14.97–67.97% in the reactor. The presence of TC had a large negative effect on CH4 and CO2 generation, but appeared to have a positive effect on H2 production and VFAs accumulation. This response indicated that the methanogenesis process was sensitive to TC presence, but the acidogenesis process was insensitive. This suggested that the presence of TC had less influence on the degradation of organic matter but had a strong influence on biogas generation. Additionally, the decrease of CH4 and CO2 generation and the increase of H2 and VFAs accumulation suggest a promising strategy to help alleviate global warming and improve resource recovery in an environmentally friendly approach. PMID:27341657

  10. Anaerobic phenol degradation by microorganisms of swine manure.

    SciTech Connect

    Boopathy, R.; Environmental Research

    1997-01-01

    Swine manure contains diverse groups of aerobic and anaerobic bacteria. An anaerobic bacterial consortium containing sulfate-reducing bacteria (SRB) and acetate-utilizing methanogenic bacteria was isolated from swine manure. This consortium used phenol as its sole source of carbon and converted it to methane and CO{sub 2}. The sulfate-reducing bacterial members of the consortium are the incomplete oxidizers, unable to carry out the terminal oxidation of organic substrates, leaving acetic acid as the end product. The methanogenic bacteria of the consortium converted the acetic acid to methane. When a methanogen inhibitor was used in the culture medium, phenol was converted to acetic acid by the SRB, but the acetic acid did not undergo further metabolism. On the other hand, when the growth of SRB in the consortium was suppressed with a specific SRB inhibitor, namely, molybdenum tetroxide, the phenol was not degraded. Thus, the metabolic activities of both the sulfate-reducing bacteria and the methanogenic bacteria were essential for complete degradation of phenol.

  11. Biogas generation in anaerobic wastewater treatment under tetracycline antibiotic pressure.

    PubMed

    Lu, Meiqing; Niu, Xiaojun; Liu, Wei; Zhang, Jun; Wang, Jie; Yang, Jia; Wang, Wenqi; Yang, Zhiquan

    2016-01-01

    The effect of tetracycline (TC) antibiotic on biogas generation in anaerobic wastewater treatment was studied. A lab-scale Anaerobic Baffled Reactor (ABR) with three compartments was used. The reactor was operated with synthetic wastewater in the absence of TC and in the presence of 250 μg/L TC for 90 days, respectively. The removal rate of TC, volatile fatty acids (VFAs), biogas compositions (hydrogen (H2), methane (CH4), carbon dioxide (CO2)), and total biogas production in each compartment were monitored in the two operational conditions. Results showed that the removal rate of TC was 14.97-67.97% in the reactor. The presence of TC had a large negative effect on CH4 and CO2 generation, but appeared to have a positive effect on H2 production and VFAs accumulation. This response indicated that the methanogenesis process was sensitive to TC presence, but the acidogenesis process was insensitive. This suggested that the presence of TC had less influence on the degradation of organic matter but had a strong influence on biogas generation. Additionally, the decrease of CH4 and CO2 generation and the increase of H2 and VFAs accumulation suggest a promising strategy to help alleviate global warming and improve resource recovery in an environmentally friendly approach. PMID:27341657

  12. Anaerobic threshold: the concept and methods of measurement.

    PubMed

    Svedahl, Krista; MacIntosh, Brian R

    2003-04-01

    The anaerobic threshold (AnT) is defined as the highest sustained intensity of exercise for which measurement of oxygen uptake can account for the entire energy requirement. At the AnT, the rate at which lactate appears in the blood will be equal to the rate of its disappearance. Although inadequate oxygen delivery may facilitate lactic acid production, there is no evidence that lactic acid production above the AnT results from inadequate oxygen delivery. There are many reasons for trying to quantify this intensity of exercise, including assessment of cardiovascular or pulmonary health, evaluation of training programs, and categorization of the intensity of exercise as mild, moderate, or intense. Several tests have been developed to determine the intensity of exercise associated with AnT: maximal lactate steady state, lactate minimum test, lactate threshold, OBLA, individual anaerobic threshold, and ventilatory threshold. Each approach permits an estimate of the intensity of exercise associated with AnT, but also has consistent and predictable error depending on protocol and the criteria used to identify the appropriate intensity of exercise. These tests are valuable, but when used to predict AnT, the term that describes the approach taken should be used to refer to the intensity that has been identified, rather than to refer to this intensity as the AnT. PMID:12825337

  13. Microbial Electrochemical Monitoring of Volatile Fatty Acids during Anaerobic Digestion.

    PubMed

    Jin, Xiangdan; Angelidaki, Irini; Zhang, Yifeng

    2016-04-19

    Volatile fatty acid (VFA) concentration is known as an important indicator to control and optimize anaerobic digestion (AD) process. In this study, an innovative VFA biosensor was developed based on the principle of a microbial desalination cell. The correlation between current densities and VFA concentrations was first evaluated with synthetic digestate. Two linear relationships were observed between current densities and VFA levels from 1 to 30 mM (0.04 to 8.50 mA/m(2), R(2) = 0.97) and then from 30 to 200 mM (8.50 to 10.80 mA/m(2), R(2) = 0.95). The detection range was much broader than that of other existing VFA biosensors. The biosensor had no response to protein and lipid which are frequently found along with VFAs in organic waste streams from AD, suggesting the selective detection of VFAs. The current displayed different responses to VFA levels when different ionic strengths and external resistances were applied, though linear relationships were always observed. Finally, the biosensor was further explored with real AD effluents and the results did not show significance differences with those measured by GC. The simple and efficient biosensor showed promising potential for online, inexpensive, and reliable measurement of VFA levels during AD and other anaerobic processes. PMID:27054267

  14. Effect of pectin on anaerobic digestion of cattle dung

    SciTech Connect

    Madamwar, D.B.; Mithal, B.M.

    1986-04-01

    It is therefore desirable to discover procedures to increase the rate of digestion. It has been reported that addition of powdered activated carbon results in an increase in total gas production with high methane content. Based on a review of the literature, it is evident that carbon is responsible for improved digestion. The surface of the activated carbon provides adsorption sites where substrate can accumulate, thereby providing high localized substrate concentration. These areas of adsorption provide a more favorable growth environment for bacterial-substrate systems. No study, however, seems to have been made so far on the effect of other additives like pectin on anaerobic digestion of cattle dung. Since pectin is also used as one of the adsorbents in many cases, it appears desirable to study the effect of pectin on anaerobic digestion of cattle dung with the ultimate aim of improving the production of gas with increased methane content. Experiments carried out with this object in view are reported in this paper. The impact of pectin on volatile acid, pH, and process stability has also been examined. This paper presents the results of two sets of experiments involving pectin addition to bench-scale digesters. One set of experiments is carried out at a controlled temperature of 38 +/- 1 degree C, while the other is carried out at ambient temperature-ambient temperature varied from 40 to 15 degrees C, that is from August to November. 14 references.

  15. Anaerobic microbial dissolution of lead and production of organic acids

    DOEpatents

    Francis, A.J.; Dodge, C.; Chendrayan, K.; Quinby, H.L.

    1987-04-16

    The present invention related to an anaerobic bacterial culture of Clostridium sp. ATCC No. 53464 which solubilizes lead oxide under anaerobic conditions in coal and industrial wastes and therefore presents a method of removing lead from such wastes before they are dumped into the environment. The rat of lead dissolution during logarithmic growth of the bacteria in 40 ml medium containing 3.32 ..mu..moles of lead as lead oxide was 0.042 ..mu..moles m1/sup /-/1/ hr/sup /-/1/. Dissolution of lead oxide by the bacterial isolate is due to the production of metabolites and acidity in the culture medium. The major metabolites are acetic, butyric and lactic acid. The major metabolites are acetic, butyric and lactic acid. Clostridium sp. ATCC No. 53464 can be used in the recovery of the strategic metals from ores and wastes and also for the production of lactic acid for commercial purposes. The process yields large quantities of lactic acid as well as lead complexed in a stable form with said acids. 4 figs., 3 tabs.

  16. Anaerobic microbial dissolution of lead and production of organic acids

    DOEpatents

    Francis, Arokiasamy J.; Dodge, Cleveland; Chendrayan, Krishnachetty; Quinby, Helen L.

    1988-01-01

    The present invention relates to an anaerobic bacterial culture of Clostridium sp. ATCC No. 53464 which solubilizes lead oxide under anaerobic conditions in coal and industrial wastes and therefore presents a method of removing lead from such wastes before they are dumped into the environment. The rate of lead dissolution during logarithmic growth of the bacteria in 40 ml medium containing 3.32 .mu.moles of lead as lead oxide was 0.042 .mu.moles ml.sup.-1 hr.sup.-1. Dissolution of lead oxide by the bacterial isolate is due to the production of metabolites and acidity in the culture medium. The major metabolites are acetic, butyric and lactic acid. Clostridium sp. ATCC No. 53464 can be used in the recovery of strategic metals from ores and wastes and also for the production of lactic acid for commercial purposes. The process yields large quantities of lactic acid as well as lead complexed in a stable form with said acids.

  17. Anaerobic biodegradation of estrogens--hard to digest.

    PubMed

    de Mes, T Z D; Kujawa-Roeleveld, K; Zeeman, G; Lettinga, G

    2008-01-01

    Although many publications are available on the fate of estrone (E1), 17beta-estradiol (E2) and 17alpha-ethynylestradiol (EE2) during aerobic wastewater treatment, little is published on their fate under strictly anaerobic conditions. Present research investigated the digestibility of E1 and EE2, using digested pig manure, granular UASB sludge, UASB-septic tank sludge and activated sludge as inocula. Besides, actual concentrations were measured in a UASB septic tank treating black water. Under anaerobic conditions E1 is reduced to E2 but the extent of this reduction depends on type of inoculum. No significant loss of the sum of E1 and E2 and of EE2 was observed. Adsorption was responsible for a 32-35% loss of E1 and E2 from the liquid phase in the UASB septic tank and the effluent still contained considerable concentrations of respectively 4.02 microg/l and 18.79 microg/l for E1 and E2 with a large fraction present in conjugated form. No EE2 was detected in the UASB effluent. PMID:18469388

  18. Kinetics of inactivation of indicator pathogens during thermophilic anaerobic digestion.

    PubMed

    Popat, Sudeep C; Yates, Marylynn V; Deshusses, Marc A

    2010-12-01

    Thermophilic anaerobic sludge digestion is a promising process to divert waste to beneficial use, but an important question is the required temperature and holding time to achieve a given degree of pathogen inactivation. In this study, the kinetics of inactivation of Ascaris suum and vaccine strain poliovirus type 1 (PVS-1), selected as indicators for helminth ova and enteric viruses respectively, were determined during anaerobic digestion at temperatures ranging from 51 to 56 °C. Inactivation of both indicator organisms was fast with greater than two log reductions achieved within 2 h for A. suum and three log reductions for PVS-1, suggesting that the current U.S. regulations are largely conservative. The first-order inactivation rate constants k followed Arrhenius relationship with activation energies of 105 and 39 KJ mol(-1) for A. suum and PVS-1, respectively indicating that A. suum was more sensitive to temperature. Although inactivation was fast, the presence of compounds in the sludge that are known to be protective of pathogen inactivation was observed, suggesting that composition-dependent time-temperature relationships are necessary. PMID:20692678

  19. Study of Resource Recovery and Epidemiology in an Anaerobic Digester

    NASA Technical Reports Server (NTRS)

    Li, K. Y.; Cao, Song; Hunt, M. D.; Fu, Xuping

    1995-01-01

    Three 4-liter packed bed anaerobic digesters were fabricated and operated at 35 degrees C, pH around 7, and hydraulic retention time (HRT) of 20, 10 and 5 days to study the resource recovery and epidemiology in a controlled ecological life support system (CELSS). A simulated wastewater, consisted of shower water, clothwash water, dishwasher water, handwash water, and urine flush water was used as the feeding solution. Under steady-state operation, chemical oxygen demand (COD), total organic carbon (TOC), pH, nitrogen, phosphorus, and potassium wer monitored in the digester input and output solutions. The volume and the CH4/CO2 ratios in the biogas produced from the anaerobic digesters were measured. The results indicate about 90 percent of TOC is converted while only 5-8 percent of N-P-K are consumed in the digester. A multi-drug resistant strain of Salmonella choleraesuis was used as the indicator bacterium in the epidemiology study. The levels of Salmonella choleraesuis in the influent and the effluent wer determined and decimal decay rate constants, k(d), were estimated. The k(d) values were greater at higher initial doses than lower doses for the same HR, and greater for batch digestion (7.89/d) than for continuous digestion (4.28, 3.82, and 3.82/d for 20, 10, and 5 d HRT, respectively).

  20. Anaerobic Biodegradation of Pristane by Nitrate Reducing Bacteria

    NASA Astrophysics Data System (ADS)

    Dawson, K. S.; Freeman, K. H.; Macalady, J. L.

    2007-12-01

    In recent sediments, microbial biodegradation provides a control on the long-term preservation of organic matter, through the preferential loss of certain biomolecules and the alteration and concentration of other more recalcitrant molecules. Biodegradation of hydrocarbons derived from membrane lipids, has been demonstrated by both aerobic and strictly anaerobic culturing experiments. The isoprenoid pristane, once considered stable under anaerobic conditions, is in fact degraded by a denitrifying microcosm (BREGNARD et al., 1997) and a methanogenic, sulphate-reducing enrichment culture (GROSSI, 2000). We recently demonstrated pristane biodegradation and accompanying loss of nitrate by an activated sludge isolate. The measured nitrate consumption accounts for a 7.1 +/- 0.4 mg loss of pristane, 4.74% of the initial substrate, in 181 days, assuming pristane conversion to CO2. We have characterized the microorganisms active in the biodegradation process, through the creation of a 16S rDNA clone library, as well as fluorescence in situ hybridization (FISH). Experiments are in progress to enrich cultures of sulfate reducing bacteria that utilize pristane as a sole carbon source and to characterize reaction mechanisms in pristane-oxidizing pathways.

  1. Numerical modeling of oxygen exclusion experiments of anaerobic bioventing.

    PubMed

    Mihopoulos, Philip G; Suidan, Makram T; Sayles, Gregory D; Kaskassian, Sebastien

    2002-10-01

    A numerical and experimental study of transport phenomena underlying anaerobic bioventing (ABV) is presented. Understanding oxygen exclusion patterns in vadose zone environments is important in designing an ABV process for bioremediation of soil contaminated with chlorinated solvents. In particular, the establishment of an anaerobic zone of influence by nitrogen injection in the vadose zone is investigated. Oxygen exclusion experiments are performed in a pilot scale flow cell (2 x 1.1 x 0.1 m) using different venting flows and two different outflow boundary conditions (open and partially covered). Injection gas velocities are varied from 0.25 x 10(-3) to 1.0 x 10(-3) cm/s and are correlated with the ABV radius of influence. Numerical simulations are used to predict the collected experimental data. In general, reasonable agreement is found between observed and predicted oxygen concentrations. Use of impervious covers can significantly reduce the volume of forcing gas used, where an increase in oxygen exclusion efficiency is consistent with a decrease in the outflow area above the injection well. PMID:12400833

  2. Noncatalytic docking domains of cellulosomes of anaerobic fungi.

    PubMed

    Steenbakkers, P J; Li, X L; Ximenes, E A; Arts, J G; Chen, H; Ljungdahl, L G; Op Den Camp, H J

    2001-09-01

    A method is presented for the specific isolation of genes encoding cellulosome components from anaerobic fungi. The catalytic components of the cellulosome of anaerobic fungi typically contain, besides the catalytic domain, mostly two copies of a 40-amino-acid cysteine-rich, noncatalytic docking domain (NCDD) interspaced by short linkers. Degenerate primers were designed to anneal to the highly conserved region within the NCDDs of the monocentric fungus Piromyces sp. strain E2 and the polycentric fungus Orpinomyces sp. strain PC-2. Through PCR using cDNA from Orpinomyces sp. and genomic DNA from Piromyces sp. as templates, respectively, 9 and 19 PCR products were isolated encoding novel NCDD linker sequences. Screening of an Orpinomyces sp. cDNA library with four of these PCR products resulted in the isolation of new genes encoding cellulosome components. An alignment of the partial NCDD sequence information obtained and an alignment of database-accessible NCDD sequences, focusing on the number and position of cysteine residues, indicated the presence of three structural subfamilies within fungal NCDDs. Furthermore, evidence is presented that the NCDDs in CelC from the polycentric fungus Orpinomyces sp. strain PC-2 specifically recognize four proteins in a cellulosome preparation, indicating the presence of multiple scaffoldins. PMID:11514516

  3. Genome sequence of the stramenopile Blastocystis, a human anaerobic parasite

    PubMed Central

    2011-01-01

    Background Blastocystis is a highly prevalent anaerobic eukaryotic parasite of humans and animals that is associated with various gastrointestinal and extraintestinal disorders. Epidemiological studies have identified different subtypes but no one subtype has been definitively correlated with disease. Results Here we report the 18.8 Mb genome sequence of a Blastocystis subtype 7 isolate, which is the smallest stramenopile genome sequenced to date. The genome is highly compact and contains intriguing rearrangements. Comparisons with other available stramenopile genomes (plant pathogenic oomycete and diatom genomes) revealed effector proteins potentially involved in the adaptation to the intestinal environment, which were likely acquired via horizontal gene transfer. Moreover, Blastocystis living in anaerobic conditions harbors mitochondria-like organelles. An incomplete oxidative phosphorylation chain, a partial Krebs cycle, amino acid and fatty acid metabolisms and an iron-sulfur cluster assembly are all predicted to occur in these organelles. Predicted secretory proteins possess putative activities that may alter host physiology, such as proteases, protease-inhibitors, immunophilins and glycosyltransferases. This parasite also possesses the enzymatic machinery to tolerate oxidative bursts resulting from its own metabolism or induced by the host immune system. Conclusions This study provides insights into the genome architecture of this unusual stramenopile. It also proposes candidate genes with which to study the physiopathology of this parasite and thus may lead to further investigations into Blastocystis-host interactions. PMID:21439036

  4. Repeated pulse feeding induces functional stability in anaerobic digestion

    PubMed Central

    De Vrieze, Jo; Verstraete, Willy; Boon, Nico

    2013-01-01

    Summary Anaerobic digestion is an environmental key technology in the future bio-based economy. To achieve functional stability, a minimal microbial community diversity is required. This microbial community should also have a certain ‘elasticity’, i.e. the ability to rapidly adapt to suboptimal conditions or stress. In this study it was evaluated whether a higher degree of functional stability could be achieved by changing the feeding pattern, which can change the evenness, dynamics and richness of the bacterial community. The first reactor (CSTRstable) was fed on daily basis, whereas the second reactor (CSTRdynamic) was fed every 2 days. Average biogas production was 0.30 l CH4 l−1 day−1 in both reactors, although daily variation was up to four times higher in the CSTRdynamic compared with the CSTRstable during the first 50 days. Bacterial analysis revealed that this CSTRdynamic had a two times higher degree of bacterial community dynamics. The CSTRdynamic also appeared to be more tolerant to an organic shock load of 8 g COD l−1 and ammonium levels up to 8000 mg TAN l−1. These results suggest that the regular application of a limited pulse of organic material and/or a variation in the substrate composition might promote higher functional stability in anaerobic digestion. PMID:23302421

  5. Inhibition of anaerobic digestion by organic priority pollutants

    SciTech Connect

    Johnson, L.D.

    1981-01-01

    Process instability caused by toxic inhibition is a major problem with anaerobic waste treatment systems. A batch bioassay technique was used to determine inhibitory effects from the twenty-four representative organic pollutants selected for testing. Only seven produced significant inhibition of gas production at concentrations of 100 mg/l or less. These seven were (a) nitrobenzene, (b) 4-nitrophenol, (c) 2-nitrophenol, (d) hexachloroethane, (e) hexachlorocyclopentadiene, (f) 2,4-dichlorophenol, and (g) hexachloro-1,3-butadiene. Reversible inhibition was observed for all of these except (f) and (g). The recovery of methane production inhibited by the nitro organics was due to biological reduction of the nitro group to a relatively nontoxic amine group. Recovery of gas production in cultures inhibited by (d) was due to acclimation of the microorganisms to the low concentrations of this compound remaining in solution after removal by adsorption onto the solids in the cultures. A combination of adsorption and anaerobic dechlorination of (e) caused the removal of this compound from solution and thus the recovery of gas production. The concentration of (g) was significantly reduced by adsorption, but gas production did not recover in cultures inhibited by this compound.

  6. Anaerobic removal of pentachlorophenol in presence of zinc

    SciTech Connect

    Jin, P.; Bhattacharya, S.K.

    1996-07-01

    The objective of this research was to determine the toxic effects and degradation of pentachlorophenol (PCP) in the presence of zinc in anaerobic propionate systems. Anaerobic toxicity assays (ATA), batch kinetic studies, and biodegradation studies were performed using serum bottles. PCP inhibition was modeled using both uncompetitive and noncompetitive inhibition kinetic models with an inhibition coefficient, K{sub I}, of 0.06 mg/L. Zinc toxicity showed that the competitive inhibition model was the best-fit with a K{sub I} of 1.1 mg/L. A combined competitive-uncompetitive inhibition model was the best-fit model in the presence of both PCP and zinc for propionate degradation. In the biodegradation studies, PCP removals were 72, 64, and 54% with spiked PCP concentrations of 2, 3, and 5 mg/L, respectively. In the presence of zinc, the removal of 2 mg/L and 3 mg/L of PCP decreased to 60% and 53%, respectively. The intermediates of PCP degradation were 2,4,6-trichlorophenol, 2,4-dichlorophenol, 4-chlorophenol, 2,3,5-trichlorophenol, 3,5-dichlorophenol, and 3-chlorophenol; lower concentrations of these intermediates were observed in the presence of zinc.

  7. Anaerobic biogranulation using phenol as the sole carbon source

    SciTech Connect

    Tay, J.H.; He, Y.X.; Yan, Y.G.

    2000-04-01

    The granulation process was extensively examined using phenol as sole carbon source in a 2-L laboratory upflow anaerobic sludge blanket (UASB) reactor. The study was conducted mesophilically at 35 C. Anaerobically digested sludge was used as seed after a 14-day activation period with glucose feed. Massive initial granules were developed after 3 months of startup, grew at an accelerated pace for 6 months, then became fully grown. The granulation process can be broken into three phases: acclimation, granulation, and maturation. However, granulation with phenol proceeded more slowly than it did in UASB reactors fed with readily biodegradable carbohydrates studied previously. The granular sludge cultivated had a median diameter of 1.8 mm, phenol-degrading activity of 0.65 g chemical oxygen demand (COD)/g volatile suspended solids (VSS){sm_bullet}d, and a sludge volume index of 14 mL/g. Phenol COD removal efficiency of 86% was achieved when the reactor was operating at an influent phenol concentration of 1,260 mg/L (corresponding to 3,000 mg COD/L), hydraulic retention time of 12 hours, and volumetric loading rate of 6 g COD/L{sm_bullet}d. However, the lower-than-expected phenol COD removal efficiency could be attributed to inhibition by the high influent phenol concentration or loading. The batch test demonstrated that the sludge methanogenic activity was reduced by 52 and 75% at phenol concentrations of 420 and 840 mg/L, respectively.

  8. Impact of paper and cardboard suppression on OFMSW anaerobic digestion.

    PubMed

    Fonoll, X; Astals, S; Dosta, J; Mata-Alvarez, J

    2016-10-01

    Mechanical-biological treatment plants treat municipal solid waste to recover recyclable materials, nutrients and energy. Waste paper and cardboard (WP), the second main compound in municipal solid waste (∼30% in weight basis), is typically used for biogas generation. However, its recovery is gaining attention as it can be used to produce add-value products like bioethanol and residual derived fuel. Nevertheless, WP suppression or replacement will impact anaerobic digestion in terms of biogas production, process stability and digestate management. Two lab-scale reactors were used to assess the impact of WP in anaerobic digestion performance. A control reactor was only fed with biowaste (BioW), while a second reactor was fed with two different mixtures of BioW and WP, i.e. 85/15% and 70/30% (weight basis). Results indicate that either replacing half of the WP by BioW or removing half of the WP has little impact on the methane production. When removing half of the WP, methane production could be sustained by a larger waste biodegradability. The replacement of all WP by BioW increased the reactor methane production (∼37%), while removing all WP would have reduced the methane production about 15%. Finally, replacing WP loading rate by BioW led to a system less tolerant to instability periods and with poorer digestate quality. PMID:27290631

  9. Comparison between ozone and ultrasound disintegration on sludge anaerobic digestion.

    PubMed

    Braguglia, C M; Gianico, A; Mininni, G

    2012-03-01

    This paper deals with the comparison of ultrasound (mechanical) and ozone (chemical) pre-treatment on the performances of excess sludge semi-continuous digestion. Sludge solubilisation has been investigated by varying specific energy input. For each pre-treatment, long anaerobic digestion tests were carried out by two parallel digesters: one reactor, as control unit, was fed with untreated waste activated sludge, and the other one was fed with disintegrated sludge. To evaluate and compare the efficacy of both pre-treatments, the specific energy was maintained approximately the same. The digestion tests were carried out to investigate the feasibility of anaerobic digestion performance (total biogas production, volatile solids removal, sludge dewaterability) and to assess the heat balance. Results obtained from the digestion of sonicated sludge at 4% disintegration degree (≈ 2500 kJ/kg TS) showed that the ultrasound pre-treatment may be effective both in increasing VS destruction (+19%) and cumulative biogas production (+26%). On the contrary, the digestion test with ozonized sludge (ozone dose of 0.05 g O(3)/g TS corresponding to ≈ 2000 kJ/kg TS) did not indicate a significant improvement on the digestion performances. By doubling the ozone dose an improvement in the organics removal and cumulative biogas production was observed. Relevant differences in terms of colloidal charge and filterability were discussed. PMID:20719427

  10. Degradation properties of protein and carbohydrate during sludge anaerobic digestion.

    PubMed

    Yang, Guang; Zhang, Panyue; Zhang, Guangming; Wang, Yuanyuan; Yang, Anqi

    2015-09-01

    Degradation of protein and carbohydrate is vital for sludge anaerobic digestion performance. However, few studies focused on degradation properties of protein and carbohydrate. This study investigated detailed degradation properties of sludge protein and carbohydrate in order to gain insight into organics removal during anaerobic digestion. Results showed that carbohydrate was more efficiently degraded than protein and was degraded prior to protein. The final removal efficiencies of carbohydrate and protein were 49.7% and 32.2%, respectively. The first 3 days were a lag phase for protein degradation since rapid carbohydrate degradation in this phase led to repression of protease formation. Kinetics results showed that, after initial lag phase, protein degradation followed the first-order kinetic with rate constants of 0.0197 and 0.0018 d(-1) during later rapid degradation phase and slow degradation phase, respectively. Carbohydrate degradation also followed the first-order kinetics with a rate constant of 0.007 d(-1) after initial quick degradation phase. PMID:26025350

  11. Anaerobic animals from an ancient, anoxic ecological niche

    PubMed Central

    2010-01-01

    Tiny marine animals that complete their life cycle in the total absence of light and oxygen are reported by Roberto Danovaro and colleagues in this issue of BMC Biology. These fascinating animals are new members of the phylum Loricifera and possess mitochondria that in electron micrographs look very much like hydrogenosomes, the H2-producing mitochondria found among several unicellular eukaryotic lineages. The discovery of metazoan life in a permanently anoxic and sulphidic environment provides a glimpse of what a good part of Earth's past ecology might have been like in 'Canfield oceans', before the rise of deep marine oxygen levels and the appearance of the first large animals in the fossil record roughly 550-600 million years ago. The findings underscore the evolutionary significance of anaerobic deep sea environments and the anaerobic lifestyle among mitochondrion-bearing cells. They also testify that a fuller understanding of eukaryotic and metazoan evolution will come from the study of modern anoxic and hypoxic habitats. PMID:20370917

  12. Fate of neptunium in an anaerobic, methanogenic microcosm.

    SciTech Connect

    Banaszak, J. E.

    1998-12-21

    Neptunium is found predominantly as Np(IV) in reducing environments, but Np(V) in aerobic environments. However, currently it is not known how the interplay between biotic and abiotic processes affects Np redox speciation in the environment. In order to evaluate the effect of anaerobic microbial activity on the fate of Np in natural systems, Np(V) was added to a microcosminoculated with anaerobic sediments from a metal-contaminated fresh water lake. The consortium included metal-reducing, sulfate-reducing, and methanogenic microorganisms, and acetate was supplied as the only exogenous substrate. Addition of more than 10{sup {minus}5} M Np did not inhibit methane production. Total Np volubility in the active microcosm, as well as in sterilized control samples, decreased by nearly two orders of magnitude. A combination of analytical techniques, including VIS-NIR absorption spectroscopy and XANES, identified Np(IV) as the oxidation state associated with the sediments. The similar results from the active microcosm and the abiotic controls suggest that microbian y produced Mn(II/HI) and Fe(II) may serve as electron donors for Np reduction.

  13. Chemical and physical differentiation of superoxide dismutases in anaerobes.

    PubMed Central

    Gregory, E M; Dapper, C H

    1980-01-01

    Superoxide dismutase activity in crude or partially purified cell extracts from several species and strains of obligate anaerobe Bacteroides was inhibited instantaneously by NaN3 and was inactivated rapidly upon incubation with H2O2. The extent of NaN3 inhibition varied from 41 to 93%, and the half-life of the enzymatic activity in 5 mM H2O2 ranged from 1.2 to 6.1 min, depending upon the organism tests. When grown in a defined medium containing 59Fe, Bacteroides fragilis (VPI 2393) incorporated radiolabel into a 40,000-molecular-weight NaN3- and H2O2-sensitive superoxide dismutase but did not incorporate 54Mn into that protein under similar growth conditions. The anaerobe Actinomyces naeslundii (VPI 9985) incorporated 54Mn but not 59Fe into a NaN3-insensitive and H2O2-resistant superoxide dismutase. The apparent molecular weight of the superoxide dismutase from this and several other Actinomyces spp. was estimated to be 110,000 to 140,000. Comparison of these data with studies of homogeneous metallosuperoxide dismutases suggests that the Bacteroides spp. studied contain a ferrisuperoxide dismutase, whereas Actinomyces spp. contain a managanisuperoxide dismutase. PMID:7440509

  14. A mass transfer model of ammonia volatilisation from anaerobic digestate

    SciTech Connect

    Whelan, M.J.; Everitt, T.; Villa, R.

    2010-10-15

    Anaerobic digestion (AD) is becoming increasingly popular for treating organic waste. The methane produced can be burned to generate electricity and the digestate, which is high in mineral nitrogen, can be used as a fertiliser. In this paper we evaluate potential losses of ammonia via volatilisation from food waste anaerobic digestate using a closed chamber system equipped with a sulphuric acid trap. Ammonia losses represent a pollution source and, over long periods could reduce the agronomic value of the digestate. Observed ammonia losses from the experimental system were linear with time. A simple non-steady-state partitioning model was developed to represent the process. After calibration, the model was able to describe the behaviour of ammonia in the digestate and in the trap very well. The average rate of volatilisation was approximately 5.2 g N m{sup -2} week{sup -1}. The model was used to extrapolate the findings of the laboratory study to a number of AD storage scenarios. The simulations highlight that open storage of digestate could result in significant losses of ammonia to the atmosphere. Losses are predicted to be relatively minor from covered facilities, particularly if depth to surface area ratio is high.

  15. Activation of Acetone and Other Simple Ketones in Anaerobic Bacteria.

    PubMed

    Heider, Johann; Schühle, Karola; Frey, Jasmin; Schink, Bernhard

    2016-01-01

    Acetone and other ketones are activated for subsequent degradation through carboxylation by many nitrate-reducing, phototrophic, and obligately aerobic bacteria. Acetone carboxylation leads to acetoacetate, which is subsequently activated to a thioester and degraded via thiolysis. Two different types of acetone carboxylases have been described, which require either 2 or 4 ATP equivalents as an energy supply for the carboxylation reaction. Both enzymes appear to combine acetone enolphosphate with carbonic phosphate to form acetoacetate. A similar but more complex enzyme is known to carboxylate the aromatic ketone acetophenone, a metabolic intermediate in anaerobic ethylbenzene metabolism in denitrifying bacteria, with simultaneous hydrolysis of 2 ATP to 2 ADP. Obligately anaerobic sulfate-reducing bacteria activate acetone to a four-carbon compound as well, but via a different process than bicarbonate- or CO2-dependent carboxylation. The present evidence indicates that either carbon monoxide or a formyl residue is used as a cosubstrate, and that the overall ATP expenditure of this pathway is substantially lower than in the known acetone carboxylase reactions. PMID:26958851

  16. Distinct carbon isotope fractionation during anaerobic degradation of dichlorobenzene isomers.

    PubMed

    Liang, Xiaoming; Mundle, Scott O C; Nelson, Jennifer L; Passeport, Elodie; Chan, Calvin C H; Lacrampe-Couloume, Georges; Zinder, Stephen H; Sherwood Lollar, Barbara

    2014-05-01

    Chlorinated benzenes are ubiquitous organic contaminants found in groundwater and soils. Compound specific isotope analysis (CSIA) has been increasingly used to assess natural attenuation of chlorinated contaminants, in which anaerobic reductive dechlorination plays an essential role. In this work, carbon isotope fractionation of the three dichlorobenzene (DCB) isomers was investigated during anaerobic reductive dehalogenation in methanogenic laboratory microcosms. Large isotope fractionation of 1,3-DCB and 1,4-DCB was observed while only a small isotope effect occurred for 1,2-DCB. Bulk enrichment factors (εbulk) were determined from a Rayleigh model: -0.8 ± 0.1 ‰ for 1,2-DCB, -5.4 ± 0.4 ‰ for 1,3-DCB, and -6.3 ± 0.2 ‰ for 1,4-DCB. εbulk values were converted to apparent kinetic isotope effects for carbon (AKIE) in order to characterize the carbon isotope effect at the reactive positions for the DCB isomers. AKIE values are 1.005 ± 0.001, 1.034 ± 0.003, and 1.039 ± 0.001 for 1,2-DCB, 1,3-DCB, and 1,4-DCB, respectively. The large difference in AKIE values between 1,2-DCB and 1,3-DCB (or 1,4-DCB) suggests distinct reaction pathways may be involved for different DCB isomers during microbial reductive dechlorination by the methanogenic cultures. PMID:24758692

  17. Anaerobic treatment of crude glycerol from biodiesel production.

    PubMed

    Nakazawa, M M; Silva Júnior, W R S; Kato, M T; Gavazza, S; Florencio, L

    2015-01-01

    In this study, we evaluated the use of an up-flow anaerobic sludge blanket (UASB) reactor to treat crude glycerol obtained from cottonseed biodiesel production. The laboratory-scale UASB reactor (7.0 L) was operated at ambient temperature of 26.5°C with chemical oxygen demand (COD) concentrations between 0.5 and 8.0 g/L. The volatile fatty acid contents, pH, inorganic salt contents and biogas production were monitored during a 280-day experimental period. Molecular biology techniques were used to assess the microbial diversity in the bioreactor. The reactor achieved COD removal efficiencies of up to 92% except during one phase when the efficiency decreased to 81%. Biogas production remained stable throughout the experimental period, when the fraction converted to methane reached values as high as 68%. The profile of the denaturing gradient gel electrophoresis (DGGE) bands suggested slight changes in the microbial community during reactor operation. The overall results indicated that the crude glycerol from biodiesel production can serve as a suitable substrate for anaerobic degradation with a stable reactor performance and biogas production as long as the applied organic loads are up to 8.06 kg COD/m3·d. PMID:26465309

  18. Anaerobic digestion analysis model: User`s manual

    SciTech Connect

    Ruth, M.; Landucci, R.

    1994-08-01

    The Anaerobic Digestion Analysis Model (ADAM) has been developed to assist investigators in performing preliminary economic analyses of anaerobic digestion processes. The model, which runs under Microsoft Excel{trademark}, is capable of estimating the economic performance of several different waste digestion process configurations that are defined by the user through a series of option selections. The model can be used to predict required feedstock tipping fees, product selling prices, utility rates, and raw material unit costs. The model is intended to be used as a tool to perform preliminary economic estimates that could be used to carry out simple screening analyses. The model`s current parameters are based on engineering judgments and are not reflective of any existing process; therefore, they should be carefully evaluated and modified if necessary to reflect the process under consideration. The accuracy and level of uncertainty of the estimated capital investment and operating costs are dependent on the accuracy and level of uncertainty of the model`s input parameters. The underlying methodology is capable of producing results accurate to within {+-} 30% of actual costs.

  19. Aerobic and Anaerobic Respiration in Profiles of Polesie Lubelskie Peatlands

    NASA Astrophysics Data System (ADS)

    Szafranek-Nakonieczna, Anna; Stêpniewska, Zofia

    2014-04-01

    Soil respiration is a very important factor influencing carbon deposition in peat and reflecting the intensity of soil organic matter decomposition, root respiration, and the ease of transporting gases to the surface. Carbon dioxide release from three different peat soil profiles (0-80 cm) of the Polesie Lubelskie Region (Eastern Poland) was analyzed under laboratory conditions. Peat samples were incubated at 5, 10, and 20°C in aerobic and anaerobic environments, and their CO2-evolution was analyzed up to 14 days. The respiration activity was found to be in the range of 0.013-0.497 g CO2 kg-1 DW d-1. The respiratory quotient was estimated to be in the range of 0.51-1.51, and the difference in respiration rates over 10°C ranged between 4.15 and 8.72 in aerobic and from 1.15 to 6.53 in anaerobic conditions. A strong influence of temperature, depth, the degree of peat decomposition, pH, and nitrate content on respiration activity was found. Lack of oxygen at low temperature caused higher respiration activity than under aerobic conditions. These results should be taken into account when the management of Polish peatlands is considered in the context of climate and carbon storage, and physicochemical properties of soil in relation to soil respiration activity are considered.

  20. Modeling a granule-based anaerobic ammonium oxidizing (ANAMMOX) process.

    PubMed

    Ni, Bing-Jie; Chen, You-Peng; Liu, Shao-Yang; Fang, Fang; Xie, Wen-Ming; Yu, Han-Qing

    2009-06-15

    A mathematical model was developed to describe the anaerobic ammonium oxidation (ANAMMOX) process in a granular upflow anaerobic sludge blanket (UASB) reactor. ANAMMOX granules were cultivated in the UASB reactor by seeding aerobic granules. The granule-based reactor had a great N-loading resistant capacity. The model simulation results on the 1-year reactor performance matched the experimental data well. The yield coefficient for the growth and the decay rate coefficient of the ANAMMOX granules were estimated to be 0.164 g COD g(-1) N and 0.00016 h(-1), respectively. With this model, the effects of process parameters on the reactor performance were evaluated. Results showed that the optimum granule diameter for the maximum N-removal should be between 1.0 and 1.3 mm and that the optimum N loading rate should be 0.8 kg N m(-3) d(-1). In addition, the substrate micro-profiles in the ANAMMOX granules were measured with a microelectrode to explore the diffusion dynamics within the granules, and the measured profiles matched the predicted results well. PMID:19280667